xref: /openbmc/linux/drivers/usb/serial/mos7720.c (revision fa251f89903d73989e2f63e13d0eaed1e07ce0da)
1 /*
2  * mos7720.c
3  *   Controls the Moschip 7720 usb to dual port serial convertor
4  *
5  * Copyright 2006 Moschip Semiconductor Tech. Ltd.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation, version 2 of the License.
10  *
11  * Developed by:
12  * 	Vijaya Kumar <vijaykumar.gn@gmail.com>
13  *	Ajay Kumar <naanuajay@yahoo.com>
14  *	Gurudeva <ngurudeva@yahoo.com>
15  *
16  * Cleaned up from the original by:
17  *	Greg Kroah-Hartman <gregkh@suse.de>
18  *
19  * Originally based on drivers/usb/serial/io_edgeport.c which is:
20  *	Copyright (C) 2000 Inside Out Networks, All rights reserved.
21  *	Copyright (C) 2001-2002 Greg Kroah-Hartman <greg@kroah.com>
22  */
23 #include <linux/kernel.h>
24 #include <linux/errno.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/tty.h>
28 #include <linux/tty_driver.h>
29 #include <linux/tty_flip.h>
30 #include <linux/module.h>
31 #include <linux/spinlock.h>
32 #include <linux/serial.h>
33 #include <linux/serial_reg.h>
34 #include <linux/usb.h>
35 #include <linux/usb/serial.h>
36 #include <linux/uaccess.h>
37 #include <linux/parport.h>
38 
39 /*
40  * Version Information
41  */
42 #define DRIVER_VERSION "2.1"
43 #define DRIVER_AUTHOR "Aspire Communications pvt Ltd."
44 #define DRIVER_DESC "Moschip USB Serial Driver"
45 
46 /* default urb timeout */
47 #define MOS_WDR_TIMEOUT	(HZ * 5)
48 
49 #define MOS_MAX_PORT	0x02
50 #define MOS_WRITE	0x0E
51 #define MOS_READ	0x0D
52 
53 /* Interrupt Rotinue Defines	*/
54 #define SERIAL_IIR_RLS	0x06
55 #define SERIAL_IIR_RDA	0x04
56 #define SERIAL_IIR_CTI	0x0c
57 #define SERIAL_IIR_THR	0x02
58 #define SERIAL_IIR_MS	0x00
59 
60 #define NUM_URBS			16	/* URB Count */
61 #define URB_TRANSFER_BUFFER_SIZE	32	/* URB Size */
62 
63 /* This structure holds all of the local serial port information */
64 struct moschip_port {
65 	__u8	shadowLCR;		/* last LCR value received */
66 	__u8	shadowMCR;		/* last MCR value received */
67 	__u8	shadowMSR;		/* last MSR value received */
68 	char			open;
69 	struct async_icount	icount;
70 	struct usb_serial_port	*port;	/* loop back to the owner */
71 	struct urb		*write_urb_pool[NUM_URBS];
72 };
73 
74 static int debug;
75 
76 static struct usb_serial_driver moschip7720_2port_driver;
77 
78 #define USB_VENDOR_ID_MOSCHIP		0x9710
79 #define MOSCHIP_DEVICE_ID_7720		0x7720
80 #define MOSCHIP_DEVICE_ID_7715		0x7715
81 
82 static const struct usb_device_id moschip_port_id_table[] = {
83 	{ USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7720) },
84 	{ USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7715) },
85 	{ } /* terminating entry */
86 };
87 MODULE_DEVICE_TABLE(usb, moschip_port_id_table);
88 
89 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
90 
91 /* initial values for parport regs */
92 #define DCR_INIT_VAL       0x0c	/* SLCTIN, nINIT */
93 #define ECR_INIT_VAL       0x00	/* SPP mode */
94 
95 struct urbtracker {
96 	struct mos7715_parport  *mos_parport;
97 	struct list_head        urblist_entry;
98 	struct kref             ref_count;
99 	struct urb              *urb;
100 };
101 
102 enum mos7715_pp_modes {
103 	SPP = 0<<5,
104 	PS2 = 1<<5,      /* moschip calls this 'NIBBLE' mode */
105 	PPF = 2<<5,	 /* moschip calls this 'CB-FIFO mode */
106 };
107 
108 struct mos7715_parport {
109 	struct parport          *pp;	       /* back to containing struct */
110 	struct kref             ref_count;     /* to instance of this struct */
111 	struct list_head        deferred_urbs; /* list deferred async urbs */
112 	struct list_head        active_urbs;   /* list async urbs in flight */
113 	spinlock_t              listlock;      /* protects list access */
114 	bool                    msg_pending;   /* usb sync call pending */
115 	struct completion       syncmsg_compl; /* usb sync call completed */
116 	struct tasklet_struct   urb_tasklet;   /* for sending deferred urbs */
117 	struct usb_serial       *serial;       /* back to containing struct */
118 	__u8	                shadowECR;     /* parallel port regs... */
119 	__u8	                shadowDCR;
120 	atomic_t                shadowDSR;     /* updated in int-in callback */
121 };
122 
123 /* lock guards against dereferencing NULL ptr in parport ops callbacks */
124 static DEFINE_SPINLOCK(release_lock);
125 
126 #endif	/* CONFIG_USB_SERIAL_MOS7715_PARPORT */
127 
128 static const unsigned int dummy; /* for clarity in register access fns */
129 
130 enum mos_regs {
131 	THR,	          /* serial port regs */
132 	RHR,
133 	IER,
134 	FCR,
135 	ISR,
136 	LCR,
137 	MCR,
138 	LSR,
139 	MSR,
140 	SPR,
141 	DLL,
142 	DLM,
143 	DPR,              /* parallel port regs */
144 	DSR,
145 	DCR,
146 	ECR,
147 	SP1_REG,          /* device control regs */
148 	SP2_REG,          /* serial port 2 (7720 only) */
149 	PP_REG,
150 	SP_CONTROL_REG,
151 };
152 
153 /*
154  * Return the correct value for the Windex field of the setup packet
155  * for a control endpoint message.  See the 7715 datasheet.
156  */
157 static inline __u16 get_reg_index(enum mos_regs reg)
158 {
159 	static const __u16 mos7715_index_lookup_table[] = {
160 		0x00,		/* THR */
161 		0x00,		/* RHR */
162 		0x01,		/* IER */
163 		0x02,		/* FCR */
164 		0x02,		/* ISR */
165 		0x03,		/* LCR */
166 		0x04,		/* MCR */
167 		0x05,		/* LSR */
168 		0x06,		/* MSR */
169 		0x07,		/* SPR */
170 		0x00,		/* DLL */
171 		0x01,		/* DLM */
172 		0x00,		/* DPR */
173 		0x01,		/* DSR */
174 		0x02,		/* DCR */
175 		0x0a,		/* ECR */
176 		0x01,		/* SP1_REG */
177 		0x02,		/* SP2_REG (7720 only) */
178 		0x04,		/* PP_REG (7715 only) */
179 		0x08,		/* SP_CONTROL_REG */
180 	};
181 	return mos7715_index_lookup_table[reg];
182 }
183 
184 /*
185  * Return the correct value for the upper byte of the Wvalue field of
186  * the setup packet for a control endpoint message.
187  */
188 static inline __u16 get_reg_value(enum mos_regs reg,
189 				  unsigned int serial_portnum)
190 {
191 	if (reg >= SP1_REG)	      /* control reg */
192 		return 0x0000;
193 
194 	else if (reg >= DPR)	      /* parallel port reg (7715 only) */
195 		return 0x0100;
196 
197 	else			      /* serial port reg */
198 		return (serial_portnum + 2) << 8;
199 }
200 
201 /*
202  * Write data byte to the specified device register.  The data is embedded in
203  * the value field of the setup packet. serial_portnum is ignored for registers
204  * not specific to a particular serial port.
205  */
206 static int write_mos_reg(struct usb_serial *serial, unsigned int serial_portnum,
207 			 enum mos_regs reg, __u8 data)
208 {
209 	struct usb_device *usbdev = serial->dev;
210 	unsigned int pipe = usb_sndctrlpipe(usbdev, 0);
211 	__u8 request = (__u8)0x0e;
212 	__u8 requesttype = (__u8)0x40;
213 	__u16 index = get_reg_index(reg);
214 	__u16 value = get_reg_value(reg, serial_portnum) + data;
215 	int status = usb_control_msg(usbdev, pipe, request, requesttype, value,
216 				     index, NULL, 0, MOS_WDR_TIMEOUT);
217 	if (status < 0)
218 		dev_err(&usbdev->dev,
219 			"mos7720: usb_control_msg() failed: %d", status);
220 	return status;
221 }
222 
223 /*
224  * Read data byte from the specified device register.  The data returned by the
225  * device is embedded in the value field of the setup packet.  serial_portnum is
226  * ignored for registers that are not specific to a particular serial port.
227  */
228 static int read_mos_reg(struct usb_serial *serial, unsigned int serial_portnum,
229 			enum mos_regs reg, __u8 *data)
230 {
231 	struct usb_device *usbdev = serial->dev;
232 	unsigned int pipe = usb_rcvctrlpipe(usbdev, 0);
233 	__u8 request = (__u8)0x0d;
234 	__u8 requesttype = (__u8)0xc0;
235 	__u16 index = get_reg_index(reg);
236 	__u16 value = get_reg_value(reg, serial_portnum);
237 	int status = usb_control_msg(usbdev, pipe, request, requesttype, value,
238 				     index, data, 1, MOS_WDR_TIMEOUT);
239 	if (status < 0)
240 		dev_err(&usbdev->dev,
241 			"mos7720: usb_control_msg() failed: %d", status);
242 	return status;
243 }
244 
245 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
246 
247 static inline int mos7715_change_mode(struct mos7715_parport *mos_parport,
248 				      enum mos7715_pp_modes mode)
249 {
250 	mos_parport->shadowECR = mode;
251 	write_mos_reg(mos_parport->serial, dummy, ECR, mos_parport->shadowECR);
252 	return 0;
253 }
254 
255 static void destroy_mos_parport(struct kref *kref)
256 {
257 	struct mos7715_parport *mos_parport =
258 		container_of(kref, struct mos7715_parport, ref_count);
259 
260 	dbg("%s called", __func__);
261 	kfree(mos_parport);
262 }
263 
264 static void destroy_urbtracker(struct kref *kref)
265 {
266 	struct urbtracker *urbtrack =
267 		container_of(kref, struct urbtracker, ref_count);
268 	struct mos7715_parport *mos_parport = urbtrack->mos_parport;
269 	dbg("%s called", __func__);
270 	usb_free_urb(urbtrack->urb);
271 	kfree(urbtrack);
272 	kref_put(&mos_parport->ref_count, destroy_mos_parport);
273 }
274 
275 /*
276  * This runs as a tasklet when sending an urb in a non-blocking parallel
277  * port callback had to be deferred because the disconnect mutex could not be
278  * obtained at the time.
279  */
280 static void send_deferred_urbs(unsigned long _mos_parport)
281 {
282 	int ret_val;
283 	unsigned long flags;
284 	struct mos7715_parport *mos_parport = (void *)_mos_parport;
285 	struct urbtracker *urbtrack;
286 	struct list_head *cursor, *next;
287 
288 	dbg("%s called", __func__);
289 
290 	/* if release function ran, game over */
291 	if (unlikely(mos_parport->serial == NULL))
292 		return;
293 
294 	/* try again to get the mutex */
295 	if (!mutex_trylock(&mos_parport->serial->disc_mutex)) {
296 		dbg("%s: rescheduling tasklet", __func__);
297 		tasklet_schedule(&mos_parport->urb_tasklet);
298 		return;
299 	}
300 
301 	/* if device disconnected, game over */
302 	if (unlikely(mos_parport->serial->disconnected)) {
303 		mutex_unlock(&mos_parport->serial->disc_mutex);
304 		return;
305 	}
306 
307 	spin_lock_irqsave(&mos_parport->listlock, flags);
308 	if (list_empty(&mos_parport->deferred_urbs)) {
309 		spin_unlock_irqrestore(&mos_parport->listlock, flags);
310 		mutex_unlock(&mos_parport->serial->disc_mutex);
311 		dbg("%s: deferred_urbs list empty", __func__);
312 		return;
313 	}
314 
315 	/* move contents of deferred_urbs list to active_urbs list and submit */
316 	list_for_each_safe(cursor, next, &mos_parport->deferred_urbs)
317 		list_move_tail(cursor, &mos_parport->active_urbs);
318 	list_for_each_entry(urbtrack, &mos_parport->active_urbs,
319 			    urblist_entry) {
320 		ret_val = usb_submit_urb(urbtrack->urb, GFP_ATOMIC);
321 		dbg("%s: urb submitted", __func__);
322 		if (ret_val) {
323 			dev_err(&mos_parport->serial->dev->dev,
324 				"usb_submit_urb() failed: %d", ret_val);
325 			list_del(&urbtrack->urblist_entry);
326 			kref_put(&urbtrack->ref_count, destroy_urbtracker);
327 		}
328 	}
329 	spin_unlock_irqrestore(&mos_parport->listlock, flags);
330 	mutex_unlock(&mos_parport->serial->disc_mutex);
331 }
332 
333 /* callback for parallel port control urbs submitted asynchronously */
334 static void async_complete(struct urb *urb)
335 {
336 	struct urbtracker *urbtrack = urb->context;
337 	int status = urb->status;
338 	dbg("%s called", __func__);
339 	if (unlikely(status))
340 		dbg("%s - nonzero urb status received: %d", __func__, status);
341 
342 	/* remove the urbtracker from the active_urbs list */
343 	spin_lock(&urbtrack->mos_parport->listlock);
344 	list_del(&urbtrack->urblist_entry);
345 	spin_unlock(&urbtrack->mos_parport->listlock);
346 	kref_put(&urbtrack->ref_count, destroy_urbtracker);
347 }
348 
349 static int write_parport_reg_nonblock(struct mos7715_parport *mos_parport,
350 				      enum mos_regs reg, __u8 data)
351 {
352 	struct urbtracker *urbtrack;
353 	int ret_val;
354 	unsigned long flags;
355 	struct usb_ctrlrequest setup;
356 	struct usb_serial *serial = mos_parport->serial;
357 	struct usb_device *usbdev = serial->dev;
358 	dbg("%s called", __func__);
359 
360 	/* create and initialize the control urb and containing urbtracker */
361 	urbtrack = kmalloc(sizeof(struct urbtracker), GFP_ATOMIC);
362 	if (urbtrack == NULL) {
363 		dev_err(&usbdev->dev, "out of memory");
364 		return -ENOMEM;
365 	}
366 	kref_get(&mos_parport->ref_count);
367 	urbtrack->mos_parport = mos_parport;
368 	urbtrack->urb = usb_alloc_urb(0, GFP_ATOMIC);
369 	if (urbtrack->urb == NULL) {
370 		dev_err(&usbdev->dev, "out of urbs");
371 		kfree(urbtrack);
372 		return -ENOMEM;
373 	}
374 	setup.bRequestType = (__u8)0x40;
375 	setup.bRequest = (__u8)0x0e;
376 	setup.wValue = get_reg_value(reg, dummy);
377 	setup.wIndex = get_reg_index(reg);
378 	setup.wLength = 0;
379 	usb_fill_control_urb(urbtrack->urb, usbdev,
380 			     usb_sndctrlpipe(usbdev, 0),
381 			     (unsigned char *)&setup,
382 			     NULL, 0, async_complete, urbtrack);
383 	kref_init(&urbtrack->ref_count);
384 	INIT_LIST_HEAD(&urbtrack->urblist_entry);
385 
386 	/*
387 	 * get the disconnect mutex, or add tracker to the deferred_urbs list
388 	 * and schedule a tasklet to try again later
389 	 */
390 	if (!mutex_trylock(&serial->disc_mutex)) {
391 		spin_lock_irqsave(&mos_parport->listlock, flags);
392 		list_add_tail(&urbtrack->urblist_entry,
393 			      &mos_parport->deferred_urbs);
394 		spin_unlock_irqrestore(&mos_parport->listlock, flags);
395 		tasklet_schedule(&mos_parport->urb_tasklet);
396 		dbg("tasklet scheduled");
397 		return 0;
398 	}
399 
400 	/* bail if device disconnected */
401 	if (serial->disconnected) {
402 		kref_put(&urbtrack->ref_count, destroy_urbtracker);
403 		mutex_unlock(&serial->disc_mutex);
404 		return -ENODEV;
405 	}
406 
407 	/* add the tracker to the active_urbs list and submit */
408 	spin_lock_irqsave(&mos_parport->listlock, flags);
409 	list_add_tail(&urbtrack->urblist_entry, &mos_parport->active_urbs);
410 	spin_unlock_irqrestore(&mos_parport->listlock, flags);
411 	ret_val = usb_submit_urb(urbtrack->urb, GFP_ATOMIC);
412 	mutex_unlock(&serial->disc_mutex);
413 	if (ret_val) {
414 		dev_err(&usbdev->dev,
415 			"%s: submit_urb() failed: %d", __func__, ret_val);
416 		spin_lock_irqsave(&mos_parport->listlock, flags);
417 		list_del(&urbtrack->urblist_entry);
418 		spin_unlock_irqrestore(&mos_parport->listlock, flags);
419 		kref_put(&urbtrack->ref_count, destroy_urbtracker);
420 		return ret_val;
421 	}
422 	return 0;
423 }
424 
425 /*
426  * This is the the common top part of all parallel port callback operations that
427  * send synchronous messages to the device.  This implements convoluted locking
428  * that avoids two scenarios: (1) a port operation is called after usbserial
429  * has called our release function, at which point struct mos7715_parport has
430  * been destroyed, and (2) the device has been disconnected, but usbserial has
431  * not called the release function yet because someone has a serial port open.
432  * The shared release_lock prevents the first, and the mutex and disconnected
433  * flag maintained by usbserial covers the second.  We also use the msg_pending
434  * flag to ensure that all synchronous usb messgage calls have completed before
435  * our release function can return.
436  */
437 static int parport_prologue(struct parport *pp)
438 {
439 	struct mos7715_parport *mos_parport;
440 
441 	spin_lock(&release_lock);
442 	mos_parport = pp->private_data;
443 	if (unlikely(mos_parport == NULL)) {
444 		/* release fn called, port struct destroyed */
445 		spin_unlock(&release_lock);
446 		return -1;
447 	}
448 	mos_parport->msg_pending = true;   /* synch usb call pending */
449 	INIT_COMPLETION(mos_parport->syncmsg_compl);
450 	spin_unlock(&release_lock);
451 
452 	mutex_lock(&mos_parport->serial->disc_mutex);
453 	if (mos_parport->serial->disconnected) {
454 		/* device disconnected */
455 		mutex_unlock(&mos_parport->serial->disc_mutex);
456 		mos_parport->msg_pending = false;
457 		complete(&mos_parport->syncmsg_compl);
458 		return -1;
459 	}
460 
461 	return 0;
462 }
463 
464 /*
465  * This is the the common bottom part of all parallel port functions that send
466  * synchronous messages to the device.
467  */
468 static inline void parport_epilogue(struct parport *pp)
469 {
470 	struct mos7715_parport *mos_parport = pp->private_data;
471 	mutex_unlock(&mos_parport->serial->disc_mutex);
472 	mos_parport->msg_pending = false;
473 	complete(&mos_parport->syncmsg_compl);
474 }
475 
476 static void parport_mos7715_write_data(struct parport *pp, unsigned char d)
477 {
478 	struct mos7715_parport *mos_parport = pp->private_data;
479 	dbg("%s called: %2.2x", __func__, d);
480 	if (parport_prologue(pp) < 0)
481 		return;
482 	mos7715_change_mode(mos_parport, SPP);
483 	write_mos_reg(mos_parport->serial, dummy, DPR, (__u8)d);
484 	parport_epilogue(pp);
485 }
486 
487 static unsigned char parport_mos7715_read_data(struct parport *pp)
488 {
489 	struct mos7715_parport *mos_parport = pp->private_data;
490 	unsigned char d;
491 	dbg("%s called", __func__);
492 	if (parport_prologue(pp) < 0)
493 		return 0;
494 	read_mos_reg(mos_parport->serial, dummy, DPR, &d);
495 	parport_epilogue(pp);
496 	return d;
497 }
498 
499 static void parport_mos7715_write_control(struct parport *pp, unsigned char d)
500 {
501 	struct mos7715_parport *mos_parport = pp->private_data;
502 	__u8 data;
503 	dbg("%s called: %2.2x", __func__, d);
504 	if (parport_prologue(pp) < 0)
505 		return;
506 	data = ((__u8)d & 0x0f) | (mos_parport->shadowDCR & 0xf0);
507 	write_mos_reg(mos_parport->serial, dummy, DCR, data);
508 	mos_parport->shadowDCR = data;
509 	parport_epilogue(pp);
510 }
511 
512 static unsigned char parport_mos7715_read_control(struct parport *pp)
513 {
514 	struct mos7715_parport *mos_parport = pp->private_data;
515 	__u8 dcr;
516 	dbg("%s called", __func__);
517 	spin_lock(&release_lock);
518 	mos_parport = pp->private_data;
519 	if (unlikely(mos_parport == NULL)) {
520 		spin_unlock(&release_lock);
521 		return 0;
522 	}
523 	dcr = mos_parport->shadowDCR & 0x0f;
524 	spin_unlock(&release_lock);
525 	return dcr;
526 }
527 
528 static unsigned char parport_mos7715_frob_control(struct parport *pp,
529 						  unsigned char mask,
530 						  unsigned char val)
531 {
532 	struct mos7715_parport *mos_parport = pp->private_data;
533 	__u8 dcr;
534 	dbg("%s called", __func__);
535 	mask &= 0x0f;
536 	val &= 0x0f;
537 	if (parport_prologue(pp) < 0)
538 		return 0;
539 	mos_parport->shadowDCR = (mos_parport->shadowDCR & (~mask)) ^ val;
540 	write_mos_reg(mos_parport->serial, dummy, DCR, mos_parport->shadowDCR);
541 	dcr = mos_parport->shadowDCR & 0x0f;
542 	parport_epilogue(pp);
543 	return dcr;
544 }
545 
546 static unsigned char parport_mos7715_read_status(struct parport *pp)
547 {
548 	unsigned char status;
549 	struct mos7715_parport *mos_parport = pp->private_data;
550 	dbg("%s called", __func__);
551 	spin_lock(&release_lock);
552 	mos_parport = pp->private_data;
553 	if (unlikely(mos_parport == NULL)) {	/* release called */
554 		spin_unlock(&release_lock);
555 		return 0;
556 	}
557 	status = atomic_read(&mos_parport->shadowDSR) & 0xf8;
558 	spin_unlock(&release_lock);
559 	return status;
560 }
561 
562 static void parport_mos7715_enable_irq(struct parport *pp)
563 {
564 	dbg("%s called", __func__);
565 }
566 static void parport_mos7715_disable_irq(struct parport *pp)
567 {
568 	dbg("%s called", __func__);
569 }
570 
571 static void parport_mos7715_data_forward(struct parport *pp)
572 {
573 	struct mos7715_parport *mos_parport = pp->private_data;
574 	dbg("%s called", __func__);
575 	if (parport_prologue(pp) < 0)
576 		return;
577 	mos7715_change_mode(mos_parport, PS2);
578 	mos_parport->shadowDCR &=  ~0x20;
579 	write_mos_reg(mos_parport->serial, dummy, DCR, mos_parport->shadowDCR);
580 	parport_epilogue(pp);
581 }
582 
583 static void parport_mos7715_data_reverse(struct parport *pp)
584 {
585 	struct mos7715_parport *mos_parport = pp->private_data;
586 	dbg("%s called", __func__);
587 	if (parport_prologue(pp) < 0)
588 		return;
589 	mos7715_change_mode(mos_parport, PS2);
590 	mos_parport->shadowDCR |= 0x20;
591 	write_mos_reg(mos_parport->serial, dummy, DCR, mos_parport->shadowDCR);
592 	parport_epilogue(pp);
593 }
594 
595 static void parport_mos7715_init_state(struct pardevice *dev,
596 				       struct parport_state *s)
597 {
598 	dbg("%s called", __func__);
599 	s->u.pc.ctr = DCR_INIT_VAL;
600 	s->u.pc.ecr = ECR_INIT_VAL;
601 }
602 
603 /* N.B. Parport core code requires that this function not block */
604 static void parport_mos7715_save_state(struct parport *pp,
605 				       struct parport_state *s)
606 {
607 	struct mos7715_parport *mos_parport;
608 	dbg("%s called", __func__);
609 	spin_lock(&release_lock);
610 	mos_parport = pp->private_data;
611 	if (unlikely(mos_parport == NULL)) {	/* release called */
612 		spin_unlock(&release_lock);
613 		return;
614 	}
615 	s->u.pc.ctr = mos_parport->shadowDCR;
616 	s->u.pc.ecr = mos_parport->shadowECR;
617 	spin_unlock(&release_lock);
618 }
619 
620 /* N.B. Parport core code requires that this function not block */
621 static void parport_mos7715_restore_state(struct parport *pp,
622 					  struct parport_state *s)
623 {
624 	struct mos7715_parport *mos_parport;
625 	dbg("%s called", __func__);
626 	spin_lock(&release_lock);
627 	mos_parport = pp->private_data;
628 	if (unlikely(mos_parport == NULL)) {	/* release called */
629 		spin_unlock(&release_lock);
630 		return;
631 	}
632 	write_parport_reg_nonblock(mos_parport, DCR, mos_parport->shadowDCR);
633 	write_parport_reg_nonblock(mos_parport, ECR, mos_parport->shadowECR);
634 	spin_unlock(&release_lock);
635 }
636 
637 static size_t parport_mos7715_write_compat(struct parport *pp,
638 					   const void *buffer,
639 					   size_t len, int flags)
640 {
641 	int retval;
642 	struct mos7715_parport *mos_parport = pp->private_data;
643 	int actual_len;
644 	dbg("%s called: %u chars", __func__, (unsigned int)len);
645 	if (parport_prologue(pp) < 0)
646 		return 0;
647 	mos7715_change_mode(mos_parport, PPF);
648 	retval = usb_bulk_msg(mos_parport->serial->dev,
649 			      usb_sndbulkpipe(mos_parport->serial->dev, 2),
650 			      (void *)buffer, len, &actual_len,
651 			      MOS_WDR_TIMEOUT);
652 	parport_epilogue(pp);
653 	if (retval) {
654 		dev_err(&mos_parport->serial->dev->dev,
655 			"mos7720: usb_bulk_msg() failed: %d", retval);
656 		return 0;
657 	}
658 	return actual_len;
659 }
660 
661 static struct parport_operations parport_mos7715_ops = {
662 	.owner =		THIS_MODULE,
663 	.write_data =		parport_mos7715_write_data,
664 	.read_data =		parport_mos7715_read_data,
665 
666 	.write_control =	parport_mos7715_write_control,
667 	.read_control =		parport_mos7715_read_control,
668 	.frob_control =		parport_mos7715_frob_control,
669 
670 	.read_status =		parport_mos7715_read_status,
671 
672 	.enable_irq =		parport_mos7715_enable_irq,
673 	.disable_irq =		parport_mos7715_disable_irq,
674 
675 	.data_forward =		parport_mos7715_data_forward,
676 	.data_reverse =		parport_mos7715_data_reverse,
677 
678 	.init_state =		parport_mos7715_init_state,
679 	.save_state =		parport_mos7715_save_state,
680 	.restore_state =	parport_mos7715_restore_state,
681 
682 	.compat_write_data =	parport_mos7715_write_compat,
683 
684 	.nibble_read_data =	parport_ieee1284_read_nibble,
685 	.byte_read_data =	parport_ieee1284_read_byte,
686 };
687 
688 /*
689  * Allocate and initialize parallel port control struct, initialize
690  * the parallel port hardware device, and register with the parport subsystem.
691  */
692 static int mos7715_parport_init(struct usb_serial *serial)
693 {
694 	struct mos7715_parport *mos_parport;
695 
696 	/* allocate and initialize parallel port control struct */
697 	mos_parport = kzalloc(sizeof(struct mos7715_parport), GFP_KERNEL);
698 	if (mos_parport == NULL) {
699 		dbg("mos7715_parport_init: kzalloc failed");
700 		return -ENOMEM;
701 	}
702 	mos_parport->msg_pending = false;
703 	kref_init(&mos_parport->ref_count);
704 	spin_lock_init(&mos_parport->listlock);
705 	INIT_LIST_HEAD(&mos_parport->active_urbs);
706 	INIT_LIST_HEAD(&mos_parport->deferred_urbs);
707 	usb_set_serial_data(serial, mos_parport); /* hijack private pointer */
708 	mos_parport->serial = serial;
709 	tasklet_init(&mos_parport->urb_tasklet, send_deferred_urbs,
710 		     (unsigned long) mos_parport);
711 	init_completion(&mos_parport->syncmsg_compl);
712 
713 	/* cycle parallel port reset bit */
714 	write_mos_reg(mos_parport->serial, dummy, PP_REG, (__u8)0x80);
715 	write_mos_reg(mos_parport->serial, dummy, PP_REG, (__u8)0x00);
716 
717 	/* initialize device registers */
718 	mos_parport->shadowDCR = DCR_INIT_VAL;
719 	write_mos_reg(mos_parport->serial, dummy, DCR, mos_parport->shadowDCR);
720 	mos_parport->shadowECR = ECR_INIT_VAL;
721 	write_mos_reg(mos_parport->serial, dummy, ECR, mos_parport->shadowECR);
722 
723 	/* register with parport core */
724 	mos_parport->pp = parport_register_port(0, PARPORT_IRQ_NONE,
725 						PARPORT_DMA_NONE,
726 						&parport_mos7715_ops);
727 	if (mos_parport->pp == NULL) {
728 		dev_err(&serial->interface->dev,
729 			"Could not register parport\n");
730 		kref_put(&mos_parport->ref_count, destroy_mos_parport);
731 		return -EIO;
732 	}
733 	mos_parport->pp->private_data = mos_parport;
734 	mos_parport->pp->modes = PARPORT_MODE_COMPAT | PARPORT_MODE_PCSPP;
735 	mos_parport->pp->dev = &serial->interface->dev;
736 	parport_announce_port(mos_parport->pp);
737 
738 	return 0;
739 }
740 #endif	/* CONFIG_USB_SERIAL_MOS7715_PARPORT */
741 
742 /*
743  * mos7720_interrupt_callback
744  *	this is the callback function for when we have received data on the
745  *	interrupt endpoint.
746  */
747 static void mos7720_interrupt_callback(struct urb *urb)
748 {
749 	int result;
750 	int length;
751 	int status = urb->status;
752 	__u8 *data;
753 	__u8 sp1;
754 	__u8 sp2;
755 
756 	switch (status) {
757 	case 0:
758 		/* success */
759 		break;
760 	case -ECONNRESET:
761 	case -ENOENT:
762 	case -ESHUTDOWN:
763 		/* this urb is terminated, clean up */
764 		dbg("%s - urb shutting down with status: %d", __func__,
765 		    status);
766 		return;
767 	default:
768 		dbg("%s - nonzero urb status received: %d", __func__,
769 		    status);
770 		goto exit;
771 	}
772 
773 	length = urb->actual_length;
774 	data = urb->transfer_buffer;
775 
776 	/* Moschip get 4 bytes
777 	 * Byte 1 IIR Port 1 (port.number is 0)
778 	 * Byte 2 IIR Port 2 (port.number is 1)
779 	 * Byte 3 --------------
780 	 * Byte 4 FIFO status for both */
781 
782 	/* the above description is inverted
783 	 * 	oneukum 2007-03-14 */
784 
785 	if (unlikely(length != 4)) {
786 		dbg("Wrong data !!!");
787 		return;
788 	}
789 
790 	sp1 = data[3];
791 	sp2 = data[2];
792 
793 	if ((sp1 | sp2) & 0x01) {
794 		/* No Interrupt Pending in both the ports */
795 		dbg("No Interrupt !!!");
796 	} else {
797 		switch (sp1 & 0x0f) {
798 		case SERIAL_IIR_RLS:
799 			dbg("Serial Port 1: Receiver status error or address "
800 			    "bit detected in 9-bit mode\n");
801 			break;
802 		case SERIAL_IIR_CTI:
803 			dbg("Serial Port 1: Receiver time out");
804 			break;
805 		case SERIAL_IIR_MS:
806 			/* dbg("Serial Port 1: Modem status change"); */
807 			break;
808 		}
809 
810 		switch (sp2 & 0x0f) {
811 		case SERIAL_IIR_RLS:
812 			dbg("Serial Port 2: Receiver status error or address "
813 			    "bit detected in 9-bit mode");
814 			break;
815 		case SERIAL_IIR_CTI:
816 			dbg("Serial Port 2: Receiver time out");
817 			break;
818 		case SERIAL_IIR_MS:
819 			/* dbg("Serial Port 2: Modem status change"); */
820 			break;
821 		}
822 	}
823 
824 exit:
825 	result = usb_submit_urb(urb, GFP_ATOMIC);
826 	if (result)
827 		dev_err(&urb->dev->dev,
828 			"%s - Error %d submitting control urb\n",
829 			__func__, result);
830 	return;
831 }
832 
833 /*
834  * mos7715_interrupt_callback
835  *	this is the 7715's callback function for when we have received data on
836  *	the interrupt endpoint.
837  */
838 static void mos7715_interrupt_callback(struct urb *urb)
839 {
840 	int result;
841 	int length;
842 	int status = urb->status;
843 	__u8 *data;
844 	__u8 iir;
845 
846 	switch (status) {
847 	case 0:
848 		/* success */
849 		break;
850 	case -ECONNRESET:
851 	case -ENOENT:
852 	case -ESHUTDOWN:
853 	case -ENODEV:
854 		/* this urb is terminated, clean up */
855 		dbg("%s - urb shutting down with status: %d", __func__,
856 		    status);
857 		return;
858 	default:
859 		dbg("%s - nonzero urb status received: %d", __func__,
860 		    status);
861 		goto exit;
862 	}
863 
864 	length = urb->actual_length;
865 	data = urb->transfer_buffer;
866 
867 	/* Structure of data from 7715 device:
868 	 * Byte 1: IIR serial Port
869 	 * Byte 2: unused
870 	 * Byte 2: DSR parallel port
871 	 * Byte 4: FIFO status for both */
872 
873 	if (unlikely(length != 4)) {
874 		dbg("Wrong data !!!");
875 		return;
876 	}
877 
878 	iir = data[0];
879 	if (!(iir & 0x01)) {	/* serial port interrupt pending */
880 		switch (iir & 0x0f) {
881 		case SERIAL_IIR_RLS:
882 			dbg("Serial Port: Receiver status error or address "
883 			    "bit detected in 9-bit mode\n");
884 			break;
885 		case SERIAL_IIR_CTI:
886 			dbg("Serial Port: Receiver time out");
887 			break;
888 		case SERIAL_IIR_MS:
889 			/* dbg("Serial Port: Modem status change"); */
890 			break;
891 		}
892 	}
893 
894 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
895 	{       /* update local copy of DSR reg */
896 		struct usb_serial_port *port = urb->context;
897 		struct mos7715_parport *mos_parport = port->serial->private;
898 		if (unlikely(mos_parport == NULL))
899 			return;
900 		atomic_set(&mos_parport->shadowDSR, data[2]);
901 	}
902 #endif
903 
904 exit:
905 	result = usb_submit_urb(urb, GFP_ATOMIC);
906 	if (result)
907 		dev_err(&urb->dev->dev,
908 			"%s - Error %d submitting control urb\n",
909 			__func__, result);
910 	return;
911 }
912 
913 /*
914  * mos7720_bulk_in_callback
915  *	this is the callback function for when we have received data on the
916  *	bulk in endpoint.
917  */
918 static void mos7720_bulk_in_callback(struct urb *urb)
919 {
920 	int retval;
921 	unsigned char *data ;
922 	struct usb_serial_port *port;
923 	struct tty_struct *tty;
924 	int status = urb->status;
925 
926 	if (status) {
927 		dbg("nonzero read bulk status received: %d", status);
928 		return;
929 	}
930 
931 	port = urb->context;
932 
933 	dbg("Entering...%s", __func__);
934 
935 	data = urb->transfer_buffer;
936 
937 	tty = tty_port_tty_get(&port->port);
938 	if (tty && urb->actual_length) {
939 		tty_insert_flip_string(tty, data, urb->actual_length);
940 		tty_flip_buffer_push(tty);
941 	}
942 	tty_kref_put(tty);
943 
944 	if (!port->read_urb) {
945 		dbg("URB KILLED !!!");
946 		return;
947 	}
948 
949 	if (port->read_urb->status != -EINPROGRESS) {
950 		port->read_urb->dev = port->serial->dev;
951 
952 		retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
953 		if (retval)
954 			dbg("usb_submit_urb(read bulk) failed, retval = %d",
955 			    retval);
956 	}
957 }
958 
959 /*
960  * mos7720_bulk_out_data_callback
961  *	this is the callback function for when we have finished sending serial
962  *	data on the bulk out endpoint.
963  */
964 static void mos7720_bulk_out_data_callback(struct urb *urb)
965 {
966 	struct moschip_port *mos7720_port;
967 	struct tty_struct *tty;
968 	int status = urb->status;
969 
970 	if (status) {
971 		dbg("nonzero write bulk status received:%d", status);
972 		return;
973 	}
974 
975 	mos7720_port = urb->context;
976 	if (!mos7720_port) {
977 		dbg("NULL mos7720_port pointer");
978 		return ;
979 	}
980 
981 	tty = tty_port_tty_get(&mos7720_port->port->port);
982 
983 	if (tty && mos7720_port->open)
984 		tty_wakeup(tty);
985 	tty_kref_put(tty);
986 }
987 
988 /*
989  * mos77xx_probe
990  *	this function installs the appropriate read interrupt endpoint callback
991  *	depending on whether the device is a 7720 or 7715, thus avoiding costly
992  *	run-time checks in the high-frequency callback routine itself.
993  */
994 static int mos77xx_probe(struct usb_serial *serial,
995 			 const struct usb_device_id *id)
996 {
997 	if (id->idProduct == MOSCHIP_DEVICE_ID_7715)
998 		moschip7720_2port_driver.read_int_callback =
999 			mos7715_interrupt_callback;
1000 	else
1001 		moschip7720_2port_driver.read_int_callback =
1002 			mos7720_interrupt_callback;
1003 
1004 	return 0;
1005 }
1006 
1007 static int mos77xx_calc_num_ports(struct usb_serial *serial)
1008 {
1009 	u16 product = le16_to_cpu(serial->dev->descriptor.idProduct);
1010 	if (product == MOSCHIP_DEVICE_ID_7715)
1011 		return 1;
1012 
1013 	return 2;
1014 }
1015 
1016 static int mos7720_open(struct tty_struct *tty, struct usb_serial_port *port)
1017 {
1018 	struct usb_serial *serial;
1019 	struct usb_serial_port *port0;
1020 	struct urb *urb;
1021 	struct moschip_port *mos7720_port;
1022 	int response;
1023 	int port_number;
1024 	__u8 data;
1025 	int allocated_urbs = 0;
1026 	int j;
1027 
1028 	serial = port->serial;
1029 
1030 	mos7720_port = usb_get_serial_port_data(port);
1031 	if (mos7720_port == NULL)
1032 		return -ENODEV;
1033 
1034 	port0 = serial->port[0];
1035 
1036 	usb_clear_halt(serial->dev, port->write_urb->pipe);
1037 	usb_clear_halt(serial->dev, port->read_urb->pipe);
1038 
1039 	/* Initialising the write urb pool */
1040 	for (j = 0; j < NUM_URBS; ++j) {
1041 		urb = usb_alloc_urb(0, GFP_KERNEL);
1042 		mos7720_port->write_urb_pool[j] = urb;
1043 
1044 		if (urb == NULL) {
1045 			dev_err(&port->dev, "No more urbs???\n");
1046 			continue;
1047 		}
1048 
1049 		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
1050 					       GFP_KERNEL);
1051 		if (!urb->transfer_buffer) {
1052 			dev_err(&port->dev,
1053 				"%s-out of memory for urb buffers.\n",
1054 				__func__);
1055 			usb_free_urb(mos7720_port->write_urb_pool[j]);
1056 			mos7720_port->write_urb_pool[j] = NULL;
1057 			continue;
1058 		}
1059 		allocated_urbs++;
1060 	}
1061 
1062 	if (!allocated_urbs)
1063 		return -ENOMEM;
1064 
1065 	 /* Initialize MCS7720 -- Write Init values to corresponding Registers
1066 	  *
1067 	  * Register Index
1068 	  * 0 : THR/RHR
1069 	  * 1 : IER
1070 	  * 2 : FCR
1071 	  * 3 : LCR
1072 	  * 4 : MCR
1073 	  * 5 : LSR
1074 	  * 6 : MSR
1075 	  * 7 : SPR
1076 	  *
1077 	  * 0x08 : SP1/2 Control Reg
1078 	  */
1079 	port_number = port->number - port->serial->minor;
1080 	read_mos_reg(serial, port_number, LSR, &data);
1081 
1082 	dbg("SS::%p LSR:%x", mos7720_port, data);
1083 
1084 	dbg("Check:Sending Command ..........");
1085 
1086 	write_mos_reg(serial, dummy, SP1_REG, 0x02);
1087 	write_mos_reg(serial, dummy, SP2_REG, 0x02);
1088 
1089 	write_mos_reg(serial, port_number, IER, 0x00);
1090 	write_mos_reg(serial, port_number, FCR, 0x00);
1091 
1092 	write_mos_reg(serial, port_number, FCR, 0xcf);
1093 	mos7720_port->shadowLCR = 0x03;
1094 	write_mos_reg(serial, port_number, LCR, mos7720_port->shadowLCR);
1095 	mos7720_port->shadowMCR = 0x0b;
1096 	write_mos_reg(serial, port_number, MCR, mos7720_port->shadowMCR);
1097 
1098 	write_mos_reg(serial, port_number, SP_CONTROL_REG, 0x00);
1099 	read_mos_reg(serial, dummy, SP_CONTROL_REG, &data);
1100 	data = data | (port->number - port->serial->minor + 1);
1101 	write_mos_reg(serial, dummy, SP_CONTROL_REG, data);
1102 	mos7720_port->shadowLCR = 0x83;
1103 	write_mos_reg(serial, port_number, LCR, mos7720_port->shadowLCR);
1104 	write_mos_reg(serial, port_number, THR, 0x0c);
1105 	write_mos_reg(serial, port_number, IER, 0x00);
1106 	mos7720_port->shadowLCR = 0x03;
1107 	write_mos_reg(serial, port_number, LCR, mos7720_port->shadowLCR);
1108 	write_mos_reg(serial, port_number, IER, 0x0c);
1109 
1110 	response = usb_submit_urb(port->read_urb, GFP_KERNEL);
1111 	if (response)
1112 		dev_err(&port->dev, "%s - Error %d submitting read urb\n",
1113 							__func__, response);
1114 
1115 	/* initialize our icount structure */
1116 	memset(&(mos7720_port->icount), 0x00, sizeof(mos7720_port->icount));
1117 
1118 	/* initialize our port settings */
1119 	mos7720_port->shadowMCR = UART_MCR_OUT2; /* Must set to enable ints! */
1120 
1121 	/* send a open port command */
1122 	mos7720_port->open = 1;
1123 
1124 	return 0;
1125 }
1126 
1127 /*
1128  * mos7720_chars_in_buffer
1129  *	this function is called by the tty driver when it wants to know how many
1130  *	bytes of data we currently have outstanding in the port (data that has
1131  *	been written, but hasn't made it out the port yet)
1132  *	If successful, we return the number of bytes left to be written in the
1133  *	system,
1134  *	Otherwise we return a negative error number.
1135  */
1136 static int mos7720_chars_in_buffer(struct tty_struct *tty)
1137 {
1138 	struct usb_serial_port *port = tty->driver_data;
1139 	int i;
1140 	int chars = 0;
1141 	struct moschip_port *mos7720_port;
1142 
1143 	dbg("%s:entering ...........", __func__);
1144 
1145 	mos7720_port = usb_get_serial_port_data(port);
1146 	if (mos7720_port == NULL) {
1147 		dbg("%s:leaving ...........", __func__);
1148 		return 0;
1149 	}
1150 
1151 	for (i = 0; i < NUM_URBS; ++i) {
1152 		if (mos7720_port->write_urb_pool[i] &&
1153 		    mos7720_port->write_urb_pool[i]->status == -EINPROGRESS)
1154 			chars += URB_TRANSFER_BUFFER_SIZE;
1155 	}
1156 	dbg("%s - returns %d", __func__, chars);
1157 	return chars;
1158 }
1159 
1160 static void mos7720_close(struct usb_serial_port *port)
1161 {
1162 	struct usb_serial *serial;
1163 	struct moschip_port *mos7720_port;
1164 	int j;
1165 
1166 	dbg("mos7720_close:entering...");
1167 
1168 	serial = port->serial;
1169 
1170 	mos7720_port = usb_get_serial_port_data(port);
1171 	if (mos7720_port == NULL)
1172 		return;
1173 
1174 	for (j = 0; j < NUM_URBS; ++j)
1175 		usb_kill_urb(mos7720_port->write_urb_pool[j]);
1176 
1177 	/* Freeing Write URBs */
1178 	for (j = 0; j < NUM_URBS; ++j) {
1179 		if (mos7720_port->write_urb_pool[j]) {
1180 			kfree(mos7720_port->write_urb_pool[j]->transfer_buffer);
1181 			usb_free_urb(mos7720_port->write_urb_pool[j]);
1182 		}
1183 	}
1184 
1185 	/* While closing port, shutdown all bulk read, write  *
1186 	 * and interrupt read if they exists, otherwise nop   */
1187 	dbg("Shutdown bulk write");
1188 	usb_kill_urb(port->write_urb);
1189 	dbg("Shutdown bulk read");
1190 	usb_kill_urb(port->read_urb);
1191 
1192 	mutex_lock(&serial->disc_mutex);
1193 	/* these commands must not be issued if the device has
1194 	 * been disconnected */
1195 	if (!serial->disconnected) {
1196 		write_mos_reg(serial, port->number - port->serial->minor,
1197 			      MCR, 0x00);
1198 		write_mos_reg(serial, port->number - port->serial->minor,
1199 			      IER, 0x00);
1200 	}
1201 	mutex_unlock(&serial->disc_mutex);
1202 	mos7720_port->open = 0;
1203 
1204 	dbg("Leaving %s", __func__);
1205 }
1206 
1207 static void mos7720_break(struct tty_struct *tty, int break_state)
1208 {
1209 	struct usb_serial_port *port = tty->driver_data;
1210 	unsigned char data;
1211 	struct usb_serial *serial;
1212 	struct moschip_port *mos7720_port;
1213 
1214 	dbg("Entering %s", __func__);
1215 
1216 	serial = port->serial;
1217 
1218 	mos7720_port = usb_get_serial_port_data(port);
1219 	if (mos7720_port == NULL)
1220 		return;
1221 
1222 	if (break_state == -1)
1223 		data = mos7720_port->shadowLCR | UART_LCR_SBC;
1224 	else
1225 		data = mos7720_port->shadowLCR & ~UART_LCR_SBC;
1226 
1227 	mos7720_port->shadowLCR  = data;
1228 	write_mos_reg(serial, port->number - port->serial->minor,
1229 		      LCR, mos7720_port->shadowLCR);
1230 
1231 	return;
1232 }
1233 
1234 /*
1235  * mos7720_write_room
1236  *	this function is called by the tty driver when it wants to know how many
1237  *	bytes of data we can accept for a specific port.
1238  *	If successful, we return the amount of room that we have for this port
1239  *	Otherwise we return a negative error number.
1240  */
1241 static int mos7720_write_room(struct tty_struct *tty)
1242 {
1243 	struct usb_serial_port *port = tty->driver_data;
1244 	struct moschip_port *mos7720_port;
1245 	int room = 0;
1246 	int i;
1247 
1248 	dbg("%s:entering ...........", __func__);
1249 
1250 	mos7720_port = usb_get_serial_port_data(port);
1251 	if (mos7720_port == NULL) {
1252 		dbg("%s:leaving ...........", __func__);
1253 		return -ENODEV;
1254 	}
1255 
1256 	/* FIXME: Locking */
1257 	for (i = 0; i < NUM_URBS; ++i) {
1258 		if (mos7720_port->write_urb_pool[i] &&
1259 		    mos7720_port->write_urb_pool[i]->status != -EINPROGRESS)
1260 			room += URB_TRANSFER_BUFFER_SIZE;
1261 	}
1262 
1263 	dbg("%s - returns %d", __func__, room);
1264 	return room;
1265 }
1266 
1267 static int mos7720_write(struct tty_struct *tty, struct usb_serial_port *port,
1268 				 const unsigned char *data, int count)
1269 {
1270 	int status;
1271 	int i;
1272 	int bytes_sent = 0;
1273 	int transfer_size;
1274 
1275 	struct moschip_port *mos7720_port;
1276 	struct usb_serial *serial;
1277 	struct urb    *urb;
1278 	const unsigned char *current_position = data;
1279 
1280 	dbg("%s:entering ...........", __func__);
1281 
1282 	serial = port->serial;
1283 
1284 	mos7720_port = usb_get_serial_port_data(port);
1285 	if (mos7720_port == NULL) {
1286 		dbg("mos7720_port is NULL");
1287 		return -ENODEV;
1288 	}
1289 
1290 	/* try to find a free urb in the list */
1291 	urb = NULL;
1292 
1293 	for (i = 0; i < NUM_URBS; ++i) {
1294 		if (mos7720_port->write_urb_pool[i] &&
1295 		    mos7720_port->write_urb_pool[i]->status != -EINPROGRESS) {
1296 			urb = mos7720_port->write_urb_pool[i];
1297 			dbg("URB:%d", i);
1298 			break;
1299 		}
1300 	}
1301 
1302 	if (urb == NULL) {
1303 		dbg("%s - no more free urbs", __func__);
1304 		goto exit;
1305 	}
1306 
1307 	if (urb->transfer_buffer == NULL) {
1308 		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
1309 					       GFP_KERNEL);
1310 		if (urb->transfer_buffer == NULL) {
1311 			dev_err(&port->dev, "%s no more kernel memory...\n",
1312 				__func__);
1313 			goto exit;
1314 		}
1315 	}
1316 	transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
1317 
1318 	memcpy(urb->transfer_buffer, current_position, transfer_size);
1319 	usb_serial_debug_data(debug, &port->dev, __func__, transfer_size,
1320 			      urb->transfer_buffer);
1321 
1322 	/* fill urb with data and submit  */
1323 	usb_fill_bulk_urb(urb, serial->dev,
1324 			  usb_sndbulkpipe(serial->dev,
1325 					port->bulk_out_endpointAddress),
1326 			  urb->transfer_buffer, transfer_size,
1327 			  mos7720_bulk_out_data_callback, mos7720_port);
1328 
1329 	/* send it down the pipe */
1330 	status = usb_submit_urb(urb, GFP_ATOMIC);
1331 	if (status) {
1332 		dev_err(&port->dev, "%s - usb_submit_urb(write bulk) failed "
1333 			"with status = %d\n", __func__, status);
1334 		bytes_sent = status;
1335 		goto exit;
1336 	}
1337 	bytes_sent = transfer_size;
1338 
1339 exit:
1340 	return bytes_sent;
1341 }
1342 
1343 static void mos7720_throttle(struct tty_struct *tty)
1344 {
1345 	struct usb_serial_port *port = tty->driver_data;
1346 	struct moschip_port *mos7720_port;
1347 	int status;
1348 
1349 	dbg("%s- port %d", __func__, port->number);
1350 
1351 	mos7720_port = usb_get_serial_port_data(port);
1352 
1353 	if (mos7720_port == NULL)
1354 		return;
1355 
1356 	if (!mos7720_port->open) {
1357 		dbg("port not opened");
1358 		return;
1359 	}
1360 
1361 	dbg("%s: Entering ..........", __func__);
1362 
1363 	/* if we are implementing XON/XOFF, send the stop character */
1364 	if (I_IXOFF(tty)) {
1365 		unsigned char stop_char = STOP_CHAR(tty);
1366 		status = mos7720_write(tty, port, &stop_char, 1);
1367 		if (status <= 0)
1368 			return;
1369 	}
1370 
1371 	/* if we are implementing RTS/CTS, toggle that line */
1372 	if (tty->termios->c_cflag & CRTSCTS) {
1373 		mos7720_port->shadowMCR &= ~UART_MCR_RTS;
1374 		write_mos_reg(port->serial, port->number - port->serial->minor,
1375 			      MCR, mos7720_port->shadowMCR);
1376 		if (status != 0)
1377 			return;
1378 	}
1379 }
1380 
1381 static void mos7720_unthrottle(struct tty_struct *tty)
1382 {
1383 	struct usb_serial_port *port = tty->driver_data;
1384 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
1385 	int status;
1386 
1387 	if (mos7720_port == NULL)
1388 		return;
1389 
1390 	if (!mos7720_port->open) {
1391 		dbg("%s - port not opened", __func__);
1392 		return;
1393 	}
1394 
1395 	dbg("%s: Entering ..........", __func__);
1396 
1397 	/* if we are implementing XON/XOFF, send the start character */
1398 	if (I_IXOFF(tty)) {
1399 		unsigned char start_char = START_CHAR(tty);
1400 		status = mos7720_write(tty, port, &start_char, 1);
1401 		if (status <= 0)
1402 			return;
1403 	}
1404 
1405 	/* if we are implementing RTS/CTS, toggle that line */
1406 	if (tty->termios->c_cflag & CRTSCTS) {
1407 		mos7720_port->shadowMCR |= UART_MCR_RTS;
1408 		write_mos_reg(port->serial, port->number - port->serial->minor,
1409 			      MCR, mos7720_port->shadowMCR);
1410 		if (status != 0)
1411 			return;
1412 	}
1413 }
1414 
1415 /* FIXME: this function does not work */
1416 static int set_higher_rates(struct moschip_port *mos7720_port,
1417 			    unsigned int baud)
1418 {
1419 	struct usb_serial_port *port;
1420 	struct usb_serial *serial;
1421 	int port_number;
1422 	enum mos_regs sp_reg;
1423 	if (mos7720_port == NULL)
1424 		return -EINVAL;
1425 
1426 	port = mos7720_port->port;
1427 	serial = port->serial;
1428 
1429 	 /***********************************************
1430 	 *      Init Sequence for higher rates
1431 	 ***********************************************/
1432 	dbg("Sending Setting Commands ..........");
1433 	port_number = port->number - port->serial->minor;
1434 
1435 	write_mos_reg(serial, port_number, IER, 0x00);
1436 	write_mos_reg(serial, port_number, FCR, 0x00);
1437 	write_mos_reg(serial, port_number, FCR, 0xcf);
1438 	mos7720_port->shadowMCR = 0x0b;
1439 	write_mos_reg(serial, port_number, MCR, mos7720_port->shadowMCR);
1440 	write_mos_reg(serial, dummy, SP_CONTROL_REG, 0x00);
1441 
1442 	/***********************************************
1443 	 *              Set for higher rates           *
1444 	 ***********************************************/
1445 	/* writing baud rate verbatum into uart clock field clearly not right */
1446 	if (port_number == 0)
1447 		sp_reg = SP1_REG;
1448 	else
1449 		sp_reg = SP2_REG;
1450 	write_mos_reg(serial, dummy, sp_reg, baud * 0x10);
1451 	write_mos_reg(serial, dummy, SP_CONTROL_REG, 0x03);
1452 	mos7720_port->shadowMCR = 0x2b;
1453 	write_mos_reg(serial, port_number, MCR, mos7720_port->shadowMCR);
1454 
1455 	/***********************************************
1456 	 *              Set DLL/DLM
1457 	 ***********************************************/
1458 	mos7720_port->shadowLCR = mos7720_port->shadowLCR | UART_LCR_DLAB;
1459 	write_mos_reg(serial, port_number, LCR, mos7720_port->shadowLCR);
1460 	write_mos_reg(serial, port_number, DLL, 0x01);
1461 	write_mos_reg(serial, port_number, DLM, 0x00);
1462 	mos7720_port->shadowLCR = mos7720_port->shadowLCR & ~UART_LCR_DLAB;
1463 	write_mos_reg(serial, port_number, LCR, mos7720_port->shadowLCR);
1464 
1465 	return 0;
1466 }
1467 
1468 /* baud rate information */
1469 struct divisor_table_entry {
1470 	__u32  baudrate;
1471 	__u16  divisor;
1472 };
1473 
1474 /* Define table of divisors for moschip 7720 hardware	   *
1475  * These assume a 3.6864MHz crystal, the standard /16, and *
1476  * MCR.7 = 0.						   */
1477 static struct divisor_table_entry divisor_table[] = {
1478 	{   50,		2304},
1479 	{   110,	1047},	/* 2094.545455 => 230450   => .0217 % over */
1480 	{   134,	857},	/* 1713.011152 => 230398.5 => .00065% under */
1481 	{   150,	768},
1482 	{   300,	384},
1483 	{   600,	192},
1484 	{   1200,	96},
1485 	{   1800,	64},
1486 	{   2400,	48},
1487 	{   4800,	24},
1488 	{   7200,	16},
1489 	{   9600,	12},
1490 	{   19200,	6},
1491 	{   38400,	3},
1492 	{   57600,	2},
1493 	{   115200,	1},
1494 };
1495 
1496 /*****************************************************************************
1497  * calc_baud_rate_divisor
1498  *	this function calculates the proper baud rate divisor for the specified
1499  *	baud rate.
1500  *****************************************************************************/
1501 static int calc_baud_rate_divisor(int baudrate, int *divisor)
1502 {
1503 	int i;
1504 	__u16 custom;
1505 	__u16 round1;
1506 	__u16 round;
1507 
1508 
1509 	dbg("%s - %d", __func__, baudrate);
1510 
1511 	for (i = 0; i < ARRAY_SIZE(divisor_table); i++) {
1512 		if (divisor_table[i].baudrate == baudrate) {
1513 			*divisor = divisor_table[i].divisor;
1514 			return 0;
1515 		}
1516 	}
1517 
1518 	/* After trying for all the standard baud rates    *
1519 	 * Try calculating the divisor for this baud rate  */
1520 	if (baudrate > 75 &&  baudrate < 230400) {
1521 		/* get the divisor */
1522 		custom = (__u16)(230400L  / baudrate);
1523 
1524 		/* Check for round off */
1525 		round1 = (__u16)(2304000L / baudrate);
1526 		round = (__u16)(round1 - (custom * 10));
1527 		if (round > 4)
1528 			custom++;
1529 		*divisor = custom;
1530 
1531 		dbg("Baud %d = %d", baudrate, custom);
1532 		return 0;
1533 	}
1534 
1535 	dbg("Baud calculation Failed...");
1536 	return -EINVAL;
1537 }
1538 
1539 /*
1540  * send_cmd_write_baud_rate
1541  *	this function sends the proper command to change the baud rate of the
1542  *	specified port.
1543  */
1544 static int send_cmd_write_baud_rate(struct moschip_port *mos7720_port,
1545 				    int baudrate)
1546 {
1547 	struct usb_serial_port *port;
1548 	struct usb_serial *serial;
1549 	int divisor;
1550 	int status;
1551 	unsigned char number;
1552 
1553 	if (mos7720_port == NULL)
1554 		return -1;
1555 
1556 	port = mos7720_port->port;
1557 	serial = port->serial;
1558 
1559 	dbg("%s: Entering ..........", __func__);
1560 
1561 	number = port->number - port->serial->minor;
1562 	dbg("%s - port = %d, baud = %d", __func__, port->number, baudrate);
1563 
1564 	/* Calculate the Divisor */
1565 	status = calc_baud_rate_divisor(baudrate, &divisor);
1566 	if (status) {
1567 		dev_err(&port->dev, "%s - bad baud rate\n", __func__);
1568 		return status;
1569 	}
1570 
1571 	/* Enable access to divisor latch */
1572 	mos7720_port->shadowLCR = mos7720_port->shadowLCR | UART_LCR_DLAB;
1573 	write_mos_reg(serial, number, LCR, mos7720_port->shadowLCR);
1574 
1575 	/* Write the divisor */
1576 	write_mos_reg(serial, number, DLL, (__u8)(divisor & 0xff));
1577 	write_mos_reg(serial, number, DLM, (__u8)((divisor & 0xff00) >> 8));
1578 
1579 	/* Disable access to divisor latch */
1580 	mos7720_port->shadowLCR = mos7720_port->shadowLCR & ~UART_LCR_DLAB;
1581 	write_mos_reg(serial, number, LCR, mos7720_port->shadowLCR);
1582 
1583 	return status;
1584 }
1585 
1586 /*
1587  * change_port_settings
1588  *	This routine is called to set the UART on the device to match
1589  *      the specified new settings.
1590  */
1591 static void change_port_settings(struct tty_struct *tty,
1592 				 struct moschip_port *mos7720_port,
1593 				 struct ktermios *old_termios)
1594 {
1595 	struct usb_serial_port *port;
1596 	struct usb_serial *serial;
1597 	int baud;
1598 	unsigned cflag;
1599 	unsigned iflag;
1600 	__u8 mask = 0xff;
1601 	__u8 lData;
1602 	__u8 lParity;
1603 	__u8 lStop;
1604 	int status;
1605 	int port_number;
1606 
1607 	if (mos7720_port == NULL)
1608 		return ;
1609 
1610 	port = mos7720_port->port;
1611 	serial = port->serial;
1612 	port_number = port->number - port->serial->minor;
1613 
1614 	dbg("%s - port %d", __func__, port->number);
1615 
1616 	if (!mos7720_port->open) {
1617 		dbg("%s - port not opened", __func__);
1618 		return;
1619 	}
1620 
1621 	dbg("%s: Entering ..........", __func__);
1622 
1623 	lData = UART_LCR_WLEN8;
1624 	lStop = 0x00;	/* 1 stop bit */
1625 	lParity = 0x00;	/* No parity */
1626 
1627 	cflag = tty->termios->c_cflag;
1628 	iflag = tty->termios->c_iflag;
1629 
1630 	/* Change the number of bits */
1631 	switch (cflag & CSIZE) {
1632 	case CS5:
1633 		lData = UART_LCR_WLEN5;
1634 		mask = 0x1f;
1635 		break;
1636 
1637 	case CS6:
1638 		lData = UART_LCR_WLEN6;
1639 		mask = 0x3f;
1640 		break;
1641 
1642 	case CS7:
1643 		lData = UART_LCR_WLEN7;
1644 		mask = 0x7f;
1645 		break;
1646 	default:
1647 	case CS8:
1648 		lData = UART_LCR_WLEN8;
1649 		break;
1650 	}
1651 
1652 	/* Change the Parity bit */
1653 	if (cflag & PARENB) {
1654 		if (cflag & PARODD) {
1655 			lParity = UART_LCR_PARITY;
1656 			dbg("%s - parity = odd", __func__);
1657 		} else {
1658 			lParity = (UART_LCR_EPAR | UART_LCR_PARITY);
1659 			dbg("%s - parity = even", __func__);
1660 		}
1661 
1662 	} else {
1663 		dbg("%s - parity = none", __func__);
1664 	}
1665 
1666 	if (cflag & CMSPAR)
1667 		lParity = lParity | 0x20;
1668 
1669 	/* Change the Stop bit */
1670 	if (cflag & CSTOPB) {
1671 		lStop = UART_LCR_STOP;
1672 		dbg("%s - stop bits = 2", __func__);
1673 	} else {
1674 		lStop = 0x00;
1675 		dbg("%s - stop bits = 1", __func__);
1676 	}
1677 
1678 #define LCR_BITS_MASK		0x03	/* Mask for bits/char field */
1679 #define LCR_STOP_MASK		0x04	/* Mask for stop bits field */
1680 #define LCR_PAR_MASK		0x38	/* Mask for parity field */
1681 
1682 	/* Update the LCR with the correct value */
1683 	mos7720_port->shadowLCR &=
1684 		~(LCR_BITS_MASK | LCR_STOP_MASK | LCR_PAR_MASK);
1685 	mos7720_port->shadowLCR |= (lData | lParity | lStop);
1686 
1687 
1688 	/* Disable Interrupts */
1689 	write_mos_reg(serial, port_number, IER, 0x00);
1690 	write_mos_reg(serial, port_number, FCR, 0x00);
1691 	write_mos_reg(serial, port_number, FCR, 0xcf);
1692 
1693 	/* Send the updated LCR value to the mos7720 */
1694 	write_mos_reg(serial, port_number, LCR, mos7720_port->shadowLCR);
1695 	mos7720_port->shadowMCR = 0x0b;
1696 	write_mos_reg(serial, port_number, MCR, mos7720_port->shadowMCR);
1697 
1698 	/* set up the MCR register and send it to the mos7720 */
1699 	mos7720_port->shadowMCR = UART_MCR_OUT2;
1700 	if (cflag & CBAUD)
1701 		mos7720_port->shadowMCR |= (UART_MCR_DTR | UART_MCR_RTS);
1702 
1703 	if (cflag & CRTSCTS) {
1704 		mos7720_port->shadowMCR |= (UART_MCR_XONANY);
1705 		/* To set hardware flow control to the specified *
1706 		 * serial port, in SP1/2_CONTROL_REG             */
1707 		if (port->number)
1708 			write_mos_reg(serial, dummy, SP_CONTROL_REG, 0x01);
1709 		else
1710 			write_mos_reg(serial, dummy, SP_CONTROL_REG, 0x02);
1711 
1712 	} else
1713 		mos7720_port->shadowMCR &= ~(UART_MCR_XONANY);
1714 
1715 	write_mos_reg(serial, port_number, MCR, mos7720_port->shadowMCR);
1716 
1717 	/* Determine divisor based on baud rate */
1718 	baud = tty_get_baud_rate(tty);
1719 	if (!baud) {
1720 		/* pick a default, any default... */
1721 		dbg("Picked default baud...");
1722 		baud = 9600;
1723 	}
1724 
1725 	if (baud >= 230400) {
1726 		set_higher_rates(mos7720_port, baud);
1727 		/* Enable Interrupts */
1728 		write_mos_reg(serial, port_number, IER, 0x0c);
1729 		return;
1730 	}
1731 
1732 	dbg("%s - baud rate = %d", __func__, baud);
1733 	status = send_cmd_write_baud_rate(mos7720_port, baud);
1734 	/* FIXME: needs to write actual resulting baud back not just
1735 	   blindly do so */
1736 	if (cflag & CBAUD)
1737 		tty_encode_baud_rate(tty, baud, baud);
1738 	/* Enable Interrupts */
1739 	write_mos_reg(serial, port_number, IER, 0x0c);
1740 
1741 	if (port->read_urb->status != -EINPROGRESS) {
1742 		port->read_urb->dev = serial->dev;
1743 
1744 		status = usb_submit_urb(port->read_urb, GFP_ATOMIC);
1745 		if (status)
1746 			dbg("usb_submit_urb(read bulk) failed, status = %d",
1747 			    status);
1748 	}
1749 	return;
1750 }
1751 
1752 /*
1753  * mos7720_set_termios
1754  *	this function is called by the tty driver when it wants to change the
1755  *	termios structure.
1756  */
1757 static void mos7720_set_termios(struct tty_struct *tty,
1758 		struct usb_serial_port *port, struct ktermios *old_termios)
1759 {
1760 	int status;
1761 	unsigned int cflag;
1762 	struct usb_serial *serial;
1763 	struct moschip_port *mos7720_port;
1764 
1765 	serial = port->serial;
1766 
1767 	mos7720_port = usb_get_serial_port_data(port);
1768 
1769 	if (mos7720_port == NULL)
1770 		return;
1771 
1772 	if (!mos7720_port->open) {
1773 		dbg("%s - port not opened", __func__);
1774 		return;
1775 	}
1776 
1777 	dbg("%s\n", "setting termios - ASPIRE");
1778 
1779 	cflag = tty->termios->c_cflag;
1780 
1781 	dbg("%s - cflag %08x iflag %08x", __func__,
1782 	    tty->termios->c_cflag,
1783 	    RELEVANT_IFLAG(tty->termios->c_iflag));
1784 
1785 	dbg("%s - old cflag %08x old iflag %08x", __func__,
1786 	    old_termios->c_cflag,
1787 	    RELEVANT_IFLAG(old_termios->c_iflag));
1788 
1789 	dbg("%s - port %d", __func__, port->number);
1790 
1791 	/* change the port settings to the new ones specified */
1792 	change_port_settings(tty, mos7720_port, old_termios);
1793 
1794 	if (!port->read_urb) {
1795 		dbg("%s", "URB KILLED !!!!!");
1796 		return;
1797 	}
1798 
1799 	if (port->read_urb->status != -EINPROGRESS) {
1800 		port->read_urb->dev = serial->dev;
1801 		status = usb_submit_urb(port->read_urb, GFP_ATOMIC);
1802 		if (status)
1803 			dbg("usb_submit_urb(read bulk) failed, status = %d",
1804 			    status);
1805 	}
1806 	return;
1807 }
1808 
1809 /*
1810  * get_lsr_info - get line status register info
1811  *
1812  * Purpose: Let user call ioctl() to get info when the UART physically
1813  * 	    is emptied.  On bus types like RS485, the transmitter must
1814  * 	    release the bus after transmitting. This must be done when
1815  * 	    the transmit shift register is empty, not be done when the
1816  * 	    transmit holding register is empty.  This functionality
1817  * 	    allows an RS485 driver to be written in user space.
1818  */
1819 static int get_lsr_info(struct tty_struct *tty,
1820 		struct moschip_port *mos7720_port, unsigned int __user *value)
1821 {
1822 	struct usb_serial_port *port = tty->driver_data;
1823 	unsigned int result = 0;
1824 	unsigned char data = 0;
1825 	int port_number = port->number - port->serial->minor;
1826 	int count;
1827 
1828 	count = mos7720_chars_in_buffer(tty);
1829 	if (count == 0) {
1830 		read_mos_reg(port->serial, port_number, LSR, &data);
1831 		if ((data & (UART_LSR_TEMT | UART_LSR_THRE))
1832 					== (UART_LSR_TEMT | UART_LSR_THRE)) {
1833 			dbg("%s -- Empty", __func__);
1834 			result = TIOCSER_TEMT;
1835 		}
1836 	}
1837 	if (copy_to_user(value, &result, sizeof(int)))
1838 		return -EFAULT;
1839 	return 0;
1840 }
1841 
1842 static int mos7720_tiocmget(struct tty_struct *tty, struct file *file)
1843 {
1844 	struct usb_serial_port *port = tty->driver_data;
1845 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
1846 	unsigned int result = 0;
1847 	unsigned int mcr ;
1848 	unsigned int msr ;
1849 
1850 	dbg("%s - port %d", __func__, port->number);
1851 
1852 	mcr = mos7720_port->shadowMCR;
1853 	msr = mos7720_port->shadowMSR;
1854 
1855 	result = ((mcr & UART_MCR_DTR)  ? TIOCM_DTR : 0)   /* 0x002 */
1856 	  | ((mcr & UART_MCR_RTS)   ? TIOCM_RTS : 0)   /* 0x004 */
1857 	  | ((msr & UART_MSR_CTS)   ? TIOCM_CTS : 0)   /* 0x020 */
1858 	  | ((msr & UART_MSR_DCD)   ? TIOCM_CAR : 0)   /* 0x040 */
1859 	  | ((msr & UART_MSR_RI)    ? TIOCM_RI :  0)   /* 0x080 */
1860 	  | ((msr & UART_MSR_DSR)   ? TIOCM_DSR : 0);  /* 0x100 */
1861 
1862 	dbg("%s -- %x", __func__, result);
1863 
1864 	return result;
1865 }
1866 
1867 static int mos7720_tiocmset(struct tty_struct *tty, struct file *file,
1868 			    unsigned int set, unsigned int clear)
1869 {
1870 	struct usb_serial_port *port = tty->driver_data;
1871 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
1872 	unsigned int mcr ;
1873 	dbg("%s - port %d", __func__, port->number);
1874 	dbg("he was at tiocmget");
1875 
1876 	mcr = mos7720_port->shadowMCR;
1877 
1878 	if (set & TIOCM_RTS)
1879 		mcr |= UART_MCR_RTS;
1880 	if (set & TIOCM_DTR)
1881 		mcr |= UART_MCR_DTR;
1882 	if (set & TIOCM_LOOP)
1883 		mcr |= UART_MCR_LOOP;
1884 
1885 	if (clear & TIOCM_RTS)
1886 		mcr &= ~UART_MCR_RTS;
1887 	if (clear & TIOCM_DTR)
1888 		mcr &= ~UART_MCR_DTR;
1889 	if (clear & TIOCM_LOOP)
1890 		mcr &= ~UART_MCR_LOOP;
1891 
1892 	mos7720_port->shadowMCR = mcr;
1893 	write_mos_reg(port->serial, port->number - port->serial->minor,
1894 		      MCR, mos7720_port->shadowMCR);
1895 
1896 	return 0;
1897 }
1898 
1899 static int set_modem_info(struct moschip_port *mos7720_port, unsigned int cmd,
1900 			  unsigned int __user *value)
1901 {
1902 	unsigned int mcr ;
1903 	unsigned int arg;
1904 
1905 	struct usb_serial_port *port;
1906 
1907 	if (mos7720_port == NULL)
1908 		return -1;
1909 
1910 	port = (struct usb_serial_port *)mos7720_port->port;
1911 	mcr = mos7720_port->shadowMCR;
1912 
1913 	if (copy_from_user(&arg, value, sizeof(int)))
1914 		return -EFAULT;
1915 
1916 	switch (cmd) {
1917 	case TIOCMBIS:
1918 		if (arg & TIOCM_RTS)
1919 			mcr |= UART_MCR_RTS;
1920 		if (arg & TIOCM_DTR)
1921 			mcr |= UART_MCR_RTS;
1922 		if (arg & TIOCM_LOOP)
1923 			mcr |= UART_MCR_LOOP;
1924 		break;
1925 
1926 	case TIOCMBIC:
1927 		if (arg & TIOCM_RTS)
1928 			mcr &= ~UART_MCR_RTS;
1929 		if (arg & TIOCM_DTR)
1930 			mcr &= ~UART_MCR_RTS;
1931 		if (arg & TIOCM_LOOP)
1932 			mcr &= ~UART_MCR_LOOP;
1933 		break;
1934 
1935 	}
1936 
1937 	mos7720_port->shadowMCR = mcr;
1938 	write_mos_reg(port->serial, port->number - port->serial->minor,
1939 		      MCR, mos7720_port->shadowMCR);
1940 
1941 	return 0;
1942 }
1943 
1944 static int get_serial_info(struct moschip_port *mos7720_port,
1945 			   struct serial_struct __user *retinfo)
1946 {
1947 	struct serial_struct tmp;
1948 
1949 	if (!retinfo)
1950 		return -EFAULT;
1951 
1952 	memset(&tmp, 0, sizeof(tmp));
1953 
1954 	tmp.type		= PORT_16550A;
1955 	tmp.line		= mos7720_port->port->serial->minor;
1956 	tmp.port		= mos7720_port->port->number;
1957 	tmp.irq			= 0;
1958 	tmp.flags		= ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
1959 	tmp.xmit_fifo_size	= NUM_URBS * URB_TRANSFER_BUFFER_SIZE;
1960 	tmp.baud_base		= 9600;
1961 	tmp.close_delay		= 5*HZ;
1962 	tmp.closing_wait	= 30*HZ;
1963 
1964 	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
1965 		return -EFAULT;
1966 	return 0;
1967 }
1968 
1969 static int mos7720_ioctl(struct tty_struct *tty, struct file *file,
1970 			 unsigned int cmd, unsigned long arg)
1971 {
1972 	struct usb_serial_port *port = tty->driver_data;
1973 	struct moschip_port *mos7720_port;
1974 	struct async_icount cnow;
1975 	struct async_icount cprev;
1976 	struct serial_icounter_struct icount;
1977 
1978 	mos7720_port = usb_get_serial_port_data(port);
1979 	if (mos7720_port == NULL)
1980 		return -ENODEV;
1981 
1982 	dbg("%s - port %d, cmd = 0x%x", __func__, port->number, cmd);
1983 
1984 	switch (cmd) {
1985 	case TIOCSERGETLSR:
1986 		dbg("%s (%d) TIOCSERGETLSR", __func__,  port->number);
1987 		return get_lsr_info(tty, mos7720_port,
1988 					(unsigned int __user *)arg);
1989 		return 0;
1990 
1991 	/* FIXME: These should be using the mode methods */
1992 	case TIOCMBIS:
1993 	case TIOCMBIC:
1994 		dbg("%s (%d) TIOCMSET/TIOCMBIC/TIOCMSET",
1995 					__func__, port->number);
1996 		return set_modem_info(mos7720_port, cmd,
1997 				      (unsigned int __user *)arg);
1998 
1999 	case TIOCGSERIAL:
2000 		dbg("%s (%d) TIOCGSERIAL", __func__,  port->number);
2001 		return get_serial_info(mos7720_port,
2002 				       (struct serial_struct __user *)arg);
2003 
2004 	case TIOCMIWAIT:
2005 		dbg("%s (%d) TIOCMIWAIT", __func__,  port->number);
2006 		cprev = mos7720_port->icount;
2007 		while (1) {
2008 			if (signal_pending(current))
2009 				return -ERESTARTSYS;
2010 			cnow = mos7720_port->icount;
2011 			if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
2012 			    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
2013 				return -EIO; /* no change => error */
2014 			if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
2015 			    ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
2016 			    ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
2017 			    ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {
2018 				return 0;
2019 			}
2020 			cprev = cnow;
2021 		}
2022 		/* NOTREACHED */
2023 		break;
2024 
2025 	case TIOCGICOUNT:
2026 		cnow = mos7720_port->icount;
2027 
2028 		memset(&icount, 0, sizeof(struct serial_icounter_struct));
2029 
2030 		icount.cts = cnow.cts;
2031 		icount.dsr = cnow.dsr;
2032 		icount.rng = cnow.rng;
2033 		icount.dcd = cnow.dcd;
2034 		icount.rx = cnow.rx;
2035 		icount.tx = cnow.tx;
2036 		icount.frame = cnow.frame;
2037 		icount.overrun = cnow.overrun;
2038 		icount.parity = cnow.parity;
2039 		icount.brk = cnow.brk;
2040 		icount.buf_overrun = cnow.buf_overrun;
2041 
2042 		dbg("%s (%d) TIOCGICOUNT RX=%d, TX=%d", __func__,
2043 		    port->number, icount.rx, icount.tx);
2044 		if (copy_to_user((void __user *)arg, &icount, sizeof(icount)))
2045 			return -EFAULT;
2046 		return 0;
2047 	}
2048 
2049 	return -ENOIOCTLCMD;
2050 }
2051 
2052 static int mos7720_startup(struct usb_serial *serial)
2053 {
2054 	struct moschip_port *mos7720_port;
2055 	struct usb_device *dev;
2056 	int i;
2057 	char data;
2058 	u16 product = le16_to_cpu(serial->dev->descriptor.idProduct);
2059 	int ret_val;
2060 
2061 	dbg("%s: Entering ..........", __func__);
2062 
2063 	if (!serial) {
2064 		dbg("Invalid Handler");
2065 		return -ENODEV;
2066 	}
2067 
2068 	dev = serial->dev;
2069 
2070 	/*
2071 	 * The 7715 uses the first bulk in/out endpoint pair for the parallel
2072 	 * port, and the second for the serial port.  Because the usbserial core
2073 	 * assumes both pairs are serial ports, we must engage in a bit of
2074 	 * subterfuge and swap the pointers for ports 0 and 1 in order to make
2075 	 * port 0 point to the serial port.  However, both moschip devices use a
2076 	 * single interrupt-in endpoint for both ports (as mentioned a little
2077 	 * further down), and this endpoint was assigned to port 0.  So after
2078 	 * the swap, we must copy the interrupt endpoint elements from port 1
2079 	 * (as newly assigned) to port 0, and null out port 1 pointers.
2080 	 */
2081 	if (product == MOSCHIP_DEVICE_ID_7715) {
2082 		struct usb_serial_port *tmp = serial->port[0];
2083 		serial->port[0] = serial->port[1];
2084 		serial->port[1] = tmp;
2085 		serial->port[0]->interrupt_in_urb = tmp->interrupt_in_urb;
2086 		serial->port[0]->interrupt_in_buffer = tmp->interrupt_in_buffer;
2087 		serial->port[0]->interrupt_in_endpointAddress =
2088 			tmp->interrupt_in_endpointAddress;
2089 		serial->port[1]->interrupt_in_urb = NULL;
2090 		serial->port[1]->interrupt_in_buffer = NULL;
2091 	}
2092 
2093 
2094 	/* set up serial port private structures */
2095 	for (i = 0; i < serial->num_ports; ++i) {
2096 		mos7720_port = kzalloc(sizeof(struct moschip_port), GFP_KERNEL);
2097 		if (mos7720_port == NULL) {
2098 			dev_err(&dev->dev, "%s - Out of memory\n", __func__);
2099 			return -ENOMEM;
2100 		}
2101 
2102 		/* Initialize all port interrupt end point to port 0 int
2103 		 * endpoint.  Our device has only one interrupt endpoint
2104 		 * common to all ports */
2105 		serial->port[i]->interrupt_in_endpointAddress =
2106 				serial->port[0]->interrupt_in_endpointAddress;
2107 
2108 		mos7720_port->port = serial->port[i];
2109 		usb_set_serial_port_data(serial->port[i], mos7720_port);
2110 
2111 		dbg("port number is %d", serial->port[i]->number);
2112 		dbg("serial number is %d", serial->minor);
2113 	}
2114 
2115 
2116 	/* setting configuration feature to one */
2117 	usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
2118 			(__u8)0x03, 0x00, 0x01, 0x00, NULL, 0x00, 5*HZ);
2119 
2120 	/* start the interrupt urb */
2121 	ret_val = usb_submit_urb(serial->port[0]->interrupt_in_urb, GFP_KERNEL);
2122 	if (ret_val)
2123 		dev_err(&dev->dev,
2124 			"%s - Error %d submitting control urb\n",
2125 			__func__, ret_val);
2126 
2127 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
2128 	if (product == MOSCHIP_DEVICE_ID_7715) {
2129 		ret_val = mos7715_parport_init(serial);
2130 		if (ret_val < 0)
2131 			return ret_val;
2132 	}
2133 #endif
2134 	/* LSR For Port 1 */
2135 	read_mos_reg(serial, 0, LSR, &data);
2136 	dbg("LSR:%x", data);
2137 
2138 	return 0;
2139 }
2140 
2141 static void mos7720_release(struct usb_serial *serial)
2142 {
2143 	int i;
2144 
2145 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
2146 	/* close the parallel port */
2147 
2148 	if (le16_to_cpu(serial->dev->descriptor.idProduct)
2149 	    == MOSCHIP_DEVICE_ID_7715) {
2150 		struct urbtracker *urbtrack;
2151 		unsigned long flags;
2152 		struct mos7715_parport *mos_parport =
2153 			usb_get_serial_data(serial);
2154 
2155 		/* prevent NULL ptr dereference in port callbacks */
2156 		spin_lock(&release_lock);
2157 		mos_parport->pp->private_data = NULL;
2158 		spin_unlock(&release_lock);
2159 
2160 		/* wait for synchronous usb calls to return */
2161 		if (mos_parport->msg_pending)
2162 			wait_for_completion_timeout(&mos_parport->syncmsg_compl,
2163 						    MOS_WDR_TIMEOUT);
2164 
2165 		parport_remove_port(mos_parport->pp);
2166 		usb_set_serial_data(serial, NULL);
2167 		mos_parport->serial = NULL;
2168 
2169 		/* if tasklet currently scheduled, wait for it to complete */
2170 		tasklet_kill(&mos_parport->urb_tasklet);
2171 
2172 		/* unlink any urbs sent by the tasklet  */
2173 		spin_lock_irqsave(&mos_parport->listlock, flags);
2174 		list_for_each_entry(urbtrack,
2175 				    &mos_parport->active_urbs,
2176 				    urblist_entry)
2177 			usb_unlink_urb(urbtrack->urb);
2178 		spin_unlock_irqrestore(&mos_parport->listlock, flags);
2179 
2180 		kref_put(&mos_parport->ref_count, destroy_mos_parport);
2181 	}
2182 #endif
2183 	/* free private structure allocated for serial port */
2184 	for (i = 0; i < serial->num_ports; ++i)
2185 		kfree(usb_get_serial_port_data(serial->port[i]));
2186 }
2187 
2188 static struct usb_driver usb_driver = {
2189 	.name =		"moschip7720",
2190 	.probe =	usb_serial_probe,
2191 	.disconnect =	usb_serial_disconnect,
2192 	.id_table =	moschip_port_id_table,
2193 	.no_dynamic_id =	1,
2194 };
2195 
2196 static struct usb_serial_driver moschip7720_2port_driver = {
2197 	.driver = {
2198 		.owner =	THIS_MODULE,
2199 		.name =		"moschip7720",
2200 	},
2201 	.description		= "Moschip 2 port adapter",
2202 	.usb_driver		= &usb_driver,
2203 	.id_table		= moschip_port_id_table,
2204 	.calc_num_ports		= mos77xx_calc_num_ports,
2205 	.open			= mos7720_open,
2206 	.close			= mos7720_close,
2207 	.throttle		= mos7720_throttle,
2208 	.unthrottle		= mos7720_unthrottle,
2209 	.probe			= mos77xx_probe,
2210 	.attach			= mos7720_startup,
2211 	.release		= mos7720_release,
2212 	.ioctl			= mos7720_ioctl,
2213 	.tiocmget		= mos7720_tiocmget,
2214 	.tiocmset		= mos7720_tiocmset,
2215 	.set_termios		= mos7720_set_termios,
2216 	.write			= mos7720_write,
2217 	.write_room		= mos7720_write_room,
2218 	.chars_in_buffer	= mos7720_chars_in_buffer,
2219 	.break_ctl		= mos7720_break,
2220 	.read_bulk_callback	= mos7720_bulk_in_callback,
2221 	.read_int_callback	= NULL  /* dynamically assigned in probe() */
2222 };
2223 
2224 static int __init moschip7720_init(void)
2225 {
2226 	int retval;
2227 
2228 	dbg("%s: Entering ..........", __func__);
2229 
2230 	/* Register with the usb serial */
2231 	retval = usb_serial_register(&moschip7720_2port_driver);
2232 	if (retval)
2233 		goto failed_port_device_register;
2234 
2235 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
2236 	       DRIVER_DESC "\n");
2237 
2238 	/* Register with the usb */
2239 	retval = usb_register(&usb_driver);
2240 	if (retval)
2241 		goto failed_usb_register;
2242 
2243 	return 0;
2244 
2245 failed_usb_register:
2246 	usb_serial_deregister(&moschip7720_2port_driver);
2247 
2248 failed_port_device_register:
2249 	return retval;
2250 }
2251 
2252 static void __exit moschip7720_exit(void)
2253 {
2254 	usb_deregister(&usb_driver);
2255 	usb_serial_deregister(&moschip7720_2port_driver);
2256 }
2257 
2258 module_init(moschip7720_init);
2259 module_exit(moschip7720_exit);
2260 
2261 /* Module information */
2262 MODULE_AUTHOR(DRIVER_AUTHOR);
2263 MODULE_DESCRIPTION(DRIVER_DESC);
2264 MODULE_LICENSE("GPL");
2265 
2266 module_param(debug, bool, S_IRUGO | S_IWUSR);
2267 MODULE_PARM_DESC(debug, "Debug enabled or not");
2268