xref: /openbmc/linux/drivers/usb/serial/mos7720.c (revision a06c488d)
1 /*
2  * mos7720.c
3  *   Controls the Moschip 7720 usb to dual port serial converter
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/slab.h>
26 #include <linux/tty.h>
27 #include <linux/tty_driver.h>
28 #include <linux/tty_flip.h>
29 #include <linux/module.h>
30 #include <linux/spinlock.h>
31 #include <linux/serial.h>
32 #include <linux/serial_reg.h>
33 #include <linux/usb.h>
34 #include <linux/usb/serial.h>
35 #include <linux/uaccess.h>
36 #include <linux/parport.h>
37 
38 #define DRIVER_AUTHOR "Aspire Communications pvt Ltd."
39 #define DRIVER_DESC "Moschip USB Serial Driver"
40 
41 /* default urb timeout */
42 #define MOS_WDR_TIMEOUT	5000
43 
44 #define MOS_MAX_PORT	0x02
45 #define MOS_WRITE	0x0E
46 #define MOS_READ	0x0D
47 
48 /* Interrupt Routines Defines	*/
49 #define SERIAL_IIR_RLS	0x06
50 #define SERIAL_IIR_RDA	0x04
51 #define SERIAL_IIR_CTI	0x0c
52 #define SERIAL_IIR_THR	0x02
53 #define SERIAL_IIR_MS	0x00
54 
55 #define NUM_URBS			16	/* URB Count */
56 #define URB_TRANSFER_BUFFER_SIZE	32	/* URB Size */
57 
58 /* This structure holds all of the local serial port information */
59 struct moschip_port {
60 	__u8	shadowLCR;		/* last LCR value received */
61 	__u8	shadowMCR;		/* last MCR value received */
62 	__u8	shadowMSR;		/* last MSR value received */
63 	char			open;
64 	struct usb_serial_port	*port;	/* loop back to the owner */
65 	struct urb		*write_urb_pool[NUM_URBS];
66 };
67 
68 static struct usb_serial_driver moschip7720_2port_driver;
69 
70 #define USB_VENDOR_ID_MOSCHIP		0x9710
71 #define MOSCHIP_DEVICE_ID_7720		0x7720
72 #define MOSCHIP_DEVICE_ID_7715		0x7715
73 
74 static const struct usb_device_id id_table[] = {
75 	{ USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7720) },
76 	{ USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7715) },
77 	{ } /* terminating entry */
78 };
79 MODULE_DEVICE_TABLE(usb, id_table);
80 
81 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
82 
83 /* initial values for parport regs */
84 #define DCR_INIT_VAL       0x0c	/* SLCTIN, nINIT */
85 #define ECR_INIT_VAL       0x00	/* SPP mode */
86 
87 struct urbtracker {
88 	struct mos7715_parport  *mos_parport;
89 	struct list_head        urblist_entry;
90 	struct kref             ref_count;
91 	struct urb              *urb;
92 	struct usb_ctrlrequest	*setup;
93 };
94 
95 enum mos7715_pp_modes {
96 	SPP = 0<<5,
97 	PS2 = 1<<5,      /* moschip calls this 'NIBBLE' mode */
98 	PPF = 2<<5,	 /* moschip calls this 'CB-FIFO mode */
99 };
100 
101 struct mos7715_parport {
102 	struct parport          *pp;	       /* back to containing struct */
103 	struct kref             ref_count;     /* to instance of this struct */
104 	struct list_head        deferred_urbs; /* list deferred async urbs */
105 	struct list_head        active_urbs;   /* list async urbs in flight */
106 	spinlock_t              listlock;      /* protects list access */
107 	bool                    msg_pending;   /* usb sync call pending */
108 	struct completion       syncmsg_compl; /* usb sync call completed */
109 	struct tasklet_struct   urb_tasklet;   /* for sending deferred urbs */
110 	struct usb_serial       *serial;       /* back to containing struct */
111 	__u8	                shadowECR;     /* parallel port regs... */
112 	__u8	                shadowDCR;
113 	atomic_t                shadowDSR;     /* updated in int-in callback */
114 };
115 
116 /* lock guards against dereferencing NULL ptr in parport ops callbacks */
117 static DEFINE_SPINLOCK(release_lock);
118 
119 #endif	/* CONFIG_USB_SERIAL_MOS7715_PARPORT */
120 
121 static const unsigned int dummy; /* for clarity in register access fns */
122 
123 enum mos_regs {
124 	MOS7720_THR,		  /* serial port regs */
125 	MOS7720_RHR,
126 	MOS7720_IER,
127 	MOS7720_FCR,
128 	MOS7720_ISR,
129 	MOS7720_LCR,
130 	MOS7720_MCR,
131 	MOS7720_LSR,
132 	MOS7720_MSR,
133 	MOS7720_SPR,
134 	MOS7720_DLL,
135 	MOS7720_DLM,
136 	MOS7720_DPR,		  /* parallel port regs */
137 	MOS7720_DSR,
138 	MOS7720_DCR,
139 	MOS7720_ECR,
140 	MOS7720_SP1_REG,	  /* device control regs */
141 	MOS7720_SP2_REG,	  /* serial port 2 (7720 only) */
142 	MOS7720_PP_REG,
143 	MOS7720_SP_CONTROL_REG,
144 };
145 
146 /*
147  * Return the correct value for the Windex field of the setup packet
148  * for a control endpoint message.  See the 7715 datasheet.
149  */
150 static inline __u16 get_reg_index(enum mos_regs reg)
151 {
152 	static const __u16 mos7715_index_lookup_table[] = {
153 		0x00,		/* MOS7720_THR */
154 		0x00,		/* MOS7720_RHR */
155 		0x01,		/* MOS7720_IER */
156 		0x02,		/* MOS7720_FCR */
157 		0x02,		/* MOS7720_ISR */
158 		0x03,		/* MOS7720_LCR */
159 		0x04,		/* MOS7720_MCR */
160 		0x05,		/* MOS7720_LSR */
161 		0x06,		/* MOS7720_MSR */
162 		0x07,		/* MOS7720_SPR */
163 		0x00,		/* MOS7720_DLL */
164 		0x01,		/* MOS7720_DLM */
165 		0x00,		/* MOS7720_DPR */
166 		0x01,		/* MOS7720_DSR */
167 		0x02,		/* MOS7720_DCR */
168 		0x0a,		/* MOS7720_ECR */
169 		0x01,		/* MOS7720_SP1_REG */
170 		0x02,		/* MOS7720_SP2_REG (7720 only) */
171 		0x04,		/* MOS7720_PP_REG (7715 only) */
172 		0x08,		/* MOS7720_SP_CONTROL_REG */
173 	};
174 	return mos7715_index_lookup_table[reg];
175 }
176 
177 /*
178  * Return the correct value for the upper byte of the Wvalue field of
179  * the setup packet for a control endpoint message.
180  */
181 static inline __u16 get_reg_value(enum mos_regs reg,
182 				  unsigned int serial_portnum)
183 {
184 	if (reg >= MOS7720_SP1_REG)	/* control reg */
185 		return 0x0000;
186 
187 	else if (reg >= MOS7720_DPR)	/* parallel port reg (7715 only) */
188 		return 0x0100;
189 
190 	else			      /* serial port reg */
191 		return (serial_portnum + 2) << 8;
192 }
193 
194 /*
195  * Write data byte to the specified device register.  The data is embedded in
196  * the value field of the setup packet. serial_portnum is ignored for registers
197  * not specific to a particular serial port.
198  */
199 static int write_mos_reg(struct usb_serial *serial, unsigned int serial_portnum,
200 			 enum mos_regs reg, __u8 data)
201 {
202 	struct usb_device *usbdev = serial->dev;
203 	unsigned int pipe = usb_sndctrlpipe(usbdev, 0);
204 	__u8 request = (__u8)0x0e;
205 	__u8 requesttype = (__u8)0x40;
206 	__u16 index = get_reg_index(reg);
207 	__u16 value = get_reg_value(reg, serial_portnum) + data;
208 	int status = usb_control_msg(usbdev, pipe, request, requesttype, value,
209 				     index, NULL, 0, MOS_WDR_TIMEOUT);
210 	if (status < 0)
211 		dev_err(&usbdev->dev,
212 			"mos7720: usb_control_msg() failed: %d\n", status);
213 	return status;
214 }
215 
216 /*
217  * Read data byte from the specified device register.  The data returned by the
218  * device is embedded in the value field of the setup packet.  serial_portnum is
219  * ignored for registers that are not specific to a particular serial port.
220  */
221 static int read_mos_reg(struct usb_serial *serial, unsigned int serial_portnum,
222 			enum mos_regs reg, __u8 *data)
223 {
224 	struct usb_device *usbdev = serial->dev;
225 	unsigned int pipe = usb_rcvctrlpipe(usbdev, 0);
226 	__u8 request = (__u8)0x0d;
227 	__u8 requesttype = (__u8)0xc0;
228 	__u16 index = get_reg_index(reg);
229 	__u16 value = get_reg_value(reg, serial_portnum);
230 	u8 *buf;
231 	int status;
232 
233 	buf = kmalloc(1, GFP_KERNEL);
234 	if (!buf)
235 		return -ENOMEM;
236 
237 	status = usb_control_msg(usbdev, pipe, request, requesttype, value,
238 				     index, buf, 1, MOS_WDR_TIMEOUT);
239 	if (status == 1)
240 		*data = *buf;
241 	else if (status < 0)
242 		dev_err(&usbdev->dev,
243 			"mos7720: usb_control_msg() failed: %d\n", status);
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(unsigned long _mos_parport)
286 {
287 	int ret_val;
288 	unsigned long flags;
289 	struct mos7715_parport *mos_parport = (void *)_mos_parport;
290 	struct urbtracker *urbtrack, *tmp;
291 	struct list_head *cursor, *next;
292 	struct device *dev;
293 
294 	/* if release function ran, game over */
295 	if (unlikely(mos_parport->serial == NULL))
296 		return;
297 
298 	dev = &mos_parport->serial->dev->dev;
299 
300 	/* try again to get the mutex */
301 	if (!mutex_trylock(&mos_parport->serial->disc_mutex)) {
302 		dev_dbg(dev, "%s: rescheduling tasklet\n", __func__);
303 		tasklet_schedule(&mos_parport->urb_tasklet);
304 		return;
305 	}
306 
307 	/* if device disconnected, game over */
308 	if (unlikely(mos_parport->serial->disconnected)) {
309 		mutex_unlock(&mos_parport->serial->disc_mutex);
310 		return;
311 	}
312 
313 	spin_lock_irqsave(&mos_parport->listlock, flags);
314 	if (list_empty(&mos_parport->deferred_urbs)) {
315 		spin_unlock_irqrestore(&mos_parport->listlock, flags);
316 		mutex_unlock(&mos_parport->serial->disc_mutex);
317 		dev_dbg(dev, "%s: deferred_urbs list empty\n", __func__);
318 		return;
319 	}
320 
321 	/* move contents of deferred_urbs list to active_urbs list and submit */
322 	list_for_each_safe(cursor, next, &mos_parport->deferred_urbs)
323 		list_move_tail(cursor, &mos_parport->active_urbs);
324 	list_for_each_entry_safe(urbtrack, tmp, &mos_parport->active_urbs,
325 			    urblist_entry) {
326 		ret_val = usb_submit_urb(urbtrack->urb, GFP_ATOMIC);
327 		dev_dbg(dev, "%s: urb submitted\n", __func__);
328 		if (ret_val) {
329 			dev_err(dev, "usb_submit_urb() failed: %d\n", ret_val);
330 			list_del(&urbtrack->urblist_entry);
331 			kref_put(&urbtrack->ref_count, destroy_urbtracker);
332 		}
333 	}
334 	spin_unlock_irqrestore(&mos_parport->listlock, flags);
335 	mutex_unlock(&mos_parport->serial->disc_mutex);
336 }
337 
338 /* callback for parallel port control urbs submitted asynchronously */
339 static void async_complete(struct urb *urb)
340 {
341 	struct urbtracker *urbtrack = urb->context;
342 	int status = urb->status;
343 
344 	if (unlikely(status))
345 		dev_dbg(&urb->dev->dev, "%s - nonzero urb status received: %d\n", __func__, status);
346 
347 	/* remove the urbtracker from the active_urbs list */
348 	spin_lock(&urbtrack->mos_parport->listlock);
349 	list_del(&urbtrack->urblist_entry);
350 	spin_unlock(&urbtrack->mos_parport->listlock);
351 	kref_put(&urbtrack->ref_count, destroy_urbtracker);
352 }
353 
354 static int write_parport_reg_nonblock(struct mos7715_parport *mos_parport,
355 				      enum mos_regs reg, __u8 data)
356 {
357 	struct urbtracker *urbtrack;
358 	int ret_val;
359 	unsigned long flags;
360 	struct usb_serial *serial = mos_parport->serial;
361 	struct usb_device *usbdev = serial->dev;
362 
363 	/* create and initialize the control urb and containing urbtracker */
364 	urbtrack = kmalloc(sizeof(struct urbtracker), GFP_ATOMIC);
365 	if (!urbtrack)
366 		return -ENOMEM;
367 
368 	kref_get(&mos_parport->ref_count);
369 	urbtrack->mos_parport = mos_parport;
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_init(&urbtrack->ref_count);
391 	INIT_LIST_HEAD(&urbtrack->urblist_entry);
392 
393 	/*
394 	 * get the disconnect mutex, or add tracker to the deferred_urbs list
395 	 * and schedule a tasklet to try again later
396 	 */
397 	if (!mutex_trylock(&serial->disc_mutex)) {
398 		spin_lock_irqsave(&mos_parport->listlock, flags);
399 		list_add_tail(&urbtrack->urblist_entry,
400 			      &mos_parport->deferred_urbs);
401 		spin_unlock_irqrestore(&mos_parport->listlock, flags);
402 		tasklet_schedule(&mos_parport->urb_tasklet);
403 		dev_dbg(&usbdev->dev, "tasklet scheduled\n");
404 		return 0;
405 	}
406 
407 	/* bail if device disconnected */
408 	if (serial->disconnected) {
409 		kref_put(&urbtrack->ref_count, destroy_urbtracker);
410 		mutex_unlock(&serial->disc_mutex);
411 		return -ENODEV;
412 	}
413 
414 	/* add the tracker to the active_urbs list and submit */
415 	spin_lock_irqsave(&mos_parport->listlock, flags);
416 	list_add_tail(&urbtrack->urblist_entry, &mos_parport->active_urbs);
417 	spin_unlock_irqrestore(&mos_parport->listlock, flags);
418 	ret_val = usb_submit_urb(urbtrack->urb, GFP_ATOMIC);
419 	mutex_unlock(&serial->disc_mutex);
420 	if (ret_val) {
421 		dev_err(&usbdev->dev,
422 			"%s: submit_urb() failed: %d\n", __func__, ret_val);
423 		spin_lock_irqsave(&mos_parport->listlock, flags);
424 		list_del(&urbtrack->urblist_entry);
425 		spin_unlock_irqrestore(&mos_parport->listlock, flags);
426 		kref_put(&urbtrack->ref_count, destroy_urbtracker);
427 		return ret_val;
428 	}
429 	return 0;
430 }
431 
432 /*
433  * This is the the common top part of all parallel port callback operations that
434  * send synchronous messages to the device.  This implements convoluted locking
435  * that avoids two scenarios: (1) a port operation is called after usbserial
436  * has called our release function, at which point struct mos7715_parport has
437  * been destroyed, and (2) the device has been disconnected, but usbserial has
438  * not called the release function yet because someone has a serial port open.
439  * The shared release_lock prevents the first, and the mutex and disconnected
440  * flag maintained by usbserial covers the second.  We also use the msg_pending
441  * flag to ensure that all synchronous usb message calls have completed before
442  * our release function can return.
443  */
444 static int parport_prologue(struct parport *pp)
445 {
446 	struct mos7715_parport *mos_parport;
447 
448 	spin_lock(&release_lock);
449 	mos_parport = pp->private_data;
450 	if (unlikely(mos_parport == NULL)) {
451 		/* release fn called, port struct destroyed */
452 		spin_unlock(&release_lock);
453 		return -1;
454 	}
455 	mos_parport->msg_pending = true;   /* synch usb call pending */
456 	reinit_completion(&mos_parport->syncmsg_compl);
457 	spin_unlock(&release_lock);
458 
459 	mutex_lock(&mos_parport->serial->disc_mutex);
460 	if (mos_parport->serial->disconnected) {
461 		/* device disconnected */
462 		mutex_unlock(&mos_parport->serial->disc_mutex);
463 		mos_parport->msg_pending = false;
464 		complete(&mos_parport->syncmsg_compl);
465 		return -1;
466 	}
467 
468 	return 0;
469 }
470 
471 /*
472  * This is the common bottom part of all parallel port functions that send
473  * synchronous messages to the device.
474  */
475 static inline void parport_epilogue(struct parport *pp)
476 {
477 	struct mos7715_parport *mos_parport = pp->private_data;
478 	mutex_unlock(&mos_parport->serial->disc_mutex);
479 	mos_parport->msg_pending = false;
480 	complete(&mos_parport->syncmsg_compl);
481 }
482 
483 static void parport_mos7715_write_data(struct parport *pp, unsigned char d)
484 {
485 	struct mos7715_parport *mos_parport = pp->private_data;
486 
487 	if (parport_prologue(pp) < 0)
488 		return;
489 	mos7715_change_mode(mos_parport, SPP);
490 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DPR, (__u8)d);
491 	parport_epilogue(pp);
492 }
493 
494 static unsigned char parport_mos7715_read_data(struct parport *pp)
495 {
496 	struct mos7715_parport *mos_parport = pp->private_data;
497 	unsigned char d;
498 
499 	if (parport_prologue(pp) < 0)
500 		return 0;
501 	read_mos_reg(mos_parport->serial, dummy, MOS7720_DPR, &d);
502 	parport_epilogue(pp);
503 	return d;
504 }
505 
506 static void parport_mos7715_write_control(struct parport *pp, unsigned char d)
507 {
508 	struct mos7715_parport *mos_parport = pp->private_data;
509 	__u8 data;
510 
511 	if (parport_prologue(pp) < 0)
512 		return;
513 	data = ((__u8)d & 0x0f) | (mos_parport->shadowDCR & 0xf0);
514 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR, data);
515 	mos_parport->shadowDCR = data;
516 	parport_epilogue(pp);
517 }
518 
519 static unsigned char parport_mos7715_read_control(struct parport *pp)
520 {
521 	struct mos7715_parport *mos_parport = pp->private_data;
522 	__u8 dcr;
523 
524 	spin_lock(&release_lock);
525 	mos_parport = pp->private_data;
526 	if (unlikely(mos_parport == NULL)) {
527 		spin_unlock(&release_lock);
528 		return 0;
529 	}
530 	dcr = mos_parport->shadowDCR & 0x0f;
531 	spin_unlock(&release_lock);
532 	return dcr;
533 }
534 
535 static unsigned char parport_mos7715_frob_control(struct parport *pp,
536 						  unsigned char mask,
537 						  unsigned char val)
538 {
539 	struct mos7715_parport *mos_parport = pp->private_data;
540 	__u8 dcr;
541 
542 	mask &= 0x0f;
543 	val &= 0x0f;
544 	if (parport_prologue(pp) < 0)
545 		return 0;
546 	mos_parport->shadowDCR = (mos_parport->shadowDCR & (~mask)) ^ val;
547 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
548 		      mos_parport->shadowDCR);
549 	dcr = mos_parport->shadowDCR & 0x0f;
550 	parport_epilogue(pp);
551 	return dcr;
552 }
553 
554 static unsigned char parport_mos7715_read_status(struct parport *pp)
555 {
556 	unsigned char status;
557 	struct mos7715_parport *mos_parport = pp->private_data;
558 
559 	spin_lock(&release_lock);
560 	mos_parport = pp->private_data;
561 	if (unlikely(mos_parport == NULL)) {	/* release called */
562 		spin_unlock(&release_lock);
563 		return 0;
564 	}
565 	status = atomic_read(&mos_parport->shadowDSR) & 0xf8;
566 	spin_unlock(&release_lock);
567 	return status;
568 }
569 
570 static void parport_mos7715_enable_irq(struct parport *pp)
571 {
572 }
573 
574 static void parport_mos7715_disable_irq(struct parport *pp)
575 {
576 }
577 
578 static void parport_mos7715_data_forward(struct parport *pp)
579 {
580 	struct mos7715_parport *mos_parport = pp->private_data;
581 
582 	if (parport_prologue(pp) < 0)
583 		return;
584 	mos7715_change_mode(mos_parport, PS2);
585 	mos_parport->shadowDCR &=  ~0x20;
586 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
587 		      mos_parport->shadowDCR);
588 	parport_epilogue(pp);
589 }
590 
591 static void parport_mos7715_data_reverse(struct parport *pp)
592 {
593 	struct mos7715_parport *mos_parport = pp->private_data;
594 
595 	if (parport_prologue(pp) < 0)
596 		return;
597 	mos7715_change_mode(mos_parport, PS2);
598 	mos_parport->shadowDCR |= 0x20;
599 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
600 		      mos_parport->shadowDCR);
601 	parport_epilogue(pp);
602 }
603 
604 static void parport_mos7715_init_state(struct pardevice *dev,
605 				       struct parport_state *s)
606 {
607 	s->u.pc.ctr = DCR_INIT_VAL;
608 	s->u.pc.ecr = ECR_INIT_VAL;
609 }
610 
611 /* N.B. Parport core code requires that this function not block */
612 static void parport_mos7715_save_state(struct parport *pp,
613 				       struct parport_state *s)
614 {
615 	struct mos7715_parport *mos_parport;
616 
617 	spin_lock(&release_lock);
618 	mos_parport = pp->private_data;
619 	if (unlikely(mos_parport == NULL)) {	/* release called */
620 		spin_unlock(&release_lock);
621 		return;
622 	}
623 	s->u.pc.ctr = mos_parport->shadowDCR;
624 	s->u.pc.ecr = mos_parport->shadowECR;
625 	spin_unlock(&release_lock);
626 }
627 
628 /* N.B. Parport core code requires that this function not block */
629 static void parport_mos7715_restore_state(struct parport *pp,
630 					  struct parport_state *s)
631 {
632 	struct mos7715_parport *mos_parport;
633 
634 	spin_lock(&release_lock);
635 	mos_parport = pp->private_data;
636 	if (unlikely(mos_parport == NULL)) {	/* release called */
637 		spin_unlock(&release_lock);
638 		return;
639 	}
640 	write_parport_reg_nonblock(mos_parport, MOS7720_DCR,
641 				   mos_parport->shadowDCR);
642 	write_parport_reg_nonblock(mos_parport, MOS7720_ECR,
643 				   mos_parport->shadowECR);
644 	spin_unlock(&release_lock);
645 }
646 
647 static size_t parport_mos7715_write_compat(struct parport *pp,
648 					   const void *buffer,
649 					   size_t len, int flags)
650 {
651 	int retval;
652 	struct mos7715_parport *mos_parport = pp->private_data;
653 	int actual_len;
654 
655 	if (parport_prologue(pp) < 0)
656 		return 0;
657 	mos7715_change_mode(mos_parport, PPF);
658 	retval = usb_bulk_msg(mos_parport->serial->dev,
659 			      usb_sndbulkpipe(mos_parport->serial->dev, 2),
660 			      (void *)buffer, len, &actual_len,
661 			      MOS_WDR_TIMEOUT);
662 	parport_epilogue(pp);
663 	if (retval) {
664 		dev_err(&mos_parport->serial->dev->dev,
665 			"mos7720: usb_bulk_msg() failed: %d\n", retval);
666 		return 0;
667 	}
668 	return actual_len;
669 }
670 
671 static struct parport_operations parport_mos7715_ops = {
672 	.owner =		THIS_MODULE,
673 	.write_data =		parport_mos7715_write_data,
674 	.read_data =		parport_mos7715_read_data,
675 
676 	.write_control =	parport_mos7715_write_control,
677 	.read_control =		parport_mos7715_read_control,
678 	.frob_control =		parport_mos7715_frob_control,
679 
680 	.read_status =		parport_mos7715_read_status,
681 
682 	.enable_irq =		parport_mos7715_enable_irq,
683 	.disable_irq =		parport_mos7715_disable_irq,
684 
685 	.data_forward =		parport_mos7715_data_forward,
686 	.data_reverse =		parport_mos7715_data_reverse,
687 
688 	.init_state =		parport_mos7715_init_state,
689 	.save_state =		parport_mos7715_save_state,
690 	.restore_state =	parport_mos7715_restore_state,
691 
692 	.compat_write_data =	parport_mos7715_write_compat,
693 
694 	.nibble_read_data =	parport_ieee1284_read_nibble,
695 	.byte_read_data =	parport_ieee1284_read_byte,
696 };
697 
698 /*
699  * Allocate and initialize parallel port control struct, initialize
700  * the parallel port hardware device, and register with the parport subsystem.
701  */
702 static int mos7715_parport_init(struct usb_serial *serial)
703 {
704 	struct mos7715_parport *mos_parport;
705 
706 	/* allocate and initialize parallel port control struct */
707 	mos_parport = kzalloc(sizeof(struct mos7715_parport), GFP_KERNEL);
708 	if (!mos_parport)
709 		return -ENOMEM;
710 
711 	mos_parport->msg_pending = false;
712 	kref_init(&mos_parport->ref_count);
713 	spin_lock_init(&mos_parport->listlock);
714 	INIT_LIST_HEAD(&mos_parport->active_urbs);
715 	INIT_LIST_HEAD(&mos_parport->deferred_urbs);
716 	usb_set_serial_data(serial, mos_parport); /* hijack private pointer */
717 	mos_parport->serial = serial;
718 	tasklet_init(&mos_parport->urb_tasklet, send_deferred_urbs,
719 		     (unsigned long) mos_parport);
720 	init_completion(&mos_parport->syncmsg_compl);
721 
722 	/* cycle parallel port reset bit */
723 	write_mos_reg(mos_parport->serial, dummy, MOS7720_PP_REG, (__u8)0x80);
724 	write_mos_reg(mos_parport->serial, dummy, MOS7720_PP_REG, (__u8)0x00);
725 
726 	/* initialize device registers */
727 	mos_parport->shadowDCR = DCR_INIT_VAL;
728 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
729 		      mos_parport->shadowDCR);
730 	mos_parport->shadowECR = ECR_INIT_VAL;
731 	write_mos_reg(mos_parport->serial, dummy, MOS7720_ECR,
732 		      mos_parport->shadowECR);
733 
734 	/* register with parport core */
735 	mos_parport->pp = parport_register_port(0, PARPORT_IRQ_NONE,
736 						PARPORT_DMA_NONE,
737 						&parport_mos7715_ops);
738 	if (mos_parport->pp == NULL) {
739 		dev_err(&serial->interface->dev,
740 			"Could not register parport\n");
741 		kref_put(&mos_parport->ref_count, destroy_mos_parport);
742 		return -EIO;
743 	}
744 	mos_parport->pp->private_data = mos_parport;
745 	mos_parport->pp->modes = PARPORT_MODE_COMPAT | PARPORT_MODE_PCSPP;
746 	mos_parport->pp->dev = &serial->interface->dev;
747 	parport_announce_port(mos_parport->pp);
748 
749 	return 0;
750 }
751 #endif	/* CONFIG_USB_SERIAL_MOS7715_PARPORT */
752 
753 /*
754  * mos7720_interrupt_callback
755  *	this is the callback function for when we have received data on the
756  *	interrupt endpoint.
757  */
758 static void mos7720_interrupt_callback(struct urb *urb)
759 {
760 	int result;
761 	int length;
762 	int status = urb->status;
763 	struct device *dev = &urb->dev->dev;
764 	__u8 *data;
765 	__u8 sp1;
766 	__u8 sp2;
767 
768 	switch (status) {
769 	case 0:
770 		/* success */
771 		break;
772 	case -ECONNRESET:
773 	case -ENOENT:
774 	case -ESHUTDOWN:
775 		/* this urb is terminated, clean up */
776 		dev_dbg(dev, "%s - urb shutting down with status: %d\n", __func__, status);
777 		return;
778 	default:
779 		dev_dbg(dev, "%s - nonzero urb status received: %d\n", __func__, status);
780 		goto exit;
781 	}
782 
783 	length = urb->actual_length;
784 	data = urb->transfer_buffer;
785 
786 	/* Moschip get 4 bytes
787 	 * Byte 1 IIR Port 1 (port.number is 0)
788 	 * Byte 2 IIR Port 2 (port.number is 1)
789 	 * Byte 3 --------------
790 	 * Byte 4 FIFO status for both */
791 
792 	/* the above description is inverted
793 	 * 	oneukum 2007-03-14 */
794 
795 	if (unlikely(length != 4)) {
796 		dev_dbg(dev, "Wrong data !!!\n");
797 		return;
798 	}
799 
800 	sp1 = data[3];
801 	sp2 = data[2];
802 
803 	if ((sp1 | sp2) & 0x01) {
804 		/* No Interrupt Pending in both the ports */
805 		dev_dbg(dev, "No Interrupt !!!\n");
806 	} else {
807 		switch (sp1 & 0x0f) {
808 		case SERIAL_IIR_RLS:
809 			dev_dbg(dev, "Serial Port 1: Receiver status error or address bit detected in 9-bit mode\n");
810 			break;
811 		case SERIAL_IIR_CTI:
812 			dev_dbg(dev, "Serial Port 1: Receiver time out\n");
813 			break;
814 		case SERIAL_IIR_MS:
815 			/* dev_dbg(dev, "Serial Port 1: Modem status change\n"); */
816 			break;
817 		}
818 
819 		switch (sp2 & 0x0f) {
820 		case SERIAL_IIR_RLS:
821 			dev_dbg(dev, "Serial Port 2: Receiver status error or address bit detected in 9-bit mode\n");
822 			break;
823 		case SERIAL_IIR_CTI:
824 			dev_dbg(dev, "Serial Port 2: Receiver time out\n");
825 			break;
826 		case SERIAL_IIR_MS:
827 			/* dev_dbg(dev, "Serial Port 2: Modem status change\n"); */
828 			break;
829 		}
830 	}
831 
832 exit:
833 	result = usb_submit_urb(urb, GFP_ATOMIC);
834 	if (result)
835 		dev_err(dev, "%s - Error %d submitting control urb\n", __func__, result);
836 }
837 
838 /*
839  * mos7715_interrupt_callback
840  *	this is the 7715's callback function for when we have received data on
841  *	the interrupt endpoint.
842  */
843 static void mos7715_interrupt_callback(struct urb *urb)
844 {
845 	int result;
846 	int length;
847 	int status = urb->status;
848 	struct device *dev = &urb->dev->dev;
849 	__u8 *data;
850 	__u8 iir;
851 
852 	switch (status) {
853 	case 0:
854 		/* success */
855 		break;
856 	case -ECONNRESET:
857 	case -ENOENT:
858 	case -ESHUTDOWN:
859 	case -ENODEV:
860 		/* this urb is terminated, clean up */
861 		dev_dbg(dev, "%s - urb shutting down with status: %d\n", __func__, status);
862 		return;
863 	default:
864 		dev_dbg(dev, "%s - nonzero urb status received: %d\n", __func__, status);
865 		goto exit;
866 	}
867 
868 	length = urb->actual_length;
869 	data = urb->transfer_buffer;
870 
871 	/* Structure of data from 7715 device:
872 	 * Byte 1: IIR serial Port
873 	 * Byte 2: unused
874 	 * Byte 2: DSR parallel port
875 	 * Byte 4: FIFO status for both */
876 
877 	if (unlikely(length != 4)) {
878 		dev_dbg(dev, "Wrong data !!!\n");
879 		return;
880 	}
881 
882 	iir = data[0];
883 	if (!(iir & 0x01)) {	/* serial port interrupt pending */
884 		switch (iir & 0x0f) {
885 		case SERIAL_IIR_RLS:
886 			dev_dbg(dev, "Serial Port: Receiver status error or address bit detected in 9-bit mode\n");
887 			break;
888 		case SERIAL_IIR_CTI:
889 			dev_dbg(dev, "Serial Port: Receiver time out\n");
890 			break;
891 		case SERIAL_IIR_MS:
892 			/* dev_dbg(dev, "Serial Port: Modem status change\n"); */
893 			break;
894 		}
895 	}
896 
897 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
898 	{       /* update local copy of DSR reg */
899 		struct usb_serial_port *port = urb->context;
900 		struct mos7715_parport *mos_parport = port->serial->private;
901 		if (unlikely(mos_parport == NULL))
902 			return;
903 		atomic_set(&mos_parport->shadowDSR, data[2]);
904 	}
905 #endif
906 
907 exit:
908 	result = usb_submit_urb(urb, GFP_ATOMIC);
909 	if (result)
910 		dev_err(dev, "%s - Error %d submitting control urb\n", __func__, result);
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 	int status = urb->status;
924 
925 	if (status) {
926 		dev_dbg(&urb->dev->dev, "nonzero read bulk status received: %d\n", status);
927 		return;
928 	}
929 
930 	port = urb->context;
931 
932 	dev_dbg(&port->dev, "Entering...%s\n", __func__);
933 
934 	data = urb->transfer_buffer;
935 
936 	if (urb->actual_length) {
937 		tty_insert_flip_string(&port->port, data, urb->actual_length);
938 		tty_flip_buffer_push(&port->port);
939 	}
940 
941 	if (port->read_urb->status != -EINPROGRESS) {
942 		retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
943 		if (retval)
944 			dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, retval = %d\n", retval);
945 	}
946 }
947 
948 /*
949  * mos7720_bulk_out_data_callback
950  *	this is the callback function for when we have finished sending serial
951  *	data on the bulk out endpoint.
952  */
953 static void mos7720_bulk_out_data_callback(struct urb *urb)
954 {
955 	struct moschip_port *mos7720_port;
956 	int status = urb->status;
957 
958 	if (status) {
959 		dev_dbg(&urb->dev->dev, "nonzero write bulk status received:%d\n", status);
960 		return;
961 	}
962 
963 	mos7720_port = urb->context;
964 	if (!mos7720_port) {
965 		dev_dbg(&urb->dev->dev, "NULL mos7720_port pointer\n");
966 		return ;
967 	}
968 
969 	if (mos7720_port->open)
970 		tty_port_tty_wakeup(&mos7720_port->port->port);
971 }
972 
973 /*
974  * mos77xx_probe
975  *	this function installs the appropriate read interrupt endpoint callback
976  *	depending on whether the device is a 7720 or 7715, thus avoiding costly
977  *	run-time checks in the high-frequency callback routine itself.
978  */
979 static int mos77xx_probe(struct usb_serial *serial,
980 			 const struct usb_device_id *id)
981 {
982 	if (id->idProduct == MOSCHIP_DEVICE_ID_7715)
983 		moschip7720_2port_driver.read_int_callback =
984 			mos7715_interrupt_callback;
985 	else
986 		moschip7720_2port_driver.read_int_callback =
987 			mos7720_interrupt_callback;
988 
989 	return 0;
990 }
991 
992 static int mos77xx_calc_num_ports(struct usb_serial *serial)
993 {
994 	u16 product = le16_to_cpu(serial->dev->descriptor.idProduct);
995 	if (product == MOSCHIP_DEVICE_ID_7715)
996 		return 1;
997 
998 	return 2;
999 }
1000 
1001 static int mos7720_open(struct tty_struct *tty, struct usb_serial_port *port)
1002 {
1003 	struct usb_serial *serial;
1004 	struct urb *urb;
1005 	struct moschip_port *mos7720_port;
1006 	int response;
1007 	int port_number;
1008 	__u8 data;
1009 	int allocated_urbs = 0;
1010 	int j;
1011 
1012 	serial = port->serial;
1013 
1014 	mos7720_port = usb_get_serial_port_data(port);
1015 	if (mos7720_port == NULL)
1016 		return -ENODEV;
1017 
1018 	usb_clear_halt(serial->dev, port->write_urb->pipe);
1019 	usb_clear_halt(serial->dev, port->read_urb->pipe);
1020 
1021 	/* Initialising the write urb pool */
1022 	for (j = 0; j < NUM_URBS; ++j) {
1023 		urb = usb_alloc_urb(0, GFP_KERNEL);
1024 		mos7720_port->write_urb_pool[j] = urb;
1025 		if (!urb)
1026 			continue;
1027 
1028 		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
1029 					       GFP_KERNEL);
1030 		if (!urb->transfer_buffer) {
1031 			usb_free_urb(mos7720_port->write_urb_pool[j]);
1032 			mos7720_port->write_urb_pool[j] = NULL;
1033 			continue;
1034 		}
1035 		allocated_urbs++;
1036 	}
1037 
1038 	if (!allocated_urbs)
1039 		return -ENOMEM;
1040 
1041 	 /* Initialize MCS7720 -- Write Init values to corresponding Registers
1042 	  *
1043 	  * Register Index
1044 	  * 0 : MOS7720_THR/MOS7720_RHR
1045 	  * 1 : MOS7720_IER
1046 	  * 2 : MOS7720_FCR
1047 	  * 3 : MOS7720_LCR
1048 	  * 4 : MOS7720_MCR
1049 	  * 5 : MOS7720_LSR
1050 	  * 6 : MOS7720_MSR
1051 	  * 7 : MOS7720_SPR
1052 	  *
1053 	  * 0x08 : SP1/2 Control Reg
1054 	  */
1055 	port_number = port->port_number;
1056 	read_mos_reg(serial, port_number, MOS7720_LSR, &data);
1057 
1058 	dev_dbg(&port->dev, "SS::%p LSR:%x\n", mos7720_port, data);
1059 
1060 	write_mos_reg(serial, dummy, MOS7720_SP1_REG, 0x02);
1061 	write_mos_reg(serial, dummy, MOS7720_SP2_REG, 0x02);
1062 
1063 	write_mos_reg(serial, port_number, MOS7720_IER, 0x00);
1064 	write_mos_reg(serial, port_number, MOS7720_FCR, 0x00);
1065 
1066 	write_mos_reg(serial, port_number, MOS7720_FCR, 0xcf);
1067 	mos7720_port->shadowLCR = 0x03;
1068 	write_mos_reg(serial, port_number, MOS7720_LCR,
1069 		      mos7720_port->shadowLCR);
1070 	mos7720_port->shadowMCR = 0x0b;
1071 	write_mos_reg(serial, port_number, MOS7720_MCR,
1072 		      mos7720_port->shadowMCR);
1073 
1074 	write_mos_reg(serial, port_number, MOS7720_SP_CONTROL_REG, 0x00);
1075 	read_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG, &data);
1076 	data = data | (port->port_number + 1);
1077 	write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG, data);
1078 	mos7720_port->shadowLCR = 0x83;
1079 	write_mos_reg(serial, port_number, MOS7720_LCR,
1080 		      mos7720_port->shadowLCR);
1081 	write_mos_reg(serial, port_number, MOS7720_THR, 0x0c);
1082 	write_mos_reg(serial, port_number, MOS7720_IER, 0x00);
1083 	mos7720_port->shadowLCR = 0x03;
1084 	write_mos_reg(serial, port_number, MOS7720_LCR,
1085 		      mos7720_port->shadowLCR);
1086 	write_mos_reg(serial, port_number, MOS7720_IER, 0x0c);
1087 
1088 	response = usb_submit_urb(port->read_urb, GFP_KERNEL);
1089 	if (response)
1090 		dev_err(&port->dev, "%s - Error %d submitting read urb\n",
1091 							__func__, response);
1092 
1093 	/* initialize our port settings */
1094 	mos7720_port->shadowMCR = UART_MCR_OUT2; /* Must set to enable ints! */
1095 
1096 	/* send a open port command */
1097 	mos7720_port->open = 1;
1098 
1099 	return 0;
1100 }
1101 
1102 /*
1103  * mos7720_chars_in_buffer
1104  *	this function is called by the tty driver when it wants to know how many
1105  *	bytes of data we currently have outstanding in the port (data that has
1106  *	been written, but hasn't made it out the port yet)
1107  *	If successful, we return the number of bytes left to be written in the
1108  *	system,
1109  *	Otherwise we return a negative error number.
1110  */
1111 static int mos7720_chars_in_buffer(struct tty_struct *tty)
1112 {
1113 	struct usb_serial_port *port = tty->driver_data;
1114 	int i;
1115 	int chars = 0;
1116 	struct moschip_port *mos7720_port;
1117 
1118 	mos7720_port = usb_get_serial_port_data(port);
1119 	if (mos7720_port == NULL)
1120 		return 0;
1121 
1122 	for (i = 0; i < NUM_URBS; ++i) {
1123 		if (mos7720_port->write_urb_pool[i] &&
1124 		    mos7720_port->write_urb_pool[i]->status == -EINPROGRESS)
1125 			chars += URB_TRANSFER_BUFFER_SIZE;
1126 	}
1127 	dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars);
1128 	return chars;
1129 }
1130 
1131 static void mos7720_close(struct usb_serial_port *port)
1132 {
1133 	struct usb_serial *serial;
1134 	struct moschip_port *mos7720_port;
1135 	int j;
1136 
1137 	serial = port->serial;
1138 
1139 	mos7720_port = usb_get_serial_port_data(port);
1140 	if (mos7720_port == NULL)
1141 		return;
1142 
1143 	for (j = 0; j < NUM_URBS; ++j)
1144 		usb_kill_urb(mos7720_port->write_urb_pool[j]);
1145 
1146 	/* Freeing Write URBs */
1147 	for (j = 0; j < NUM_URBS; ++j) {
1148 		if (mos7720_port->write_urb_pool[j]) {
1149 			kfree(mos7720_port->write_urb_pool[j]->transfer_buffer);
1150 			usb_free_urb(mos7720_port->write_urb_pool[j]);
1151 		}
1152 	}
1153 
1154 	/* While closing port, shutdown all bulk read, write  *
1155 	 * and interrupt read if they exists, otherwise nop   */
1156 	usb_kill_urb(port->write_urb);
1157 	usb_kill_urb(port->read_urb);
1158 
1159 	write_mos_reg(serial, port->port_number, MOS7720_MCR, 0x00);
1160 	write_mos_reg(serial, port->port_number, MOS7720_IER, 0x00);
1161 
1162 	mos7720_port->open = 0;
1163 }
1164 
1165 static void mos7720_break(struct tty_struct *tty, int break_state)
1166 {
1167 	struct usb_serial_port *port = tty->driver_data;
1168 	unsigned char data;
1169 	struct usb_serial *serial;
1170 	struct moschip_port *mos7720_port;
1171 
1172 	serial = port->serial;
1173 
1174 	mos7720_port = usb_get_serial_port_data(port);
1175 	if (mos7720_port == NULL)
1176 		return;
1177 
1178 	if (break_state == -1)
1179 		data = mos7720_port->shadowLCR | UART_LCR_SBC;
1180 	else
1181 		data = mos7720_port->shadowLCR & ~UART_LCR_SBC;
1182 
1183 	mos7720_port->shadowLCR  = data;
1184 	write_mos_reg(serial, port->port_number, MOS7720_LCR,
1185 		      mos7720_port->shadowLCR);
1186 }
1187 
1188 /*
1189  * mos7720_write_room
1190  *	this function is called by the tty driver when it wants to know how many
1191  *	bytes of data we can accept for a specific port.
1192  *	If successful, we return the amount of room that we have for this port
1193  *	Otherwise we return a negative error number.
1194  */
1195 static int mos7720_write_room(struct tty_struct *tty)
1196 {
1197 	struct usb_serial_port *port = tty->driver_data;
1198 	struct moschip_port *mos7720_port;
1199 	int room = 0;
1200 	int i;
1201 
1202 	mos7720_port = usb_get_serial_port_data(port);
1203 	if (mos7720_port == NULL)
1204 		return -ENODEV;
1205 
1206 	/* FIXME: Locking */
1207 	for (i = 0; i < NUM_URBS; ++i) {
1208 		if (mos7720_port->write_urb_pool[i] &&
1209 		    mos7720_port->write_urb_pool[i]->status != -EINPROGRESS)
1210 			room += URB_TRANSFER_BUFFER_SIZE;
1211 	}
1212 
1213 	dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
1214 	return room;
1215 }
1216 
1217 static int mos7720_write(struct tty_struct *tty, struct usb_serial_port *port,
1218 				 const unsigned char *data, int count)
1219 {
1220 	int status;
1221 	int i;
1222 	int bytes_sent = 0;
1223 	int transfer_size;
1224 
1225 	struct moschip_port *mos7720_port;
1226 	struct usb_serial *serial;
1227 	struct urb    *urb;
1228 	const unsigned char *current_position = data;
1229 
1230 	serial = port->serial;
1231 
1232 	mos7720_port = usb_get_serial_port_data(port);
1233 	if (mos7720_port == NULL)
1234 		return -ENODEV;
1235 
1236 	/* try to find a free urb in the list */
1237 	urb = NULL;
1238 
1239 	for (i = 0; i < NUM_URBS; ++i) {
1240 		if (mos7720_port->write_urb_pool[i] &&
1241 		    mos7720_port->write_urb_pool[i]->status != -EINPROGRESS) {
1242 			urb = mos7720_port->write_urb_pool[i];
1243 			dev_dbg(&port->dev, "URB:%d\n", i);
1244 			break;
1245 		}
1246 	}
1247 
1248 	if (urb == NULL) {
1249 		dev_dbg(&port->dev, "%s - no more free urbs\n", __func__);
1250 		goto exit;
1251 	}
1252 
1253 	if (urb->transfer_buffer == NULL) {
1254 		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
1255 					       GFP_KERNEL);
1256 		if (!urb->transfer_buffer)
1257 			goto exit;
1258 	}
1259 	transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
1260 
1261 	memcpy(urb->transfer_buffer, current_position, transfer_size);
1262 	usb_serial_debug_data(&port->dev, __func__, transfer_size,
1263 			      urb->transfer_buffer);
1264 
1265 	/* fill urb with data and submit  */
1266 	usb_fill_bulk_urb(urb, serial->dev,
1267 			  usb_sndbulkpipe(serial->dev,
1268 					port->bulk_out_endpointAddress),
1269 			  urb->transfer_buffer, transfer_size,
1270 			  mos7720_bulk_out_data_callback, mos7720_port);
1271 
1272 	/* send it down the pipe */
1273 	status = usb_submit_urb(urb, GFP_ATOMIC);
1274 	if (status) {
1275 		dev_err_console(port, "%s - usb_submit_urb(write bulk) failed "
1276 			"with status = %d\n", __func__, status);
1277 		bytes_sent = status;
1278 		goto exit;
1279 	}
1280 	bytes_sent = transfer_size;
1281 
1282 exit:
1283 	return bytes_sent;
1284 }
1285 
1286 static void mos7720_throttle(struct tty_struct *tty)
1287 {
1288 	struct usb_serial_port *port = tty->driver_data;
1289 	struct moschip_port *mos7720_port;
1290 	int status;
1291 
1292 	mos7720_port = usb_get_serial_port_data(port);
1293 
1294 	if (mos7720_port == NULL)
1295 		return;
1296 
1297 	if (!mos7720_port->open) {
1298 		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
1299 		return;
1300 	}
1301 
1302 	/* if we are implementing XON/XOFF, send the stop character */
1303 	if (I_IXOFF(tty)) {
1304 		unsigned char stop_char = STOP_CHAR(tty);
1305 		status = mos7720_write(tty, port, &stop_char, 1);
1306 		if (status <= 0)
1307 			return;
1308 	}
1309 
1310 	/* if we are implementing RTS/CTS, toggle that line */
1311 	if (tty->termios.c_cflag & CRTSCTS) {
1312 		mos7720_port->shadowMCR &= ~UART_MCR_RTS;
1313 		write_mos_reg(port->serial, port->port_number, MOS7720_MCR,
1314 			      mos7720_port->shadowMCR);
1315 	}
1316 }
1317 
1318 static void mos7720_unthrottle(struct tty_struct *tty)
1319 {
1320 	struct usb_serial_port *port = tty->driver_data;
1321 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
1322 	int status;
1323 
1324 	if (mos7720_port == NULL)
1325 		return;
1326 
1327 	if (!mos7720_port->open) {
1328 		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
1329 		return;
1330 	}
1331 
1332 	/* if we are implementing XON/XOFF, send the start character */
1333 	if (I_IXOFF(tty)) {
1334 		unsigned char start_char = START_CHAR(tty);
1335 		status = mos7720_write(tty, port, &start_char, 1);
1336 		if (status <= 0)
1337 			return;
1338 	}
1339 
1340 	/* if we are implementing RTS/CTS, toggle that line */
1341 	if (tty->termios.c_cflag & CRTSCTS) {
1342 		mos7720_port->shadowMCR |= UART_MCR_RTS;
1343 		write_mos_reg(port->serial, port->port_number, MOS7720_MCR,
1344 			      mos7720_port->shadowMCR);
1345 	}
1346 }
1347 
1348 /* FIXME: this function does not work */
1349 static int set_higher_rates(struct moschip_port *mos7720_port,
1350 			    unsigned int baud)
1351 {
1352 	struct usb_serial_port *port;
1353 	struct usb_serial *serial;
1354 	int port_number;
1355 	enum mos_regs sp_reg;
1356 	if (mos7720_port == NULL)
1357 		return -EINVAL;
1358 
1359 	port = mos7720_port->port;
1360 	serial = port->serial;
1361 
1362 	 /***********************************************
1363 	 *      Init Sequence for higher rates
1364 	 ***********************************************/
1365 	dev_dbg(&port->dev, "Sending Setting Commands ..........\n");
1366 	port_number = port->port_number;
1367 
1368 	write_mos_reg(serial, port_number, MOS7720_IER, 0x00);
1369 	write_mos_reg(serial, port_number, MOS7720_FCR, 0x00);
1370 	write_mos_reg(serial, port_number, MOS7720_FCR, 0xcf);
1371 	mos7720_port->shadowMCR = 0x0b;
1372 	write_mos_reg(serial, port_number, MOS7720_MCR,
1373 		      mos7720_port->shadowMCR);
1374 	write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG, 0x00);
1375 
1376 	/***********************************************
1377 	 *              Set for higher rates           *
1378 	 ***********************************************/
1379 	/* writing baud rate verbatum into uart clock field clearly not right */
1380 	if (port_number == 0)
1381 		sp_reg = MOS7720_SP1_REG;
1382 	else
1383 		sp_reg = MOS7720_SP2_REG;
1384 	write_mos_reg(serial, dummy, sp_reg, baud * 0x10);
1385 	write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG, 0x03);
1386 	mos7720_port->shadowMCR = 0x2b;
1387 	write_mos_reg(serial, port_number, MOS7720_MCR,
1388 		      mos7720_port->shadowMCR);
1389 
1390 	/***********************************************
1391 	 *              Set DLL/DLM
1392 	 ***********************************************/
1393 	mos7720_port->shadowLCR = mos7720_port->shadowLCR | UART_LCR_DLAB;
1394 	write_mos_reg(serial, port_number, MOS7720_LCR,
1395 		      mos7720_port->shadowLCR);
1396 	write_mos_reg(serial, port_number, MOS7720_DLL, 0x01);
1397 	write_mos_reg(serial, port_number, MOS7720_DLM, 0x00);
1398 	mos7720_port->shadowLCR = mos7720_port->shadowLCR & ~UART_LCR_DLAB;
1399 	write_mos_reg(serial, port_number, MOS7720_LCR,
1400 		      mos7720_port->shadowLCR);
1401 
1402 	return 0;
1403 }
1404 
1405 /* baud rate information */
1406 struct divisor_table_entry {
1407 	__u32  baudrate;
1408 	__u16  divisor;
1409 };
1410 
1411 /* Define table of divisors for moschip 7720 hardware	   *
1412  * These assume a 3.6864MHz crystal, the standard /16, and *
1413  * MCR.7 = 0.						   */
1414 static struct divisor_table_entry divisor_table[] = {
1415 	{   50,		2304},
1416 	{   110,	1047},	/* 2094.545455 => 230450   => .0217 % over */
1417 	{   134,	857},	/* 1713.011152 => 230398.5 => .00065% under */
1418 	{   150,	768},
1419 	{   300,	384},
1420 	{   600,	192},
1421 	{   1200,	96},
1422 	{   1800,	64},
1423 	{   2400,	48},
1424 	{   4800,	24},
1425 	{   7200,	16},
1426 	{   9600,	12},
1427 	{   19200,	6},
1428 	{   38400,	3},
1429 	{   57600,	2},
1430 	{   115200,	1},
1431 };
1432 
1433 /*****************************************************************************
1434  * calc_baud_rate_divisor
1435  *	this function calculates the proper baud rate divisor for the specified
1436  *	baud rate.
1437  *****************************************************************************/
1438 static int calc_baud_rate_divisor(struct usb_serial_port *port, int baudrate, int *divisor)
1439 {
1440 	int i;
1441 	__u16 custom;
1442 	__u16 round1;
1443 	__u16 round;
1444 
1445 
1446 	dev_dbg(&port->dev, "%s - %d\n", __func__, baudrate);
1447 
1448 	for (i = 0; i < ARRAY_SIZE(divisor_table); i++) {
1449 		if (divisor_table[i].baudrate == baudrate) {
1450 			*divisor = divisor_table[i].divisor;
1451 			return 0;
1452 		}
1453 	}
1454 
1455 	/* After trying for all the standard baud rates    *
1456 	 * Try calculating the divisor for this baud rate  */
1457 	if (baudrate > 75 &&  baudrate < 230400) {
1458 		/* get the divisor */
1459 		custom = (__u16)(230400L  / baudrate);
1460 
1461 		/* Check for round off */
1462 		round1 = (__u16)(2304000L / baudrate);
1463 		round = (__u16)(round1 - (custom * 10));
1464 		if (round > 4)
1465 			custom++;
1466 		*divisor = custom;
1467 
1468 		dev_dbg(&port->dev, "Baud %d = %d\n", baudrate, custom);
1469 		return 0;
1470 	}
1471 
1472 	dev_dbg(&port->dev, "Baud calculation Failed...\n");
1473 	return -EINVAL;
1474 }
1475 
1476 /*
1477  * send_cmd_write_baud_rate
1478  *	this function sends the proper command to change the baud rate of the
1479  *	specified port.
1480  */
1481 static int send_cmd_write_baud_rate(struct moschip_port *mos7720_port,
1482 				    int baudrate)
1483 {
1484 	struct usb_serial_port *port;
1485 	struct usb_serial *serial;
1486 	int divisor;
1487 	int status;
1488 	unsigned char number;
1489 
1490 	if (mos7720_port == NULL)
1491 		return -1;
1492 
1493 	port = mos7720_port->port;
1494 	serial = port->serial;
1495 
1496 	number = port->port_number;
1497 	dev_dbg(&port->dev, "%s - baud = %d\n", __func__, baudrate);
1498 
1499 	/* Calculate the Divisor */
1500 	status = calc_baud_rate_divisor(port, baudrate, &divisor);
1501 	if (status) {
1502 		dev_err(&port->dev, "%s - bad baud rate\n", __func__);
1503 		return status;
1504 	}
1505 
1506 	/* Enable access to divisor latch */
1507 	mos7720_port->shadowLCR = mos7720_port->shadowLCR | UART_LCR_DLAB;
1508 	write_mos_reg(serial, number, MOS7720_LCR, mos7720_port->shadowLCR);
1509 
1510 	/* Write the divisor */
1511 	write_mos_reg(serial, number, MOS7720_DLL, (__u8)(divisor & 0xff));
1512 	write_mos_reg(serial, number, MOS7720_DLM,
1513 		      (__u8)((divisor & 0xff00) >> 8));
1514 
1515 	/* Disable access to divisor latch */
1516 	mos7720_port->shadowLCR = mos7720_port->shadowLCR & ~UART_LCR_DLAB;
1517 	write_mos_reg(serial, number, MOS7720_LCR, mos7720_port->shadowLCR);
1518 
1519 	return status;
1520 }
1521 
1522 /*
1523  * change_port_settings
1524  *	This routine is called to set the UART on the device to match
1525  *      the specified new settings.
1526  */
1527 static void change_port_settings(struct tty_struct *tty,
1528 				 struct moschip_port *mos7720_port,
1529 				 struct ktermios *old_termios)
1530 {
1531 	struct usb_serial_port *port;
1532 	struct usb_serial *serial;
1533 	int baud;
1534 	unsigned cflag;
1535 	unsigned iflag;
1536 	__u8 mask = 0xff;
1537 	__u8 lData;
1538 	__u8 lParity;
1539 	__u8 lStop;
1540 	int status;
1541 	int port_number;
1542 
1543 	if (mos7720_port == NULL)
1544 		return ;
1545 
1546 	port = mos7720_port->port;
1547 	serial = port->serial;
1548 	port_number = port->port_number;
1549 
1550 	if (!mos7720_port->open) {
1551 		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
1552 		return;
1553 	}
1554 
1555 	lData = UART_LCR_WLEN8;
1556 	lStop = 0x00;	/* 1 stop bit */
1557 	lParity = 0x00;	/* No parity */
1558 
1559 	cflag = tty->termios.c_cflag;
1560 	iflag = tty->termios.c_iflag;
1561 
1562 	/* Change the number of bits */
1563 	switch (cflag & CSIZE) {
1564 	case CS5:
1565 		lData = UART_LCR_WLEN5;
1566 		mask = 0x1f;
1567 		break;
1568 
1569 	case CS6:
1570 		lData = UART_LCR_WLEN6;
1571 		mask = 0x3f;
1572 		break;
1573 
1574 	case CS7:
1575 		lData = UART_LCR_WLEN7;
1576 		mask = 0x7f;
1577 		break;
1578 	default:
1579 	case CS8:
1580 		lData = UART_LCR_WLEN8;
1581 		break;
1582 	}
1583 
1584 	/* Change the Parity bit */
1585 	if (cflag & PARENB) {
1586 		if (cflag & PARODD) {
1587 			lParity = UART_LCR_PARITY;
1588 			dev_dbg(&port->dev, "%s - parity = odd\n", __func__);
1589 		} else {
1590 			lParity = (UART_LCR_EPAR | UART_LCR_PARITY);
1591 			dev_dbg(&port->dev, "%s - parity = even\n", __func__);
1592 		}
1593 
1594 	} else {
1595 		dev_dbg(&port->dev, "%s - parity = none\n", __func__);
1596 	}
1597 
1598 	if (cflag & CMSPAR)
1599 		lParity = lParity | 0x20;
1600 
1601 	/* Change the Stop bit */
1602 	if (cflag & CSTOPB) {
1603 		lStop = UART_LCR_STOP;
1604 		dev_dbg(&port->dev, "%s - stop bits = 2\n", __func__);
1605 	} else {
1606 		lStop = 0x00;
1607 		dev_dbg(&port->dev, "%s - stop bits = 1\n", __func__);
1608 	}
1609 
1610 #define LCR_BITS_MASK		0x03	/* Mask for bits/char field */
1611 #define LCR_STOP_MASK		0x04	/* Mask for stop bits field */
1612 #define LCR_PAR_MASK		0x38	/* Mask for parity field */
1613 
1614 	/* Update the LCR with the correct value */
1615 	mos7720_port->shadowLCR &=
1616 		~(LCR_BITS_MASK | LCR_STOP_MASK | LCR_PAR_MASK);
1617 	mos7720_port->shadowLCR |= (lData | lParity | lStop);
1618 
1619 
1620 	/* Disable Interrupts */
1621 	write_mos_reg(serial, port_number, MOS7720_IER, 0x00);
1622 	write_mos_reg(serial, port_number, MOS7720_FCR, 0x00);
1623 	write_mos_reg(serial, port_number, MOS7720_FCR, 0xcf);
1624 
1625 	/* Send the updated LCR value to the mos7720 */
1626 	write_mos_reg(serial, port_number, MOS7720_LCR,
1627 		      mos7720_port->shadowLCR);
1628 	mos7720_port->shadowMCR = 0x0b;
1629 	write_mos_reg(serial, port_number, MOS7720_MCR,
1630 		      mos7720_port->shadowMCR);
1631 
1632 	/* set up the MCR register and send it to the mos7720 */
1633 	mos7720_port->shadowMCR = UART_MCR_OUT2;
1634 	if (cflag & CBAUD)
1635 		mos7720_port->shadowMCR |= (UART_MCR_DTR | UART_MCR_RTS);
1636 
1637 	if (cflag & CRTSCTS) {
1638 		mos7720_port->shadowMCR |= (UART_MCR_XONANY);
1639 		/* To set hardware flow control to the specified *
1640 		 * serial port, in SP1/2_CONTROL_REG             */
1641 		if (port_number)
1642 			write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG,
1643 				      0x01);
1644 		else
1645 			write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG,
1646 				      0x02);
1647 
1648 	} else
1649 		mos7720_port->shadowMCR &= ~(UART_MCR_XONANY);
1650 
1651 	write_mos_reg(serial, port_number, MOS7720_MCR,
1652 		      mos7720_port->shadowMCR);
1653 
1654 	/* Determine divisor based on baud rate */
1655 	baud = tty_get_baud_rate(tty);
1656 	if (!baud) {
1657 		/* pick a default, any default... */
1658 		dev_dbg(&port->dev, "Picked default baud...\n");
1659 		baud = 9600;
1660 	}
1661 
1662 	if (baud >= 230400) {
1663 		set_higher_rates(mos7720_port, baud);
1664 		/* Enable Interrupts */
1665 		write_mos_reg(serial, port_number, MOS7720_IER, 0x0c);
1666 		return;
1667 	}
1668 
1669 	dev_dbg(&port->dev, "%s - baud rate = %d\n", __func__, baud);
1670 	status = send_cmd_write_baud_rate(mos7720_port, baud);
1671 	/* FIXME: needs to write actual resulting baud back not just
1672 	   blindly do so */
1673 	if (cflag & CBAUD)
1674 		tty_encode_baud_rate(tty, baud, baud);
1675 	/* Enable Interrupts */
1676 	write_mos_reg(serial, port_number, MOS7720_IER, 0x0c);
1677 
1678 	if (port->read_urb->status != -EINPROGRESS) {
1679 		status = usb_submit_urb(port->read_urb, GFP_KERNEL);
1680 		if (status)
1681 			dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, status = %d\n", status);
1682 	}
1683 }
1684 
1685 /*
1686  * mos7720_set_termios
1687  *	this function is called by the tty driver when it wants to change the
1688  *	termios structure.
1689  */
1690 static void mos7720_set_termios(struct tty_struct *tty,
1691 		struct usb_serial_port *port, struct ktermios *old_termios)
1692 {
1693 	int status;
1694 	unsigned int cflag;
1695 	struct usb_serial *serial;
1696 	struct moschip_port *mos7720_port;
1697 
1698 	serial = port->serial;
1699 
1700 	mos7720_port = usb_get_serial_port_data(port);
1701 
1702 	if (mos7720_port == NULL)
1703 		return;
1704 
1705 	if (!mos7720_port->open) {
1706 		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
1707 		return;
1708 	}
1709 
1710 	dev_dbg(&port->dev, "setting termios - ASPIRE\n");
1711 
1712 	cflag = tty->termios.c_cflag;
1713 
1714 	dev_dbg(&port->dev, "%s - cflag %08x iflag %08x\n", __func__,
1715 		tty->termios.c_cflag, RELEVANT_IFLAG(tty->termios.c_iflag));
1716 
1717 	dev_dbg(&port->dev, "%s - old cflag %08x old iflag %08x\n", __func__,
1718 		old_termios->c_cflag, RELEVANT_IFLAG(old_termios->c_iflag));
1719 
1720 	/* change the port settings to the new ones specified */
1721 	change_port_settings(tty, mos7720_port, old_termios);
1722 
1723 	if (port->read_urb->status != -EINPROGRESS) {
1724 		status = usb_submit_urb(port->read_urb, GFP_KERNEL);
1725 		if (status)
1726 			dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, status = %d\n", status);
1727 	}
1728 }
1729 
1730 /*
1731  * get_lsr_info - get line status register info
1732  *
1733  * Purpose: Let user call ioctl() to get info when the UART physically
1734  * 	    is emptied.  On bus types like RS485, the transmitter must
1735  * 	    release the bus after transmitting. This must be done when
1736  * 	    the transmit shift register is empty, not be done when the
1737  * 	    transmit holding register is empty.  This functionality
1738  * 	    allows an RS485 driver to be written in user space.
1739  */
1740 static int get_lsr_info(struct tty_struct *tty,
1741 		struct moschip_port *mos7720_port, unsigned int __user *value)
1742 {
1743 	struct usb_serial_port *port = tty->driver_data;
1744 	unsigned int result = 0;
1745 	unsigned char data = 0;
1746 	int port_number = port->port_number;
1747 	int count;
1748 
1749 	count = mos7720_chars_in_buffer(tty);
1750 	if (count == 0) {
1751 		read_mos_reg(port->serial, port_number, MOS7720_LSR, &data);
1752 		if ((data & (UART_LSR_TEMT | UART_LSR_THRE))
1753 					== (UART_LSR_TEMT | UART_LSR_THRE)) {
1754 			dev_dbg(&port->dev, "%s -- Empty\n", __func__);
1755 			result = TIOCSER_TEMT;
1756 		}
1757 	}
1758 	if (copy_to_user(value, &result, sizeof(int)))
1759 		return -EFAULT;
1760 	return 0;
1761 }
1762 
1763 static int mos7720_tiocmget(struct tty_struct *tty)
1764 {
1765 	struct usb_serial_port *port = tty->driver_data;
1766 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
1767 	unsigned int result = 0;
1768 	unsigned int mcr ;
1769 	unsigned int msr ;
1770 
1771 	mcr = mos7720_port->shadowMCR;
1772 	msr = mos7720_port->shadowMSR;
1773 
1774 	result = ((mcr & UART_MCR_DTR)  ? TIOCM_DTR : 0)   /* 0x002 */
1775 	  | ((mcr & UART_MCR_RTS)   ? TIOCM_RTS : 0)   /* 0x004 */
1776 	  | ((msr & UART_MSR_CTS)   ? TIOCM_CTS : 0)   /* 0x020 */
1777 	  | ((msr & UART_MSR_DCD)   ? TIOCM_CAR : 0)   /* 0x040 */
1778 	  | ((msr & UART_MSR_RI)    ? TIOCM_RI :  0)   /* 0x080 */
1779 	  | ((msr & UART_MSR_DSR)   ? TIOCM_DSR : 0);  /* 0x100 */
1780 
1781 	return result;
1782 }
1783 
1784 static int mos7720_tiocmset(struct tty_struct *tty,
1785 			    unsigned int set, unsigned int clear)
1786 {
1787 	struct usb_serial_port *port = tty->driver_data;
1788 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
1789 	unsigned int mcr ;
1790 
1791 	mcr = mos7720_port->shadowMCR;
1792 
1793 	if (set & TIOCM_RTS)
1794 		mcr |= UART_MCR_RTS;
1795 	if (set & TIOCM_DTR)
1796 		mcr |= UART_MCR_DTR;
1797 	if (set & TIOCM_LOOP)
1798 		mcr |= UART_MCR_LOOP;
1799 
1800 	if (clear & TIOCM_RTS)
1801 		mcr &= ~UART_MCR_RTS;
1802 	if (clear & TIOCM_DTR)
1803 		mcr &= ~UART_MCR_DTR;
1804 	if (clear & TIOCM_LOOP)
1805 		mcr &= ~UART_MCR_LOOP;
1806 
1807 	mos7720_port->shadowMCR = mcr;
1808 	write_mos_reg(port->serial, port->port_number, MOS7720_MCR,
1809 		      mos7720_port->shadowMCR);
1810 
1811 	return 0;
1812 }
1813 
1814 static int set_modem_info(struct moschip_port *mos7720_port, unsigned int cmd,
1815 			  unsigned int __user *value)
1816 {
1817 	unsigned int mcr;
1818 	unsigned int arg;
1819 
1820 	struct usb_serial_port *port;
1821 
1822 	if (mos7720_port == NULL)
1823 		return -1;
1824 
1825 	port = (struct usb_serial_port *)mos7720_port->port;
1826 	mcr = mos7720_port->shadowMCR;
1827 
1828 	if (copy_from_user(&arg, value, sizeof(int)))
1829 		return -EFAULT;
1830 
1831 	switch (cmd) {
1832 	case TIOCMBIS:
1833 		if (arg & TIOCM_RTS)
1834 			mcr |= UART_MCR_RTS;
1835 		if (arg & TIOCM_DTR)
1836 			mcr |= UART_MCR_RTS;
1837 		if (arg & TIOCM_LOOP)
1838 			mcr |= UART_MCR_LOOP;
1839 		break;
1840 
1841 	case TIOCMBIC:
1842 		if (arg & TIOCM_RTS)
1843 			mcr &= ~UART_MCR_RTS;
1844 		if (arg & TIOCM_DTR)
1845 			mcr &= ~UART_MCR_RTS;
1846 		if (arg & TIOCM_LOOP)
1847 			mcr &= ~UART_MCR_LOOP;
1848 		break;
1849 
1850 	}
1851 
1852 	mos7720_port->shadowMCR = mcr;
1853 	write_mos_reg(port->serial, port->port_number, MOS7720_MCR,
1854 		      mos7720_port->shadowMCR);
1855 
1856 	return 0;
1857 }
1858 
1859 static int get_serial_info(struct moschip_port *mos7720_port,
1860 			   struct serial_struct __user *retinfo)
1861 {
1862 	struct serial_struct tmp;
1863 
1864 	if (!retinfo)
1865 		return -EFAULT;
1866 
1867 	memset(&tmp, 0, sizeof(tmp));
1868 
1869 	tmp.type		= PORT_16550A;
1870 	tmp.line		= mos7720_port->port->minor;
1871 	tmp.port		= mos7720_port->port->port_number;
1872 	tmp.irq			= 0;
1873 	tmp.flags		= ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
1874 	tmp.xmit_fifo_size	= NUM_URBS * URB_TRANSFER_BUFFER_SIZE;
1875 	tmp.baud_base		= 9600;
1876 	tmp.close_delay		= 5*HZ;
1877 	tmp.closing_wait	= 30*HZ;
1878 
1879 	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
1880 		return -EFAULT;
1881 	return 0;
1882 }
1883 
1884 static int mos7720_ioctl(struct tty_struct *tty,
1885 			 unsigned int cmd, unsigned long arg)
1886 {
1887 	struct usb_serial_port *port = tty->driver_data;
1888 	struct moschip_port *mos7720_port;
1889 
1890 	mos7720_port = usb_get_serial_port_data(port);
1891 	if (mos7720_port == NULL)
1892 		return -ENODEV;
1893 
1894 	switch (cmd) {
1895 	case TIOCSERGETLSR:
1896 		dev_dbg(&port->dev, "%s TIOCSERGETLSR\n", __func__);
1897 		return get_lsr_info(tty, mos7720_port,
1898 					(unsigned int __user *)arg);
1899 
1900 	/* FIXME: These should be using the mode methods */
1901 	case TIOCMBIS:
1902 	case TIOCMBIC:
1903 		dev_dbg(&port->dev, "%s TIOCMSET/TIOCMBIC/TIOCMSET\n", __func__);
1904 		return set_modem_info(mos7720_port, cmd,
1905 				      (unsigned int __user *)arg);
1906 
1907 	case TIOCGSERIAL:
1908 		dev_dbg(&port->dev, "%s TIOCGSERIAL\n", __func__);
1909 		return get_serial_info(mos7720_port,
1910 				       (struct serial_struct __user *)arg);
1911 	}
1912 
1913 	return -ENOIOCTLCMD;
1914 }
1915 
1916 static int mos7720_startup(struct usb_serial *serial)
1917 {
1918 	struct usb_device *dev;
1919 	char data;
1920 	u16 product;
1921 	int ret_val;
1922 
1923 	product = le16_to_cpu(serial->dev->descriptor.idProduct);
1924 	dev = serial->dev;
1925 
1926 	/*
1927 	 * The 7715 uses the first bulk in/out endpoint pair for the parallel
1928 	 * port, and the second for the serial port.  Because the usbserial core
1929 	 * assumes both pairs are serial ports, we must engage in a bit of
1930 	 * subterfuge and swap the pointers for ports 0 and 1 in order to make
1931 	 * port 0 point to the serial port.  However, both moschip devices use a
1932 	 * single interrupt-in endpoint for both ports (as mentioned a little
1933 	 * further down), and this endpoint was assigned to port 0.  So after
1934 	 * the swap, we must copy the interrupt endpoint elements from port 1
1935 	 * (as newly assigned) to port 0, and null out port 1 pointers.
1936 	 */
1937 	if (product == MOSCHIP_DEVICE_ID_7715) {
1938 		struct usb_serial_port *tmp = serial->port[0];
1939 		serial->port[0] = serial->port[1];
1940 		serial->port[1] = tmp;
1941 		serial->port[0]->interrupt_in_urb = tmp->interrupt_in_urb;
1942 		serial->port[0]->interrupt_in_buffer = tmp->interrupt_in_buffer;
1943 		serial->port[0]->interrupt_in_endpointAddress =
1944 			tmp->interrupt_in_endpointAddress;
1945 		serial->port[1]->interrupt_in_urb = NULL;
1946 		serial->port[1]->interrupt_in_buffer = NULL;
1947 	}
1948 
1949 	/* setting configuration feature to one */
1950 	usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
1951 			(__u8)0x03, 0x00, 0x01, 0x00, NULL, 0x00, 5000);
1952 
1953 	/* start the interrupt urb */
1954 	ret_val = usb_submit_urb(serial->port[0]->interrupt_in_urb, GFP_KERNEL);
1955 	if (ret_val)
1956 		dev_err(&dev->dev,
1957 			"%s - Error %d submitting control urb\n",
1958 			__func__, ret_val);
1959 
1960 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
1961 	if (product == MOSCHIP_DEVICE_ID_7715) {
1962 		ret_val = mos7715_parport_init(serial);
1963 		if (ret_val < 0)
1964 			return ret_val;
1965 	}
1966 #endif
1967 	/* LSR For Port 1 */
1968 	read_mos_reg(serial, 0, MOS7720_LSR, &data);
1969 	dev_dbg(&dev->dev, "LSR:%x\n", data);
1970 
1971 	return 0;
1972 }
1973 
1974 static void mos7720_release(struct usb_serial *serial)
1975 {
1976 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
1977 	/* close the parallel port */
1978 
1979 	if (le16_to_cpu(serial->dev->descriptor.idProduct)
1980 	    == MOSCHIP_DEVICE_ID_7715) {
1981 		struct urbtracker *urbtrack;
1982 		unsigned long flags;
1983 		struct mos7715_parport *mos_parport =
1984 			usb_get_serial_data(serial);
1985 
1986 		/* prevent NULL ptr dereference in port callbacks */
1987 		spin_lock(&release_lock);
1988 		mos_parport->pp->private_data = NULL;
1989 		spin_unlock(&release_lock);
1990 
1991 		/* wait for synchronous usb calls to return */
1992 		if (mos_parport->msg_pending)
1993 			wait_for_completion_timeout(&mos_parport->syncmsg_compl,
1994 					    msecs_to_jiffies(MOS_WDR_TIMEOUT));
1995 
1996 		parport_remove_port(mos_parport->pp);
1997 		usb_set_serial_data(serial, NULL);
1998 		mos_parport->serial = NULL;
1999 
2000 		/* if tasklet currently scheduled, wait for it to complete */
2001 		tasklet_kill(&mos_parport->urb_tasklet);
2002 
2003 		/* unlink any urbs sent by the tasklet  */
2004 		spin_lock_irqsave(&mos_parport->listlock, flags);
2005 		list_for_each_entry(urbtrack,
2006 				    &mos_parport->active_urbs,
2007 				    urblist_entry)
2008 			usb_unlink_urb(urbtrack->urb);
2009 		spin_unlock_irqrestore(&mos_parport->listlock, flags);
2010 
2011 		kref_put(&mos_parport->ref_count, destroy_mos_parport);
2012 	}
2013 #endif
2014 }
2015 
2016 static int mos7720_port_probe(struct usb_serial_port *port)
2017 {
2018 	struct moschip_port *mos7720_port;
2019 
2020 	mos7720_port = kzalloc(sizeof(*mos7720_port), GFP_KERNEL);
2021 	if (!mos7720_port)
2022 		return -ENOMEM;
2023 
2024 	/* Initialize all port interrupt end point to port 0 int endpoint.
2025 	 * Our device has only one interrupt endpoint common to all ports.
2026 	 */
2027 	port->interrupt_in_endpointAddress =
2028 		port->serial->port[0]->interrupt_in_endpointAddress;
2029 	mos7720_port->port = port;
2030 
2031 	usb_set_serial_port_data(port, mos7720_port);
2032 
2033 	return 0;
2034 }
2035 
2036 static int mos7720_port_remove(struct usb_serial_port *port)
2037 {
2038 	struct moschip_port *mos7720_port;
2039 
2040 	mos7720_port = usb_get_serial_port_data(port);
2041 	kfree(mos7720_port);
2042 
2043 	return 0;
2044 }
2045 
2046 static struct usb_serial_driver moschip7720_2port_driver = {
2047 	.driver = {
2048 		.owner =	THIS_MODULE,
2049 		.name =		"moschip7720",
2050 	},
2051 	.description		= "Moschip 2 port adapter",
2052 	.id_table		= id_table,
2053 	.calc_num_ports		= mos77xx_calc_num_ports,
2054 	.open			= mos7720_open,
2055 	.close			= mos7720_close,
2056 	.throttle		= mos7720_throttle,
2057 	.unthrottle		= mos7720_unthrottle,
2058 	.probe			= mos77xx_probe,
2059 	.attach			= mos7720_startup,
2060 	.release		= mos7720_release,
2061 	.port_probe		= mos7720_port_probe,
2062 	.port_remove		= mos7720_port_remove,
2063 	.ioctl			= mos7720_ioctl,
2064 	.tiocmget		= mos7720_tiocmget,
2065 	.tiocmset		= mos7720_tiocmset,
2066 	.set_termios		= mos7720_set_termios,
2067 	.write			= mos7720_write,
2068 	.write_room		= mos7720_write_room,
2069 	.chars_in_buffer	= mos7720_chars_in_buffer,
2070 	.break_ctl		= mos7720_break,
2071 	.read_bulk_callback	= mos7720_bulk_in_callback,
2072 	.read_int_callback	= NULL  /* dynamically assigned in probe() */
2073 };
2074 
2075 static struct usb_serial_driver * const serial_drivers[] = {
2076 	&moschip7720_2port_driver, NULL
2077 };
2078 
2079 module_usb_serial_driver(serial_drivers, id_table);
2080 
2081 MODULE_AUTHOR(DRIVER_AUTHOR);
2082 MODULE_DESCRIPTION(DRIVER_DESC);
2083 MODULE_LICENSE("GPL");
2084