xref: /openbmc/linux/drivers/tty/synclink_gt.c (revision b38269ec)
1 // SPDX-License-Identifier: GPL-1.0+
2 /*
3  * Device driver for Microgate SyncLink GT serial adapters.
4  *
5  * written by Paul Fulghum for Microgate Corporation
6  * paulkf@microgate.com
7  *
8  * Microgate and SyncLink are trademarks of Microgate Corporation
9  *
10  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
11  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
12  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
13  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
14  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
15  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
16  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
17  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
18  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
19  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
20  * OF THE POSSIBILITY OF SUCH DAMAGE.
21  */
22 
23 /*
24  * DEBUG OUTPUT DEFINITIONS
25  *
26  * uncomment lines below to enable specific types of debug output
27  *
28  * DBGINFO   information - most verbose output
29  * DBGERR    serious errors
30  * DBGBH     bottom half service routine debugging
31  * DBGISR    interrupt service routine debugging
32  * DBGDATA   output receive and transmit data
33  * DBGTBUF   output transmit DMA buffers and registers
34  * DBGRBUF   output receive DMA buffers and registers
35  */
36 
37 #define DBGINFO(fmt) if (debug_level >= DEBUG_LEVEL_INFO) printk fmt
38 #define DBGERR(fmt) if (debug_level >= DEBUG_LEVEL_ERROR) printk fmt
39 #define DBGBH(fmt) if (debug_level >= DEBUG_LEVEL_BH) printk fmt
40 #define DBGISR(fmt) if (debug_level >= DEBUG_LEVEL_ISR) printk fmt
41 #define DBGDATA(info, buf, size, label) if (debug_level >= DEBUG_LEVEL_DATA) trace_block((info), (buf), (size), (label))
42 /*#define DBGTBUF(info) dump_tbufs(info)*/
43 /*#define DBGRBUF(info) dump_rbufs(info)*/
44 
45 
46 #include <linux/module.h>
47 #include <linux/errno.h>
48 #include <linux/signal.h>
49 #include <linux/sched.h>
50 #include <linux/timer.h>
51 #include <linux/interrupt.h>
52 #include <linux/pci.h>
53 #include <linux/tty.h>
54 #include <linux/tty_flip.h>
55 #include <linux/serial.h>
56 #include <linux/major.h>
57 #include <linux/string.h>
58 #include <linux/fcntl.h>
59 #include <linux/ptrace.h>
60 #include <linux/ioport.h>
61 #include <linux/mm.h>
62 #include <linux/seq_file.h>
63 #include <linux/slab.h>
64 #include <linux/netdevice.h>
65 #include <linux/vmalloc.h>
66 #include <linux/init.h>
67 #include <linux/delay.h>
68 #include <linux/ioctl.h>
69 #include <linux/termios.h>
70 #include <linux/bitops.h>
71 #include <linux/workqueue.h>
72 #include <linux/hdlc.h>
73 #include <linux/synclink.h>
74 
75 #include <asm/io.h>
76 #include <asm/irq.h>
77 #include <asm/dma.h>
78 #include <asm/types.h>
79 #include <linux/uaccess.h>
80 
81 #if defined(CONFIG_HDLC) || (defined(CONFIG_HDLC_MODULE) && defined(CONFIG_SYNCLINK_GT_MODULE))
82 #define SYNCLINK_GENERIC_HDLC 1
83 #else
84 #define SYNCLINK_GENERIC_HDLC 0
85 #endif
86 
87 /*
88  * module identification
89  */
90 static char *driver_name     = "SyncLink GT";
91 static char *slgt_driver_name = "synclink_gt";
92 static char *tty_dev_prefix  = "ttySLG";
93 MODULE_LICENSE("GPL");
94 #define MGSL_MAGIC 0x5401
95 #define MAX_DEVICES 32
96 
97 static const struct pci_device_id pci_table[] = {
98 	{PCI_VENDOR_ID_MICROGATE, SYNCLINK_GT_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
99 	{PCI_VENDOR_ID_MICROGATE, SYNCLINK_GT2_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
100 	{PCI_VENDOR_ID_MICROGATE, SYNCLINK_GT4_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
101 	{PCI_VENDOR_ID_MICROGATE, SYNCLINK_AC_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
102 	{0,}, /* terminate list */
103 };
104 MODULE_DEVICE_TABLE(pci, pci_table);
105 
106 static int  init_one(struct pci_dev *dev,const struct pci_device_id *ent);
107 static void remove_one(struct pci_dev *dev);
108 static struct pci_driver pci_driver = {
109 	.name		= "synclink_gt",
110 	.id_table	= pci_table,
111 	.probe		= init_one,
112 	.remove		= remove_one,
113 };
114 
115 static bool pci_registered;
116 
117 /*
118  * module configuration and status
119  */
120 static struct slgt_info *slgt_device_list;
121 static int slgt_device_count;
122 
123 static int ttymajor;
124 static int debug_level;
125 static int maxframe[MAX_DEVICES];
126 
127 module_param(ttymajor, int, 0);
128 module_param(debug_level, int, 0);
129 module_param_array(maxframe, int, NULL, 0);
130 
131 MODULE_PARM_DESC(ttymajor, "TTY major device number override: 0=auto assigned");
132 MODULE_PARM_DESC(debug_level, "Debug syslog output: 0=disabled, 1 to 5=increasing detail");
133 MODULE_PARM_DESC(maxframe, "Maximum frame size used by device (4096 to 65535)");
134 
135 /*
136  * tty support and callbacks
137  */
138 static struct tty_driver *serial_driver;
139 
140 static void wait_until_sent(struct tty_struct *tty, int timeout);
141 static void flush_buffer(struct tty_struct *tty);
142 static void tx_release(struct tty_struct *tty);
143 
144 /*
145  * generic HDLC support
146  */
147 #define dev_to_port(D) (dev_to_hdlc(D)->priv)
148 
149 
150 /*
151  * device specific structures, macros and functions
152  */
153 
154 #define SLGT_MAX_PORTS 4
155 #define SLGT_REG_SIZE  256
156 
157 /*
158  * conditional wait facility
159  */
160 struct cond_wait {
161 	struct cond_wait *next;
162 	wait_queue_head_t q;
163 	wait_queue_entry_t wait;
164 	unsigned int data;
165 };
166 static void flush_cond_wait(struct cond_wait **head);
167 
168 /*
169  * DMA buffer descriptor and access macros
170  */
171 struct slgt_desc
172 {
173 	__le16 count;
174 	__le16 status;
175 	__le32 pbuf;  /* physical address of data buffer */
176 	__le32 next;  /* physical address of next descriptor */
177 
178 	/* driver book keeping */
179 	char *buf;          /* virtual  address of data buffer */
180     	unsigned int pdesc; /* physical address of this descriptor */
181 	dma_addr_t buf_dma_addr;
182 	unsigned short buf_count;
183 };
184 
185 #define set_desc_buffer(a,b) (a).pbuf = cpu_to_le32((unsigned int)(b))
186 #define set_desc_next(a,b) (a).next   = cpu_to_le32((unsigned int)(b))
187 #define set_desc_count(a,b)(a).count  = cpu_to_le16((unsigned short)(b))
188 #define set_desc_eof(a,b)  (a).status = cpu_to_le16((b) ? (le16_to_cpu((a).status) | BIT0) : (le16_to_cpu((a).status) & ~BIT0))
189 #define set_desc_status(a, b) (a).status = cpu_to_le16((unsigned short)(b))
190 #define desc_count(a)      (le16_to_cpu((a).count))
191 #define desc_status(a)     (le16_to_cpu((a).status))
192 #define desc_complete(a)   (le16_to_cpu((a).status) & BIT15)
193 #define desc_eof(a)        (le16_to_cpu((a).status) & BIT2)
194 #define desc_crc_error(a)  (le16_to_cpu((a).status) & BIT1)
195 #define desc_abort(a)      (le16_to_cpu((a).status) & BIT0)
196 #define desc_residue(a)    ((le16_to_cpu((a).status) & 0x38) >> 3)
197 
198 struct _input_signal_events {
199 	int ri_up;
200 	int ri_down;
201 	int dsr_up;
202 	int dsr_down;
203 	int dcd_up;
204 	int dcd_down;
205 	int cts_up;
206 	int cts_down;
207 };
208 
209 /*
210  * device instance data structure
211  */
212 struct slgt_info {
213 	void *if_ptr;		/* General purpose pointer (used by SPPP) */
214 	struct tty_port port;
215 
216 	struct slgt_info *next_device;	/* device list link */
217 
218 	int magic;
219 
220 	char device_name[25];
221 	struct pci_dev *pdev;
222 
223 	int port_count;  /* count of ports on adapter */
224 	int adapter_num; /* adapter instance number */
225 	int port_num;    /* port instance number */
226 
227 	/* array of pointers to port contexts on this adapter */
228 	struct slgt_info *port_array[SLGT_MAX_PORTS];
229 
230 	int			line;		/* tty line instance number */
231 
232 	struct mgsl_icount	icount;
233 
234 	int			timeout;
235 	int			x_char;		/* xon/xoff character */
236 	unsigned int		read_status_mask;
237 	unsigned int 		ignore_status_mask;
238 
239 	wait_queue_head_t	status_event_wait_q;
240 	wait_queue_head_t	event_wait_q;
241 	struct timer_list	tx_timer;
242 	struct timer_list	rx_timer;
243 
244 	unsigned int            gpio_present;
245 	struct cond_wait        *gpio_wait_q;
246 
247 	spinlock_t lock;	/* spinlock for synchronizing with ISR */
248 
249 	struct work_struct task;
250 	u32 pending_bh;
251 	bool bh_requested;
252 	bool bh_running;
253 
254 	int isr_overflow;
255 	bool irq_requested;	/* true if IRQ requested */
256 	bool irq_occurred;	/* for diagnostics use */
257 
258 	/* device configuration */
259 
260 	unsigned int bus_type;
261 	unsigned int irq_level;
262 	unsigned long irq_flags;
263 
264 	unsigned char __iomem * reg_addr;  /* memory mapped registers address */
265 	u32 phys_reg_addr;
266 	bool reg_addr_requested;
267 
268 	MGSL_PARAMS params;       /* communications parameters */
269 	u32 idle_mode;
270 	u32 max_frame_size;       /* as set by device config */
271 
272 	unsigned int rbuf_fill_level;
273 	unsigned int rx_pio;
274 	unsigned int if_mode;
275 	unsigned int base_clock;
276 	unsigned int xsync;
277 	unsigned int xctrl;
278 
279 	/* device status */
280 
281 	bool rx_enabled;
282 	bool rx_restart;
283 
284 	bool tx_enabled;
285 	bool tx_active;
286 
287 	unsigned char signals;    /* serial signal states */
288 	int init_error;  /* initialization error */
289 
290 	unsigned char *tx_buf;
291 	int tx_count;
292 
293 	char *flag_buf;
294 	bool drop_rts_on_tx_done;
295 	struct	_input_signal_events	input_signal_events;
296 
297 	int dcd_chkcount;	/* check counts to prevent */
298 	int cts_chkcount;	/* too many IRQs if a signal */
299 	int dsr_chkcount;	/* is floating */
300 	int ri_chkcount;
301 
302 	char *bufs;		/* virtual address of DMA buffer lists */
303 	dma_addr_t bufs_dma_addr; /* physical address of buffer descriptors */
304 
305 	unsigned int rbuf_count;
306 	struct slgt_desc *rbufs;
307 	unsigned int rbuf_current;
308 	unsigned int rbuf_index;
309 	unsigned int rbuf_fill_index;
310 	unsigned short rbuf_fill_count;
311 
312 	unsigned int tbuf_count;
313 	struct slgt_desc *tbufs;
314 	unsigned int tbuf_current;
315 	unsigned int tbuf_start;
316 
317 	unsigned char *tmp_rbuf;
318 	unsigned int tmp_rbuf_count;
319 
320 	/* SPPP/Cisco HDLC device parts */
321 
322 	int netcount;
323 	spinlock_t netlock;
324 #if SYNCLINK_GENERIC_HDLC
325 	struct net_device *netdev;
326 #endif
327 
328 };
329 
330 static MGSL_PARAMS default_params = {
331 	.mode            = MGSL_MODE_HDLC,
332 	.loopback        = 0,
333 	.flags           = HDLC_FLAG_UNDERRUN_ABORT15,
334 	.encoding        = HDLC_ENCODING_NRZI_SPACE,
335 	.clock_speed     = 0,
336 	.addr_filter     = 0xff,
337 	.crc_type        = HDLC_CRC_16_CCITT,
338 	.preamble_length = HDLC_PREAMBLE_LENGTH_8BITS,
339 	.preamble        = HDLC_PREAMBLE_PATTERN_NONE,
340 	.data_rate       = 9600,
341 	.data_bits       = 8,
342 	.stop_bits       = 1,
343 	.parity          = ASYNC_PARITY_NONE
344 };
345 
346 
347 #define BH_RECEIVE  1
348 #define BH_TRANSMIT 2
349 #define BH_STATUS   4
350 #define IO_PIN_SHUTDOWN_LIMIT 100
351 
352 #define DMABUFSIZE 256
353 #define DESC_LIST_SIZE 4096
354 
355 #define MASK_PARITY  BIT1
356 #define MASK_FRAMING BIT0
357 #define MASK_BREAK   BIT14
358 #define MASK_OVERRUN BIT4
359 
360 #define GSR   0x00 /* global status */
361 #define JCR   0x04 /* JTAG control */
362 #define IODR  0x08 /* GPIO direction */
363 #define IOER  0x0c /* GPIO interrupt enable */
364 #define IOVR  0x10 /* GPIO value */
365 #define IOSR  0x14 /* GPIO interrupt status */
366 #define TDR   0x80 /* tx data */
367 #define RDR   0x80 /* rx data */
368 #define TCR   0x82 /* tx control */
369 #define TIR   0x84 /* tx idle */
370 #define TPR   0x85 /* tx preamble */
371 #define RCR   0x86 /* rx control */
372 #define VCR   0x88 /* V.24 control */
373 #define CCR   0x89 /* clock control */
374 #define BDR   0x8a /* baud divisor */
375 #define SCR   0x8c /* serial control */
376 #define SSR   0x8e /* serial status */
377 #define RDCSR 0x90 /* rx DMA control/status */
378 #define TDCSR 0x94 /* tx DMA control/status */
379 #define RDDAR 0x98 /* rx DMA descriptor address */
380 #define TDDAR 0x9c /* tx DMA descriptor address */
381 #define XSR   0x40 /* extended sync pattern */
382 #define XCR   0x44 /* extended control */
383 
384 #define RXIDLE      BIT14
385 #define RXBREAK     BIT14
386 #define IRQ_TXDATA  BIT13
387 #define IRQ_TXIDLE  BIT12
388 #define IRQ_TXUNDER BIT11 /* HDLC */
389 #define IRQ_RXDATA  BIT10
390 #define IRQ_RXIDLE  BIT9  /* HDLC */
391 #define IRQ_RXBREAK BIT9  /* async */
392 #define IRQ_RXOVER  BIT8
393 #define IRQ_DSR     BIT7
394 #define IRQ_CTS     BIT6
395 #define IRQ_DCD     BIT5
396 #define IRQ_RI      BIT4
397 #define IRQ_ALL     0x3ff0
398 #define IRQ_MASTER  BIT0
399 
400 #define slgt_irq_on(info, mask) \
401 	wr_reg16((info), SCR, (unsigned short)(rd_reg16((info), SCR) | (mask)))
402 #define slgt_irq_off(info, mask) \
403 	wr_reg16((info), SCR, (unsigned short)(rd_reg16((info), SCR) & ~(mask)))
404 
405 static __u8  rd_reg8(struct slgt_info *info, unsigned int addr);
406 static void  wr_reg8(struct slgt_info *info, unsigned int addr, __u8 value);
407 static __u16 rd_reg16(struct slgt_info *info, unsigned int addr);
408 static void  wr_reg16(struct slgt_info *info, unsigned int addr, __u16 value);
409 static __u32 rd_reg32(struct slgt_info *info, unsigned int addr);
410 static void  wr_reg32(struct slgt_info *info, unsigned int addr, __u32 value);
411 
412 static void  msc_set_vcr(struct slgt_info *info);
413 
414 static int  startup(struct slgt_info *info);
415 static int  block_til_ready(struct tty_struct *tty, struct file * filp,struct slgt_info *info);
416 static void shutdown(struct slgt_info *info);
417 static void program_hw(struct slgt_info *info);
418 static void change_params(struct slgt_info *info);
419 
420 static int  adapter_test(struct slgt_info *info);
421 
422 static void reset_port(struct slgt_info *info);
423 static void async_mode(struct slgt_info *info);
424 static void sync_mode(struct slgt_info *info);
425 
426 static void rx_stop(struct slgt_info *info);
427 static void rx_start(struct slgt_info *info);
428 static void reset_rbufs(struct slgt_info *info);
429 static void free_rbufs(struct slgt_info *info, unsigned int first, unsigned int last);
430 static bool rx_get_frame(struct slgt_info *info);
431 static bool rx_get_buf(struct slgt_info *info);
432 
433 static void tx_start(struct slgt_info *info);
434 static void tx_stop(struct slgt_info *info);
435 static void tx_set_idle(struct slgt_info *info);
436 static unsigned int tbuf_bytes(struct slgt_info *info);
437 static void reset_tbufs(struct slgt_info *info);
438 static void tdma_reset(struct slgt_info *info);
439 static bool tx_load(struct slgt_info *info, const char *buf, unsigned int count);
440 
441 static void get_signals(struct slgt_info *info);
442 static void set_signals(struct slgt_info *info);
443 static void set_rate(struct slgt_info *info, u32 data_rate);
444 
445 static void bh_transmit(struct slgt_info *info);
446 static void isr_txeom(struct slgt_info *info, unsigned short status);
447 
448 static void tx_timeout(struct timer_list *t);
449 static void rx_timeout(struct timer_list *t);
450 
451 /*
452  * ioctl handlers
453  */
454 static int  get_stats(struct slgt_info *info, struct mgsl_icount __user *user_icount);
455 static int  get_params(struct slgt_info *info, MGSL_PARAMS __user *params);
456 static int  set_params(struct slgt_info *info, MGSL_PARAMS __user *params);
457 static int  get_txidle(struct slgt_info *info, int __user *idle_mode);
458 static int  set_txidle(struct slgt_info *info, int idle_mode);
459 static int  tx_enable(struct slgt_info *info, int enable);
460 static int  tx_abort(struct slgt_info *info);
461 static int  rx_enable(struct slgt_info *info, int enable);
462 static int  modem_input_wait(struct slgt_info *info,int arg);
463 static int  wait_mgsl_event(struct slgt_info *info, int __user *mask_ptr);
464 static int  get_interface(struct slgt_info *info, int __user *if_mode);
465 static int  set_interface(struct slgt_info *info, int if_mode);
466 static int  set_gpio(struct slgt_info *info, struct gpio_desc __user *gpio);
467 static int  get_gpio(struct slgt_info *info, struct gpio_desc __user *gpio);
468 static int  wait_gpio(struct slgt_info *info, struct gpio_desc __user *gpio);
469 static int  get_xsync(struct slgt_info *info, int __user *if_mode);
470 static int  set_xsync(struct slgt_info *info, int if_mode);
471 static int  get_xctrl(struct slgt_info *info, int __user *if_mode);
472 static int  set_xctrl(struct slgt_info *info, int if_mode);
473 
474 /*
475  * driver functions
476  */
477 static void release_resources(struct slgt_info *info);
478 
479 /*
480  * DEBUG OUTPUT CODE
481  */
482 #ifndef DBGINFO
483 #define DBGINFO(fmt)
484 #endif
485 #ifndef DBGERR
486 #define DBGERR(fmt)
487 #endif
488 #ifndef DBGBH
489 #define DBGBH(fmt)
490 #endif
491 #ifndef DBGISR
492 #define DBGISR(fmt)
493 #endif
494 
495 #ifdef DBGDATA
496 static void trace_block(struct slgt_info *info, const char *data, int count, const char *label)
497 {
498 	int i;
499 	int linecount;
500 	printk("%s %s data:\n",info->device_name, label);
501 	while(count) {
502 		linecount = (count > 16) ? 16 : count;
503 		for(i=0; i < linecount; i++)
504 			printk("%02X ",(unsigned char)data[i]);
505 		for(;i<17;i++)
506 			printk("   ");
507 		for(i=0;i<linecount;i++) {
508 			if (data[i]>=040 && data[i]<=0176)
509 				printk("%c",data[i]);
510 			else
511 				printk(".");
512 		}
513 		printk("\n");
514 		data  += linecount;
515 		count -= linecount;
516 	}
517 }
518 #else
519 #define DBGDATA(info, buf, size, label)
520 #endif
521 
522 #ifdef DBGTBUF
523 static void dump_tbufs(struct slgt_info *info)
524 {
525 	int i;
526 	printk("tbuf_current=%d\n", info->tbuf_current);
527 	for (i=0 ; i < info->tbuf_count ; i++) {
528 		printk("%d: count=%04X status=%04X\n",
529 			i, le16_to_cpu(info->tbufs[i].count), le16_to_cpu(info->tbufs[i].status));
530 	}
531 }
532 #else
533 #define DBGTBUF(info)
534 #endif
535 
536 #ifdef DBGRBUF
537 static void dump_rbufs(struct slgt_info *info)
538 {
539 	int i;
540 	printk("rbuf_current=%d\n", info->rbuf_current);
541 	for (i=0 ; i < info->rbuf_count ; i++) {
542 		printk("%d: count=%04X status=%04X\n",
543 			i, le16_to_cpu(info->rbufs[i].count), le16_to_cpu(info->rbufs[i].status));
544 	}
545 }
546 #else
547 #define DBGRBUF(info)
548 #endif
549 
550 static inline int sanity_check(struct slgt_info *info, char *devname, const char *name)
551 {
552 #ifdef SANITY_CHECK
553 	if (!info) {
554 		printk("null struct slgt_info for (%s) in %s\n", devname, name);
555 		return 1;
556 	}
557 	if (info->magic != MGSL_MAGIC) {
558 		printk("bad magic number struct slgt_info (%s) in %s\n", devname, name);
559 		return 1;
560 	}
561 #else
562 	if (!info)
563 		return 1;
564 #endif
565 	return 0;
566 }
567 
568 /*
569  * line discipline callback wrappers
570  *
571  * The wrappers maintain line discipline references
572  * while calling into the line discipline.
573  *
574  * ldisc_receive_buf  - pass receive data to line discipline
575  */
576 static void ldisc_receive_buf(struct tty_struct *tty,
577 			      const __u8 *data, char *flags, int count)
578 {
579 	struct tty_ldisc *ld;
580 	if (!tty)
581 		return;
582 	ld = tty_ldisc_ref(tty);
583 	if (ld) {
584 		if (ld->ops->receive_buf)
585 			ld->ops->receive_buf(tty, data, flags, count);
586 		tty_ldisc_deref(ld);
587 	}
588 }
589 
590 /* tty callbacks */
591 
592 static int open(struct tty_struct *tty, struct file *filp)
593 {
594 	struct slgt_info *info;
595 	int retval, line;
596 	unsigned long flags;
597 
598 	line = tty->index;
599 	if (line >= slgt_device_count) {
600 		DBGERR(("%s: open with invalid line #%d.\n", driver_name, line));
601 		return -ENODEV;
602 	}
603 
604 	info = slgt_device_list;
605 	while(info && info->line != line)
606 		info = info->next_device;
607 	if (sanity_check(info, tty->name, "open"))
608 		return -ENODEV;
609 	if (info->init_error) {
610 		DBGERR(("%s init error=%d\n", info->device_name, info->init_error));
611 		return -ENODEV;
612 	}
613 
614 	tty->driver_data = info;
615 	info->port.tty = tty;
616 
617 	DBGINFO(("%s open, old ref count = %d\n", info->device_name, info->port.count));
618 
619 	mutex_lock(&info->port.mutex);
620 
621 	spin_lock_irqsave(&info->netlock, flags);
622 	if (info->netcount) {
623 		retval = -EBUSY;
624 		spin_unlock_irqrestore(&info->netlock, flags);
625 		mutex_unlock(&info->port.mutex);
626 		goto cleanup;
627 	}
628 	info->port.count++;
629 	spin_unlock_irqrestore(&info->netlock, flags);
630 
631 	if (info->port.count == 1) {
632 		/* 1st open on this device, init hardware */
633 		retval = startup(info);
634 		if (retval < 0) {
635 			mutex_unlock(&info->port.mutex);
636 			goto cleanup;
637 		}
638 	}
639 	mutex_unlock(&info->port.mutex);
640 	retval = block_til_ready(tty, filp, info);
641 	if (retval) {
642 		DBGINFO(("%s block_til_ready rc=%d\n", info->device_name, retval));
643 		goto cleanup;
644 	}
645 
646 	retval = 0;
647 
648 cleanup:
649 	if (retval) {
650 		if (tty->count == 1)
651 			info->port.tty = NULL; /* tty layer will release tty struct */
652 		if(info->port.count)
653 			info->port.count--;
654 	}
655 
656 	DBGINFO(("%s open rc=%d\n", info->device_name, retval));
657 	return retval;
658 }
659 
660 static void close(struct tty_struct *tty, struct file *filp)
661 {
662 	struct slgt_info *info = tty->driver_data;
663 
664 	if (sanity_check(info, tty->name, "close"))
665 		return;
666 	DBGINFO(("%s close entry, count=%d\n", info->device_name, info->port.count));
667 
668 	if (tty_port_close_start(&info->port, tty, filp) == 0)
669 		goto cleanup;
670 
671 	mutex_lock(&info->port.mutex);
672 	if (tty_port_initialized(&info->port))
673  		wait_until_sent(tty, info->timeout);
674 	flush_buffer(tty);
675 	tty_ldisc_flush(tty);
676 
677 	shutdown(info);
678 	mutex_unlock(&info->port.mutex);
679 
680 	tty_port_close_end(&info->port, tty);
681 	info->port.tty = NULL;
682 cleanup:
683 	DBGINFO(("%s close exit, count=%d\n", tty->driver->name, info->port.count));
684 }
685 
686 static void hangup(struct tty_struct *tty)
687 {
688 	struct slgt_info *info = tty->driver_data;
689 	unsigned long flags;
690 
691 	if (sanity_check(info, tty->name, "hangup"))
692 		return;
693 	DBGINFO(("%s hangup\n", info->device_name));
694 
695 	flush_buffer(tty);
696 
697 	mutex_lock(&info->port.mutex);
698 	shutdown(info);
699 
700 	spin_lock_irqsave(&info->port.lock, flags);
701 	info->port.count = 0;
702 	info->port.tty = NULL;
703 	spin_unlock_irqrestore(&info->port.lock, flags);
704 	tty_port_set_active(&info->port, 0);
705 	mutex_unlock(&info->port.mutex);
706 
707 	wake_up_interruptible(&info->port.open_wait);
708 }
709 
710 static void set_termios(struct tty_struct *tty, struct ktermios *old_termios)
711 {
712 	struct slgt_info *info = tty->driver_data;
713 	unsigned long flags;
714 
715 	DBGINFO(("%s set_termios\n", tty->driver->name));
716 
717 	change_params(info);
718 
719 	/* Handle transition to B0 status */
720 	if ((old_termios->c_cflag & CBAUD) && !C_BAUD(tty)) {
721 		info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
722 		spin_lock_irqsave(&info->lock,flags);
723 		set_signals(info);
724 		spin_unlock_irqrestore(&info->lock,flags);
725 	}
726 
727 	/* Handle transition away from B0 status */
728 	if (!(old_termios->c_cflag & CBAUD) && C_BAUD(tty)) {
729 		info->signals |= SerialSignal_DTR;
730 		if (!C_CRTSCTS(tty) || !tty_throttled(tty))
731 			info->signals |= SerialSignal_RTS;
732 		spin_lock_irqsave(&info->lock,flags);
733 	 	set_signals(info);
734 		spin_unlock_irqrestore(&info->lock,flags);
735 	}
736 
737 	/* Handle turning off CRTSCTS */
738 	if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
739 		tty->hw_stopped = 0;
740 		tx_release(tty);
741 	}
742 }
743 
744 static void update_tx_timer(struct slgt_info *info)
745 {
746 	/*
747 	 * use worst case speed of 1200bps to calculate transmit timeout
748 	 * based on data in buffers (tbuf_bytes) and FIFO (128 bytes)
749 	 */
750 	if (info->params.mode == MGSL_MODE_HDLC) {
751 		int timeout  = (tbuf_bytes(info) * 7) + 1000;
752 		mod_timer(&info->tx_timer, jiffies + msecs_to_jiffies(timeout));
753 	}
754 }
755 
756 static int write(struct tty_struct *tty,
757 		 const unsigned char *buf, int count)
758 {
759 	int ret = 0;
760 	struct slgt_info *info = tty->driver_data;
761 	unsigned long flags;
762 
763 	if (sanity_check(info, tty->name, "write"))
764 		return -EIO;
765 
766 	DBGINFO(("%s write count=%d\n", info->device_name, count));
767 
768 	if (!info->tx_buf || (count > info->max_frame_size))
769 		return -EIO;
770 
771 	if (!count || tty->flow.stopped || tty->hw_stopped)
772 		return 0;
773 
774 	spin_lock_irqsave(&info->lock, flags);
775 
776 	if (info->tx_count) {
777 		/* send accumulated data from send_char() */
778 		if (!tx_load(info, info->tx_buf, info->tx_count))
779 			goto cleanup;
780 		info->tx_count = 0;
781 	}
782 
783 	if (tx_load(info, buf, count))
784 		ret = count;
785 
786 cleanup:
787 	spin_unlock_irqrestore(&info->lock, flags);
788 	DBGINFO(("%s write rc=%d\n", info->device_name, ret));
789 	return ret;
790 }
791 
792 static int put_char(struct tty_struct *tty, unsigned char ch)
793 {
794 	struct slgt_info *info = tty->driver_data;
795 	unsigned long flags;
796 	int ret = 0;
797 
798 	if (sanity_check(info, tty->name, "put_char"))
799 		return 0;
800 	DBGINFO(("%s put_char(%d)\n", info->device_name, ch));
801 	if (!info->tx_buf)
802 		return 0;
803 	spin_lock_irqsave(&info->lock,flags);
804 	if (info->tx_count < info->max_frame_size) {
805 		info->tx_buf[info->tx_count++] = ch;
806 		ret = 1;
807 	}
808 	spin_unlock_irqrestore(&info->lock,flags);
809 	return ret;
810 }
811 
812 static void send_xchar(struct tty_struct *tty, char ch)
813 {
814 	struct slgt_info *info = tty->driver_data;
815 	unsigned long flags;
816 
817 	if (sanity_check(info, tty->name, "send_xchar"))
818 		return;
819 	DBGINFO(("%s send_xchar(%d)\n", info->device_name, ch));
820 	info->x_char = ch;
821 	if (ch) {
822 		spin_lock_irqsave(&info->lock,flags);
823 		if (!info->tx_enabled)
824 		 	tx_start(info);
825 		spin_unlock_irqrestore(&info->lock,flags);
826 	}
827 }
828 
829 static void wait_until_sent(struct tty_struct *tty, int timeout)
830 {
831 	struct slgt_info *info = tty->driver_data;
832 	unsigned long orig_jiffies, char_time;
833 
834 	if (!info )
835 		return;
836 	if (sanity_check(info, tty->name, "wait_until_sent"))
837 		return;
838 	DBGINFO(("%s wait_until_sent entry\n", info->device_name));
839 	if (!tty_port_initialized(&info->port))
840 		goto exit;
841 
842 	orig_jiffies = jiffies;
843 
844 	/* Set check interval to 1/5 of estimated time to
845 	 * send a character, and make it at least 1. The check
846 	 * interval should also be less than the timeout.
847 	 * Note: use tight timings here to satisfy the NIST-PCTS.
848 	 */
849 
850 	if (info->params.data_rate) {
851 	       	char_time = info->timeout/(32 * 5);
852 		if (!char_time)
853 			char_time++;
854 	} else
855 		char_time = 1;
856 
857 	if (timeout)
858 		char_time = min_t(unsigned long, char_time, timeout);
859 
860 	while (info->tx_active) {
861 		msleep_interruptible(jiffies_to_msecs(char_time));
862 		if (signal_pending(current))
863 			break;
864 		if (timeout && time_after(jiffies, orig_jiffies + timeout))
865 			break;
866 	}
867 exit:
868 	DBGINFO(("%s wait_until_sent exit\n", info->device_name));
869 }
870 
871 static unsigned int write_room(struct tty_struct *tty)
872 {
873 	struct slgt_info *info = tty->driver_data;
874 	unsigned int ret;
875 
876 	if (sanity_check(info, tty->name, "write_room"))
877 		return 0;
878 	ret = (info->tx_active) ? 0 : HDLC_MAX_FRAME_SIZE;
879 	DBGINFO(("%s write_room=%u\n", info->device_name, ret));
880 	return ret;
881 }
882 
883 static void flush_chars(struct tty_struct *tty)
884 {
885 	struct slgt_info *info = tty->driver_data;
886 	unsigned long flags;
887 
888 	if (sanity_check(info, tty->name, "flush_chars"))
889 		return;
890 	DBGINFO(("%s flush_chars entry tx_count=%d\n", info->device_name, info->tx_count));
891 
892 	if (info->tx_count <= 0 || tty->flow.stopped ||
893 	    tty->hw_stopped || !info->tx_buf)
894 		return;
895 
896 	DBGINFO(("%s flush_chars start transmit\n", info->device_name));
897 
898 	spin_lock_irqsave(&info->lock,flags);
899 	if (info->tx_count && tx_load(info, info->tx_buf, info->tx_count))
900 		info->tx_count = 0;
901 	spin_unlock_irqrestore(&info->lock,flags);
902 }
903 
904 static void flush_buffer(struct tty_struct *tty)
905 {
906 	struct slgt_info *info = tty->driver_data;
907 	unsigned long flags;
908 
909 	if (sanity_check(info, tty->name, "flush_buffer"))
910 		return;
911 	DBGINFO(("%s flush_buffer\n", info->device_name));
912 
913 	spin_lock_irqsave(&info->lock, flags);
914 	info->tx_count = 0;
915 	spin_unlock_irqrestore(&info->lock, flags);
916 
917 	tty_wakeup(tty);
918 }
919 
920 /*
921  * throttle (stop) transmitter
922  */
923 static void tx_hold(struct tty_struct *tty)
924 {
925 	struct slgt_info *info = tty->driver_data;
926 	unsigned long flags;
927 
928 	if (sanity_check(info, tty->name, "tx_hold"))
929 		return;
930 	DBGINFO(("%s tx_hold\n", info->device_name));
931 	spin_lock_irqsave(&info->lock,flags);
932 	if (info->tx_enabled && info->params.mode == MGSL_MODE_ASYNC)
933 	 	tx_stop(info);
934 	spin_unlock_irqrestore(&info->lock,flags);
935 }
936 
937 /*
938  * release (start) transmitter
939  */
940 static void tx_release(struct tty_struct *tty)
941 {
942 	struct slgt_info *info = tty->driver_data;
943 	unsigned long flags;
944 
945 	if (sanity_check(info, tty->name, "tx_release"))
946 		return;
947 	DBGINFO(("%s tx_release\n", info->device_name));
948 	spin_lock_irqsave(&info->lock, flags);
949 	if (info->tx_count && tx_load(info, info->tx_buf, info->tx_count))
950 		info->tx_count = 0;
951 	spin_unlock_irqrestore(&info->lock, flags);
952 }
953 
954 /*
955  * Service an IOCTL request
956  *
957  * Arguments
958  *
959  * 	tty	pointer to tty instance data
960  * 	cmd	IOCTL command code
961  * 	arg	command argument/context
962  *
963  * Return 0 if success, otherwise error code
964  */
965 static int ioctl(struct tty_struct *tty,
966 		 unsigned int cmd, unsigned long arg)
967 {
968 	struct slgt_info *info = tty->driver_data;
969 	void __user *argp = (void __user *)arg;
970 	int ret;
971 
972 	if (sanity_check(info, tty->name, "ioctl"))
973 		return -ENODEV;
974 	DBGINFO(("%s ioctl() cmd=%08X\n", info->device_name, cmd));
975 
976 	if (cmd != TIOCMIWAIT) {
977 		if (tty_io_error(tty))
978 		    return -EIO;
979 	}
980 
981 	switch (cmd) {
982 	case MGSL_IOCWAITEVENT:
983 		return wait_mgsl_event(info, argp);
984 	case TIOCMIWAIT:
985 		return modem_input_wait(info,(int)arg);
986 	case MGSL_IOCSGPIO:
987 		return set_gpio(info, argp);
988 	case MGSL_IOCGGPIO:
989 		return get_gpio(info, argp);
990 	case MGSL_IOCWAITGPIO:
991 		return wait_gpio(info, argp);
992 	case MGSL_IOCGXSYNC:
993 		return get_xsync(info, argp);
994 	case MGSL_IOCSXSYNC:
995 		return set_xsync(info, (int)arg);
996 	case MGSL_IOCGXCTRL:
997 		return get_xctrl(info, argp);
998 	case MGSL_IOCSXCTRL:
999 		return set_xctrl(info, (int)arg);
1000 	}
1001 	mutex_lock(&info->port.mutex);
1002 	switch (cmd) {
1003 	case MGSL_IOCGPARAMS:
1004 		ret = get_params(info, argp);
1005 		break;
1006 	case MGSL_IOCSPARAMS:
1007 		ret = set_params(info, argp);
1008 		break;
1009 	case MGSL_IOCGTXIDLE:
1010 		ret = get_txidle(info, argp);
1011 		break;
1012 	case MGSL_IOCSTXIDLE:
1013 		ret = set_txidle(info, (int)arg);
1014 		break;
1015 	case MGSL_IOCTXENABLE:
1016 		ret = tx_enable(info, (int)arg);
1017 		break;
1018 	case MGSL_IOCRXENABLE:
1019 		ret = rx_enable(info, (int)arg);
1020 		break;
1021 	case MGSL_IOCTXABORT:
1022 		ret = tx_abort(info);
1023 		break;
1024 	case MGSL_IOCGSTATS:
1025 		ret = get_stats(info, argp);
1026 		break;
1027 	case MGSL_IOCGIF:
1028 		ret = get_interface(info, argp);
1029 		break;
1030 	case MGSL_IOCSIF:
1031 		ret = set_interface(info,(int)arg);
1032 		break;
1033 	default:
1034 		ret = -ENOIOCTLCMD;
1035 	}
1036 	mutex_unlock(&info->port.mutex);
1037 	return ret;
1038 }
1039 
1040 static int get_icount(struct tty_struct *tty,
1041 				struct serial_icounter_struct *icount)
1042 
1043 {
1044 	struct slgt_info *info = tty->driver_data;
1045 	struct mgsl_icount cnow;	/* kernel counter temps */
1046 	unsigned long flags;
1047 
1048 	spin_lock_irqsave(&info->lock,flags);
1049 	cnow = info->icount;
1050 	spin_unlock_irqrestore(&info->lock,flags);
1051 
1052 	icount->cts = cnow.cts;
1053 	icount->dsr = cnow.dsr;
1054 	icount->rng = cnow.rng;
1055 	icount->dcd = cnow.dcd;
1056 	icount->rx = cnow.rx;
1057 	icount->tx = cnow.tx;
1058 	icount->frame = cnow.frame;
1059 	icount->overrun = cnow.overrun;
1060 	icount->parity = cnow.parity;
1061 	icount->brk = cnow.brk;
1062 	icount->buf_overrun = cnow.buf_overrun;
1063 
1064 	return 0;
1065 }
1066 
1067 /*
1068  * support for 32 bit ioctl calls on 64 bit systems
1069  */
1070 #ifdef CONFIG_COMPAT
1071 static long get_params32(struct slgt_info *info, struct MGSL_PARAMS32 __user *user_params)
1072 {
1073 	struct MGSL_PARAMS32 tmp_params;
1074 
1075 	DBGINFO(("%s get_params32\n", info->device_name));
1076 	memset(&tmp_params, 0, sizeof(tmp_params));
1077 	tmp_params.mode            = (compat_ulong_t)info->params.mode;
1078 	tmp_params.loopback        = info->params.loopback;
1079 	tmp_params.flags           = info->params.flags;
1080 	tmp_params.encoding        = info->params.encoding;
1081 	tmp_params.clock_speed     = (compat_ulong_t)info->params.clock_speed;
1082 	tmp_params.addr_filter     = info->params.addr_filter;
1083 	tmp_params.crc_type        = info->params.crc_type;
1084 	tmp_params.preamble_length = info->params.preamble_length;
1085 	tmp_params.preamble        = info->params.preamble;
1086 	tmp_params.data_rate       = (compat_ulong_t)info->params.data_rate;
1087 	tmp_params.data_bits       = info->params.data_bits;
1088 	tmp_params.stop_bits       = info->params.stop_bits;
1089 	tmp_params.parity          = info->params.parity;
1090 	if (copy_to_user(user_params, &tmp_params, sizeof(struct MGSL_PARAMS32)))
1091 		return -EFAULT;
1092 	return 0;
1093 }
1094 
1095 static long set_params32(struct slgt_info *info, struct MGSL_PARAMS32 __user *new_params)
1096 {
1097 	struct MGSL_PARAMS32 tmp_params;
1098 
1099 	DBGINFO(("%s set_params32\n", info->device_name));
1100 	if (copy_from_user(&tmp_params, new_params, sizeof(struct MGSL_PARAMS32)))
1101 		return -EFAULT;
1102 
1103 	spin_lock(&info->lock);
1104 	if (tmp_params.mode == MGSL_MODE_BASE_CLOCK) {
1105 		info->base_clock = tmp_params.clock_speed;
1106 	} else {
1107 		info->params.mode            = tmp_params.mode;
1108 		info->params.loopback        = tmp_params.loopback;
1109 		info->params.flags           = tmp_params.flags;
1110 		info->params.encoding        = tmp_params.encoding;
1111 		info->params.clock_speed     = tmp_params.clock_speed;
1112 		info->params.addr_filter     = tmp_params.addr_filter;
1113 		info->params.crc_type        = tmp_params.crc_type;
1114 		info->params.preamble_length = tmp_params.preamble_length;
1115 		info->params.preamble        = tmp_params.preamble;
1116 		info->params.data_rate       = tmp_params.data_rate;
1117 		info->params.data_bits       = tmp_params.data_bits;
1118 		info->params.stop_bits       = tmp_params.stop_bits;
1119 		info->params.parity          = tmp_params.parity;
1120 	}
1121 	spin_unlock(&info->lock);
1122 
1123 	program_hw(info);
1124 
1125 	return 0;
1126 }
1127 
1128 static long slgt_compat_ioctl(struct tty_struct *tty,
1129 			 unsigned int cmd, unsigned long arg)
1130 {
1131 	struct slgt_info *info = tty->driver_data;
1132 	int rc;
1133 
1134 	if (sanity_check(info, tty->name, "compat_ioctl"))
1135 		return -ENODEV;
1136 	DBGINFO(("%s compat_ioctl() cmd=%08X\n", info->device_name, cmd));
1137 
1138 	switch (cmd) {
1139 	case MGSL_IOCSPARAMS32:
1140 		rc = set_params32(info, compat_ptr(arg));
1141 		break;
1142 
1143 	case MGSL_IOCGPARAMS32:
1144 		rc = get_params32(info, compat_ptr(arg));
1145 		break;
1146 
1147 	case MGSL_IOCGPARAMS:
1148 	case MGSL_IOCSPARAMS:
1149 	case MGSL_IOCGTXIDLE:
1150 	case MGSL_IOCGSTATS:
1151 	case MGSL_IOCWAITEVENT:
1152 	case MGSL_IOCGIF:
1153 	case MGSL_IOCSGPIO:
1154 	case MGSL_IOCGGPIO:
1155 	case MGSL_IOCWAITGPIO:
1156 	case MGSL_IOCGXSYNC:
1157 	case MGSL_IOCGXCTRL:
1158 		rc = ioctl(tty, cmd, (unsigned long)compat_ptr(arg));
1159 		break;
1160 	default:
1161 		rc = ioctl(tty, cmd, arg);
1162 	}
1163 	DBGINFO(("%s compat_ioctl() cmd=%08X rc=%d\n", info->device_name, cmd, rc));
1164 	return rc;
1165 }
1166 #else
1167 #define slgt_compat_ioctl NULL
1168 #endif /* ifdef CONFIG_COMPAT */
1169 
1170 /*
1171  * proc fs support
1172  */
1173 static inline void line_info(struct seq_file *m, struct slgt_info *info)
1174 {
1175 	char stat_buf[30];
1176 	unsigned long flags;
1177 
1178 	seq_printf(m, "%s: IO=%08X IRQ=%d MaxFrameSize=%u\n",
1179 		      info->device_name, info->phys_reg_addr,
1180 		      info->irq_level, info->max_frame_size);
1181 
1182 	/* output current serial signal states */
1183 	spin_lock_irqsave(&info->lock,flags);
1184 	get_signals(info);
1185 	spin_unlock_irqrestore(&info->lock,flags);
1186 
1187 	stat_buf[0] = 0;
1188 	stat_buf[1] = 0;
1189 	if (info->signals & SerialSignal_RTS)
1190 		strcat(stat_buf, "|RTS");
1191 	if (info->signals & SerialSignal_CTS)
1192 		strcat(stat_buf, "|CTS");
1193 	if (info->signals & SerialSignal_DTR)
1194 		strcat(stat_buf, "|DTR");
1195 	if (info->signals & SerialSignal_DSR)
1196 		strcat(stat_buf, "|DSR");
1197 	if (info->signals & SerialSignal_DCD)
1198 		strcat(stat_buf, "|CD");
1199 	if (info->signals & SerialSignal_RI)
1200 		strcat(stat_buf, "|RI");
1201 
1202 	if (info->params.mode != MGSL_MODE_ASYNC) {
1203 		seq_printf(m, "\tHDLC txok:%d rxok:%d",
1204 			       info->icount.txok, info->icount.rxok);
1205 		if (info->icount.txunder)
1206 			seq_printf(m, " txunder:%d", info->icount.txunder);
1207 		if (info->icount.txabort)
1208 			seq_printf(m, " txabort:%d", info->icount.txabort);
1209 		if (info->icount.rxshort)
1210 			seq_printf(m, " rxshort:%d", info->icount.rxshort);
1211 		if (info->icount.rxlong)
1212 			seq_printf(m, " rxlong:%d", info->icount.rxlong);
1213 		if (info->icount.rxover)
1214 			seq_printf(m, " rxover:%d", info->icount.rxover);
1215 		if (info->icount.rxcrc)
1216 			seq_printf(m, " rxcrc:%d", info->icount.rxcrc);
1217 	} else {
1218 		seq_printf(m, "\tASYNC tx:%d rx:%d",
1219 			       info->icount.tx, info->icount.rx);
1220 		if (info->icount.frame)
1221 			seq_printf(m, " fe:%d", info->icount.frame);
1222 		if (info->icount.parity)
1223 			seq_printf(m, " pe:%d", info->icount.parity);
1224 		if (info->icount.brk)
1225 			seq_printf(m, " brk:%d", info->icount.brk);
1226 		if (info->icount.overrun)
1227 			seq_printf(m, " oe:%d", info->icount.overrun);
1228 	}
1229 
1230 	/* Append serial signal status to end */
1231 	seq_printf(m, " %s\n", stat_buf+1);
1232 
1233 	seq_printf(m, "\ttxactive=%d bh_req=%d bh_run=%d pending_bh=%x\n",
1234 		       info->tx_active,info->bh_requested,info->bh_running,
1235 		       info->pending_bh);
1236 }
1237 
1238 /* Called to print information about devices
1239  */
1240 static int synclink_gt_proc_show(struct seq_file *m, void *v)
1241 {
1242 	struct slgt_info *info;
1243 
1244 	seq_puts(m, "synclink_gt driver\n");
1245 
1246 	info = slgt_device_list;
1247 	while( info ) {
1248 		line_info(m, info);
1249 		info = info->next_device;
1250 	}
1251 	return 0;
1252 }
1253 
1254 /*
1255  * return count of bytes in transmit buffer
1256  */
1257 static unsigned int chars_in_buffer(struct tty_struct *tty)
1258 {
1259 	struct slgt_info *info = tty->driver_data;
1260 	unsigned int count;
1261 	if (sanity_check(info, tty->name, "chars_in_buffer"))
1262 		return 0;
1263 	count = tbuf_bytes(info);
1264 	DBGINFO(("%s chars_in_buffer()=%u\n", info->device_name, count));
1265 	return count;
1266 }
1267 
1268 /*
1269  * signal remote device to throttle send data (our receive data)
1270  */
1271 static void throttle(struct tty_struct * tty)
1272 {
1273 	struct slgt_info *info = tty->driver_data;
1274 	unsigned long flags;
1275 
1276 	if (sanity_check(info, tty->name, "throttle"))
1277 		return;
1278 	DBGINFO(("%s throttle\n", info->device_name));
1279 	if (I_IXOFF(tty))
1280 		send_xchar(tty, STOP_CHAR(tty));
1281 	if (C_CRTSCTS(tty)) {
1282 		spin_lock_irqsave(&info->lock,flags);
1283 		info->signals &= ~SerialSignal_RTS;
1284 		set_signals(info);
1285 		spin_unlock_irqrestore(&info->lock,flags);
1286 	}
1287 }
1288 
1289 /*
1290  * signal remote device to stop throttling send data (our receive data)
1291  */
1292 static void unthrottle(struct tty_struct * tty)
1293 {
1294 	struct slgt_info *info = tty->driver_data;
1295 	unsigned long flags;
1296 
1297 	if (sanity_check(info, tty->name, "unthrottle"))
1298 		return;
1299 	DBGINFO(("%s unthrottle\n", info->device_name));
1300 	if (I_IXOFF(tty)) {
1301 		if (info->x_char)
1302 			info->x_char = 0;
1303 		else
1304 			send_xchar(tty, START_CHAR(tty));
1305 	}
1306 	if (C_CRTSCTS(tty)) {
1307 		spin_lock_irqsave(&info->lock,flags);
1308 		info->signals |= SerialSignal_RTS;
1309 		set_signals(info);
1310 		spin_unlock_irqrestore(&info->lock,flags);
1311 	}
1312 }
1313 
1314 /*
1315  * set or clear transmit break condition
1316  * break_state	-1=set break condition, 0=clear
1317  */
1318 static int set_break(struct tty_struct *tty, int break_state)
1319 {
1320 	struct slgt_info *info = tty->driver_data;
1321 	unsigned short value;
1322 	unsigned long flags;
1323 
1324 	if (sanity_check(info, tty->name, "set_break"))
1325 		return -EINVAL;
1326 	DBGINFO(("%s set_break(%d)\n", info->device_name, break_state));
1327 
1328 	spin_lock_irqsave(&info->lock,flags);
1329 	value = rd_reg16(info, TCR);
1330  	if (break_state == -1)
1331 		value |= BIT6;
1332 	else
1333 		value &= ~BIT6;
1334 	wr_reg16(info, TCR, value);
1335 	spin_unlock_irqrestore(&info->lock,flags);
1336 	return 0;
1337 }
1338 
1339 #if SYNCLINK_GENERIC_HDLC
1340 
1341 /**
1342  * hdlcdev_attach - called by generic HDLC layer when protocol selected (PPP, frame relay, etc.)
1343  * @dev:      pointer to network device structure
1344  * @encoding: serial encoding setting
1345  * @parity:   FCS setting
1346  *
1347  * Set encoding and frame check sequence (FCS) options.
1348  *
1349  * Return: 0 if success, otherwise error code
1350  */
1351 static int hdlcdev_attach(struct net_device *dev, unsigned short encoding,
1352 			  unsigned short parity)
1353 {
1354 	struct slgt_info *info = dev_to_port(dev);
1355 	unsigned char  new_encoding;
1356 	unsigned short new_crctype;
1357 
1358 	/* return error if TTY interface open */
1359 	if (info->port.count)
1360 		return -EBUSY;
1361 
1362 	DBGINFO(("%s hdlcdev_attach\n", info->device_name));
1363 
1364 	switch (encoding)
1365 	{
1366 	case ENCODING_NRZ:        new_encoding = HDLC_ENCODING_NRZ; break;
1367 	case ENCODING_NRZI:       new_encoding = HDLC_ENCODING_NRZI_SPACE; break;
1368 	case ENCODING_FM_MARK:    new_encoding = HDLC_ENCODING_BIPHASE_MARK; break;
1369 	case ENCODING_FM_SPACE:   new_encoding = HDLC_ENCODING_BIPHASE_SPACE; break;
1370 	case ENCODING_MANCHESTER: new_encoding = HDLC_ENCODING_BIPHASE_LEVEL; break;
1371 	default: return -EINVAL;
1372 	}
1373 
1374 	switch (parity)
1375 	{
1376 	case PARITY_NONE:            new_crctype = HDLC_CRC_NONE; break;
1377 	case PARITY_CRC16_PR1_CCITT: new_crctype = HDLC_CRC_16_CCITT; break;
1378 	case PARITY_CRC32_PR1_CCITT: new_crctype = HDLC_CRC_32_CCITT; break;
1379 	default: return -EINVAL;
1380 	}
1381 
1382 	info->params.encoding = new_encoding;
1383 	info->params.crc_type = new_crctype;
1384 
1385 	/* if network interface up, reprogram hardware */
1386 	if (info->netcount)
1387 		program_hw(info);
1388 
1389 	return 0;
1390 }
1391 
1392 /**
1393  * hdlcdev_xmit - called by generic HDLC layer to send a frame
1394  * @skb: socket buffer containing HDLC frame
1395  * @dev: pointer to network device structure
1396  */
1397 static netdev_tx_t hdlcdev_xmit(struct sk_buff *skb,
1398 				      struct net_device *dev)
1399 {
1400 	struct slgt_info *info = dev_to_port(dev);
1401 	unsigned long flags;
1402 
1403 	DBGINFO(("%s hdlc_xmit\n", dev->name));
1404 
1405 	if (!skb->len)
1406 		return NETDEV_TX_OK;
1407 
1408 	/* stop sending until this frame completes */
1409 	netif_stop_queue(dev);
1410 
1411 	/* update network statistics */
1412 	dev->stats.tx_packets++;
1413 	dev->stats.tx_bytes += skb->len;
1414 
1415 	/* save start time for transmit timeout detection */
1416 	netif_trans_update(dev);
1417 
1418 	spin_lock_irqsave(&info->lock, flags);
1419 	tx_load(info, skb->data, skb->len);
1420 	spin_unlock_irqrestore(&info->lock, flags);
1421 
1422 	/* done with socket buffer, so free it */
1423 	dev_kfree_skb(skb);
1424 
1425 	return NETDEV_TX_OK;
1426 }
1427 
1428 /**
1429  * hdlcdev_open - called by network layer when interface enabled
1430  * @dev: pointer to network device structure
1431  *
1432  * Claim resources and initialize hardware.
1433  *
1434  * Return: 0 if success, otherwise error code
1435  */
1436 static int hdlcdev_open(struct net_device *dev)
1437 {
1438 	struct slgt_info *info = dev_to_port(dev);
1439 	int rc;
1440 	unsigned long flags;
1441 
1442 	if (!try_module_get(THIS_MODULE))
1443 		return -EBUSY;
1444 
1445 	DBGINFO(("%s hdlcdev_open\n", dev->name));
1446 
1447 	/* generic HDLC layer open processing */
1448 	rc = hdlc_open(dev);
1449 	if (rc)
1450 		return rc;
1451 
1452 	/* arbitrate between network and tty opens */
1453 	spin_lock_irqsave(&info->netlock, flags);
1454 	if (info->port.count != 0 || info->netcount != 0) {
1455 		DBGINFO(("%s hdlc_open busy\n", dev->name));
1456 		spin_unlock_irqrestore(&info->netlock, flags);
1457 		return -EBUSY;
1458 	}
1459 	info->netcount=1;
1460 	spin_unlock_irqrestore(&info->netlock, flags);
1461 
1462 	/* claim resources and init adapter */
1463 	if ((rc = startup(info)) != 0) {
1464 		spin_lock_irqsave(&info->netlock, flags);
1465 		info->netcount=0;
1466 		spin_unlock_irqrestore(&info->netlock, flags);
1467 		return rc;
1468 	}
1469 
1470 	/* assert RTS and DTR, apply hardware settings */
1471 	info->signals |= SerialSignal_RTS | SerialSignal_DTR;
1472 	program_hw(info);
1473 
1474 	/* enable network layer transmit */
1475 	netif_trans_update(dev);
1476 	netif_start_queue(dev);
1477 
1478 	/* inform generic HDLC layer of current DCD status */
1479 	spin_lock_irqsave(&info->lock, flags);
1480 	get_signals(info);
1481 	spin_unlock_irqrestore(&info->lock, flags);
1482 	if (info->signals & SerialSignal_DCD)
1483 		netif_carrier_on(dev);
1484 	else
1485 		netif_carrier_off(dev);
1486 	return 0;
1487 }
1488 
1489 /**
1490  * hdlcdev_close - called by network layer when interface is disabled
1491  * @dev:  pointer to network device structure
1492  *
1493  * Shutdown hardware and release resources.
1494  *
1495  * Return: 0 if success, otherwise error code
1496  */
1497 static int hdlcdev_close(struct net_device *dev)
1498 {
1499 	struct slgt_info *info = dev_to_port(dev);
1500 	unsigned long flags;
1501 
1502 	DBGINFO(("%s hdlcdev_close\n", dev->name));
1503 
1504 	netif_stop_queue(dev);
1505 
1506 	/* shutdown adapter and release resources */
1507 	shutdown(info);
1508 
1509 	hdlc_close(dev);
1510 
1511 	spin_lock_irqsave(&info->netlock, flags);
1512 	info->netcount=0;
1513 	spin_unlock_irqrestore(&info->netlock, flags);
1514 
1515 	module_put(THIS_MODULE);
1516 	return 0;
1517 }
1518 
1519 /**
1520  * hdlcdev_ioctl - called by network layer to process IOCTL call to network device
1521  * @dev: pointer to network device structure
1522  * @ifr: pointer to network interface request structure
1523  * @cmd: IOCTL command code
1524  *
1525  * Return: 0 if success, otherwise error code
1526  */
1527 static int hdlcdev_ioctl(struct net_device *dev, struct if_settings *ifs)
1528 {
1529 	const size_t size = sizeof(sync_serial_settings);
1530 	sync_serial_settings new_line;
1531 	sync_serial_settings __user *line = ifs->ifs_ifsu.sync;
1532 	struct slgt_info *info = dev_to_port(dev);
1533 	unsigned int flags;
1534 
1535 	DBGINFO(("%s hdlcdev_ioctl\n", dev->name));
1536 
1537 	/* return error if TTY interface open */
1538 	if (info->port.count)
1539 		return -EBUSY;
1540 
1541 	memset(&new_line, 0, sizeof(new_line));
1542 
1543 	switch (ifs->type) {
1544 	case IF_GET_IFACE: /* return current sync_serial_settings */
1545 
1546 		ifs->type = IF_IFACE_SYNC_SERIAL;
1547 		if (ifs->size < size) {
1548 			ifs->size = size; /* data size wanted */
1549 			return -ENOBUFS;
1550 		}
1551 
1552 		flags = info->params.flags & (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
1553 					      HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
1554 					      HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
1555 					      HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN);
1556 
1557 		switch (flags){
1558 		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_TXCPIN): new_line.clock_type = CLOCK_EXT; break;
1559 		case (HDLC_FLAG_RXC_BRG    | HDLC_FLAG_TXC_BRG):    new_line.clock_type = CLOCK_INT; break;
1560 		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_BRG):    new_line.clock_type = CLOCK_TXINT; break;
1561 		case (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_RXCPIN): new_line.clock_type = CLOCK_TXFROMRX; break;
1562 		default: new_line.clock_type = CLOCK_DEFAULT;
1563 		}
1564 
1565 		new_line.clock_rate = info->params.clock_speed;
1566 		new_line.loopback   = info->params.loopback ? 1:0;
1567 
1568 		if (copy_to_user(line, &new_line, size))
1569 			return -EFAULT;
1570 		return 0;
1571 
1572 	case IF_IFACE_SYNC_SERIAL: /* set sync_serial_settings */
1573 
1574 		if(!capable(CAP_NET_ADMIN))
1575 			return -EPERM;
1576 		if (copy_from_user(&new_line, line, size))
1577 			return -EFAULT;
1578 
1579 		switch (new_line.clock_type)
1580 		{
1581 		case CLOCK_EXT:      flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_TXCPIN; break;
1582 		case CLOCK_TXFROMRX: flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_RXCPIN; break;
1583 		case CLOCK_INT:      flags = HDLC_FLAG_RXC_BRG    | HDLC_FLAG_TXC_BRG;    break;
1584 		case CLOCK_TXINT:    flags = HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_TXC_BRG;    break;
1585 		case CLOCK_DEFAULT:  flags = info->params.flags &
1586 					     (HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
1587 					      HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
1588 					      HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
1589 					      HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN); break;
1590 		default: return -EINVAL;
1591 		}
1592 
1593 		if (new_line.loopback != 0 && new_line.loopback != 1)
1594 			return -EINVAL;
1595 
1596 		info->params.flags &= ~(HDLC_FLAG_RXC_RXCPIN | HDLC_FLAG_RXC_DPLL |
1597 					HDLC_FLAG_RXC_BRG    | HDLC_FLAG_RXC_TXCPIN |
1598 					HDLC_FLAG_TXC_TXCPIN | HDLC_FLAG_TXC_DPLL |
1599 					HDLC_FLAG_TXC_BRG    | HDLC_FLAG_TXC_RXCPIN);
1600 		info->params.flags |= flags;
1601 
1602 		info->params.loopback = new_line.loopback;
1603 
1604 		if (flags & (HDLC_FLAG_RXC_BRG | HDLC_FLAG_TXC_BRG))
1605 			info->params.clock_speed = new_line.clock_rate;
1606 		else
1607 			info->params.clock_speed = 0;
1608 
1609 		/* if network interface up, reprogram hardware */
1610 		if (info->netcount)
1611 			program_hw(info);
1612 		return 0;
1613 
1614 	default:
1615 		return hdlc_ioctl(dev, ifs);
1616 	}
1617 }
1618 
1619 /**
1620  * hdlcdev_tx_timeout - called by network layer when transmit timeout is detected
1621  * @dev: pointer to network device structure
1622  * @txqueue: unused
1623  */
1624 static void hdlcdev_tx_timeout(struct net_device *dev, unsigned int txqueue)
1625 {
1626 	struct slgt_info *info = dev_to_port(dev);
1627 	unsigned long flags;
1628 
1629 	DBGINFO(("%s hdlcdev_tx_timeout\n", dev->name));
1630 
1631 	dev->stats.tx_errors++;
1632 	dev->stats.tx_aborted_errors++;
1633 
1634 	spin_lock_irqsave(&info->lock,flags);
1635 	tx_stop(info);
1636 	spin_unlock_irqrestore(&info->lock,flags);
1637 
1638 	netif_wake_queue(dev);
1639 }
1640 
1641 /**
1642  * hdlcdev_tx_done - called by device driver when transmit completes
1643  * @info: pointer to device instance information
1644  *
1645  * Reenable network layer transmit if stopped.
1646  */
1647 static void hdlcdev_tx_done(struct slgt_info *info)
1648 {
1649 	if (netif_queue_stopped(info->netdev))
1650 		netif_wake_queue(info->netdev);
1651 }
1652 
1653 /**
1654  * hdlcdev_rx - called by device driver when frame received
1655  * @info: pointer to device instance information
1656  * @buf:  pointer to buffer contianing frame data
1657  * @size: count of data bytes in buf
1658  *
1659  * Pass frame to network layer.
1660  */
1661 static void hdlcdev_rx(struct slgt_info *info, char *buf, int size)
1662 {
1663 	struct sk_buff *skb = dev_alloc_skb(size);
1664 	struct net_device *dev = info->netdev;
1665 
1666 	DBGINFO(("%s hdlcdev_rx\n", dev->name));
1667 
1668 	if (skb == NULL) {
1669 		DBGERR(("%s: can't alloc skb, drop packet\n", dev->name));
1670 		dev->stats.rx_dropped++;
1671 		return;
1672 	}
1673 
1674 	skb_put_data(skb, buf, size);
1675 
1676 	skb->protocol = hdlc_type_trans(skb, dev);
1677 
1678 	dev->stats.rx_packets++;
1679 	dev->stats.rx_bytes += size;
1680 
1681 	netif_rx(skb);
1682 }
1683 
1684 static const struct net_device_ops hdlcdev_ops = {
1685 	.ndo_open       = hdlcdev_open,
1686 	.ndo_stop       = hdlcdev_close,
1687 	.ndo_start_xmit = hdlc_start_xmit,
1688 	.ndo_siocwandev = hdlcdev_ioctl,
1689 	.ndo_tx_timeout = hdlcdev_tx_timeout,
1690 };
1691 
1692 /**
1693  * hdlcdev_init - called by device driver when adding device instance
1694  * @info: pointer to device instance information
1695  *
1696  * Do generic HDLC initialization.
1697  *
1698  * Return: 0 if success, otherwise error code
1699  */
1700 static int hdlcdev_init(struct slgt_info *info)
1701 {
1702 	int rc;
1703 	struct net_device *dev;
1704 	hdlc_device *hdlc;
1705 
1706 	/* allocate and initialize network and HDLC layer objects */
1707 
1708 	dev = alloc_hdlcdev(info);
1709 	if (!dev) {
1710 		printk(KERN_ERR "%s hdlc device alloc failure\n", info->device_name);
1711 		return -ENOMEM;
1712 	}
1713 
1714 	/* for network layer reporting purposes only */
1715 	dev->mem_start = info->phys_reg_addr;
1716 	dev->mem_end   = info->phys_reg_addr + SLGT_REG_SIZE - 1;
1717 	dev->irq       = info->irq_level;
1718 
1719 	/* network layer callbacks and settings */
1720 	dev->netdev_ops	    = &hdlcdev_ops;
1721 	dev->watchdog_timeo = 10 * HZ;
1722 	dev->tx_queue_len   = 50;
1723 
1724 	/* generic HDLC layer callbacks and settings */
1725 	hdlc         = dev_to_hdlc(dev);
1726 	hdlc->attach = hdlcdev_attach;
1727 	hdlc->xmit   = hdlcdev_xmit;
1728 
1729 	/* register objects with HDLC layer */
1730 	rc = register_hdlc_device(dev);
1731 	if (rc) {
1732 		printk(KERN_WARNING "%s:unable to register hdlc device\n",__FILE__);
1733 		free_netdev(dev);
1734 		return rc;
1735 	}
1736 
1737 	info->netdev = dev;
1738 	return 0;
1739 }
1740 
1741 /**
1742  * hdlcdev_exit - called by device driver when removing device instance
1743  * @info: pointer to device instance information
1744  *
1745  * Do generic HDLC cleanup.
1746  */
1747 static void hdlcdev_exit(struct slgt_info *info)
1748 {
1749 	unregister_hdlc_device(info->netdev);
1750 	free_netdev(info->netdev);
1751 	info->netdev = NULL;
1752 }
1753 
1754 #endif /* ifdef CONFIG_HDLC */
1755 
1756 /*
1757  * get async data from rx DMA buffers
1758  */
1759 static void rx_async(struct slgt_info *info)
1760 {
1761  	struct mgsl_icount *icount = &info->icount;
1762 	unsigned int start, end;
1763 	unsigned char *p;
1764 	unsigned char status;
1765 	struct slgt_desc *bufs = info->rbufs;
1766 	int i, count;
1767 	int chars = 0;
1768 	int stat;
1769 	unsigned char ch;
1770 
1771 	start = end = info->rbuf_current;
1772 
1773 	while(desc_complete(bufs[end])) {
1774 		count = desc_count(bufs[end]) - info->rbuf_index;
1775 		p     = bufs[end].buf + info->rbuf_index;
1776 
1777 		DBGISR(("%s rx_async count=%d\n", info->device_name, count));
1778 		DBGDATA(info, p, count, "rx");
1779 
1780 		for(i=0 ; i < count; i+=2, p+=2) {
1781 			ch = *p;
1782 			icount->rx++;
1783 
1784 			stat = 0;
1785 
1786 			status = *(p + 1) & (BIT1 + BIT0);
1787 			if (status) {
1788 				if (status & BIT1)
1789 					icount->parity++;
1790 				else if (status & BIT0)
1791 					icount->frame++;
1792 				/* discard char if tty control flags say so */
1793 				if (status & info->ignore_status_mask)
1794 					continue;
1795 				if (status & BIT1)
1796 					stat = TTY_PARITY;
1797 				else if (status & BIT0)
1798 					stat = TTY_FRAME;
1799 			}
1800 			tty_insert_flip_char(&info->port, ch, stat);
1801 			chars++;
1802 		}
1803 
1804 		if (i < count) {
1805 			/* receive buffer not completed */
1806 			info->rbuf_index += i;
1807 			mod_timer(&info->rx_timer, jiffies + 1);
1808 			break;
1809 		}
1810 
1811 		info->rbuf_index = 0;
1812 		free_rbufs(info, end, end);
1813 
1814 		if (++end == info->rbuf_count)
1815 			end = 0;
1816 
1817 		/* if entire list searched then no frame available */
1818 		if (end == start)
1819 			break;
1820 	}
1821 
1822 	if (chars)
1823 		tty_flip_buffer_push(&info->port);
1824 }
1825 
1826 /*
1827  * return next bottom half action to perform
1828  */
1829 static int bh_action(struct slgt_info *info)
1830 {
1831 	unsigned long flags;
1832 	int rc;
1833 
1834 	spin_lock_irqsave(&info->lock,flags);
1835 
1836 	if (info->pending_bh & BH_RECEIVE) {
1837 		info->pending_bh &= ~BH_RECEIVE;
1838 		rc = BH_RECEIVE;
1839 	} else if (info->pending_bh & BH_TRANSMIT) {
1840 		info->pending_bh &= ~BH_TRANSMIT;
1841 		rc = BH_TRANSMIT;
1842 	} else if (info->pending_bh & BH_STATUS) {
1843 		info->pending_bh &= ~BH_STATUS;
1844 		rc = BH_STATUS;
1845 	} else {
1846 		/* Mark BH routine as complete */
1847 		info->bh_running = false;
1848 		info->bh_requested = false;
1849 		rc = 0;
1850 	}
1851 
1852 	spin_unlock_irqrestore(&info->lock,flags);
1853 
1854 	return rc;
1855 }
1856 
1857 /*
1858  * perform bottom half processing
1859  */
1860 static void bh_handler(struct work_struct *work)
1861 {
1862 	struct slgt_info *info = container_of(work, struct slgt_info, task);
1863 	int action;
1864 
1865 	info->bh_running = true;
1866 
1867 	while((action = bh_action(info))) {
1868 		switch (action) {
1869 		case BH_RECEIVE:
1870 			DBGBH(("%s bh receive\n", info->device_name));
1871 			switch(info->params.mode) {
1872 			case MGSL_MODE_ASYNC:
1873 				rx_async(info);
1874 				break;
1875 			case MGSL_MODE_HDLC:
1876 				while(rx_get_frame(info));
1877 				break;
1878 			case MGSL_MODE_RAW:
1879 			case MGSL_MODE_MONOSYNC:
1880 			case MGSL_MODE_BISYNC:
1881 			case MGSL_MODE_XSYNC:
1882 				while(rx_get_buf(info));
1883 				break;
1884 			}
1885 			/* restart receiver if rx DMA buffers exhausted */
1886 			if (info->rx_restart)
1887 				rx_start(info);
1888 			break;
1889 		case BH_TRANSMIT:
1890 			bh_transmit(info);
1891 			break;
1892 		case BH_STATUS:
1893 			DBGBH(("%s bh status\n", info->device_name));
1894 			info->ri_chkcount = 0;
1895 			info->dsr_chkcount = 0;
1896 			info->dcd_chkcount = 0;
1897 			info->cts_chkcount = 0;
1898 			break;
1899 		default:
1900 			DBGBH(("%s unknown action\n", info->device_name));
1901 			break;
1902 		}
1903 	}
1904 	DBGBH(("%s bh_handler exit\n", info->device_name));
1905 }
1906 
1907 static void bh_transmit(struct slgt_info *info)
1908 {
1909 	struct tty_struct *tty = info->port.tty;
1910 
1911 	DBGBH(("%s bh_transmit\n", info->device_name));
1912 	if (tty)
1913 		tty_wakeup(tty);
1914 }
1915 
1916 static void dsr_change(struct slgt_info *info, unsigned short status)
1917 {
1918 	if (status & BIT3) {
1919 		info->signals |= SerialSignal_DSR;
1920 		info->input_signal_events.dsr_up++;
1921 	} else {
1922 		info->signals &= ~SerialSignal_DSR;
1923 		info->input_signal_events.dsr_down++;
1924 	}
1925 	DBGISR(("dsr_change %s signals=%04X\n", info->device_name, info->signals));
1926 	if ((info->dsr_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
1927 		slgt_irq_off(info, IRQ_DSR);
1928 		return;
1929 	}
1930 	info->icount.dsr++;
1931 	wake_up_interruptible(&info->status_event_wait_q);
1932 	wake_up_interruptible(&info->event_wait_q);
1933 	info->pending_bh |= BH_STATUS;
1934 }
1935 
1936 static void cts_change(struct slgt_info *info, unsigned short status)
1937 {
1938 	if (status & BIT2) {
1939 		info->signals |= SerialSignal_CTS;
1940 		info->input_signal_events.cts_up++;
1941 	} else {
1942 		info->signals &= ~SerialSignal_CTS;
1943 		info->input_signal_events.cts_down++;
1944 	}
1945 	DBGISR(("cts_change %s signals=%04X\n", info->device_name, info->signals));
1946 	if ((info->cts_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
1947 		slgt_irq_off(info, IRQ_CTS);
1948 		return;
1949 	}
1950 	info->icount.cts++;
1951 	wake_up_interruptible(&info->status_event_wait_q);
1952 	wake_up_interruptible(&info->event_wait_q);
1953 	info->pending_bh |= BH_STATUS;
1954 
1955 	if (tty_port_cts_enabled(&info->port)) {
1956 		if (info->port.tty) {
1957 			if (info->port.tty->hw_stopped) {
1958 				if (info->signals & SerialSignal_CTS) {
1959 		 			info->port.tty->hw_stopped = 0;
1960 					info->pending_bh |= BH_TRANSMIT;
1961 					return;
1962 				}
1963 			} else {
1964 				if (!(info->signals & SerialSignal_CTS))
1965 		 			info->port.tty->hw_stopped = 1;
1966 			}
1967 		}
1968 	}
1969 }
1970 
1971 static void dcd_change(struct slgt_info *info, unsigned short status)
1972 {
1973 	if (status & BIT1) {
1974 		info->signals |= SerialSignal_DCD;
1975 		info->input_signal_events.dcd_up++;
1976 	} else {
1977 		info->signals &= ~SerialSignal_DCD;
1978 		info->input_signal_events.dcd_down++;
1979 	}
1980 	DBGISR(("dcd_change %s signals=%04X\n", info->device_name, info->signals));
1981 	if ((info->dcd_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
1982 		slgt_irq_off(info, IRQ_DCD);
1983 		return;
1984 	}
1985 	info->icount.dcd++;
1986 #if SYNCLINK_GENERIC_HDLC
1987 	if (info->netcount) {
1988 		if (info->signals & SerialSignal_DCD)
1989 			netif_carrier_on(info->netdev);
1990 		else
1991 			netif_carrier_off(info->netdev);
1992 	}
1993 #endif
1994 	wake_up_interruptible(&info->status_event_wait_q);
1995 	wake_up_interruptible(&info->event_wait_q);
1996 	info->pending_bh |= BH_STATUS;
1997 
1998 	if (tty_port_check_carrier(&info->port)) {
1999 		if (info->signals & SerialSignal_DCD)
2000 			wake_up_interruptible(&info->port.open_wait);
2001 		else {
2002 			if (info->port.tty)
2003 				tty_hangup(info->port.tty);
2004 		}
2005 	}
2006 }
2007 
2008 static void ri_change(struct slgt_info *info, unsigned short status)
2009 {
2010 	if (status & BIT0) {
2011 		info->signals |= SerialSignal_RI;
2012 		info->input_signal_events.ri_up++;
2013 	} else {
2014 		info->signals &= ~SerialSignal_RI;
2015 		info->input_signal_events.ri_down++;
2016 	}
2017 	DBGISR(("ri_change %s signals=%04X\n", info->device_name, info->signals));
2018 	if ((info->ri_chkcount)++ == IO_PIN_SHUTDOWN_LIMIT) {
2019 		slgt_irq_off(info, IRQ_RI);
2020 		return;
2021 	}
2022 	info->icount.rng++;
2023 	wake_up_interruptible(&info->status_event_wait_q);
2024 	wake_up_interruptible(&info->event_wait_q);
2025 	info->pending_bh |= BH_STATUS;
2026 }
2027 
2028 static void isr_rxdata(struct slgt_info *info)
2029 {
2030 	unsigned int count = info->rbuf_fill_count;
2031 	unsigned int i = info->rbuf_fill_index;
2032 	unsigned short reg;
2033 
2034 	while (rd_reg16(info, SSR) & IRQ_RXDATA) {
2035 		reg = rd_reg16(info, RDR);
2036 		DBGISR(("isr_rxdata %s RDR=%04X\n", info->device_name, reg));
2037 		if (desc_complete(info->rbufs[i])) {
2038 			/* all buffers full */
2039 			rx_stop(info);
2040 			info->rx_restart = true;
2041 			continue;
2042 		}
2043 		info->rbufs[i].buf[count++] = (unsigned char)reg;
2044 		/* async mode saves status byte to buffer for each data byte */
2045 		if (info->params.mode == MGSL_MODE_ASYNC)
2046 			info->rbufs[i].buf[count++] = (unsigned char)(reg >> 8);
2047 		if (count == info->rbuf_fill_level || (reg & BIT10)) {
2048 			/* buffer full or end of frame */
2049 			set_desc_count(info->rbufs[i], count);
2050 			set_desc_status(info->rbufs[i], BIT15 | (reg >> 8));
2051 			info->rbuf_fill_count = count = 0;
2052 			if (++i == info->rbuf_count)
2053 				i = 0;
2054 			info->pending_bh |= BH_RECEIVE;
2055 		}
2056 	}
2057 
2058 	info->rbuf_fill_index = i;
2059 	info->rbuf_fill_count = count;
2060 }
2061 
2062 static void isr_serial(struct slgt_info *info)
2063 {
2064 	unsigned short status = rd_reg16(info, SSR);
2065 
2066 	DBGISR(("%s isr_serial status=%04X\n", info->device_name, status));
2067 
2068 	wr_reg16(info, SSR, status); /* clear pending */
2069 
2070 	info->irq_occurred = true;
2071 
2072 	if (info->params.mode == MGSL_MODE_ASYNC) {
2073 		if (status & IRQ_TXIDLE) {
2074 			if (info->tx_active)
2075 				isr_txeom(info, status);
2076 		}
2077 		if (info->rx_pio && (status & IRQ_RXDATA))
2078 			isr_rxdata(info);
2079 		if ((status & IRQ_RXBREAK) && (status & RXBREAK)) {
2080 			info->icount.brk++;
2081 			/* process break detection if tty control allows */
2082 			if (info->port.tty) {
2083 				if (!(status & info->ignore_status_mask)) {
2084 					if (info->read_status_mask & MASK_BREAK) {
2085 						tty_insert_flip_char(&info->port, 0, TTY_BREAK);
2086 						if (info->port.flags & ASYNC_SAK)
2087 							do_SAK(info->port.tty);
2088 					}
2089 				}
2090 			}
2091 		}
2092 	} else {
2093 		if (status & (IRQ_TXIDLE + IRQ_TXUNDER))
2094 			isr_txeom(info, status);
2095 		if (info->rx_pio && (status & IRQ_RXDATA))
2096 			isr_rxdata(info);
2097 		if (status & IRQ_RXIDLE) {
2098 			if (status & RXIDLE)
2099 				info->icount.rxidle++;
2100 			else
2101 				info->icount.exithunt++;
2102 			wake_up_interruptible(&info->event_wait_q);
2103 		}
2104 
2105 		if (status & IRQ_RXOVER)
2106 			rx_start(info);
2107 	}
2108 
2109 	if (status & IRQ_DSR)
2110 		dsr_change(info, status);
2111 	if (status & IRQ_CTS)
2112 		cts_change(info, status);
2113 	if (status & IRQ_DCD)
2114 		dcd_change(info, status);
2115 	if (status & IRQ_RI)
2116 		ri_change(info, status);
2117 }
2118 
2119 static void isr_rdma(struct slgt_info *info)
2120 {
2121 	unsigned int status = rd_reg32(info, RDCSR);
2122 
2123 	DBGISR(("%s isr_rdma status=%08x\n", info->device_name, status));
2124 
2125 	/* RDCSR (rx DMA control/status)
2126 	 *
2127 	 * 31..07  reserved
2128 	 * 06      save status byte to DMA buffer
2129 	 * 05      error
2130 	 * 04      eol (end of list)
2131 	 * 03      eob (end of buffer)
2132 	 * 02      IRQ enable
2133 	 * 01      reset
2134 	 * 00      enable
2135 	 */
2136 	wr_reg32(info, RDCSR, status);	/* clear pending */
2137 
2138 	if (status & (BIT5 + BIT4)) {
2139 		DBGISR(("%s isr_rdma rx_restart=1\n", info->device_name));
2140 		info->rx_restart = true;
2141 	}
2142 	info->pending_bh |= BH_RECEIVE;
2143 }
2144 
2145 static void isr_tdma(struct slgt_info *info)
2146 {
2147 	unsigned int status = rd_reg32(info, TDCSR);
2148 
2149 	DBGISR(("%s isr_tdma status=%08x\n", info->device_name, status));
2150 
2151 	/* TDCSR (tx DMA control/status)
2152 	 *
2153 	 * 31..06  reserved
2154 	 * 05      error
2155 	 * 04      eol (end of list)
2156 	 * 03      eob (end of buffer)
2157 	 * 02      IRQ enable
2158 	 * 01      reset
2159 	 * 00      enable
2160 	 */
2161 	wr_reg32(info, TDCSR, status);	/* clear pending */
2162 
2163 	if (status & (BIT5 + BIT4 + BIT3)) {
2164 		// another transmit buffer has completed
2165 		// run bottom half to get more send data from user
2166 		info->pending_bh |= BH_TRANSMIT;
2167 	}
2168 }
2169 
2170 /*
2171  * return true if there are unsent tx DMA buffers, otherwise false
2172  *
2173  * if there are unsent buffers then info->tbuf_start
2174  * is set to index of first unsent buffer
2175  */
2176 static bool unsent_tbufs(struct slgt_info *info)
2177 {
2178 	unsigned int i = info->tbuf_current;
2179 	bool rc = false;
2180 
2181 	/*
2182 	 * search backwards from last loaded buffer (precedes tbuf_current)
2183 	 * for first unsent buffer (desc_count > 0)
2184 	 */
2185 
2186 	do {
2187 		if (i)
2188 			i--;
2189 		else
2190 			i = info->tbuf_count - 1;
2191 		if (!desc_count(info->tbufs[i]))
2192 			break;
2193 		info->tbuf_start = i;
2194 		rc = true;
2195 	} while (i != info->tbuf_current);
2196 
2197 	return rc;
2198 }
2199 
2200 static void isr_txeom(struct slgt_info *info, unsigned short status)
2201 {
2202 	DBGISR(("%s txeom status=%04x\n", info->device_name, status));
2203 
2204 	slgt_irq_off(info, IRQ_TXDATA + IRQ_TXIDLE + IRQ_TXUNDER);
2205 	tdma_reset(info);
2206 	if (status & IRQ_TXUNDER) {
2207 		unsigned short val = rd_reg16(info, TCR);
2208 		wr_reg16(info, TCR, (unsigned short)(val | BIT2)); /* set reset bit */
2209 		wr_reg16(info, TCR, val); /* clear reset bit */
2210 	}
2211 
2212 	if (info->tx_active) {
2213 		if (info->params.mode != MGSL_MODE_ASYNC) {
2214 			if (status & IRQ_TXUNDER)
2215 				info->icount.txunder++;
2216 			else if (status & IRQ_TXIDLE)
2217 				info->icount.txok++;
2218 		}
2219 
2220 		if (unsent_tbufs(info)) {
2221 			tx_start(info);
2222 			update_tx_timer(info);
2223 			return;
2224 		}
2225 		info->tx_active = false;
2226 
2227 		del_timer(&info->tx_timer);
2228 
2229 		if (info->params.mode != MGSL_MODE_ASYNC && info->drop_rts_on_tx_done) {
2230 			info->signals &= ~SerialSignal_RTS;
2231 			info->drop_rts_on_tx_done = false;
2232 			set_signals(info);
2233 		}
2234 
2235 #if SYNCLINK_GENERIC_HDLC
2236 		if (info->netcount)
2237 			hdlcdev_tx_done(info);
2238 		else
2239 #endif
2240 		{
2241 			if (info->port.tty && (info->port.tty->flow.stopped || info->port.tty->hw_stopped)) {
2242 				tx_stop(info);
2243 				return;
2244 			}
2245 			info->pending_bh |= BH_TRANSMIT;
2246 		}
2247 	}
2248 }
2249 
2250 static void isr_gpio(struct slgt_info *info, unsigned int changed, unsigned int state)
2251 {
2252 	struct cond_wait *w, *prev;
2253 
2254 	/* wake processes waiting for specific transitions */
2255 	for (w = info->gpio_wait_q, prev = NULL ; w != NULL ; w = w->next) {
2256 		if (w->data & changed) {
2257 			w->data = state;
2258 			wake_up_interruptible(&w->q);
2259 			if (prev != NULL)
2260 				prev->next = w->next;
2261 			else
2262 				info->gpio_wait_q = w->next;
2263 		} else
2264 			prev = w;
2265 	}
2266 }
2267 
2268 /* interrupt service routine
2269  *
2270  * 	irq	interrupt number
2271  * 	dev_id	device ID supplied during interrupt registration
2272  */
2273 static irqreturn_t slgt_interrupt(int dummy, void *dev_id)
2274 {
2275 	struct slgt_info *info = dev_id;
2276 	unsigned int gsr;
2277 	unsigned int i;
2278 
2279 	DBGISR(("slgt_interrupt irq=%d entry\n", info->irq_level));
2280 
2281 	while((gsr = rd_reg32(info, GSR) & 0xffffff00)) {
2282 		DBGISR(("%s gsr=%08x\n", info->device_name, gsr));
2283 		info->irq_occurred = true;
2284 		for(i=0; i < info->port_count ; i++) {
2285 			if (info->port_array[i] == NULL)
2286 				continue;
2287 			spin_lock(&info->port_array[i]->lock);
2288 			if (gsr & (BIT8 << i))
2289 				isr_serial(info->port_array[i]);
2290 			if (gsr & (BIT16 << (i*2)))
2291 				isr_rdma(info->port_array[i]);
2292 			if (gsr & (BIT17 << (i*2)))
2293 				isr_tdma(info->port_array[i]);
2294 			spin_unlock(&info->port_array[i]->lock);
2295 		}
2296 	}
2297 
2298 	if (info->gpio_present) {
2299 		unsigned int state;
2300 		unsigned int changed;
2301 		spin_lock(&info->lock);
2302 		while ((changed = rd_reg32(info, IOSR)) != 0) {
2303 			DBGISR(("%s iosr=%08x\n", info->device_name, changed));
2304 			/* read latched state of GPIO signals */
2305 			state = rd_reg32(info, IOVR);
2306 			/* clear pending GPIO interrupt bits */
2307 			wr_reg32(info, IOSR, changed);
2308 			for (i=0 ; i < info->port_count ; i++) {
2309 				if (info->port_array[i] != NULL)
2310 					isr_gpio(info->port_array[i], changed, state);
2311 			}
2312 		}
2313 		spin_unlock(&info->lock);
2314 	}
2315 
2316 	for(i=0; i < info->port_count ; i++) {
2317 		struct slgt_info *port = info->port_array[i];
2318 		if (port == NULL)
2319 			continue;
2320 		spin_lock(&port->lock);
2321 		if ((port->port.count || port->netcount) &&
2322 		    port->pending_bh && !port->bh_running &&
2323 		    !port->bh_requested) {
2324 			DBGISR(("%s bh queued\n", port->device_name));
2325 			schedule_work(&port->task);
2326 			port->bh_requested = true;
2327 		}
2328 		spin_unlock(&port->lock);
2329 	}
2330 
2331 	DBGISR(("slgt_interrupt irq=%d exit\n", info->irq_level));
2332 	return IRQ_HANDLED;
2333 }
2334 
2335 static int startup(struct slgt_info *info)
2336 {
2337 	DBGINFO(("%s startup\n", info->device_name));
2338 
2339 	if (tty_port_initialized(&info->port))
2340 		return 0;
2341 
2342 	if (!info->tx_buf) {
2343 		info->tx_buf = kmalloc(info->max_frame_size, GFP_KERNEL);
2344 		if (!info->tx_buf) {
2345 			DBGERR(("%s can't allocate tx buffer\n", info->device_name));
2346 			return -ENOMEM;
2347 		}
2348 	}
2349 
2350 	info->pending_bh = 0;
2351 
2352 	memset(&info->icount, 0, sizeof(info->icount));
2353 
2354 	/* program hardware for current parameters */
2355 	change_params(info);
2356 
2357 	if (info->port.tty)
2358 		clear_bit(TTY_IO_ERROR, &info->port.tty->flags);
2359 
2360 	tty_port_set_initialized(&info->port, 1);
2361 
2362 	return 0;
2363 }
2364 
2365 /*
2366  *  called by close() and hangup() to shutdown hardware
2367  */
2368 static void shutdown(struct slgt_info *info)
2369 {
2370 	unsigned long flags;
2371 
2372 	if (!tty_port_initialized(&info->port))
2373 		return;
2374 
2375 	DBGINFO(("%s shutdown\n", info->device_name));
2376 
2377 	/* clear status wait queue because status changes */
2378 	/* can't happen after shutting down the hardware */
2379 	wake_up_interruptible(&info->status_event_wait_q);
2380 	wake_up_interruptible(&info->event_wait_q);
2381 
2382 	del_timer_sync(&info->tx_timer);
2383 	del_timer_sync(&info->rx_timer);
2384 
2385 	kfree(info->tx_buf);
2386 	info->tx_buf = NULL;
2387 
2388 	spin_lock_irqsave(&info->lock,flags);
2389 
2390 	tx_stop(info);
2391 	rx_stop(info);
2392 
2393 	slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);
2394 
2395  	if (!info->port.tty || info->port.tty->termios.c_cflag & HUPCL) {
2396 		info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
2397 		set_signals(info);
2398 	}
2399 
2400 	flush_cond_wait(&info->gpio_wait_q);
2401 
2402 	spin_unlock_irqrestore(&info->lock,flags);
2403 
2404 	if (info->port.tty)
2405 		set_bit(TTY_IO_ERROR, &info->port.tty->flags);
2406 
2407 	tty_port_set_initialized(&info->port, 0);
2408 }
2409 
2410 static void program_hw(struct slgt_info *info)
2411 {
2412 	unsigned long flags;
2413 
2414 	spin_lock_irqsave(&info->lock,flags);
2415 
2416 	rx_stop(info);
2417 	tx_stop(info);
2418 
2419 	if (info->params.mode != MGSL_MODE_ASYNC ||
2420 	    info->netcount)
2421 		sync_mode(info);
2422 	else
2423 		async_mode(info);
2424 
2425 	set_signals(info);
2426 
2427 	info->dcd_chkcount = 0;
2428 	info->cts_chkcount = 0;
2429 	info->ri_chkcount = 0;
2430 	info->dsr_chkcount = 0;
2431 
2432 	slgt_irq_on(info, IRQ_DCD | IRQ_CTS | IRQ_DSR | IRQ_RI);
2433 	get_signals(info);
2434 
2435 	if (info->netcount ||
2436 	    (info->port.tty && info->port.tty->termios.c_cflag & CREAD))
2437 		rx_start(info);
2438 
2439 	spin_unlock_irqrestore(&info->lock,flags);
2440 }
2441 
2442 /*
2443  * reconfigure adapter based on new parameters
2444  */
2445 static void change_params(struct slgt_info *info)
2446 {
2447 	unsigned cflag;
2448 	int bits_per_char;
2449 
2450 	if (!info->port.tty)
2451 		return;
2452 	DBGINFO(("%s change_params\n", info->device_name));
2453 
2454 	cflag = info->port.tty->termios.c_cflag;
2455 
2456 	/* if B0 rate (hangup) specified then negate RTS and DTR */
2457 	/* otherwise assert RTS and DTR */
2458  	if (cflag & CBAUD)
2459 		info->signals |= SerialSignal_RTS | SerialSignal_DTR;
2460 	else
2461 		info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
2462 
2463 	/* byte size and parity */
2464 
2465 	info->params.data_bits = tty_get_char_size(cflag);
2466 	info->params.stop_bits = (cflag & CSTOPB) ? 2 : 1;
2467 
2468 	if (cflag & PARENB)
2469 		info->params.parity = (cflag & PARODD) ? ASYNC_PARITY_ODD : ASYNC_PARITY_EVEN;
2470 	else
2471 		info->params.parity = ASYNC_PARITY_NONE;
2472 
2473 	/* calculate number of jiffies to transmit a full
2474 	 * FIFO (32 bytes) at specified data rate
2475 	 */
2476 	bits_per_char = info->params.data_bits +
2477 			info->params.stop_bits + 1;
2478 
2479 	info->params.data_rate = tty_get_baud_rate(info->port.tty);
2480 
2481 	if (info->params.data_rate) {
2482 		info->timeout = (32*HZ*bits_per_char) /
2483 				info->params.data_rate;
2484 	}
2485 	info->timeout += HZ/50;		/* Add .02 seconds of slop */
2486 
2487 	tty_port_set_cts_flow(&info->port, cflag & CRTSCTS);
2488 	tty_port_set_check_carrier(&info->port, ~cflag & CLOCAL);
2489 
2490 	/* process tty input control flags */
2491 
2492 	info->read_status_mask = IRQ_RXOVER;
2493 	if (I_INPCK(info->port.tty))
2494 		info->read_status_mask |= MASK_PARITY | MASK_FRAMING;
2495 	if (I_BRKINT(info->port.tty) || I_PARMRK(info->port.tty))
2496 		info->read_status_mask |= MASK_BREAK;
2497 	if (I_IGNPAR(info->port.tty))
2498 		info->ignore_status_mask |= MASK_PARITY | MASK_FRAMING;
2499 	if (I_IGNBRK(info->port.tty)) {
2500 		info->ignore_status_mask |= MASK_BREAK;
2501 		/* If ignoring parity and break indicators, ignore
2502 		 * overruns too.  (For real raw support).
2503 		 */
2504 		if (I_IGNPAR(info->port.tty))
2505 			info->ignore_status_mask |= MASK_OVERRUN;
2506 	}
2507 
2508 	program_hw(info);
2509 }
2510 
2511 static int get_stats(struct slgt_info *info, struct mgsl_icount __user *user_icount)
2512 {
2513 	DBGINFO(("%s get_stats\n",  info->device_name));
2514 	if (!user_icount) {
2515 		memset(&info->icount, 0, sizeof(info->icount));
2516 	} else {
2517 		if (copy_to_user(user_icount, &info->icount, sizeof(struct mgsl_icount)))
2518 			return -EFAULT;
2519 	}
2520 	return 0;
2521 }
2522 
2523 static int get_params(struct slgt_info *info, MGSL_PARAMS __user *user_params)
2524 {
2525 	DBGINFO(("%s get_params\n", info->device_name));
2526 	if (copy_to_user(user_params, &info->params, sizeof(MGSL_PARAMS)))
2527 		return -EFAULT;
2528 	return 0;
2529 }
2530 
2531 static int set_params(struct slgt_info *info, MGSL_PARAMS __user *new_params)
2532 {
2533  	unsigned long flags;
2534 	MGSL_PARAMS tmp_params;
2535 
2536 	DBGINFO(("%s set_params\n", info->device_name));
2537 	if (copy_from_user(&tmp_params, new_params, sizeof(MGSL_PARAMS)))
2538 		return -EFAULT;
2539 
2540 	spin_lock_irqsave(&info->lock, flags);
2541 	if (tmp_params.mode == MGSL_MODE_BASE_CLOCK)
2542 		info->base_clock = tmp_params.clock_speed;
2543 	else
2544 		memcpy(&info->params, &tmp_params, sizeof(MGSL_PARAMS));
2545 	spin_unlock_irqrestore(&info->lock, flags);
2546 
2547 	program_hw(info);
2548 
2549 	return 0;
2550 }
2551 
2552 static int get_txidle(struct slgt_info *info, int __user *idle_mode)
2553 {
2554 	DBGINFO(("%s get_txidle=%d\n", info->device_name, info->idle_mode));
2555 	if (put_user(info->idle_mode, idle_mode))
2556 		return -EFAULT;
2557 	return 0;
2558 }
2559 
2560 static int set_txidle(struct slgt_info *info, int idle_mode)
2561 {
2562  	unsigned long flags;
2563 	DBGINFO(("%s set_txidle(%d)\n", info->device_name, idle_mode));
2564 	spin_lock_irqsave(&info->lock,flags);
2565 	info->idle_mode = idle_mode;
2566 	if (info->params.mode != MGSL_MODE_ASYNC)
2567 		tx_set_idle(info);
2568 	spin_unlock_irqrestore(&info->lock,flags);
2569 	return 0;
2570 }
2571 
2572 static int tx_enable(struct slgt_info *info, int enable)
2573 {
2574  	unsigned long flags;
2575 	DBGINFO(("%s tx_enable(%d)\n", info->device_name, enable));
2576 	spin_lock_irqsave(&info->lock,flags);
2577 	if (enable) {
2578 		if (!info->tx_enabled)
2579 			tx_start(info);
2580 	} else {
2581 		if (info->tx_enabled)
2582 			tx_stop(info);
2583 	}
2584 	spin_unlock_irqrestore(&info->lock,flags);
2585 	return 0;
2586 }
2587 
2588 /*
2589  * abort transmit HDLC frame
2590  */
2591 static int tx_abort(struct slgt_info *info)
2592 {
2593  	unsigned long flags;
2594 	DBGINFO(("%s tx_abort\n", info->device_name));
2595 	spin_lock_irqsave(&info->lock,flags);
2596 	tdma_reset(info);
2597 	spin_unlock_irqrestore(&info->lock,flags);
2598 	return 0;
2599 }
2600 
2601 static int rx_enable(struct slgt_info *info, int enable)
2602 {
2603  	unsigned long flags;
2604 	unsigned int rbuf_fill_level;
2605 	DBGINFO(("%s rx_enable(%08x)\n", info->device_name, enable));
2606 	spin_lock_irqsave(&info->lock,flags);
2607 	/*
2608 	 * enable[31..16] = receive DMA buffer fill level
2609 	 * 0 = noop (leave fill level unchanged)
2610 	 * fill level must be multiple of 4 and <= buffer size
2611 	 */
2612 	rbuf_fill_level = ((unsigned int)enable) >> 16;
2613 	if (rbuf_fill_level) {
2614 		if ((rbuf_fill_level > DMABUFSIZE) || (rbuf_fill_level % 4)) {
2615 			spin_unlock_irqrestore(&info->lock, flags);
2616 			return -EINVAL;
2617 		}
2618 		info->rbuf_fill_level = rbuf_fill_level;
2619 		if (rbuf_fill_level < 128)
2620 			info->rx_pio = 1; /* PIO mode */
2621 		else
2622 			info->rx_pio = 0; /* DMA mode */
2623 		rx_stop(info); /* restart receiver to use new fill level */
2624 	}
2625 
2626 	/*
2627 	 * enable[1..0] = receiver enable command
2628 	 * 0 = disable
2629 	 * 1 = enable
2630 	 * 2 = enable or force hunt mode if already enabled
2631 	 */
2632 	enable &= 3;
2633 	if (enable) {
2634 		if (!info->rx_enabled)
2635 			rx_start(info);
2636 		else if (enable == 2) {
2637 			/* force hunt mode (write 1 to RCR[3]) */
2638 			wr_reg16(info, RCR, rd_reg16(info, RCR) | BIT3);
2639 		}
2640 	} else {
2641 		if (info->rx_enabled)
2642 			rx_stop(info);
2643 	}
2644 	spin_unlock_irqrestore(&info->lock,flags);
2645 	return 0;
2646 }
2647 
2648 /*
2649  *  wait for specified event to occur
2650  */
2651 static int wait_mgsl_event(struct slgt_info *info, int __user *mask_ptr)
2652 {
2653  	unsigned long flags;
2654 	int s;
2655 	int rc=0;
2656 	struct mgsl_icount cprev, cnow;
2657 	int events;
2658 	int mask;
2659 	struct	_input_signal_events oldsigs, newsigs;
2660 	DECLARE_WAITQUEUE(wait, current);
2661 
2662 	if (get_user(mask, mask_ptr))
2663 		return -EFAULT;
2664 
2665 	DBGINFO(("%s wait_mgsl_event(%d)\n", info->device_name, mask));
2666 
2667 	spin_lock_irqsave(&info->lock,flags);
2668 
2669 	/* return immediately if state matches requested events */
2670 	get_signals(info);
2671 	s = info->signals;
2672 
2673 	events = mask &
2674 		( ((s & SerialSignal_DSR) ? MgslEvent_DsrActive:MgslEvent_DsrInactive) +
2675  		  ((s & SerialSignal_DCD) ? MgslEvent_DcdActive:MgslEvent_DcdInactive) +
2676 		  ((s & SerialSignal_CTS) ? MgslEvent_CtsActive:MgslEvent_CtsInactive) +
2677 		  ((s & SerialSignal_RI)  ? MgslEvent_RiActive :MgslEvent_RiInactive) );
2678 	if (events) {
2679 		spin_unlock_irqrestore(&info->lock,flags);
2680 		goto exit;
2681 	}
2682 
2683 	/* save current irq counts */
2684 	cprev = info->icount;
2685 	oldsigs = info->input_signal_events;
2686 
2687 	/* enable hunt and idle irqs if needed */
2688 	if (mask & (MgslEvent_ExitHuntMode+MgslEvent_IdleReceived)) {
2689 		unsigned short val = rd_reg16(info, SCR);
2690 		if (!(val & IRQ_RXIDLE))
2691 			wr_reg16(info, SCR, (unsigned short)(val | IRQ_RXIDLE));
2692 	}
2693 
2694 	set_current_state(TASK_INTERRUPTIBLE);
2695 	add_wait_queue(&info->event_wait_q, &wait);
2696 
2697 	spin_unlock_irqrestore(&info->lock,flags);
2698 
2699 	for(;;) {
2700 		schedule();
2701 		if (signal_pending(current)) {
2702 			rc = -ERESTARTSYS;
2703 			break;
2704 		}
2705 
2706 		/* get current irq counts */
2707 		spin_lock_irqsave(&info->lock,flags);
2708 		cnow = info->icount;
2709 		newsigs = info->input_signal_events;
2710 		set_current_state(TASK_INTERRUPTIBLE);
2711 		spin_unlock_irqrestore(&info->lock,flags);
2712 
2713 		/* if no change, wait aborted for some reason */
2714 		if (newsigs.dsr_up   == oldsigs.dsr_up   &&
2715 		    newsigs.dsr_down == oldsigs.dsr_down &&
2716 		    newsigs.dcd_up   == oldsigs.dcd_up   &&
2717 		    newsigs.dcd_down == oldsigs.dcd_down &&
2718 		    newsigs.cts_up   == oldsigs.cts_up   &&
2719 		    newsigs.cts_down == oldsigs.cts_down &&
2720 		    newsigs.ri_up    == oldsigs.ri_up    &&
2721 		    newsigs.ri_down  == oldsigs.ri_down  &&
2722 		    cnow.exithunt    == cprev.exithunt   &&
2723 		    cnow.rxidle      == cprev.rxidle) {
2724 			rc = -EIO;
2725 			break;
2726 		}
2727 
2728 		events = mask &
2729 			( (newsigs.dsr_up   != oldsigs.dsr_up   ? MgslEvent_DsrActive:0)   +
2730 			  (newsigs.dsr_down != oldsigs.dsr_down ? MgslEvent_DsrInactive:0) +
2731 			  (newsigs.dcd_up   != oldsigs.dcd_up   ? MgslEvent_DcdActive:0)   +
2732 			  (newsigs.dcd_down != oldsigs.dcd_down ? MgslEvent_DcdInactive:0) +
2733 			  (newsigs.cts_up   != oldsigs.cts_up   ? MgslEvent_CtsActive:0)   +
2734 			  (newsigs.cts_down != oldsigs.cts_down ? MgslEvent_CtsInactive:0) +
2735 			  (newsigs.ri_up    != oldsigs.ri_up    ? MgslEvent_RiActive:0)    +
2736 			  (newsigs.ri_down  != oldsigs.ri_down  ? MgslEvent_RiInactive:0)  +
2737 			  (cnow.exithunt    != cprev.exithunt   ? MgslEvent_ExitHuntMode:0) +
2738 			  (cnow.rxidle      != cprev.rxidle     ? MgslEvent_IdleReceived:0) );
2739 		if (events)
2740 			break;
2741 
2742 		cprev = cnow;
2743 		oldsigs = newsigs;
2744 	}
2745 
2746 	remove_wait_queue(&info->event_wait_q, &wait);
2747 	set_current_state(TASK_RUNNING);
2748 
2749 
2750 	if (mask & (MgslEvent_ExitHuntMode + MgslEvent_IdleReceived)) {
2751 		spin_lock_irqsave(&info->lock,flags);
2752 		if (!waitqueue_active(&info->event_wait_q)) {
2753 			/* disable enable exit hunt mode/idle rcvd IRQs */
2754 			wr_reg16(info, SCR,
2755 				(unsigned short)(rd_reg16(info, SCR) & ~IRQ_RXIDLE));
2756 		}
2757 		spin_unlock_irqrestore(&info->lock,flags);
2758 	}
2759 exit:
2760 	if (rc == 0)
2761 		rc = put_user(events, mask_ptr);
2762 	return rc;
2763 }
2764 
2765 static int get_interface(struct slgt_info *info, int __user *if_mode)
2766 {
2767 	DBGINFO(("%s get_interface=%x\n", info->device_name, info->if_mode));
2768 	if (put_user(info->if_mode, if_mode))
2769 		return -EFAULT;
2770 	return 0;
2771 }
2772 
2773 static int set_interface(struct slgt_info *info, int if_mode)
2774 {
2775  	unsigned long flags;
2776 	unsigned short val;
2777 
2778 	DBGINFO(("%s set_interface=%x)\n", info->device_name, if_mode));
2779 	spin_lock_irqsave(&info->lock,flags);
2780 	info->if_mode = if_mode;
2781 
2782 	msc_set_vcr(info);
2783 
2784 	/* TCR (tx control) 07  1=RTS driver control */
2785 	val = rd_reg16(info, TCR);
2786 	if (info->if_mode & MGSL_INTERFACE_RTS_EN)
2787 		val |= BIT7;
2788 	else
2789 		val &= ~BIT7;
2790 	wr_reg16(info, TCR, val);
2791 
2792 	spin_unlock_irqrestore(&info->lock,flags);
2793 	return 0;
2794 }
2795 
2796 static int get_xsync(struct slgt_info *info, int __user *xsync)
2797 {
2798 	DBGINFO(("%s get_xsync=%x\n", info->device_name, info->xsync));
2799 	if (put_user(info->xsync, xsync))
2800 		return -EFAULT;
2801 	return 0;
2802 }
2803 
2804 /*
2805  * set extended sync pattern (1 to 4 bytes) for extended sync mode
2806  *
2807  * sync pattern is contained in least significant bytes of value
2808  * most significant byte of sync pattern is oldest (1st sent/detected)
2809  */
2810 static int set_xsync(struct slgt_info *info, int xsync)
2811 {
2812 	unsigned long flags;
2813 
2814 	DBGINFO(("%s set_xsync=%x)\n", info->device_name, xsync));
2815 	spin_lock_irqsave(&info->lock, flags);
2816 	info->xsync = xsync;
2817 	wr_reg32(info, XSR, xsync);
2818 	spin_unlock_irqrestore(&info->lock, flags);
2819 	return 0;
2820 }
2821 
2822 static int get_xctrl(struct slgt_info *info, int __user *xctrl)
2823 {
2824 	DBGINFO(("%s get_xctrl=%x\n", info->device_name, info->xctrl));
2825 	if (put_user(info->xctrl, xctrl))
2826 		return -EFAULT;
2827 	return 0;
2828 }
2829 
2830 /*
2831  * set extended control options
2832  *
2833  * xctrl[31:19] reserved, must be zero
2834  * xctrl[18:17] extended sync pattern length in bytes
2835  *              00 = 1 byte  in xsr[7:0]
2836  *              01 = 2 bytes in xsr[15:0]
2837  *              10 = 3 bytes in xsr[23:0]
2838  *              11 = 4 bytes in xsr[31:0]
2839  * xctrl[16]    1 = enable terminal count, 0=disabled
2840  * xctrl[15:0]  receive terminal count for fixed length packets
2841  *              value is count minus one (0 = 1 byte packet)
2842  *              when terminal count is reached, receiver
2843  *              automatically returns to hunt mode and receive
2844  *              FIFO contents are flushed to DMA buffers with
2845  *              end of frame (EOF) status
2846  */
2847 static int set_xctrl(struct slgt_info *info, int xctrl)
2848 {
2849 	unsigned long flags;
2850 
2851 	DBGINFO(("%s set_xctrl=%x)\n", info->device_name, xctrl));
2852 	spin_lock_irqsave(&info->lock, flags);
2853 	info->xctrl = xctrl;
2854 	wr_reg32(info, XCR, xctrl);
2855 	spin_unlock_irqrestore(&info->lock, flags);
2856 	return 0;
2857 }
2858 
2859 /*
2860  * set general purpose IO pin state and direction
2861  *
2862  * user_gpio fields:
2863  * state   each bit indicates a pin state
2864  * smask   set bit indicates pin state to set
2865  * dir     each bit indicates a pin direction (0=input, 1=output)
2866  * dmask   set bit indicates pin direction to set
2867  */
2868 static int set_gpio(struct slgt_info *info, struct gpio_desc __user *user_gpio)
2869 {
2870  	unsigned long flags;
2871 	struct gpio_desc gpio;
2872 	__u32 data;
2873 
2874 	if (!info->gpio_present)
2875 		return -EINVAL;
2876 	if (copy_from_user(&gpio, user_gpio, sizeof(gpio)))
2877 		return -EFAULT;
2878 	DBGINFO(("%s set_gpio state=%08x smask=%08x dir=%08x dmask=%08x\n",
2879 		 info->device_name, gpio.state, gpio.smask,
2880 		 gpio.dir, gpio.dmask));
2881 
2882 	spin_lock_irqsave(&info->port_array[0]->lock, flags);
2883 	if (gpio.dmask) {
2884 		data = rd_reg32(info, IODR);
2885 		data |= gpio.dmask & gpio.dir;
2886 		data &= ~(gpio.dmask & ~gpio.dir);
2887 		wr_reg32(info, IODR, data);
2888 	}
2889 	if (gpio.smask) {
2890 		data = rd_reg32(info, IOVR);
2891 		data |= gpio.smask & gpio.state;
2892 		data &= ~(gpio.smask & ~gpio.state);
2893 		wr_reg32(info, IOVR, data);
2894 	}
2895 	spin_unlock_irqrestore(&info->port_array[0]->lock, flags);
2896 
2897 	return 0;
2898 }
2899 
2900 /*
2901  * get general purpose IO pin state and direction
2902  */
2903 static int get_gpio(struct slgt_info *info, struct gpio_desc __user *user_gpio)
2904 {
2905 	struct gpio_desc gpio;
2906 	if (!info->gpio_present)
2907 		return -EINVAL;
2908 	gpio.state = rd_reg32(info, IOVR);
2909 	gpio.smask = 0xffffffff;
2910 	gpio.dir   = rd_reg32(info, IODR);
2911 	gpio.dmask = 0xffffffff;
2912 	if (copy_to_user(user_gpio, &gpio, sizeof(gpio)))
2913 		return -EFAULT;
2914 	DBGINFO(("%s get_gpio state=%08x dir=%08x\n",
2915 		 info->device_name, gpio.state, gpio.dir));
2916 	return 0;
2917 }
2918 
2919 /*
2920  * conditional wait facility
2921  */
2922 static void init_cond_wait(struct cond_wait *w, unsigned int data)
2923 {
2924 	init_waitqueue_head(&w->q);
2925 	init_waitqueue_entry(&w->wait, current);
2926 	w->data = data;
2927 }
2928 
2929 static void add_cond_wait(struct cond_wait **head, struct cond_wait *w)
2930 {
2931 	set_current_state(TASK_INTERRUPTIBLE);
2932 	add_wait_queue(&w->q, &w->wait);
2933 	w->next = *head;
2934 	*head = w;
2935 }
2936 
2937 static void remove_cond_wait(struct cond_wait **head, struct cond_wait *cw)
2938 {
2939 	struct cond_wait *w, *prev;
2940 	remove_wait_queue(&cw->q, &cw->wait);
2941 	set_current_state(TASK_RUNNING);
2942 	for (w = *head, prev = NULL ; w != NULL ; prev = w, w = w->next) {
2943 		if (w == cw) {
2944 			if (prev != NULL)
2945 				prev->next = w->next;
2946 			else
2947 				*head = w->next;
2948 			break;
2949 		}
2950 	}
2951 }
2952 
2953 static void flush_cond_wait(struct cond_wait **head)
2954 {
2955 	while (*head != NULL) {
2956 		wake_up_interruptible(&(*head)->q);
2957 		*head = (*head)->next;
2958 	}
2959 }
2960 
2961 /*
2962  * wait for general purpose I/O pin(s) to enter specified state
2963  *
2964  * user_gpio fields:
2965  * state - bit indicates target pin state
2966  * smask - set bit indicates watched pin
2967  *
2968  * The wait ends when at least one watched pin enters the specified
2969  * state. When 0 (no error) is returned, user_gpio->state is set to the
2970  * state of all GPIO pins when the wait ends.
2971  *
2972  * Note: Each pin may be a dedicated input, dedicated output, or
2973  * configurable input/output. The number and configuration of pins
2974  * varies with the specific adapter model. Only input pins (dedicated
2975  * or configured) can be monitored with this function.
2976  */
2977 static int wait_gpio(struct slgt_info *info, struct gpio_desc __user *user_gpio)
2978 {
2979  	unsigned long flags;
2980 	int rc = 0;
2981 	struct gpio_desc gpio;
2982 	struct cond_wait wait;
2983 	u32 state;
2984 
2985 	if (!info->gpio_present)
2986 		return -EINVAL;
2987 	if (copy_from_user(&gpio, user_gpio, sizeof(gpio)))
2988 		return -EFAULT;
2989 	DBGINFO(("%s wait_gpio() state=%08x smask=%08x\n",
2990 		 info->device_name, gpio.state, gpio.smask));
2991 	/* ignore output pins identified by set IODR bit */
2992 	if ((gpio.smask &= ~rd_reg32(info, IODR)) == 0)
2993 		return -EINVAL;
2994 	init_cond_wait(&wait, gpio.smask);
2995 
2996 	spin_lock_irqsave(&info->port_array[0]->lock, flags);
2997 	/* enable interrupts for watched pins */
2998 	wr_reg32(info, IOER, rd_reg32(info, IOER) | gpio.smask);
2999 	/* get current pin states */
3000 	state = rd_reg32(info, IOVR);
3001 
3002 	if (gpio.smask & ~(state ^ gpio.state)) {
3003 		/* already in target state */
3004 		gpio.state = state;
3005 	} else {
3006 		/* wait for target state */
3007 		add_cond_wait(&info->gpio_wait_q, &wait);
3008 		spin_unlock_irqrestore(&info->port_array[0]->lock, flags);
3009 		schedule();
3010 		if (signal_pending(current))
3011 			rc = -ERESTARTSYS;
3012 		else
3013 			gpio.state = wait.data;
3014 		spin_lock_irqsave(&info->port_array[0]->lock, flags);
3015 		remove_cond_wait(&info->gpio_wait_q, &wait);
3016 	}
3017 
3018 	/* disable all GPIO interrupts if no waiting processes */
3019 	if (info->gpio_wait_q == NULL)
3020 		wr_reg32(info, IOER, 0);
3021 	spin_unlock_irqrestore(&info->port_array[0]->lock, flags);
3022 
3023 	if ((rc == 0) && copy_to_user(user_gpio, &gpio, sizeof(gpio)))
3024 		rc = -EFAULT;
3025 	return rc;
3026 }
3027 
3028 static int modem_input_wait(struct slgt_info *info,int arg)
3029 {
3030  	unsigned long flags;
3031 	int rc;
3032 	struct mgsl_icount cprev, cnow;
3033 	DECLARE_WAITQUEUE(wait, current);
3034 
3035 	/* save current irq counts */
3036 	spin_lock_irqsave(&info->lock,flags);
3037 	cprev = info->icount;
3038 	add_wait_queue(&info->status_event_wait_q, &wait);
3039 	set_current_state(TASK_INTERRUPTIBLE);
3040 	spin_unlock_irqrestore(&info->lock,flags);
3041 
3042 	for(;;) {
3043 		schedule();
3044 		if (signal_pending(current)) {
3045 			rc = -ERESTARTSYS;
3046 			break;
3047 		}
3048 
3049 		/* get new irq counts */
3050 		spin_lock_irqsave(&info->lock,flags);
3051 		cnow = info->icount;
3052 		set_current_state(TASK_INTERRUPTIBLE);
3053 		spin_unlock_irqrestore(&info->lock,flags);
3054 
3055 		/* if no change, wait aborted for some reason */
3056 		if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
3057 		    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
3058 			rc = -EIO;
3059 			break;
3060 		}
3061 
3062 		/* check for change in caller specified modem input */
3063 		if ((arg & TIOCM_RNG && cnow.rng != cprev.rng) ||
3064 		    (arg & TIOCM_DSR && cnow.dsr != cprev.dsr) ||
3065 		    (arg & TIOCM_CD  && cnow.dcd != cprev.dcd) ||
3066 		    (arg & TIOCM_CTS && cnow.cts != cprev.cts)) {
3067 			rc = 0;
3068 			break;
3069 		}
3070 
3071 		cprev = cnow;
3072 	}
3073 	remove_wait_queue(&info->status_event_wait_q, &wait);
3074 	set_current_state(TASK_RUNNING);
3075 	return rc;
3076 }
3077 
3078 /*
3079  *  return state of serial control and status signals
3080  */
3081 static int tiocmget(struct tty_struct *tty)
3082 {
3083 	struct slgt_info *info = tty->driver_data;
3084 	unsigned int result;
3085  	unsigned long flags;
3086 
3087 	spin_lock_irqsave(&info->lock,flags);
3088  	get_signals(info);
3089 	spin_unlock_irqrestore(&info->lock,flags);
3090 
3091 	result = ((info->signals & SerialSignal_RTS) ? TIOCM_RTS:0) +
3092 		((info->signals & SerialSignal_DTR) ? TIOCM_DTR:0) +
3093 		((info->signals & SerialSignal_DCD) ? TIOCM_CAR:0) +
3094 		((info->signals & SerialSignal_RI)  ? TIOCM_RNG:0) +
3095 		((info->signals & SerialSignal_DSR) ? TIOCM_DSR:0) +
3096 		((info->signals & SerialSignal_CTS) ? TIOCM_CTS:0);
3097 
3098 	DBGINFO(("%s tiocmget value=%08X\n", info->device_name, result));
3099 	return result;
3100 }
3101 
3102 /*
3103  * set modem control signals (DTR/RTS)
3104  *
3105  * 	cmd	signal command: TIOCMBIS = set bit TIOCMBIC = clear bit
3106  *		TIOCMSET = set/clear signal values
3107  * 	value	bit mask for command
3108  */
3109 static int tiocmset(struct tty_struct *tty,
3110 		    unsigned int set, unsigned int clear)
3111 {
3112 	struct slgt_info *info = tty->driver_data;
3113  	unsigned long flags;
3114 
3115 	DBGINFO(("%s tiocmset(%x,%x)\n", info->device_name, set, clear));
3116 
3117 	if (set & TIOCM_RTS)
3118 		info->signals |= SerialSignal_RTS;
3119 	if (set & TIOCM_DTR)
3120 		info->signals |= SerialSignal_DTR;
3121 	if (clear & TIOCM_RTS)
3122 		info->signals &= ~SerialSignal_RTS;
3123 	if (clear & TIOCM_DTR)
3124 		info->signals &= ~SerialSignal_DTR;
3125 
3126 	spin_lock_irqsave(&info->lock,flags);
3127 	set_signals(info);
3128 	spin_unlock_irqrestore(&info->lock,flags);
3129 	return 0;
3130 }
3131 
3132 static int carrier_raised(struct tty_port *port)
3133 {
3134 	unsigned long flags;
3135 	struct slgt_info *info = container_of(port, struct slgt_info, port);
3136 
3137 	spin_lock_irqsave(&info->lock,flags);
3138 	get_signals(info);
3139 	spin_unlock_irqrestore(&info->lock,flags);
3140 	return (info->signals & SerialSignal_DCD) ? 1 : 0;
3141 }
3142 
3143 static void dtr_rts(struct tty_port *port, int on)
3144 {
3145 	unsigned long flags;
3146 	struct slgt_info *info = container_of(port, struct slgt_info, port);
3147 
3148 	spin_lock_irqsave(&info->lock,flags);
3149 	if (on)
3150 		info->signals |= SerialSignal_RTS | SerialSignal_DTR;
3151 	else
3152 		info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
3153 	set_signals(info);
3154 	spin_unlock_irqrestore(&info->lock,flags);
3155 }
3156 
3157 
3158 /*
3159  *  block current process until the device is ready to open
3160  */
3161 static int block_til_ready(struct tty_struct *tty, struct file *filp,
3162 			   struct slgt_info *info)
3163 {
3164 	DECLARE_WAITQUEUE(wait, current);
3165 	int		retval;
3166 	bool		do_clocal = false;
3167 	unsigned long	flags;
3168 	int		cd;
3169 	struct tty_port *port = &info->port;
3170 
3171 	DBGINFO(("%s block_til_ready\n", tty->driver->name));
3172 
3173 	if (filp->f_flags & O_NONBLOCK || tty_io_error(tty)) {
3174 		/* nonblock mode is set or port is not enabled */
3175 		tty_port_set_active(port, 1);
3176 		return 0;
3177 	}
3178 
3179 	if (C_CLOCAL(tty))
3180 		do_clocal = true;
3181 
3182 	/* Wait for carrier detect and the line to become
3183 	 * free (i.e., not in use by the callout).  While we are in
3184 	 * this loop, port->count is dropped by one, so that
3185 	 * close() knows when to free things.  We restore it upon
3186 	 * exit, either normal or abnormal.
3187 	 */
3188 
3189 	retval = 0;
3190 	add_wait_queue(&port->open_wait, &wait);
3191 
3192 	spin_lock_irqsave(&info->lock, flags);
3193 	port->count--;
3194 	spin_unlock_irqrestore(&info->lock, flags);
3195 	port->blocked_open++;
3196 
3197 	while (1) {
3198 		if (C_BAUD(tty) && tty_port_initialized(port))
3199 			tty_port_raise_dtr_rts(port);
3200 
3201 		set_current_state(TASK_INTERRUPTIBLE);
3202 
3203 		if (tty_hung_up_p(filp) || !tty_port_initialized(port)) {
3204 			retval = (port->flags & ASYNC_HUP_NOTIFY) ?
3205 					-EAGAIN : -ERESTARTSYS;
3206 			break;
3207 		}
3208 
3209 		cd = tty_port_carrier_raised(port);
3210 		if (do_clocal || cd)
3211 			break;
3212 
3213 		if (signal_pending(current)) {
3214 			retval = -ERESTARTSYS;
3215 			break;
3216 		}
3217 
3218 		DBGINFO(("%s block_til_ready wait\n", tty->driver->name));
3219 		tty_unlock(tty);
3220 		schedule();
3221 		tty_lock(tty);
3222 	}
3223 
3224 	set_current_state(TASK_RUNNING);
3225 	remove_wait_queue(&port->open_wait, &wait);
3226 
3227 	if (!tty_hung_up_p(filp))
3228 		port->count++;
3229 	port->blocked_open--;
3230 
3231 	if (!retval)
3232 		tty_port_set_active(port, 1);
3233 
3234 	DBGINFO(("%s block_til_ready ready, rc=%d\n", tty->driver->name, retval));
3235 	return retval;
3236 }
3237 
3238 /*
3239  * allocate buffers used for calling line discipline receive_buf
3240  * directly in synchronous mode
3241  * note: add 5 bytes to max frame size to allow appending
3242  * 32-bit CRC and status byte when configured to do so
3243  */
3244 static int alloc_tmp_rbuf(struct slgt_info *info)
3245 {
3246 	info->tmp_rbuf = kmalloc(info->max_frame_size + 5, GFP_KERNEL);
3247 	if (info->tmp_rbuf == NULL)
3248 		return -ENOMEM;
3249 	/* unused flag buffer to satisfy receive_buf calling interface */
3250 	info->flag_buf = kzalloc(info->max_frame_size + 5, GFP_KERNEL);
3251 	if (!info->flag_buf) {
3252 		kfree(info->tmp_rbuf);
3253 		info->tmp_rbuf = NULL;
3254 		return -ENOMEM;
3255 	}
3256 	return 0;
3257 }
3258 
3259 static void free_tmp_rbuf(struct slgt_info *info)
3260 {
3261 	kfree(info->tmp_rbuf);
3262 	info->tmp_rbuf = NULL;
3263 	kfree(info->flag_buf);
3264 	info->flag_buf = NULL;
3265 }
3266 
3267 /*
3268  * allocate DMA descriptor lists.
3269  */
3270 static int alloc_desc(struct slgt_info *info)
3271 {
3272 	unsigned int i;
3273 	unsigned int pbufs;
3274 
3275 	/* allocate memory to hold descriptor lists */
3276 	info->bufs = dma_alloc_coherent(&info->pdev->dev, DESC_LIST_SIZE,
3277 					&info->bufs_dma_addr, GFP_KERNEL);
3278 	if (info->bufs == NULL)
3279 		return -ENOMEM;
3280 
3281 	info->rbufs = (struct slgt_desc*)info->bufs;
3282 	info->tbufs = ((struct slgt_desc*)info->bufs) + info->rbuf_count;
3283 
3284 	pbufs = (unsigned int)info->bufs_dma_addr;
3285 
3286 	/*
3287 	 * Build circular lists of descriptors
3288 	 */
3289 
3290 	for (i=0; i < info->rbuf_count; i++) {
3291 		/* physical address of this descriptor */
3292 		info->rbufs[i].pdesc = pbufs + (i * sizeof(struct slgt_desc));
3293 
3294 		/* physical address of next descriptor */
3295 		if (i == info->rbuf_count - 1)
3296 			info->rbufs[i].next = cpu_to_le32(pbufs);
3297 		else
3298 			info->rbufs[i].next = cpu_to_le32(pbufs + ((i+1) * sizeof(struct slgt_desc)));
3299 		set_desc_count(info->rbufs[i], DMABUFSIZE);
3300 	}
3301 
3302 	for (i=0; i < info->tbuf_count; i++) {
3303 		/* physical address of this descriptor */
3304 		info->tbufs[i].pdesc = pbufs + ((info->rbuf_count + i) * sizeof(struct slgt_desc));
3305 
3306 		/* physical address of next descriptor */
3307 		if (i == info->tbuf_count - 1)
3308 			info->tbufs[i].next = cpu_to_le32(pbufs + info->rbuf_count * sizeof(struct slgt_desc));
3309 		else
3310 			info->tbufs[i].next = cpu_to_le32(pbufs + ((info->rbuf_count + i + 1) * sizeof(struct slgt_desc)));
3311 	}
3312 
3313 	return 0;
3314 }
3315 
3316 static void free_desc(struct slgt_info *info)
3317 {
3318 	if (info->bufs != NULL) {
3319 		dma_free_coherent(&info->pdev->dev, DESC_LIST_SIZE,
3320 				  info->bufs, info->bufs_dma_addr);
3321 		info->bufs  = NULL;
3322 		info->rbufs = NULL;
3323 		info->tbufs = NULL;
3324 	}
3325 }
3326 
3327 static int alloc_bufs(struct slgt_info *info, struct slgt_desc *bufs, int count)
3328 {
3329 	int i;
3330 	for (i=0; i < count; i++) {
3331 		bufs[i].buf = dma_alloc_coherent(&info->pdev->dev, DMABUFSIZE,
3332 						 &bufs[i].buf_dma_addr, GFP_KERNEL);
3333 		if (!bufs[i].buf)
3334 			return -ENOMEM;
3335 		bufs[i].pbuf  = cpu_to_le32((unsigned int)bufs[i].buf_dma_addr);
3336 	}
3337 	return 0;
3338 }
3339 
3340 static void free_bufs(struct slgt_info *info, struct slgt_desc *bufs, int count)
3341 {
3342 	int i;
3343 	for (i=0; i < count; i++) {
3344 		if (bufs[i].buf == NULL)
3345 			continue;
3346 		dma_free_coherent(&info->pdev->dev, DMABUFSIZE, bufs[i].buf,
3347 				  bufs[i].buf_dma_addr);
3348 		bufs[i].buf = NULL;
3349 	}
3350 }
3351 
3352 static int alloc_dma_bufs(struct slgt_info *info)
3353 {
3354 	info->rbuf_count = 32;
3355 	info->tbuf_count = 32;
3356 
3357 	if (alloc_desc(info) < 0 ||
3358 	    alloc_bufs(info, info->rbufs, info->rbuf_count) < 0 ||
3359 	    alloc_bufs(info, info->tbufs, info->tbuf_count) < 0 ||
3360 	    alloc_tmp_rbuf(info) < 0) {
3361 		DBGERR(("%s DMA buffer alloc fail\n", info->device_name));
3362 		return -ENOMEM;
3363 	}
3364 	reset_rbufs(info);
3365 	return 0;
3366 }
3367 
3368 static void free_dma_bufs(struct slgt_info *info)
3369 {
3370 	if (info->bufs) {
3371 		free_bufs(info, info->rbufs, info->rbuf_count);
3372 		free_bufs(info, info->tbufs, info->tbuf_count);
3373 		free_desc(info);
3374 	}
3375 	free_tmp_rbuf(info);
3376 }
3377 
3378 static int claim_resources(struct slgt_info *info)
3379 {
3380 	if (request_mem_region(info->phys_reg_addr, SLGT_REG_SIZE, "synclink_gt") == NULL) {
3381 		DBGERR(("%s reg addr conflict, addr=%08X\n",
3382 			info->device_name, info->phys_reg_addr));
3383 		info->init_error = DiagStatus_AddressConflict;
3384 		goto errout;
3385 	}
3386 	else
3387 		info->reg_addr_requested = true;
3388 
3389 	info->reg_addr = ioremap(info->phys_reg_addr, SLGT_REG_SIZE);
3390 	if (!info->reg_addr) {
3391 		DBGERR(("%s can't map device registers, addr=%08X\n",
3392 			info->device_name, info->phys_reg_addr));
3393 		info->init_error = DiagStatus_CantAssignPciResources;
3394 		goto errout;
3395 	}
3396 	return 0;
3397 
3398 errout:
3399 	release_resources(info);
3400 	return -ENODEV;
3401 }
3402 
3403 static void release_resources(struct slgt_info *info)
3404 {
3405 	if (info->irq_requested) {
3406 		free_irq(info->irq_level, info);
3407 		info->irq_requested = false;
3408 	}
3409 
3410 	if (info->reg_addr_requested) {
3411 		release_mem_region(info->phys_reg_addr, SLGT_REG_SIZE);
3412 		info->reg_addr_requested = false;
3413 	}
3414 
3415 	if (info->reg_addr) {
3416 		iounmap(info->reg_addr);
3417 		info->reg_addr = NULL;
3418 	}
3419 }
3420 
3421 /* Add the specified device instance data structure to the
3422  * global linked list of devices and increment the device count.
3423  */
3424 static void add_device(struct slgt_info *info)
3425 {
3426 	char *devstr;
3427 
3428 	info->next_device = NULL;
3429 	info->line = slgt_device_count;
3430 	sprintf(info->device_name, "%s%d", tty_dev_prefix, info->line);
3431 
3432 	if (info->line < MAX_DEVICES) {
3433 		if (maxframe[info->line])
3434 			info->max_frame_size = maxframe[info->line];
3435 	}
3436 
3437 	slgt_device_count++;
3438 
3439 	if (!slgt_device_list)
3440 		slgt_device_list = info;
3441 	else {
3442 		struct slgt_info *current_dev = slgt_device_list;
3443 		while(current_dev->next_device)
3444 			current_dev = current_dev->next_device;
3445 		current_dev->next_device = info;
3446 	}
3447 
3448 	if (info->max_frame_size < 4096)
3449 		info->max_frame_size = 4096;
3450 	else if (info->max_frame_size > 65535)
3451 		info->max_frame_size = 65535;
3452 
3453 	switch(info->pdev->device) {
3454 	case SYNCLINK_GT_DEVICE_ID:
3455 		devstr = "GT";
3456 		break;
3457 	case SYNCLINK_GT2_DEVICE_ID:
3458 		devstr = "GT2";
3459 		break;
3460 	case SYNCLINK_GT4_DEVICE_ID:
3461 		devstr = "GT4";
3462 		break;
3463 	case SYNCLINK_AC_DEVICE_ID:
3464 		devstr = "AC";
3465 		info->params.mode = MGSL_MODE_ASYNC;
3466 		break;
3467 	default:
3468 		devstr = "(unknown model)";
3469 	}
3470 	printk("SyncLink %s %s IO=%08x IRQ=%d MaxFrameSize=%u\n",
3471 		devstr, info->device_name, info->phys_reg_addr,
3472 		info->irq_level, info->max_frame_size);
3473 
3474 #if SYNCLINK_GENERIC_HDLC
3475 	hdlcdev_init(info);
3476 #endif
3477 }
3478 
3479 static const struct tty_port_operations slgt_port_ops = {
3480 	.carrier_raised = carrier_raised,
3481 	.dtr_rts = dtr_rts,
3482 };
3483 
3484 /*
3485  *  allocate device instance structure, return NULL on failure
3486  */
3487 static struct slgt_info *alloc_dev(int adapter_num, int port_num, struct pci_dev *pdev)
3488 {
3489 	struct slgt_info *info;
3490 
3491 	info = kzalloc(sizeof(struct slgt_info), GFP_KERNEL);
3492 
3493 	if (!info) {
3494 		DBGERR(("%s device alloc failed adapter=%d port=%d\n",
3495 			driver_name, adapter_num, port_num));
3496 	} else {
3497 		tty_port_init(&info->port);
3498 		info->port.ops = &slgt_port_ops;
3499 		info->magic = MGSL_MAGIC;
3500 		INIT_WORK(&info->task, bh_handler);
3501 		info->max_frame_size = 4096;
3502 		info->base_clock = 14745600;
3503 		info->rbuf_fill_level = DMABUFSIZE;
3504 		init_waitqueue_head(&info->status_event_wait_q);
3505 		init_waitqueue_head(&info->event_wait_q);
3506 		spin_lock_init(&info->netlock);
3507 		memcpy(&info->params,&default_params,sizeof(MGSL_PARAMS));
3508 		info->idle_mode = HDLC_TXIDLE_FLAGS;
3509 		info->adapter_num = adapter_num;
3510 		info->port_num = port_num;
3511 
3512 		timer_setup(&info->tx_timer, tx_timeout, 0);
3513 		timer_setup(&info->rx_timer, rx_timeout, 0);
3514 
3515 		/* Copy configuration info to device instance data */
3516 		info->pdev = pdev;
3517 		info->irq_level = pdev->irq;
3518 		info->phys_reg_addr = pci_resource_start(pdev,0);
3519 
3520 		info->bus_type = MGSL_BUS_TYPE_PCI;
3521 		info->irq_flags = IRQF_SHARED;
3522 
3523 		info->init_error = -1; /* assume error, set to 0 on successful init */
3524 	}
3525 
3526 	return info;
3527 }
3528 
3529 static void device_init(int adapter_num, struct pci_dev *pdev)
3530 {
3531 	struct slgt_info *port_array[SLGT_MAX_PORTS];
3532 	int i;
3533 	int port_count = 1;
3534 
3535 	if (pdev->device == SYNCLINK_GT2_DEVICE_ID)
3536 		port_count = 2;
3537 	else if (pdev->device == SYNCLINK_GT4_DEVICE_ID)
3538 		port_count = 4;
3539 
3540 	/* allocate device instances for all ports */
3541 	for (i=0; i < port_count; ++i) {
3542 		port_array[i] = alloc_dev(adapter_num, i, pdev);
3543 		if (port_array[i] == NULL) {
3544 			for (--i; i >= 0; --i) {
3545 				tty_port_destroy(&port_array[i]->port);
3546 				kfree(port_array[i]);
3547 			}
3548 			return;
3549 		}
3550 	}
3551 
3552 	/* give copy of port_array to all ports and add to device list  */
3553 	for (i=0; i < port_count; ++i) {
3554 		memcpy(port_array[i]->port_array, port_array, sizeof(port_array));
3555 		add_device(port_array[i]);
3556 		port_array[i]->port_count = port_count;
3557 		spin_lock_init(&port_array[i]->lock);
3558 	}
3559 
3560 	/* Allocate and claim adapter resources */
3561 	if (!claim_resources(port_array[0])) {
3562 
3563 		alloc_dma_bufs(port_array[0]);
3564 
3565 		/* copy resource information from first port to others */
3566 		for (i = 1; i < port_count; ++i) {
3567 			port_array[i]->irq_level = port_array[0]->irq_level;
3568 			port_array[i]->reg_addr  = port_array[0]->reg_addr;
3569 			alloc_dma_bufs(port_array[i]);
3570 		}
3571 
3572 		if (request_irq(port_array[0]->irq_level,
3573 					slgt_interrupt,
3574 					port_array[0]->irq_flags,
3575 					port_array[0]->device_name,
3576 					port_array[0]) < 0) {
3577 			DBGERR(("%s request_irq failed IRQ=%d\n",
3578 				port_array[0]->device_name,
3579 				port_array[0]->irq_level));
3580 		} else {
3581 			port_array[0]->irq_requested = true;
3582 			adapter_test(port_array[0]);
3583 			for (i=1 ; i < port_count ; i++) {
3584 				port_array[i]->init_error = port_array[0]->init_error;
3585 				port_array[i]->gpio_present = port_array[0]->gpio_present;
3586 			}
3587 		}
3588 	}
3589 
3590 	for (i = 0; i < port_count; ++i) {
3591 		struct slgt_info *info = port_array[i];
3592 		tty_port_register_device(&info->port, serial_driver, info->line,
3593 				&info->pdev->dev);
3594 	}
3595 }
3596 
3597 static int init_one(struct pci_dev *dev,
3598 			      const struct pci_device_id *ent)
3599 {
3600 	if (pci_enable_device(dev)) {
3601 		printk("error enabling pci device %p\n", dev);
3602 		return -EIO;
3603 	}
3604 	pci_set_master(dev);
3605 	device_init(slgt_device_count, dev);
3606 	return 0;
3607 }
3608 
3609 static void remove_one(struct pci_dev *dev)
3610 {
3611 }
3612 
3613 static const struct tty_operations ops = {
3614 	.open = open,
3615 	.close = close,
3616 	.write = write,
3617 	.put_char = put_char,
3618 	.flush_chars = flush_chars,
3619 	.write_room = write_room,
3620 	.chars_in_buffer = chars_in_buffer,
3621 	.flush_buffer = flush_buffer,
3622 	.ioctl = ioctl,
3623 	.compat_ioctl = slgt_compat_ioctl,
3624 	.throttle = throttle,
3625 	.unthrottle = unthrottle,
3626 	.send_xchar = send_xchar,
3627 	.break_ctl = set_break,
3628 	.wait_until_sent = wait_until_sent,
3629 	.set_termios = set_termios,
3630 	.stop = tx_hold,
3631 	.start = tx_release,
3632 	.hangup = hangup,
3633 	.tiocmget = tiocmget,
3634 	.tiocmset = tiocmset,
3635 	.get_icount = get_icount,
3636 	.proc_show = synclink_gt_proc_show,
3637 };
3638 
3639 static void slgt_cleanup(void)
3640 {
3641 	struct slgt_info *info;
3642 	struct slgt_info *tmp;
3643 
3644 	printk(KERN_INFO "unload %s\n", driver_name);
3645 
3646 	if (serial_driver) {
3647 		for (info=slgt_device_list ; info != NULL ; info=info->next_device)
3648 			tty_unregister_device(serial_driver, info->line);
3649 		tty_unregister_driver(serial_driver);
3650 		tty_driver_kref_put(serial_driver);
3651 	}
3652 
3653 	/* reset devices */
3654 	info = slgt_device_list;
3655 	while(info) {
3656 		reset_port(info);
3657 		info = info->next_device;
3658 	}
3659 
3660 	/* release devices */
3661 	info = slgt_device_list;
3662 	while(info) {
3663 #if SYNCLINK_GENERIC_HDLC
3664 		hdlcdev_exit(info);
3665 #endif
3666 		free_dma_bufs(info);
3667 		free_tmp_rbuf(info);
3668 		if (info->port_num == 0)
3669 			release_resources(info);
3670 		tmp = info;
3671 		info = info->next_device;
3672 		tty_port_destroy(&tmp->port);
3673 		kfree(tmp);
3674 	}
3675 
3676 	if (pci_registered)
3677 		pci_unregister_driver(&pci_driver);
3678 }
3679 
3680 /*
3681  *  Driver initialization entry point.
3682  */
3683 static int __init slgt_init(void)
3684 {
3685 	int rc;
3686 
3687 	printk(KERN_INFO "%s\n", driver_name);
3688 
3689 	serial_driver = tty_alloc_driver(MAX_DEVICES, TTY_DRIVER_REAL_RAW |
3690 			TTY_DRIVER_DYNAMIC_DEV);
3691 	if (IS_ERR(serial_driver)) {
3692 		printk("%s can't allocate tty driver\n", driver_name);
3693 		return PTR_ERR(serial_driver);
3694 	}
3695 
3696 	/* Initialize the tty_driver structure */
3697 
3698 	serial_driver->driver_name = slgt_driver_name;
3699 	serial_driver->name = tty_dev_prefix;
3700 	serial_driver->major = ttymajor;
3701 	serial_driver->minor_start = 64;
3702 	serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
3703 	serial_driver->subtype = SERIAL_TYPE_NORMAL;
3704 	serial_driver->init_termios = tty_std_termios;
3705 	serial_driver->init_termios.c_cflag =
3706 		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
3707 	serial_driver->init_termios.c_ispeed = 9600;
3708 	serial_driver->init_termios.c_ospeed = 9600;
3709 	tty_set_operations(serial_driver, &ops);
3710 	if ((rc = tty_register_driver(serial_driver)) < 0) {
3711 		DBGERR(("%s can't register serial driver\n", driver_name));
3712 		tty_driver_kref_put(serial_driver);
3713 		serial_driver = NULL;
3714 		goto error;
3715 	}
3716 
3717 	printk(KERN_INFO "%s, tty major#%d\n",
3718 	       driver_name, serial_driver->major);
3719 
3720 	slgt_device_count = 0;
3721 	if ((rc = pci_register_driver(&pci_driver)) < 0) {
3722 		printk("%s pci_register_driver error=%d\n", driver_name, rc);
3723 		goto error;
3724 	}
3725 	pci_registered = true;
3726 
3727 	if (!slgt_device_list)
3728 		printk("%s no devices found\n",driver_name);
3729 
3730 	return 0;
3731 
3732 error:
3733 	slgt_cleanup();
3734 	return rc;
3735 }
3736 
3737 static void __exit slgt_exit(void)
3738 {
3739 	slgt_cleanup();
3740 }
3741 
3742 module_init(slgt_init);
3743 module_exit(slgt_exit);
3744 
3745 /*
3746  * register access routines
3747  */
3748 
3749 #define CALC_REGADDR() \
3750 	unsigned long reg_addr = ((unsigned long)info->reg_addr) + addr; \
3751 	if (addr >= 0x80) \
3752 		reg_addr += (info->port_num) * 32; \
3753 	else if (addr >= 0x40)	\
3754 		reg_addr += (info->port_num) * 16;
3755 
3756 static __u8 rd_reg8(struct slgt_info *info, unsigned int addr)
3757 {
3758 	CALC_REGADDR();
3759 	return readb((void __iomem *)reg_addr);
3760 }
3761 
3762 static void wr_reg8(struct slgt_info *info, unsigned int addr, __u8 value)
3763 {
3764 	CALC_REGADDR();
3765 	writeb(value, (void __iomem *)reg_addr);
3766 }
3767 
3768 static __u16 rd_reg16(struct slgt_info *info, unsigned int addr)
3769 {
3770 	CALC_REGADDR();
3771 	return readw((void __iomem *)reg_addr);
3772 }
3773 
3774 static void wr_reg16(struct slgt_info *info, unsigned int addr, __u16 value)
3775 {
3776 	CALC_REGADDR();
3777 	writew(value, (void __iomem *)reg_addr);
3778 }
3779 
3780 static __u32 rd_reg32(struct slgt_info *info, unsigned int addr)
3781 {
3782 	CALC_REGADDR();
3783 	return readl((void __iomem *)reg_addr);
3784 }
3785 
3786 static void wr_reg32(struct slgt_info *info, unsigned int addr, __u32 value)
3787 {
3788 	CALC_REGADDR();
3789 	writel(value, (void __iomem *)reg_addr);
3790 }
3791 
3792 static void rdma_reset(struct slgt_info *info)
3793 {
3794 	unsigned int i;
3795 
3796 	/* set reset bit */
3797 	wr_reg32(info, RDCSR, BIT1);
3798 
3799 	/* wait for enable bit cleared */
3800 	for(i=0 ; i < 1000 ; i++)
3801 		if (!(rd_reg32(info, RDCSR) & BIT0))
3802 			break;
3803 }
3804 
3805 static void tdma_reset(struct slgt_info *info)
3806 {
3807 	unsigned int i;
3808 
3809 	/* set reset bit */
3810 	wr_reg32(info, TDCSR, BIT1);
3811 
3812 	/* wait for enable bit cleared */
3813 	for(i=0 ; i < 1000 ; i++)
3814 		if (!(rd_reg32(info, TDCSR) & BIT0))
3815 			break;
3816 }
3817 
3818 /*
3819  * enable internal loopback
3820  * TxCLK and RxCLK are generated from BRG
3821  * and TxD is looped back to RxD internally.
3822  */
3823 static void enable_loopback(struct slgt_info *info)
3824 {
3825 	/* SCR (serial control) BIT2=loopback enable */
3826 	wr_reg16(info, SCR, (unsigned short)(rd_reg16(info, SCR) | BIT2));
3827 
3828 	if (info->params.mode != MGSL_MODE_ASYNC) {
3829 		/* CCR (clock control)
3830 		 * 07..05  tx clock source (010 = BRG)
3831 		 * 04..02  rx clock source (010 = BRG)
3832 		 * 01      auxclk enable   (0 = disable)
3833 		 * 00      BRG enable      (1 = enable)
3834 		 *
3835 		 * 0100 1001
3836 		 */
3837 		wr_reg8(info, CCR, 0x49);
3838 
3839 		/* set speed if available, otherwise use default */
3840 		if (info->params.clock_speed)
3841 			set_rate(info, info->params.clock_speed);
3842 		else
3843 			set_rate(info, 3686400);
3844 	}
3845 }
3846 
3847 /*
3848  *  set baud rate generator to specified rate
3849  */
3850 static void set_rate(struct slgt_info *info, u32 rate)
3851 {
3852 	unsigned int div;
3853 	unsigned int osc = info->base_clock;
3854 
3855 	/* div = osc/rate - 1
3856 	 *
3857 	 * Round div up if osc/rate is not integer to
3858 	 * force to next slowest rate.
3859 	 */
3860 
3861 	if (rate) {
3862 		div = osc/rate;
3863 		if (!(osc % rate) && div)
3864 			div--;
3865 		wr_reg16(info, BDR, (unsigned short)div);
3866 	}
3867 }
3868 
3869 static void rx_stop(struct slgt_info *info)
3870 {
3871 	unsigned short val;
3872 
3873 	/* disable and reset receiver */
3874 	val = rd_reg16(info, RCR) & ~BIT1;          /* clear enable bit */
3875 	wr_reg16(info, RCR, (unsigned short)(val | BIT2)); /* set reset bit */
3876 	wr_reg16(info, RCR, val);                  /* clear reset bit */
3877 
3878 	slgt_irq_off(info, IRQ_RXOVER + IRQ_RXDATA + IRQ_RXIDLE);
3879 
3880 	/* clear pending rx interrupts */
3881 	wr_reg16(info, SSR, IRQ_RXIDLE + IRQ_RXOVER);
3882 
3883 	rdma_reset(info);
3884 
3885 	info->rx_enabled = false;
3886 	info->rx_restart = false;
3887 }
3888 
3889 static void rx_start(struct slgt_info *info)
3890 {
3891 	unsigned short val;
3892 
3893 	slgt_irq_off(info, IRQ_RXOVER + IRQ_RXDATA);
3894 
3895 	/* clear pending rx overrun IRQ */
3896 	wr_reg16(info, SSR, IRQ_RXOVER);
3897 
3898 	/* reset and disable receiver */
3899 	val = rd_reg16(info, RCR) & ~BIT1; /* clear enable bit */
3900 	wr_reg16(info, RCR, (unsigned short)(val | BIT2)); /* set reset bit */
3901 	wr_reg16(info, RCR, val);                  /* clear reset bit */
3902 
3903 	rdma_reset(info);
3904 	reset_rbufs(info);
3905 
3906 	if (info->rx_pio) {
3907 		/* rx request when rx FIFO not empty */
3908 		wr_reg16(info, SCR, (unsigned short)(rd_reg16(info, SCR) & ~BIT14));
3909 		slgt_irq_on(info, IRQ_RXDATA);
3910 		if (info->params.mode == MGSL_MODE_ASYNC) {
3911 			/* enable saving of rx status */
3912 			wr_reg32(info, RDCSR, BIT6);
3913 		}
3914 	} else {
3915 		/* rx request when rx FIFO half full */
3916 		wr_reg16(info, SCR, (unsigned short)(rd_reg16(info, SCR) | BIT14));
3917 		/* set 1st descriptor address */
3918 		wr_reg32(info, RDDAR, info->rbufs[0].pdesc);
3919 
3920 		if (info->params.mode != MGSL_MODE_ASYNC) {
3921 			/* enable rx DMA and DMA interrupt */
3922 			wr_reg32(info, RDCSR, (BIT2 + BIT0));
3923 		} else {
3924 			/* enable saving of rx status, rx DMA and DMA interrupt */
3925 			wr_reg32(info, RDCSR, (BIT6 + BIT2 + BIT0));
3926 		}
3927 	}
3928 
3929 	slgt_irq_on(info, IRQ_RXOVER);
3930 
3931 	/* enable receiver */
3932 	wr_reg16(info, RCR, (unsigned short)(rd_reg16(info, RCR) | BIT1));
3933 
3934 	info->rx_restart = false;
3935 	info->rx_enabled = true;
3936 }
3937 
3938 static void tx_start(struct slgt_info *info)
3939 {
3940 	if (!info->tx_enabled) {
3941 		wr_reg16(info, TCR,
3942 			 (unsigned short)((rd_reg16(info, TCR) | BIT1) & ~BIT2));
3943 		info->tx_enabled = true;
3944 	}
3945 
3946 	if (desc_count(info->tbufs[info->tbuf_start])) {
3947 		info->drop_rts_on_tx_done = false;
3948 
3949 		if (info->params.mode != MGSL_MODE_ASYNC) {
3950 			if (info->params.flags & HDLC_FLAG_AUTO_RTS) {
3951 				get_signals(info);
3952 				if (!(info->signals & SerialSignal_RTS)) {
3953 					info->signals |= SerialSignal_RTS;
3954 					set_signals(info);
3955 					info->drop_rts_on_tx_done = true;
3956 				}
3957 			}
3958 
3959 			slgt_irq_off(info, IRQ_TXDATA);
3960 			slgt_irq_on(info, IRQ_TXUNDER + IRQ_TXIDLE);
3961 			/* clear tx idle and underrun status bits */
3962 			wr_reg16(info, SSR, (unsigned short)(IRQ_TXIDLE + IRQ_TXUNDER));
3963 		} else {
3964 			slgt_irq_off(info, IRQ_TXDATA);
3965 			slgt_irq_on(info, IRQ_TXIDLE);
3966 			/* clear tx idle status bit */
3967 			wr_reg16(info, SSR, IRQ_TXIDLE);
3968 		}
3969 		/* set 1st descriptor address and start DMA */
3970 		wr_reg32(info, TDDAR, info->tbufs[info->tbuf_start].pdesc);
3971 		wr_reg32(info, TDCSR, BIT2 + BIT0);
3972 		info->tx_active = true;
3973 	}
3974 }
3975 
3976 static void tx_stop(struct slgt_info *info)
3977 {
3978 	unsigned short val;
3979 
3980 	del_timer(&info->tx_timer);
3981 
3982 	tdma_reset(info);
3983 
3984 	/* reset and disable transmitter */
3985 	val = rd_reg16(info, TCR) & ~BIT1;          /* clear enable bit */
3986 	wr_reg16(info, TCR, (unsigned short)(val | BIT2)); /* set reset bit */
3987 
3988 	slgt_irq_off(info, IRQ_TXDATA + IRQ_TXIDLE + IRQ_TXUNDER);
3989 
3990 	/* clear tx idle and underrun status bit */
3991 	wr_reg16(info, SSR, (unsigned short)(IRQ_TXIDLE + IRQ_TXUNDER));
3992 
3993 	reset_tbufs(info);
3994 
3995 	info->tx_enabled = false;
3996 	info->tx_active = false;
3997 }
3998 
3999 static void reset_port(struct slgt_info *info)
4000 {
4001 	if (!info->reg_addr)
4002 		return;
4003 
4004 	tx_stop(info);
4005 	rx_stop(info);
4006 
4007 	info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
4008 	set_signals(info);
4009 
4010 	slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);
4011 }
4012 
4013 static void reset_adapter(struct slgt_info *info)
4014 {
4015 	int i;
4016 	for (i=0; i < info->port_count; ++i) {
4017 		if (info->port_array[i])
4018 			reset_port(info->port_array[i]);
4019 	}
4020 }
4021 
4022 static void async_mode(struct slgt_info *info)
4023 {
4024   	unsigned short val;
4025 
4026 	slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);
4027 	tx_stop(info);
4028 	rx_stop(info);
4029 
4030 	/* TCR (tx control)
4031 	 *
4032 	 * 15..13  mode, 010=async
4033 	 * 12..10  encoding, 000=NRZ
4034 	 * 09      parity enable
4035 	 * 08      1=odd parity, 0=even parity
4036 	 * 07      1=RTS driver control
4037 	 * 06      1=break enable
4038 	 * 05..04  character length
4039 	 *         00=5 bits
4040 	 *         01=6 bits
4041 	 *         10=7 bits
4042 	 *         11=8 bits
4043 	 * 03      0=1 stop bit, 1=2 stop bits
4044 	 * 02      reset
4045 	 * 01      enable
4046 	 * 00      auto-CTS enable
4047 	 */
4048 	val = 0x4000;
4049 
4050 	if (info->if_mode & MGSL_INTERFACE_RTS_EN)
4051 		val |= BIT7;
4052 
4053 	if (info->params.parity != ASYNC_PARITY_NONE) {
4054 		val |= BIT9;
4055 		if (info->params.parity == ASYNC_PARITY_ODD)
4056 			val |= BIT8;
4057 	}
4058 
4059 	switch (info->params.data_bits)
4060 	{
4061 	case 6: val |= BIT4; break;
4062 	case 7: val |= BIT5; break;
4063 	case 8: val |= BIT5 + BIT4; break;
4064 	}
4065 
4066 	if (info->params.stop_bits != 1)
4067 		val |= BIT3;
4068 
4069 	if (info->params.flags & HDLC_FLAG_AUTO_CTS)
4070 		val |= BIT0;
4071 
4072 	wr_reg16(info, TCR, val);
4073 
4074 	/* RCR (rx control)
4075 	 *
4076 	 * 15..13  mode, 010=async
4077 	 * 12..10  encoding, 000=NRZ
4078 	 * 09      parity enable
4079 	 * 08      1=odd parity, 0=even parity
4080 	 * 07..06  reserved, must be 0
4081 	 * 05..04  character length
4082 	 *         00=5 bits
4083 	 *         01=6 bits
4084 	 *         10=7 bits
4085 	 *         11=8 bits
4086 	 * 03      reserved, must be zero
4087 	 * 02      reset
4088 	 * 01      enable
4089 	 * 00      auto-DCD enable
4090 	 */
4091 	val = 0x4000;
4092 
4093 	if (info->params.parity != ASYNC_PARITY_NONE) {
4094 		val |= BIT9;
4095 		if (info->params.parity == ASYNC_PARITY_ODD)
4096 			val |= BIT8;
4097 	}
4098 
4099 	switch (info->params.data_bits)
4100 	{
4101 	case 6: val |= BIT4; break;
4102 	case 7: val |= BIT5; break;
4103 	case 8: val |= BIT5 + BIT4; break;
4104 	}
4105 
4106 	if (info->params.flags & HDLC_FLAG_AUTO_DCD)
4107 		val |= BIT0;
4108 
4109 	wr_reg16(info, RCR, val);
4110 
4111 	/* CCR (clock control)
4112 	 *
4113 	 * 07..05  011 = tx clock source is BRG/16
4114 	 * 04..02  010 = rx clock source is BRG
4115 	 * 01      0 = auxclk disabled
4116 	 * 00      1 = BRG enabled
4117 	 *
4118 	 * 0110 1001
4119 	 */
4120 	wr_reg8(info, CCR, 0x69);
4121 
4122 	msc_set_vcr(info);
4123 
4124 	/* SCR (serial control)
4125 	 *
4126 	 * 15  1=tx req on FIFO half empty
4127 	 * 14  1=rx req on FIFO half full
4128 	 * 13  tx data  IRQ enable
4129 	 * 12  tx idle  IRQ enable
4130 	 * 11  rx break on IRQ enable
4131 	 * 10  rx data  IRQ enable
4132 	 * 09  rx break off IRQ enable
4133 	 * 08  overrun  IRQ enable
4134 	 * 07  DSR      IRQ enable
4135 	 * 06  CTS      IRQ enable
4136 	 * 05  DCD      IRQ enable
4137 	 * 04  RI       IRQ enable
4138 	 * 03  0=16x sampling, 1=8x sampling
4139 	 * 02  1=txd->rxd internal loopback enable
4140 	 * 01  reserved, must be zero
4141 	 * 00  1=master IRQ enable
4142 	 */
4143 	val = BIT15 + BIT14 + BIT0;
4144 	/* JCR[8] : 1 = x8 async mode feature available */
4145 	if ((rd_reg32(info, JCR) & BIT8) && info->params.data_rate &&
4146 	    ((info->base_clock < (info->params.data_rate * 16)) ||
4147 	     (info->base_clock % (info->params.data_rate * 16)))) {
4148 		/* use 8x sampling */
4149 		val |= BIT3;
4150 		set_rate(info, info->params.data_rate * 8);
4151 	} else {
4152 		/* use 16x sampling */
4153 		set_rate(info, info->params.data_rate * 16);
4154 	}
4155 	wr_reg16(info, SCR, val);
4156 
4157 	slgt_irq_on(info, IRQ_RXBREAK | IRQ_RXOVER);
4158 
4159 	if (info->params.loopback)
4160 		enable_loopback(info);
4161 }
4162 
4163 static void sync_mode(struct slgt_info *info)
4164 {
4165 	unsigned short val;
4166 
4167 	slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);
4168 	tx_stop(info);
4169 	rx_stop(info);
4170 
4171 	/* TCR (tx control)
4172 	 *
4173 	 * 15..13  mode
4174 	 *         000=HDLC/SDLC
4175 	 *         001=raw bit synchronous
4176 	 *         010=asynchronous/isochronous
4177 	 *         011=monosync byte synchronous
4178 	 *         100=bisync byte synchronous
4179 	 *         101=xsync byte synchronous
4180 	 * 12..10  encoding
4181 	 * 09      CRC enable
4182 	 * 08      CRC32
4183 	 * 07      1=RTS driver control
4184 	 * 06      preamble enable
4185 	 * 05..04  preamble length
4186 	 * 03      share open/close flag
4187 	 * 02      reset
4188 	 * 01      enable
4189 	 * 00      auto-CTS enable
4190 	 */
4191 	val = BIT2;
4192 
4193 	switch(info->params.mode) {
4194 	case MGSL_MODE_XSYNC:
4195 		val |= BIT15 + BIT13;
4196 		break;
4197 	case MGSL_MODE_MONOSYNC: val |= BIT14 + BIT13; break;
4198 	case MGSL_MODE_BISYNC:   val |= BIT15; break;
4199 	case MGSL_MODE_RAW:      val |= BIT13; break;
4200 	}
4201 	if (info->if_mode & MGSL_INTERFACE_RTS_EN)
4202 		val |= BIT7;
4203 
4204 	switch(info->params.encoding)
4205 	{
4206 	case HDLC_ENCODING_NRZB:          val |= BIT10; break;
4207 	case HDLC_ENCODING_NRZI_MARK:     val |= BIT11; break;
4208 	case HDLC_ENCODING_NRZI:          val |= BIT11 + BIT10; break;
4209 	case HDLC_ENCODING_BIPHASE_MARK:  val |= BIT12; break;
4210 	case HDLC_ENCODING_BIPHASE_SPACE: val |= BIT12 + BIT10; break;
4211 	case HDLC_ENCODING_BIPHASE_LEVEL: val |= BIT12 + BIT11; break;
4212 	case HDLC_ENCODING_DIFF_BIPHASE_LEVEL: val |= BIT12 + BIT11 + BIT10; break;
4213 	}
4214 
4215 	switch (info->params.crc_type & HDLC_CRC_MASK)
4216 	{
4217 	case HDLC_CRC_16_CCITT: val |= BIT9; break;
4218 	case HDLC_CRC_32_CCITT: val |= BIT9 + BIT8; break;
4219 	}
4220 
4221 	if (info->params.preamble != HDLC_PREAMBLE_PATTERN_NONE)
4222 		val |= BIT6;
4223 
4224 	switch (info->params.preamble_length)
4225 	{
4226 	case HDLC_PREAMBLE_LENGTH_16BITS: val |= BIT5; break;
4227 	case HDLC_PREAMBLE_LENGTH_32BITS: val |= BIT4; break;
4228 	case HDLC_PREAMBLE_LENGTH_64BITS: val |= BIT5 + BIT4; break;
4229 	}
4230 
4231 	if (info->params.flags & HDLC_FLAG_AUTO_CTS)
4232 		val |= BIT0;
4233 
4234 	wr_reg16(info, TCR, val);
4235 
4236 	/* TPR (transmit preamble) */
4237 
4238 	switch (info->params.preamble)
4239 	{
4240 	case HDLC_PREAMBLE_PATTERN_FLAGS: val = 0x7e; break;
4241 	case HDLC_PREAMBLE_PATTERN_ONES:  val = 0xff; break;
4242 	case HDLC_PREAMBLE_PATTERN_ZEROS: val = 0x00; break;
4243 	case HDLC_PREAMBLE_PATTERN_10:    val = 0x55; break;
4244 	case HDLC_PREAMBLE_PATTERN_01:    val = 0xaa; break;
4245 	default:                          val = 0x7e; break;
4246 	}
4247 	wr_reg8(info, TPR, (unsigned char)val);
4248 
4249 	/* RCR (rx control)
4250 	 *
4251 	 * 15..13  mode
4252 	 *         000=HDLC/SDLC
4253 	 *         001=raw bit synchronous
4254 	 *         010=asynchronous/isochronous
4255 	 *         011=monosync byte synchronous
4256 	 *         100=bisync byte synchronous
4257 	 *         101=xsync byte synchronous
4258 	 * 12..10  encoding
4259 	 * 09      CRC enable
4260 	 * 08      CRC32
4261 	 * 07..03  reserved, must be 0
4262 	 * 02      reset
4263 	 * 01      enable
4264 	 * 00      auto-DCD enable
4265 	 */
4266 	val = 0;
4267 
4268 	switch(info->params.mode) {
4269 	case MGSL_MODE_XSYNC:
4270 		val |= BIT15 + BIT13;
4271 		break;
4272 	case MGSL_MODE_MONOSYNC: val |= BIT14 + BIT13; break;
4273 	case MGSL_MODE_BISYNC:   val |= BIT15; break;
4274 	case MGSL_MODE_RAW:      val |= BIT13; break;
4275 	}
4276 
4277 	switch(info->params.encoding)
4278 	{
4279 	case HDLC_ENCODING_NRZB:          val |= BIT10; break;
4280 	case HDLC_ENCODING_NRZI_MARK:     val |= BIT11; break;
4281 	case HDLC_ENCODING_NRZI:          val |= BIT11 + BIT10; break;
4282 	case HDLC_ENCODING_BIPHASE_MARK:  val |= BIT12; break;
4283 	case HDLC_ENCODING_BIPHASE_SPACE: val |= BIT12 + BIT10; break;
4284 	case HDLC_ENCODING_BIPHASE_LEVEL: val |= BIT12 + BIT11; break;
4285 	case HDLC_ENCODING_DIFF_BIPHASE_LEVEL: val |= BIT12 + BIT11 + BIT10; break;
4286 	}
4287 
4288 	switch (info->params.crc_type & HDLC_CRC_MASK)
4289 	{
4290 	case HDLC_CRC_16_CCITT: val |= BIT9; break;
4291 	case HDLC_CRC_32_CCITT: val |= BIT9 + BIT8; break;
4292 	}
4293 
4294 	if (info->params.flags & HDLC_FLAG_AUTO_DCD)
4295 		val |= BIT0;
4296 
4297 	wr_reg16(info, RCR, val);
4298 
4299 	/* CCR (clock control)
4300 	 *
4301 	 * 07..05  tx clock source
4302 	 * 04..02  rx clock source
4303 	 * 01      auxclk enable
4304 	 * 00      BRG enable
4305 	 */
4306 	val = 0;
4307 
4308 	if (info->params.flags & HDLC_FLAG_TXC_BRG)
4309 	{
4310 		// when RxC source is DPLL, BRG generates 16X DPLL
4311 		// reference clock, so take TxC from BRG/16 to get
4312 		// transmit clock at actual data rate
4313 		if (info->params.flags & HDLC_FLAG_RXC_DPLL)
4314 			val |= BIT6 + BIT5;	/* 011, txclk = BRG/16 */
4315 		else
4316 			val |= BIT6;	/* 010, txclk = BRG */
4317 	}
4318 	else if (info->params.flags & HDLC_FLAG_TXC_DPLL)
4319 		val |= BIT7;	/* 100, txclk = DPLL Input */
4320 	else if (info->params.flags & HDLC_FLAG_TXC_RXCPIN)
4321 		val |= BIT5;	/* 001, txclk = RXC Input */
4322 
4323 	if (info->params.flags & HDLC_FLAG_RXC_BRG)
4324 		val |= BIT3;	/* 010, rxclk = BRG */
4325 	else if (info->params.flags & HDLC_FLAG_RXC_DPLL)
4326 		val |= BIT4;	/* 100, rxclk = DPLL */
4327 	else if (info->params.flags & HDLC_FLAG_RXC_TXCPIN)
4328 		val |= BIT2;	/* 001, rxclk = TXC Input */
4329 
4330 	if (info->params.clock_speed)
4331 		val |= BIT1 + BIT0;
4332 
4333 	wr_reg8(info, CCR, (unsigned char)val);
4334 
4335 	if (info->params.flags & (HDLC_FLAG_TXC_DPLL + HDLC_FLAG_RXC_DPLL))
4336 	{
4337 		// program DPLL mode
4338 		switch(info->params.encoding)
4339 		{
4340 		case HDLC_ENCODING_BIPHASE_MARK:
4341 		case HDLC_ENCODING_BIPHASE_SPACE:
4342 			val = BIT7; break;
4343 		case HDLC_ENCODING_BIPHASE_LEVEL:
4344 		case HDLC_ENCODING_DIFF_BIPHASE_LEVEL:
4345 			val = BIT7 + BIT6; break;
4346 		default: val = BIT6;	// NRZ encodings
4347 		}
4348 		wr_reg16(info, RCR, (unsigned short)(rd_reg16(info, RCR) | val));
4349 
4350 		// DPLL requires a 16X reference clock from BRG
4351 		set_rate(info, info->params.clock_speed * 16);
4352 	}
4353 	else
4354 		set_rate(info, info->params.clock_speed);
4355 
4356 	tx_set_idle(info);
4357 
4358 	msc_set_vcr(info);
4359 
4360 	/* SCR (serial control)
4361 	 *
4362 	 * 15  1=tx req on FIFO half empty
4363 	 * 14  1=rx req on FIFO half full
4364 	 * 13  tx data  IRQ enable
4365 	 * 12  tx idle  IRQ enable
4366 	 * 11  underrun IRQ enable
4367 	 * 10  rx data  IRQ enable
4368 	 * 09  rx idle  IRQ enable
4369 	 * 08  overrun  IRQ enable
4370 	 * 07  DSR      IRQ enable
4371 	 * 06  CTS      IRQ enable
4372 	 * 05  DCD      IRQ enable
4373 	 * 04  RI       IRQ enable
4374 	 * 03  reserved, must be zero
4375 	 * 02  1=txd->rxd internal loopback enable
4376 	 * 01  reserved, must be zero
4377 	 * 00  1=master IRQ enable
4378 	 */
4379 	wr_reg16(info, SCR, BIT15 + BIT14 + BIT0);
4380 
4381 	if (info->params.loopback)
4382 		enable_loopback(info);
4383 }
4384 
4385 /*
4386  *  set transmit idle mode
4387  */
4388 static void tx_set_idle(struct slgt_info *info)
4389 {
4390 	unsigned char val;
4391 	unsigned short tcr;
4392 
4393 	/* if preamble enabled (tcr[6] == 1) then tx idle size = 8 bits
4394 	 * else tcr[5:4] = tx idle size: 00 = 8 bits, 01 = 16 bits
4395 	 */
4396 	tcr = rd_reg16(info, TCR);
4397 	if (info->idle_mode & HDLC_TXIDLE_CUSTOM_16) {
4398 		/* disable preamble, set idle size to 16 bits */
4399 		tcr = (tcr & ~(BIT6 + BIT5)) | BIT4;
4400 		/* MSB of 16 bit idle specified in tx preamble register (TPR) */
4401 		wr_reg8(info, TPR, (unsigned char)((info->idle_mode >> 8) & 0xff));
4402 	} else if (!(tcr & BIT6)) {
4403 		/* preamble is disabled, set idle size to 8 bits */
4404 		tcr &= ~(BIT5 + BIT4);
4405 	}
4406 	wr_reg16(info, TCR, tcr);
4407 
4408 	if (info->idle_mode & (HDLC_TXIDLE_CUSTOM_8 | HDLC_TXIDLE_CUSTOM_16)) {
4409 		/* LSB of custom tx idle specified in tx idle register */
4410 		val = (unsigned char)(info->idle_mode & 0xff);
4411 	} else {
4412 		/* standard 8 bit idle patterns */
4413 		switch(info->idle_mode)
4414 		{
4415 		case HDLC_TXIDLE_FLAGS:          val = 0x7e; break;
4416 		case HDLC_TXIDLE_ALT_ZEROS_ONES:
4417 		case HDLC_TXIDLE_ALT_MARK_SPACE: val = 0xaa; break;
4418 		case HDLC_TXIDLE_ZEROS:
4419 		case HDLC_TXIDLE_SPACE:          val = 0x00; break;
4420 		default:                         val = 0xff;
4421 		}
4422 	}
4423 
4424 	wr_reg8(info, TIR, val);
4425 }
4426 
4427 /*
4428  * get state of V24 status (input) signals
4429  */
4430 static void get_signals(struct slgt_info *info)
4431 {
4432 	unsigned short status = rd_reg16(info, SSR);
4433 
4434 	/* clear all serial signals except RTS and DTR */
4435 	info->signals &= SerialSignal_RTS | SerialSignal_DTR;
4436 
4437 	if (status & BIT3)
4438 		info->signals |= SerialSignal_DSR;
4439 	if (status & BIT2)
4440 		info->signals |= SerialSignal_CTS;
4441 	if (status & BIT1)
4442 		info->signals |= SerialSignal_DCD;
4443 	if (status & BIT0)
4444 		info->signals |= SerialSignal_RI;
4445 }
4446 
4447 /*
4448  * set V.24 Control Register based on current configuration
4449  */
4450 static void msc_set_vcr(struct slgt_info *info)
4451 {
4452 	unsigned char val = 0;
4453 
4454 	/* VCR (V.24 control)
4455 	 *
4456 	 * 07..04  serial IF select
4457 	 * 03      DTR
4458 	 * 02      RTS
4459 	 * 01      LL
4460 	 * 00      RL
4461 	 */
4462 
4463 	switch(info->if_mode & MGSL_INTERFACE_MASK)
4464 	{
4465 	case MGSL_INTERFACE_RS232:
4466 		val |= BIT5; /* 0010 */
4467 		break;
4468 	case MGSL_INTERFACE_V35:
4469 		val |= BIT7 + BIT6 + BIT5; /* 1110 */
4470 		break;
4471 	case MGSL_INTERFACE_RS422:
4472 		val |= BIT6; /* 0100 */
4473 		break;
4474 	}
4475 
4476 	if (info->if_mode & MGSL_INTERFACE_MSB_FIRST)
4477 		val |= BIT4;
4478 	if (info->signals & SerialSignal_DTR)
4479 		val |= BIT3;
4480 	if (info->signals & SerialSignal_RTS)
4481 		val |= BIT2;
4482 	if (info->if_mode & MGSL_INTERFACE_LL)
4483 		val |= BIT1;
4484 	if (info->if_mode & MGSL_INTERFACE_RL)
4485 		val |= BIT0;
4486 	wr_reg8(info, VCR, val);
4487 }
4488 
4489 /*
4490  * set state of V24 control (output) signals
4491  */
4492 static void set_signals(struct slgt_info *info)
4493 {
4494 	unsigned char val = rd_reg8(info, VCR);
4495 	if (info->signals & SerialSignal_DTR)
4496 		val |= BIT3;
4497 	else
4498 		val &= ~BIT3;
4499 	if (info->signals & SerialSignal_RTS)
4500 		val |= BIT2;
4501 	else
4502 		val &= ~BIT2;
4503 	wr_reg8(info, VCR, val);
4504 }
4505 
4506 /*
4507  * free range of receive DMA buffers (i to last)
4508  */
4509 static void free_rbufs(struct slgt_info *info, unsigned int i, unsigned int last)
4510 {
4511 	int done = 0;
4512 
4513 	while(!done) {
4514 		/* reset current buffer for reuse */
4515 		info->rbufs[i].status = 0;
4516 		set_desc_count(info->rbufs[i], info->rbuf_fill_level);
4517 		if (i == last)
4518 			done = 1;
4519 		if (++i == info->rbuf_count)
4520 			i = 0;
4521 	}
4522 	info->rbuf_current = i;
4523 }
4524 
4525 /*
4526  * mark all receive DMA buffers as free
4527  */
4528 static void reset_rbufs(struct slgt_info *info)
4529 {
4530 	free_rbufs(info, 0, info->rbuf_count - 1);
4531 	info->rbuf_fill_index = 0;
4532 	info->rbuf_fill_count = 0;
4533 }
4534 
4535 /*
4536  * pass receive HDLC frame to upper layer
4537  *
4538  * return true if frame available, otherwise false
4539  */
4540 static bool rx_get_frame(struct slgt_info *info)
4541 {
4542 	unsigned int start, end;
4543 	unsigned short status;
4544 	unsigned int framesize = 0;
4545 	unsigned long flags;
4546 	struct tty_struct *tty = info->port.tty;
4547 	unsigned char addr_field = 0xff;
4548 	unsigned int crc_size = 0;
4549 
4550 	switch (info->params.crc_type & HDLC_CRC_MASK) {
4551 	case HDLC_CRC_16_CCITT: crc_size = 2; break;
4552 	case HDLC_CRC_32_CCITT: crc_size = 4; break;
4553 	}
4554 
4555 check_again:
4556 
4557 	framesize = 0;
4558 	addr_field = 0xff;
4559 	start = end = info->rbuf_current;
4560 
4561 	for (;;) {
4562 		if (!desc_complete(info->rbufs[end]))
4563 			goto cleanup;
4564 
4565 		if (framesize == 0 && info->params.addr_filter != 0xff)
4566 			addr_field = info->rbufs[end].buf[0];
4567 
4568 		framesize += desc_count(info->rbufs[end]);
4569 
4570 		if (desc_eof(info->rbufs[end]))
4571 			break;
4572 
4573 		if (++end == info->rbuf_count)
4574 			end = 0;
4575 
4576 		if (end == info->rbuf_current) {
4577 			if (info->rx_enabled){
4578 				spin_lock_irqsave(&info->lock,flags);
4579 				rx_start(info);
4580 				spin_unlock_irqrestore(&info->lock,flags);
4581 			}
4582 			goto cleanup;
4583 		}
4584 	}
4585 
4586 	/* status
4587 	 *
4588 	 * 15      buffer complete
4589 	 * 14..06  reserved
4590 	 * 05..04  residue
4591 	 * 02      eof (end of frame)
4592 	 * 01      CRC error
4593 	 * 00      abort
4594 	 */
4595 	status = desc_status(info->rbufs[end]);
4596 
4597 	/* ignore CRC bit if not using CRC (bit is undefined) */
4598 	if ((info->params.crc_type & HDLC_CRC_MASK) == HDLC_CRC_NONE)
4599 		status &= ~BIT1;
4600 
4601 	if (framesize == 0 ||
4602 		 (addr_field != 0xff && addr_field != info->params.addr_filter)) {
4603 		free_rbufs(info, start, end);
4604 		goto check_again;
4605 	}
4606 
4607 	if (framesize < (2 + crc_size) || status & BIT0) {
4608 		info->icount.rxshort++;
4609 		framesize = 0;
4610 	} else if (status & BIT1) {
4611 		info->icount.rxcrc++;
4612 		if (!(info->params.crc_type & HDLC_CRC_RETURN_EX))
4613 			framesize = 0;
4614 	}
4615 
4616 #if SYNCLINK_GENERIC_HDLC
4617 	if (framesize == 0) {
4618 		info->netdev->stats.rx_errors++;
4619 		info->netdev->stats.rx_frame_errors++;
4620 	}
4621 #endif
4622 
4623 	DBGBH(("%s rx frame status=%04X size=%d\n",
4624 		info->device_name, status, framesize));
4625 	DBGDATA(info, info->rbufs[start].buf, min_t(int, framesize, info->rbuf_fill_level), "rx");
4626 
4627 	if (framesize) {
4628 		if (!(info->params.crc_type & HDLC_CRC_RETURN_EX)) {
4629 			framesize -= crc_size;
4630 			crc_size = 0;
4631 		}
4632 
4633 		if (framesize > info->max_frame_size + crc_size)
4634 			info->icount.rxlong++;
4635 		else {
4636 			/* copy dma buffer(s) to contiguous temp buffer */
4637 			int copy_count = framesize;
4638 			int i = start;
4639 			unsigned char *p = info->tmp_rbuf;
4640 			info->tmp_rbuf_count = framesize;
4641 
4642 			info->icount.rxok++;
4643 
4644 			while(copy_count) {
4645 				int partial_count = min_t(int, copy_count, info->rbuf_fill_level);
4646 				memcpy(p, info->rbufs[i].buf, partial_count);
4647 				p += partial_count;
4648 				copy_count -= partial_count;
4649 				if (++i == info->rbuf_count)
4650 					i = 0;
4651 			}
4652 
4653 			if (info->params.crc_type & HDLC_CRC_RETURN_EX) {
4654 				*p = (status & BIT1) ? RX_CRC_ERROR : RX_OK;
4655 				framesize++;
4656 			}
4657 
4658 #if SYNCLINK_GENERIC_HDLC
4659 			if (info->netcount)
4660 				hdlcdev_rx(info,info->tmp_rbuf, framesize);
4661 			else
4662 #endif
4663 				ldisc_receive_buf(tty, info->tmp_rbuf, info->flag_buf, framesize);
4664 		}
4665 	}
4666 	free_rbufs(info, start, end);
4667 	return true;
4668 
4669 cleanup:
4670 	return false;
4671 }
4672 
4673 /*
4674  * pass receive buffer (RAW synchronous mode) to tty layer
4675  * return true if buffer available, otherwise false
4676  */
4677 static bool rx_get_buf(struct slgt_info *info)
4678 {
4679 	unsigned int i = info->rbuf_current;
4680 	unsigned int count;
4681 
4682 	if (!desc_complete(info->rbufs[i]))
4683 		return false;
4684 	count = desc_count(info->rbufs[i]);
4685 	switch(info->params.mode) {
4686 	case MGSL_MODE_MONOSYNC:
4687 	case MGSL_MODE_BISYNC:
4688 	case MGSL_MODE_XSYNC:
4689 		/* ignore residue in byte synchronous modes */
4690 		if (desc_residue(info->rbufs[i]))
4691 			count--;
4692 		break;
4693 	}
4694 	DBGDATA(info, info->rbufs[i].buf, count, "rx");
4695 	DBGINFO(("rx_get_buf size=%d\n", count));
4696 	if (count)
4697 		ldisc_receive_buf(info->port.tty, info->rbufs[i].buf,
4698 				  info->flag_buf, count);
4699 	free_rbufs(info, i, i);
4700 	return true;
4701 }
4702 
4703 static void reset_tbufs(struct slgt_info *info)
4704 {
4705 	unsigned int i;
4706 	info->tbuf_current = 0;
4707 	for (i=0 ; i < info->tbuf_count ; i++) {
4708 		info->tbufs[i].status = 0;
4709 		info->tbufs[i].count  = 0;
4710 	}
4711 }
4712 
4713 /*
4714  * return number of free transmit DMA buffers
4715  */
4716 static unsigned int free_tbuf_count(struct slgt_info *info)
4717 {
4718 	unsigned int count = 0;
4719 	unsigned int i = info->tbuf_current;
4720 
4721 	do
4722 	{
4723 		if (desc_count(info->tbufs[i]))
4724 			break; /* buffer in use */
4725 		++count;
4726 		if (++i == info->tbuf_count)
4727 			i=0;
4728 	} while (i != info->tbuf_current);
4729 
4730 	/* if tx DMA active, last zero count buffer is in use */
4731 	if (count && (rd_reg32(info, TDCSR) & BIT0))
4732 		--count;
4733 
4734 	return count;
4735 }
4736 
4737 /*
4738  * return number of bytes in unsent transmit DMA buffers
4739  * and the serial controller tx FIFO
4740  */
4741 static unsigned int tbuf_bytes(struct slgt_info *info)
4742 {
4743 	unsigned int total_count = 0;
4744 	unsigned int i = info->tbuf_current;
4745 	unsigned int reg_value;
4746 	unsigned int count;
4747 	unsigned int active_buf_count = 0;
4748 
4749 	/*
4750 	 * Add descriptor counts for all tx DMA buffers.
4751 	 * If count is zero (cleared by DMA controller after read),
4752 	 * the buffer is complete or is actively being read from.
4753 	 *
4754 	 * Record buf_count of last buffer with zero count starting
4755 	 * from current ring position. buf_count is mirror
4756 	 * copy of count and is not cleared by serial controller.
4757 	 * If DMA controller is active, that buffer is actively
4758 	 * being read so add to total.
4759 	 */
4760 	do {
4761 		count = desc_count(info->tbufs[i]);
4762 		if (count)
4763 			total_count += count;
4764 		else if (!total_count)
4765 			active_buf_count = info->tbufs[i].buf_count;
4766 		if (++i == info->tbuf_count)
4767 			i = 0;
4768 	} while (i != info->tbuf_current);
4769 
4770 	/* read tx DMA status register */
4771 	reg_value = rd_reg32(info, TDCSR);
4772 
4773 	/* if tx DMA active, last zero count buffer is in use */
4774 	if (reg_value & BIT0)
4775 		total_count += active_buf_count;
4776 
4777 	/* add tx FIFO count = reg_value[15..8] */
4778 	total_count += (reg_value >> 8) & 0xff;
4779 
4780 	/* if transmitter active add one byte for shift register */
4781 	if (info->tx_active)
4782 		total_count++;
4783 
4784 	return total_count;
4785 }
4786 
4787 /*
4788  * load data into transmit DMA buffer ring and start transmitter if needed
4789  * return true if data accepted, otherwise false (buffers full)
4790  */
4791 static bool tx_load(struct slgt_info *info, const char *buf, unsigned int size)
4792 {
4793 	unsigned short count;
4794 	unsigned int i;
4795 	struct slgt_desc *d;
4796 
4797 	/* check required buffer space */
4798 	if (DIV_ROUND_UP(size, DMABUFSIZE) > free_tbuf_count(info))
4799 		return false;
4800 
4801 	DBGDATA(info, buf, size, "tx");
4802 
4803 	/*
4804 	 * copy data to one or more DMA buffers in circular ring
4805 	 * tbuf_start   = first buffer for this data
4806 	 * tbuf_current = next free buffer
4807 	 *
4808 	 * Copy all data before making data visible to DMA controller by
4809 	 * setting descriptor count of the first buffer.
4810 	 * This prevents an active DMA controller from reading the first DMA
4811 	 * buffers of a frame and stopping before the final buffers are filled.
4812 	 */
4813 
4814 	info->tbuf_start = i = info->tbuf_current;
4815 
4816 	while (size) {
4817 		d = &info->tbufs[i];
4818 
4819 		count = (unsigned short)((size > DMABUFSIZE) ? DMABUFSIZE : size);
4820 		memcpy(d->buf, buf, count);
4821 
4822 		size -= count;
4823 		buf  += count;
4824 
4825 		/*
4826 		 * set EOF bit for last buffer of HDLC frame or
4827 		 * for every buffer in raw mode
4828 		 */
4829 		if ((!size && info->params.mode == MGSL_MODE_HDLC) ||
4830 		    info->params.mode == MGSL_MODE_RAW)
4831 			set_desc_eof(*d, 1);
4832 		else
4833 			set_desc_eof(*d, 0);
4834 
4835 		/* set descriptor count for all but first buffer */
4836 		if (i != info->tbuf_start)
4837 			set_desc_count(*d, count);
4838 		d->buf_count = count;
4839 
4840 		if (++i == info->tbuf_count)
4841 			i = 0;
4842 	}
4843 
4844 	info->tbuf_current = i;
4845 
4846 	/* set first buffer count to make new data visible to DMA controller */
4847 	d = &info->tbufs[info->tbuf_start];
4848 	set_desc_count(*d, d->buf_count);
4849 
4850 	/* start transmitter if needed and update transmit timeout */
4851 	if (!info->tx_active)
4852 		tx_start(info);
4853 	update_tx_timer(info);
4854 
4855 	return true;
4856 }
4857 
4858 static int register_test(struct slgt_info *info)
4859 {
4860 	static unsigned short patterns[] =
4861 		{0x0000, 0xffff, 0xaaaa, 0x5555, 0x6969, 0x9696};
4862 	static unsigned int count = ARRAY_SIZE(patterns);
4863 	unsigned int i;
4864 	int rc = 0;
4865 
4866 	for (i=0 ; i < count ; i++) {
4867 		wr_reg16(info, TIR, patterns[i]);
4868 		wr_reg16(info, BDR, patterns[(i+1)%count]);
4869 		if ((rd_reg16(info, TIR) != patterns[i]) ||
4870 		    (rd_reg16(info, BDR) != patterns[(i+1)%count])) {
4871 			rc = -ENODEV;
4872 			break;
4873 		}
4874 	}
4875 	info->gpio_present = (rd_reg32(info, JCR) & BIT5) ? 1 : 0;
4876 	info->init_error = rc ? 0 : DiagStatus_AddressFailure;
4877 	return rc;
4878 }
4879 
4880 static int irq_test(struct slgt_info *info)
4881 {
4882 	unsigned long timeout;
4883 	unsigned long flags;
4884 	struct tty_struct *oldtty = info->port.tty;
4885 	u32 speed = info->params.data_rate;
4886 
4887 	info->params.data_rate = 921600;
4888 	info->port.tty = NULL;
4889 
4890 	spin_lock_irqsave(&info->lock, flags);
4891 	async_mode(info);
4892 	slgt_irq_on(info, IRQ_TXIDLE);
4893 
4894 	/* enable transmitter */
4895 	wr_reg16(info, TCR,
4896 		(unsigned short)(rd_reg16(info, TCR) | BIT1));
4897 
4898 	/* write one byte and wait for tx idle */
4899 	wr_reg16(info, TDR, 0);
4900 
4901 	/* assume failure */
4902 	info->init_error = DiagStatus_IrqFailure;
4903 	info->irq_occurred = false;
4904 
4905 	spin_unlock_irqrestore(&info->lock, flags);
4906 
4907 	timeout=100;
4908 	while(timeout-- && !info->irq_occurred)
4909 		msleep_interruptible(10);
4910 
4911 	spin_lock_irqsave(&info->lock,flags);
4912 	reset_port(info);
4913 	spin_unlock_irqrestore(&info->lock,flags);
4914 
4915 	info->params.data_rate = speed;
4916 	info->port.tty = oldtty;
4917 
4918 	info->init_error = info->irq_occurred ? 0 : DiagStatus_IrqFailure;
4919 	return info->irq_occurred ? 0 : -ENODEV;
4920 }
4921 
4922 static int loopback_test_rx(struct slgt_info *info)
4923 {
4924 	unsigned char *src, *dest;
4925 	int count;
4926 
4927 	if (desc_complete(info->rbufs[0])) {
4928 		count = desc_count(info->rbufs[0]);
4929 		src   = info->rbufs[0].buf;
4930 		dest  = info->tmp_rbuf;
4931 
4932 		for( ; count ; count-=2, src+=2) {
4933 			/* src=data byte (src+1)=status byte */
4934 			if (!(*(src+1) & (BIT9 + BIT8))) {
4935 				*dest = *src;
4936 				dest++;
4937 				info->tmp_rbuf_count++;
4938 			}
4939 		}
4940 		DBGDATA(info, info->tmp_rbuf, info->tmp_rbuf_count, "rx");
4941 		return 1;
4942 	}
4943 	return 0;
4944 }
4945 
4946 static int loopback_test(struct slgt_info *info)
4947 {
4948 #define TESTFRAMESIZE 20
4949 
4950 	unsigned long timeout;
4951 	u16 count;
4952 	unsigned char buf[TESTFRAMESIZE];
4953 	int rc = -ENODEV;
4954 	unsigned long flags;
4955 
4956 	struct tty_struct *oldtty = info->port.tty;
4957 	MGSL_PARAMS params;
4958 
4959 	memcpy(&params, &info->params, sizeof(params));
4960 
4961 	info->params.mode = MGSL_MODE_ASYNC;
4962 	info->params.data_rate = 921600;
4963 	info->params.loopback = 1;
4964 	info->port.tty = NULL;
4965 
4966 	/* build and send transmit frame */
4967 	for (count = 0; count < TESTFRAMESIZE; ++count)
4968 		buf[count] = (unsigned char)count;
4969 
4970 	info->tmp_rbuf_count = 0;
4971 	memset(info->tmp_rbuf, 0, TESTFRAMESIZE);
4972 
4973 	/* program hardware for HDLC and enabled receiver */
4974 	spin_lock_irqsave(&info->lock,flags);
4975 	async_mode(info);
4976 	rx_start(info);
4977 	tx_load(info, buf, count);
4978 	spin_unlock_irqrestore(&info->lock, flags);
4979 
4980 	/* wait for receive complete */
4981 	for (timeout = 100; timeout; --timeout) {
4982 		msleep_interruptible(10);
4983 		if (loopback_test_rx(info)) {
4984 			rc = 0;
4985 			break;
4986 		}
4987 	}
4988 
4989 	/* verify received frame length and contents */
4990 	if (!rc && (info->tmp_rbuf_count != count ||
4991 		  memcmp(buf, info->tmp_rbuf, count))) {
4992 		rc = -ENODEV;
4993 	}
4994 
4995 	spin_lock_irqsave(&info->lock,flags);
4996 	reset_adapter(info);
4997 	spin_unlock_irqrestore(&info->lock,flags);
4998 
4999 	memcpy(&info->params, &params, sizeof(info->params));
5000 	info->port.tty = oldtty;
5001 
5002 	info->init_error = rc ? DiagStatus_DmaFailure : 0;
5003 	return rc;
5004 }
5005 
5006 static int adapter_test(struct slgt_info *info)
5007 {
5008 	DBGINFO(("testing %s\n", info->device_name));
5009 	if (register_test(info) < 0) {
5010 		printk("register test failure %s addr=%08X\n",
5011 			info->device_name, info->phys_reg_addr);
5012 	} else if (irq_test(info) < 0) {
5013 		printk("IRQ test failure %s IRQ=%d\n",
5014 			info->device_name, info->irq_level);
5015 	} else if (loopback_test(info) < 0) {
5016 		printk("loopback test failure %s\n", info->device_name);
5017 	}
5018 	return info->init_error;
5019 }
5020 
5021 /*
5022  * transmit timeout handler
5023  */
5024 static void tx_timeout(struct timer_list *t)
5025 {
5026 	struct slgt_info *info = from_timer(info, t, tx_timer);
5027 	unsigned long flags;
5028 
5029 	DBGINFO(("%s tx_timeout\n", info->device_name));
5030 	if(info->tx_active && info->params.mode == MGSL_MODE_HDLC) {
5031 		info->icount.txtimeout++;
5032 	}
5033 	spin_lock_irqsave(&info->lock,flags);
5034 	tx_stop(info);
5035 	spin_unlock_irqrestore(&info->lock,flags);
5036 
5037 #if SYNCLINK_GENERIC_HDLC
5038 	if (info->netcount)
5039 		hdlcdev_tx_done(info);
5040 	else
5041 #endif
5042 		bh_transmit(info);
5043 }
5044 
5045 /*
5046  * receive buffer polling timer
5047  */
5048 static void rx_timeout(struct timer_list *t)
5049 {
5050 	struct slgt_info *info = from_timer(info, t, rx_timer);
5051 	unsigned long flags;
5052 
5053 	DBGINFO(("%s rx_timeout\n", info->device_name));
5054 	spin_lock_irqsave(&info->lock, flags);
5055 	info->pending_bh |= BH_RECEIVE;
5056 	spin_unlock_irqrestore(&info->lock, flags);
5057 	bh_handler(&info->task);
5058 }
5059 
5060