xref: /openbmc/linux/drivers/usb/serial/mos7720.c (revision 505b0877)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * mos7720.c
4  *   Controls the Moschip 7720 usb to dual port serial converter
5  *
6  * Copyright 2006 Moschip Semiconductor Tech. Ltd.
7  *
8  * Developed by:
9  * 	Vijaya Kumar <vijaykumar.gn@gmail.com>
10  *	Ajay Kumar <naanuajay@yahoo.com>
11  *	Gurudeva <ngurudeva@yahoo.com>
12  *
13  * Cleaned up from the original by:
14  *	Greg Kroah-Hartman <gregkh@suse.de>
15  *
16  * Originally based on drivers/usb/serial/io_edgeport.c which is:
17  *	Copyright (C) 2000 Inside Out Networks, All rights reserved.
18  *	Copyright (C) 2001-2002 Greg Kroah-Hartman <greg@kroah.com>
19  */
20 #include <linux/kernel.h>
21 #include <linux/errno.h>
22 #include <linux/slab.h>
23 #include <linux/tty.h>
24 #include <linux/tty_driver.h>
25 #include <linux/tty_flip.h>
26 #include <linux/module.h>
27 #include <linux/spinlock.h>
28 #include <linux/serial.h>
29 #include <linux/serial_reg.h>
30 #include <linux/usb.h>
31 #include <linux/usb/serial.h>
32 #include <linux/uaccess.h>
33 #include <linux/parport.h>
34 
35 #define DRIVER_AUTHOR "Aspire Communications pvt Ltd."
36 #define DRIVER_DESC "Moschip USB Serial Driver"
37 
38 /* default urb timeout */
39 #define MOS_WDR_TIMEOUT	5000
40 
41 #define MOS_MAX_PORT	0x02
42 #define MOS_WRITE	0x0E
43 #define MOS_READ	0x0D
44 
45 /* Interrupt Routines Defines	*/
46 #define SERIAL_IIR_RLS	0x06
47 #define SERIAL_IIR_RDA	0x04
48 #define SERIAL_IIR_CTI	0x0c
49 #define SERIAL_IIR_THR	0x02
50 #define SERIAL_IIR_MS	0x00
51 
52 #define NUM_URBS			16	/* URB Count */
53 #define URB_TRANSFER_BUFFER_SIZE	32	/* URB Size */
54 
55 /* This structure holds all of the local serial port information */
56 struct moschip_port {
57 	__u8	shadowLCR;		/* last LCR value received */
58 	__u8	shadowMCR;		/* last MCR value received */
59 	__u8	shadowMSR;		/* last MSR value received */
60 	char			open;
61 	struct usb_serial_port	*port;	/* loop back to the owner */
62 	struct urb		*write_urb_pool[NUM_URBS];
63 };
64 
65 #define USB_VENDOR_ID_MOSCHIP		0x9710
66 #define MOSCHIP_DEVICE_ID_7720		0x7720
67 #define MOSCHIP_DEVICE_ID_7715		0x7715
68 
69 static const struct usb_device_id id_table[] = {
70 	{ USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7720) },
71 	{ USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7715) },
72 	{ } /* terminating entry */
73 };
74 MODULE_DEVICE_TABLE(usb, id_table);
75 
76 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
77 
78 /* initial values for parport regs */
79 #define DCR_INIT_VAL       0x0c	/* SLCTIN, nINIT */
80 #define ECR_INIT_VAL       0x00	/* SPP mode */
81 
82 struct urbtracker {
83 	struct mos7715_parport  *mos_parport;
84 	struct list_head        urblist_entry;
85 	struct kref             ref_count;
86 	struct urb              *urb;
87 	struct usb_ctrlrequest	*setup;
88 };
89 
90 enum mos7715_pp_modes {
91 	SPP = 0<<5,
92 	PS2 = 1<<5,      /* moschip calls this 'NIBBLE' mode */
93 	PPF = 2<<5,	 /* moschip calls this 'CB-FIFO mode */
94 };
95 
96 struct mos7715_parport {
97 	struct parport          *pp;	       /* back to containing struct */
98 	struct kref             ref_count;     /* to instance of this struct */
99 	struct list_head        deferred_urbs; /* list deferred async urbs */
100 	struct list_head        active_urbs;   /* list async urbs in flight */
101 	spinlock_t              listlock;      /* protects list access */
102 	bool                    msg_pending;   /* usb sync call pending */
103 	struct completion       syncmsg_compl; /* usb sync call completed */
104 	struct tasklet_struct   urb_tasklet;   /* for sending deferred urbs */
105 	struct usb_serial       *serial;       /* back to containing struct */
106 	__u8	                shadowECR;     /* parallel port regs... */
107 	__u8	                shadowDCR;
108 	atomic_t                shadowDSR;     /* updated in int-in callback */
109 };
110 
111 /* lock guards against dereferencing NULL ptr in parport ops callbacks */
112 static DEFINE_SPINLOCK(release_lock);
113 
114 #endif	/* CONFIG_USB_SERIAL_MOS7715_PARPORT */
115 
116 static const unsigned int dummy; /* for clarity in register access fns */
117 
118 enum mos_regs {
119 	MOS7720_THR,		  /* serial port regs */
120 	MOS7720_RHR,
121 	MOS7720_IER,
122 	MOS7720_FCR,
123 	MOS7720_ISR,
124 	MOS7720_LCR,
125 	MOS7720_MCR,
126 	MOS7720_LSR,
127 	MOS7720_MSR,
128 	MOS7720_SPR,
129 	MOS7720_DLL,
130 	MOS7720_DLM,
131 	MOS7720_DPR,		  /* parallel port regs */
132 	MOS7720_DSR,
133 	MOS7720_DCR,
134 	MOS7720_ECR,
135 	MOS7720_SP1_REG,	  /* device control regs */
136 	MOS7720_SP2_REG,	  /* serial port 2 (7720 only) */
137 	MOS7720_PP_REG,
138 	MOS7720_SP_CONTROL_REG,
139 };
140 
141 /*
142  * Return the correct value for the Windex field of the setup packet
143  * for a control endpoint message.  See the 7715 datasheet.
144  */
145 static inline __u16 get_reg_index(enum mos_regs reg)
146 {
147 	static const __u16 mos7715_index_lookup_table[] = {
148 		0x00,		/* MOS7720_THR */
149 		0x00,		/* MOS7720_RHR */
150 		0x01,		/* MOS7720_IER */
151 		0x02,		/* MOS7720_FCR */
152 		0x02,		/* MOS7720_ISR */
153 		0x03,		/* MOS7720_LCR */
154 		0x04,		/* MOS7720_MCR */
155 		0x05,		/* MOS7720_LSR */
156 		0x06,		/* MOS7720_MSR */
157 		0x07,		/* MOS7720_SPR */
158 		0x00,		/* MOS7720_DLL */
159 		0x01,		/* MOS7720_DLM */
160 		0x00,		/* MOS7720_DPR */
161 		0x01,		/* MOS7720_DSR */
162 		0x02,		/* MOS7720_DCR */
163 		0x0a,		/* MOS7720_ECR */
164 		0x01,		/* MOS7720_SP1_REG */
165 		0x02,		/* MOS7720_SP2_REG (7720 only) */
166 		0x04,		/* MOS7720_PP_REG (7715 only) */
167 		0x08,		/* MOS7720_SP_CONTROL_REG */
168 	};
169 	return mos7715_index_lookup_table[reg];
170 }
171 
172 /*
173  * Return the correct value for the upper byte of the Wvalue field of
174  * the setup packet for a control endpoint message.
175  */
176 static inline __u16 get_reg_value(enum mos_regs reg,
177 				  unsigned int serial_portnum)
178 {
179 	if (reg >= MOS7720_SP1_REG)	/* control reg */
180 		return 0x0000;
181 
182 	else if (reg >= MOS7720_DPR)	/* parallel port reg (7715 only) */
183 		return 0x0100;
184 
185 	else			      /* serial port reg */
186 		return (serial_portnum + 2) << 8;
187 }
188 
189 /*
190  * Write data byte to the specified device register.  The data is embedded in
191  * the value field of the setup packet. serial_portnum is ignored for registers
192  * not specific to a particular serial port.
193  */
194 static int write_mos_reg(struct usb_serial *serial, unsigned int serial_portnum,
195 			 enum mos_regs reg, __u8 data)
196 {
197 	struct usb_device *usbdev = serial->dev;
198 	unsigned int pipe = usb_sndctrlpipe(usbdev, 0);
199 	__u8 request = (__u8)0x0e;
200 	__u8 requesttype = (__u8)0x40;
201 	__u16 index = get_reg_index(reg);
202 	__u16 value = get_reg_value(reg, serial_portnum) + data;
203 	int status = usb_control_msg(usbdev, pipe, request, requesttype, value,
204 				     index, NULL, 0, MOS_WDR_TIMEOUT);
205 	if (status < 0)
206 		dev_err(&usbdev->dev,
207 			"mos7720: usb_control_msg() failed: %d\n", status);
208 	return status;
209 }
210 
211 /*
212  * Read data byte from the specified device register.  The data returned by the
213  * device is embedded in the value field of the setup packet.  serial_portnum is
214  * ignored for registers that are not specific to a particular serial port.
215  */
216 static int read_mos_reg(struct usb_serial *serial, unsigned int serial_portnum,
217 			enum mos_regs reg, __u8 *data)
218 {
219 	struct usb_device *usbdev = serial->dev;
220 	unsigned int pipe = usb_rcvctrlpipe(usbdev, 0);
221 	__u8 request = (__u8)0x0d;
222 	__u8 requesttype = (__u8)0xc0;
223 	__u16 index = get_reg_index(reg);
224 	__u16 value = get_reg_value(reg, serial_portnum);
225 	u8 *buf;
226 	int status;
227 
228 	buf = kmalloc(1, GFP_KERNEL);
229 	if (!buf)
230 		return -ENOMEM;
231 
232 	status = usb_control_msg(usbdev, pipe, request, requesttype, value,
233 				     index, buf, 1, MOS_WDR_TIMEOUT);
234 	if (status == 1) {
235 		*data = *buf;
236 	} else {
237 		dev_err(&usbdev->dev,
238 			"mos7720: usb_control_msg() failed: %d\n", status);
239 		if (status >= 0)
240 			status = -EIO;
241 		*data = 0;
242 	}
243 
244 	kfree(buf);
245 
246 	return status;
247 }
248 
249 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
250 
251 static inline int mos7715_change_mode(struct mos7715_parport *mos_parport,
252 				      enum mos7715_pp_modes mode)
253 {
254 	mos_parport->shadowECR = mode;
255 	write_mos_reg(mos_parport->serial, dummy, MOS7720_ECR,
256 		      mos_parport->shadowECR);
257 	return 0;
258 }
259 
260 static void destroy_mos_parport(struct kref *kref)
261 {
262 	struct mos7715_parport *mos_parport =
263 		container_of(kref, struct mos7715_parport, ref_count);
264 
265 	kfree(mos_parport);
266 }
267 
268 static void destroy_urbtracker(struct kref *kref)
269 {
270 	struct urbtracker *urbtrack =
271 		container_of(kref, struct urbtracker, ref_count);
272 	struct mos7715_parport *mos_parport = urbtrack->mos_parport;
273 
274 	usb_free_urb(urbtrack->urb);
275 	kfree(urbtrack->setup);
276 	kfree(urbtrack);
277 	kref_put(&mos_parport->ref_count, destroy_mos_parport);
278 }
279 
280 /*
281  * This runs as a tasklet when sending an urb in a non-blocking parallel
282  * port callback had to be deferred because the disconnect mutex could not be
283  * obtained at the time.
284  */
285 static void send_deferred_urbs(struct tasklet_struct *t)
286 {
287 	int ret_val;
288 	unsigned long flags;
289 	struct mos7715_parport *mos_parport = from_tasklet(mos_parport, t,
290 							   urb_tasklet);
291 	struct urbtracker *urbtrack, *tmp;
292 	struct list_head *cursor, *next;
293 	struct device *dev;
294 
295 	/* if release function ran, game over */
296 	if (unlikely(mos_parport->serial == NULL))
297 		return;
298 
299 	dev = &mos_parport->serial->dev->dev;
300 
301 	/* try again to get the mutex */
302 	if (!mutex_trylock(&mos_parport->serial->disc_mutex)) {
303 		dev_dbg(dev, "%s: rescheduling tasklet\n", __func__);
304 		tasklet_schedule(&mos_parport->urb_tasklet);
305 		return;
306 	}
307 
308 	/* if device disconnected, game over */
309 	if (unlikely(mos_parport->serial->disconnected)) {
310 		mutex_unlock(&mos_parport->serial->disc_mutex);
311 		return;
312 	}
313 
314 	spin_lock_irqsave(&mos_parport->listlock, flags);
315 	if (list_empty(&mos_parport->deferred_urbs)) {
316 		spin_unlock_irqrestore(&mos_parport->listlock, flags);
317 		mutex_unlock(&mos_parport->serial->disc_mutex);
318 		dev_dbg(dev, "%s: deferred_urbs list empty\n", __func__);
319 		return;
320 	}
321 
322 	/* move contents of deferred_urbs list to active_urbs list and submit */
323 	list_for_each_safe(cursor, next, &mos_parport->deferred_urbs)
324 		list_move_tail(cursor, &mos_parport->active_urbs);
325 	list_for_each_entry_safe(urbtrack, tmp, &mos_parport->active_urbs,
326 			    urblist_entry) {
327 		ret_val = usb_submit_urb(urbtrack->urb, GFP_ATOMIC);
328 		dev_dbg(dev, "%s: urb submitted\n", __func__);
329 		if (ret_val) {
330 			dev_err(dev, "usb_submit_urb() failed: %d\n", ret_val);
331 			list_del(&urbtrack->urblist_entry);
332 			kref_put(&urbtrack->ref_count, destroy_urbtracker);
333 		}
334 	}
335 	spin_unlock_irqrestore(&mos_parport->listlock, flags);
336 	mutex_unlock(&mos_parport->serial->disc_mutex);
337 }
338 
339 /* callback for parallel port control urbs submitted asynchronously */
340 static void async_complete(struct urb *urb)
341 {
342 	struct urbtracker *urbtrack = urb->context;
343 	int status = urb->status;
344 	unsigned long flags;
345 
346 	if (unlikely(status))
347 		dev_dbg(&urb->dev->dev, "%s - nonzero urb status received: %d\n", __func__, status);
348 
349 	/* remove the urbtracker from the active_urbs list */
350 	spin_lock_irqsave(&urbtrack->mos_parport->listlock, flags);
351 	list_del(&urbtrack->urblist_entry);
352 	spin_unlock_irqrestore(&urbtrack->mos_parport->listlock, flags);
353 	kref_put(&urbtrack->ref_count, destroy_urbtracker);
354 }
355 
356 static int write_parport_reg_nonblock(struct mos7715_parport *mos_parport,
357 				      enum mos_regs reg, __u8 data)
358 {
359 	struct urbtracker *urbtrack;
360 	int ret_val;
361 	unsigned long flags;
362 	struct usb_serial *serial = mos_parport->serial;
363 	struct usb_device *usbdev = serial->dev;
364 
365 	/* create and initialize the control urb and containing urbtracker */
366 	urbtrack = kmalloc(sizeof(struct urbtracker), GFP_ATOMIC);
367 	if (!urbtrack)
368 		return -ENOMEM;
369 
370 	urbtrack->urb = usb_alloc_urb(0, GFP_ATOMIC);
371 	if (!urbtrack->urb) {
372 		kfree(urbtrack);
373 		return -ENOMEM;
374 	}
375 	urbtrack->setup = kmalloc(sizeof(*urbtrack->setup), GFP_ATOMIC);
376 	if (!urbtrack->setup) {
377 		usb_free_urb(urbtrack->urb);
378 		kfree(urbtrack);
379 		return -ENOMEM;
380 	}
381 	urbtrack->setup->bRequestType = (__u8)0x40;
382 	urbtrack->setup->bRequest = (__u8)0x0e;
383 	urbtrack->setup->wValue = cpu_to_le16(get_reg_value(reg, dummy));
384 	urbtrack->setup->wIndex = cpu_to_le16(get_reg_index(reg));
385 	urbtrack->setup->wLength = 0;
386 	usb_fill_control_urb(urbtrack->urb, usbdev,
387 			     usb_sndctrlpipe(usbdev, 0),
388 			     (unsigned char *)urbtrack->setup,
389 			     NULL, 0, async_complete, urbtrack);
390 	kref_get(&mos_parport->ref_count);
391 	urbtrack->mos_parport = mos_parport;
392 	kref_init(&urbtrack->ref_count);
393 	INIT_LIST_HEAD(&urbtrack->urblist_entry);
394 
395 	/*
396 	 * get the disconnect mutex, or add tracker to the deferred_urbs list
397 	 * and schedule a tasklet to try again later
398 	 */
399 	if (!mutex_trylock(&serial->disc_mutex)) {
400 		spin_lock_irqsave(&mos_parport->listlock, flags);
401 		list_add_tail(&urbtrack->urblist_entry,
402 			      &mos_parport->deferred_urbs);
403 		spin_unlock_irqrestore(&mos_parport->listlock, flags);
404 		tasklet_schedule(&mos_parport->urb_tasklet);
405 		dev_dbg(&usbdev->dev, "tasklet scheduled\n");
406 		return 0;
407 	}
408 
409 	/* bail if device disconnected */
410 	if (serial->disconnected) {
411 		kref_put(&urbtrack->ref_count, destroy_urbtracker);
412 		mutex_unlock(&serial->disc_mutex);
413 		return -ENODEV;
414 	}
415 
416 	/* add the tracker to the active_urbs list and submit */
417 	spin_lock_irqsave(&mos_parport->listlock, flags);
418 	list_add_tail(&urbtrack->urblist_entry, &mos_parport->active_urbs);
419 	spin_unlock_irqrestore(&mos_parport->listlock, flags);
420 	ret_val = usb_submit_urb(urbtrack->urb, GFP_ATOMIC);
421 	mutex_unlock(&serial->disc_mutex);
422 	if (ret_val) {
423 		dev_err(&usbdev->dev,
424 			"%s: submit_urb() failed: %d\n", __func__, ret_val);
425 		spin_lock_irqsave(&mos_parport->listlock, flags);
426 		list_del(&urbtrack->urblist_entry);
427 		spin_unlock_irqrestore(&mos_parport->listlock, flags);
428 		kref_put(&urbtrack->ref_count, destroy_urbtracker);
429 		return ret_val;
430 	}
431 	return 0;
432 }
433 
434 /*
435  * This is the the common top part of all parallel port callback operations that
436  * send synchronous messages to the device.  This implements convoluted locking
437  * that avoids two scenarios: (1) a port operation is called after usbserial
438  * has called our release function, at which point struct mos7715_parport has
439  * been destroyed, and (2) the device has been disconnected, but usbserial has
440  * not called the release function yet because someone has a serial port open.
441  * The shared release_lock prevents the first, and the mutex and disconnected
442  * flag maintained by usbserial covers the second.  We also use the msg_pending
443  * flag to ensure that all synchronous usb message calls have completed before
444  * our release function can return.
445  */
446 static int parport_prologue(struct parport *pp)
447 {
448 	struct mos7715_parport *mos_parport;
449 
450 	spin_lock(&release_lock);
451 	mos_parport = pp->private_data;
452 	if (unlikely(mos_parport == NULL)) {
453 		/* release fn called, port struct destroyed */
454 		spin_unlock(&release_lock);
455 		return -1;
456 	}
457 	mos_parport->msg_pending = true;   /* synch usb call pending */
458 	reinit_completion(&mos_parport->syncmsg_compl);
459 	spin_unlock(&release_lock);
460 
461 	mutex_lock(&mos_parport->serial->disc_mutex);
462 	if (mos_parport->serial->disconnected) {
463 		/* device disconnected */
464 		mutex_unlock(&mos_parport->serial->disc_mutex);
465 		mos_parport->msg_pending = false;
466 		complete(&mos_parport->syncmsg_compl);
467 		return -1;
468 	}
469 
470 	return 0;
471 }
472 
473 /*
474  * This is the common bottom part of all parallel port functions that send
475  * synchronous messages to the device.
476  */
477 static inline void parport_epilogue(struct parport *pp)
478 {
479 	struct mos7715_parport *mos_parport = pp->private_data;
480 	mutex_unlock(&mos_parport->serial->disc_mutex);
481 	mos_parport->msg_pending = false;
482 	complete(&mos_parport->syncmsg_compl);
483 }
484 
485 static void parport_mos7715_write_data(struct parport *pp, unsigned char d)
486 {
487 	struct mos7715_parport *mos_parport = pp->private_data;
488 
489 	if (parport_prologue(pp) < 0)
490 		return;
491 	mos7715_change_mode(mos_parport, SPP);
492 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DPR, (__u8)d);
493 	parport_epilogue(pp);
494 }
495 
496 static unsigned char parport_mos7715_read_data(struct parport *pp)
497 {
498 	struct mos7715_parport *mos_parport = pp->private_data;
499 	unsigned char d;
500 
501 	if (parport_prologue(pp) < 0)
502 		return 0;
503 	read_mos_reg(mos_parport->serial, dummy, MOS7720_DPR, &d);
504 	parport_epilogue(pp);
505 	return d;
506 }
507 
508 static void parport_mos7715_write_control(struct parport *pp, unsigned char d)
509 {
510 	struct mos7715_parport *mos_parport = pp->private_data;
511 	__u8 data;
512 
513 	if (parport_prologue(pp) < 0)
514 		return;
515 	data = ((__u8)d & 0x0f) | (mos_parport->shadowDCR & 0xf0);
516 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR, data);
517 	mos_parport->shadowDCR = data;
518 	parport_epilogue(pp);
519 }
520 
521 static unsigned char parport_mos7715_read_control(struct parport *pp)
522 {
523 	struct mos7715_parport *mos_parport;
524 	__u8 dcr;
525 
526 	spin_lock(&release_lock);
527 	mos_parport = pp->private_data;
528 	if (unlikely(mos_parport == NULL)) {
529 		spin_unlock(&release_lock);
530 		return 0;
531 	}
532 	dcr = mos_parport->shadowDCR & 0x0f;
533 	spin_unlock(&release_lock);
534 	return dcr;
535 }
536 
537 static unsigned char parport_mos7715_frob_control(struct parport *pp,
538 						  unsigned char mask,
539 						  unsigned char val)
540 {
541 	struct mos7715_parport *mos_parport = pp->private_data;
542 	__u8 dcr;
543 
544 	mask &= 0x0f;
545 	val &= 0x0f;
546 	if (parport_prologue(pp) < 0)
547 		return 0;
548 	mos_parport->shadowDCR = (mos_parport->shadowDCR & (~mask)) ^ val;
549 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
550 		      mos_parport->shadowDCR);
551 	dcr = mos_parport->shadowDCR & 0x0f;
552 	parport_epilogue(pp);
553 	return dcr;
554 }
555 
556 static unsigned char parport_mos7715_read_status(struct parport *pp)
557 {
558 	unsigned char status;
559 	struct mos7715_parport *mos_parport;
560 
561 	spin_lock(&release_lock);
562 	mos_parport = pp->private_data;
563 	if (unlikely(mos_parport == NULL)) {	/* release called */
564 		spin_unlock(&release_lock);
565 		return 0;
566 	}
567 	status = atomic_read(&mos_parport->shadowDSR) & 0xf8;
568 	spin_unlock(&release_lock);
569 	return status;
570 }
571 
572 static void parport_mos7715_enable_irq(struct parport *pp)
573 {
574 }
575 
576 static void parport_mos7715_disable_irq(struct parport *pp)
577 {
578 }
579 
580 static void parport_mos7715_data_forward(struct parport *pp)
581 {
582 	struct mos7715_parport *mos_parport = pp->private_data;
583 
584 	if (parport_prologue(pp) < 0)
585 		return;
586 	mos7715_change_mode(mos_parport, PS2);
587 	mos_parport->shadowDCR &=  ~0x20;
588 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
589 		      mos_parport->shadowDCR);
590 	parport_epilogue(pp);
591 }
592 
593 static void parport_mos7715_data_reverse(struct parport *pp)
594 {
595 	struct mos7715_parport *mos_parport = pp->private_data;
596 
597 	if (parport_prologue(pp) < 0)
598 		return;
599 	mos7715_change_mode(mos_parport, PS2);
600 	mos_parport->shadowDCR |= 0x20;
601 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
602 		      mos_parport->shadowDCR);
603 	parport_epilogue(pp);
604 }
605 
606 static void parport_mos7715_init_state(struct pardevice *dev,
607 				       struct parport_state *s)
608 {
609 	s->u.pc.ctr = DCR_INIT_VAL;
610 	s->u.pc.ecr = ECR_INIT_VAL;
611 }
612 
613 /* N.B. Parport core code requires that this function not block */
614 static void parport_mos7715_save_state(struct parport *pp,
615 				       struct parport_state *s)
616 {
617 	struct mos7715_parport *mos_parport;
618 
619 	spin_lock(&release_lock);
620 	mos_parport = pp->private_data;
621 	if (unlikely(mos_parport == NULL)) {	/* release called */
622 		spin_unlock(&release_lock);
623 		return;
624 	}
625 	s->u.pc.ctr = mos_parport->shadowDCR;
626 	s->u.pc.ecr = mos_parport->shadowECR;
627 	spin_unlock(&release_lock);
628 }
629 
630 /* N.B. Parport core code requires that this function not block */
631 static void parport_mos7715_restore_state(struct parport *pp,
632 					  struct parport_state *s)
633 {
634 	struct mos7715_parport *mos_parport;
635 
636 	spin_lock(&release_lock);
637 	mos_parport = pp->private_data;
638 	if (unlikely(mos_parport == NULL)) {	/* release called */
639 		spin_unlock(&release_lock);
640 		return;
641 	}
642 	write_parport_reg_nonblock(mos_parport, MOS7720_DCR,
643 				   mos_parport->shadowDCR);
644 	write_parport_reg_nonblock(mos_parport, MOS7720_ECR,
645 				   mos_parport->shadowECR);
646 	spin_unlock(&release_lock);
647 }
648 
649 static size_t parport_mos7715_write_compat(struct parport *pp,
650 					   const void *buffer,
651 					   size_t len, int flags)
652 {
653 	int retval;
654 	struct mos7715_parport *mos_parport = pp->private_data;
655 	int actual_len;
656 
657 	if (parport_prologue(pp) < 0)
658 		return 0;
659 	mos7715_change_mode(mos_parport, PPF);
660 	retval = usb_bulk_msg(mos_parport->serial->dev,
661 			      usb_sndbulkpipe(mos_parport->serial->dev, 2),
662 			      (void *)buffer, len, &actual_len,
663 			      MOS_WDR_TIMEOUT);
664 	parport_epilogue(pp);
665 	if (retval) {
666 		dev_err(&mos_parport->serial->dev->dev,
667 			"mos7720: usb_bulk_msg() failed: %d\n", retval);
668 		return 0;
669 	}
670 	return actual_len;
671 }
672 
673 static struct parport_operations parport_mos7715_ops = {
674 	.owner =		THIS_MODULE,
675 	.write_data =		parport_mos7715_write_data,
676 	.read_data =		parport_mos7715_read_data,
677 
678 	.write_control =	parport_mos7715_write_control,
679 	.read_control =		parport_mos7715_read_control,
680 	.frob_control =		parport_mos7715_frob_control,
681 
682 	.read_status =		parport_mos7715_read_status,
683 
684 	.enable_irq =		parport_mos7715_enable_irq,
685 	.disable_irq =		parport_mos7715_disable_irq,
686 
687 	.data_forward =		parport_mos7715_data_forward,
688 	.data_reverse =		parport_mos7715_data_reverse,
689 
690 	.init_state =		parport_mos7715_init_state,
691 	.save_state =		parport_mos7715_save_state,
692 	.restore_state =	parport_mos7715_restore_state,
693 
694 	.compat_write_data =	parport_mos7715_write_compat,
695 
696 	.nibble_read_data =	parport_ieee1284_read_nibble,
697 	.byte_read_data =	parport_ieee1284_read_byte,
698 };
699 
700 /*
701  * Allocate and initialize parallel port control struct, initialize
702  * the parallel port hardware device, and register with the parport subsystem.
703  */
704 static int mos7715_parport_init(struct usb_serial *serial)
705 {
706 	struct mos7715_parport *mos_parport;
707 
708 	/* allocate and initialize parallel port control struct */
709 	mos_parport = kzalloc(sizeof(struct mos7715_parport), GFP_KERNEL);
710 	if (!mos_parport)
711 		return -ENOMEM;
712 
713 	mos_parport->msg_pending = false;
714 	kref_init(&mos_parport->ref_count);
715 	spin_lock_init(&mos_parport->listlock);
716 	INIT_LIST_HEAD(&mos_parport->active_urbs);
717 	INIT_LIST_HEAD(&mos_parport->deferred_urbs);
718 	usb_set_serial_data(serial, mos_parport); /* hijack private pointer */
719 	mos_parport->serial = serial;
720 	tasklet_setup(&mos_parport->urb_tasklet, send_deferred_urbs);
721 	init_completion(&mos_parport->syncmsg_compl);
722 
723 	/* cycle parallel port reset bit */
724 	write_mos_reg(mos_parport->serial, dummy, MOS7720_PP_REG, (__u8)0x80);
725 	write_mos_reg(mos_parport->serial, dummy, MOS7720_PP_REG, (__u8)0x00);
726 
727 	/* initialize device registers */
728 	mos_parport->shadowDCR = DCR_INIT_VAL;
729 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
730 		      mos_parport->shadowDCR);
731 	mos_parport->shadowECR = ECR_INIT_VAL;
732 	write_mos_reg(mos_parport->serial, dummy, MOS7720_ECR,
733 		      mos_parport->shadowECR);
734 
735 	/* register with parport core */
736 	mos_parport->pp = parport_register_port(0, PARPORT_IRQ_NONE,
737 						PARPORT_DMA_NONE,
738 						&parport_mos7715_ops);
739 	if (mos_parport->pp == NULL) {
740 		dev_err(&serial->interface->dev,
741 			"Could not register parport\n");
742 		kref_put(&mos_parport->ref_count, destroy_mos_parport);
743 		return -EIO;
744 	}
745 	mos_parport->pp->private_data = mos_parport;
746 	mos_parport->pp->modes = PARPORT_MODE_COMPAT | PARPORT_MODE_PCSPP;
747 	mos_parport->pp->dev = &serial->interface->dev;
748 	parport_announce_port(mos_parport->pp);
749 
750 	return 0;
751 }
752 #endif	/* CONFIG_USB_SERIAL_MOS7715_PARPORT */
753 
754 /*
755  * mos7720_interrupt_callback
756  *	this is the callback function for when we have received data on the
757  *	interrupt endpoint.
758  */
759 static void mos7720_interrupt_callback(struct urb *urb)
760 {
761 	int result;
762 	int length;
763 	int status = urb->status;
764 	struct device *dev = &urb->dev->dev;
765 	__u8 *data;
766 	__u8 sp1;
767 	__u8 sp2;
768 
769 	switch (status) {
770 	case 0:
771 		/* success */
772 		break;
773 	case -ECONNRESET:
774 	case -ENOENT:
775 	case -ESHUTDOWN:
776 		/* this urb is terminated, clean up */
777 		dev_dbg(dev, "%s - urb shutting down with status: %d\n", __func__, status);
778 		return;
779 	default:
780 		dev_dbg(dev, "%s - nonzero urb status received: %d\n", __func__, status);
781 		goto exit;
782 	}
783 
784 	length = urb->actual_length;
785 	data = urb->transfer_buffer;
786 
787 	/* Moschip get 4 bytes
788 	 * Byte 1 IIR Port 1 (port.number is 0)
789 	 * Byte 2 IIR Port 2 (port.number is 1)
790 	 * Byte 3 --------------
791 	 * Byte 4 FIFO status for both */
792 
793 	/* the above description is inverted
794 	 * 	oneukum 2007-03-14 */
795 
796 	if (unlikely(length != 4)) {
797 		dev_dbg(dev, "Wrong data !!!\n");
798 		return;
799 	}
800 
801 	sp1 = data[3];
802 	sp2 = data[2];
803 
804 	if ((sp1 | sp2) & 0x01) {
805 		/* No Interrupt Pending in both the ports */
806 		dev_dbg(dev, "No Interrupt !!!\n");
807 	} else {
808 		switch (sp1 & 0x0f) {
809 		case SERIAL_IIR_RLS:
810 			dev_dbg(dev, "Serial Port 1: Receiver status error or address bit detected in 9-bit mode\n");
811 			break;
812 		case SERIAL_IIR_CTI:
813 			dev_dbg(dev, "Serial Port 1: Receiver time out\n");
814 			break;
815 		case SERIAL_IIR_MS:
816 			/* dev_dbg(dev, "Serial Port 1: Modem status change\n"); */
817 			break;
818 		}
819 
820 		switch (sp2 & 0x0f) {
821 		case SERIAL_IIR_RLS:
822 			dev_dbg(dev, "Serial Port 2: Receiver status error or address bit detected in 9-bit mode\n");
823 			break;
824 		case SERIAL_IIR_CTI:
825 			dev_dbg(dev, "Serial Port 2: Receiver time out\n");
826 			break;
827 		case SERIAL_IIR_MS:
828 			/* dev_dbg(dev, "Serial Port 2: Modem status change\n"); */
829 			break;
830 		}
831 	}
832 
833 exit:
834 	result = usb_submit_urb(urb, GFP_ATOMIC);
835 	if (result)
836 		dev_err(dev, "%s - Error %d submitting control urb\n", __func__, result);
837 }
838 
839 /*
840  * mos7715_interrupt_callback
841  *	this is the 7715's callback function for when we have received data on
842  *	the interrupt endpoint.
843  */
844 static void mos7715_interrupt_callback(struct urb *urb)
845 {
846 	int result;
847 	int length;
848 	int status = urb->status;
849 	struct device *dev = &urb->dev->dev;
850 	__u8 *data;
851 	__u8 iir;
852 
853 	switch (status) {
854 	case 0:
855 		/* success */
856 		break;
857 	case -ECONNRESET:
858 	case -ENOENT:
859 	case -ESHUTDOWN:
860 	case -ENODEV:
861 		/* this urb is terminated, clean up */
862 		dev_dbg(dev, "%s - urb shutting down with status: %d\n", __func__, status);
863 		return;
864 	default:
865 		dev_dbg(dev, "%s - nonzero urb status received: %d\n", __func__, status);
866 		goto exit;
867 	}
868 
869 	length = urb->actual_length;
870 	data = urb->transfer_buffer;
871 
872 	/* Structure of data from 7715 device:
873 	 * Byte 1: IIR serial Port
874 	 * Byte 2: unused
875 	 * Byte 2: DSR parallel port
876 	 * Byte 4: FIFO status for both */
877 
878 	if (unlikely(length != 4)) {
879 		dev_dbg(dev, "Wrong data !!!\n");
880 		return;
881 	}
882 
883 	iir = data[0];
884 	if (!(iir & 0x01)) {	/* serial port interrupt pending */
885 		switch (iir & 0x0f) {
886 		case SERIAL_IIR_RLS:
887 			dev_dbg(dev, "Serial Port: Receiver status error or address bit detected in 9-bit mode\n");
888 			break;
889 		case SERIAL_IIR_CTI:
890 			dev_dbg(dev, "Serial Port: Receiver time out\n");
891 			break;
892 		case SERIAL_IIR_MS:
893 			/* dev_dbg(dev, "Serial Port: Modem status change\n"); */
894 			break;
895 		}
896 	}
897 
898 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
899 	{       /* update local copy of DSR reg */
900 		struct usb_serial_port *port = urb->context;
901 		struct mos7715_parport *mos_parport = port->serial->private;
902 		if (unlikely(mos_parport == NULL))
903 			return;
904 		atomic_set(&mos_parport->shadowDSR, data[2]);
905 	}
906 #endif
907 
908 exit:
909 	result = usb_submit_urb(urb, GFP_ATOMIC);
910 	if (result)
911 		dev_err(dev, "%s - Error %d submitting control urb\n", __func__, result);
912 }
913 
914 /*
915  * mos7720_bulk_in_callback
916  *	this is the callback function for when we have received data on the
917  *	bulk in endpoint.
918  */
919 static void mos7720_bulk_in_callback(struct urb *urb)
920 {
921 	int retval;
922 	unsigned char *data ;
923 	struct usb_serial_port *port;
924 	int status = urb->status;
925 
926 	if (status) {
927 		dev_dbg(&urb->dev->dev, "nonzero read bulk status received: %d\n", status);
928 		return;
929 	}
930 
931 	port = urb->context;
932 
933 	dev_dbg(&port->dev, "Entering...%s\n", __func__);
934 
935 	data = urb->transfer_buffer;
936 
937 	if (urb->actual_length) {
938 		tty_insert_flip_string(&port->port, data, urb->actual_length);
939 		tty_flip_buffer_push(&port->port);
940 	}
941 
942 	if (port->read_urb->status != -EINPROGRESS) {
943 		retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
944 		if (retval)
945 			dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, retval = %d\n", retval);
946 	}
947 }
948 
949 /*
950  * mos7720_bulk_out_data_callback
951  *	this is the callback function for when we have finished sending serial
952  *	data on the bulk out endpoint.
953  */
954 static void mos7720_bulk_out_data_callback(struct urb *urb)
955 {
956 	struct moschip_port *mos7720_port;
957 	int status = urb->status;
958 
959 	if (status) {
960 		dev_dbg(&urb->dev->dev, "nonzero write bulk status received:%d\n", status);
961 		return;
962 	}
963 
964 	mos7720_port = urb->context;
965 	if (!mos7720_port) {
966 		dev_dbg(&urb->dev->dev, "NULL mos7720_port pointer\n");
967 		return ;
968 	}
969 
970 	if (mos7720_port->open)
971 		tty_port_tty_wakeup(&mos7720_port->port->port);
972 }
973 
974 static int mos77xx_calc_num_ports(struct usb_serial *serial,
975 					struct usb_serial_endpoints *epds)
976 {
977 	u16 product = le16_to_cpu(serial->dev->descriptor.idProduct);
978 
979 	if (product == MOSCHIP_DEVICE_ID_7715) {
980 		/*
981 		 * The 7715 uses the first bulk in/out endpoint pair for the
982 		 * parallel port, and the second for the serial port. We swap
983 		 * the endpoint descriptors here so that the the first and
984 		 * only registered port structure uses the serial-port
985 		 * endpoints.
986 		 */
987 		swap(epds->bulk_in[0], epds->bulk_in[1]);
988 		swap(epds->bulk_out[0], epds->bulk_out[1]);
989 
990 		return 1;
991 	}
992 
993 	return 2;
994 }
995 
996 static int mos7720_open(struct tty_struct *tty, struct usb_serial_port *port)
997 {
998 	struct usb_serial *serial;
999 	struct urb *urb;
1000 	struct moschip_port *mos7720_port;
1001 	int response;
1002 	int port_number;
1003 	__u8 data;
1004 	int allocated_urbs = 0;
1005 	int j;
1006 
1007 	serial = port->serial;
1008 
1009 	mos7720_port = usb_get_serial_port_data(port);
1010 	if (mos7720_port == NULL)
1011 		return -ENODEV;
1012 
1013 	usb_clear_halt(serial->dev, port->write_urb->pipe);
1014 	usb_clear_halt(serial->dev, port->read_urb->pipe);
1015 
1016 	/* Initialising the write urb pool */
1017 	for (j = 0; j < NUM_URBS; ++j) {
1018 		urb = usb_alloc_urb(0, GFP_KERNEL);
1019 		mos7720_port->write_urb_pool[j] = urb;
1020 		if (!urb)
1021 			continue;
1022 
1023 		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
1024 					       GFP_KERNEL);
1025 		if (!urb->transfer_buffer) {
1026 			usb_free_urb(mos7720_port->write_urb_pool[j]);
1027 			mos7720_port->write_urb_pool[j] = NULL;
1028 			continue;
1029 		}
1030 		allocated_urbs++;
1031 	}
1032 
1033 	if (!allocated_urbs)
1034 		return -ENOMEM;
1035 
1036 	 /* Initialize MCS7720 -- Write Init values to corresponding Registers
1037 	  *
1038 	  * Register Index
1039 	  * 0 : MOS7720_THR/MOS7720_RHR
1040 	  * 1 : MOS7720_IER
1041 	  * 2 : MOS7720_FCR
1042 	  * 3 : MOS7720_LCR
1043 	  * 4 : MOS7720_MCR
1044 	  * 5 : MOS7720_LSR
1045 	  * 6 : MOS7720_MSR
1046 	  * 7 : MOS7720_SPR
1047 	  *
1048 	  * 0x08 : SP1/2 Control Reg
1049 	  */
1050 	port_number = port->port_number;
1051 	read_mos_reg(serial, port_number, MOS7720_LSR, &data);
1052 
1053 	dev_dbg(&port->dev, "SS::%p LSR:%x\n", mos7720_port, data);
1054 
1055 	write_mos_reg(serial, dummy, MOS7720_SP1_REG, 0x02);
1056 	write_mos_reg(serial, dummy, MOS7720_SP2_REG, 0x02);
1057 
1058 	write_mos_reg(serial, port_number, MOS7720_IER, 0x00);
1059 	write_mos_reg(serial, port_number, MOS7720_FCR, 0x00);
1060 
1061 	write_mos_reg(serial, port_number, MOS7720_FCR, 0xcf);
1062 	mos7720_port->shadowLCR = 0x03;
1063 	write_mos_reg(serial, port_number, MOS7720_LCR,
1064 		      mos7720_port->shadowLCR);
1065 	mos7720_port->shadowMCR = 0x0b;
1066 	write_mos_reg(serial, port_number, MOS7720_MCR,
1067 		      mos7720_port->shadowMCR);
1068 
1069 	write_mos_reg(serial, port_number, MOS7720_SP_CONTROL_REG, 0x00);
1070 	read_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG, &data);
1071 	data = data | (port->port_number + 1);
1072 	write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG, data);
1073 	mos7720_port->shadowLCR = 0x83;
1074 	write_mos_reg(serial, port_number, MOS7720_LCR,
1075 		      mos7720_port->shadowLCR);
1076 	write_mos_reg(serial, port_number, MOS7720_THR, 0x0c);
1077 	write_mos_reg(serial, port_number, MOS7720_IER, 0x00);
1078 	mos7720_port->shadowLCR = 0x03;
1079 	write_mos_reg(serial, port_number, MOS7720_LCR,
1080 		      mos7720_port->shadowLCR);
1081 	write_mos_reg(serial, port_number, MOS7720_IER, 0x0c);
1082 
1083 	response = usb_submit_urb(port->read_urb, GFP_KERNEL);
1084 	if (response)
1085 		dev_err(&port->dev, "%s - Error %d submitting read urb\n",
1086 							__func__, response);
1087 
1088 	/* initialize our port settings */
1089 	mos7720_port->shadowMCR = UART_MCR_OUT2; /* Must set to enable ints! */
1090 
1091 	/* send a open port command */
1092 	mos7720_port->open = 1;
1093 
1094 	return 0;
1095 }
1096 
1097 /*
1098  * mos7720_chars_in_buffer
1099  *	this function is called by the tty driver when it wants to know how many
1100  *	bytes of data we currently have outstanding in the port (data that has
1101  *	been written, but hasn't made it out the port yet)
1102  *	If successful, we return the number of bytes left to be written in the
1103  *	system,
1104  *	Otherwise we return a negative error number.
1105  */
1106 static int mos7720_chars_in_buffer(struct tty_struct *tty)
1107 {
1108 	struct usb_serial_port *port = tty->driver_data;
1109 	int i;
1110 	int chars = 0;
1111 	struct moschip_port *mos7720_port;
1112 
1113 	mos7720_port = usb_get_serial_port_data(port);
1114 	if (mos7720_port == NULL)
1115 		return 0;
1116 
1117 	for (i = 0; i < NUM_URBS; ++i) {
1118 		if (mos7720_port->write_urb_pool[i] &&
1119 		    mos7720_port->write_urb_pool[i]->status == -EINPROGRESS)
1120 			chars += URB_TRANSFER_BUFFER_SIZE;
1121 	}
1122 	dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars);
1123 	return chars;
1124 }
1125 
1126 static void mos7720_close(struct usb_serial_port *port)
1127 {
1128 	struct usb_serial *serial;
1129 	struct moschip_port *mos7720_port;
1130 	int j;
1131 
1132 	serial = port->serial;
1133 
1134 	mos7720_port = usb_get_serial_port_data(port);
1135 	if (mos7720_port == NULL)
1136 		return;
1137 
1138 	for (j = 0; j < NUM_URBS; ++j)
1139 		usb_kill_urb(mos7720_port->write_urb_pool[j]);
1140 
1141 	/* Freeing Write URBs */
1142 	for (j = 0; j < NUM_URBS; ++j) {
1143 		if (mos7720_port->write_urb_pool[j]) {
1144 			kfree(mos7720_port->write_urb_pool[j]->transfer_buffer);
1145 			usb_free_urb(mos7720_port->write_urb_pool[j]);
1146 		}
1147 	}
1148 
1149 	/* While closing port, shutdown all bulk read, write  *
1150 	 * and interrupt read if they exists, otherwise nop   */
1151 	usb_kill_urb(port->write_urb);
1152 	usb_kill_urb(port->read_urb);
1153 
1154 	write_mos_reg(serial, port->port_number, MOS7720_MCR, 0x00);
1155 	write_mos_reg(serial, port->port_number, MOS7720_IER, 0x00);
1156 
1157 	mos7720_port->open = 0;
1158 }
1159 
1160 static void mos7720_break(struct tty_struct *tty, int break_state)
1161 {
1162 	struct usb_serial_port *port = tty->driver_data;
1163 	unsigned char data;
1164 	struct usb_serial *serial;
1165 	struct moschip_port *mos7720_port;
1166 
1167 	serial = port->serial;
1168 
1169 	mos7720_port = usb_get_serial_port_data(port);
1170 	if (mos7720_port == NULL)
1171 		return;
1172 
1173 	if (break_state == -1)
1174 		data = mos7720_port->shadowLCR | UART_LCR_SBC;
1175 	else
1176 		data = mos7720_port->shadowLCR & ~UART_LCR_SBC;
1177 
1178 	mos7720_port->shadowLCR  = data;
1179 	write_mos_reg(serial, port->port_number, MOS7720_LCR,
1180 		      mos7720_port->shadowLCR);
1181 }
1182 
1183 /*
1184  * mos7720_write_room
1185  *	this function is called by the tty driver when it wants to know how many
1186  *	bytes of data we can accept for a specific port.
1187  *	If successful, we return the amount of room that we have for this port
1188  *	Otherwise we return a negative error number.
1189  */
1190 static int mos7720_write_room(struct tty_struct *tty)
1191 {
1192 	struct usb_serial_port *port = tty->driver_data;
1193 	struct moschip_port *mos7720_port;
1194 	int room = 0;
1195 	int i;
1196 
1197 	mos7720_port = usb_get_serial_port_data(port);
1198 	if (mos7720_port == NULL)
1199 		return -ENODEV;
1200 
1201 	/* FIXME: Locking */
1202 	for (i = 0; i < NUM_URBS; ++i) {
1203 		if (mos7720_port->write_urb_pool[i] &&
1204 		    mos7720_port->write_urb_pool[i]->status != -EINPROGRESS)
1205 			room += URB_TRANSFER_BUFFER_SIZE;
1206 	}
1207 
1208 	dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
1209 	return room;
1210 }
1211 
1212 static int mos7720_write(struct tty_struct *tty, struct usb_serial_port *port,
1213 				 const unsigned char *data, int count)
1214 {
1215 	int status;
1216 	int i;
1217 	int bytes_sent = 0;
1218 	int transfer_size;
1219 
1220 	struct moschip_port *mos7720_port;
1221 	struct usb_serial *serial;
1222 	struct urb    *urb;
1223 	const unsigned char *current_position = data;
1224 
1225 	serial = port->serial;
1226 
1227 	mos7720_port = usb_get_serial_port_data(port);
1228 	if (mos7720_port == NULL)
1229 		return -ENODEV;
1230 
1231 	/* try to find a free urb in the list */
1232 	urb = NULL;
1233 
1234 	for (i = 0; i < NUM_URBS; ++i) {
1235 		if (mos7720_port->write_urb_pool[i] &&
1236 		    mos7720_port->write_urb_pool[i]->status != -EINPROGRESS) {
1237 			urb = mos7720_port->write_urb_pool[i];
1238 			dev_dbg(&port->dev, "URB:%d\n", i);
1239 			break;
1240 		}
1241 	}
1242 
1243 	if (urb == NULL) {
1244 		dev_dbg(&port->dev, "%s - no more free urbs\n", __func__);
1245 		goto exit;
1246 	}
1247 
1248 	if (urb->transfer_buffer == NULL) {
1249 		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
1250 					       GFP_ATOMIC);
1251 		if (!urb->transfer_buffer)
1252 			goto exit;
1253 	}
1254 	transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
1255 
1256 	memcpy(urb->transfer_buffer, current_position, transfer_size);
1257 	usb_serial_debug_data(&port->dev, __func__, transfer_size,
1258 			      urb->transfer_buffer);
1259 
1260 	/* fill urb with data and submit  */
1261 	usb_fill_bulk_urb(urb, serial->dev,
1262 			  usb_sndbulkpipe(serial->dev,
1263 					port->bulk_out_endpointAddress),
1264 			  urb->transfer_buffer, transfer_size,
1265 			  mos7720_bulk_out_data_callback, mos7720_port);
1266 
1267 	/* send it down the pipe */
1268 	status = usb_submit_urb(urb, GFP_ATOMIC);
1269 	if (status) {
1270 		dev_err_console(port, "%s - usb_submit_urb(write bulk) failed "
1271 			"with status = %d\n", __func__, status);
1272 		bytes_sent = status;
1273 		goto exit;
1274 	}
1275 	bytes_sent = transfer_size;
1276 
1277 exit:
1278 	return bytes_sent;
1279 }
1280 
1281 static void mos7720_throttle(struct tty_struct *tty)
1282 {
1283 	struct usb_serial_port *port = tty->driver_data;
1284 	struct moschip_port *mos7720_port;
1285 	int status;
1286 
1287 	mos7720_port = usb_get_serial_port_data(port);
1288 
1289 	if (mos7720_port == NULL)
1290 		return;
1291 
1292 	if (!mos7720_port->open) {
1293 		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
1294 		return;
1295 	}
1296 
1297 	/* if we are implementing XON/XOFF, send the stop character */
1298 	if (I_IXOFF(tty)) {
1299 		unsigned char stop_char = STOP_CHAR(tty);
1300 		status = mos7720_write(tty, port, &stop_char, 1);
1301 		if (status <= 0)
1302 			return;
1303 	}
1304 
1305 	/* if we are implementing RTS/CTS, toggle that line */
1306 	if (C_CRTSCTS(tty)) {
1307 		mos7720_port->shadowMCR &= ~UART_MCR_RTS;
1308 		write_mos_reg(port->serial, port->port_number, MOS7720_MCR,
1309 			      mos7720_port->shadowMCR);
1310 	}
1311 }
1312 
1313 static void mos7720_unthrottle(struct tty_struct *tty)
1314 {
1315 	struct usb_serial_port *port = tty->driver_data;
1316 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
1317 	int status;
1318 
1319 	if (mos7720_port == NULL)
1320 		return;
1321 
1322 	if (!mos7720_port->open) {
1323 		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
1324 		return;
1325 	}
1326 
1327 	/* if we are implementing XON/XOFF, send the start character */
1328 	if (I_IXOFF(tty)) {
1329 		unsigned char start_char = START_CHAR(tty);
1330 		status = mos7720_write(tty, port, &start_char, 1);
1331 		if (status <= 0)
1332 			return;
1333 	}
1334 
1335 	/* if we are implementing RTS/CTS, toggle that line */
1336 	if (C_CRTSCTS(tty)) {
1337 		mos7720_port->shadowMCR |= UART_MCR_RTS;
1338 		write_mos_reg(port->serial, port->port_number, MOS7720_MCR,
1339 			      mos7720_port->shadowMCR);
1340 	}
1341 }
1342 
1343 /* FIXME: this function does not work */
1344 static int set_higher_rates(struct moschip_port *mos7720_port,
1345 			    unsigned int baud)
1346 {
1347 	struct usb_serial_port *port;
1348 	struct usb_serial *serial;
1349 	int port_number;
1350 	enum mos_regs sp_reg;
1351 	if (mos7720_port == NULL)
1352 		return -EINVAL;
1353 
1354 	port = mos7720_port->port;
1355 	serial = port->serial;
1356 
1357 	 /***********************************************
1358 	 *      Init Sequence for higher rates
1359 	 ***********************************************/
1360 	dev_dbg(&port->dev, "Sending Setting Commands ..........\n");
1361 	port_number = port->port_number;
1362 
1363 	write_mos_reg(serial, port_number, MOS7720_IER, 0x00);
1364 	write_mos_reg(serial, port_number, MOS7720_FCR, 0x00);
1365 	write_mos_reg(serial, port_number, MOS7720_FCR, 0xcf);
1366 	mos7720_port->shadowMCR = 0x0b;
1367 	write_mos_reg(serial, port_number, MOS7720_MCR,
1368 		      mos7720_port->shadowMCR);
1369 	write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG, 0x00);
1370 
1371 	/***********************************************
1372 	 *              Set for higher rates           *
1373 	 ***********************************************/
1374 	/* writing baud rate verbatum into uart clock field clearly not right */
1375 	if (port_number == 0)
1376 		sp_reg = MOS7720_SP1_REG;
1377 	else
1378 		sp_reg = MOS7720_SP2_REG;
1379 	write_mos_reg(serial, dummy, sp_reg, baud * 0x10);
1380 	write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG, 0x03);
1381 	mos7720_port->shadowMCR = 0x2b;
1382 	write_mos_reg(serial, port_number, MOS7720_MCR,
1383 		      mos7720_port->shadowMCR);
1384 
1385 	/***********************************************
1386 	 *              Set DLL/DLM
1387 	 ***********************************************/
1388 	mos7720_port->shadowLCR = mos7720_port->shadowLCR | UART_LCR_DLAB;
1389 	write_mos_reg(serial, port_number, MOS7720_LCR,
1390 		      mos7720_port->shadowLCR);
1391 	write_mos_reg(serial, port_number, MOS7720_DLL, 0x01);
1392 	write_mos_reg(serial, port_number, MOS7720_DLM, 0x00);
1393 	mos7720_port->shadowLCR = mos7720_port->shadowLCR & ~UART_LCR_DLAB;
1394 	write_mos_reg(serial, port_number, MOS7720_LCR,
1395 		      mos7720_port->shadowLCR);
1396 
1397 	return 0;
1398 }
1399 
1400 /* baud rate information */
1401 struct divisor_table_entry {
1402 	__u32  baudrate;
1403 	__u16  divisor;
1404 };
1405 
1406 /* Define table of divisors for moschip 7720 hardware	   *
1407  * These assume a 3.6864MHz crystal, the standard /16, and *
1408  * MCR.7 = 0.						   */
1409 static const struct divisor_table_entry divisor_table[] = {
1410 	{   50,		2304},
1411 	{   110,	1047},	/* 2094.545455 => 230450   => .0217 % over */
1412 	{   134,	857},	/* 1713.011152 => 230398.5 => .00065% under */
1413 	{   150,	768},
1414 	{   300,	384},
1415 	{   600,	192},
1416 	{   1200,	96},
1417 	{   1800,	64},
1418 	{   2400,	48},
1419 	{   4800,	24},
1420 	{   7200,	16},
1421 	{   9600,	12},
1422 	{   19200,	6},
1423 	{   38400,	3},
1424 	{   57600,	2},
1425 	{   115200,	1},
1426 };
1427 
1428 /*****************************************************************************
1429  * calc_baud_rate_divisor
1430  *	this function calculates the proper baud rate divisor for the specified
1431  *	baud rate.
1432  *****************************************************************************/
1433 static int calc_baud_rate_divisor(struct usb_serial_port *port, int baudrate, int *divisor)
1434 {
1435 	int i;
1436 	__u16 custom;
1437 	__u16 round1;
1438 	__u16 round;
1439 
1440 
1441 	dev_dbg(&port->dev, "%s - %d\n", __func__, baudrate);
1442 
1443 	for (i = 0; i < ARRAY_SIZE(divisor_table); i++) {
1444 		if (divisor_table[i].baudrate == baudrate) {
1445 			*divisor = divisor_table[i].divisor;
1446 			return 0;
1447 		}
1448 	}
1449 
1450 	/* After trying for all the standard baud rates    *
1451 	 * Try calculating the divisor for this baud rate  */
1452 	if (baudrate > 75 &&  baudrate < 230400) {
1453 		/* get the divisor */
1454 		custom = (__u16)(230400L  / baudrate);
1455 
1456 		/* Check for round off */
1457 		round1 = (__u16)(2304000L / baudrate);
1458 		round = (__u16)(round1 - (custom * 10));
1459 		if (round > 4)
1460 			custom++;
1461 		*divisor = custom;
1462 
1463 		dev_dbg(&port->dev, "Baud %d = %d\n", baudrate, custom);
1464 		return 0;
1465 	}
1466 
1467 	dev_dbg(&port->dev, "Baud calculation Failed...\n");
1468 	return -EINVAL;
1469 }
1470 
1471 /*
1472  * send_cmd_write_baud_rate
1473  *	this function sends the proper command to change the baud rate of the
1474  *	specified port.
1475  */
1476 static int send_cmd_write_baud_rate(struct moschip_port *mos7720_port,
1477 				    int baudrate)
1478 {
1479 	struct usb_serial_port *port;
1480 	struct usb_serial *serial;
1481 	int divisor;
1482 	int status;
1483 	unsigned char number;
1484 
1485 	if (mos7720_port == NULL)
1486 		return -1;
1487 
1488 	port = mos7720_port->port;
1489 	serial = port->serial;
1490 
1491 	number = port->port_number;
1492 	dev_dbg(&port->dev, "%s - baud = %d\n", __func__, baudrate);
1493 
1494 	/* Calculate the Divisor */
1495 	status = calc_baud_rate_divisor(port, baudrate, &divisor);
1496 	if (status) {
1497 		dev_err(&port->dev, "%s - bad baud rate\n", __func__);
1498 		return status;
1499 	}
1500 
1501 	/* Enable access to divisor latch */
1502 	mos7720_port->shadowLCR = mos7720_port->shadowLCR | UART_LCR_DLAB;
1503 	write_mos_reg(serial, number, MOS7720_LCR, mos7720_port->shadowLCR);
1504 
1505 	/* Write the divisor */
1506 	write_mos_reg(serial, number, MOS7720_DLL, (__u8)(divisor & 0xff));
1507 	write_mos_reg(serial, number, MOS7720_DLM,
1508 		      (__u8)((divisor & 0xff00) >> 8));
1509 
1510 	/* Disable access to divisor latch */
1511 	mos7720_port->shadowLCR = mos7720_port->shadowLCR & ~UART_LCR_DLAB;
1512 	write_mos_reg(serial, number, MOS7720_LCR, mos7720_port->shadowLCR);
1513 
1514 	return status;
1515 }
1516 
1517 /*
1518  * change_port_settings
1519  *	This routine is called to set the UART on the device to match
1520  *      the specified new settings.
1521  */
1522 static void change_port_settings(struct tty_struct *tty,
1523 				 struct moschip_port *mos7720_port,
1524 				 struct ktermios *old_termios)
1525 {
1526 	struct usb_serial_port *port;
1527 	struct usb_serial *serial;
1528 	int baud;
1529 	unsigned cflag;
1530 	__u8 lData;
1531 	__u8 lParity;
1532 	__u8 lStop;
1533 	int status;
1534 	int port_number;
1535 
1536 	if (mos7720_port == NULL)
1537 		return ;
1538 
1539 	port = mos7720_port->port;
1540 	serial = port->serial;
1541 	port_number = port->port_number;
1542 
1543 	if (!mos7720_port->open) {
1544 		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
1545 		return;
1546 	}
1547 
1548 	lData = UART_LCR_WLEN8;
1549 	lStop = 0x00;	/* 1 stop bit */
1550 	lParity = 0x00;	/* No parity */
1551 
1552 	cflag = tty->termios.c_cflag;
1553 
1554 	/* Change the number of bits */
1555 	switch (cflag & CSIZE) {
1556 	case CS5:
1557 		lData = UART_LCR_WLEN5;
1558 		break;
1559 
1560 	case CS6:
1561 		lData = UART_LCR_WLEN6;
1562 		break;
1563 
1564 	case CS7:
1565 		lData = UART_LCR_WLEN7;
1566 		break;
1567 	default:
1568 	case CS8:
1569 		lData = UART_LCR_WLEN8;
1570 		break;
1571 	}
1572 
1573 	/* Change the Parity bit */
1574 	if (cflag & PARENB) {
1575 		if (cflag & PARODD) {
1576 			lParity = UART_LCR_PARITY;
1577 			dev_dbg(&port->dev, "%s - parity = odd\n", __func__);
1578 		} else {
1579 			lParity = (UART_LCR_EPAR | UART_LCR_PARITY);
1580 			dev_dbg(&port->dev, "%s - parity = even\n", __func__);
1581 		}
1582 
1583 	} else {
1584 		dev_dbg(&port->dev, "%s - parity = none\n", __func__);
1585 	}
1586 
1587 	if (cflag & CMSPAR)
1588 		lParity = lParity | 0x20;
1589 
1590 	/* Change the Stop bit */
1591 	if (cflag & CSTOPB) {
1592 		lStop = UART_LCR_STOP;
1593 		dev_dbg(&port->dev, "%s - stop bits = 2\n", __func__);
1594 	} else {
1595 		lStop = 0x00;
1596 		dev_dbg(&port->dev, "%s - stop bits = 1\n", __func__);
1597 	}
1598 
1599 #define LCR_BITS_MASK		0x03	/* Mask for bits/char field */
1600 #define LCR_STOP_MASK		0x04	/* Mask for stop bits field */
1601 #define LCR_PAR_MASK		0x38	/* Mask for parity field */
1602 
1603 	/* Update the LCR with the correct value */
1604 	mos7720_port->shadowLCR &=
1605 		~(LCR_BITS_MASK | LCR_STOP_MASK | LCR_PAR_MASK);
1606 	mos7720_port->shadowLCR |= (lData | lParity | lStop);
1607 
1608 
1609 	/* Disable Interrupts */
1610 	write_mos_reg(serial, port_number, MOS7720_IER, 0x00);
1611 	write_mos_reg(serial, port_number, MOS7720_FCR, 0x00);
1612 	write_mos_reg(serial, port_number, MOS7720_FCR, 0xcf);
1613 
1614 	/* Send the updated LCR value to the mos7720 */
1615 	write_mos_reg(serial, port_number, MOS7720_LCR,
1616 		      mos7720_port->shadowLCR);
1617 	mos7720_port->shadowMCR = 0x0b;
1618 	write_mos_reg(serial, port_number, MOS7720_MCR,
1619 		      mos7720_port->shadowMCR);
1620 
1621 	/* set up the MCR register and send it to the mos7720 */
1622 	mos7720_port->shadowMCR = UART_MCR_OUT2;
1623 	if (cflag & CBAUD)
1624 		mos7720_port->shadowMCR |= (UART_MCR_DTR | UART_MCR_RTS);
1625 
1626 	if (cflag & CRTSCTS) {
1627 		mos7720_port->shadowMCR |= (UART_MCR_XONANY);
1628 		/* To set hardware flow control to the specified *
1629 		 * serial port, in SP1/2_CONTROL_REG             */
1630 		if (port_number)
1631 			write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG,
1632 				      0x01);
1633 		else
1634 			write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG,
1635 				      0x02);
1636 
1637 	} else
1638 		mos7720_port->shadowMCR &= ~(UART_MCR_XONANY);
1639 
1640 	write_mos_reg(serial, port_number, MOS7720_MCR,
1641 		      mos7720_port->shadowMCR);
1642 
1643 	/* Determine divisor based on baud rate */
1644 	baud = tty_get_baud_rate(tty);
1645 	if (!baud) {
1646 		/* pick a default, any default... */
1647 		dev_dbg(&port->dev, "Picked default baud...\n");
1648 		baud = 9600;
1649 	}
1650 
1651 	if (baud >= 230400) {
1652 		set_higher_rates(mos7720_port, baud);
1653 		/* Enable Interrupts */
1654 		write_mos_reg(serial, port_number, MOS7720_IER, 0x0c);
1655 		return;
1656 	}
1657 
1658 	dev_dbg(&port->dev, "%s - baud rate = %d\n", __func__, baud);
1659 	status = send_cmd_write_baud_rate(mos7720_port, baud);
1660 	/* FIXME: needs to write actual resulting baud back not just
1661 	   blindly do so */
1662 	if (cflag & CBAUD)
1663 		tty_encode_baud_rate(tty, baud, baud);
1664 	/* Enable Interrupts */
1665 	write_mos_reg(serial, port_number, MOS7720_IER, 0x0c);
1666 
1667 	if (port->read_urb->status != -EINPROGRESS) {
1668 		status = usb_submit_urb(port->read_urb, GFP_KERNEL);
1669 		if (status)
1670 			dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, status = %d\n", status);
1671 	}
1672 }
1673 
1674 /*
1675  * mos7720_set_termios
1676  *	this function is called by the tty driver when it wants to change the
1677  *	termios structure.
1678  */
1679 static void mos7720_set_termios(struct tty_struct *tty,
1680 		struct usb_serial_port *port, struct ktermios *old_termios)
1681 {
1682 	int status;
1683 	struct moschip_port *mos7720_port;
1684 
1685 	mos7720_port = usb_get_serial_port_data(port);
1686 
1687 	if (mos7720_port == NULL)
1688 		return;
1689 
1690 	if (!mos7720_port->open) {
1691 		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
1692 		return;
1693 	}
1694 
1695 	/* change the port settings to the new ones specified */
1696 	change_port_settings(tty, mos7720_port, old_termios);
1697 
1698 	if (port->read_urb->status != -EINPROGRESS) {
1699 		status = usb_submit_urb(port->read_urb, GFP_KERNEL);
1700 		if (status)
1701 			dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, status = %d\n", status);
1702 	}
1703 }
1704 
1705 /*
1706  * get_lsr_info - get line status register info
1707  *
1708  * Purpose: Let user call ioctl() to get info when the UART physically
1709  * 	    is emptied.  On bus types like RS485, the transmitter must
1710  * 	    release the bus after transmitting. This must be done when
1711  * 	    the transmit shift register is empty, not be done when the
1712  * 	    transmit holding register is empty.  This functionality
1713  * 	    allows an RS485 driver to be written in user space.
1714  */
1715 static int get_lsr_info(struct tty_struct *tty,
1716 		struct moschip_port *mos7720_port, unsigned int __user *value)
1717 {
1718 	struct usb_serial_port *port = tty->driver_data;
1719 	unsigned int result = 0;
1720 	unsigned char data = 0;
1721 	int port_number = port->port_number;
1722 	int count;
1723 
1724 	count = mos7720_chars_in_buffer(tty);
1725 	if (count == 0) {
1726 		read_mos_reg(port->serial, port_number, MOS7720_LSR, &data);
1727 		if ((data & (UART_LSR_TEMT | UART_LSR_THRE))
1728 					== (UART_LSR_TEMT | UART_LSR_THRE)) {
1729 			dev_dbg(&port->dev, "%s -- Empty\n", __func__);
1730 			result = TIOCSER_TEMT;
1731 		}
1732 	}
1733 	if (copy_to_user(value, &result, sizeof(int)))
1734 		return -EFAULT;
1735 	return 0;
1736 }
1737 
1738 static int mos7720_tiocmget(struct tty_struct *tty)
1739 {
1740 	struct usb_serial_port *port = tty->driver_data;
1741 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
1742 	unsigned int result = 0;
1743 	unsigned int mcr ;
1744 	unsigned int msr ;
1745 
1746 	mcr = mos7720_port->shadowMCR;
1747 	msr = mos7720_port->shadowMSR;
1748 
1749 	result = ((mcr & UART_MCR_DTR)  ? TIOCM_DTR : 0)   /* 0x002 */
1750 	  | ((mcr & UART_MCR_RTS)   ? TIOCM_RTS : 0)   /* 0x004 */
1751 	  | ((msr & UART_MSR_CTS)   ? TIOCM_CTS : 0)   /* 0x020 */
1752 	  | ((msr & UART_MSR_DCD)   ? TIOCM_CAR : 0)   /* 0x040 */
1753 	  | ((msr & UART_MSR_RI)    ? TIOCM_RI :  0)   /* 0x080 */
1754 	  | ((msr & UART_MSR_DSR)   ? TIOCM_DSR : 0);  /* 0x100 */
1755 
1756 	return result;
1757 }
1758 
1759 static int mos7720_tiocmset(struct tty_struct *tty,
1760 			    unsigned int set, unsigned int clear)
1761 {
1762 	struct usb_serial_port *port = tty->driver_data;
1763 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
1764 	unsigned int mcr ;
1765 
1766 	mcr = mos7720_port->shadowMCR;
1767 
1768 	if (set & TIOCM_RTS)
1769 		mcr |= UART_MCR_RTS;
1770 	if (set & TIOCM_DTR)
1771 		mcr |= UART_MCR_DTR;
1772 	if (set & TIOCM_LOOP)
1773 		mcr |= UART_MCR_LOOP;
1774 
1775 	if (clear & TIOCM_RTS)
1776 		mcr &= ~UART_MCR_RTS;
1777 	if (clear & TIOCM_DTR)
1778 		mcr &= ~UART_MCR_DTR;
1779 	if (clear & TIOCM_LOOP)
1780 		mcr &= ~UART_MCR_LOOP;
1781 
1782 	mos7720_port->shadowMCR = mcr;
1783 	write_mos_reg(port->serial, port->port_number, MOS7720_MCR,
1784 		      mos7720_port->shadowMCR);
1785 
1786 	return 0;
1787 }
1788 
1789 static int get_serial_info(struct tty_struct *tty,
1790 			   struct serial_struct *ss)
1791 {
1792 	struct usb_serial_port *port = tty->driver_data;
1793 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
1794 
1795 	ss->type		= PORT_16550A;
1796 	ss->line		= mos7720_port->port->minor;
1797 	ss->port		= mos7720_port->port->port_number;
1798 	ss->irq			= 0;
1799 	ss->xmit_fifo_size	= NUM_URBS * URB_TRANSFER_BUFFER_SIZE;
1800 	ss->baud_base		= 9600;
1801 	ss->close_delay		= 5*HZ;
1802 	ss->closing_wait	= 30*HZ;
1803 	return 0;
1804 }
1805 
1806 static int mos7720_ioctl(struct tty_struct *tty,
1807 			 unsigned int cmd, unsigned long arg)
1808 {
1809 	struct usb_serial_port *port = tty->driver_data;
1810 	struct moschip_port *mos7720_port;
1811 
1812 	mos7720_port = usb_get_serial_port_data(port);
1813 	if (mos7720_port == NULL)
1814 		return -ENODEV;
1815 
1816 	switch (cmd) {
1817 	case TIOCSERGETLSR:
1818 		dev_dbg(&port->dev, "%s TIOCSERGETLSR\n", __func__);
1819 		return get_lsr_info(tty, mos7720_port,
1820 					(unsigned int __user *)arg);
1821 	}
1822 
1823 	return -ENOIOCTLCMD;
1824 }
1825 
1826 static int mos7720_startup(struct usb_serial *serial)
1827 {
1828 	struct usb_device *dev;
1829 	char data;
1830 	u16 product;
1831 	int ret_val;
1832 
1833 	product = le16_to_cpu(serial->dev->descriptor.idProduct);
1834 	dev = serial->dev;
1835 
1836 	if (product == MOSCHIP_DEVICE_ID_7715) {
1837 		struct urb *urb = serial->port[0]->interrupt_in_urb;
1838 
1839 		urb->complete = mos7715_interrupt_callback;
1840 
1841 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
1842 		ret_val = mos7715_parport_init(serial);
1843 		if (ret_val < 0)
1844 			return ret_val;
1845 #endif
1846 	}
1847 	/* start the interrupt urb */
1848 	ret_val = usb_submit_urb(serial->port[0]->interrupt_in_urb, GFP_KERNEL);
1849 	if (ret_val) {
1850 		dev_err(&dev->dev, "failed to submit interrupt urb: %d\n",
1851 			ret_val);
1852 	}
1853 
1854 	/* LSR For Port 1 */
1855 	read_mos_reg(serial, 0, MOS7720_LSR, &data);
1856 	dev_dbg(&dev->dev, "LSR:%x\n", data);
1857 
1858 	return 0;
1859 }
1860 
1861 static void mos7720_release(struct usb_serial *serial)
1862 {
1863 	usb_kill_urb(serial->port[0]->interrupt_in_urb);
1864 
1865 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
1866 	/* close the parallel port */
1867 
1868 	if (le16_to_cpu(serial->dev->descriptor.idProduct)
1869 	    == MOSCHIP_DEVICE_ID_7715) {
1870 		struct urbtracker *urbtrack;
1871 		unsigned long flags;
1872 		struct mos7715_parport *mos_parport =
1873 			usb_get_serial_data(serial);
1874 
1875 		/* prevent NULL ptr dereference in port callbacks */
1876 		spin_lock(&release_lock);
1877 		mos_parport->pp->private_data = NULL;
1878 		spin_unlock(&release_lock);
1879 
1880 		/* wait for synchronous usb calls to return */
1881 		if (mos_parport->msg_pending)
1882 			wait_for_completion_timeout(&mos_parport->syncmsg_compl,
1883 					    msecs_to_jiffies(MOS_WDR_TIMEOUT));
1884 
1885 		parport_remove_port(mos_parport->pp);
1886 		usb_set_serial_data(serial, NULL);
1887 		mos_parport->serial = NULL;
1888 
1889 		/* if tasklet currently scheduled, wait for it to complete */
1890 		tasklet_kill(&mos_parport->urb_tasklet);
1891 
1892 		/* unlink any urbs sent by the tasklet  */
1893 		spin_lock_irqsave(&mos_parport->listlock, flags);
1894 		list_for_each_entry(urbtrack,
1895 				    &mos_parport->active_urbs,
1896 				    urblist_entry)
1897 			usb_unlink_urb(urbtrack->urb);
1898 		spin_unlock_irqrestore(&mos_parport->listlock, flags);
1899 		parport_del_port(mos_parport->pp);
1900 
1901 		kref_put(&mos_parport->ref_count, destroy_mos_parport);
1902 	}
1903 #endif
1904 }
1905 
1906 static int mos7720_port_probe(struct usb_serial_port *port)
1907 {
1908 	struct moschip_port *mos7720_port;
1909 
1910 	mos7720_port = kzalloc(sizeof(*mos7720_port), GFP_KERNEL);
1911 	if (!mos7720_port)
1912 		return -ENOMEM;
1913 
1914 	mos7720_port->port = port;
1915 
1916 	usb_set_serial_port_data(port, mos7720_port);
1917 
1918 	return 0;
1919 }
1920 
1921 static int mos7720_port_remove(struct usb_serial_port *port)
1922 {
1923 	struct moschip_port *mos7720_port;
1924 
1925 	mos7720_port = usb_get_serial_port_data(port);
1926 	kfree(mos7720_port);
1927 
1928 	return 0;
1929 }
1930 
1931 static struct usb_serial_driver moschip7720_2port_driver = {
1932 	.driver = {
1933 		.owner =	THIS_MODULE,
1934 		.name =		"moschip7720",
1935 	},
1936 	.description		= "Moschip 2 port adapter",
1937 	.id_table		= id_table,
1938 	.num_bulk_in		= 2,
1939 	.num_bulk_out		= 2,
1940 	.num_interrupt_in	= 1,
1941 	.calc_num_ports		= mos77xx_calc_num_ports,
1942 	.open			= mos7720_open,
1943 	.close			= mos7720_close,
1944 	.throttle		= mos7720_throttle,
1945 	.unthrottle		= mos7720_unthrottle,
1946 	.attach			= mos7720_startup,
1947 	.release		= mos7720_release,
1948 	.port_probe		= mos7720_port_probe,
1949 	.port_remove		= mos7720_port_remove,
1950 	.ioctl			= mos7720_ioctl,
1951 	.tiocmget		= mos7720_tiocmget,
1952 	.tiocmset		= mos7720_tiocmset,
1953 	.get_serial		= get_serial_info,
1954 	.set_termios		= mos7720_set_termios,
1955 	.write			= mos7720_write,
1956 	.write_room		= mos7720_write_room,
1957 	.chars_in_buffer	= mos7720_chars_in_buffer,
1958 	.break_ctl		= mos7720_break,
1959 	.read_bulk_callback	= mos7720_bulk_in_callback,
1960 	.read_int_callback	= mos7720_interrupt_callback,
1961 };
1962 
1963 static struct usb_serial_driver * const serial_drivers[] = {
1964 	&moschip7720_2port_driver, NULL
1965 };
1966 
1967 module_usb_serial_driver(serial_drivers, id_table);
1968 
1969 MODULE_AUTHOR(DRIVER_AUTHOR);
1970 MODULE_DESCRIPTION(DRIVER_DESC);
1971 MODULE_LICENSE("GPL v2");
1972