xref: /linux/drivers/usb/serial/mos7720.c (revision 4f77c3462308c62ffe7129cc18b9ac937f44b5a5)
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 enum mos7715_pp_modes {
83 	SPP = 0<<5,
84 	PS2 = 1<<5,      /* moschip calls this 'NIBBLE' mode */
85 	PPF = 2<<5,	 /* moschip calls this 'CB-FIFO mode */
86 };
87 
88 struct mos7715_parport {
89 	struct parport          *pp;	       /* back to containing struct */
90 	struct kref             ref_count;     /* to instance of this struct */
91 	bool                    msg_pending;   /* usb sync call pending */
92 	struct completion       syncmsg_compl; /* usb sync call completed */
93 	struct work_struct      work;          /* restore deferred writes */
94 	struct usb_serial       *serial;       /* back to containing struct */
95 	__u8	                shadowECR;     /* parallel port regs... */
96 	__u8	                shadowDCR;
97 	atomic_t                shadowDSR;     /* updated in int-in callback */
98 };
99 
100 /* lock guards against dereferencing NULL ptr in parport ops callbacks */
101 static DEFINE_SPINLOCK(release_lock);
102 
103 #endif	/* CONFIG_USB_SERIAL_MOS7715_PARPORT */
104 
105 static const unsigned int dummy; /* for clarity in register access fns */
106 
107 enum mos_regs {
108 	MOS7720_THR,		  /* serial port regs */
109 	MOS7720_RHR,
110 	MOS7720_IER,
111 	MOS7720_FCR,
112 	MOS7720_ISR,
113 	MOS7720_LCR,
114 	MOS7720_MCR,
115 	MOS7720_LSR,
116 	MOS7720_MSR,
117 	MOS7720_SPR,
118 	MOS7720_DLL,
119 	MOS7720_DLM,
120 	MOS7720_DPR,		  /* parallel port regs */
121 	MOS7720_DSR,
122 	MOS7720_DCR,
123 	MOS7720_ECR,
124 	MOS7720_SP1_REG,	  /* device control regs */
125 	MOS7720_SP2_REG,	  /* serial port 2 (7720 only) */
126 	MOS7720_PP_REG,
127 	MOS7720_SP_CONTROL_REG,
128 };
129 
130 /*
131  * Return the correct value for the Windex field of the setup packet
132  * for a control endpoint message.  See the 7715 datasheet.
133  */
134 static inline __u16 get_reg_index(enum mos_regs reg)
135 {
136 	static const __u16 mos7715_index_lookup_table[] = {
137 		0x00,		/* MOS7720_THR */
138 		0x00,		/* MOS7720_RHR */
139 		0x01,		/* MOS7720_IER */
140 		0x02,		/* MOS7720_FCR */
141 		0x02,		/* MOS7720_ISR */
142 		0x03,		/* MOS7720_LCR */
143 		0x04,		/* MOS7720_MCR */
144 		0x05,		/* MOS7720_LSR */
145 		0x06,		/* MOS7720_MSR */
146 		0x07,		/* MOS7720_SPR */
147 		0x00,		/* MOS7720_DLL */
148 		0x01,		/* MOS7720_DLM */
149 		0x00,		/* MOS7720_DPR */
150 		0x01,		/* MOS7720_DSR */
151 		0x02,		/* MOS7720_DCR */
152 		0x0a,		/* MOS7720_ECR */
153 		0x01,		/* MOS7720_SP1_REG */
154 		0x02,		/* MOS7720_SP2_REG (7720 only) */
155 		0x04,		/* MOS7720_PP_REG (7715 only) */
156 		0x08,		/* MOS7720_SP_CONTROL_REG */
157 	};
158 	return mos7715_index_lookup_table[reg];
159 }
160 
161 /*
162  * Return the correct value for the upper byte of the Wvalue field of
163  * the setup packet for a control endpoint message.
164  */
165 static inline __u16 get_reg_value(enum mos_regs reg,
166 				  unsigned int serial_portnum)
167 {
168 	if (reg >= MOS7720_SP1_REG)	/* control reg */
169 		return 0x0000;
170 
171 	else if (reg >= MOS7720_DPR)	/* parallel port reg (7715 only) */
172 		return 0x0100;
173 
174 	else			      /* serial port reg */
175 		return (serial_portnum + 2) << 8;
176 }
177 
178 /*
179  * Write data byte to the specified device register.  The data is embedded in
180  * the value field of the setup packet. serial_portnum is ignored for registers
181  * not specific to a particular serial port.
182  */
183 static int write_mos_reg(struct usb_serial *serial, unsigned int serial_portnum,
184 			 enum mos_regs reg, __u8 data)
185 {
186 	struct usb_device *usbdev = serial->dev;
187 	unsigned int pipe = usb_sndctrlpipe(usbdev, 0);
188 	__u8 request = (__u8)0x0e;
189 	__u8 requesttype = (__u8)0x40;
190 	__u16 index = get_reg_index(reg);
191 	__u16 value = get_reg_value(reg, serial_portnum) + data;
192 	int status = usb_control_msg(usbdev, pipe, request, requesttype, value,
193 				     index, NULL, 0, MOS_WDR_TIMEOUT);
194 	if (status < 0)
195 		dev_err(&usbdev->dev,
196 			"mos7720: usb_control_msg() failed: %d\n", status);
197 	return status;
198 }
199 
200 /*
201  * Read data byte from the specified device register.  The data returned by the
202  * device is embedded in the value field of the setup packet.  serial_portnum is
203  * ignored for registers that are not specific to a particular serial port.
204  */
205 static int read_mos_reg(struct usb_serial *serial, unsigned int serial_portnum,
206 			enum mos_regs reg, __u8 *data)
207 {
208 	struct usb_device *usbdev = serial->dev;
209 	unsigned int pipe = usb_rcvctrlpipe(usbdev, 0);
210 	__u8 request = (__u8)0x0d;
211 	__u8 requesttype = (__u8)0xc0;
212 	__u16 index = get_reg_index(reg);
213 	__u16 value = get_reg_value(reg, serial_portnum);
214 	u8 *buf;
215 	int status;
216 
217 	buf = kmalloc(1, GFP_KERNEL);
218 	if (!buf) {
219 		*data = 0;
220 		return -ENOMEM;
221 	}
222 
223 	status = usb_control_msg(usbdev, pipe, request, requesttype, value,
224 				     index, buf, 1, MOS_WDR_TIMEOUT);
225 	if (status == 1) {
226 		*data = *buf;
227 	} else {
228 		dev_err(&usbdev->dev,
229 			"mos7720: usb_control_msg() failed: %d\n", status);
230 		if (status >= 0)
231 			status = -EIO;
232 		*data = 0;
233 	}
234 
235 	kfree(buf);
236 
237 	return status;
238 }
239 
240 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
241 
242 static inline int mos7715_change_mode(struct mos7715_parport *mos_parport,
243 				      enum mos7715_pp_modes mode)
244 {
245 	mos_parport->shadowECR = mode;
246 	write_mos_reg(mos_parport->serial, dummy, MOS7720_ECR,
247 		      mos_parport->shadowECR);
248 	return 0;
249 }
250 
251 static void destroy_mos_parport(struct kref *kref)
252 {
253 	struct mos7715_parport *mos_parport =
254 		container_of(kref, struct mos7715_parport, ref_count);
255 
256 	kfree(mos_parport);
257 }
258 
259 /*
260  * This is the common top part of all parallel port callback operations that
261  * send synchronous messages to the device.  This implements convoluted locking
262  * that avoids two scenarios: (1) a port operation is called after usbserial
263  * has called our release function, at which point struct mos7715_parport has
264  * been destroyed, and (2) the device has been disconnected, but usbserial has
265  * not called the release function yet because someone has a serial port open.
266  * The shared release_lock prevents the first, and the mutex and disconnected
267  * flag maintained by usbserial covers the second.  We also use the msg_pending
268  * flag to ensure that all synchronous usb message calls have completed before
269  * our release function can return.
270  */
271 static int parport_prologue(struct parport *pp)
272 {
273 	struct mos7715_parport *mos_parport;
274 
275 	spin_lock(&release_lock);
276 	mos_parport = pp->private_data;
277 	if (unlikely(mos_parport == NULL)) {
278 		/* release fn called, port struct destroyed */
279 		spin_unlock(&release_lock);
280 		return -1;
281 	}
282 	mos_parport->msg_pending = true;   /* synch usb call pending */
283 	reinit_completion(&mos_parport->syncmsg_compl);
284 	spin_unlock(&release_lock);
285 
286 	/* ensure writes from restore are submitted before new requests */
287 	if (work_pending(&mos_parport->work))
288 		flush_work(&mos_parport->work);
289 
290 	mutex_lock(&mos_parport->serial->disc_mutex);
291 	if (mos_parport->serial->disconnected) {
292 		/* device disconnected */
293 		mutex_unlock(&mos_parport->serial->disc_mutex);
294 		mos_parport->msg_pending = false;
295 		complete(&mos_parport->syncmsg_compl);
296 		return -1;
297 	}
298 
299 	return 0;
300 }
301 
302 /*
303  * This is the common bottom part of all parallel port functions that send
304  * synchronous messages to the device.
305  */
306 static inline void parport_epilogue(struct parport *pp)
307 {
308 	struct mos7715_parport *mos_parport = pp->private_data;
309 	mutex_unlock(&mos_parport->serial->disc_mutex);
310 	mos_parport->msg_pending = false;
311 	complete(&mos_parport->syncmsg_compl);
312 }
313 
314 static void deferred_restore_writes(struct work_struct *work)
315 {
316 	struct mos7715_parport *mos_parport;
317 
318 	mos_parport = container_of(work, struct mos7715_parport, work);
319 
320 	mutex_lock(&mos_parport->serial->disc_mutex);
321 
322 	/* if device disconnected, game over */
323 	if (mos_parport->serial->disconnected)
324 		goto done;
325 
326 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
327 		      mos_parport->shadowDCR);
328 	write_mos_reg(mos_parport->serial, dummy, MOS7720_ECR,
329 		      mos_parport->shadowECR);
330 done:
331 	mutex_unlock(&mos_parport->serial->disc_mutex);
332 }
333 
334 static void parport_mos7715_write_data(struct parport *pp, unsigned char d)
335 {
336 	struct mos7715_parport *mos_parport = pp->private_data;
337 
338 	if (parport_prologue(pp) < 0)
339 		return;
340 	mos7715_change_mode(mos_parport, SPP);
341 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DPR, (__u8)d);
342 	parport_epilogue(pp);
343 }
344 
345 static unsigned char parport_mos7715_read_data(struct parport *pp)
346 {
347 	struct mos7715_parport *mos_parport = pp->private_data;
348 	unsigned char d;
349 
350 	if (parport_prologue(pp) < 0)
351 		return 0;
352 	read_mos_reg(mos_parport->serial, dummy, MOS7720_DPR, &d);
353 	parport_epilogue(pp);
354 	return d;
355 }
356 
357 static void parport_mos7715_write_control(struct parport *pp, unsigned char d)
358 {
359 	struct mos7715_parport *mos_parport = pp->private_data;
360 	__u8 data;
361 
362 	if (parport_prologue(pp) < 0)
363 		return;
364 	data = ((__u8)d & 0x0f) | (mos_parport->shadowDCR & 0xf0);
365 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR, data);
366 	mos_parport->shadowDCR = data;
367 	parport_epilogue(pp);
368 }
369 
370 static unsigned char parport_mos7715_read_control(struct parport *pp)
371 {
372 	struct mos7715_parport *mos_parport;
373 	__u8 dcr;
374 
375 	spin_lock(&release_lock);
376 	mos_parport = pp->private_data;
377 	if (unlikely(mos_parport == NULL)) {
378 		spin_unlock(&release_lock);
379 		return 0;
380 	}
381 	dcr = mos_parport->shadowDCR & 0x0f;
382 	spin_unlock(&release_lock);
383 	return dcr;
384 }
385 
386 static unsigned char parport_mos7715_frob_control(struct parport *pp,
387 						  unsigned char mask,
388 						  unsigned char val)
389 {
390 	struct mos7715_parport *mos_parport = pp->private_data;
391 	__u8 dcr;
392 
393 	mask &= 0x0f;
394 	val &= 0x0f;
395 	if (parport_prologue(pp) < 0)
396 		return 0;
397 	mos_parport->shadowDCR = (mos_parport->shadowDCR & (~mask)) ^ val;
398 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
399 		      mos_parport->shadowDCR);
400 	dcr = mos_parport->shadowDCR & 0x0f;
401 	parport_epilogue(pp);
402 	return dcr;
403 }
404 
405 static unsigned char parport_mos7715_read_status(struct parport *pp)
406 {
407 	unsigned char status;
408 	struct mos7715_parport *mos_parport;
409 
410 	spin_lock(&release_lock);
411 	mos_parport = pp->private_data;
412 	if (unlikely(mos_parport == NULL)) {	/* release called */
413 		spin_unlock(&release_lock);
414 		return 0;
415 	}
416 	status = atomic_read(&mos_parport->shadowDSR) & 0xf8;
417 	spin_unlock(&release_lock);
418 	return status;
419 }
420 
421 static void parport_mos7715_enable_irq(struct parport *pp)
422 {
423 }
424 
425 static void parport_mos7715_disable_irq(struct parport *pp)
426 {
427 }
428 
429 static void parport_mos7715_data_forward(struct parport *pp)
430 {
431 	struct mos7715_parport *mos_parport = pp->private_data;
432 
433 	if (parport_prologue(pp) < 0)
434 		return;
435 	mos7715_change_mode(mos_parport, PS2);
436 	mos_parport->shadowDCR &=  ~0x20;
437 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
438 		      mos_parport->shadowDCR);
439 	parport_epilogue(pp);
440 }
441 
442 static void parport_mos7715_data_reverse(struct parport *pp)
443 {
444 	struct mos7715_parport *mos_parport = pp->private_data;
445 
446 	if (parport_prologue(pp) < 0)
447 		return;
448 	mos7715_change_mode(mos_parport, PS2);
449 	mos_parport->shadowDCR |= 0x20;
450 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
451 		      mos_parport->shadowDCR);
452 	parport_epilogue(pp);
453 }
454 
455 static void parport_mos7715_init_state(struct pardevice *dev,
456 				       struct parport_state *s)
457 {
458 	s->u.pc.ctr = DCR_INIT_VAL;
459 	s->u.pc.ecr = ECR_INIT_VAL;
460 }
461 
462 /* N.B. Parport core code requires that this function not block */
463 static void parport_mos7715_save_state(struct parport *pp,
464 				       struct parport_state *s)
465 {
466 	struct mos7715_parport *mos_parport;
467 
468 	spin_lock(&release_lock);
469 	mos_parport = pp->private_data;
470 	if (unlikely(mos_parport == NULL)) {	/* release called */
471 		spin_unlock(&release_lock);
472 		return;
473 	}
474 	s->u.pc.ctr = mos_parport->shadowDCR;
475 	s->u.pc.ecr = mos_parport->shadowECR;
476 	spin_unlock(&release_lock);
477 }
478 
479 /* N.B. Parport core code requires that this function not block */
480 static void parport_mos7715_restore_state(struct parport *pp,
481 					  struct parport_state *s)
482 {
483 	struct mos7715_parport *mos_parport;
484 
485 	spin_lock(&release_lock);
486 	mos_parport = pp->private_data;
487 	if (unlikely(mos_parport == NULL)) {	/* release called */
488 		spin_unlock(&release_lock);
489 		return;
490 	}
491 	mos_parport->shadowDCR = s->u.pc.ctr;
492 	mos_parport->shadowECR = s->u.pc.ecr;
493 
494 	schedule_work(&mos_parport->work);
495 	spin_unlock(&release_lock);
496 }
497 
498 static size_t parport_mos7715_write_compat(struct parport *pp,
499 					   const void *buffer,
500 					   size_t len, int flags)
501 {
502 	int retval;
503 	struct mos7715_parport *mos_parport = pp->private_data;
504 	int actual_len;
505 
506 	if (parport_prologue(pp) < 0)
507 		return 0;
508 	mos7715_change_mode(mos_parport, PPF);
509 	retval = usb_bulk_msg(mos_parport->serial->dev,
510 			      usb_sndbulkpipe(mos_parport->serial->dev, 2),
511 			      (void *)buffer, len, &actual_len,
512 			      MOS_WDR_TIMEOUT);
513 	parport_epilogue(pp);
514 	if (retval) {
515 		dev_err(&mos_parport->serial->dev->dev,
516 			"mos7720: usb_bulk_msg() failed: %d\n", retval);
517 		return 0;
518 	}
519 	return actual_len;
520 }
521 
522 static struct parport_operations parport_mos7715_ops = {
523 	.owner =		THIS_MODULE,
524 	.write_data =		parport_mos7715_write_data,
525 	.read_data =		parport_mos7715_read_data,
526 
527 	.write_control =	parport_mos7715_write_control,
528 	.read_control =		parport_mos7715_read_control,
529 	.frob_control =		parport_mos7715_frob_control,
530 
531 	.read_status =		parport_mos7715_read_status,
532 
533 	.enable_irq =		parport_mos7715_enable_irq,
534 	.disable_irq =		parport_mos7715_disable_irq,
535 
536 	.data_forward =		parport_mos7715_data_forward,
537 	.data_reverse =		parport_mos7715_data_reverse,
538 
539 	.init_state =		parport_mos7715_init_state,
540 	.save_state =		parport_mos7715_save_state,
541 	.restore_state =	parport_mos7715_restore_state,
542 
543 	.compat_write_data =	parport_mos7715_write_compat,
544 
545 	.nibble_read_data =	parport_ieee1284_read_nibble,
546 	.byte_read_data =	parport_ieee1284_read_byte,
547 };
548 
549 /*
550  * Allocate and initialize parallel port control struct, initialize
551  * the parallel port hardware device, and register with the parport subsystem.
552  */
553 static int mos7715_parport_init(struct usb_serial *serial)
554 {
555 	struct mos7715_parport *mos_parport;
556 
557 	/* allocate and initialize parallel port control struct */
558 	mos_parport = kzalloc(sizeof(struct mos7715_parport), GFP_KERNEL);
559 	if (!mos_parport)
560 		return -ENOMEM;
561 
562 	mos_parport->msg_pending = false;
563 	kref_init(&mos_parport->ref_count);
564 	usb_set_serial_data(serial, mos_parport); /* hijack private pointer */
565 	mos_parport->serial = serial;
566 	INIT_WORK(&mos_parport->work, deferred_restore_writes);
567 	init_completion(&mos_parport->syncmsg_compl);
568 
569 	/* cycle parallel port reset bit */
570 	write_mos_reg(mos_parport->serial, dummy, MOS7720_PP_REG, (__u8)0x80);
571 	write_mos_reg(mos_parport->serial, dummy, MOS7720_PP_REG, (__u8)0x00);
572 
573 	/* initialize device registers */
574 	mos_parport->shadowDCR = DCR_INIT_VAL;
575 	write_mos_reg(mos_parport->serial, dummy, MOS7720_DCR,
576 		      mos_parport->shadowDCR);
577 	mos_parport->shadowECR = ECR_INIT_VAL;
578 	write_mos_reg(mos_parport->serial, dummy, MOS7720_ECR,
579 		      mos_parport->shadowECR);
580 
581 	/* register with parport core */
582 	mos_parport->pp = parport_register_port(0, PARPORT_IRQ_NONE,
583 						PARPORT_DMA_NONE,
584 						&parport_mos7715_ops);
585 	if (mos_parport->pp == NULL) {
586 		dev_err(&serial->interface->dev,
587 			"Could not register parport\n");
588 		kref_put(&mos_parport->ref_count, destroy_mos_parport);
589 		return -EIO;
590 	}
591 	mos_parport->pp->private_data = mos_parport;
592 	mos_parport->pp->modes = PARPORT_MODE_COMPAT | PARPORT_MODE_PCSPP;
593 	mos_parport->pp->dev = &serial->interface->dev;
594 	parport_announce_port(mos_parport->pp);
595 
596 	return 0;
597 }
598 #endif	/* CONFIG_USB_SERIAL_MOS7715_PARPORT */
599 
600 /*
601  * mos7720_interrupt_callback
602  *	this is the callback function for when we have received data on the
603  *	interrupt endpoint.
604  */
605 static void mos7720_interrupt_callback(struct urb *urb)
606 {
607 	int result;
608 	int length;
609 	int status = urb->status;
610 	struct device *dev = &urb->dev->dev;
611 	__u8 *data;
612 	__u8 sp1;
613 	__u8 sp2;
614 
615 	switch (status) {
616 	case 0:
617 		/* success */
618 		break;
619 	case -ECONNRESET:
620 	case -ENOENT:
621 	case -ESHUTDOWN:
622 		/* this urb is terminated, clean up */
623 		dev_dbg(dev, "%s - urb shutting down with status: %d\n", __func__, status);
624 		return;
625 	default:
626 		dev_dbg(dev, "%s - nonzero urb status received: %d\n", __func__, status);
627 		goto exit;
628 	}
629 
630 	length = urb->actual_length;
631 	data = urb->transfer_buffer;
632 
633 	/* Moschip get 4 bytes
634 	 * Byte 1 IIR Port 1 (port.number is 0)
635 	 * Byte 2 IIR Port 2 (port.number is 1)
636 	 * Byte 3 --------------
637 	 * Byte 4 FIFO status for both */
638 
639 	/* the above description is inverted
640 	 * 	oneukum 2007-03-14 */
641 
642 	if (unlikely(length != 4)) {
643 		dev_dbg(dev, "Wrong data !!!\n");
644 		return;
645 	}
646 
647 	sp1 = data[3];
648 	sp2 = data[2];
649 
650 	if ((sp1 | sp2) & 0x01) {
651 		/* No Interrupt Pending in both the ports */
652 		dev_dbg(dev, "No Interrupt !!!\n");
653 	} else {
654 		switch (sp1 & 0x0f) {
655 		case SERIAL_IIR_RLS:
656 			dev_dbg(dev, "Serial Port 1: Receiver status error or address bit detected in 9-bit mode\n");
657 			break;
658 		case SERIAL_IIR_CTI:
659 			dev_dbg(dev, "Serial Port 1: Receiver time out\n");
660 			break;
661 		case SERIAL_IIR_MS:
662 			/* dev_dbg(dev, "Serial Port 1: Modem status change\n"); */
663 			break;
664 		}
665 
666 		switch (sp2 & 0x0f) {
667 		case SERIAL_IIR_RLS:
668 			dev_dbg(dev, "Serial Port 2: Receiver status error or address bit detected in 9-bit mode\n");
669 			break;
670 		case SERIAL_IIR_CTI:
671 			dev_dbg(dev, "Serial Port 2: Receiver time out\n");
672 			break;
673 		case SERIAL_IIR_MS:
674 			/* dev_dbg(dev, "Serial Port 2: Modem status change\n"); */
675 			break;
676 		}
677 	}
678 
679 exit:
680 	result = usb_submit_urb(urb, GFP_ATOMIC);
681 	if (result)
682 		dev_err(dev, "%s - Error %d submitting control urb\n", __func__, result);
683 }
684 
685 /*
686  * mos7715_interrupt_callback
687  *	this is the 7715's callback function for when we have received data on
688  *	the interrupt endpoint.
689  */
690 static void mos7715_interrupt_callback(struct urb *urb)
691 {
692 	int result;
693 	int length;
694 	int status = urb->status;
695 	struct device *dev = &urb->dev->dev;
696 	__u8 *data;
697 	__u8 iir;
698 
699 	switch (status) {
700 	case 0:
701 		/* success */
702 		break;
703 	case -ECONNRESET:
704 	case -ENOENT:
705 	case -ESHUTDOWN:
706 	case -ENODEV:
707 		/* this urb is terminated, clean up */
708 		dev_dbg(dev, "%s - urb shutting down with status: %d\n", __func__, status);
709 		return;
710 	default:
711 		dev_dbg(dev, "%s - nonzero urb status received: %d\n", __func__, status);
712 		goto exit;
713 	}
714 
715 	length = urb->actual_length;
716 	data = urb->transfer_buffer;
717 
718 	/* Structure of data from 7715 device:
719 	 * Byte 1: IIR serial Port
720 	 * Byte 2: unused
721 	 * Byte 2: DSR parallel port
722 	 * Byte 4: FIFO status for both */
723 
724 	if (unlikely(length != 4)) {
725 		dev_dbg(dev, "Wrong data !!!\n");
726 		return;
727 	}
728 
729 	iir = data[0];
730 	if (!(iir & 0x01)) {	/* serial port interrupt pending */
731 		switch (iir & 0x0f) {
732 		case SERIAL_IIR_RLS:
733 			dev_dbg(dev, "Serial Port: Receiver status error or address bit detected in 9-bit mode\n");
734 			break;
735 		case SERIAL_IIR_CTI:
736 			dev_dbg(dev, "Serial Port: Receiver time out\n");
737 			break;
738 		case SERIAL_IIR_MS:
739 			/* dev_dbg(dev, "Serial Port: Modem status change\n"); */
740 			break;
741 		}
742 	}
743 
744 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
745 	{       /* update local copy of DSR reg */
746 		struct usb_serial_port *port = urb->context;
747 		struct mos7715_parport *mos_parport = port->serial->private;
748 		if (unlikely(mos_parport == NULL))
749 			return;
750 		atomic_set(&mos_parport->shadowDSR, data[2]);
751 	}
752 #endif
753 
754 exit:
755 	result = usb_submit_urb(urb, GFP_ATOMIC);
756 	if (result)
757 		dev_err(dev, "%s - Error %d submitting control urb\n", __func__, result);
758 }
759 
760 /*
761  * mos7720_bulk_in_callback
762  *	this is the callback function for when we have received data on the
763  *	bulk in endpoint.
764  */
765 static void mos7720_bulk_in_callback(struct urb *urb)
766 {
767 	int retval;
768 	unsigned char *data ;
769 	struct usb_serial_port *port;
770 	int status = urb->status;
771 
772 	if (status) {
773 		dev_dbg(&urb->dev->dev, "nonzero read bulk status received: %d\n", status);
774 		return;
775 	}
776 
777 	port = urb->context;
778 
779 	dev_dbg(&port->dev, "Entering...%s\n", __func__);
780 
781 	data = urb->transfer_buffer;
782 
783 	if (urb->actual_length) {
784 		tty_insert_flip_string(&port->port, data, urb->actual_length);
785 		tty_flip_buffer_push(&port->port);
786 	}
787 
788 	if (port->read_urb->status != -EINPROGRESS) {
789 		retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
790 		if (retval)
791 			dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, retval = %d\n", retval);
792 	}
793 }
794 
795 /*
796  * mos7720_bulk_out_data_callback
797  *	this is the callback function for when we have finished sending serial
798  *	data on the bulk out endpoint.
799  */
800 static void mos7720_bulk_out_data_callback(struct urb *urb)
801 {
802 	struct moschip_port *mos7720_port;
803 	int status = urb->status;
804 
805 	if (status) {
806 		dev_dbg(&urb->dev->dev, "nonzero write bulk status received:%d\n", status);
807 		return;
808 	}
809 
810 	mos7720_port = urb->context;
811 	if (!mos7720_port) {
812 		dev_dbg(&urb->dev->dev, "NULL mos7720_port pointer\n");
813 		return ;
814 	}
815 
816 	if (mos7720_port->open)
817 		tty_port_tty_wakeup(&mos7720_port->port->port);
818 }
819 
820 static int mos77xx_calc_num_ports(struct usb_serial *serial,
821 					struct usb_serial_endpoints *epds)
822 {
823 	u16 product = le16_to_cpu(serial->dev->descriptor.idProduct);
824 
825 	if (product == MOSCHIP_DEVICE_ID_7715) {
826 		/*
827 		 * The 7715 uses the first bulk in/out endpoint pair for the
828 		 * parallel port, and the second for the serial port. We swap
829 		 * the endpoint descriptors here so that the first and
830 		 * only registered port structure uses the serial-port
831 		 * endpoints.
832 		 */
833 		swap(epds->bulk_in[0], epds->bulk_in[1]);
834 		swap(epds->bulk_out[0], epds->bulk_out[1]);
835 
836 		return 1;
837 	}
838 
839 	return 2;
840 }
841 
842 static int mos7720_open(struct tty_struct *tty, struct usb_serial_port *port)
843 {
844 	struct usb_serial *serial;
845 	struct urb *urb;
846 	struct moschip_port *mos7720_port;
847 	int response;
848 	int port_number;
849 	__u8 data;
850 	int allocated_urbs = 0;
851 	int j;
852 
853 	serial = port->serial;
854 
855 	mos7720_port = usb_get_serial_port_data(port);
856 	if (mos7720_port == NULL)
857 		return -ENODEV;
858 
859 	usb_clear_halt(serial->dev, port->write_urb->pipe);
860 	usb_clear_halt(serial->dev, port->read_urb->pipe);
861 
862 	/* Initialising the write urb pool */
863 	for (j = 0; j < NUM_URBS; ++j) {
864 		urb = usb_alloc_urb(0, GFP_KERNEL);
865 		mos7720_port->write_urb_pool[j] = urb;
866 		if (!urb)
867 			continue;
868 
869 		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
870 					       GFP_KERNEL);
871 		if (!urb->transfer_buffer) {
872 			usb_free_urb(mos7720_port->write_urb_pool[j]);
873 			mos7720_port->write_urb_pool[j] = NULL;
874 			continue;
875 		}
876 		allocated_urbs++;
877 	}
878 
879 	if (!allocated_urbs)
880 		return -ENOMEM;
881 
882 	 /* Initialize MCS7720 -- Write Init values to corresponding Registers
883 	  *
884 	  * Register Index
885 	  * 0 : MOS7720_THR/MOS7720_RHR
886 	  * 1 : MOS7720_IER
887 	  * 2 : MOS7720_FCR
888 	  * 3 : MOS7720_LCR
889 	  * 4 : MOS7720_MCR
890 	  * 5 : MOS7720_LSR
891 	  * 6 : MOS7720_MSR
892 	  * 7 : MOS7720_SPR
893 	  *
894 	  * 0x08 : SP1/2 Control Reg
895 	  */
896 	port_number = port->port_number;
897 	read_mos_reg(serial, port_number, MOS7720_LSR, &data);
898 
899 	dev_dbg(&port->dev, "SS::%p LSR:%x\n", mos7720_port, data);
900 
901 	write_mos_reg(serial, dummy, MOS7720_SP1_REG, 0x02);
902 	write_mos_reg(serial, dummy, MOS7720_SP2_REG, 0x02);
903 
904 	write_mos_reg(serial, port_number, MOS7720_IER, 0x00);
905 	write_mos_reg(serial, port_number, MOS7720_FCR, 0x00);
906 
907 	write_mos_reg(serial, port_number, MOS7720_FCR, 0xcf);
908 	mos7720_port->shadowLCR = 0x03;
909 	write_mos_reg(serial, port_number, MOS7720_LCR,
910 		      mos7720_port->shadowLCR);
911 	mos7720_port->shadowMCR = 0x0b;
912 	write_mos_reg(serial, port_number, MOS7720_MCR,
913 		      mos7720_port->shadowMCR);
914 
915 	write_mos_reg(serial, port_number, MOS7720_SP_CONTROL_REG, 0x00);
916 	read_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG, &data);
917 	data = data | (port->port_number + 1);
918 	write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG, data);
919 	mos7720_port->shadowLCR = 0x83;
920 	write_mos_reg(serial, port_number, MOS7720_LCR,
921 		      mos7720_port->shadowLCR);
922 	write_mos_reg(serial, port_number, MOS7720_THR, 0x0c);
923 	write_mos_reg(serial, port_number, MOS7720_IER, 0x00);
924 	mos7720_port->shadowLCR = 0x03;
925 	write_mos_reg(serial, port_number, MOS7720_LCR,
926 		      mos7720_port->shadowLCR);
927 	write_mos_reg(serial, port_number, MOS7720_IER, 0x0c);
928 
929 	response = usb_submit_urb(port->read_urb, GFP_KERNEL);
930 	if (response)
931 		dev_err(&port->dev, "%s - Error %d submitting read urb\n",
932 							__func__, response);
933 
934 	/* initialize our port settings */
935 	mos7720_port->shadowMCR = UART_MCR_OUT2; /* Must set to enable ints! */
936 
937 	/* send a open port command */
938 	mos7720_port->open = 1;
939 
940 	return 0;
941 }
942 
943 /*
944  * mos7720_chars_in_buffer
945  *	this function is called by the tty driver when it wants to know how many
946  *	bytes of data we currently have outstanding in the port (data that has
947  *	been written, but hasn't made it out the port yet)
948  */
949 static unsigned int mos7720_chars_in_buffer(struct tty_struct *tty)
950 {
951 	struct usb_serial_port *port = tty->driver_data;
952 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
953 	int i;
954 	unsigned int chars = 0;
955 
956 	for (i = 0; i < NUM_URBS; ++i) {
957 		if (mos7720_port->write_urb_pool[i] &&
958 		    mos7720_port->write_urb_pool[i]->status == -EINPROGRESS)
959 			chars += URB_TRANSFER_BUFFER_SIZE;
960 	}
961 	dev_dbg(&port->dev, "%s - returns %u\n", __func__, chars);
962 	return chars;
963 }
964 
965 static void mos7720_close(struct usb_serial_port *port)
966 {
967 	struct usb_serial *serial;
968 	struct moschip_port *mos7720_port;
969 	int j;
970 
971 	serial = port->serial;
972 
973 	mos7720_port = usb_get_serial_port_data(port);
974 	if (mos7720_port == NULL)
975 		return;
976 
977 	for (j = 0; j < NUM_URBS; ++j)
978 		usb_kill_urb(mos7720_port->write_urb_pool[j]);
979 
980 	/* Freeing Write URBs */
981 	for (j = 0; j < NUM_URBS; ++j) {
982 		if (mos7720_port->write_urb_pool[j]) {
983 			kfree(mos7720_port->write_urb_pool[j]->transfer_buffer);
984 			usb_free_urb(mos7720_port->write_urb_pool[j]);
985 		}
986 	}
987 
988 	/* While closing port, shutdown all bulk read, write  *
989 	 * and interrupt read if they exists, otherwise nop   */
990 	usb_kill_urb(port->write_urb);
991 	usb_kill_urb(port->read_urb);
992 
993 	write_mos_reg(serial, port->port_number, MOS7720_MCR, 0x00);
994 	write_mos_reg(serial, port->port_number, MOS7720_IER, 0x00);
995 
996 	mos7720_port->open = 0;
997 }
998 
999 static int mos7720_break(struct tty_struct *tty, int break_state)
1000 {
1001 	struct usb_serial_port *port = tty->driver_data;
1002 	unsigned char data;
1003 	struct usb_serial *serial;
1004 	struct moschip_port *mos7720_port;
1005 
1006 	serial = port->serial;
1007 
1008 	mos7720_port = usb_get_serial_port_data(port);
1009 	if (mos7720_port == NULL)
1010 		return -ENODEV;
1011 
1012 	if (break_state == -1)
1013 		data = mos7720_port->shadowLCR | UART_LCR_SBC;
1014 	else
1015 		data = mos7720_port->shadowLCR & ~UART_LCR_SBC;
1016 
1017 	mos7720_port->shadowLCR  = data;
1018 
1019 	return write_mos_reg(serial, port->port_number, MOS7720_LCR,
1020 			     mos7720_port->shadowLCR);
1021 }
1022 
1023 /*
1024  * mos7720_write_room
1025  *	this function is called by the tty driver when it wants to know how many
1026  *	bytes of data we can accept for a specific port.
1027  */
1028 static unsigned int mos7720_write_room(struct tty_struct *tty)
1029 {
1030 	struct usb_serial_port *port = tty->driver_data;
1031 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
1032 	unsigned int room = 0;
1033 	int i;
1034 
1035 	/* FIXME: Locking */
1036 	for (i = 0; i < NUM_URBS; ++i) {
1037 		if (mos7720_port->write_urb_pool[i] &&
1038 		    mos7720_port->write_urb_pool[i]->status != -EINPROGRESS)
1039 			room += URB_TRANSFER_BUFFER_SIZE;
1040 	}
1041 
1042 	dev_dbg(&port->dev, "%s - returns %u\n", __func__, room);
1043 	return room;
1044 }
1045 
1046 static int mos7720_write(struct tty_struct *tty, struct usb_serial_port *port,
1047 				 const unsigned char *data, int count)
1048 {
1049 	int status;
1050 	int i;
1051 	int bytes_sent = 0;
1052 	int transfer_size;
1053 
1054 	struct moschip_port *mos7720_port;
1055 	struct usb_serial *serial;
1056 	struct urb    *urb;
1057 	const unsigned char *current_position = data;
1058 
1059 	serial = port->serial;
1060 
1061 	mos7720_port = usb_get_serial_port_data(port);
1062 	if (mos7720_port == NULL)
1063 		return -ENODEV;
1064 
1065 	/* try to find a free urb in the list */
1066 	urb = NULL;
1067 
1068 	for (i = 0; i < NUM_URBS; ++i) {
1069 		if (mos7720_port->write_urb_pool[i] &&
1070 		    mos7720_port->write_urb_pool[i]->status != -EINPROGRESS) {
1071 			urb = mos7720_port->write_urb_pool[i];
1072 			dev_dbg(&port->dev, "URB:%d\n", i);
1073 			break;
1074 		}
1075 	}
1076 
1077 	if (urb == NULL) {
1078 		dev_dbg(&port->dev, "%s - no more free urbs\n", __func__);
1079 		goto exit;
1080 	}
1081 
1082 	if (urb->transfer_buffer == NULL) {
1083 		urb->transfer_buffer = kmalloc(URB_TRANSFER_BUFFER_SIZE,
1084 					       GFP_ATOMIC);
1085 		if (!urb->transfer_buffer) {
1086 			bytes_sent = -ENOMEM;
1087 			goto exit;
1088 		}
1089 	}
1090 	transfer_size = min(count, URB_TRANSFER_BUFFER_SIZE);
1091 
1092 	memcpy(urb->transfer_buffer, current_position, transfer_size);
1093 	usb_serial_debug_data(&port->dev, __func__, transfer_size,
1094 			      urb->transfer_buffer);
1095 
1096 	/* fill urb with data and submit  */
1097 	usb_fill_bulk_urb(urb, serial->dev,
1098 			  usb_sndbulkpipe(serial->dev,
1099 					port->bulk_out_endpointAddress),
1100 			  urb->transfer_buffer, transfer_size,
1101 			  mos7720_bulk_out_data_callback, mos7720_port);
1102 
1103 	/* send it down the pipe */
1104 	status = usb_submit_urb(urb, GFP_ATOMIC);
1105 	if (status) {
1106 		dev_err_console(port, "%s - usb_submit_urb(write bulk) failed "
1107 			"with status = %d\n", __func__, status);
1108 		bytes_sent = status;
1109 		goto exit;
1110 	}
1111 	bytes_sent = transfer_size;
1112 
1113 exit:
1114 	return bytes_sent;
1115 }
1116 
1117 static void mos7720_throttle(struct tty_struct *tty)
1118 {
1119 	struct usb_serial_port *port = tty->driver_data;
1120 	struct moschip_port *mos7720_port;
1121 	int status;
1122 
1123 	mos7720_port = usb_get_serial_port_data(port);
1124 
1125 	if (mos7720_port == NULL)
1126 		return;
1127 
1128 	if (!mos7720_port->open) {
1129 		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
1130 		return;
1131 	}
1132 
1133 	/* if we are implementing XON/XOFF, send the stop character */
1134 	if (I_IXOFF(tty)) {
1135 		unsigned char stop_char = STOP_CHAR(tty);
1136 		status = mos7720_write(tty, port, &stop_char, 1);
1137 		if (status <= 0)
1138 			return;
1139 	}
1140 
1141 	/* if we are implementing RTS/CTS, toggle that line */
1142 	if (C_CRTSCTS(tty)) {
1143 		mos7720_port->shadowMCR &= ~UART_MCR_RTS;
1144 		write_mos_reg(port->serial, port->port_number, MOS7720_MCR,
1145 			      mos7720_port->shadowMCR);
1146 	}
1147 }
1148 
1149 static void mos7720_unthrottle(struct tty_struct *tty)
1150 {
1151 	struct usb_serial_port *port = tty->driver_data;
1152 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
1153 	int status;
1154 
1155 	if (mos7720_port == NULL)
1156 		return;
1157 
1158 	if (!mos7720_port->open) {
1159 		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
1160 		return;
1161 	}
1162 
1163 	/* if we are implementing XON/XOFF, send the start character */
1164 	if (I_IXOFF(tty)) {
1165 		unsigned char start_char = START_CHAR(tty);
1166 		status = mos7720_write(tty, port, &start_char, 1);
1167 		if (status <= 0)
1168 			return;
1169 	}
1170 
1171 	/* if we are implementing RTS/CTS, toggle that line */
1172 	if (C_CRTSCTS(tty)) {
1173 		mos7720_port->shadowMCR |= UART_MCR_RTS;
1174 		write_mos_reg(port->serial, port->port_number, MOS7720_MCR,
1175 			      mos7720_port->shadowMCR);
1176 	}
1177 }
1178 
1179 /* FIXME: this function does not work */
1180 static int set_higher_rates(struct moschip_port *mos7720_port,
1181 			    unsigned int baud)
1182 {
1183 	struct usb_serial_port *port;
1184 	struct usb_serial *serial;
1185 	int port_number;
1186 	enum mos_regs sp_reg;
1187 	if (mos7720_port == NULL)
1188 		return -EINVAL;
1189 
1190 	port = mos7720_port->port;
1191 	serial = port->serial;
1192 
1193 	 /***********************************************
1194 	 *      Init Sequence for higher rates
1195 	 ***********************************************/
1196 	dev_dbg(&port->dev, "Sending Setting Commands ..........\n");
1197 	port_number = port->port_number;
1198 
1199 	write_mos_reg(serial, port_number, MOS7720_IER, 0x00);
1200 	write_mos_reg(serial, port_number, MOS7720_FCR, 0x00);
1201 	write_mos_reg(serial, port_number, MOS7720_FCR, 0xcf);
1202 	mos7720_port->shadowMCR = 0x0b;
1203 	write_mos_reg(serial, port_number, MOS7720_MCR,
1204 		      mos7720_port->shadowMCR);
1205 	write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG, 0x00);
1206 
1207 	/***********************************************
1208 	 *              Set for higher rates           *
1209 	 ***********************************************/
1210 	/* writing baud rate verbatum into uart clock field clearly not right */
1211 	if (port_number == 0)
1212 		sp_reg = MOS7720_SP1_REG;
1213 	else
1214 		sp_reg = MOS7720_SP2_REG;
1215 	write_mos_reg(serial, dummy, sp_reg, baud * 0x10);
1216 	write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG, 0x03);
1217 	mos7720_port->shadowMCR = 0x2b;
1218 	write_mos_reg(serial, port_number, MOS7720_MCR,
1219 		      mos7720_port->shadowMCR);
1220 
1221 	/***********************************************
1222 	 *              Set DLL/DLM
1223 	 ***********************************************/
1224 	mos7720_port->shadowLCR = mos7720_port->shadowLCR | UART_LCR_DLAB;
1225 	write_mos_reg(serial, port_number, MOS7720_LCR,
1226 		      mos7720_port->shadowLCR);
1227 	write_mos_reg(serial, port_number, MOS7720_DLL, 0x01);
1228 	write_mos_reg(serial, port_number, MOS7720_DLM, 0x00);
1229 	mos7720_port->shadowLCR = mos7720_port->shadowLCR & ~UART_LCR_DLAB;
1230 	write_mos_reg(serial, port_number, MOS7720_LCR,
1231 		      mos7720_port->shadowLCR);
1232 
1233 	return 0;
1234 }
1235 
1236 /* baud rate information */
1237 struct divisor_table_entry {
1238 	__u32  baudrate;
1239 	__u16  divisor;
1240 };
1241 
1242 /* Define table of divisors for moschip 7720 hardware	   *
1243  * These assume a 3.6864MHz crystal, the standard /16, and *
1244  * MCR.7 = 0.						   */
1245 static const struct divisor_table_entry divisor_table[] = {
1246 	{   50,		2304},
1247 	{   110,	1047},	/* 2094.545455 => 230450   => .0217 % over */
1248 	{   134,	857},	/* 1713.011152 => 230398.5 => .00065% under */
1249 	{   150,	768},
1250 	{   300,	384},
1251 	{   600,	192},
1252 	{   1200,	96},
1253 	{   1800,	64},
1254 	{   2400,	48},
1255 	{   4800,	24},
1256 	{   7200,	16},
1257 	{   9600,	12},
1258 	{   19200,	6},
1259 	{   38400,	3},
1260 	{   57600,	2},
1261 	{   115200,	1},
1262 };
1263 
1264 /*****************************************************************************
1265  * calc_baud_rate_divisor
1266  *	this function calculates the proper baud rate divisor for the specified
1267  *	baud rate.
1268  *****************************************************************************/
1269 static int calc_baud_rate_divisor(struct usb_serial_port *port, int baudrate, int *divisor)
1270 {
1271 	int i;
1272 	__u16 custom;
1273 	__u16 round1;
1274 	__u16 round;
1275 
1276 
1277 	dev_dbg(&port->dev, "%s - %d\n", __func__, baudrate);
1278 
1279 	for (i = 0; i < ARRAY_SIZE(divisor_table); i++) {
1280 		if (divisor_table[i].baudrate == baudrate) {
1281 			*divisor = divisor_table[i].divisor;
1282 			return 0;
1283 		}
1284 	}
1285 
1286 	/* After trying for all the standard baud rates    *
1287 	 * Try calculating the divisor for this baud rate  */
1288 	if (baudrate > 75 &&  baudrate < 230400) {
1289 		/* get the divisor */
1290 		custom = (__u16)(230400L  / baudrate);
1291 
1292 		/* Check for round off */
1293 		round1 = (__u16)(2304000L / baudrate);
1294 		round = (__u16)(round1 - (custom * 10));
1295 		if (round > 4)
1296 			custom++;
1297 		*divisor = custom;
1298 
1299 		dev_dbg(&port->dev, "Baud %d = %d\n", baudrate, custom);
1300 		return 0;
1301 	}
1302 
1303 	dev_dbg(&port->dev, "Baud calculation Failed...\n");
1304 	return -EINVAL;
1305 }
1306 
1307 /*
1308  * send_cmd_write_baud_rate
1309  *	this function sends the proper command to change the baud rate of the
1310  *	specified port.
1311  */
1312 static int send_cmd_write_baud_rate(struct moschip_port *mos7720_port,
1313 				    int baudrate)
1314 {
1315 	struct usb_serial_port *port;
1316 	struct usb_serial *serial;
1317 	int divisor;
1318 	int status;
1319 	unsigned char number;
1320 
1321 	if (mos7720_port == NULL)
1322 		return -1;
1323 
1324 	port = mos7720_port->port;
1325 	serial = port->serial;
1326 
1327 	number = port->port_number;
1328 	dev_dbg(&port->dev, "%s - baud = %d\n", __func__, baudrate);
1329 
1330 	/* Calculate the Divisor */
1331 	status = calc_baud_rate_divisor(port, baudrate, &divisor);
1332 	if (status) {
1333 		dev_err(&port->dev, "%s - bad baud rate\n", __func__);
1334 		return status;
1335 	}
1336 
1337 	/* Enable access to divisor latch */
1338 	mos7720_port->shadowLCR = mos7720_port->shadowLCR | UART_LCR_DLAB;
1339 	write_mos_reg(serial, number, MOS7720_LCR, mos7720_port->shadowLCR);
1340 
1341 	/* Write the divisor */
1342 	write_mos_reg(serial, number, MOS7720_DLL, (__u8)(divisor & 0xff));
1343 	write_mos_reg(serial, number, MOS7720_DLM,
1344 		      (__u8)((divisor & 0xff00) >> 8));
1345 
1346 	/* Disable access to divisor latch */
1347 	mos7720_port->shadowLCR = mos7720_port->shadowLCR & ~UART_LCR_DLAB;
1348 	write_mos_reg(serial, number, MOS7720_LCR, mos7720_port->shadowLCR);
1349 
1350 	return status;
1351 }
1352 
1353 /*
1354  * change_port_settings
1355  *	This routine is called to set the UART on the device to match
1356  *      the specified new settings.
1357  */
1358 static void change_port_settings(struct tty_struct *tty,
1359 				 struct moschip_port *mos7720_port,
1360 				 const struct ktermios *old_termios)
1361 {
1362 	struct usb_serial_port *port;
1363 	struct usb_serial *serial;
1364 	int baud;
1365 	unsigned cflag;
1366 	__u8 lData;
1367 	__u8 lParity;
1368 	__u8 lStop;
1369 	int status;
1370 	int port_number;
1371 
1372 	if (mos7720_port == NULL)
1373 		return ;
1374 
1375 	port = mos7720_port->port;
1376 	serial = port->serial;
1377 	port_number = port->port_number;
1378 
1379 	if (!mos7720_port->open) {
1380 		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
1381 		return;
1382 	}
1383 
1384 	lStop = 0x00;	/* 1 stop bit */
1385 	lParity = 0x00;	/* No parity */
1386 
1387 	cflag = tty->termios.c_cflag;
1388 
1389 	lData = UART_LCR_WLEN(tty_get_char_size(cflag));
1390 
1391 	/* Change the Parity bit */
1392 	if (cflag & PARENB) {
1393 		if (cflag & PARODD) {
1394 			lParity = UART_LCR_PARITY;
1395 			dev_dbg(&port->dev, "%s - parity = odd\n", __func__);
1396 		} else {
1397 			lParity = (UART_LCR_EPAR | UART_LCR_PARITY);
1398 			dev_dbg(&port->dev, "%s - parity = even\n", __func__);
1399 		}
1400 
1401 	} else {
1402 		dev_dbg(&port->dev, "%s - parity = none\n", __func__);
1403 	}
1404 
1405 	if (cflag & CMSPAR)
1406 		lParity = lParity | 0x20;
1407 
1408 	/* Change the Stop bit */
1409 	if (cflag & CSTOPB) {
1410 		lStop = UART_LCR_STOP;
1411 		dev_dbg(&port->dev, "%s - stop bits = 2\n", __func__);
1412 	} else {
1413 		lStop = 0x00;
1414 		dev_dbg(&port->dev, "%s - stop bits = 1\n", __func__);
1415 	}
1416 
1417 #define LCR_BITS_MASK		0x03	/* Mask for bits/char field */
1418 #define LCR_STOP_MASK		0x04	/* Mask for stop bits field */
1419 #define LCR_PAR_MASK		0x38	/* Mask for parity field */
1420 
1421 	/* Update the LCR with the correct value */
1422 	mos7720_port->shadowLCR &=
1423 		~(LCR_BITS_MASK | LCR_STOP_MASK | LCR_PAR_MASK);
1424 	mos7720_port->shadowLCR |= (lData | lParity | lStop);
1425 
1426 
1427 	/* Disable Interrupts */
1428 	write_mos_reg(serial, port_number, MOS7720_IER, 0x00);
1429 	write_mos_reg(serial, port_number, MOS7720_FCR, 0x00);
1430 	write_mos_reg(serial, port_number, MOS7720_FCR, 0xcf);
1431 
1432 	/* Send the updated LCR value to the mos7720 */
1433 	write_mos_reg(serial, port_number, MOS7720_LCR,
1434 		      mos7720_port->shadowLCR);
1435 	mos7720_port->shadowMCR = 0x0b;
1436 	write_mos_reg(serial, port_number, MOS7720_MCR,
1437 		      mos7720_port->shadowMCR);
1438 
1439 	/* set up the MCR register and send it to the mos7720 */
1440 	mos7720_port->shadowMCR = UART_MCR_OUT2;
1441 	if (cflag & CBAUD)
1442 		mos7720_port->shadowMCR |= (UART_MCR_DTR | UART_MCR_RTS);
1443 
1444 	if (cflag & CRTSCTS) {
1445 		mos7720_port->shadowMCR |= (UART_MCR_XONANY);
1446 		/* To set hardware flow control to the specified *
1447 		 * serial port, in SP1/2_CONTROL_REG             */
1448 		if (port_number)
1449 			write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG,
1450 				      0x01);
1451 		else
1452 			write_mos_reg(serial, dummy, MOS7720_SP_CONTROL_REG,
1453 				      0x02);
1454 
1455 	} else
1456 		mos7720_port->shadowMCR &= ~(UART_MCR_XONANY);
1457 
1458 	write_mos_reg(serial, port_number, MOS7720_MCR,
1459 		      mos7720_port->shadowMCR);
1460 
1461 	/* Determine divisor based on baud rate */
1462 	baud = tty_get_baud_rate(tty);
1463 	if (!baud) {
1464 		/* pick a default, any default... */
1465 		dev_dbg(&port->dev, "Picked default baud...\n");
1466 		baud = 9600;
1467 	}
1468 
1469 	if (baud >= 230400) {
1470 		set_higher_rates(mos7720_port, baud);
1471 		/* Enable Interrupts */
1472 		write_mos_reg(serial, port_number, MOS7720_IER, 0x0c);
1473 		return;
1474 	}
1475 
1476 	dev_dbg(&port->dev, "%s - baud rate = %d\n", __func__, baud);
1477 	status = send_cmd_write_baud_rate(mos7720_port, baud);
1478 	/* FIXME: needs to write actual resulting baud back not just
1479 	   blindly do so */
1480 	if (cflag & CBAUD)
1481 		tty_encode_baud_rate(tty, baud, baud);
1482 	/* Enable Interrupts */
1483 	write_mos_reg(serial, port_number, MOS7720_IER, 0x0c);
1484 
1485 	if (port->read_urb->status != -EINPROGRESS) {
1486 		status = usb_submit_urb(port->read_urb, GFP_KERNEL);
1487 		if (status)
1488 			dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, status = %d\n", status);
1489 	}
1490 }
1491 
1492 /*
1493  * mos7720_set_termios
1494  *	this function is called by the tty driver when it wants to change the
1495  *	termios structure.
1496  */
1497 static void mos7720_set_termios(struct tty_struct *tty,
1498 				struct usb_serial_port *port,
1499 				const struct ktermios *old_termios)
1500 {
1501 	int status;
1502 	struct moschip_port *mos7720_port;
1503 
1504 	mos7720_port = usb_get_serial_port_data(port);
1505 
1506 	if (mos7720_port == NULL)
1507 		return;
1508 
1509 	if (!mos7720_port->open) {
1510 		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
1511 		return;
1512 	}
1513 
1514 	/* change the port settings to the new ones specified */
1515 	change_port_settings(tty, mos7720_port, old_termios);
1516 
1517 	if (port->read_urb->status != -EINPROGRESS) {
1518 		status = usb_submit_urb(port->read_urb, GFP_KERNEL);
1519 		if (status)
1520 			dev_dbg(&port->dev, "usb_submit_urb(read bulk) failed, status = %d\n", status);
1521 	}
1522 }
1523 
1524 /*
1525  * get_lsr_info - get line status register info
1526  *
1527  * Purpose: Let user call ioctl() to get info when the UART physically
1528  * 	    is emptied.  On bus types like RS485, the transmitter must
1529  * 	    release the bus after transmitting. This must be done when
1530  * 	    the transmit shift register is empty, not be done when the
1531  * 	    transmit holding register is empty.  This functionality
1532  * 	    allows an RS485 driver to be written in user space.
1533  */
1534 static int get_lsr_info(struct tty_struct *tty,
1535 		struct moschip_port *mos7720_port, unsigned int __user *value)
1536 {
1537 	struct usb_serial_port *port = tty->driver_data;
1538 	unsigned int result = 0;
1539 	unsigned char data = 0;
1540 	int port_number = port->port_number;
1541 	int count;
1542 
1543 	count = mos7720_chars_in_buffer(tty);
1544 	if (count == 0) {
1545 		read_mos_reg(port->serial, port_number, MOS7720_LSR, &data);
1546 		if ((data & (UART_LSR_TEMT | UART_LSR_THRE))
1547 					== (UART_LSR_TEMT | UART_LSR_THRE)) {
1548 			dev_dbg(&port->dev, "%s -- Empty\n", __func__);
1549 			result = TIOCSER_TEMT;
1550 		}
1551 	}
1552 	if (copy_to_user(value, &result, sizeof(int)))
1553 		return -EFAULT;
1554 	return 0;
1555 }
1556 
1557 static int mos7720_tiocmget(struct tty_struct *tty)
1558 {
1559 	struct usb_serial_port *port = tty->driver_data;
1560 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
1561 	unsigned int result = 0;
1562 	unsigned int mcr ;
1563 	unsigned int msr ;
1564 
1565 	mcr = mos7720_port->shadowMCR;
1566 	msr = mos7720_port->shadowMSR;
1567 
1568 	result = ((mcr & UART_MCR_DTR)  ? TIOCM_DTR : 0)   /* 0x002 */
1569 	  | ((mcr & UART_MCR_RTS)   ? TIOCM_RTS : 0)   /* 0x004 */
1570 	  | ((msr & UART_MSR_CTS)   ? TIOCM_CTS : 0)   /* 0x020 */
1571 	  | ((msr & UART_MSR_DCD)   ? TIOCM_CAR : 0)   /* 0x040 */
1572 	  | ((msr & UART_MSR_RI)    ? TIOCM_RI :  0)   /* 0x080 */
1573 	  | ((msr & UART_MSR_DSR)   ? TIOCM_DSR : 0);  /* 0x100 */
1574 
1575 	return result;
1576 }
1577 
1578 static int mos7720_tiocmset(struct tty_struct *tty,
1579 			    unsigned int set, unsigned int clear)
1580 {
1581 	struct usb_serial_port *port = tty->driver_data;
1582 	struct moschip_port *mos7720_port = usb_get_serial_port_data(port);
1583 	unsigned int mcr ;
1584 
1585 	mcr = mos7720_port->shadowMCR;
1586 
1587 	if (set & TIOCM_RTS)
1588 		mcr |= UART_MCR_RTS;
1589 	if (set & TIOCM_DTR)
1590 		mcr |= UART_MCR_DTR;
1591 	if (set & TIOCM_LOOP)
1592 		mcr |= UART_MCR_LOOP;
1593 
1594 	if (clear & TIOCM_RTS)
1595 		mcr &= ~UART_MCR_RTS;
1596 	if (clear & TIOCM_DTR)
1597 		mcr &= ~UART_MCR_DTR;
1598 	if (clear & TIOCM_LOOP)
1599 		mcr &= ~UART_MCR_LOOP;
1600 
1601 	mos7720_port->shadowMCR = mcr;
1602 	write_mos_reg(port->serial, port->port_number, MOS7720_MCR,
1603 		      mos7720_port->shadowMCR);
1604 
1605 	return 0;
1606 }
1607 
1608 static int mos7720_ioctl(struct tty_struct *tty,
1609 			 unsigned int cmd, unsigned long arg)
1610 {
1611 	struct usb_serial_port *port = tty->driver_data;
1612 	struct moschip_port *mos7720_port;
1613 
1614 	mos7720_port = usb_get_serial_port_data(port);
1615 	if (mos7720_port == NULL)
1616 		return -ENODEV;
1617 
1618 	switch (cmd) {
1619 	case TIOCSERGETLSR:
1620 		dev_dbg(&port->dev, "%s TIOCSERGETLSR\n", __func__);
1621 		return get_lsr_info(tty, mos7720_port,
1622 					(unsigned int __user *)arg);
1623 	}
1624 
1625 	return -ENOIOCTLCMD;
1626 }
1627 
1628 static int mos7720_startup(struct usb_serial *serial)
1629 {
1630 	struct usb_device *dev;
1631 	char data;
1632 	u16 product;
1633 	int ret_val;
1634 
1635 	product = le16_to_cpu(serial->dev->descriptor.idProduct);
1636 	dev = serial->dev;
1637 
1638 	if (product == MOSCHIP_DEVICE_ID_7715) {
1639 		struct urb *urb = serial->port[0]->interrupt_in_urb;
1640 
1641 		urb->complete = mos7715_interrupt_callback;
1642 
1643 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
1644 		ret_val = mos7715_parport_init(serial);
1645 		if (ret_val < 0)
1646 			return ret_val;
1647 #endif
1648 	}
1649 	/* start the interrupt urb */
1650 	ret_val = usb_submit_urb(serial->port[0]->interrupt_in_urb, GFP_KERNEL);
1651 	if (ret_val) {
1652 		dev_err(&dev->dev, "failed to submit interrupt urb: %d\n",
1653 			ret_val);
1654 	}
1655 
1656 	/* LSR For Port 1 */
1657 	read_mos_reg(serial, 0, MOS7720_LSR, &data);
1658 	dev_dbg(&dev->dev, "LSR:%x\n", data);
1659 
1660 	return 0;
1661 }
1662 
1663 static void mos7720_release(struct usb_serial *serial)
1664 {
1665 	usb_kill_urb(serial->port[0]->interrupt_in_urb);
1666 
1667 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
1668 	/* close the parallel port */
1669 
1670 	if (le16_to_cpu(serial->dev->descriptor.idProduct)
1671 	    == MOSCHIP_DEVICE_ID_7715) {
1672 		struct mos7715_parport *mos_parport =
1673 			usb_get_serial_data(serial);
1674 
1675 		/* prevent NULL ptr dereference in port callbacks */
1676 		spin_lock(&release_lock);
1677 		mos_parport->pp->private_data = NULL;
1678 		spin_unlock(&release_lock);
1679 
1680 		/* wait for synchronous usb calls to return */
1681 		if (mos_parport->msg_pending)
1682 			wait_for_completion_timeout(&mos_parport->syncmsg_compl,
1683 					    msecs_to_jiffies(MOS_WDR_TIMEOUT));
1684 		/*
1685 		 * If delayed work is currently scheduled, wait for it to
1686 		 * complete. This also implies barriers that ensure the
1687 		 * below serial clearing is not hoisted above the ->work.
1688 		 */
1689 		cancel_work_sync(&mos_parport->work);
1690 
1691 		parport_remove_port(mos_parport->pp);
1692 		usb_set_serial_data(serial, NULL);
1693 		mos_parport->serial = NULL;
1694 
1695 		parport_del_port(mos_parport->pp);
1696 
1697 		kref_put(&mos_parport->ref_count, destroy_mos_parport);
1698 	}
1699 #endif
1700 }
1701 
1702 static int mos7720_port_probe(struct usb_serial_port *port)
1703 {
1704 	struct moschip_port *mos7720_port;
1705 
1706 	mos7720_port = kzalloc(sizeof(*mos7720_port), GFP_KERNEL);
1707 	if (!mos7720_port)
1708 		return -ENOMEM;
1709 
1710 	mos7720_port->port = port;
1711 
1712 	usb_set_serial_port_data(port, mos7720_port);
1713 
1714 	return 0;
1715 }
1716 
1717 static void mos7720_port_remove(struct usb_serial_port *port)
1718 {
1719 	struct moschip_port *mos7720_port;
1720 
1721 	mos7720_port = usb_get_serial_port_data(port);
1722 	kfree(mos7720_port);
1723 }
1724 
1725 static struct usb_serial_driver moschip7720_2port_driver = {
1726 	.driver = {
1727 		.owner =	THIS_MODULE,
1728 		.name =		"moschip7720",
1729 	},
1730 	.description		= "Moschip 2 port adapter",
1731 	.id_table		= id_table,
1732 	.num_bulk_in		= 2,
1733 	.num_bulk_out		= 2,
1734 	.num_interrupt_in	= 1,
1735 	.calc_num_ports		= mos77xx_calc_num_ports,
1736 	.open			= mos7720_open,
1737 	.close			= mos7720_close,
1738 	.throttle		= mos7720_throttle,
1739 	.unthrottle		= mos7720_unthrottle,
1740 	.attach			= mos7720_startup,
1741 	.release		= mos7720_release,
1742 	.port_probe		= mos7720_port_probe,
1743 	.port_remove		= mos7720_port_remove,
1744 	.ioctl			= mos7720_ioctl,
1745 	.tiocmget		= mos7720_tiocmget,
1746 	.tiocmset		= mos7720_tiocmset,
1747 	.set_termios		= mos7720_set_termios,
1748 	.write			= mos7720_write,
1749 	.write_room		= mos7720_write_room,
1750 	.chars_in_buffer	= mos7720_chars_in_buffer,
1751 	.break_ctl		= mos7720_break,
1752 	.read_bulk_callback	= mos7720_bulk_in_callback,
1753 	.read_int_callback	= mos7720_interrupt_callback,
1754 };
1755 
1756 static struct usb_serial_driver * const serial_drivers[] = {
1757 	&moschip7720_2port_driver, NULL
1758 };
1759 
1760 module_usb_serial_driver(serial_drivers, id_table);
1761 
1762 MODULE_AUTHOR(DRIVER_AUTHOR);
1763 MODULE_DESCRIPTION(DRIVER_DESC);
1764 MODULE_LICENSE("GPL v2");
1765