xref: /openbmc/linux/drivers/tty/mxser.c (revision dd21bfa4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  *          mxser.c  -- MOXA Smartio/Industio family multiport serial driver.
4  *
5  *      Copyright (C) 1999-2006  Moxa Technologies (support@moxa.com).
6  *	Copyright (C) 2006-2008  Jiri Slaby <jirislaby@gmail.com>
7  *
8  *      This code is loosely based on the 1.8 moxa driver which is based on
9  *	Linux serial driver, written by Linus Torvalds, Theodore T'so and
10  *	others.
11  *
12  *	Fed through a cleanup, indent and remove of non 2.6 code by Alan Cox
13  *	<alan@lxorguk.ukuu.org.uk>. The original 1.8 code is available on
14  *	www.moxa.com.
15  *	- Fixed x86_64 cleanness
16  */
17 
18 #include <linux/module.h>
19 #include <linux/errno.h>
20 #include <linux/signal.h>
21 #include <linux/sched.h>
22 #include <linux/timer.h>
23 #include <linux/interrupt.h>
24 #include <linux/tty.h>
25 #include <linux/tty_flip.h>
26 #include <linux/serial.h>
27 #include <linux/serial_reg.h>
28 #include <linux/major.h>
29 #include <linux/string.h>
30 #include <linux/fcntl.h>
31 #include <linux/ptrace.h>
32 #include <linux/ioport.h>
33 #include <linux/mm.h>
34 #include <linux/delay.h>
35 #include <linux/pci.h>
36 #include <linux/bitops.h>
37 #include <linux/slab.h>
38 #include <linux/ratelimit.h>
39 
40 #include <asm/io.h>
41 #include <asm/irq.h>
42 #include <linux/uaccess.h>
43 
44 /*
45  *	Semi-public control interfaces
46  */
47 
48 /*
49  *	MOXA ioctls
50  */
51 
52 #define MOXA			0x400
53 #define MOXA_SET_OP_MODE	(MOXA + 66)
54 #define MOXA_GET_OP_MODE	(MOXA + 67)
55 
56 #define RS232_MODE		0
57 #define RS485_2WIRE_MODE	1
58 #define RS422_MODE		2
59 #define RS485_4WIRE_MODE	3
60 #define OP_MODE_MASK		3
61 
62 /* --------------------------------------------------- */
63 
64 /*
65  * Follow just what Moxa Must chip defines.
66  *
67  * When LCR register (offset 0x03) is written the following value, the Must chip
68  * will enter enhanced mode. And a write to EFR (offset 0x02) bit 6,7 will
69  * change bank.
70  */
71 #define MOXA_MUST_ENTER_ENHANCED	0xBF
72 
73 /* when enhanced mode is enabled, access to general bank register */
74 #define MOXA_MUST_GDL_REGISTER		0x07
75 #define MOXA_MUST_GDL_MASK		0x7F
76 #define MOXA_MUST_GDL_HAS_BAD_DATA	0x80
77 
78 #define MOXA_MUST_LSR_RERR		0x80	/* error in receive FIFO */
79 /* enhanced register bank select and enhanced mode setting register */
80 /* This works only when LCR register equals to 0xBF */
81 #define MOXA_MUST_EFR_REGISTER		0x02
82 #define MOXA_MUST_EFR_EFRB_ENABLE	0x10 /* enhanced mode enable */
83 /* enhanced register bank set 0, 1, 2 */
84 #define MOXA_MUST_EFR_BANK0		0x00
85 #define MOXA_MUST_EFR_BANK1		0x40
86 #define MOXA_MUST_EFR_BANK2		0x80
87 #define MOXA_MUST_EFR_BANK3		0xC0
88 #define MOXA_MUST_EFR_BANK_MASK		0xC0
89 
90 /* set XON1 value register, when LCR=0xBF and change to bank0 */
91 #define MOXA_MUST_XON1_REGISTER		0x04
92 
93 /* set XON2 value register, when LCR=0xBF and change to bank0 */
94 #define MOXA_MUST_XON2_REGISTER		0x05
95 
96 /* set XOFF1 value register, when LCR=0xBF and change to bank0 */
97 #define MOXA_MUST_XOFF1_REGISTER	0x06
98 
99 /* set XOFF2 value register, when LCR=0xBF and change to bank0 */
100 #define MOXA_MUST_XOFF2_REGISTER	0x07
101 
102 #define MOXA_MUST_RBRTL_REGISTER	0x04
103 #define MOXA_MUST_RBRTH_REGISTER	0x05
104 #define MOXA_MUST_RBRTI_REGISTER	0x06
105 #define MOXA_MUST_THRTL_REGISTER	0x07
106 #define MOXA_MUST_ENUM_REGISTER		0x04
107 #define MOXA_MUST_HWID_REGISTER		0x05
108 #define MOXA_MUST_ECR_REGISTER		0x06
109 #define MOXA_MUST_CSR_REGISTER		0x07
110 
111 #define MOXA_MUST_FCR_GDA_MODE_ENABLE	0x20 /* good data mode enable */
112 #define MOXA_MUST_FCR_GDA_ONLY_ENABLE	0x10 /* only good data put into RxFIFO */
113 
114 #define MOXA_MUST_IER_ECTSI		0x80 /* enable CTS interrupt */
115 #define MOXA_MUST_IER_ERTSI		0x40 /* enable RTS interrupt */
116 #define MOXA_MUST_IER_XINT		0x20 /* enable Xon/Xoff interrupt */
117 #define MOXA_MUST_IER_EGDAI		0x10 /* enable GDA interrupt */
118 
119 #define MOXA_MUST_RECV_ISR		(UART_IER_RDI | MOXA_MUST_IER_EGDAI)
120 
121 /* GDA interrupt pending */
122 #define MOXA_MUST_IIR_GDA		0x1C
123 #define MOXA_MUST_IIR_RDA		0x04
124 #define MOXA_MUST_IIR_RTO		0x0C
125 #define MOXA_MUST_IIR_LSR		0x06
126 
127 /* received Xon/Xoff or specical interrupt pending */
128 #define MOXA_MUST_IIR_XSC		0x10
129 
130 /* RTS/CTS change state interrupt pending */
131 #define MOXA_MUST_IIR_RTSCTS		0x20
132 #define MOXA_MUST_IIR_MASK		0x3E
133 
134 #define MOXA_MUST_MCR_XON_FLAG		0x40
135 #define MOXA_MUST_MCR_XON_ANY		0x80
136 #define MOXA_MUST_MCR_TX_XON		0x08
137 
138 #define MOXA_MUST_EFR_SF_MASK		0x0F /* software flow control on chip mask value */
139 #define MOXA_MUST_EFR_SF_TX1		0x08 /* send Xon1/Xoff1 */
140 #define MOXA_MUST_EFR_SF_TX2		0x04 /* send Xon2/Xoff2 */
141 #define MOXA_MUST_EFR_SF_TX12		0x0C /* send Xon1,Xon2/Xoff1,Xoff2 */
142 #define MOXA_MUST_EFR_SF_TX_NO		0x00 /* don't send Xon/Xoff */
143 #define MOXA_MUST_EFR_SF_TX_MASK	0x0C /* Tx software flow control mask */
144 #define MOXA_MUST_EFR_SF_RX_NO		0x00 /* don't receive Xon/Xoff */
145 #define MOXA_MUST_EFR_SF_RX1		0x02 /* receive Xon1/Xoff1 */
146 #define MOXA_MUST_EFR_SF_RX2		0x01 /* receive Xon2/Xoff2 */
147 #define MOXA_MUST_EFR_SF_RX12		0x03 /* receive Xon1,Xon2/Xoff1,Xoff2 */
148 #define MOXA_MUST_EFR_SF_RX_MASK	0x03 /* Rx software flow control mask */
149 
150 #define	MXSERMAJOR	 174
151 
152 #define MXSER_BOARDS		4	/* Max. boards */
153 #define MXSER_PORTS_PER_BOARD	8	/* Max. ports per board */
154 #define MXSER_PORTS		(MXSER_BOARDS * MXSER_PORTS_PER_BOARD)
155 #define MXSER_ISR_PASS_LIMIT	100
156 
157 #define WAKEUP_CHARS		256
158 
159 #define MXSER_BAUD_BASE		921600
160 #define MXSER_CUSTOM_DIVISOR	(MXSER_BAUD_BASE * 16)
161 
162 #define PCI_DEVICE_ID_MOXA_RC7000	0x0001
163 #define PCI_DEVICE_ID_MOXA_CP102	0x1020
164 #define PCI_DEVICE_ID_MOXA_CP102UL	0x1021
165 #define PCI_DEVICE_ID_MOXA_CP102U	0x1022
166 #define PCI_DEVICE_ID_MOXA_CP102UF	0x1023
167 #define PCI_DEVICE_ID_MOXA_C104		0x1040
168 #define PCI_DEVICE_ID_MOXA_CP104U	0x1041
169 #define PCI_DEVICE_ID_MOXA_CP104JU	0x1042
170 #define PCI_DEVICE_ID_MOXA_CP104EL	0x1043
171 #define PCI_DEVICE_ID_MOXA_POS104UL	0x1044
172 #define PCI_DEVICE_ID_MOXA_CB108	0x1080
173 #define PCI_DEVICE_ID_MOXA_CP112UL	0x1120
174 #define PCI_DEVICE_ID_MOXA_CT114	0x1140
175 #define PCI_DEVICE_ID_MOXA_CP114	0x1141
176 #define PCI_DEVICE_ID_MOXA_CB114	0x1142
177 #define PCI_DEVICE_ID_MOXA_CP114UL	0x1143
178 #define PCI_DEVICE_ID_MOXA_CP118U	0x1180
179 #define PCI_DEVICE_ID_MOXA_CP118EL	0x1181
180 #define PCI_DEVICE_ID_MOXA_CP132	0x1320
181 #define PCI_DEVICE_ID_MOXA_CP132U	0x1321
182 #define PCI_DEVICE_ID_MOXA_CP134U	0x1340
183 #define PCI_DEVICE_ID_MOXA_CB134I	0x1341
184 #define PCI_DEVICE_ID_MOXA_CP138U	0x1380
185 #define PCI_DEVICE_ID_MOXA_C168		0x1680
186 #define PCI_DEVICE_ID_MOXA_CP168U	0x1681
187 #define PCI_DEVICE_ID_MOXA_CP168EL	0x1682
188 
189 #define MXSER_NPORTS(ddata)		((ddata) & 0xffU)
190 #define MXSER_HIGHBAUD			0x0100
191 
192 enum mxser_must_hwid {
193 	MOXA_OTHER_UART		= 0x00,
194 	MOXA_MUST_MU150_HWID	= 0x01,
195 	MOXA_MUST_MU860_HWID	= 0x02,
196 };
197 
198 static const struct {
199 	u8 type;
200 	u8 fifo_size;
201 	u8 rx_high_water;
202 	u8 rx_low_water;
203 	speed_t max_baud;
204 } Gpci_uart_info[] = {
205 	{ MOXA_OTHER_UART,	 16, 14,  1, 921600 },
206 	{ MOXA_MUST_MU150_HWID,	 64, 48, 16, 230400 },
207 	{ MOXA_MUST_MU860_HWID, 128, 96, 32, 921600 }
208 };
209 #define UART_INFO_NUM	ARRAY_SIZE(Gpci_uart_info)
210 
211 
212 /* driver_data correspond to the lines in the structure above
213    see also ISA probe function before you change something */
214 static const struct pci_device_id mxser_pcibrds[] = {
215 	{ PCI_DEVICE_DATA(MOXA, C168,		8) },
216 	{ PCI_DEVICE_DATA(MOXA, C104,		4) },
217 	{ PCI_DEVICE_DATA(MOXA, CP132,		2) },
218 	{ PCI_DEVICE_DATA(MOXA, CP114,		4) },
219 	{ PCI_DEVICE_DATA(MOXA, CT114,		4) },
220 	{ PCI_DEVICE_DATA(MOXA, CP102,		2 | MXSER_HIGHBAUD) },
221 	{ PCI_DEVICE_DATA(MOXA, CP104U,		4) },
222 	{ PCI_DEVICE_DATA(MOXA, CP168U,		8) },
223 	{ PCI_DEVICE_DATA(MOXA, CP132U,		2) },
224 	{ PCI_DEVICE_DATA(MOXA, CP134U,		4) },
225 	{ PCI_DEVICE_DATA(MOXA, CP104JU,	4) },
226 	{ PCI_DEVICE_DATA(MOXA, RC7000,		8) }, /* RC7000 */
227 	{ PCI_DEVICE_DATA(MOXA, CP118U,		8) },
228 	{ PCI_DEVICE_DATA(MOXA, CP102UL,	2) },
229 	{ PCI_DEVICE_DATA(MOXA, CP102U,		2) },
230 	{ PCI_DEVICE_DATA(MOXA, CP118EL,	8) },
231 	{ PCI_DEVICE_DATA(MOXA, CP168EL,	8) },
232 	{ PCI_DEVICE_DATA(MOXA, CP104EL,	4) },
233 	{ PCI_DEVICE_DATA(MOXA, CB108,		8) },
234 	{ PCI_DEVICE_DATA(MOXA, CB114,		4) },
235 	{ PCI_DEVICE_DATA(MOXA, CB134I,		4) },
236 	{ PCI_DEVICE_DATA(MOXA, CP138U,		8) },
237 	{ PCI_DEVICE_DATA(MOXA, POS104UL,	4) },
238 	{ PCI_DEVICE_DATA(MOXA, CP114UL,	4) },
239 	{ PCI_DEVICE_DATA(MOXA, CP102UF,	2) },
240 	{ PCI_DEVICE_DATA(MOXA, CP112UL,	2) },
241 	{ }
242 };
243 MODULE_DEVICE_TABLE(pci, mxser_pcibrds);
244 
245 static int ttymajor = MXSERMAJOR;
246 
247 /* Variables for insmod */
248 
249 MODULE_AUTHOR("Casper Yang");
250 MODULE_DESCRIPTION("MOXA Smartio/Industio Family Multiport Board Device Driver");
251 module_param(ttymajor, int, 0);
252 MODULE_LICENSE("GPL");
253 
254 struct mxser_board;
255 
256 struct mxser_port {
257 	struct tty_port port;
258 	struct mxser_board *board;
259 
260 	unsigned long ioaddr;
261 	unsigned long opmode_ioaddr;
262 
263 	u8 rx_high_water;
264 	u8 rx_low_water;
265 	int type;		/* UART type */
266 
267 	unsigned char x_char;	/* xon/xoff character */
268 	u8 IER;			/* Interrupt Enable Register */
269 	u8 MCR;			/* Modem control register */
270 	u8 FCR;			/* FIFO control register */
271 
272 	struct async_icount icount; /* kernel counters for 4 input interrupts */
273 	unsigned int timeout;
274 
275 	u8 read_status_mask;
276 	u8 ignore_status_mask;
277 	u8 xmit_fifo_size;
278 	unsigned int xmit_head;
279 	unsigned int xmit_tail;
280 	unsigned int xmit_cnt;
281 
282 	spinlock_t slock;
283 };
284 
285 struct mxser_board {
286 	unsigned int idx;
287 	unsigned short nports;
288 	int irq;
289 	unsigned long vector;
290 
291 	enum mxser_must_hwid must_hwid;
292 	speed_t max_baud;
293 
294 	struct mxser_port ports[];
295 };
296 
297 static DECLARE_BITMAP(mxser_boards, MXSER_BOARDS);
298 static struct tty_driver *mxvar_sdriver;
299 
300 static u8 __mxser_must_set_EFR(unsigned long baseio, u8 clear, u8 set,
301 		bool restore_LCR)
302 {
303 	u8 oldlcr, efr;
304 
305 	oldlcr = inb(baseio + UART_LCR);
306 	outb(MOXA_MUST_ENTER_ENHANCED, baseio + UART_LCR);
307 
308 	efr = inb(baseio + MOXA_MUST_EFR_REGISTER);
309 	efr &= ~clear;
310 	efr |= set;
311 
312 	outb(efr, baseio + MOXA_MUST_EFR_REGISTER);
313 
314 	if (restore_LCR)
315 		outb(oldlcr, baseio + UART_LCR);
316 
317 	return oldlcr;
318 }
319 
320 static u8 mxser_must_select_bank(unsigned long baseio, u8 bank)
321 {
322 	return __mxser_must_set_EFR(baseio, MOXA_MUST_EFR_BANK_MASK, bank,
323 			false);
324 }
325 
326 static void mxser_set_must_xon1_value(unsigned long baseio, u8 value)
327 {
328 	u8 oldlcr = mxser_must_select_bank(baseio, MOXA_MUST_EFR_BANK0);
329 	outb(value, baseio + MOXA_MUST_XON1_REGISTER);
330 	outb(oldlcr, baseio + UART_LCR);
331 }
332 
333 static void mxser_set_must_xoff1_value(unsigned long baseio, u8 value)
334 {
335 	u8 oldlcr = mxser_must_select_bank(baseio, MOXA_MUST_EFR_BANK0);
336 	outb(value, baseio + MOXA_MUST_XOFF1_REGISTER);
337 	outb(oldlcr, baseio + UART_LCR);
338 }
339 
340 static void mxser_set_must_fifo_value(struct mxser_port *info)
341 {
342 	u8 oldlcr = mxser_must_select_bank(info->ioaddr, MOXA_MUST_EFR_BANK1);
343 	outb(info->rx_high_water, info->ioaddr + MOXA_MUST_RBRTH_REGISTER);
344 	outb(info->rx_high_water, info->ioaddr + MOXA_MUST_RBRTI_REGISTER);
345 	outb(info->rx_low_water, info->ioaddr + MOXA_MUST_RBRTL_REGISTER);
346 	outb(oldlcr, info->ioaddr + UART_LCR);
347 }
348 
349 static void mxser_set_must_enum_value(unsigned long baseio, u8 value)
350 {
351 	u8 oldlcr = mxser_must_select_bank(baseio, MOXA_MUST_EFR_BANK2);
352 	outb(value, baseio + MOXA_MUST_ENUM_REGISTER);
353 	outb(oldlcr, baseio + UART_LCR);
354 }
355 
356 static u8 mxser_get_must_hardware_id(unsigned long baseio)
357 {
358 	u8 oldlcr = mxser_must_select_bank(baseio, MOXA_MUST_EFR_BANK2);
359 	u8 id = inb(baseio + MOXA_MUST_HWID_REGISTER);
360 	outb(oldlcr, baseio + UART_LCR);
361 
362 	return id;
363 }
364 
365 static void mxser_must_set_EFR(unsigned long baseio, u8 clear, u8 set)
366 {
367 	__mxser_must_set_EFR(baseio, clear, set, true);
368 }
369 
370 static void mxser_must_set_enhance_mode(unsigned long baseio, bool enable)
371 {
372 	mxser_must_set_EFR(baseio,
373 			enable ? 0 : MOXA_MUST_EFR_EFRB_ENABLE,
374 			enable ? MOXA_MUST_EFR_EFRB_ENABLE : 0);
375 }
376 
377 static void mxser_must_no_sw_flow_control(unsigned long baseio)
378 {
379 	mxser_must_set_EFR(baseio, MOXA_MUST_EFR_SF_MASK, 0);
380 }
381 
382 static void mxser_must_set_tx_sw_flow_control(unsigned long baseio, bool enable)
383 {
384 	mxser_must_set_EFR(baseio, MOXA_MUST_EFR_SF_TX_MASK,
385 			enable ? MOXA_MUST_EFR_SF_TX1 : 0);
386 }
387 
388 static void mxser_must_set_rx_sw_flow_control(unsigned long baseio, bool enable)
389 {
390 	mxser_must_set_EFR(baseio, MOXA_MUST_EFR_SF_RX_MASK,
391 			enable ? MOXA_MUST_EFR_SF_RX1 : 0);
392 }
393 
394 static enum mxser_must_hwid mxser_must_get_hwid(unsigned long io)
395 {
396 	u8 oldmcr, hwid;
397 	int i;
398 
399 	outb(0, io + UART_LCR);
400 	mxser_must_set_enhance_mode(io, false);
401 	oldmcr = inb(io + UART_MCR);
402 	outb(0, io + UART_MCR);
403 	mxser_set_must_xon1_value(io, 0x11);
404 	if ((hwid = inb(io + UART_MCR)) != 0) {
405 		outb(oldmcr, io + UART_MCR);
406 		return MOXA_OTHER_UART;
407 	}
408 
409 	hwid = mxser_get_must_hardware_id(io);
410 	for (i = 1; i < UART_INFO_NUM; i++) /* 0 = OTHER_UART */
411 		if (hwid == Gpci_uart_info[i].type)
412 			return hwid;
413 
414 	return MOXA_OTHER_UART;
415 }
416 
417 static bool mxser_16550A_or_MUST(struct mxser_port *info)
418 {
419 	return info->type == PORT_16550A || info->board->must_hwid;
420 }
421 
422 static void mxser_process_txrx_fifo(struct mxser_port *info)
423 {
424 	unsigned int i;
425 
426 	if (info->type == PORT_16450 || info->type == PORT_8250) {
427 		info->rx_high_water = 1;
428 		info->rx_low_water = 1;
429 		info->xmit_fifo_size = 1;
430 		return;
431 	}
432 
433 	for (i = 0; i < UART_INFO_NUM; i++)
434 		if (info->board->must_hwid == Gpci_uart_info[i].type) {
435 			info->rx_low_water = Gpci_uart_info[i].rx_low_water;
436 			info->rx_high_water = Gpci_uart_info[i].rx_high_water;
437 			info->xmit_fifo_size = Gpci_uart_info[i].fifo_size;
438 			break;
439 		}
440 }
441 
442 static void __mxser_start_tx(struct mxser_port *info)
443 {
444 	outb(info->IER & ~UART_IER_THRI, info->ioaddr + UART_IER);
445 	info->IER |= UART_IER_THRI;
446 	outb(info->IER, info->ioaddr + UART_IER);
447 }
448 
449 static void mxser_start_tx(struct mxser_port *info)
450 {
451 	unsigned long flags;
452 
453 	spin_lock_irqsave(&info->slock, flags);
454 	__mxser_start_tx(info);
455 	spin_unlock_irqrestore(&info->slock, flags);
456 }
457 
458 static void __mxser_stop_tx(struct mxser_port *info)
459 {
460 	info->IER &= ~UART_IER_THRI;
461 	outb(info->IER, info->ioaddr + UART_IER);
462 }
463 
464 static int mxser_carrier_raised(struct tty_port *port)
465 {
466 	struct mxser_port *mp = container_of(port, struct mxser_port, port);
467 	return (inb(mp->ioaddr + UART_MSR) & UART_MSR_DCD)?1:0;
468 }
469 
470 static void mxser_dtr_rts(struct tty_port *port, int on)
471 {
472 	struct mxser_port *mp = container_of(port, struct mxser_port, port);
473 	unsigned long flags;
474 	u8 mcr;
475 
476 	spin_lock_irqsave(&mp->slock, flags);
477 	mcr = inb(mp->ioaddr + UART_MCR);
478 	if (on)
479 		mcr |= UART_MCR_DTR | UART_MCR_RTS;
480 	else
481 		mcr &= ~(UART_MCR_DTR | UART_MCR_RTS);
482 	outb(mcr, mp->ioaddr + UART_MCR);
483 	spin_unlock_irqrestore(&mp->slock, flags);
484 }
485 
486 static int mxser_set_baud(struct tty_struct *tty, speed_t newspd)
487 {
488 	struct mxser_port *info = tty->driver_data;
489 	unsigned int quot = 0, baud;
490 	unsigned char cval;
491 	u64 timeout;
492 
493 	if (newspd > info->board->max_baud)
494 		return -1;
495 
496 	if (newspd == 134) {
497 		quot = 2 * MXSER_BAUD_BASE / 269;
498 		tty_encode_baud_rate(tty, 134, 134);
499 	} else if (newspd) {
500 		quot = MXSER_BAUD_BASE / newspd;
501 		if (quot == 0)
502 			quot = 1;
503 		baud = MXSER_BAUD_BASE / quot;
504 		tty_encode_baud_rate(tty, baud, baud);
505 	} else {
506 		quot = 0;
507 	}
508 
509 	/*
510 	 * worst case (128 * 1000 * 10 * 18432) needs 35 bits, so divide in the
511 	 * u64 domain
512 	 */
513 	timeout = (u64)info->xmit_fifo_size * HZ * 10 * quot;
514 	do_div(timeout, MXSER_BAUD_BASE);
515 	info->timeout = timeout + HZ / 50; /* Add .02 seconds of slop */
516 
517 	if (quot) {
518 		info->MCR |= UART_MCR_DTR;
519 		outb(info->MCR, info->ioaddr + UART_MCR);
520 	} else {
521 		info->MCR &= ~UART_MCR_DTR;
522 		outb(info->MCR, info->ioaddr + UART_MCR);
523 		return 0;
524 	}
525 
526 	cval = inb(info->ioaddr + UART_LCR);
527 
528 	outb(cval | UART_LCR_DLAB, info->ioaddr + UART_LCR);	/* set DLAB */
529 
530 	outb(quot & 0xff, info->ioaddr + UART_DLL);	/* LS of divisor */
531 	outb(quot >> 8, info->ioaddr + UART_DLM);	/* MS of divisor */
532 	outb(cval, info->ioaddr + UART_LCR);	/* reset DLAB */
533 
534 #ifdef BOTHER
535 	if (C_BAUD(tty) == BOTHER) {
536 		quot = MXSER_BAUD_BASE % newspd;
537 		quot *= 8;
538 		if (quot % newspd > newspd / 2) {
539 			quot /= newspd;
540 			quot++;
541 		} else
542 			quot /= newspd;
543 
544 		mxser_set_must_enum_value(info->ioaddr, quot);
545 	} else
546 #endif
547 		mxser_set_must_enum_value(info->ioaddr, 0);
548 
549 	return 0;
550 }
551 
552 static void mxser_handle_cts(struct tty_struct *tty, struct mxser_port *info,
553 		u8 msr)
554 {
555 	bool cts = msr & UART_MSR_CTS;
556 
557 	if (tty->hw_stopped) {
558 		if (cts) {
559 			tty->hw_stopped = 0;
560 
561 			if (!mxser_16550A_or_MUST(info))
562 				__mxser_start_tx(info);
563 			tty_wakeup(tty);
564 		}
565 		return;
566 	} else if (cts)
567 		return;
568 
569 	tty->hw_stopped = 1;
570 	if (!mxser_16550A_or_MUST(info))
571 		__mxser_stop_tx(info);
572 }
573 
574 /*
575  * This routine is called to set the UART divisor registers to match
576  * the specified baud rate for a serial port.
577  */
578 static void mxser_change_speed(struct tty_struct *tty, struct ktermios *old_termios)
579 {
580 	struct mxser_port *info = tty->driver_data;
581 	unsigned cflag, cval;
582 
583 	cflag = tty->termios.c_cflag;
584 
585 	if (mxser_set_baud(tty, tty_get_baud_rate(tty))) {
586 		/* Use previous rate on a failure */
587 		if (old_termios) {
588 			speed_t baud = tty_termios_baud_rate(old_termios);
589 			tty_encode_baud_rate(tty, baud, baud);
590 		}
591 	}
592 
593 	/* byte size and parity */
594 	switch (cflag & CSIZE) {
595 	default:
596 	case CS5:
597 		cval = UART_LCR_WLEN5;
598 		break;
599 	case CS6:
600 		cval = UART_LCR_WLEN6;
601 		break;
602 	case CS7:
603 		cval = UART_LCR_WLEN7;
604 		break;
605 	case CS8:
606 		cval = UART_LCR_WLEN8;
607 		break;
608 	}
609 
610 	if (cflag & CSTOPB)
611 		cval |= UART_LCR_STOP;
612 	if (cflag & PARENB)
613 		cval |= UART_LCR_PARITY;
614 	if (!(cflag & PARODD))
615 		cval |= UART_LCR_EPAR;
616 	if (cflag & CMSPAR)
617 		cval |= UART_LCR_SPAR;
618 
619 	info->FCR = 0;
620 	if (info->board->must_hwid) {
621 		info->FCR |= UART_FCR_ENABLE_FIFO |
622 			MOXA_MUST_FCR_GDA_MODE_ENABLE;
623 		mxser_set_must_fifo_value(info);
624 	} else if (info->type != PORT_8250 && info->type != PORT_16450) {
625 		info->FCR |= UART_FCR_ENABLE_FIFO;
626 		switch (info->rx_high_water) {
627 		case 1:
628 			info->FCR |= UART_FCR_TRIGGER_1;
629 			break;
630 		case 4:
631 			info->FCR |= UART_FCR_TRIGGER_4;
632 			break;
633 		case 8:
634 			info->FCR |= UART_FCR_TRIGGER_8;
635 			break;
636 		default:
637 			info->FCR |= UART_FCR_TRIGGER_14;
638 			break;
639 		}
640 	}
641 
642 	/* CTS flow control flag and modem status interrupts */
643 	info->IER &= ~UART_IER_MSI;
644 	info->MCR &= ~UART_MCR_AFE;
645 	tty_port_set_cts_flow(&info->port, cflag & CRTSCTS);
646 	if (cflag & CRTSCTS) {
647 		info->IER |= UART_IER_MSI;
648 		if (mxser_16550A_or_MUST(info)) {
649 			info->MCR |= UART_MCR_AFE;
650 		} else {
651 			mxser_handle_cts(tty, info,
652 					inb(info->ioaddr + UART_MSR));
653 		}
654 	}
655 	outb(info->MCR, info->ioaddr + UART_MCR);
656 	tty_port_set_check_carrier(&info->port, ~cflag & CLOCAL);
657 	if (~cflag & CLOCAL)
658 		info->IER |= UART_IER_MSI;
659 	outb(info->IER, info->ioaddr + UART_IER);
660 
661 	/*
662 	 * Set up parity check flag
663 	 */
664 	info->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
665 	if (I_INPCK(tty))
666 		info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
667 	if (I_BRKINT(tty) || I_PARMRK(tty))
668 		info->read_status_mask |= UART_LSR_BI;
669 
670 	info->ignore_status_mask = 0;
671 
672 	if (I_IGNBRK(tty)) {
673 		info->ignore_status_mask |= UART_LSR_BI;
674 		info->read_status_mask |= UART_LSR_BI;
675 		/*
676 		 * If we're ignore parity and break indicators, ignore
677 		 * overruns too.  (For real raw support).
678 		 */
679 		if (I_IGNPAR(tty)) {
680 			info->ignore_status_mask |=
681 						UART_LSR_OE |
682 						UART_LSR_PE |
683 						UART_LSR_FE;
684 			info->read_status_mask |=
685 						UART_LSR_OE |
686 						UART_LSR_PE |
687 						UART_LSR_FE;
688 		}
689 	}
690 	if (info->board->must_hwid) {
691 		mxser_set_must_xon1_value(info->ioaddr, START_CHAR(tty));
692 		mxser_set_must_xoff1_value(info->ioaddr, STOP_CHAR(tty));
693 		mxser_must_set_rx_sw_flow_control(info->ioaddr, I_IXON(tty));
694 		mxser_must_set_tx_sw_flow_control(info->ioaddr, I_IXOFF(tty));
695 	}
696 
697 
698 	outb(info->FCR, info->ioaddr + UART_FCR);
699 	outb(cval, info->ioaddr + UART_LCR);
700 }
701 
702 static u8 mxser_check_modem_status(struct tty_struct *tty,
703 				struct mxser_port *port)
704 {
705 	u8 msr = inb(port->ioaddr + UART_MSR);
706 
707 	if (!(msr & UART_MSR_ANY_DELTA))
708 		return msr;
709 
710 	/* update input line counters */
711 	if (msr & UART_MSR_TERI)
712 		port->icount.rng++;
713 	if (msr & UART_MSR_DDSR)
714 		port->icount.dsr++;
715 	if (msr & UART_MSR_DDCD)
716 		port->icount.dcd++;
717 	if (msr & UART_MSR_DCTS)
718 		port->icount.cts++;
719 	wake_up_interruptible(&port->port.delta_msr_wait);
720 
721 	if (tty_port_check_carrier(&port->port) && (msr & UART_MSR_DDCD)) {
722 		if (msr & UART_MSR_DCD)
723 			wake_up_interruptible(&port->port.open_wait);
724 	}
725 
726 	if (tty_port_cts_enabled(&port->port))
727 		mxser_handle_cts(tty, port, msr);
728 
729 	return msr;
730 }
731 
732 static void mxser_disable_and_clear_FIFO(struct mxser_port *info)
733 {
734 	u8 fcr = UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT;
735 
736 	if (info->board->must_hwid)
737 		fcr |= MOXA_MUST_FCR_GDA_MODE_ENABLE;
738 
739 	outb(fcr, info->ioaddr + UART_FCR);
740 }
741 
742 static int mxser_activate(struct tty_port *port, struct tty_struct *tty)
743 {
744 	struct mxser_port *info = container_of(port, struct mxser_port, port);
745 	unsigned long page;
746 	unsigned long flags;
747 
748 	page = __get_free_page(GFP_KERNEL);
749 	if (!page)
750 		return -ENOMEM;
751 
752 	spin_lock_irqsave(&info->slock, flags);
753 
754 	if (!info->type) {
755 		set_bit(TTY_IO_ERROR, &tty->flags);
756 		free_page(page);
757 		spin_unlock_irqrestore(&info->slock, flags);
758 		return 0;
759 	}
760 	info->port.xmit_buf = (unsigned char *) page;
761 
762 	/*
763 	 * Clear the FIFO buffers and disable them
764 	 * (they will be reenabled in mxser_change_speed())
765 	 */
766 	mxser_disable_and_clear_FIFO(info);
767 
768 	/*
769 	 * At this point there's no way the LSR could still be 0xFF;
770 	 * if it is, then bail out, because there's likely no UART
771 	 * here.
772 	 */
773 	if (inb(info->ioaddr + UART_LSR) == 0xff) {
774 		spin_unlock_irqrestore(&info->slock, flags);
775 		if (capable(CAP_SYS_ADMIN)) {
776 			set_bit(TTY_IO_ERROR, &tty->flags);
777 			return 0;
778 		} else
779 			return -ENODEV;
780 	}
781 
782 	/*
783 	 * Clear the interrupt registers.
784 	 */
785 	(void) inb(info->ioaddr + UART_LSR);
786 	(void) inb(info->ioaddr + UART_RX);
787 	(void) inb(info->ioaddr + UART_IIR);
788 	(void) inb(info->ioaddr + UART_MSR);
789 
790 	/*
791 	 * Now, initialize the UART
792 	 */
793 	outb(UART_LCR_WLEN8, info->ioaddr + UART_LCR);	/* reset DLAB */
794 	info->MCR = UART_MCR_DTR | UART_MCR_RTS;
795 	outb(info->MCR, info->ioaddr + UART_MCR);
796 
797 	/*
798 	 * Finally, enable interrupts
799 	 */
800 	info->IER = UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI;
801 
802 	if (info->board->must_hwid)
803 		info->IER |= MOXA_MUST_IER_EGDAI;
804 	outb(info->IER, info->ioaddr + UART_IER);	/* enable interrupts */
805 
806 	/*
807 	 * And clear the interrupt registers again for luck.
808 	 */
809 	(void) inb(info->ioaddr + UART_LSR);
810 	(void) inb(info->ioaddr + UART_RX);
811 	(void) inb(info->ioaddr + UART_IIR);
812 	(void) inb(info->ioaddr + UART_MSR);
813 
814 	clear_bit(TTY_IO_ERROR, &tty->flags);
815 	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
816 
817 	/*
818 	 * and set the speed of the serial port
819 	 */
820 	mxser_change_speed(tty, NULL);
821 	spin_unlock_irqrestore(&info->slock, flags);
822 
823 	return 0;
824 }
825 
826 /*
827  * To stop accepting input, we disable the receive line status interrupts, and
828  * tell the interrupt driver to stop checking the data ready bit in the line
829  * status register.
830  */
831 static void mxser_stop_rx(struct mxser_port *info)
832 {
833 	info->IER &= ~UART_IER_RLSI;
834 	if (info->board->must_hwid)
835 		info->IER &= ~MOXA_MUST_RECV_ISR;
836 
837 	outb(info->IER, info->ioaddr + UART_IER);
838 }
839 
840 /*
841  * This routine will shutdown a serial port
842  */
843 static void mxser_shutdown_port(struct tty_port *port)
844 {
845 	struct mxser_port *info = container_of(port, struct mxser_port, port);
846 	unsigned long flags;
847 
848 	spin_lock_irqsave(&info->slock, flags);
849 
850 	mxser_stop_rx(info);
851 
852 	/*
853 	 * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
854 	 * here so the queue might never be waken up
855 	 */
856 	wake_up_interruptible(&info->port.delta_msr_wait);
857 
858 	/*
859 	 * Free the xmit buffer, if necessary
860 	 */
861 	if (info->port.xmit_buf) {
862 		free_page((unsigned long) info->port.xmit_buf);
863 		info->port.xmit_buf = NULL;
864 	}
865 
866 	info->IER = 0;
867 	outb(0x00, info->ioaddr + UART_IER);
868 
869 	/* clear Rx/Tx FIFO's */
870 	mxser_disable_and_clear_FIFO(info);
871 
872 	/* read data port to reset things */
873 	(void) inb(info->ioaddr + UART_RX);
874 
875 
876 	if (info->board->must_hwid)
877 		mxser_must_no_sw_flow_control(info->ioaddr);
878 
879 	spin_unlock_irqrestore(&info->slock, flags);
880 }
881 
882 /*
883  * This routine is called whenever a serial port is opened.  It
884  * enables interrupts for a serial port, linking in its async structure into
885  * the IRQ chain.   It also performs the serial-specific
886  * initialization for the tty structure.
887  */
888 static int mxser_open(struct tty_struct *tty, struct file *filp)
889 {
890 	struct tty_port *tport = tty->port;
891 	struct mxser_port *port = container_of(tport, struct mxser_port, port);
892 
893 	tty->driver_data = port;
894 
895 	return tty_port_open(tport, tty, filp);
896 }
897 
898 static void mxser_flush_buffer(struct tty_struct *tty)
899 {
900 	struct mxser_port *info = tty->driver_data;
901 	unsigned long flags;
902 
903 
904 	spin_lock_irqsave(&info->slock, flags);
905 	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
906 
907 	outb(info->FCR | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
908 		info->ioaddr + UART_FCR);
909 
910 	spin_unlock_irqrestore(&info->slock, flags);
911 
912 	tty_wakeup(tty);
913 }
914 
915 static void mxser_close(struct tty_struct *tty, struct file *filp)
916 {
917 	tty_port_close(tty->port, tty, filp);
918 }
919 
920 static int mxser_write(struct tty_struct *tty, const unsigned char *buf, int count)
921 {
922 	int c, total = 0;
923 	struct mxser_port *info = tty->driver_data;
924 	unsigned long flags;
925 
926 	while (1) {
927 		c = min_t(int, count, min(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
928 					  SERIAL_XMIT_SIZE - info->xmit_head));
929 		if (c <= 0)
930 			break;
931 
932 		memcpy(info->port.xmit_buf + info->xmit_head, buf, c);
933 		spin_lock_irqsave(&info->slock, flags);
934 		info->xmit_head = (info->xmit_head + c) &
935 				  (SERIAL_XMIT_SIZE - 1);
936 		info->xmit_cnt += c;
937 		spin_unlock_irqrestore(&info->slock, flags);
938 
939 		buf += c;
940 		count -= c;
941 		total += c;
942 	}
943 
944 	if (info->xmit_cnt && !tty->flow.stopped)
945 		if (!tty->hw_stopped || mxser_16550A_or_MUST(info))
946 			mxser_start_tx(info);
947 
948 	return total;
949 }
950 
951 static int mxser_put_char(struct tty_struct *tty, unsigned char ch)
952 {
953 	struct mxser_port *info = tty->driver_data;
954 	unsigned long flags;
955 
956 	if (info->xmit_cnt >= SERIAL_XMIT_SIZE - 1)
957 		return 0;
958 
959 	spin_lock_irqsave(&info->slock, flags);
960 	info->port.xmit_buf[info->xmit_head++] = ch;
961 	info->xmit_head &= SERIAL_XMIT_SIZE - 1;
962 	info->xmit_cnt++;
963 	spin_unlock_irqrestore(&info->slock, flags);
964 
965 	return 1;
966 }
967 
968 
969 static void mxser_flush_chars(struct tty_struct *tty)
970 {
971 	struct mxser_port *info = tty->driver_data;
972 
973 	if (!info->xmit_cnt || tty->flow.stopped ||
974 			(tty->hw_stopped && !mxser_16550A_or_MUST(info)))
975 		return;
976 
977 	mxser_start_tx(info);
978 }
979 
980 static unsigned int mxser_write_room(struct tty_struct *tty)
981 {
982 	struct mxser_port *info = tty->driver_data;
983 	int ret;
984 
985 	ret = SERIAL_XMIT_SIZE - info->xmit_cnt - 1;
986 	return ret < 0 ? 0 : ret;
987 }
988 
989 static unsigned int mxser_chars_in_buffer(struct tty_struct *tty)
990 {
991 	struct mxser_port *info = tty->driver_data;
992 	return info->xmit_cnt;
993 }
994 
995 /*
996  * ------------------------------------------------------------
997  * friends of mxser_ioctl()
998  * ------------------------------------------------------------
999  */
1000 static int mxser_get_serial_info(struct tty_struct *tty,
1001 		struct serial_struct *ss)
1002 {
1003 	struct mxser_port *info = tty->driver_data;
1004 	struct tty_port *port = &info->port;
1005 	unsigned int closing_wait, close_delay;
1006 
1007 	mutex_lock(&port->mutex);
1008 
1009 	close_delay = jiffies_to_msecs(info->port.close_delay) / 10;
1010 	closing_wait = info->port.closing_wait;
1011 	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
1012 		closing_wait = jiffies_to_msecs(closing_wait) / 10;
1013 
1014 	ss->type = info->type;
1015 	ss->line = tty->index;
1016 	ss->port = info->ioaddr;
1017 	ss->irq = info->board->irq;
1018 	ss->flags = info->port.flags;
1019 	ss->baud_base = MXSER_BAUD_BASE;
1020 	ss->close_delay = close_delay;
1021 	ss->closing_wait = closing_wait;
1022 	ss->custom_divisor = MXSER_CUSTOM_DIVISOR,
1023 	mutex_unlock(&port->mutex);
1024 	return 0;
1025 }
1026 
1027 static int mxser_set_serial_info(struct tty_struct *tty,
1028 		struct serial_struct *ss)
1029 {
1030 	struct mxser_port *info = tty->driver_data;
1031 	struct tty_port *port = &info->port;
1032 	speed_t baud;
1033 	unsigned long sl_flags;
1034 	unsigned int old_speed, close_delay, closing_wait;
1035 	int retval = 0;
1036 
1037 	if (tty_io_error(tty))
1038 		return -EIO;
1039 
1040 	mutex_lock(&port->mutex);
1041 
1042 	if (ss->irq != info->board->irq ||
1043 			ss->port != info->ioaddr) {
1044 		mutex_unlock(&port->mutex);
1045 		return -EINVAL;
1046 	}
1047 
1048 	old_speed = port->flags & ASYNC_SPD_MASK;
1049 
1050 	close_delay = msecs_to_jiffies(ss->close_delay * 10);
1051 	closing_wait = ss->closing_wait;
1052 	if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
1053 		closing_wait = msecs_to_jiffies(closing_wait * 10);
1054 
1055 	if (!capable(CAP_SYS_ADMIN)) {
1056 		if ((ss->baud_base != MXSER_BAUD_BASE) ||
1057 				(close_delay != port->close_delay) ||
1058 				(closing_wait != port->closing_wait) ||
1059 				((ss->flags & ~ASYNC_USR_MASK) != (port->flags & ~ASYNC_USR_MASK))) {
1060 			mutex_unlock(&port->mutex);
1061 			return -EPERM;
1062 		}
1063 		port->flags = (port->flags & ~ASYNC_USR_MASK) |
1064 				(ss->flags & ASYNC_USR_MASK);
1065 	} else {
1066 		/*
1067 		 * OK, past this point, all the error checking has been done.
1068 		 * At this point, we start making changes.....
1069 		 */
1070 		port->flags = ((port->flags & ~ASYNC_FLAGS) |
1071 				(ss->flags & ASYNC_FLAGS));
1072 		port->close_delay = close_delay;
1073 		port->closing_wait = closing_wait;
1074 		if ((port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST &&
1075 				(ss->baud_base != MXSER_BAUD_BASE ||
1076 				ss->custom_divisor !=
1077 				MXSER_CUSTOM_DIVISOR)) {
1078 			if (ss->custom_divisor == 0) {
1079 				mutex_unlock(&port->mutex);
1080 				return -EINVAL;
1081 			}
1082 			baud = ss->baud_base / ss->custom_divisor;
1083 			tty_encode_baud_rate(tty, baud, baud);
1084 		}
1085 
1086 		info->type = ss->type;
1087 
1088 		mxser_process_txrx_fifo(info);
1089 	}
1090 
1091 	if (tty_port_initialized(port)) {
1092 		if (old_speed != (port->flags & ASYNC_SPD_MASK)) {
1093 			spin_lock_irqsave(&info->slock, sl_flags);
1094 			mxser_change_speed(tty, NULL);
1095 			spin_unlock_irqrestore(&info->slock, sl_flags);
1096 		}
1097 	} else {
1098 		retval = mxser_activate(port, tty);
1099 		if (retval == 0)
1100 			tty_port_set_initialized(port, 1);
1101 	}
1102 	mutex_unlock(&port->mutex);
1103 	return retval;
1104 }
1105 
1106 /*
1107  * mxser_get_lsr_info - get line status register info
1108  *
1109  * Purpose: Let user call ioctl() to get info when the UART physically
1110  *	    is emptied.  On bus types like RS485, the transmitter must
1111  *	    release the bus after transmitting. This must be done when
1112  *	    the transmit shift register is empty, not be done when the
1113  *	    transmit holding register is empty.  This functionality
1114  *	    allows an RS485 driver to be written in user space.
1115  */
1116 static int mxser_get_lsr_info(struct mxser_port *info,
1117 		unsigned int __user *value)
1118 {
1119 	unsigned char status;
1120 	unsigned int result;
1121 	unsigned long flags;
1122 
1123 	spin_lock_irqsave(&info->slock, flags);
1124 	status = inb(info->ioaddr + UART_LSR);
1125 	spin_unlock_irqrestore(&info->slock, flags);
1126 	result = ((status & UART_LSR_TEMT) ? TIOCSER_TEMT : 0);
1127 	return put_user(result, value);
1128 }
1129 
1130 static int mxser_tiocmget(struct tty_struct *tty)
1131 {
1132 	struct mxser_port *info = tty->driver_data;
1133 	unsigned char control;
1134 	unsigned long flags;
1135 	u8 msr;
1136 
1137 	if (tty_io_error(tty))
1138 		return -EIO;
1139 
1140 	spin_lock_irqsave(&info->slock, flags);
1141 	control = info->MCR;
1142 	msr = mxser_check_modem_status(tty, info);
1143 	spin_unlock_irqrestore(&info->slock, flags);
1144 
1145 	return ((control & UART_MCR_RTS) ? TIOCM_RTS : 0) |
1146 		    ((control & UART_MCR_DTR) ? TIOCM_DTR : 0) |
1147 		    ((msr & UART_MSR_DCD) ? TIOCM_CAR : 0) |
1148 		    ((msr & UART_MSR_RI) ? TIOCM_RNG : 0) |
1149 		    ((msr & UART_MSR_DSR) ? TIOCM_DSR : 0) |
1150 		    ((msr & UART_MSR_CTS) ? TIOCM_CTS : 0);
1151 }
1152 
1153 static int mxser_tiocmset(struct tty_struct *tty,
1154 		unsigned int set, unsigned int clear)
1155 {
1156 	struct mxser_port *info = tty->driver_data;
1157 	unsigned long flags;
1158 
1159 	if (tty_io_error(tty))
1160 		return -EIO;
1161 
1162 	spin_lock_irqsave(&info->slock, flags);
1163 
1164 	if (set & TIOCM_RTS)
1165 		info->MCR |= UART_MCR_RTS;
1166 	if (set & TIOCM_DTR)
1167 		info->MCR |= UART_MCR_DTR;
1168 
1169 	if (clear & TIOCM_RTS)
1170 		info->MCR &= ~UART_MCR_RTS;
1171 	if (clear & TIOCM_DTR)
1172 		info->MCR &= ~UART_MCR_DTR;
1173 
1174 	outb(info->MCR, info->ioaddr + UART_MCR);
1175 	spin_unlock_irqrestore(&info->slock, flags);
1176 	return 0;
1177 }
1178 
1179 static int mxser_cflags_changed(struct mxser_port *info, unsigned long arg,
1180 		struct async_icount *cprev)
1181 {
1182 	struct async_icount cnow;
1183 	unsigned long flags;
1184 	int ret;
1185 
1186 	spin_lock_irqsave(&info->slock, flags);
1187 	cnow = info->icount;	/* atomic copy */
1188 	spin_unlock_irqrestore(&info->slock, flags);
1189 
1190 	ret =	((arg & TIOCM_RNG) && (cnow.rng != cprev->rng)) ||
1191 		((arg & TIOCM_DSR) && (cnow.dsr != cprev->dsr)) ||
1192 		((arg & TIOCM_CD)  && (cnow.dcd != cprev->dcd)) ||
1193 		((arg & TIOCM_CTS) && (cnow.cts != cprev->cts));
1194 
1195 	*cprev = cnow;
1196 
1197 	return ret;
1198 }
1199 
1200 /* We should likely switch to TIOCGRS485/TIOCSRS485. */
1201 static int mxser_ioctl_op_mode(struct mxser_port *port, int index, bool set,
1202 		int __user *u_opmode)
1203 {
1204 	int opmode, p = index % 4;
1205 	int shiftbit = p * 2;
1206 	u8 val;
1207 
1208 	if (port->board->must_hwid != MOXA_MUST_MU860_HWID)
1209 		return -EFAULT;
1210 
1211 	if (set) {
1212 		if (get_user(opmode, u_opmode))
1213 			return -EFAULT;
1214 
1215 		if (opmode & ~OP_MODE_MASK)
1216 			return -EINVAL;
1217 
1218 		spin_lock_irq(&port->slock);
1219 		val = inb(port->opmode_ioaddr);
1220 		val &= ~(OP_MODE_MASK << shiftbit);
1221 		val |= (opmode << shiftbit);
1222 		outb(val, port->opmode_ioaddr);
1223 		spin_unlock_irq(&port->slock);
1224 
1225 		return 0;
1226 	}
1227 
1228 	spin_lock_irq(&port->slock);
1229 	opmode = inb(port->opmode_ioaddr) >> shiftbit;
1230 	spin_unlock_irq(&port->slock);
1231 
1232 	return put_user(opmode & OP_MODE_MASK, u_opmode);
1233 }
1234 
1235 static int mxser_ioctl(struct tty_struct *tty,
1236 		unsigned int cmd, unsigned long arg)
1237 {
1238 	struct mxser_port *info = tty->driver_data;
1239 	struct async_icount cnow;
1240 	unsigned long flags;
1241 	void __user *argp = (void __user *)arg;
1242 
1243 	if (cmd == MOXA_SET_OP_MODE || cmd == MOXA_GET_OP_MODE)
1244 		return mxser_ioctl_op_mode(info, tty->index,
1245 				cmd == MOXA_SET_OP_MODE, argp);
1246 
1247 	if (cmd != TIOCMIWAIT && tty_io_error(tty))
1248 		return -EIO;
1249 
1250 	switch (cmd) {
1251 	case TIOCSERGETLSR:	/* Get line status register */
1252 		return  mxser_get_lsr_info(info, argp);
1253 		/*
1254 		 * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
1255 		 * - mask passed in arg for lines of interest
1256 		 *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
1257 		 * Caller should use TIOCGICOUNT to see which one it was
1258 		 */
1259 	case TIOCMIWAIT:
1260 		spin_lock_irqsave(&info->slock, flags);
1261 		cnow = info->icount;	/* note the counters on entry */
1262 		spin_unlock_irqrestore(&info->slock, flags);
1263 
1264 		return wait_event_interruptible(info->port.delta_msr_wait,
1265 				mxser_cflags_changed(info, arg, &cnow));
1266 	default:
1267 		return -ENOIOCTLCMD;
1268 	}
1269 	return 0;
1270 }
1271 
1272 	/*
1273 	 * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
1274 	 * Return: write counters to the user passed counter struct
1275 	 * NB: both 1->0 and 0->1 transitions are counted except for
1276 	 *     RI where only 0->1 is counted.
1277 	 */
1278 
1279 static int mxser_get_icount(struct tty_struct *tty,
1280 		struct serial_icounter_struct *icount)
1281 
1282 {
1283 	struct mxser_port *info = tty->driver_data;
1284 	struct async_icount cnow;
1285 	unsigned long flags;
1286 
1287 	spin_lock_irqsave(&info->slock, flags);
1288 	cnow = info->icount;
1289 	spin_unlock_irqrestore(&info->slock, flags);
1290 
1291 	icount->frame = cnow.frame;
1292 	icount->brk = cnow.brk;
1293 	icount->overrun = cnow.overrun;
1294 	icount->buf_overrun = cnow.buf_overrun;
1295 	icount->parity = cnow.parity;
1296 	icount->rx = cnow.rx;
1297 	icount->tx = cnow.tx;
1298 	icount->cts = cnow.cts;
1299 	icount->dsr = cnow.dsr;
1300 	icount->rng = cnow.rng;
1301 	icount->dcd = cnow.dcd;
1302 	return 0;
1303 }
1304 
1305 /*
1306  * This routine is called by the upper-layer tty layer to signal that
1307  * incoming characters should be throttled.
1308  */
1309 static void mxser_throttle(struct tty_struct *tty)
1310 {
1311 	struct mxser_port *info = tty->driver_data;
1312 
1313 	if (I_IXOFF(tty)) {
1314 		if (info->board->must_hwid) {
1315 			info->IER &= ~MOXA_MUST_RECV_ISR;
1316 			outb(info->IER, info->ioaddr + UART_IER);
1317 		} else {
1318 			info->x_char = STOP_CHAR(tty);
1319 			outb(0, info->ioaddr + UART_IER);
1320 			info->IER |= UART_IER_THRI;
1321 			outb(info->IER, info->ioaddr + UART_IER);
1322 		}
1323 	}
1324 
1325 	if (C_CRTSCTS(tty)) {
1326 		info->MCR &= ~UART_MCR_RTS;
1327 		outb(info->MCR, info->ioaddr + UART_MCR);
1328 	}
1329 }
1330 
1331 static void mxser_unthrottle(struct tty_struct *tty)
1332 {
1333 	struct mxser_port *info = tty->driver_data;
1334 
1335 	/* startrx */
1336 	if (I_IXOFF(tty)) {
1337 		if (info->x_char)
1338 			info->x_char = 0;
1339 		else {
1340 			if (info->board->must_hwid) {
1341 				info->IER |= MOXA_MUST_RECV_ISR;
1342 				outb(info->IER, info->ioaddr + UART_IER);
1343 			} else {
1344 				info->x_char = START_CHAR(tty);
1345 				outb(0, info->ioaddr + UART_IER);
1346 				info->IER |= UART_IER_THRI;
1347 				outb(info->IER, info->ioaddr + UART_IER);
1348 			}
1349 		}
1350 	}
1351 
1352 	if (C_CRTSCTS(tty)) {
1353 		info->MCR |= UART_MCR_RTS;
1354 		outb(info->MCR, info->ioaddr + UART_MCR);
1355 	}
1356 }
1357 
1358 /*
1359  * mxser_stop() and mxser_start()
1360  *
1361  * This routines are called before setting or resetting tty->flow.stopped.
1362  * They enable or disable transmitter interrupts, as necessary.
1363  */
1364 static void mxser_stop(struct tty_struct *tty)
1365 {
1366 	struct mxser_port *info = tty->driver_data;
1367 	unsigned long flags;
1368 
1369 	spin_lock_irqsave(&info->slock, flags);
1370 	if (info->IER & UART_IER_THRI)
1371 		__mxser_stop_tx(info);
1372 	spin_unlock_irqrestore(&info->slock, flags);
1373 }
1374 
1375 static void mxser_start(struct tty_struct *tty)
1376 {
1377 	struct mxser_port *info = tty->driver_data;
1378 	unsigned long flags;
1379 
1380 	spin_lock_irqsave(&info->slock, flags);
1381 	if (info->xmit_cnt)
1382 		__mxser_start_tx(info);
1383 	spin_unlock_irqrestore(&info->slock, flags);
1384 }
1385 
1386 static void mxser_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
1387 {
1388 	struct mxser_port *info = tty->driver_data;
1389 	unsigned long flags;
1390 
1391 	spin_lock_irqsave(&info->slock, flags);
1392 	mxser_change_speed(tty, old_termios);
1393 	spin_unlock_irqrestore(&info->slock, flags);
1394 
1395 	if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
1396 		tty->hw_stopped = 0;
1397 		mxser_start(tty);
1398 	}
1399 
1400 	/* Handle sw stopped */
1401 	if ((old_termios->c_iflag & IXON) && !I_IXON(tty)) {
1402 		tty->flow.stopped = 0;
1403 
1404 		if (info->board->must_hwid) {
1405 			spin_lock_irqsave(&info->slock, flags);
1406 			mxser_must_set_rx_sw_flow_control(info->ioaddr, false);
1407 			spin_unlock_irqrestore(&info->slock, flags);
1408 		}
1409 
1410 		mxser_start(tty);
1411 	}
1412 }
1413 
1414 static bool mxser_tx_empty(struct mxser_port *info)
1415 {
1416 	unsigned long flags;
1417 	u8 lsr;
1418 
1419 	spin_lock_irqsave(&info->slock, flags);
1420 	lsr = inb(info->ioaddr + UART_LSR);
1421 	spin_unlock_irqrestore(&info->slock, flags);
1422 
1423 	return !(lsr & UART_LSR_TEMT);
1424 }
1425 
1426 /*
1427  * mxser_wait_until_sent() --- wait until the transmitter is empty
1428  */
1429 static void mxser_wait_until_sent(struct tty_struct *tty, int timeout)
1430 {
1431 	struct mxser_port *info = tty->driver_data;
1432 	unsigned long expire, char_time;
1433 
1434 	if (info->type == PORT_UNKNOWN)
1435 		return;
1436 
1437 	if (info->xmit_fifo_size == 0)
1438 		return;		/* Just in case.... */
1439 
1440 	/*
1441 	 * Set the check interval to be 1/5 of the estimated time to
1442 	 * send a single character, and make it at least 1.  The check
1443 	 * interval should also be less than the timeout.
1444 	 *
1445 	 * Note: we have to use pretty tight timings here to satisfy
1446 	 * the NIST-PCTS.
1447 	 */
1448 	char_time = (info->timeout - HZ / 50) / info->xmit_fifo_size;
1449 	char_time = char_time / 5;
1450 	if (char_time == 0)
1451 		char_time = 1;
1452 	if (timeout && timeout < char_time)
1453 		char_time = timeout;
1454 
1455 	char_time = jiffies_to_msecs(char_time);
1456 
1457 	/*
1458 	 * If the transmitter hasn't cleared in twice the approximate
1459 	 * amount of time to send the entire FIFO, it probably won't
1460 	 * ever clear.  This assumes the UART isn't doing flow
1461 	 * control, which is currently the case.  Hence, if it ever
1462 	 * takes longer than info->timeout, this is probably due to a
1463 	 * UART bug of some kind.  So, we clamp the timeout parameter at
1464 	 * 2*info->timeout.
1465 	 */
1466 	if (!timeout || timeout > 2 * info->timeout)
1467 		timeout = 2 * info->timeout;
1468 
1469 	expire = jiffies + timeout;
1470 
1471 	while (mxser_tx_empty(info)) {
1472 		msleep_interruptible(char_time);
1473 		if (signal_pending(current))
1474 			break;
1475 		if (time_after(jiffies, expire))
1476 			break;
1477 	}
1478 }
1479 
1480 /*
1481  * This routine is called by tty_hangup() when a hangup is signaled.
1482  */
1483 static void mxser_hangup(struct tty_struct *tty)
1484 {
1485 	struct mxser_port *info = tty->driver_data;
1486 
1487 	mxser_flush_buffer(tty);
1488 	tty_port_hangup(&info->port);
1489 }
1490 
1491 /*
1492  * mxser_rs_break() --- routine which turns the break handling on or off
1493  */
1494 static int mxser_rs_break(struct tty_struct *tty, int break_state)
1495 {
1496 	struct mxser_port *info = tty->driver_data;
1497 	unsigned long flags;
1498 	u8 lcr;
1499 
1500 	spin_lock_irqsave(&info->slock, flags);
1501 	lcr = inb(info->ioaddr + UART_LCR);
1502 	if (break_state == -1)
1503 		lcr |= UART_LCR_SBC;
1504 	else
1505 		lcr &= ~UART_LCR_SBC;
1506 	outb(lcr, info->ioaddr + UART_LCR);
1507 	spin_unlock_irqrestore(&info->slock, flags);
1508 
1509 	return 0;
1510 }
1511 
1512 static bool mxser_receive_chars_new(struct mxser_port *port, u8 status)
1513 {
1514 	enum mxser_must_hwid hwid = port->board->must_hwid;
1515 	u8 gdl;
1516 
1517 	if (hwid == MOXA_OTHER_UART)
1518 		return false;
1519 	if (status & (UART_LSR_BRK_ERROR_BITS | MOXA_MUST_LSR_RERR))
1520 		return false;
1521 
1522 	gdl = inb(port->ioaddr + MOXA_MUST_GDL_REGISTER);
1523 	if (hwid == MOXA_MUST_MU150_HWID)
1524 		gdl &= MOXA_MUST_GDL_MASK;
1525 
1526 	while (gdl--) {
1527 		u8 ch = inb(port->ioaddr + UART_RX);
1528 		if (!tty_insert_flip_char(&port->port, ch, 0))
1529 			port->icount.buf_overrun++;
1530 	}
1531 
1532 	return true;
1533 }
1534 
1535 static u8 mxser_receive_chars_old(struct tty_struct *tty,
1536 		                struct mxser_port *port, u8 status)
1537 {
1538 	enum mxser_must_hwid hwid = port->board->must_hwid;
1539 	int ignored = 0;
1540 	int max = 256;
1541 	u8 ch;
1542 
1543 	do {
1544 		if (max-- < 0)
1545 			break;
1546 
1547 		ch = inb(port->ioaddr + UART_RX);
1548 		if (hwid && (status & UART_LSR_OE))
1549 			outb(port->FCR | UART_FCR_CLEAR_RCVR,
1550 					port->ioaddr + UART_FCR);
1551 		status &= port->read_status_mask;
1552 		if (status & port->ignore_status_mask) {
1553 			if (++ignored > 100)
1554 				break;
1555 		} else {
1556 			char flag = 0;
1557 			if (status & UART_LSR_BRK_ERROR_BITS) {
1558 				if (status & UART_LSR_BI) {
1559 					flag = TTY_BREAK;
1560 					port->icount.brk++;
1561 
1562 					if (port->port.flags & ASYNC_SAK)
1563 						do_SAK(tty);
1564 				} else if (status & UART_LSR_PE) {
1565 					flag = TTY_PARITY;
1566 					port->icount.parity++;
1567 				} else if (status & UART_LSR_FE) {
1568 					flag = TTY_FRAME;
1569 					port->icount.frame++;
1570 				} else if (status & UART_LSR_OE) {
1571 					flag = TTY_OVERRUN;
1572 					port->icount.overrun++;
1573 				}
1574 			}
1575 			if (!tty_insert_flip_char(&port->port, ch, flag)) {
1576 				port->icount.buf_overrun++;
1577 				break;
1578 			}
1579 		}
1580 
1581 		if (hwid)
1582 			break;
1583 
1584 		status = inb(port->ioaddr + UART_LSR);
1585 	} while (status & UART_LSR_DR);
1586 
1587 	return status;
1588 }
1589 
1590 static u8 mxser_receive_chars(struct tty_struct *tty,
1591 		struct mxser_port *port, u8 status)
1592 {
1593 	if (!mxser_receive_chars_new(port, status))
1594 		status = mxser_receive_chars_old(tty, port, status);
1595 
1596 	tty_flip_buffer_push(&port->port);
1597 
1598 	return status;
1599 }
1600 
1601 static void mxser_transmit_chars(struct tty_struct *tty, struct mxser_port *port)
1602 {
1603 	int count;
1604 
1605 	if (port->x_char) {
1606 		outb(port->x_char, port->ioaddr + UART_TX);
1607 		port->x_char = 0;
1608 		port->icount.tx++;
1609 		return;
1610 	}
1611 
1612 	if (!port->xmit_cnt || tty->flow.stopped ||
1613 			(tty->hw_stopped && !mxser_16550A_or_MUST(port))) {
1614 		__mxser_stop_tx(port);
1615 		return;
1616 	}
1617 
1618 	count = port->xmit_fifo_size;
1619 	do {
1620 		outb(port->port.xmit_buf[port->xmit_tail++],
1621 			port->ioaddr + UART_TX);
1622 		port->xmit_tail &= SERIAL_XMIT_SIZE - 1;
1623 		port->icount.tx++;
1624 		if (!--port->xmit_cnt)
1625 			break;
1626 	} while (--count > 0);
1627 
1628 	if (port->xmit_cnt < WAKEUP_CHARS)
1629 		tty_wakeup(tty);
1630 
1631 	if (!port->xmit_cnt)
1632 		__mxser_stop_tx(port);
1633 }
1634 
1635 static bool mxser_port_isr(struct mxser_port *port)
1636 {
1637 	struct tty_struct *tty;
1638 	u8 iir, status;
1639 	bool error = false;
1640 
1641 	iir = inb(port->ioaddr + UART_IIR);
1642 	if (iir & UART_IIR_NO_INT)
1643 		return true;
1644 
1645 	iir &= MOXA_MUST_IIR_MASK;
1646 	tty = tty_port_tty_get(&port->port);
1647 	if (!tty) {
1648 		status = inb(port->ioaddr + UART_LSR);
1649 		outb(port->FCR | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
1650 				port->ioaddr + UART_FCR);
1651 		inb(port->ioaddr + UART_MSR);
1652 
1653 		error = true;
1654 		goto put_tty;
1655 	}
1656 
1657 	status = inb(port->ioaddr + UART_LSR);
1658 
1659 	if (port->board->must_hwid) {
1660 		if (iir == MOXA_MUST_IIR_GDA ||
1661 		    iir == MOXA_MUST_IIR_RDA ||
1662 		    iir == MOXA_MUST_IIR_RTO ||
1663 		    iir == MOXA_MUST_IIR_LSR)
1664 			status = mxser_receive_chars(tty, port, status);
1665 	} else {
1666 		status &= port->read_status_mask;
1667 		if (status & UART_LSR_DR)
1668 			status = mxser_receive_chars(tty, port, status);
1669 	}
1670 
1671 	mxser_check_modem_status(tty, port);
1672 
1673 	if (port->board->must_hwid) {
1674 		if (iir == 0x02 && (status & UART_LSR_THRE))
1675 			mxser_transmit_chars(tty, port);
1676 	} else {
1677 		if (status & UART_LSR_THRE)
1678 			mxser_transmit_chars(tty, port);
1679 	}
1680 
1681 put_tty:
1682 	tty_kref_put(tty);
1683 
1684 	return error;
1685 }
1686 
1687 /*
1688  * This is the serial driver's generic interrupt routine
1689  */
1690 static irqreturn_t mxser_interrupt(int irq, void *dev_id)
1691 {
1692 	struct mxser_board *brd = dev_id;
1693 	struct mxser_port *port;
1694 	unsigned int int_cnt, pass_counter = 0;
1695 	unsigned int i, max = brd->nports;
1696 	int handled = IRQ_NONE;
1697 	u8 irqbits, bits, mask = BIT(max) - 1;
1698 
1699 	while (pass_counter++ < MXSER_ISR_PASS_LIMIT) {
1700 		irqbits = inb(brd->vector) & mask;
1701 		if (irqbits == mask)
1702 			break;
1703 
1704 		handled = IRQ_HANDLED;
1705 		for (i = 0, bits = 1; i < max; i++, irqbits |= bits, bits <<= 1) {
1706 			if (irqbits == mask)
1707 				break;
1708 			if (bits & irqbits)
1709 				continue;
1710 			port = &brd->ports[i];
1711 
1712 			int_cnt = 0;
1713 			spin_lock(&port->slock);
1714 			do {
1715 				if (mxser_port_isr(port))
1716 					break;
1717 			} while (int_cnt++ < MXSER_ISR_PASS_LIMIT);
1718 			spin_unlock(&port->slock);
1719 		}
1720 	}
1721 
1722 	return handled;
1723 }
1724 
1725 static const struct tty_operations mxser_ops = {
1726 	.open = mxser_open,
1727 	.close = mxser_close,
1728 	.write = mxser_write,
1729 	.put_char = mxser_put_char,
1730 	.flush_chars = mxser_flush_chars,
1731 	.write_room = mxser_write_room,
1732 	.chars_in_buffer = mxser_chars_in_buffer,
1733 	.flush_buffer = mxser_flush_buffer,
1734 	.ioctl = mxser_ioctl,
1735 	.throttle = mxser_throttle,
1736 	.unthrottle = mxser_unthrottle,
1737 	.set_termios = mxser_set_termios,
1738 	.stop = mxser_stop,
1739 	.start = mxser_start,
1740 	.hangup = mxser_hangup,
1741 	.break_ctl = mxser_rs_break,
1742 	.wait_until_sent = mxser_wait_until_sent,
1743 	.tiocmget = mxser_tiocmget,
1744 	.tiocmset = mxser_tiocmset,
1745 	.set_serial = mxser_set_serial_info,
1746 	.get_serial = mxser_get_serial_info,
1747 	.get_icount = mxser_get_icount,
1748 };
1749 
1750 static const struct tty_port_operations mxser_port_ops = {
1751 	.carrier_raised = mxser_carrier_raised,
1752 	.dtr_rts = mxser_dtr_rts,
1753 	.activate = mxser_activate,
1754 	.shutdown = mxser_shutdown_port,
1755 };
1756 
1757 /*
1758  * The MOXA Smartio/Industio serial driver boot-time initialization code!
1759  */
1760 
1761 static void mxser_initbrd(struct mxser_board *brd, bool high_baud)
1762 {
1763 	struct mxser_port *info;
1764 	unsigned int i;
1765 	bool is_mu860;
1766 
1767 	brd->must_hwid = mxser_must_get_hwid(brd->ports[0].ioaddr);
1768 	is_mu860 = brd->must_hwid == MOXA_MUST_MU860_HWID;
1769 
1770 	for (i = 0; i < UART_INFO_NUM; i++) {
1771 		if (Gpci_uart_info[i].type == brd->must_hwid) {
1772 			brd->max_baud = Gpci_uart_info[i].max_baud;
1773 
1774 			/* exception....CP-102 */
1775 			if (high_baud)
1776 				brd->max_baud = 921600;
1777 			break;
1778 		}
1779 	}
1780 
1781 	if (is_mu860) {
1782 		/* set to RS232 mode by default */
1783 		outb(0, brd->vector + 4);
1784 		outb(0, brd->vector + 0x0c);
1785 	}
1786 
1787 	for (i = 0; i < brd->nports; i++) {
1788 		info = &brd->ports[i];
1789 		if (is_mu860) {
1790 			if (i < 4)
1791 				info->opmode_ioaddr = brd->vector + 4;
1792 			else
1793 				info->opmode_ioaddr = brd->vector + 0x0c;
1794 		}
1795 		tty_port_init(&info->port);
1796 		info->port.ops = &mxser_port_ops;
1797 		info->board = brd;
1798 
1799 		/* Enhance mode enabled here */
1800 		if (brd->must_hwid != MOXA_OTHER_UART)
1801 			mxser_must_set_enhance_mode(info->ioaddr, true);
1802 
1803 		info->type = PORT_16550A;
1804 
1805 		mxser_process_txrx_fifo(info);
1806 
1807 		info->port.close_delay = 5 * HZ / 10;
1808 		info->port.closing_wait = 30 * HZ;
1809 		spin_lock_init(&info->slock);
1810 
1811 		/* before set INT ISR, disable all int */
1812 		outb(inb(info->ioaddr + UART_IER) & 0xf0,
1813 			info->ioaddr + UART_IER);
1814 	}
1815 }
1816 
1817 static int mxser_probe(struct pci_dev *pdev,
1818 		const struct pci_device_id *ent)
1819 {
1820 	struct mxser_board *brd;
1821 	unsigned int i, base;
1822 	unsigned long ioaddress;
1823 	unsigned short nports = MXSER_NPORTS(ent->driver_data);
1824 	struct device *tty_dev;
1825 	int retval = -EINVAL;
1826 
1827 	i = find_first_zero_bit(mxser_boards, MXSER_BOARDS);
1828 	if (i >= MXSER_BOARDS) {
1829 		dev_err(&pdev->dev, "too many boards found (maximum %d), board "
1830 				"not configured\n", MXSER_BOARDS);
1831 		goto err;
1832 	}
1833 
1834 	brd = devm_kzalloc(&pdev->dev, struct_size(brd, ports, nports),
1835 			GFP_KERNEL);
1836 	if (!brd)
1837 		goto err;
1838 
1839 	brd->idx = i;
1840 	__set_bit(brd->idx, mxser_boards);
1841 	base = i * MXSER_PORTS_PER_BOARD;
1842 
1843 	retval = pcim_enable_device(pdev);
1844 	if (retval) {
1845 		dev_err(&pdev->dev, "PCI enable failed\n");
1846 		goto err_zero;
1847 	}
1848 
1849 	/* io address */
1850 	ioaddress = pci_resource_start(pdev, 2);
1851 	retval = pci_request_region(pdev, 2, "mxser(IO)");
1852 	if (retval)
1853 		goto err_zero;
1854 
1855 	brd->nports = nports;
1856 	for (i = 0; i < nports; i++)
1857 		brd->ports[i].ioaddr = ioaddress + 8 * i;
1858 
1859 	/* vector */
1860 	ioaddress = pci_resource_start(pdev, 3);
1861 	retval = pci_request_region(pdev, 3, "mxser(vector)");
1862 	if (retval)
1863 		goto err_zero;
1864 	brd->vector = ioaddress;
1865 
1866 	/* irq */
1867 	brd->irq = pdev->irq;
1868 
1869 	mxser_initbrd(brd, ent->driver_data & MXSER_HIGHBAUD);
1870 
1871 	retval = devm_request_irq(&pdev->dev, brd->irq, mxser_interrupt,
1872 			IRQF_SHARED, "mxser", brd);
1873 	if (retval) {
1874 		dev_err(&pdev->dev, "request irq failed");
1875 		goto err_relbrd;
1876 	}
1877 
1878 	for (i = 0; i < nports; i++) {
1879 		tty_dev = tty_port_register_device(&brd->ports[i].port,
1880 				mxvar_sdriver, base + i, &pdev->dev);
1881 		if (IS_ERR(tty_dev)) {
1882 			retval = PTR_ERR(tty_dev);
1883 			for (; i > 0; i--)
1884 				tty_unregister_device(mxvar_sdriver,
1885 					base + i - 1);
1886 			goto err_relbrd;
1887 		}
1888 	}
1889 
1890 	pci_set_drvdata(pdev, brd);
1891 
1892 	return 0;
1893 err_relbrd:
1894 	for (i = 0; i < nports; i++)
1895 		tty_port_destroy(&brd->ports[i].port);
1896 err_zero:
1897 	__clear_bit(brd->idx, mxser_boards);
1898 err:
1899 	return retval;
1900 }
1901 
1902 static void mxser_remove(struct pci_dev *pdev)
1903 {
1904 	struct mxser_board *brd = pci_get_drvdata(pdev);
1905 	unsigned int i, base = brd->idx * MXSER_PORTS_PER_BOARD;
1906 
1907 	for (i = 0; i < brd->nports; i++) {
1908 		tty_unregister_device(mxvar_sdriver, base + i);
1909 		tty_port_destroy(&brd->ports[i].port);
1910 	}
1911 
1912 	__clear_bit(brd->idx, mxser_boards);
1913 }
1914 
1915 static struct pci_driver mxser_driver = {
1916 	.name = "mxser",
1917 	.id_table = mxser_pcibrds,
1918 	.probe = mxser_probe,
1919 	.remove = mxser_remove
1920 };
1921 
1922 static int __init mxser_module_init(void)
1923 {
1924 	int retval;
1925 
1926 	mxvar_sdriver = tty_alloc_driver(MXSER_PORTS, TTY_DRIVER_REAL_RAW |
1927 			TTY_DRIVER_DYNAMIC_DEV);
1928 	if (IS_ERR(mxvar_sdriver))
1929 		return PTR_ERR(mxvar_sdriver);
1930 
1931 	/* Initialize the tty_driver structure */
1932 	mxvar_sdriver->name = "ttyMI";
1933 	mxvar_sdriver->major = ttymajor;
1934 	mxvar_sdriver->minor_start = 0;
1935 	mxvar_sdriver->type = TTY_DRIVER_TYPE_SERIAL;
1936 	mxvar_sdriver->subtype = SERIAL_TYPE_NORMAL;
1937 	mxvar_sdriver->init_termios = tty_std_termios;
1938 	mxvar_sdriver->init_termios.c_cflag = B9600|CS8|CREAD|HUPCL|CLOCAL;
1939 	tty_set_operations(mxvar_sdriver, &mxser_ops);
1940 
1941 	retval = tty_register_driver(mxvar_sdriver);
1942 	if (retval) {
1943 		printk(KERN_ERR "Couldn't install MOXA Smartio/Industio family "
1944 				"tty driver !\n");
1945 		goto err_put;
1946 	}
1947 
1948 	retval = pci_register_driver(&mxser_driver);
1949 	if (retval) {
1950 		printk(KERN_ERR "mxser: can't register pci driver\n");
1951 		goto err_unr;
1952 	}
1953 
1954 	return 0;
1955 err_unr:
1956 	tty_unregister_driver(mxvar_sdriver);
1957 err_put:
1958 	tty_driver_kref_put(mxvar_sdriver);
1959 	return retval;
1960 }
1961 
1962 static void __exit mxser_module_exit(void)
1963 {
1964 	pci_unregister_driver(&mxser_driver);
1965 	tty_unregister_driver(mxvar_sdriver);
1966 	tty_driver_kref_put(mxvar_sdriver);
1967 }
1968 
1969 module_init(mxser_module_init);
1970 module_exit(mxser_module_exit);
1971