xref: /linux/drivers/usb/serial/cypress_m8.c (revision 95e9fd10f06cb5642028b6b851e32b8c8afb4571)
1 /*
2  * USB Cypress M8 driver
3  *
4  * 	Copyright (C) 2004
5  * 	    Lonnie Mendez (dignome@gmail.com)
6  *	Copyright (C) 2003,2004
7  *	    Neil Whelchel (koyama@firstlight.net)
8  *
9  * 	This program is free software; you can redistribute it and/or modify
10  * 	it under the terms of the GNU General Public License as published by
11  * 	the Free Software Foundation; either version 2 of the License, or
12  * 	(at your option) any later version.
13  *
14  * See Documentation/usb/usb-serial.txt for more information on using this
15  * driver
16  *
17  * See http://geocities.com/i0xox0i for information on this driver and the
18  * earthmate usb device.
19  */
20 
21 /* Thanks to Neil Whelchel for writing the first cypress m8 implementation
22    for linux. */
23 /* Thanks to cypress for providing references for the hid reports. */
24 /* Thanks to Jiang Zhang for providing links and for general help. */
25 /* Code originates and was built up from ftdi_sio, belkin, pl2303 and others.*/
26 
27 
28 #include <linux/kernel.h>
29 #include <linux/errno.h>
30 #include <linux/init.h>
31 #include <linux/slab.h>
32 #include <linux/tty.h>
33 #include <linux/tty_driver.h>
34 #include <linux/tty_flip.h>
35 #include <linux/module.h>
36 #include <linux/moduleparam.h>
37 #include <linux/spinlock.h>
38 #include <linux/usb.h>
39 #include <linux/usb/serial.h>
40 #include <linux/serial.h>
41 #include <linux/kfifo.h>
42 #include <linux/delay.h>
43 #include <linux/uaccess.h>
44 #include <asm/unaligned.h>
45 
46 #include "cypress_m8.h"
47 
48 
49 static bool debug;
50 static bool stats;
51 static int interval;
52 static bool unstable_bauds;
53 
54 /*
55  * Version Information
56  */
57 #define DRIVER_VERSION "v1.10"
58 #define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
59 #define DRIVER_DESC "Cypress USB to Serial Driver"
60 
61 /* write buffer size defines */
62 #define CYPRESS_BUF_SIZE	1024
63 
64 static const struct usb_device_id id_table_earthmate[] = {
65 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
66 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
67 	{ }						/* Terminating entry */
68 };
69 
70 static const struct usb_device_id id_table_cyphidcomrs232[] = {
71 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
72 	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
73 	{ }						/* Terminating entry */
74 };
75 
76 static const struct usb_device_id id_table_nokiaca42v2[] = {
77 	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
78 	{ }						/* Terminating entry */
79 };
80 
81 static const struct usb_device_id id_table_combined[] = {
82 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
83 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
84 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
85 	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
86 	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
87 	{ }						/* Terminating entry */
88 };
89 
90 MODULE_DEVICE_TABLE(usb, id_table_combined);
91 
92 enum packet_format {
93 	packet_format_1,  /* b0:status, b1:payload count */
94 	packet_format_2   /* b0[7:3]:status, b0[2:0]:payload count */
95 };
96 
97 struct cypress_private {
98 	spinlock_t lock;		   /* private lock */
99 	int chiptype;			   /* identifier of device, for quirks/etc */
100 	int bytes_in;			   /* used for statistics */
101 	int bytes_out;			   /* used for statistics */
102 	int cmd_count;			   /* used for statistics */
103 	int cmd_ctrl;			   /* always set this to 1 before issuing a command */
104 	struct kfifo write_fifo;	   /* write fifo */
105 	int write_urb_in_use;		   /* write urb in use indicator */
106 	int write_urb_interval;            /* interval to use for write urb */
107 	int read_urb_interval;             /* interval to use for read urb */
108 	int comm_is_ok;                    /* true if communication is (still) ok */
109 	int termios_initialized;
110 	__u8 line_control;	   	   /* holds dtr / rts value */
111 	__u8 current_status;	   	   /* received from last read - info on dsr,cts,cd,ri,etc */
112 	__u8 current_config;	   	   /* stores the current configuration byte */
113 	__u8 rx_flags;			   /* throttling - used from whiteheat/ftdi_sio */
114 	enum packet_format pkt_fmt;	   /* format to use for packet send / receive */
115 	int get_cfg_unsafe;		   /* If true, the CYPRESS_GET_CONFIG is unsafe */
116 	int baud_rate;			   /* stores current baud rate in
117 					      integer form */
118 	int isthrottled;		   /* if throttled, discard reads */
119 	wait_queue_head_t delta_msr_wait;  /* used for TIOCMIWAIT */
120 	char prev_status, diff_status;	   /* used for TIOCMIWAIT */
121 	/* we pass a pointer to this as the argument sent to
122 	   cypress_set_termios old_termios */
123 	struct ktermios tmp_termios; 	   /* stores the old termios settings */
124 };
125 
126 /* function prototypes for the Cypress USB to serial device */
127 static int  cypress_earthmate_startup(struct usb_serial *serial);
128 static int  cypress_hidcom_startup(struct usb_serial *serial);
129 static int  cypress_ca42v2_startup(struct usb_serial *serial);
130 static void cypress_release(struct usb_serial *serial);
131 static int  cypress_open(struct tty_struct *tty, struct usb_serial_port *port);
132 static void cypress_close(struct usb_serial_port *port);
133 static void cypress_dtr_rts(struct usb_serial_port *port, int on);
134 static int  cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
135 			const unsigned char *buf, int count);
136 static void cypress_send(struct usb_serial_port *port);
137 static int  cypress_write_room(struct tty_struct *tty);
138 static int  cypress_ioctl(struct tty_struct *tty,
139 			unsigned int cmd, unsigned long arg);
140 static void cypress_set_termios(struct tty_struct *tty,
141 			struct usb_serial_port *port, struct ktermios *old);
142 static int  cypress_tiocmget(struct tty_struct *tty);
143 static int  cypress_tiocmset(struct tty_struct *tty,
144 			unsigned int set, unsigned int clear);
145 static int  cypress_chars_in_buffer(struct tty_struct *tty);
146 static void cypress_throttle(struct tty_struct *tty);
147 static void cypress_unthrottle(struct tty_struct *tty);
148 static void cypress_set_dead(struct usb_serial_port *port);
149 static void cypress_read_int_callback(struct urb *urb);
150 static void cypress_write_int_callback(struct urb *urb);
151 
152 static struct usb_serial_driver cypress_earthmate_device = {
153 	.driver = {
154 		.owner =		THIS_MODULE,
155 		.name =			"earthmate",
156 	},
157 	.description =			"DeLorme Earthmate USB",
158 	.id_table =			id_table_earthmate,
159 	.num_ports =			1,
160 	.attach =			cypress_earthmate_startup,
161 	.release =			cypress_release,
162 	.open =				cypress_open,
163 	.close =			cypress_close,
164 	.dtr_rts =			cypress_dtr_rts,
165 	.write =			cypress_write,
166 	.write_room =			cypress_write_room,
167 	.ioctl =			cypress_ioctl,
168 	.set_termios =			cypress_set_termios,
169 	.tiocmget =			cypress_tiocmget,
170 	.tiocmset =			cypress_tiocmset,
171 	.chars_in_buffer =		cypress_chars_in_buffer,
172 	.throttle =		 	cypress_throttle,
173 	.unthrottle =			cypress_unthrottle,
174 	.read_int_callback =		cypress_read_int_callback,
175 	.write_int_callback =		cypress_write_int_callback,
176 };
177 
178 static struct usb_serial_driver cypress_hidcom_device = {
179 	.driver = {
180 		.owner =		THIS_MODULE,
181 		.name =			"cyphidcom",
182 	},
183 	.description =			"HID->COM RS232 Adapter",
184 	.id_table =			id_table_cyphidcomrs232,
185 	.num_ports =			1,
186 	.attach =			cypress_hidcom_startup,
187 	.release =			cypress_release,
188 	.open =				cypress_open,
189 	.close =			cypress_close,
190 	.dtr_rts =			cypress_dtr_rts,
191 	.write =			cypress_write,
192 	.write_room =			cypress_write_room,
193 	.ioctl =			cypress_ioctl,
194 	.set_termios =			cypress_set_termios,
195 	.tiocmget =			cypress_tiocmget,
196 	.tiocmset =			cypress_tiocmset,
197 	.chars_in_buffer =		cypress_chars_in_buffer,
198 	.throttle =			cypress_throttle,
199 	.unthrottle =			cypress_unthrottle,
200 	.read_int_callback =		cypress_read_int_callback,
201 	.write_int_callback =		cypress_write_int_callback,
202 };
203 
204 static struct usb_serial_driver cypress_ca42v2_device = {
205 	.driver = {
206 		.owner =		THIS_MODULE,
207 		.name =			"nokiaca42v2",
208 	},
209 	.description =			"Nokia CA-42 V2 Adapter",
210 	.id_table =			id_table_nokiaca42v2,
211 	.num_ports =			1,
212 	.attach =			cypress_ca42v2_startup,
213 	.release =			cypress_release,
214 	.open =				cypress_open,
215 	.close =			cypress_close,
216 	.dtr_rts =			cypress_dtr_rts,
217 	.write =			cypress_write,
218 	.write_room =			cypress_write_room,
219 	.ioctl =			cypress_ioctl,
220 	.set_termios =			cypress_set_termios,
221 	.tiocmget =			cypress_tiocmget,
222 	.tiocmset =			cypress_tiocmset,
223 	.chars_in_buffer =		cypress_chars_in_buffer,
224 	.throttle =			cypress_throttle,
225 	.unthrottle =			cypress_unthrottle,
226 	.read_int_callback =		cypress_read_int_callback,
227 	.write_int_callback =		cypress_write_int_callback,
228 };
229 
230 static struct usb_serial_driver * const serial_drivers[] = {
231 	&cypress_earthmate_device, &cypress_hidcom_device,
232 	&cypress_ca42v2_device, NULL
233 };
234 
235 /*****************************************************************************
236  * Cypress serial helper functions
237  *****************************************************************************/
238 
239 
240 static int analyze_baud_rate(struct usb_serial_port *port, speed_t new_rate)
241 {
242 	struct cypress_private *priv;
243 	priv = usb_get_serial_port_data(port);
244 
245 	if (unstable_bauds)
246 		return new_rate;
247 
248 	/*
249 	 * The general purpose firmware for the Cypress M8 allows for
250 	 * a maximum speed of 57600bps (I have no idea whether DeLorme
251 	 * chose to use the general purpose firmware or not), if you
252 	 * need to modify this speed setting for your own project
253 	 * please add your own chiptype and modify the code likewise.
254 	 * The Cypress HID->COM device will work successfully up to
255 	 * 115200bps (but the actual throughput is around 3kBps).
256 	 */
257 	if (port->serial->dev->speed == USB_SPEED_LOW) {
258 		/*
259 		 * Mike Isely <isely@pobox.com> 2-Feb-2008: The
260 		 * Cypress app note that describes this mechanism
261 		 * states the the low-speed part can't handle more
262 		 * than 800 bytes/sec, in which case 4800 baud is the
263 		 * safest speed for a part like that.
264 		 */
265 		if (new_rate > 4800) {
266 			dbg("%s - failed setting baud rate, device incapable "
267 			    "speed %d", __func__, new_rate);
268 			return -1;
269 		}
270 	}
271 	switch (priv->chiptype) {
272 	case CT_EARTHMATE:
273 		if (new_rate <= 600) {
274 			/* 300 and 600 baud rates are supported under
275 			 * the generic firmware, but are not used with
276 			 * NMEA and SiRF protocols */
277 			dbg("%s - failed setting baud rate, unsupported speed "
278 			    "of %d on Earthmate GPS", __func__, new_rate);
279 			return -1;
280 		}
281 		break;
282 	default:
283 		break;
284 	}
285 	return new_rate;
286 }
287 
288 
289 /* This function can either set or retrieve the current serial line settings */
290 static int cypress_serial_control(struct tty_struct *tty,
291 	struct usb_serial_port *port, speed_t baud_rate, int data_bits,
292 	int stop_bits, int parity_enable, int parity_type, int reset,
293 	int cypress_request_type)
294 {
295 	int new_baudrate = 0, retval = 0, tries = 0;
296 	struct cypress_private *priv;
297 	u8 *feature_buffer;
298 	const unsigned int feature_len = 5;
299 	unsigned long flags;
300 
301 	priv = usb_get_serial_port_data(port);
302 
303 	if (!priv->comm_is_ok)
304 		return -ENODEV;
305 
306 	feature_buffer = kcalloc(feature_len, sizeof(u8), GFP_KERNEL);
307 	if (!feature_buffer)
308 		return -ENOMEM;
309 
310 	switch (cypress_request_type) {
311 	case CYPRESS_SET_CONFIG:
312 		/* 0 means 'Hang up' so doesn't change the true bit rate */
313 		new_baudrate = priv->baud_rate;
314 		if (baud_rate && baud_rate != priv->baud_rate) {
315 			dbg("%s - baud rate is changing", __func__);
316 			retval = analyze_baud_rate(port, baud_rate);
317 			if (retval >= 0) {
318 				new_baudrate = retval;
319 				dbg("%s - New baud rate set to %d",
320 				    __func__, new_baudrate);
321 			}
322 		}
323 		dbg("%s - baud rate is being sent as %d",
324 					__func__, new_baudrate);
325 
326 		/* fill the feature_buffer with new configuration */
327 		put_unaligned_le32(new_baudrate, feature_buffer);
328 		feature_buffer[4] |= data_bits;   /* assign data bits in 2 bit space ( max 3 ) */
329 		/* 1 bit gap */
330 		feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
331 		feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
332 		feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
333 		/* 1 bit gap */
334 		feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
335 
336 		dbg("%s - device is being sent this feature report:",
337 								__func__);
338 		dbg("%s - %02X - %02X - %02X - %02X - %02X", __func__,
339 			feature_buffer[0], feature_buffer[1],
340 			feature_buffer[2], feature_buffer[3],
341 			feature_buffer[4]);
342 
343 		do {
344 			retval = usb_control_msg(port->serial->dev,
345 					usb_sndctrlpipe(port->serial->dev, 0),
346 					HID_REQ_SET_REPORT,
347 					USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
348 					0x0300, 0, feature_buffer,
349 					feature_len, 500);
350 
351 			if (tries++ >= 3)
352 				break;
353 
354 		} while (retval != feature_len &&
355 			 retval != -ENODEV);
356 
357 		if (retval != feature_len) {
358 			dev_err(&port->dev, "%s - failed sending serial "
359 				"line settings - %d\n", __func__, retval);
360 			cypress_set_dead(port);
361 		} else {
362 			spin_lock_irqsave(&priv->lock, flags);
363 			priv->baud_rate = new_baudrate;
364 			priv->current_config = feature_buffer[4];
365 			spin_unlock_irqrestore(&priv->lock, flags);
366 			/* If we asked for a speed change encode it */
367 			if (baud_rate)
368 				tty_encode_baud_rate(tty,
369 					new_baudrate, new_baudrate);
370 		}
371 	break;
372 	case CYPRESS_GET_CONFIG:
373 		if (priv->get_cfg_unsafe) {
374 			/* Not implemented for this device,
375 			   and if we try to do it we're likely
376 			   to crash the hardware. */
377 			retval = -ENOTTY;
378 			goto out;
379 		}
380 		dbg("%s - retreiving serial line settings", __func__);
381 		do {
382 			retval = usb_control_msg(port->serial->dev,
383 					usb_rcvctrlpipe(port->serial->dev, 0),
384 					HID_REQ_GET_REPORT,
385 					USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
386 					0x0300, 0, feature_buffer,
387 					feature_len, 500);
388 
389 			if (tries++ >= 3)
390 				break;
391 		} while (retval != feature_len
392 						&& retval != -ENODEV);
393 
394 		if (retval != feature_len) {
395 			dev_err(&port->dev, "%s - failed to retrieve serial "
396 				"line settings - %d\n", __func__, retval);
397 			cypress_set_dead(port);
398 			goto out;
399 		} else {
400 			spin_lock_irqsave(&priv->lock, flags);
401 			/* store the config in one byte, and later
402 			   use bit masks to check values */
403 			priv->current_config = feature_buffer[4];
404 			priv->baud_rate = get_unaligned_le32(feature_buffer);
405 			spin_unlock_irqrestore(&priv->lock, flags);
406 		}
407 	}
408 	spin_lock_irqsave(&priv->lock, flags);
409 	++priv->cmd_count;
410 	spin_unlock_irqrestore(&priv->lock, flags);
411 out:
412 	kfree(feature_buffer);
413 	return retval;
414 } /* cypress_serial_control */
415 
416 
417 static void cypress_set_dead(struct usb_serial_port *port)
418 {
419 	struct cypress_private *priv = usb_get_serial_port_data(port);
420 	unsigned long flags;
421 
422 	spin_lock_irqsave(&priv->lock, flags);
423 	if (!priv->comm_is_ok) {
424 		spin_unlock_irqrestore(&priv->lock, flags);
425 		return;
426 	}
427 	priv->comm_is_ok = 0;
428 	spin_unlock_irqrestore(&priv->lock, flags);
429 
430 	dev_err(&port->dev, "cypress_m8 suspending failing port %d - "
431 		"interval might be too short\n", port->number);
432 }
433 
434 
435 /*****************************************************************************
436  * Cypress serial driver functions
437  *****************************************************************************/
438 
439 
440 static int generic_startup(struct usb_serial *serial)
441 {
442 	struct cypress_private *priv;
443 	struct usb_serial_port *port = serial->port[0];
444 
445 	priv = kzalloc(sizeof(struct cypress_private), GFP_KERNEL);
446 	if (!priv)
447 		return -ENOMEM;
448 
449 	priv->comm_is_ok = !0;
450 	spin_lock_init(&priv->lock);
451 	if (kfifo_alloc(&priv->write_fifo, CYPRESS_BUF_SIZE, GFP_KERNEL)) {
452 		kfree(priv);
453 		return -ENOMEM;
454 	}
455 	init_waitqueue_head(&priv->delta_msr_wait);
456 
457 	usb_reset_configuration(serial->dev);
458 
459 	priv->cmd_ctrl = 0;
460 	priv->line_control = 0;
461 	priv->termios_initialized = 0;
462 	priv->rx_flags = 0;
463 	/* Default packet format setting is determined by packet size.
464 	   Anything with a size larger then 9 must have a separate
465 	   count field since the 3 bit count field is otherwise too
466 	   small.  Otherwise we can use the slightly more compact
467 	   format.  This is in accordance with the cypress_m8 serial
468 	   converter app note. */
469 	if (port->interrupt_out_size > 9)
470 		priv->pkt_fmt = packet_format_1;
471 	else
472 		priv->pkt_fmt = packet_format_2;
473 
474 	if (interval > 0) {
475 		priv->write_urb_interval = interval;
476 		priv->read_urb_interval = interval;
477 		dbg("%s - port %d read & write intervals forced to %d",
478 		    __func__, port->number, interval);
479 	} else {
480 		priv->write_urb_interval = port->interrupt_out_urb->interval;
481 		priv->read_urb_interval = port->interrupt_in_urb->interval;
482 		dbg("%s - port %d intervals: read=%d write=%d",
483 		    __func__, port->number,
484 		    priv->read_urb_interval, priv->write_urb_interval);
485 	}
486 	usb_set_serial_port_data(port, priv);
487 
488 	return 0;
489 }
490 
491 
492 static int cypress_earthmate_startup(struct usb_serial *serial)
493 {
494 	struct cypress_private *priv;
495 	struct usb_serial_port *port = serial->port[0];
496 
497 	if (generic_startup(serial)) {
498 		dbg("%s - Failed setting up port %d", __func__,
499 				port->number);
500 		return 1;
501 	}
502 
503 	priv = usb_get_serial_port_data(port);
504 	priv->chiptype = CT_EARTHMATE;
505 	/* All Earthmate devices use the separated-count packet
506 	   format!  Idiotic. */
507 	priv->pkt_fmt = packet_format_1;
508 	if (serial->dev->descriptor.idProduct !=
509 				cpu_to_le16(PRODUCT_ID_EARTHMATEUSB)) {
510 		/* The old original USB Earthmate seemed able to
511 		   handle GET_CONFIG requests; everything they've
512 		   produced since that time crashes if this command is
513 		   attempted :-( */
514 		dbg("%s - Marking this device as unsafe for GET_CONFIG "
515 		    "commands", __func__);
516 		priv->get_cfg_unsafe = !0;
517 	}
518 
519 	return 0;
520 } /* cypress_earthmate_startup */
521 
522 
523 static int cypress_hidcom_startup(struct usb_serial *serial)
524 {
525 	struct cypress_private *priv;
526 
527 	if (generic_startup(serial)) {
528 		dbg("%s - Failed setting up port %d", __func__,
529 				serial->port[0]->number);
530 		return 1;
531 	}
532 
533 	priv = usb_get_serial_port_data(serial->port[0]);
534 	priv->chiptype = CT_CYPHIDCOM;
535 
536 	return 0;
537 } /* cypress_hidcom_startup */
538 
539 
540 static int cypress_ca42v2_startup(struct usb_serial *serial)
541 {
542 	struct cypress_private *priv;
543 
544 	if (generic_startup(serial)) {
545 		dbg("%s - Failed setting up port %d", __func__,
546 				serial->port[0]->number);
547 		return 1;
548 	}
549 
550 	priv = usb_get_serial_port_data(serial->port[0]);
551 	priv->chiptype = CT_CA42V2;
552 
553 	return 0;
554 } /* cypress_ca42v2_startup */
555 
556 
557 static void cypress_release(struct usb_serial *serial)
558 {
559 	struct cypress_private *priv;
560 
561 	/* all open ports are closed at this point */
562 	priv = usb_get_serial_port_data(serial->port[0]);
563 
564 	if (priv) {
565 		kfifo_free(&priv->write_fifo);
566 		kfree(priv);
567 	}
568 }
569 
570 
571 static int cypress_open(struct tty_struct *tty, struct usb_serial_port *port)
572 {
573 	struct cypress_private *priv = usb_get_serial_port_data(port);
574 	struct usb_serial *serial = port->serial;
575 	unsigned long flags;
576 	int result = 0;
577 
578 	if (!priv->comm_is_ok)
579 		return -EIO;
580 
581 	/* clear halts before open */
582 	usb_clear_halt(serial->dev, 0x81);
583 	usb_clear_halt(serial->dev, 0x02);
584 
585 	spin_lock_irqsave(&priv->lock, flags);
586 	/* reset read/write statistics */
587 	priv->bytes_in = 0;
588 	priv->bytes_out = 0;
589 	priv->cmd_count = 0;
590 	priv->rx_flags = 0;
591 	spin_unlock_irqrestore(&priv->lock, flags);
592 
593 	/* Set termios */
594 	cypress_send(port);
595 
596 	if (tty)
597 		cypress_set_termios(tty, port, &priv->tmp_termios);
598 
599 	/* setup the port and start reading from the device */
600 	if (!port->interrupt_in_urb) {
601 		dev_err(&port->dev, "%s - interrupt_in_urb is empty!\n",
602 			__func__);
603 		return -1;
604 	}
605 
606 	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
607 		usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
608 		port->interrupt_in_urb->transfer_buffer,
609 		port->interrupt_in_urb->transfer_buffer_length,
610 		cypress_read_int_callback, port, priv->read_urb_interval);
611 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
612 
613 	if (result) {
614 		dev_err(&port->dev,
615 			"%s - failed submitting read urb, error %d\n",
616 							__func__, result);
617 		cypress_set_dead(port);
618 	}
619 	port->port.drain_delay = 256;
620 	return result;
621 } /* cypress_open */
622 
623 static void cypress_dtr_rts(struct usb_serial_port *port, int on)
624 {
625 	struct cypress_private *priv = usb_get_serial_port_data(port);
626 	/* drop dtr and rts */
627 	spin_lock_irq(&priv->lock);
628 	if (on == 0)
629 		priv->line_control = 0;
630 	else
631 		priv->line_control = CONTROL_DTR | CONTROL_RTS;
632 	priv->cmd_ctrl = 1;
633 	spin_unlock_irq(&priv->lock);
634 	cypress_write(NULL, port, NULL, 0);
635 }
636 
637 static void cypress_close(struct usb_serial_port *port)
638 {
639 	struct cypress_private *priv = usb_get_serial_port_data(port);
640 	unsigned long flags;
641 
642 	/* writing is potentially harmful, lock must be taken */
643 	mutex_lock(&port->serial->disc_mutex);
644 	if (port->serial->disconnected) {
645 		mutex_unlock(&port->serial->disc_mutex);
646 		return;
647 	}
648 	spin_lock_irqsave(&priv->lock, flags);
649 	kfifo_reset_out(&priv->write_fifo);
650 	spin_unlock_irqrestore(&priv->lock, flags);
651 
652 	dbg("%s - stopping urbs", __func__);
653 	usb_kill_urb(port->interrupt_in_urb);
654 	usb_kill_urb(port->interrupt_out_urb);
655 
656 	if (stats)
657 		dev_info(&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
658 			priv->bytes_in, priv->bytes_out, priv->cmd_count);
659 	mutex_unlock(&port->serial->disc_mutex);
660 } /* cypress_close */
661 
662 
663 static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
664 					const unsigned char *buf, int count)
665 {
666 	struct cypress_private *priv = usb_get_serial_port_data(port);
667 
668 	dbg("%s - port %d, %d bytes", __func__, port->number, count);
669 
670 	/* line control commands, which need to be executed immediately,
671 	   are not put into the buffer for obvious reasons.
672 	 */
673 	if (priv->cmd_ctrl) {
674 		count = 0;
675 		goto finish;
676 	}
677 
678 	if (!count)
679 		return count;
680 
681 	count = kfifo_in_locked(&priv->write_fifo, buf, count, &priv->lock);
682 
683 finish:
684 	cypress_send(port);
685 
686 	return count;
687 } /* cypress_write */
688 
689 
690 static void cypress_send(struct usb_serial_port *port)
691 {
692 	int count = 0, result, offset, actual_size;
693 	struct cypress_private *priv = usb_get_serial_port_data(port);
694 	unsigned long flags;
695 
696 	if (!priv->comm_is_ok)
697 		return;
698 
699 	dbg("%s - interrupt out size is %d", __func__,
700 						port->interrupt_out_size);
701 
702 	spin_lock_irqsave(&priv->lock, flags);
703 	if (priv->write_urb_in_use) {
704 		dbg("%s - can't write, urb in use", __func__);
705 		spin_unlock_irqrestore(&priv->lock, flags);
706 		return;
707 	}
708 	spin_unlock_irqrestore(&priv->lock, flags);
709 
710 	/* clear buffer */
711 	memset(port->interrupt_out_urb->transfer_buffer, 0,
712 						port->interrupt_out_size);
713 
714 	spin_lock_irqsave(&priv->lock, flags);
715 	switch (priv->pkt_fmt) {
716 	default:
717 	case packet_format_1:
718 		/* this is for the CY7C64013... */
719 		offset = 2;
720 		port->interrupt_out_buffer[0] = priv->line_control;
721 		break;
722 	case packet_format_2:
723 		/* this is for the CY7C63743... */
724 		offset = 1;
725 		port->interrupt_out_buffer[0] = priv->line_control;
726 		break;
727 	}
728 
729 	if (priv->line_control & CONTROL_RESET)
730 		priv->line_control &= ~CONTROL_RESET;
731 
732 	if (priv->cmd_ctrl) {
733 		priv->cmd_count++;
734 		dbg("%s - line control command being issued", __func__);
735 		spin_unlock_irqrestore(&priv->lock, flags);
736 		goto send;
737 	} else
738 		spin_unlock_irqrestore(&priv->lock, flags);
739 
740 	count = kfifo_out_locked(&priv->write_fifo,
741 					&port->interrupt_out_buffer[offset],
742 					port->interrupt_out_size - offset,
743 					&priv->lock);
744 	if (count == 0)
745 		return;
746 
747 	switch (priv->pkt_fmt) {
748 	default:
749 	case packet_format_1:
750 		port->interrupt_out_buffer[1] = count;
751 		break;
752 	case packet_format_2:
753 		port->interrupt_out_buffer[0] |= count;
754 	}
755 
756 	dbg("%s - count is %d", __func__, count);
757 
758 send:
759 	spin_lock_irqsave(&priv->lock, flags);
760 	priv->write_urb_in_use = 1;
761 	spin_unlock_irqrestore(&priv->lock, flags);
762 
763 	if (priv->cmd_ctrl)
764 		actual_size = 1;
765 	else
766 		actual_size = count +
767 			      (priv->pkt_fmt == packet_format_1 ? 2 : 1);
768 
769 	usb_serial_debug_data(debug, &port->dev, __func__,
770 		port->interrupt_out_size,
771 		port->interrupt_out_urb->transfer_buffer);
772 
773 	usb_fill_int_urb(port->interrupt_out_urb, port->serial->dev,
774 		usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
775 		port->interrupt_out_buffer, port->interrupt_out_size,
776 		cypress_write_int_callback, port, priv->write_urb_interval);
777 	result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
778 	if (result) {
779 		dev_err_console(port,
780 				"%s - failed submitting write urb, error %d\n",
781 							__func__, result);
782 		priv->write_urb_in_use = 0;
783 		cypress_set_dead(port);
784 	}
785 
786 	spin_lock_irqsave(&priv->lock, flags);
787 	if (priv->cmd_ctrl)
788 		priv->cmd_ctrl = 0;
789 
790 	/* do not count the line control and size bytes */
791 	priv->bytes_out += count;
792 	spin_unlock_irqrestore(&priv->lock, flags);
793 
794 	usb_serial_port_softint(port);
795 } /* cypress_send */
796 
797 
798 /* returns how much space is available in the soft buffer */
799 static int cypress_write_room(struct tty_struct *tty)
800 {
801 	struct usb_serial_port *port = tty->driver_data;
802 	struct cypress_private *priv = usb_get_serial_port_data(port);
803 	int room = 0;
804 	unsigned long flags;
805 
806 	spin_lock_irqsave(&priv->lock, flags);
807 	room = kfifo_avail(&priv->write_fifo);
808 	spin_unlock_irqrestore(&priv->lock, flags);
809 
810 	dbg("%s - returns %d", __func__, room);
811 	return room;
812 }
813 
814 
815 static int cypress_tiocmget(struct tty_struct *tty)
816 {
817 	struct usb_serial_port *port = tty->driver_data;
818 	struct cypress_private *priv = usb_get_serial_port_data(port);
819 	__u8 status, control;
820 	unsigned int result = 0;
821 	unsigned long flags;
822 
823 	spin_lock_irqsave(&priv->lock, flags);
824 	control = priv->line_control;
825 	status = priv->current_status;
826 	spin_unlock_irqrestore(&priv->lock, flags);
827 
828 	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
829 		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
830 		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
831 		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
832 		| ((status & UART_RI)         ? TIOCM_RI  : 0)
833 		| ((status & UART_CD)         ? TIOCM_CD  : 0);
834 
835 	dbg("%s - result = %x", __func__, result);
836 
837 	return result;
838 }
839 
840 
841 static int cypress_tiocmset(struct tty_struct *tty,
842 			       unsigned int set, unsigned int clear)
843 {
844 	struct usb_serial_port *port = tty->driver_data;
845 	struct cypress_private *priv = usb_get_serial_port_data(port);
846 	unsigned long flags;
847 
848 	spin_lock_irqsave(&priv->lock, flags);
849 	if (set & TIOCM_RTS)
850 		priv->line_control |= CONTROL_RTS;
851 	if (set & TIOCM_DTR)
852 		priv->line_control |= CONTROL_DTR;
853 	if (clear & TIOCM_RTS)
854 		priv->line_control &= ~CONTROL_RTS;
855 	if (clear & TIOCM_DTR)
856 		priv->line_control &= ~CONTROL_DTR;
857 	priv->cmd_ctrl = 1;
858 	spin_unlock_irqrestore(&priv->lock, flags);
859 
860 	return cypress_write(tty, port, NULL, 0);
861 }
862 
863 
864 static int cypress_ioctl(struct tty_struct *tty,
865 					unsigned int cmd, unsigned long arg)
866 {
867 	struct usb_serial_port *port = tty->driver_data;
868 	struct cypress_private *priv = usb_get_serial_port_data(port);
869 
870 	dbg("%s - port %d, cmd 0x%.4x", __func__, port->number, cmd);
871 
872 	switch (cmd) {
873 	/* This code comes from drivers/char/serial.c and ftdi_sio.c */
874 	case TIOCMIWAIT:
875 		while (priv != NULL) {
876 			interruptible_sleep_on(&priv->delta_msr_wait);
877 			/* see if a signal did it */
878 			if (signal_pending(current))
879 				return -ERESTARTSYS;
880 			else {
881 				char diff = priv->diff_status;
882 				if (diff == 0)
883 					return -EIO; /* no change => error */
884 
885 				/* consume all events */
886 				priv->diff_status = 0;
887 
888 				/* return 0 if caller wanted to know about
889 				   these bits */
890 				if (((arg & TIOCM_RNG) && (diff & UART_RI)) ||
891 				    ((arg & TIOCM_DSR) && (diff & UART_DSR)) ||
892 				    ((arg & TIOCM_CD) && (diff & UART_CD)) ||
893 				    ((arg & TIOCM_CTS) && (diff & UART_CTS)))
894 					return 0;
895 				/* otherwise caller can't care less about what
896 				 * happened, and so we continue to wait for
897 				 * more events.
898 				 */
899 			}
900 		}
901 		return 0;
902 	default:
903 		break;
904 	}
905 	dbg("%s - arg not supported - it was 0x%04x - check include/asm/ioctls.h", __func__, cmd);
906 	return -ENOIOCTLCMD;
907 } /* cypress_ioctl */
908 
909 
910 static void cypress_set_termios(struct tty_struct *tty,
911 	struct usb_serial_port *port, struct ktermios *old_termios)
912 {
913 	struct cypress_private *priv = usb_get_serial_port_data(port);
914 	int data_bits, stop_bits, parity_type, parity_enable;
915 	unsigned cflag, iflag;
916 	unsigned long flags;
917 	__u8 oldlines;
918 	int linechange = 0;
919 
920 	spin_lock_irqsave(&priv->lock, flags);
921 	/* We can't clean this one up as we don't know the device type
922 	   early enough */
923 	if (!priv->termios_initialized) {
924 		if (priv->chiptype == CT_EARTHMATE) {
925 			*(tty->termios) = tty_std_termios;
926 			tty->termios->c_cflag = B4800 | CS8 | CREAD | HUPCL |
927 				CLOCAL;
928 			tty->termios->c_ispeed = 4800;
929 			tty->termios->c_ospeed = 4800;
930 		} else if (priv->chiptype == CT_CYPHIDCOM) {
931 			*(tty->termios) = tty_std_termios;
932 			tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL |
933 				CLOCAL;
934 			tty->termios->c_ispeed = 9600;
935 			tty->termios->c_ospeed = 9600;
936 		} else if (priv->chiptype == CT_CA42V2) {
937 			*(tty->termios) = tty_std_termios;
938 			tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL |
939 				CLOCAL;
940 			tty->termios->c_ispeed = 9600;
941 			tty->termios->c_ospeed = 9600;
942 		}
943 		priv->termios_initialized = 1;
944 	}
945 	spin_unlock_irqrestore(&priv->lock, flags);
946 
947 	/* Unsupported features need clearing */
948 	tty->termios->c_cflag &= ~(CMSPAR|CRTSCTS);
949 
950 	cflag = tty->termios->c_cflag;
951 	iflag = tty->termios->c_iflag;
952 
953 	/* check if there are new settings */
954 	if (old_termios) {
955 		spin_lock_irqsave(&priv->lock, flags);
956 		priv->tmp_termios = *(tty->termios);
957 		spin_unlock_irqrestore(&priv->lock, flags);
958 	}
959 
960 	/* set number of data bits, parity, stop bits */
961 	/* when parity is disabled the parity type bit is ignored */
962 
963 	/* 1 means 2 stop bits, 0 means 1 stop bit */
964 	stop_bits = cflag & CSTOPB ? 1 : 0;
965 
966 	if (cflag & PARENB) {
967 		parity_enable = 1;
968 		/* 1 means odd parity, 0 means even parity */
969 		parity_type = cflag & PARODD ? 1 : 0;
970 	} else
971 		parity_enable = parity_type = 0;
972 
973 	switch (cflag & CSIZE) {
974 	case CS5:
975 		data_bits = 0;
976 		break;
977 	case CS6:
978 		data_bits = 1;
979 		break;
980 	case CS7:
981 		data_bits = 2;
982 		break;
983 	case CS8:
984 		data_bits = 3;
985 		break;
986 	default:
987 		dev_err(&port->dev, "%s - CSIZE was set, but not CS5-CS8\n",
988 			__func__);
989 		data_bits = 3;
990 	}
991 	spin_lock_irqsave(&priv->lock, flags);
992 	oldlines = priv->line_control;
993 	if ((cflag & CBAUD) == B0) {
994 		/* drop dtr and rts */
995 		dbg("%s - dropping the lines, baud rate 0bps", __func__);
996 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
997 	} else
998 		priv->line_control = (CONTROL_DTR | CONTROL_RTS);
999 	spin_unlock_irqrestore(&priv->lock, flags);
1000 
1001 	dbg("%s - sending %d stop_bits, %d parity_enable, %d parity_type, "
1002 			"%d data_bits (+5)", __func__, stop_bits,
1003 			parity_enable, parity_type, data_bits);
1004 
1005 	cypress_serial_control(tty, port, tty_get_baud_rate(tty),
1006 			data_bits, stop_bits,
1007 			parity_enable, parity_type,
1008 			0, CYPRESS_SET_CONFIG);
1009 
1010 	/* we perform a CYPRESS_GET_CONFIG so that the current settings are
1011 	 * filled into the private structure this should confirm that all is
1012 	 * working if it returns what we just set */
1013 	cypress_serial_control(tty, port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
1014 
1015 	/* Here we can define custom tty settings for devices; the main tty
1016 	 * termios flag base comes from empeg.c */
1017 
1018 	spin_lock_irqsave(&priv->lock, flags);
1019 	if (priv->chiptype == CT_EARTHMATE && priv->baud_rate == 4800) {
1020 		dbg("Using custom termios settings for a baud rate of "
1021 				"4800bps.");
1022 		/* define custom termios settings for NMEA protocol */
1023 
1024 		tty->termios->c_iflag /* input modes - */
1025 			&= ~(IGNBRK  /* disable ignore break */
1026 			| BRKINT     /* disable break causes interrupt */
1027 			| PARMRK     /* disable mark parity errors */
1028 			| ISTRIP     /* disable clear high bit of input char */
1029 			| INLCR      /* disable translate NL to CR */
1030 			| IGNCR      /* disable ignore CR */
1031 			| ICRNL      /* disable translate CR to NL */
1032 			| IXON);     /* disable enable XON/XOFF flow control */
1033 
1034 		tty->termios->c_oflag /* output modes */
1035 			&= ~OPOST;    /* disable postprocess output char */
1036 
1037 		tty->termios->c_lflag /* line discipline modes */
1038 			&= ~(ECHO     /* disable echo input characters */
1039 			| ECHONL      /* disable echo new line */
1040 			| ICANON      /* disable erase, kill, werase, and rprnt
1041 					 special characters */
1042 			| ISIG        /* disable interrupt, quit, and suspend
1043 					 special characters */
1044 			| IEXTEN);    /* disable non-POSIX special characters */
1045 	} /* CT_CYPHIDCOM: Application should handle this for device */
1046 
1047 	linechange = (priv->line_control != oldlines);
1048 	spin_unlock_irqrestore(&priv->lock, flags);
1049 
1050 	/* if necessary, set lines */
1051 	if (linechange) {
1052 		priv->cmd_ctrl = 1;
1053 		cypress_write(tty, port, NULL, 0);
1054 	}
1055 } /* cypress_set_termios */
1056 
1057 
1058 /* returns amount of data still left in soft buffer */
1059 static int cypress_chars_in_buffer(struct tty_struct *tty)
1060 {
1061 	struct usb_serial_port *port = tty->driver_data;
1062 	struct cypress_private *priv = usb_get_serial_port_data(port);
1063 	int chars = 0;
1064 	unsigned long flags;
1065 
1066 	spin_lock_irqsave(&priv->lock, flags);
1067 	chars = kfifo_len(&priv->write_fifo);
1068 	spin_unlock_irqrestore(&priv->lock, flags);
1069 
1070 	dbg("%s - returns %d", __func__, chars);
1071 	return chars;
1072 }
1073 
1074 
1075 static void cypress_throttle(struct tty_struct *tty)
1076 {
1077 	struct usb_serial_port *port = tty->driver_data;
1078 	struct cypress_private *priv = usb_get_serial_port_data(port);
1079 
1080 	spin_lock_irq(&priv->lock);
1081 	priv->rx_flags = THROTTLED;
1082 	spin_unlock_irq(&priv->lock);
1083 }
1084 
1085 
1086 static void cypress_unthrottle(struct tty_struct *tty)
1087 {
1088 	struct usb_serial_port *port = tty->driver_data;
1089 	struct cypress_private *priv = usb_get_serial_port_data(port);
1090 	int actually_throttled, result;
1091 
1092 	spin_lock_irq(&priv->lock);
1093 	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
1094 	priv->rx_flags = 0;
1095 	spin_unlock_irq(&priv->lock);
1096 
1097 	if (!priv->comm_is_ok)
1098 		return;
1099 
1100 	if (actually_throttled) {
1101 		result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
1102 		if (result) {
1103 			dev_err(&port->dev, "%s - failed submitting read urb, "
1104 					"error %d\n", __func__, result);
1105 			cypress_set_dead(port);
1106 		}
1107 	}
1108 }
1109 
1110 
1111 static void cypress_read_int_callback(struct urb *urb)
1112 {
1113 	struct usb_serial_port *port = urb->context;
1114 	struct cypress_private *priv = usb_get_serial_port_data(port);
1115 	struct tty_struct *tty;
1116 	unsigned char *data = urb->transfer_buffer;
1117 	unsigned long flags;
1118 	char tty_flag = TTY_NORMAL;
1119 	int havedata = 0;
1120 	int bytes = 0;
1121 	int result;
1122 	int i = 0;
1123 	int status = urb->status;
1124 
1125 	switch (status) {
1126 	case 0: /* success */
1127 		break;
1128 	case -ECONNRESET:
1129 	case -ENOENT:
1130 	case -ESHUTDOWN:
1131 		/* precursor to disconnect so just go away */
1132 		return;
1133 	case -EPIPE:
1134 		/* Can't call usb_clear_halt while in_interrupt */
1135 		/* FALLS THROUGH */
1136 	default:
1137 		/* something ugly is going on... */
1138 		dev_err(&urb->dev->dev,
1139 			"%s - unexpected nonzero read status received: %d\n",
1140 							__func__, status);
1141 		cypress_set_dead(port);
1142 		return;
1143 	}
1144 
1145 	spin_lock_irqsave(&priv->lock, flags);
1146 	if (priv->rx_flags & THROTTLED) {
1147 		dbg("%s - now throttling", __func__);
1148 		priv->rx_flags |= ACTUALLY_THROTTLED;
1149 		spin_unlock_irqrestore(&priv->lock, flags);
1150 		return;
1151 	}
1152 	spin_unlock_irqrestore(&priv->lock, flags);
1153 
1154 	tty = tty_port_tty_get(&port->port);
1155 	if (!tty) {
1156 		dbg("%s - bad tty pointer - exiting", __func__);
1157 		return;
1158 	}
1159 
1160 	spin_lock_irqsave(&priv->lock, flags);
1161 	result = urb->actual_length;
1162 	switch (priv->pkt_fmt) {
1163 	default:
1164 	case packet_format_1:
1165 		/* This is for the CY7C64013... */
1166 		priv->current_status = data[0] & 0xF8;
1167 		bytes = data[1] + 2;
1168 		i = 2;
1169 		if (bytes > 2)
1170 			havedata = 1;
1171 		break;
1172 	case packet_format_2:
1173 		/* This is for the CY7C63743... */
1174 		priv->current_status = data[0] & 0xF8;
1175 		bytes = (data[0] & 0x07) + 1;
1176 		i = 1;
1177 		if (bytes > 1)
1178 			havedata = 1;
1179 		break;
1180 	}
1181 	spin_unlock_irqrestore(&priv->lock, flags);
1182 	if (result < bytes) {
1183 		dbg("%s - wrong packet size - received %d bytes but packet "
1184 		    "said %d bytes", __func__, result, bytes);
1185 		goto continue_read;
1186 	}
1187 
1188 	usb_serial_debug_data(debug, &port->dev, __func__,
1189 						urb->actual_length, data);
1190 
1191 	spin_lock_irqsave(&priv->lock, flags);
1192 	/* check to see if status has changed */
1193 	if (priv->current_status != priv->prev_status) {
1194 		priv->diff_status |= priv->current_status ^
1195 			priv->prev_status;
1196 		wake_up_interruptible(&priv->delta_msr_wait);
1197 		priv->prev_status = priv->current_status;
1198 	}
1199 	spin_unlock_irqrestore(&priv->lock, flags);
1200 
1201 	/* hangup, as defined in acm.c... this might be a bad place for it
1202 	 * though */
1203 	if (tty && !(tty->termios->c_cflag & CLOCAL) &&
1204 			!(priv->current_status & UART_CD)) {
1205 		dbg("%s - calling hangup", __func__);
1206 		tty_hangup(tty);
1207 		goto continue_read;
1208 	}
1209 
1210 	/* There is one error bit... I'm assuming it is a parity error
1211 	 * indicator as the generic firmware will set this bit to 1 if a
1212 	 * parity error occurs.
1213 	 * I can not find reference to any other error events. */
1214 	spin_lock_irqsave(&priv->lock, flags);
1215 	if (priv->current_status & CYP_ERROR) {
1216 		spin_unlock_irqrestore(&priv->lock, flags);
1217 		tty_flag = TTY_PARITY;
1218 		dbg("%s - Parity Error detected", __func__);
1219 	} else
1220 		spin_unlock_irqrestore(&priv->lock, flags);
1221 
1222 	/* process read if there is data other than line status */
1223 	if (tty && bytes > i) {
1224 		tty_insert_flip_string_fixed_flag(tty, data + i,
1225 				tty_flag, bytes - i);
1226 		tty_flip_buffer_push(tty);
1227 	}
1228 
1229 	spin_lock_irqsave(&priv->lock, flags);
1230 	/* control and status byte(s) are also counted */
1231 	priv->bytes_in += bytes;
1232 	spin_unlock_irqrestore(&priv->lock, flags);
1233 
1234 continue_read:
1235 	tty_kref_put(tty);
1236 
1237 	/* Continue trying to always read */
1238 
1239 	if (priv->comm_is_ok) {
1240 		usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1241 				usb_rcvintpipe(port->serial->dev,
1242 					port->interrupt_in_endpointAddress),
1243 				port->interrupt_in_urb->transfer_buffer,
1244 				port->interrupt_in_urb->transfer_buffer_length,
1245 				cypress_read_int_callback, port,
1246 				priv->read_urb_interval);
1247 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1248 		if (result && result != -EPERM) {
1249 			dev_err(&urb->dev->dev, "%s - failed resubmitting "
1250 					"read urb, error %d\n", __func__,
1251 					result);
1252 			cypress_set_dead(port);
1253 		}
1254 	}
1255 } /* cypress_read_int_callback */
1256 
1257 
1258 static void cypress_write_int_callback(struct urb *urb)
1259 {
1260 	struct usb_serial_port *port = urb->context;
1261 	struct cypress_private *priv = usb_get_serial_port_data(port);
1262 	int result;
1263 	int status = urb->status;
1264 
1265 	switch (status) {
1266 	case 0:
1267 		/* success */
1268 		break;
1269 	case -ECONNRESET:
1270 	case -ENOENT:
1271 	case -ESHUTDOWN:
1272 		/* this urb is terminated, clean up */
1273 		dbg("%s - urb shutting down with status: %d",
1274 						__func__, status);
1275 		priv->write_urb_in_use = 0;
1276 		return;
1277 	case -EPIPE: /* no break needed; clear halt and resubmit */
1278 		if (!priv->comm_is_ok)
1279 			break;
1280 		usb_clear_halt(port->serial->dev, 0x02);
1281 		/* error in the urb, so we have to resubmit it */
1282 		dbg("%s - nonzero write bulk status received: %d",
1283 			__func__, status);
1284 		port->interrupt_out_urb->transfer_buffer_length = 1;
1285 		result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
1286 		if (!result)
1287 			return;
1288 		dev_err(&urb->dev->dev,
1289 			"%s - failed resubmitting write urb, error %d\n",
1290 							__func__, result);
1291 		cypress_set_dead(port);
1292 		break;
1293 	default:
1294 		dev_err(&urb->dev->dev,
1295 			 "%s - unexpected nonzero write status received: %d\n",
1296 							__func__, status);
1297 		cypress_set_dead(port);
1298 		break;
1299 	}
1300 	priv->write_urb_in_use = 0;
1301 
1302 	/* send any buffered data */
1303 	cypress_send(port);
1304 }
1305 
1306 module_usb_serial_driver(serial_drivers, id_table_combined);
1307 
1308 MODULE_AUTHOR(DRIVER_AUTHOR);
1309 MODULE_DESCRIPTION(DRIVER_DESC);
1310 MODULE_VERSION(DRIVER_VERSION);
1311 MODULE_LICENSE("GPL");
1312 
1313 module_param(debug, bool, S_IRUGO | S_IWUSR);
1314 MODULE_PARM_DESC(debug, "Debug enabled or not");
1315 module_param(stats, bool, S_IRUGO | S_IWUSR);
1316 MODULE_PARM_DESC(stats, "Enable statistics or not");
1317 module_param(interval, int, S_IRUGO | S_IWUSR);
1318 MODULE_PARM_DESC(interval, "Overrides interrupt interval");
1319 module_param(unstable_bauds, bool, S_IRUGO | S_IWUSR);
1320 MODULE_PARM_DESC(unstable_bauds, "Allow unstable baud rates");
1321