xref: /linux/drivers/usb/serial/cypress_m8.c (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
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/slab.h>
31 #include <linux/tty.h>
32 #include <linux/tty_driver.h>
33 #include <linux/tty_flip.h>
34 #include <linux/module.h>
35 #include <linux/moduleparam.h>
36 #include <linux/spinlock.h>
37 #include <linux/usb.h>
38 #include <linux/usb/serial.h>
39 #include <linux/serial.h>
40 #include <linux/kfifo.h>
41 #include <linux/delay.h>
42 #include <linux/uaccess.h>
43 #include <asm/unaligned.h>
44 
45 #include "cypress_m8.h"
46 
47 
48 static bool stats;
49 static int interval;
50 static bool unstable_bauds;
51 
52 #define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
53 #define DRIVER_DESC "Cypress USB to Serial Driver"
54 
55 /* write buffer size defines */
56 #define CYPRESS_BUF_SIZE	1024
57 
58 static const struct usb_device_id id_table_earthmate[] = {
59 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
60 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
61 	{ }						/* Terminating entry */
62 };
63 
64 static const struct usb_device_id id_table_cyphidcomrs232[] = {
65 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
66 	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
67 	{ USB_DEVICE(VENDOR_ID_FRWD, PRODUCT_ID_CYPHIDCOM_FRWD) },
68 	{ }						/* Terminating entry */
69 };
70 
71 static const struct usb_device_id id_table_nokiaca42v2[] = {
72 	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
73 	{ }						/* Terminating entry */
74 };
75 
76 static const struct usb_device_id id_table_combined[] = {
77 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
78 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
79 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
80 	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
81 	{ USB_DEVICE(VENDOR_ID_FRWD, PRODUCT_ID_CYPHIDCOM_FRWD) },
82 	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
83 	{ }						/* Terminating entry */
84 };
85 
86 MODULE_DEVICE_TABLE(usb, id_table_combined);
87 
88 enum packet_format {
89 	packet_format_1,  /* b0:status, b1:payload count */
90 	packet_format_2   /* b0[7:3]:status, b0[2:0]:payload count */
91 };
92 
93 struct cypress_private {
94 	spinlock_t lock;		   /* private lock */
95 	int chiptype;			   /* identifier of device, for quirks/etc */
96 	int bytes_in;			   /* used for statistics */
97 	int bytes_out;			   /* used for statistics */
98 	int cmd_count;			   /* used for statistics */
99 	int cmd_ctrl;			   /* always set this to 1 before issuing a command */
100 	struct kfifo write_fifo;	   /* write fifo */
101 	int write_urb_in_use;		   /* write urb in use indicator */
102 	int write_urb_interval;            /* interval to use for write urb */
103 	int read_urb_interval;             /* interval to use for read urb */
104 	int comm_is_ok;                    /* true if communication is (still) ok */
105 	int termios_initialized;
106 	__u8 line_control;	   	   /* holds dtr / rts value */
107 	__u8 current_status;	   	   /* received from last read - info on dsr,cts,cd,ri,etc */
108 	__u8 current_config;	   	   /* stores the current configuration byte */
109 	__u8 rx_flags;			   /* throttling - used from whiteheat/ftdi_sio */
110 	enum packet_format pkt_fmt;	   /* format to use for packet send / receive */
111 	int get_cfg_unsafe;		   /* If true, the CYPRESS_GET_CONFIG is unsafe */
112 	int baud_rate;			   /* stores current baud rate in
113 					      integer form */
114 	int isthrottled;		   /* if throttled, discard reads */
115 	char prev_status;		   /* used for TIOCMIWAIT */
116 	/* we pass a pointer to this as the argument sent to
117 	   cypress_set_termios old_termios */
118 	struct ktermios tmp_termios; 	   /* stores the old termios settings */
119 };
120 
121 /* function prototypes for the Cypress USB to serial device */
122 static int  cypress_earthmate_port_probe(struct usb_serial_port *port);
123 static int  cypress_hidcom_port_probe(struct usb_serial_port *port);
124 static int  cypress_ca42v2_port_probe(struct usb_serial_port *port);
125 static int  cypress_port_remove(struct usb_serial_port *port);
126 static int  cypress_open(struct tty_struct *tty, struct usb_serial_port *port);
127 static void cypress_close(struct usb_serial_port *port);
128 static void cypress_dtr_rts(struct usb_serial_port *port, int on);
129 static int  cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
130 			const unsigned char *buf, int count);
131 static void cypress_send(struct usb_serial_port *port);
132 static int  cypress_write_room(struct tty_struct *tty);
133 static void cypress_set_termios(struct tty_struct *tty,
134 			struct usb_serial_port *port, struct ktermios *old);
135 static int  cypress_tiocmget(struct tty_struct *tty);
136 static int  cypress_tiocmset(struct tty_struct *tty,
137 			unsigned int set, unsigned int clear);
138 static int  cypress_chars_in_buffer(struct tty_struct *tty);
139 static void cypress_throttle(struct tty_struct *tty);
140 static void cypress_unthrottle(struct tty_struct *tty);
141 static void cypress_set_dead(struct usb_serial_port *port);
142 static void cypress_read_int_callback(struct urb *urb);
143 static void cypress_write_int_callback(struct urb *urb);
144 
145 static struct usb_serial_driver cypress_earthmate_device = {
146 	.driver = {
147 		.owner =		THIS_MODULE,
148 		.name =			"earthmate",
149 	},
150 	.description =			"DeLorme Earthmate USB",
151 	.id_table =			id_table_earthmate,
152 	.num_ports =			1,
153 	.port_probe =			cypress_earthmate_port_probe,
154 	.port_remove =			cypress_port_remove,
155 	.open =				cypress_open,
156 	.close =			cypress_close,
157 	.dtr_rts =			cypress_dtr_rts,
158 	.write =			cypress_write,
159 	.write_room =			cypress_write_room,
160 	.set_termios =			cypress_set_termios,
161 	.tiocmget =			cypress_tiocmget,
162 	.tiocmset =			cypress_tiocmset,
163 	.tiocmiwait =			usb_serial_generic_tiocmiwait,
164 	.chars_in_buffer =		cypress_chars_in_buffer,
165 	.throttle =		 	cypress_throttle,
166 	.unthrottle =			cypress_unthrottle,
167 	.read_int_callback =		cypress_read_int_callback,
168 	.write_int_callback =		cypress_write_int_callback,
169 };
170 
171 static struct usb_serial_driver cypress_hidcom_device = {
172 	.driver = {
173 		.owner =		THIS_MODULE,
174 		.name =			"cyphidcom",
175 	},
176 	.description =			"HID->COM RS232 Adapter",
177 	.id_table =			id_table_cyphidcomrs232,
178 	.num_ports =			1,
179 	.port_probe =			cypress_hidcom_port_probe,
180 	.port_remove =			cypress_port_remove,
181 	.open =				cypress_open,
182 	.close =			cypress_close,
183 	.dtr_rts =			cypress_dtr_rts,
184 	.write =			cypress_write,
185 	.write_room =			cypress_write_room,
186 	.set_termios =			cypress_set_termios,
187 	.tiocmget =			cypress_tiocmget,
188 	.tiocmset =			cypress_tiocmset,
189 	.tiocmiwait =			usb_serial_generic_tiocmiwait,
190 	.chars_in_buffer =		cypress_chars_in_buffer,
191 	.throttle =			cypress_throttle,
192 	.unthrottle =			cypress_unthrottle,
193 	.read_int_callback =		cypress_read_int_callback,
194 	.write_int_callback =		cypress_write_int_callback,
195 };
196 
197 static struct usb_serial_driver cypress_ca42v2_device = {
198 	.driver = {
199 		.owner =		THIS_MODULE,
200 		.name =			"nokiaca42v2",
201 	},
202 	.description =			"Nokia CA-42 V2 Adapter",
203 	.id_table =			id_table_nokiaca42v2,
204 	.num_ports =			1,
205 	.port_probe =			cypress_ca42v2_port_probe,
206 	.port_remove =			cypress_port_remove,
207 	.open =				cypress_open,
208 	.close =			cypress_close,
209 	.dtr_rts =			cypress_dtr_rts,
210 	.write =			cypress_write,
211 	.write_room =			cypress_write_room,
212 	.set_termios =			cypress_set_termios,
213 	.tiocmget =			cypress_tiocmget,
214 	.tiocmset =			cypress_tiocmset,
215 	.tiocmiwait =			usb_serial_generic_tiocmiwait,
216 	.chars_in_buffer =		cypress_chars_in_buffer,
217 	.throttle =			cypress_throttle,
218 	.unthrottle =			cypress_unthrottle,
219 	.read_int_callback =		cypress_read_int_callback,
220 	.write_int_callback =		cypress_write_int_callback,
221 };
222 
223 static struct usb_serial_driver * const serial_drivers[] = {
224 	&cypress_earthmate_device, &cypress_hidcom_device,
225 	&cypress_ca42v2_device, NULL
226 };
227 
228 /*****************************************************************************
229  * Cypress serial helper functions
230  *****************************************************************************/
231 
232 /* FRWD Dongle hidcom needs to skip reset and speed checks */
233 static inline bool is_frwd(struct usb_device *dev)
234 {
235 	return ((le16_to_cpu(dev->descriptor.idVendor) == VENDOR_ID_FRWD) &&
236 		(le16_to_cpu(dev->descriptor.idProduct) == PRODUCT_ID_CYPHIDCOM_FRWD));
237 }
238 
239 static int analyze_baud_rate(struct usb_serial_port *port, speed_t new_rate)
240 {
241 	struct cypress_private *priv;
242 	priv = usb_get_serial_port_data(port);
243 
244 	if (unstable_bauds)
245 		return new_rate;
246 
247 	/* FRWD Dongle uses 115200 bps */
248 	if (is_frwd(port->serial->dev))
249 		return new_rate;
250 
251 	/*
252 	 * The general purpose firmware for the Cypress M8 allows for
253 	 * a maximum speed of 57600bps (I have no idea whether DeLorme
254 	 * chose to use the general purpose firmware or not), if you
255 	 * need to modify this speed setting for your own project
256 	 * please add your own chiptype and modify the code likewise.
257 	 * The Cypress HID->COM device will work successfully up to
258 	 * 115200bps (but the actual throughput is around 3kBps).
259 	 */
260 	if (port->serial->dev->speed == USB_SPEED_LOW) {
261 		/*
262 		 * Mike Isely <isely@pobox.com> 2-Feb-2008: The
263 		 * Cypress app note that describes this mechanism
264 		 * states the the low-speed part can't handle more
265 		 * than 800 bytes/sec, in which case 4800 baud is the
266 		 * safest speed for a part like that.
267 		 */
268 		if (new_rate > 4800) {
269 			dev_dbg(&port->dev,
270 				"%s - failed setting baud rate, device incapable speed %d\n",
271 				__func__, new_rate);
272 			return -1;
273 		}
274 	}
275 	switch (priv->chiptype) {
276 	case CT_EARTHMATE:
277 		if (new_rate <= 600) {
278 			/* 300 and 600 baud rates are supported under
279 			 * the generic firmware, but are not used with
280 			 * NMEA and SiRF protocols */
281 			dev_dbg(&port->dev,
282 				"%s - failed setting baud rate, unsupported speed of %d on Earthmate GPS\n",
283 				__func__, new_rate);
284 			return -1;
285 		}
286 		break;
287 	default:
288 		break;
289 	}
290 	return new_rate;
291 }
292 
293 
294 /* This function can either set or retrieve the current serial line settings */
295 static int cypress_serial_control(struct tty_struct *tty,
296 	struct usb_serial_port *port, speed_t baud_rate, int data_bits,
297 	int stop_bits, int parity_enable, int parity_type, int reset,
298 	int cypress_request_type)
299 {
300 	int new_baudrate = 0, retval = 0, tries = 0;
301 	struct cypress_private *priv;
302 	struct device *dev = &port->dev;
303 	u8 *feature_buffer;
304 	const unsigned int feature_len = 5;
305 	unsigned long flags;
306 
307 	priv = usb_get_serial_port_data(port);
308 
309 	if (!priv->comm_is_ok)
310 		return -ENODEV;
311 
312 	feature_buffer = kcalloc(feature_len, sizeof(u8), GFP_KERNEL);
313 	if (!feature_buffer)
314 		return -ENOMEM;
315 
316 	switch (cypress_request_type) {
317 	case CYPRESS_SET_CONFIG:
318 		/* 0 means 'Hang up' so doesn't change the true bit rate */
319 		new_baudrate = priv->baud_rate;
320 		if (baud_rate && baud_rate != priv->baud_rate) {
321 			dev_dbg(dev, "%s - baud rate is changing\n", __func__);
322 			retval = analyze_baud_rate(port, baud_rate);
323 			if (retval >= 0) {
324 				new_baudrate = retval;
325 				dev_dbg(dev, "%s - New baud rate set to %d\n",
326 					__func__, new_baudrate);
327 			}
328 		}
329 		dev_dbg(dev, "%s - baud rate is being sent as %d\n", __func__,
330 			new_baudrate);
331 
332 		/* fill the feature_buffer with new configuration */
333 		put_unaligned_le32(new_baudrate, feature_buffer);
334 		feature_buffer[4] |= data_bits;   /* assign data bits in 2 bit space ( max 3 ) */
335 		/* 1 bit gap */
336 		feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
337 		feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
338 		feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
339 		/* 1 bit gap */
340 		feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
341 
342 		dev_dbg(dev, "%s - device is being sent this feature report:\n", __func__);
343 		dev_dbg(dev, "%s - %02X - %02X - %02X - %02X - %02X\n", __func__,
344 			feature_buffer[0], feature_buffer[1],
345 			feature_buffer[2], feature_buffer[3],
346 			feature_buffer[4]);
347 
348 		do {
349 			retval = usb_control_msg(port->serial->dev,
350 					usb_sndctrlpipe(port->serial->dev, 0),
351 					HID_REQ_SET_REPORT,
352 					USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
353 					0x0300, 0, feature_buffer,
354 					feature_len, 500);
355 
356 			if (tries++ >= 3)
357 				break;
358 
359 		} while (retval != feature_len &&
360 			 retval != -ENODEV);
361 
362 		if (retval != feature_len) {
363 			dev_err(dev, "%s - failed sending serial line settings - %d\n",
364 				__func__, retval);
365 			cypress_set_dead(port);
366 		} else {
367 			spin_lock_irqsave(&priv->lock, flags);
368 			priv->baud_rate = new_baudrate;
369 			priv->current_config = feature_buffer[4];
370 			spin_unlock_irqrestore(&priv->lock, flags);
371 			/* If we asked for a speed change encode it */
372 			if (baud_rate)
373 				tty_encode_baud_rate(tty,
374 					new_baudrate, new_baudrate);
375 		}
376 	break;
377 	case CYPRESS_GET_CONFIG:
378 		if (priv->get_cfg_unsafe) {
379 			/* Not implemented for this device,
380 			   and if we try to do it we're likely
381 			   to crash the hardware. */
382 			retval = -ENOTTY;
383 			goto out;
384 		}
385 		dev_dbg(dev, "%s - retreiving serial line settings\n", __func__);
386 		do {
387 			retval = usb_control_msg(port->serial->dev,
388 					usb_rcvctrlpipe(port->serial->dev, 0),
389 					HID_REQ_GET_REPORT,
390 					USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
391 					0x0300, 0, feature_buffer,
392 					feature_len, 500);
393 
394 			if (tries++ >= 3)
395 				break;
396 		} while (retval != feature_len
397 						&& retval != -ENODEV);
398 
399 		if (retval != feature_len) {
400 			dev_err(dev, "%s - failed to retrieve serial line settings - %d\n",
401 				__func__, retval);
402 			cypress_set_dead(port);
403 			goto out;
404 		} else {
405 			spin_lock_irqsave(&priv->lock, flags);
406 			/* store the config in one byte, and later
407 			   use bit masks to check values */
408 			priv->current_config = feature_buffer[4];
409 			priv->baud_rate = get_unaligned_le32(feature_buffer);
410 			spin_unlock_irqrestore(&priv->lock, flags);
411 		}
412 	}
413 	spin_lock_irqsave(&priv->lock, flags);
414 	++priv->cmd_count;
415 	spin_unlock_irqrestore(&priv->lock, flags);
416 out:
417 	kfree(feature_buffer);
418 	return retval;
419 } /* cypress_serial_control */
420 
421 
422 static void cypress_set_dead(struct usb_serial_port *port)
423 {
424 	struct cypress_private *priv = usb_get_serial_port_data(port);
425 	unsigned long flags;
426 
427 	spin_lock_irqsave(&priv->lock, flags);
428 	if (!priv->comm_is_ok) {
429 		spin_unlock_irqrestore(&priv->lock, flags);
430 		return;
431 	}
432 	priv->comm_is_ok = 0;
433 	spin_unlock_irqrestore(&priv->lock, flags);
434 
435 	dev_err(&port->dev, "cypress_m8 suspending failing port %d - "
436 		"interval might be too short\n", port->port_number);
437 }
438 
439 
440 /*****************************************************************************
441  * Cypress serial driver functions
442  *****************************************************************************/
443 
444 
445 static int cypress_generic_port_probe(struct usb_serial_port *port)
446 {
447 	struct usb_serial *serial = port->serial;
448 	struct cypress_private *priv;
449 
450 	priv = kzalloc(sizeof(struct cypress_private), GFP_KERNEL);
451 	if (!priv)
452 		return -ENOMEM;
453 
454 	priv->comm_is_ok = !0;
455 	spin_lock_init(&priv->lock);
456 	if (kfifo_alloc(&priv->write_fifo, CYPRESS_BUF_SIZE, GFP_KERNEL)) {
457 		kfree(priv);
458 		return -ENOMEM;
459 	}
460 
461 	/* Skip reset for FRWD device. It is a workaound:
462 	   device hangs if it receives SET_CONFIGURE in Configured
463 	   state. */
464 	if (!is_frwd(serial->dev))
465 		usb_reset_configuration(serial->dev);
466 
467 	priv->cmd_ctrl = 0;
468 	priv->line_control = 0;
469 	priv->termios_initialized = 0;
470 	priv->rx_flags = 0;
471 	/* Default packet format setting is determined by packet size.
472 	   Anything with a size larger then 9 must have a separate
473 	   count field since the 3 bit count field is otherwise too
474 	   small.  Otherwise we can use the slightly more compact
475 	   format.  This is in accordance with the cypress_m8 serial
476 	   converter app note. */
477 	if (port->interrupt_out_size > 9)
478 		priv->pkt_fmt = packet_format_1;
479 	else
480 		priv->pkt_fmt = packet_format_2;
481 
482 	if (interval > 0) {
483 		priv->write_urb_interval = interval;
484 		priv->read_urb_interval = interval;
485 		dev_dbg(&port->dev, "%s - read & write intervals forced to %d\n",
486 			__func__, interval);
487 	} else {
488 		priv->write_urb_interval = port->interrupt_out_urb->interval;
489 		priv->read_urb_interval = port->interrupt_in_urb->interval;
490 		dev_dbg(&port->dev, "%s - intervals: read=%d write=%d\n",
491 			__func__, priv->read_urb_interval,
492 			priv->write_urb_interval);
493 	}
494 	usb_set_serial_port_data(port, priv);
495 
496 	port->port.drain_delay = 256;
497 
498 	return 0;
499 }
500 
501 
502 static int cypress_earthmate_port_probe(struct usb_serial_port *port)
503 {
504 	struct usb_serial *serial = port->serial;
505 	struct cypress_private *priv;
506 	int ret;
507 
508 	ret = cypress_generic_port_probe(port);
509 	if (ret) {
510 		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
511 		return ret;
512 	}
513 
514 	priv = usb_get_serial_port_data(port);
515 	priv->chiptype = CT_EARTHMATE;
516 	/* All Earthmate devices use the separated-count packet
517 	   format!  Idiotic. */
518 	priv->pkt_fmt = packet_format_1;
519 	if (serial->dev->descriptor.idProduct !=
520 				cpu_to_le16(PRODUCT_ID_EARTHMATEUSB)) {
521 		/* The old original USB Earthmate seemed able to
522 		   handle GET_CONFIG requests; everything they've
523 		   produced since that time crashes if this command is
524 		   attempted :-( */
525 		dev_dbg(&port->dev,
526 			"%s - Marking this device as unsafe for GET_CONFIG commands\n",
527 			__func__);
528 		priv->get_cfg_unsafe = !0;
529 	}
530 
531 	return 0;
532 }
533 
534 static int cypress_hidcom_port_probe(struct usb_serial_port *port)
535 {
536 	struct cypress_private *priv;
537 	int ret;
538 
539 	ret = cypress_generic_port_probe(port);
540 	if (ret) {
541 		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
542 		return ret;
543 	}
544 
545 	priv = usb_get_serial_port_data(port);
546 	priv->chiptype = CT_CYPHIDCOM;
547 
548 	return 0;
549 }
550 
551 static int cypress_ca42v2_port_probe(struct usb_serial_port *port)
552 {
553 	struct cypress_private *priv;
554 	int ret;
555 
556 	ret = cypress_generic_port_probe(port);
557 	if (ret) {
558 		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
559 		return ret;
560 	}
561 
562 	priv = usb_get_serial_port_data(port);
563 	priv->chiptype = CT_CA42V2;
564 
565 	return 0;
566 }
567 
568 static int cypress_port_remove(struct usb_serial_port *port)
569 {
570 	struct cypress_private *priv;
571 
572 	priv = usb_get_serial_port_data(port);
573 
574 	kfifo_free(&priv->write_fifo);
575 	kfree(priv);
576 
577 	return 0;
578 }
579 
580 static int cypress_open(struct tty_struct *tty, struct usb_serial_port *port)
581 {
582 	struct cypress_private *priv = usb_get_serial_port_data(port);
583 	struct usb_serial *serial = port->serial;
584 	unsigned long flags;
585 	int result = 0;
586 
587 	if (!priv->comm_is_ok)
588 		return -EIO;
589 
590 	/* clear halts before open */
591 	usb_clear_halt(serial->dev, 0x81);
592 	usb_clear_halt(serial->dev, 0x02);
593 
594 	spin_lock_irqsave(&priv->lock, flags);
595 	/* reset read/write statistics */
596 	priv->bytes_in = 0;
597 	priv->bytes_out = 0;
598 	priv->cmd_count = 0;
599 	priv->rx_flags = 0;
600 	spin_unlock_irqrestore(&priv->lock, flags);
601 
602 	/* Set termios */
603 	cypress_send(port);
604 
605 	if (tty)
606 		cypress_set_termios(tty, port, &priv->tmp_termios);
607 
608 	/* setup the port and start reading from the device */
609 	if (!port->interrupt_in_urb) {
610 		dev_err(&port->dev, "%s - interrupt_in_urb is empty!\n",
611 			__func__);
612 		return -1;
613 	}
614 
615 	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
616 		usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
617 		port->interrupt_in_urb->transfer_buffer,
618 		port->interrupt_in_urb->transfer_buffer_length,
619 		cypress_read_int_callback, port, priv->read_urb_interval);
620 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
621 
622 	if (result) {
623 		dev_err(&port->dev,
624 			"%s - failed submitting read urb, error %d\n",
625 							__func__, result);
626 		cypress_set_dead(port);
627 	}
628 
629 	return result;
630 } /* cypress_open */
631 
632 static void cypress_dtr_rts(struct usb_serial_port *port, int on)
633 {
634 	struct cypress_private *priv = usb_get_serial_port_data(port);
635 	/* drop dtr and rts */
636 	spin_lock_irq(&priv->lock);
637 	if (on == 0)
638 		priv->line_control = 0;
639 	else
640 		priv->line_control = CONTROL_DTR | CONTROL_RTS;
641 	priv->cmd_ctrl = 1;
642 	spin_unlock_irq(&priv->lock);
643 	cypress_write(NULL, port, NULL, 0);
644 }
645 
646 static void cypress_close(struct usb_serial_port *port)
647 {
648 	struct cypress_private *priv = usb_get_serial_port_data(port);
649 	unsigned long flags;
650 
651 	spin_lock_irqsave(&priv->lock, flags);
652 	kfifo_reset_out(&priv->write_fifo);
653 	spin_unlock_irqrestore(&priv->lock, flags);
654 
655 	dev_dbg(&port->dev, "%s - stopping urbs\n", __func__);
656 	usb_kill_urb(port->interrupt_in_urb);
657 	usb_kill_urb(port->interrupt_out_urb);
658 
659 	if (stats)
660 		dev_info(&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
661 			priv->bytes_in, priv->bytes_out, priv->cmd_count);
662 } /* cypress_close */
663 
664 
665 static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
666 					const unsigned char *buf, int count)
667 {
668 	struct cypress_private *priv = usb_get_serial_port_data(port);
669 
670 	dev_dbg(&port->dev, "%s - %d bytes\n", __func__, count);
671 
672 	/* line control commands, which need to be executed immediately,
673 	   are not put into the buffer for obvious reasons.
674 	 */
675 	if (priv->cmd_ctrl) {
676 		count = 0;
677 		goto finish;
678 	}
679 
680 	if (!count)
681 		return count;
682 
683 	count = kfifo_in_locked(&priv->write_fifo, buf, count, &priv->lock);
684 
685 finish:
686 	cypress_send(port);
687 
688 	return count;
689 } /* cypress_write */
690 
691 
692 static void cypress_send(struct usb_serial_port *port)
693 {
694 	int count = 0, result, offset, actual_size;
695 	struct cypress_private *priv = usb_get_serial_port_data(port);
696 	struct device *dev = &port->dev;
697 	unsigned long flags;
698 
699 	if (!priv->comm_is_ok)
700 		return;
701 
702 	dev_dbg(dev, "%s - interrupt out size is %d\n", __func__,
703 		port->interrupt_out_size);
704 
705 	spin_lock_irqsave(&priv->lock, flags);
706 	if (priv->write_urb_in_use) {
707 		dev_dbg(dev, "%s - can't write, urb in use\n", __func__);
708 		spin_unlock_irqrestore(&priv->lock, flags);
709 		return;
710 	}
711 	spin_unlock_irqrestore(&priv->lock, flags);
712 
713 	/* clear buffer */
714 	memset(port->interrupt_out_urb->transfer_buffer, 0,
715 						port->interrupt_out_size);
716 
717 	spin_lock_irqsave(&priv->lock, flags);
718 	switch (priv->pkt_fmt) {
719 	default:
720 	case packet_format_1:
721 		/* this is for the CY7C64013... */
722 		offset = 2;
723 		port->interrupt_out_buffer[0] = priv->line_control;
724 		break;
725 	case packet_format_2:
726 		/* this is for the CY7C63743... */
727 		offset = 1;
728 		port->interrupt_out_buffer[0] = priv->line_control;
729 		break;
730 	}
731 
732 	if (priv->line_control & CONTROL_RESET)
733 		priv->line_control &= ~CONTROL_RESET;
734 
735 	if (priv->cmd_ctrl) {
736 		priv->cmd_count++;
737 		dev_dbg(dev, "%s - line control command being issued\n", __func__);
738 		spin_unlock_irqrestore(&priv->lock, flags);
739 		goto send;
740 	} else
741 		spin_unlock_irqrestore(&priv->lock, flags);
742 
743 	count = kfifo_out_locked(&priv->write_fifo,
744 					&port->interrupt_out_buffer[offset],
745 					port->interrupt_out_size - offset,
746 					&priv->lock);
747 	if (count == 0)
748 		return;
749 
750 	switch (priv->pkt_fmt) {
751 	default:
752 	case packet_format_1:
753 		port->interrupt_out_buffer[1] = count;
754 		break;
755 	case packet_format_2:
756 		port->interrupt_out_buffer[0] |= count;
757 	}
758 
759 	dev_dbg(dev, "%s - count is %d\n", __func__, count);
760 
761 send:
762 	spin_lock_irqsave(&priv->lock, flags);
763 	priv->write_urb_in_use = 1;
764 	spin_unlock_irqrestore(&priv->lock, flags);
765 
766 	if (priv->cmd_ctrl)
767 		actual_size = 1;
768 	else
769 		actual_size = count +
770 			      (priv->pkt_fmt == packet_format_1 ? 2 : 1);
771 
772 	usb_serial_debug_data(dev, __func__, port->interrupt_out_size,
773 			      port->interrupt_out_urb->transfer_buffer);
774 
775 	usb_fill_int_urb(port->interrupt_out_urb, port->serial->dev,
776 		usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
777 		port->interrupt_out_buffer, port->interrupt_out_size,
778 		cypress_write_int_callback, port, priv->write_urb_interval);
779 	result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
780 	if (result) {
781 		dev_err_console(port,
782 				"%s - failed submitting write urb, error %d\n",
783 							__func__, result);
784 		priv->write_urb_in_use = 0;
785 		cypress_set_dead(port);
786 	}
787 
788 	spin_lock_irqsave(&priv->lock, flags);
789 	if (priv->cmd_ctrl)
790 		priv->cmd_ctrl = 0;
791 
792 	/* do not count the line control and size bytes */
793 	priv->bytes_out += count;
794 	spin_unlock_irqrestore(&priv->lock, flags);
795 
796 	usb_serial_port_softint(port);
797 } /* cypress_send */
798 
799 
800 /* returns how much space is available in the soft buffer */
801 static int cypress_write_room(struct tty_struct *tty)
802 {
803 	struct usb_serial_port *port = tty->driver_data;
804 	struct cypress_private *priv = usb_get_serial_port_data(port);
805 	int room = 0;
806 	unsigned long flags;
807 
808 	spin_lock_irqsave(&priv->lock, flags);
809 	room = kfifo_avail(&priv->write_fifo);
810 	spin_unlock_irqrestore(&priv->lock, flags);
811 
812 	dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
813 	return room;
814 }
815 
816 
817 static int cypress_tiocmget(struct tty_struct *tty)
818 {
819 	struct usb_serial_port *port = tty->driver_data;
820 	struct cypress_private *priv = usb_get_serial_port_data(port);
821 	__u8 status, control;
822 	unsigned int result = 0;
823 	unsigned long flags;
824 
825 	spin_lock_irqsave(&priv->lock, flags);
826 	control = priv->line_control;
827 	status = priv->current_status;
828 	spin_unlock_irqrestore(&priv->lock, flags);
829 
830 	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
831 		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
832 		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
833 		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
834 		| ((status & UART_RI)         ? TIOCM_RI  : 0)
835 		| ((status & UART_CD)         ? TIOCM_CD  : 0);
836 
837 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
838 
839 	return result;
840 }
841 
842 
843 static int cypress_tiocmset(struct tty_struct *tty,
844 			       unsigned int set, unsigned int clear)
845 {
846 	struct usb_serial_port *port = tty->driver_data;
847 	struct cypress_private *priv = usb_get_serial_port_data(port);
848 	unsigned long flags;
849 
850 	spin_lock_irqsave(&priv->lock, flags);
851 	if (set & TIOCM_RTS)
852 		priv->line_control |= CONTROL_RTS;
853 	if (set & TIOCM_DTR)
854 		priv->line_control |= CONTROL_DTR;
855 	if (clear & TIOCM_RTS)
856 		priv->line_control &= ~CONTROL_RTS;
857 	if (clear & TIOCM_DTR)
858 		priv->line_control &= ~CONTROL_DTR;
859 	priv->cmd_ctrl = 1;
860 	spin_unlock_irqrestore(&priv->lock, flags);
861 
862 	return cypress_write(tty, port, NULL, 0);
863 }
864 
865 static void cypress_set_termios(struct tty_struct *tty,
866 	struct usb_serial_port *port, struct ktermios *old_termios)
867 {
868 	struct cypress_private *priv = usb_get_serial_port_data(port);
869 	struct device *dev = &port->dev;
870 	int data_bits, stop_bits, parity_type, parity_enable;
871 	unsigned cflag, iflag;
872 	unsigned long flags;
873 	__u8 oldlines;
874 	int linechange = 0;
875 
876 	spin_lock_irqsave(&priv->lock, flags);
877 	/* We can't clean this one up as we don't know the device type
878 	   early enough */
879 	if (!priv->termios_initialized) {
880 		if (priv->chiptype == CT_EARTHMATE) {
881 			tty->termios = tty_std_termios;
882 			tty->termios.c_cflag = B4800 | CS8 | CREAD | HUPCL |
883 				CLOCAL;
884 			tty->termios.c_ispeed = 4800;
885 			tty->termios.c_ospeed = 4800;
886 		} else if (priv->chiptype == CT_CYPHIDCOM) {
887 			tty->termios = tty_std_termios;
888 			tty->termios.c_cflag = B9600 | CS8 | CREAD | HUPCL |
889 				CLOCAL;
890 			tty->termios.c_ispeed = 9600;
891 			tty->termios.c_ospeed = 9600;
892 		} else if (priv->chiptype == CT_CA42V2) {
893 			tty->termios = tty_std_termios;
894 			tty->termios.c_cflag = B9600 | CS8 | CREAD | HUPCL |
895 				CLOCAL;
896 			tty->termios.c_ispeed = 9600;
897 			tty->termios.c_ospeed = 9600;
898 		}
899 		priv->termios_initialized = 1;
900 	}
901 	spin_unlock_irqrestore(&priv->lock, flags);
902 
903 	/* Unsupported features need clearing */
904 	tty->termios.c_cflag &= ~(CMSPAR|CRTSCTS);
905 
906 	cflag = tty->termios.c_cflag;
907 	iflag = tty->termios.c_iflag;
908 
909 	/* check if there are new settings */
910 	if (old_termios) {
911 		spin_lock_irqsave(&priv->lock, flags);
912 		priv->tmp_termios = tty->termios;
913 		spin_unlock_irqrestore(&priv->lock, flags);
914 	}
915 
916 	/* set number of data bits, parity, stop bits */
917 	/* when parity is disabled the parity type bit is ignored */
918 
919 	/* 1 means 2 stop bits, 0 means 1 stop bit */
920 	stop_bits = cflag & CSTOPB ? 1 : 0;
921 
922 	if (cflag & PARENB) {
923 		parity_enable = 1;
924 		/* 1 means odd parity, 0 means even parity */
925 		parity_type = cflag & PARODD ? 1 : 0;
926 	} else
927 		parity_enable = parity_type = 0;
928 
929 	switch (cflag & CSIZE) {
930 	case CS5:
931 		data_bits = 0;
932 		break;
933 	case CS6:
934 		data_bits = 1;
935 		break;
936 	case CS7:
937 		data_bits = 2;
938 		break;
939 	case CS8:
940 		data_bits = 3;
941 		break;
942 	default:
943 		dev_err(dev, "%s - CSIZE was set, but not CS5-CS8\n", __func__);
944 		data_bits = 3;
945 	}
946 	spin_lock_irqsave(&priv->lock, flags);
947 	oldlines = priv->line_control;
948 	if ((cflag & CBAUD) == B0) {
949 		/* drop dtr and rts */
950 		dev_dbg(dev, "%s - dropping the lines, baud rate 0bps\n", __func__);
951 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
952 	} else
953 		priv->line_control = (CONTROL_DTR | CONTROL_RTS);
954 	spin_unlock_irqrestore(&priv->lock, flags);
955 
956 	dev_dbg(dev, "%s - sending %d stop_bits, %d parity_enable, %d parity_type, %d data_bits (+5)\n",
957 		__func__, stop_bits, parity_enable, parity_type, data_bits);
958 
959 	cypress_serial_control(tty, port, tty_get_baud_rate(tty),
960 			data_bits, stop_bits,
961 			parity_enable, parity_type,
962 			0, CYPRESS_SET_CONFIG);
963 
964 	/* we perform a CYPRESS_GET_CONFIG so that the current settings are
965 	 * filled into the private structure this should confirm that all is
966 	 * working if it returns what we just set */
967 	cypress_serial_control(tty, port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
968 
969 	/* Here we can define custom tty settings for devices; the main tty
970 	 * termios flag base comes from empeg.c */
971 
972 	spin_lock_irqsave(&priv->lock, flags);
973 	if (priv->chiptype == CT_EARTHMATE && priv->baud_rate == 4800) {
974 		dev_dbg(dev, "Using custom termios settings for a baud rate of 4800bps.\n");
975 		/* define custom termios settings for NMEA protocol */
976 
977 		tty->termios.c_iflag /* input modes - */
978 			&= ~(IGNBRK  /* disable ignore break */
979 			| BRKINT     /* disable break causes interrupt */
980 			| PARMRK     /* disable mark parity errors */
981 			| ISTRIP     /* disable clear high bit of input char */
982 			| INLCR      /* disable translate NL to CR */
983 			| IGNCR      /* disable ignore CR */
984 			| ICRNL      /* disable translate CR to NL */
985 			| IXON);     /* disable enable XON/XOFF flow control */
986 
987 		tty->termios.c_oflag /* output modes */
988 			&= ~OPOST;    /* disable postprocess output char */
989 
990 		tty->termios.c_lflag /* line discipline modes */
991 			&= ~(ECHO     /* disable echo input characters */
992 			| ECHONL      /* disable echo new line */
993 			| ICANON      /* disable erase, kill, werase, and rprnt
994 					 special characters */
995 			| ISIG        /* disable interrupt, quit, and suspend
996 					 special characters */
997 			| IEXTEN);    /* disable non-POSIX special characters */
998 	} /* CT_CYPHIDCOM: Application should handle this for device */
999 
1000 	linechange = (priv->line_control != oldlines);
1001 	spin_unlock_irqrestore(&priv->lock, flags);
1002 
1003 	/* if necessary, set lines */
1004 	if (linechange) {
1005 		priv->cmd_ctrl = 1;
1006 		cypress_write(tty, port, NULL, 0);
1007 	}
1008 } /* cypress_set_termios */
1009 
1010 
1011 /* returns amount of data still left in soft buffer */
1012 static int cypress_chars_in_buffer(struct tty_struct *tty)
1013 {
1014 	struct usb_serial_port *port = tty->driver_data;
1015 	struct cypress_private *priv = usb_get_serial_port_data(port);
1016 	int chars = 0;
1017 	unsigned long flags;
1018 
1019 	spin_lock_irqsave(&priv->lock, flags);
1020 	chars = kfifo_len(&priv->write_fifo);
1021 	spin_unlock_irqrestore(&priv->lock, flags);
1022 
1023 	dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars);
1024 	return chars;
1025 }
1026 
1027 
1028 static void cypress_throttle(struct tty_struct *tty)
1029 {
1030 	struct usb_serial_port *port = tty->driver_data;
1031 	struct cypress_private *priv = usb_get_serial_port_data(port);
1032 
1033 	spin_lock_irq(&priv->lock);
1034 	priv->rx_flags = THROTTLED;
1035 	spin_unlock_irq(&priv->lock);
1036 }
1037 
1038 
1039 static void cypress_unthrottle(struct tty_struct *tty)
1040 {
1041 	struct usb_serial_port *port = tty->driver_data;
1042 	struct cypress_private *priv = usb_get_serial_port_data(port);
1043 	int actually_throttled, result;
1044 
1045 	spin_lock_irq(&priv->lock);
1046 	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
1047 	priv->rx_flags = 0;
1048 	spin_unlock_irq(&priv->lock);
1049 
1050 	if (!priv->comm_is_ok)
1051 		return;
1052 
1053 	if (actually_throttled) {
1054 		result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
1055 		if (result) {
1056 			dev_err(&port->dev, "%s - failed submitting read urb, "
1057 					"error %d\n", __func__, result);
1058 			cypress_set_dead(port);
1059 		}
1060 	}
1061 }
1062 
1063 
1064 static void cypress_read_int_callback(struct urb *urb)
1065 {
1066 	struct usb_serial_port *port = urb->context;
1067 	struct cypress_private *priv = usb_get_serial_port_data(port);
1068 	struct device *dev = &urb->dev->dev;
1069 	struct tty_struct *tty;
1070 	unsigned char *data = urb->transfer_buffer;
1071 	unsigned long flags;
1072 	char tty_flag = TTY_NORMAL;
1073 	int havedata = 0;
1074 	int bytes = 0;
1075 	int result;
1076 	int i = 0;
1077 	int status = urb->status;
1078 
1079 	switch (status) {
1080 	case 0: /* success */
1081 		break;
1082 	case -ECONNRESET:
1083 	case -ENOENT:
1084 	case -ESHUTDOWN:
1085 		/* precursor to disconnect so just go away */
1086 		return;
1087 	case -EPIPE:
1088 		/* Can't call usb_clear_halt while in_interrupt */
1089 		/* FALLS THROUGH */
1090 	default:
1091 		/* something ugly is going on... */
1092 		dev_err(dev, "%s - unexpected nonzero read status received: %d\n",
1093 			__func__, status);
1094 		cypress_set_dead(port);
1095 		return;
1096 	}
1097 
1098 	spin_lock_irqsave(&priv->lock, flags);
1099 	if (priv->rx_flags & THROTTLED) {
1100 		dev_dbg(dev, "%s - now throttling\n", __func__);
1101 		priv->rx_flags |= ACTUALLY_THROTTLED;
1102 		spin_unlock_irqrestore(&priv->lock, flags);
1103 		return;
1104 	}
1105 	spin_unlock_irqrestore(&priv->lock, flags);
1106 
1107 	tty = tty_port_tty_get(&port->port);
1108 	if (!tty) {
1109 		dev_dbg(dev, "%s - bad tty pointer - exiting\n", __func__);
1110 		return;
1111 	}
1112 
1113 	spin_lock_irqsave(&priv->lock, flags);
1114 	result = urb->actual_length;
1115 	switch (priv->pkt_fmt) {
1116 	default:
1117 	case packet_format_1:
1118 		/* This is for the CY7C64013... */
1119 		priv->current_status = data[0] & 0xF8;
1120 		bytes = data[1] + 2;
1121 		i = 2;
1122 		if (bytes > 2)
1123 			havedata = 1;
1124 		break;
1125 	case packet_format_2:
1126 		/* This is for the CY7C63743... */
1127 		priv->current_status = data[0] & 0xF8;
1128 		bytes = (data[0] & 0x07) + 1;
1129 		i = 1;
1130 		if (bytes > 1)
1131 			havedata = 1;
1132 		break;
1133 	}
1134 	spin_unlock_irqrestore(&priv->lock, flags);
1135 	if (result < bytes) {
1136 		dev_dbg(dev,
1137 			"%s - wrong packet size - received %d bytes but packet said %d bytes\n",
1138 			__func__, result, bytes);
1139 		goto continue_read;
1140 	}
1141 
1142 	usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
1143 
1144 	spin_lock_irqsave(&priv->lock, flags);
1145 	/* check to see if status has changed */
1146 	if (priv->current_status != priv->prev_status) {
1147 		u8 delta = priv->current_status ^ priv->prev_status;
1148 
1149 		if (delta & UART_MSR_MASK) {
1150 			if (delta & UART_CTS)
1151 				port->icount.cts++;
1152 			if (delta & UART_DSR)
1153 				port->icount.dsr++;
1154 			if (delta & UART_RI)
1155 				port->icount.rng++;
1156 			if (delta & UART_CD)
1157 				port->icount.dcd++;
1158 
1159 			wake_up_interruptible(&port->port.delta_msr_wait);
1160 		}
1161 
1162 		priv->prev_status = priv->current_status;
1163 	}
1164 	spin_unlock_irqrestore(&priv->lock, flags);
1165 
1166 	/* hangup, as defined in acm.c... this might be a bad place for it
1167 	 * though */
1168 	if (tty && !(tty->termios.c_cflag & CLOCAL) &&
1169 			!(priv->current_status & UART_CD)) {
1170 		dev_dbg(dev, "%s - calling hangup\n", __func__);
1171 		tty_hangup(tty);
1172 		goto continue_read;
1173 	}
1174 
1175 	/* There is one error bit... I'm assuming it is a parity error
1176 	 * indicator as the generic firmware will set this bit to 1 if a
1177 	 * parity error occurs.
1178 	 * I can not find reference to any other error events. */
1179 	spin_lock_irqsave(&priv->lock, flags);
1180 	if (priv->current_status & CYP_ERROR) {
1181 		spin_unlock_irqrestore(&priv->lock, flags);
1182 		tty_flag = TTY_PARITY;
1183 		dev_dbg(dev, "%s - Parity Error detected\n", __func__);
1184 	} else
1185 		spin_unlock_irqrestore(&priv->lock, flags);
1186 
1187 	/* process read if there is data other than line status */
1188 	if (bytes > i) {
1189 		tty_insert_flip_string_fixed_flag(&port->port, data + i,
1190 				tty_flag, bytes - i);
1191 		tty_flip_buffer_push(&port->port);
1192 	}
1193 
1194 	spin_lock_irqsave(&priv->lock, flags);
1195 	/* control and status byte(s) are also counted */
1196 	priv->bytes_in += bytes;
1197 	spin_unlock_irqrestore(&priv->lock, flags);
1198 
1199 continue_read:
1200 	tty_kref_put(tty);
1201 
1202 	/* Continue trying to always read */
1203 
1204 	if (priv->comm_is_ok) {
1205 		usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1206 				usb_rcvintpipe(port->serial->dev,
1207 					port->interrupt_in_endpointAddress),
1208 				port->interrupt_in_urb->transfer_buffer,
1209 				port->interrupt_in_urb->transfer_buffer_length,
1210 				cypress_read_int_callback, port,
1211 				priv->read_urb_interval);
1212 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1213 		if (result && result != -EPERM) {
1214 			dev_err(dev, "%s - failed resubmitting read urb, error %d\n",
1215 				__func__, result);
1216 			cypress_set_dead(port);
1217 		}
1218 	}
1219 } /* cypress_read_int_callback */
1220 
1221 
1222 static void cypress_write_int_callback(struct urb *urb)
1223 {
1224 	struct usb_serial_port *port = urb->context;
1225 	struct cypress_private *priv = usb_get_serial_port_data(port);
1226 	struct device *dev = &urb->dev->dev;
1227 	int status = urb->status;
1228 
1229 	switch (status) {
1230 	case 0:
1231 		/* success */
1232 		break;
1233 	case -ECONNRESET:
1234 	case -ENOENT:
1235 	case -ESHUTDOWN:
1236 		/* this urb is terminated, clean up */
1237 		dev_dbg(dev, "%s - urb shutting down with status: %d\n",
1238 			__func__, status);
1239 		priv->write_urb_in_use = 0;
1240 		return;
1241 	case -EPIPE:
1242 		/* Cannot call usb_clear_halt while in_interrupt */
1243 		/* FALLTHROUGH */
1244 	default:
1245 		dev_err(dev, "%s - unexpected nonzero write status received: %d\n",
1246 			__func__, status);
1247 		cypress_set_dead(port);
1248 		break;
1249 	}
1250 	priv->write_urb_in_use = 0;
1251 
1252 	/* send any buffered data */
1253 	cypress_send(port);
1254 }
1255 
1256 module_usb_serial_driver(serial_drivers, id_table_combined);
1257 
1258 MODULE_AUTHOR(DRIVER_AUTHOR);
1259 MODULE_DESCRIPTION(DRIVER_DESC);
1260 MODULE_LICENSE("GPL");
1261 
1262 module_param(stats, bool, S_IRUGO | S_IWUSR);
1263 MODULE_PARM_DESC(stats, "Enable statistics or not");
1264 module_param(interval, int, S_IRUGO | S_IWUSR);
1265 MODULE_PARM_DESC(interval, "Overrides interrupt interval");
1266 module_param(unstable_bauds, bool, S_IRUGO | S_IWUSR);
1267 MODULE_PARM_DESC(unstable_bauds, "Allow unstable baud rates");
1268