xref: /linux/drivers/usb/serial/cypress_m8.c (revision f9c41a62bba3f3f7ef3541b2a025e3371bcbba97)
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 stats;
50 static int interval;
51 static bool unstable_bauds;
52 
53 #define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
54 #define DRIVER_DESC "Cypress USB to Serial Driver"
55 
56 /* write buffer size defines */
57 #define CYPRESS_BUF_SIZE	1024
58 
59 static const struct usb_device_id id_table_earthmate[] = {
60 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
61 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
62 	{ }						/* Terminating entry */
63 };
64 
65 static const struct usb_device_id id_table_cyphidcomrs232[] = {
66 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
67 	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
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_DAZZLE, PRODUCT_ID_CA42) },
82 	{ }						/* Terminating entry */
83 };
84 
85 MODULE_DEVICE_TABLE(usb, id_table_combined);
86 
87 enum packet_format {
88 	packet_format_1,  /* b0:status, b1:payload count */
89 	packet_format_2   /* b0[7:3]:status, b0[2:0]:payload count */
90 };
91 
92 struct cypress_private {
93 	spinlock_t lock;		   /* private lock */
94 	int chiptype;			   /* identifier of device, for quirks/etc */
95 	int bytes_in;			   /* used for statistics */
96 	int bytes_out;			   /* used for statistics */
97 	int cmd_count;			   /* used for statistics */
98 	int cmd_ctrl;			   /* always set this to 1 before issuing a command */
99 	struct kfifo write_fifo;	   /* write fifo */
100 	int write_urb_in_use;		   /* write urb in use indicator */
101 	int write_urb_interval;            /* interval to use for write urb */
102 	int read_urb_interval;             /* interval to use for read urb */
103 	int comm_is_ok;                    /* true if communication is (still) ok */
104 	int termios_initialized;
105 	__u8 line_control;	   	   /* holds dtr / rts value */
106 	__u8 current_status;	   	   /* received from last read - info on dsr,cts,cd,ri,etc */
107 	__u8 current_config;	   	   /* stores the current configuration byte */
108 	__u8 rx_flags;			   /* throttling - used from whiteheat/ftdi_sio */
109 	enum packet_format pkt_fmt;	   /* format to use for packet send / receive */
110 	int get_cfg_unsafe;		   /* If true, the CYPRESS_GET_CONFIG is unsafe */
111 	int baud_rate;			   /* stores current baud rate in
112 					      integer form */
113 	int isthrottled;		   /* if throttled, discard reads */
114 	char prev_status, diff_status;	   /* used for TIOCMIWAIT */
115 	/* we pass a pointer to this as the argument sent to
116 	   cypress_set_termios old_termios */
117 	struct ktermios tmp_termios; 	   /* stores the old termios settings */
118 };
119 
120 /* function prototypes for the Cypress USB to serial device */
121 static int  cypress_earthmate_port_probe(struct usb_serial_port *port);
122 static int  cypress_hidcom_port_probe(struct usb_serial_port *port);
123 static int  cypress_ca42v2_port_probe(struct usb_serial_port *port);
124 static int  cypress_port_remove(struct usb_serial_port *port);
125 static int  cypress_open(struct tty_struct *tty, struct usb_serial_port *port);
126 static void cypress_close(struct usb_serial_port *port);
127 static void cypress_dtr_rts(struct usb_serial_port *port, int on);
128 static int  cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
129 			const unsigned char *buf, int count);
130 static void cypress_send(struct usb_serial_port *port);
131 static int  cypress_write_room(struct tty_struct *tty);
132 static int  cypress_ioctl(struct tty_struct *tty,
133 			unsigned int cmd, unsigned long arg);
134 static void cypress_set_termios(struct tty_struct *tty,
135 			struct usb_serial_port *port, struct ktermios *old);
136 static int  cypress_tiocmget(struct tty_struct *tty);
137 static int  cypress_tiocmset(struct tty_struct *tty,
138 			unsigned int set, unsigned int clear);
139 static int  cypress_chars_in_buffer(struct tty_struct *tty);
140 static void cypress_throttle(struct tty_struct *tty);
141 static void cypress_unthrottle(struct tty_struct *tty);
142 static void cypress_set_dead(struct usb_serial_port *port);
143 static void cypress_read_int_callback(struct urb *urb);
144 static void cypress_write_int_callback(struct urb *urb);
145 
146 static struct usb_serial_driver cypress_earthmate_device = {
147 	.driver = {
148 		.owner =		THIS_MODULE,
149 		.name =			"earthmate",
150 	},
151 	.description =			"DeLorme Earthmate USB",
152 	.id_table =			id_table_earthmate,
153 	.num_ports =			1,
154 	.port_probe =			cypress_earthmate_port_probe,
155 	.port_remove =			cypress_port_remove,
156 	.open =				cypress_open,
157 	.close =			cypress_close,
158 	.dtr_rts =			cypress_dtr_rts,
159 	.write =			cypress_write,
160 	.write_room =			cypress_write_room,
161 	.ioctl =			cypress_ioctl,
162 	.set_termios =			cypress_set_termios,
163 	.tiocmget =			cypress_tiocmget,
164 	.tiocmset =			cypress_tiocmset,
165 	.chars_in_buffer =		cypress_chars_in_buffer,
166 	.throttle =		 	cypress_throttle,
167 	.unthrottle =			cypress_unthrottle,
168 	.read_int_callback =		cypress_read_int_callback,
169 	.write_int_callback =		cypress_write_int_callback,
170 };
171 
172 static struct usb_serial_driver cypress_hidcom_device = {
173 	.driver = {
174 		.owner =		THIS_MODULE,
175 		.name =			"cyphidcom",
176 	},
177 	.description =			"HID->COM RS232 Adapter",
178 	.id_table =			id_table_cyphidcomrs232,
179 	.num_ports =			1,
180 	.port_probe =			cypress_hidcom_port_probe,
181 	.port_remove =			cypress_port_remove,
182 	.open =				cypress_open,
183 	.close =			cypress_close,
184 	.dtr_rts =			cypress_dtr_rts,
185 	.write =			cypress_write,
186 	.write_room =			cypress_write_room,
187 	.ioctl =			cypress_ioctl,
188 	.set_termios =			cypress_set_termios,
189 	.tiocmget =			cypress_tiocmget,
190 	.tiocmset =			cypress_tiocmset,
191 	.chars_in_buffer =		cypress_chars_in_buffer,
192 	.throttle =			cypress_throttle,
193 	.unthrottle =			cypress_unthrottle,
194 	.read_int_callback =		cypress_read_int_callback,
195 	.write_int_callback =		cypress_write_int_callback,
196 };
197 
198 static struct usb_serial_driver cypress_ca42v2_device = {
199 	.driver = {
200 		.owner =		THIS_MODULE,
201 		.name =			"nokiaca42v2",
202 	},
203 	.description =			"Nokia CA-42 V2 Adapter",
204 	.id_table =			id_table_nokiaca42v2,
205 	.num_ports =			1,
206 	.port_probe =			cypress_ca42v2_port_probe,
207 	.port_remove =			cypress_port_remove,
208 	.open =				cypress_open,
209 	.close =			cypress_close,
210 	.dtr_rts =			cypress_dtr_rts,
211 	.write =			cypress_write,
212 	.write_room =			cypress_write_room,
213 	.ioctl =			cypress_ioctl,
214 	.set_termios =			cypress_set_termios,
215 	.tiocmget =			cypress_tiocmget,
216 	.tiocmset =			cypress_tiocmset,
217 	.chars_in_buffer =		cypress_chars_in_buffer,
218 	.throttle =			cypress_throttle,
219 	.unthrottle =			cypress_unthrottle,
220 	.read_int_callback =		cypress_read_int_callback,
221 	.write_int_callback =		cypress_write_int_callback,
222 };
223 
224 static struct usb_serial_driver * const serial_drivers[] = {
225 	&cypress_earthmate_device, &cypress_hidcom_device,
226 	&cypress_ca42v2_device, NULL
227 };
228 
229 /*****************************************************************************
230  * Cypress serial helper functions
231  *****************************************************************************/
232 
233 
234 static int analyze_baud_rate(struct usb_serial_port *port, speed_t new_rate)
235 {
236 	struct cypress_private *priv;
237 	priv = usb_get_serial_port_data(port);
238 
239 	if (unstable_bauds)
240 		return new_rate;
241 
242 	/*
243 	 * The general purpose firmware for the Cypress M8 allows for
244 	 * a maximum speed of 57600bps (I have no idea whether DeLorme
245 	 * chose to use the general purpose firmware or not), if you
246 	 * need to modify this speed setting for your own project
247 	 * please add your own chiptype and modify the code likewise.
248 	 * The Cypress HID->COM device will work successfully up to
249 	 * 115200bps (but the actual throughput is around 3kBps).
250 	 */
251 	if (port->serial->dev->speed == USB_SPEED_LOW) {
252 		/*
253 		 * Mike Isely <isely@pobox.com> 2-Feb-2008: The
254 		 * Cypress app note that describes this mechanism
255 		 * states the the low-speed part can't handle more
256 		 * than 800 bytes/sec, in which case 4800 baud is the
257 		 * safest speed for a part like that.
258 		 */
259 		if (new_rate > 4800) {
260 			dev_dbg(&port->dev,
261 				"%s - failed setting baud rate, device incapable speed %d\n",
262 				__func__, new_rate);
263 			return -1;
264 		}
265 	}
266 	switch (priv->chiptype) {
267 	case CT_EARTHMATE:
268 		if (new_rate <= 600) {
269 			/* 300 and 600 baud rates are supported under
270 			 * the generic firmware, but are not used with
271 			 * NMEA and SiRF protocols */
272 			dev_dbg(&port->dev,
273 				"%s - failed setting baud rate, unsupported speed of %d on Earthmate GPS",
274 				__func__, new_rate);
275 			return -1;
276 		}
277 		break;
278 	default:
279 		break;
280 	}
281 	return new_rate;
282 }
283 
284 
285 /* This function can either set or retrieve the current serial line settings */
286 static int cypress_serial_control(struct tty_struct *tty,
287 	struct usb_serial_port *port, speed_t baud_rate, int data_bits,
288 	int stop_bits, int parity_enable, int parity_type, int reset,
289 	int cypress_request_type)
290 {
291 	int new_baudrate = 0, retval = 0, tries = 0;
292 	struct cypress_private *priv;
293 	struct device *dev = &port->dev;
294 	u8 *feature_buffer;
295 	const unsigned int feature_len = 5;
296 	unsigned long flags;
297 
298 	priv = usb_get_serial_port_data(port);
299 
300 	if (!priv->comm_is_ok)
301 		return -ENODEV;
302 
303 	feature_buffer = kcalloc(feature_len, sizeof(u8), GFP_KERNEL);
304 	if (!feature_buffer)
305 		return -ENOMEM;
306 
307 	switch (cypress_request_type) {
308 	case CYPRESS_SET_CONFIG:
309 		/* 0 means 'Hang up' so doesn't change the true bit rate */
310 		new_baudrate = priv->baud_rate;
311 		if (baud_rate && baud_rate != priv->baud_rate) {
312 			dev_dbg(dev, "%s - baud rate is changing\n", __func__);
313 			retval = analyze_baud_rate(port, baud_rate);
314 			if (retval >= 0) {
315 				new_baudrate = retval;
316 				dev_dbg(dev, "%s - New baud rate set to %d\n",
317 					__func__, new_baudrate);
318 			}
319 		}
320 		dev_dbg(dev, "%s - baud rate is being sent as %d\n", __func__,
321 			new_baudrate);
322 
323 		/* fill the feature_buffer with new configuration */
324 		put_unaligned_le32(new_baudrate, feature_buffer);
325 		feature_buffer[4] |= data_bits;   /* assign data bits in 2 bit space ( max 3 ) */
326 		/* 1 bit gap */
327 		feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
328 		feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
329 		feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
330 		/* 1 bit gap */
331 		feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
332 
333 		dev_dbg(dev, "%s - device is being sent this feature report:\n", __func__);
334 		dev_dbg(dev, "%s - %02X - %02X - %02X - %02X - %02X\n", __func__,
335 			feature_buffer[0], feature_buffer[1],
336 			feature_buffer[2], feature_buffer[3],
337 			feature_buffer[4]);
338 
339 		do {
340 			retval = usb_control_msg(port->serial->dev,
341 					usb_sndctrlpipe(port->serial->dev, 0),
342 					HID_REQ_SET_REPORT,
343 					USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
344 					0x0300, 0, feature_buffer,
345 					feature_len, 500);
346 
347 			if (tries++ >= 3)
348 				break;
349 
350 		} while (retval != feature_len &&
351 			 retval != -ENODEV);
352 
353 		if (retval != feature_len) {
354 			dev_err(dev, "%s - failed sending serial line settings - %d\n",
355 				__func__, retval);
356 			cypress_set_dead(port);
357 		} else {
358 			spin_lock_irqsave(&priv->lock, flags);
359 			priv->baud_rate = new_baudrate;
360 			priv->current_config = feature_buffer[4];
361 			spin_unlock_irqrestore(&priv->lock, flags);
362 			/* If we asked for a speed change encode it */
363 			if (baud_rate)
364 				tty_encode_baud_rate(tty,
365 					new_baudrate, new_baudrate);
366 		}
367 	break;
368 	case CYPRESS_GET_CONFIG:
369 		if (priv->get_cfg_unsafe) {
370 			/* Not implemented for this device,
371 			   and if we try to do it we're likely
372 			   to crash the hardware. */
373 			retval = -ENOTTY;
374 			goto out;
375 		}
376 		dev_dbg(dev, "%s - retreiving serial line settings\n", __func__);
377 		do {
378 			retval = usb_control_msg(port->serial->dev,
379 					usb_rcvctrlpipe(port->serial->dev, 0),
380 					HID_REQ_GET_REPORT,
381 					USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
382 					0x0300, 0, feature_buffer,
383 					feature_len, 500);
384 
385 			if (tries++ >= 3)
386 				break;
387 		} while (retval != feature_len
388 						&& retval != -ENODEV);
389 
390 		if (retval != feature_len) {
391 			dev_err(dev, "%s - failed to retrieve serial line settings - %d\n",
392 				__func__, retval);
393 			cypress_set_dead(port);
394 			goto out;
395 		} else {
396 			spin_lock_irqsave(&priv->lock, flags);
397 			/* store the config in one byte, and later
398 			   use bit masks to check values */
399 			priv->current_config = feature_buffer[4];
400 			priv->baud_rate = get_unaligned_le32(feature_buffer);
401 			spin_unlock_irqrestore(&priv->lock, flags);
402 		}
403 	}
404 	spin_lock_irqsave(&priv->lock, flags);
405 	++priv->cmd_count;
406 	spin_unlock_irqrestore(&priv->lock, flags);
407 out:
408 	kfree(feature_buffer);
409 	return retval;
410 } /* cypress_serial_control */
411 
412 
413 static void cypress_set_dead(struct usb_serial_port *port)
414 {
415 	struct cypress_private *priv = usb_get_serial_port_data(port);
416 	unsigned long flags;
417 
418 	spin_lock_irqsave(&priv->lock, flags);
419 	if (!priv->comm_is_ok) {
420 		spin_unlock_irqrestore(&priv->lock, flags);
421 		return;
422 	}
423 	priv->comm_is_ok = 0;
424 	spin_unlock_irqrestore(&priv->lock, flags);
425 
426 	dev_err(&port->dev, "cypress_m8 suspending failing port %d - "
427 		"interval might be too short\n", port->number);
428 }
429 
430 
431 /*****************************************************************************
432  * Cypress serial driver functions
433  *****************************************************************************/
434 
435 
436 static int cypress_generic_port_probe(struct usb_serial_port *port)
437 {
438 	struct usb_serial *serial = port->serial;
439 	struct cypress_private *priv;
440 
441 	priv = kzalloc(sizeof(struct cypress_private), GFP_KERNEL);
442 	if (!priv)
443 		return -ENOMEM;
444 
445 	priv->comm_is_ok = !0;
446 	spin_lock_init(&priv->lock);
447 	if (kfifo_alloc(&priv->write_fifo, CYPRESS_BUF_SIZE, GFP_KERNEL)) {
448 		kfree(priv);
449 		return -ENOMEM;
450 	}
451 
452 	usb_reset_configuration(serial->dev);
453 
454 	priv->cmd_ctrl = 0;
455 	priv->line_control = 0;
456 	priv->termios_initialized = 0;
457 	priv->rx_flags = 0;
458 	/* Default packet format setting is determined by packet size.
459 	   Anything with a size larger then 9 must have a separate
460 	   count field since the 3 bit count field is otherwise too
461 	   small.  Otherwise we can use the slightly more compact
462 	   format.  This is in accordance with the cypress_m8 serial
463 	   converter app note. */
464 	if (port->interrupt_out_size > 9)
465 		priv->pkt_fmt = packet_format_1;
466 	else
467 		priv->pkt_fmt = packet_format_2;
468 
469 	if (interval > 0) {
470 		priv->write_urb_interval = interval;
471 		priv->read_urb_interval = interval;
472 		dev_dbg(&port->dev, "%s - read & write intervals forced to %d\n",
473 			__func__, interval);
474 	} else {
475 		priv->write_urb_interval = port->interrupt_out_urb->interval;
476 		priv->read_urb_interval = port->interrupt_in_urb->interval;
477 		dev_dbg(&port->dev, "%s - intervals: read=%d write=%d\n",
478 			__func__, priv->read_urb_interval,
479 			priv->write_urb_interval);
480 	}
481 	usb_set_serial_port_data(port, priv);
482 
483 	return 0;
484 }
485 
486 
487 static int cypress_earthmate_port_probe(struct usb_serial_port *port)
488 {
489 	struct usb_serial *serial = port->serial;
490 	struct cypress_private *priv;
491 	int ret;
492 
493 	ret = cypress_generic_port_probe(port);
494 	if (ret) {
495 		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
496 		return ret;
497 	}
498 
499 	priv = usb_get_serial_port_data(port);
500 	priv->chiptype = CT_EARTHMATE;
501 	/* All Earthmate devices use the separated-count packet
502 	   format!  Idiotic. */
503 	priv->pkt_fmt = packet_format_1;
504 	if (serial->dev->descriptor.idProduct !=
505 				cpu_to_le16(PRODUCT_ID_EARTHMATEUSB)) {
506 		/* The old original USB Earthmate seemed able to
507 		   handle GET_CONFIG requests; everything they've
508 		   produced since that time crashes if this command is
509 		   attempted :-( */
510 		dev_dbg(&port->dev,
511 			"%s - Marking this device as unsafe for GET_CONFIG commands\n",
512 			__func__);
513 		priv->get_cfg_unsafe = !0;
514 	}
515 
516 	return 0;
517 }
518 
519 static int cypress_hidcom_port_probe(struct usb_serial_port *port)
520 {
521 	struct cypress_private *priv;
522 	int ret;
523 
524 	ret = cypress_generic_port_probe(port);
525 	if (ret) {
526 		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
527 		return ret;
528 	}
529 
530 	priv = usb_get_serial_port_data(port);
531 	priv->chiptype = CT_CYPHIDCOM;
532 
533 	return 0;
534 }
535 
536 static int cypress_ca42v2_port_probe(struct usb_serial_port *port)
537 {
538 	struct cypress_private *priv;
539 	int ret;
540 
541 	ret = cypress_generic_port_probe(port);
542 	if (ret) {
543 		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
544 		return ret;
545 	}
546 
547 	priv = usb_get_serial_port_data(port);
548 	priv->chiptype = CT_CA42V2;
549 
550 	return 0;
551 }
552 
553 static int cypress_port_remove(struct usb_serial_port *port)
554 {
555 	struct cypress_private *priv;
556 
557 	priv = usb_get_serial_port_data(port);
558 
559 	kfifo_free(&priv->write_fifo);
560 	kfree(priv);
561 
562 	return 0;
563 }
564 
565 static int cypress_open(struct tty_struct *tty, struct usb_serial_port *port)
566 {
567 	struct cypress_private *priv = usb_get_serial_port_data(port);
568 	struct usb_serial *serial = port->serial;
569 	unsigned long flags;
570 	int result = 0;
571 
572 	if (!priv->comm_is_ok)
573 		return -EIO;
574 
575 	/* clear halts before open */
576 	usb_clear_halt(serial->dev, 0x81);
577 	usb_clear_halt(serial->dev, 0x02);
578 
579 	spin_lock_irqsave(&priv->lock, flags);
580 	/* reset read/write statistics */
581 	priv->bytes_in = 0;
582 	priv->bytes_out = 0;
583 	priv->cmd_count = 0;
584 	priv->rx_flags = 0;
585 	spin_unlock_irqrestore(&priv->lock, flags);
586 
587 	/* Set termios */
588 	cypress_send(port);
589 
590 	if (tty)
591 		cypress_set_termios(tty, port, &priv->tmp_termios);
592 
593 	/* setup the port and start reading from the device */
594 	if (!port->interrupt_in_urb) {
595 		dev_err(&port->dev, "%s - interrupt_in_urb is empty!\n",
596 			__func__);
597 		return -1;
598 	}
599 
600 	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
601 		usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
602 		port->interrupt_in_urb->transfer_buffer,
603 		port->interrupt_in_urb->transfer_buffer_length,
604 		cypress_read_int_callback, port, priv->read_urb_interval);
605 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
606 
607 	if (result) {
608 		dev_err(&port->dev,
609 			"%s - failed submitting read urb, error %d\n",
610 							__func__, result);
611 		cypress_set_dead(port);
612 	}
613 	port->port.drain_delay = 256;
614 	return result;
615 } /* cypress_open */
616 
617 static void cypress_dtr_rts(struct usb_serial_port *port, int on)
618 {
619 	struct cypress_private *priv = usb_get_serial_port_data(port);
620 	/* drop dtr and rts */
621 	spin_lock_irq(&priv->lock);
622 	if (on == 0)
623 		priv->line_control = 0;
624 	else
625 		priv->line_control = CONTROL_DTR | CONTROL_RTS;
626 	priv->cmd_ctrl = 1;
627 	spin_unlock_irq(&priv->lock);
628 	cypress_write(NULL, port, NULL, 0);
629 }
630 
631 static void cypress_close(struct usb_serial_port *port)
632 {
633 	struct cypress_private *priv = usb_get_serial_port_data(port);
634 	unsigned long flags;
635 
636 	/* writing is potentially harmful, lock must be taken */
637 	mutex_lock(&port->serial->disc_mutex);
638 	if (port->serial->disconnected) {
639 		mutex_unlock(&port->serial->disc_mutex);
640 		return;
641 	}
642 	spin_lock_irqsave(&priv->lock, flags);
643 	kfifo_reset_out(&priv->write_fifo);
644 	spin_unlock_irqrestore(&priv->lock, flags);
645 
646 	dev_dbg(&port->dev, "%s - stopping urbs\n", __func__);
647 	usb_kill_urb(port->interrupt_in_urb);
648 	usb_kill_urb(port->interrupt_out_urb);
649 
650 	if (stats)
651 		dev_info(&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
652 			priv->bytes_in, priv->bytes_out, priv->cmd_count);
653 	mutex_unlock(&port->serial->disc_mutex);
654 } /* cypress_close */
655 
656 
657 static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
658 					const unsigned char *buf, int count)
659 {
660 	struct cypress_private *priv = usb_get_serial_port_data(port);
661 
662 	dev_dbg(&port->dev, "%s - port %d, %d bytes\n", __func__, port->number, count);
663 
664 	/* line control commands, which need to be executed immediately,
665 	   are not put into the buffer for obvious reasons.
666 	 */
667 	if (priv->cmd_ctrl) {
668 		count = 0;
669 		goto finish;
670 	}
671 
672 	if (!count)
673 		return count;
674 
675 	count = kfifo_in_locked(&priv->write_fifo, buf, count, &priv->lock);
676 
677 finish:
678 	cypress_send(port);
679 
680 	return count;
681 } /* cypress_write */
682 
683 
684 static void cypress_send(struct usb_serial_port *port)
685 {
686 	int count = 0, result, offset, actual_size;
687 	struct cypress_private *priv = usb_get_serial_port_data(port);
688 	struct device *dev = &port->dev;
689 	unsigned long flags;
690 
691 	if (!priv->comm_is_ok)
692 		return;
693 
694 	dev_dbg(dev, "%s - interrupt out size is %d\n", __func__,
695 		port->interrupt_out_size);
696 
697 	spin_lock_irqsave(&priv->lock, flags);
698 	if (priv->write_urb_in_use) {
699 		dev_dbg(dev, "%s - can't write, urb in use\n", __func__);
700 		spin_unlock_irqrestore(&priv->lock, flags);
701 		return;
702 	}
703 	spin_unlock_irqrestore(&priv->lock, flags);
704 
705 	/* clear buffer */
706 	memset(port->interrupt_out_urb->transfer_buffer, 0,
707 						port->interrupt_out_size);
708 
709 	spin_lock_irqsave(&priv->lock, flags);
710 	switch (priv->pkt_fmt) {
711 	default:
712 	case packet_format_1:
713 		/* this is for the CY7C64013... */
714 		offset = 2;
715 		port->interrupt_out_buffer[0] = priv->line_control;
716 		break;
717 	case packet_format_2:
718 		/* this is for the CY7C63743... */
719 		offset = 1;
720 		port->interrupt_out_buffer[0] = priv->line_control;
721 		break;
722 	}
723 
724 	if (priv->line_control & CONTROL_RESET)
725 		priv->line_control &= ~CONTROL_RESET;
726 
727 	if (priv->cmd_ctrl) {
728 		priv->cmd_count++;
729 		dev_dbg(dev, "%s - line control command being issued\n", __func__);
730 		spin_unlock_irqrestore(&priv->lock, flags);
731 		goto send;
732 	} else
733 		spin_unlock_irqrestore(&priv->lock, flags);
734 
735 	count = kfifo_out_locked(&priv->write_fifo,
736 					&port->interrupt_out_buffer[offset],
737 					port->interrupt_out_size - offset,
738 					&priv->lock);
739 	if (count == 0)
740 		return;
741 
742 	switch (priv->pkt_fmt) {
743 	default:
744 	case packet_format_1:
745 		port->interrupt_out_buffer[1] = count;
746 		break;
747 	case packet_format_2:
748 		port->interrupt_out_buffer[0] |= count;
749 	}
750 
751 	dev_dbg(dev, "%s - count is %d\n", __func__, count);
752 
753 send:
754 	spin_lock_irqsave(&priv->lock, flags);
755 	priv->write_urb_in_use = 1;
756 	spin_unlock_irqrestore(&priv->lock, flags);
757 
758 	if (priv->cmd_ctrl)
759 		actual_size = 1;
760 	else
761 		actual_size = count +
762 			      (priv->pkt_fmt == packet_format_1 ? 2 : 1);
763 
764 	usb_serial_debug_data(dev, __func__, port->interrupt_out_size,
765 			      port->interrupt_out_urb->transfer_buffer);
766 
767 	usb_fill_int_urb(port->interrupt_out_urb, port->serial->dev,
768 		usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
769 		port->interrupt_out_buffer, port->interrupt_out_size,
770 		cypress_write_int_callback, port, priv->write_urb_interval);
771 	result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
772 	if (result) {
773 		dev_err_console(port,
774 				"%s - failed submitting write urb, error %d\n",
775 							__func__, result);
776 		priv->write_urb_in_use = 0;
777 		cypress_set_dead(port);
778 	}
779 
780 	spin_lock_irqsave(&priv->lock, flags);
781 	if (priv->cmd_ctrl)
782 		priv->cmd_ctrl = 0;
783 
784 	/* do not count the line control and size bytes */
785 	priv->bytes_out += count;
786 	spin_unlock_irqrestore(&priv->lock, flags);
787 
788 	usb_serial_port_softint(port);
789 } /* cypress_send */
790 
791 
792 /* returns how much space is available in the soft buffer */
793 static int cypress_write_room(struct tty_struct *tty)
794 {
795 	struct usb_serial_port *port = tty->driver_data;
796 	struct cypress_private *priv = usb_get_serial_port_data(port);
797 	int room = 0;
798 	unsigned long flags;
799 
800 	spin_lock_irqsave(&priv->lock, flags);
801 	room = kfifo_avail(&priv->write_fifo);
802 	spin_unlock_irqrestore(&priv->lock, flags);
803 
804 	dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
805 	return room;
806 }
807 
808 
809 static int cypress_tiocmget(struct tty_struct *tty)
810 {
811 	struct usb_serial_port *port = tty->driver_data;
812 	struct cypress_private *priv = usb_get_serial_port_data(port);
813 	__u8 status, control;
814 	unsigned int result = 0;
815 	unsigned long flags;
816 
817 	spin_lock_irqsave(&priv->lock, flags);
818 	control = priv->line_control;
819 	status = priv->current_status;
820 	spin_unlock_irqrestore(&priv->lock, flags);
821 
822 	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
823 		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
824 		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
825 		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
826 		| ((status & UART_RI)         ? TIOCM_RI  : 0)
827 		| ((status & UART_CD)         ? TIOCM_CD  : 0);
828 
829 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
830 
831 	return result;
832 }
833 
834 
835 static int cypress_tiocmset(struct tty_struct *tty,
836 			       unsigned int set, unsigned int clear)
837 {
838 	struct usb_serial_port *port = tty->driver_data;
839 	struct cypress_private *priv = usb_get_serial_port_data(port);
840 	unsigned long flags;
841 
842 	spin_lock_irqsave(&priv->lock, flags);
843 	if (set & TIOCM_RTS)
844 		priv->line_control |= CONTROL_RTS;
845 	if (set & TIOCM_DTR)
846 		priv->line_control |= CONTROL_DTR;
847 	if (clear & TIOCM_RTS)
848 		priv->line_control &= ~CONTROL_RTS;
849 	if (clear & TIOCM_DTR)
850 		priv->line_control &= ~CONTROL_DTR;
851 	priv->cmd_ctrl = 1;
852 	spin_unlock_irqrestore(&priv->lock, flags);
853 
854 	return cypress_write(tty, port, NULL, 0);
855 }
856 
857 
858 static int cypress_ioctl(struct tty_struct *tty,
859 					unsigned int cmd, unsigned long arg)
860 {
861 	struct usb_serial_port *port = tty->driver_data;
862 	struct cypress_private *priv = usb_get_serial_port_data(port);
863 
864 	dev_dbg(&port->dev, "%s - port %d, cmd 0x%.4x\n", __func__, port->number, cmd);
865 
866 	switch (cmd) {
867 	/* This code comes from drivers/char/serial.c and ftdi_sio.c */
868 	case TIOCMIWAIT:
869 		for (;;) {
870 			interruptible_sleep_on(&port->delta_msr_wait);
871 			/* see if a signal did it */
872 			if (signal_pending(current))
873 				return -ERESTARTSYS;
874 
875 			if (port->serial->disconnected)
876 				return -EIO;
877 
878 			{
879 				char diff = priv->diff_status;
880 				if (diff == 0)
881 					return -EIO; /* no change => error */
882 
883 				/* consume all events */
884 				priv->diff_status = 0;
885 
886 				/* return 0 if caller wanted to know about
887 				   these bits */
888 				if (((arg & TIOCM_RNG) && (diff & UART_RI)) ||
889 				    ((arg & TIOCM_DSR) && (diff & UART_DSR)) ||
890 				    ((arg & TIOCM_CD) && (diff & UART_CD)) ||
891 				    ((arg & TIOCM_CTS) && (diff & UART_CTS)))
892 					return 0;
893 				/* otherwise caller can't care less about what
894 				 * happened, and so we continue to wait for
895 				 * more events.
896 				 */
897 			}
898 		}
899 		return 0;
900 	default:
901 		break;
902 	}
903 	dev_dbg(&port->dev, "%s - arg not supported - it was 0x%04x - check include/asm/ioctls.h\n", __func__, cmd);
904 	return -ENOIOCTLCMD;
905 } /* cypress_ioctl */
906 
907 
908 static void cypress_set_termios(struct tty_struct *tty,
909 	struct usb_serial_port *port, struct ktermios *old_termios)
910 {
911 	struct cypress_private *priv = usb_get_serial_port_data(port);
912 	struct device *dev = &port->dev;
913 	int data_bits, stop_bits, parity_type, parity_enable;
914 	unsigned cflag, iflag;
915 	unsigned long flags;
916 	__u8 oldlines;
917 	int linechange = 0;
918 
919 	spin_lock_irqsave(&priv->lock, flags);
920 	/* We can't clean this one up as we don't know the device type
921 	   early enough */
922 	if (!priv->termios_initialized) {
923 		if (priv->chiptype == CT_EARTHMATE) {
924 			tty->termios = tty_std_termios;
925 			tty->termios.c_cflag = B4800 | CS8 | CREAD | HUPCL |
926 				CLOCAL;
927 			tty->termios.c_ispeed = 4800;
928 			tty->termios.c_ospeed = 4800;
929 		} else if (priv->chiptype == CT_CYPHIDCOM) {
930 			tty->termios = tty_std_termios;
931 			tty->termios.c_cflag = B9600 | CS8 | CREAD | HUPCL |
932 				CLOCAL;
933 			tty->termios.c_ispeed = 9600;
934 			tty->termios.c_ospeed = 9600;
935 		} else if (priv->chiptype == CT_CA42V2) {
936 			tty->termios = tty_std_termios;
937 			tty->termios.c_cflag = B9600 | CS8 | CREAD | HUPCL |
938 				CLOCAL;
939 			tty->termios.c_ispeed = 9600;
940 			tty->termios.c_ospeed = 9600;
941 		}
942 		priv->termios_initialized = 1;
943 	}
944 	spin_unlock_irqrestore(&priv->lock, flags);
945 
946 	/* Unsupported features need clearing */
947 	tty->termios.c_cflag &= ~(CMSPAR|CRTSCTS);
948 
949 	cflag = tty->termios.c_cflag;
950 	iflag = tty->termios.c_iflag;
951 
952 	/* check if there are new settings */
953 	if (old_termios) {
954 		spin_lock_irqsave(&priv->lock, flags);
955 		priv->tmp_termios = tty->termios;
956 		spin_unlock_irqrestore(&priv->lock, flags);
957 	}
958 
959 	/* set number of data bits, parity, stop bits */
960 	/* when parity is disabled the parity type bit is ignored */
961 
962 	/* 1 means 2 stop bits, 0 means 1 stop bit */
963 	stop_bits = cflag & CSTOPB ? 1 : 0;
964 
965 	if (cflag & PARENB) {
966 		parity_enable = 1;
967 		/* 1 means odd parity, 0 means even parity */
968 		parity_type = cflag & PARODD ? 1 : 0;
969 	} else
970 		parity_enable = parity_type = 0;
971 
972 	switch (cflag & CSIZE) {
973 	case CS5:
974 		data_bits = 0;
975 		break;
976 	case CS6:
977 		data_bits = 1;
978 		break;
979 	case CS7:
980 		data_bits = 2;
981 		break;
982 	case CS8:
983 		data_bits = 3;
984 		break;
985 	default:
986 		dev_err(dev, "%s - CSIZE was set, but not CS5-CS8\n", __func__);
987 		data_bits = 3;
988 	}
989 	spin_lock_irqsave(&priv->lock, flags);
990 	oldlines = priv->line_control;
991 	if ((cflag & CBAUD) == B0) {
992 		/* drop dtr and rts */
993 		dev_dbg(dev, "%s - dropping the lines, baud rate 0bps\n", __func__);
994 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
995 	} else
996 		priv->line_control = (CONTROL_DTR | CONTROL_RTS);
997 	spin_unlock_irqrestore(&priv->lock, flags);
998 
999 	dev_dbg(dev, "%s - sending %d stop_bits, %d parity_enable, %d parity_type, %d data_bits (+5)\n",
1000 		__func__, stop_bits, parity_enable, parity_type, data_bits);
1001 
1002 	cypress_serial_control(tty, port, tty_get_baud_rate(tty),
1003 			data_bits, stop_bits,
1004 			parity_enable, parity_type,
1005 			0, CYPRESS_SET_CONFIG);
1006 
1007 	/* we perform a CYPRESS_GET_CONFIG so that the current settings are
1008 	 * filled into the private structure this should confirm that all is
1009 	 * working if it returns what we just set */
1010 	cypress_serial_control(tty, port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
1011 
1012 	/* Here we can define custom tty settings for devices; the main tty
1013 	 * termios flag base comes from empeg.c */
1014 
1015 	spin_lock_irqsave(&priv->lock, flags);
1016 	if (priv->chiptype == CT_EARTHMATE && priv->baud_rate == 4800) {
1017 		dev_dbg(dev, "Using custom termios settings for a baud rate of 4800bps.\n");
1018 		/* define custom termios settings for NMEA protocol */
1019 
1020 		tty->termios.c_iflag /* input modes - */
1021 			&= ~(IGNBRK  /* disable ignore break */
1022 			| BRKINT     /* disable break causes interrupt */
1023 			| PARMRK     /* disable mark parity errors */
1024 			| ISTRIP     /* disable clear high bit of input char */
1025 			| INLCR      /* disable translate NL to CR */
1026 			| IGNCR      /* disable ignore CR */
1027 			| ICRNL      /* disable translate CR to NL */
1028 			| IXON);     /* disable enable XON/XOFF flow control */
1029 
1030 		tty->termios.c_oflag /* output modes */
1031 			&= ~OPOST;    /* disable postprocess output char */
1032 
1033 		tty->termios.c_lflag /* line discipline modes */
1034 			&= ~(ECHO     /* disable echo input characters */
1035 			| ECHONL      /* disable echo new line */
1036 			| ICANON      /* disable erase, kill, werase, and rprnt
1037 					 special characters */
1038 			| ISIG        /* disable interrupt, quit, and suspend
1039 					 special characters */
1040 			| IEXTEN);    /* disable non-POSIX special characters */
1041 	} /* CT_CYPHIDCOM: Application should handle this for device */
1042 
1043 	linechange = (priv->line_control != oldlines);
1044 	spin_unlock_irqrestore(&priv->lock, flags);
1045 
1046 	/* if necessary, set lines */
1047 	if (linechange) {
1048 		priv->cmd_ctrl = 1;
1049 		cypress_write(tty, port, NULL, 0);
1050 	}
1051 } /* cypress_set_termios */
1052 
1053 
1054 /* returns amount of data still left in soft buffer */
1055 static int cypress_chars_in_buffer(struct tty_struct *tty)
1056 {
1057 	struct usb_serial_port *port = tty->driver_data;
1058 	struct cypress_private *priv = usb_get_serial_port_data(port);
1059 	int chars = 0;
1060 	unsigned long flags;
1061 
1062 	spin_lock_irqsave(&priv->lock, flags);
1063 	chars = kfifo_len(&priv->write_fifo);
1064 	spin_unlock_irqrestore(&priv->lock, flags);
1065 
1066 	dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars);
1067 	return chars;
1068 }
1069 
1070 
1071 static void cypress_throttle(struct tty_struct *tty)
1072 {
1073 	struct usb_serial_port *port = tty->driver_data;
1074 	struct cypress_private *priv = usb_get_serial_port_data(port);
1075 
1076 	spin_lock_irq(&priv->lock);
1077 	priv->rx_flags = THROTTLED;
1078 	spin_unlock_irq(&priv->lock);
1079 }
1080 
1081 
1082 static void cypress_unthrottle(struct tty_struct *tty)
1083 {
1084 	struct usb_serial_port *port = tty->driver_data;
1085 	struct cypress_private *priv = usb_get_serial_port_data(port);
1086 	int actually_throttled, result;
1087 
1088 	spin_lock_irq(&priv->lock);
1089 	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
1090 	priv->rx_flags = 0;
1091 	spin_unlock_irq(&priv->lock);
1092 
1093 	if (!priv->comm_is_ok)
1094 		return;
1095 
1096 	if (actually_throttled) {
1097 		result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
1098 		if (result) {
1099 			dev_err(&port->dev, "%s - failed submitting read urb, "
1100 					"error %d\n", __func__, result);
1101 			cypress_set_dead(port);
1102 		}
1103 	}
1104 }
1105 
1106 
1107 static void cypress_read_int_callback(struct urb *urb)
1108 {
1109 	struct usb_serial_port *port = urb->context;
1110 	struct cypress_private *priv = usb_get_serial_port_data(port);
1111 	struct device *dev = &urb->dev->dev;
1112 	struct tty_struct *tty;
1113 	unsigned char *data = urb->transfer_buffer;
1114 	unsigned long flags;
1115 	char tty_flag = TTY_NORMAL;
1116 	int havedata = 0;
1117 	int bytes = 0;
1118 	int result;
1119 	int i = 0;
1120 	int status = urb->status;
1121 
1122 	switch (status) {
1123 	case 0: /* success */
1124 		break;
1125 	case -ECONNRESET:
1126 	case -ENOENT:
1127 	case -ESHUTDOWN:
1128 		/* precursor to disconnect so just go away */
1129 		return;
1130 	case -EPIPE:
1131 		/* Can't call usb_clear_halt while in_interrupt */
1132 		/* FALLS THROUGH */
1133 	default:
1134 		/* something ugly is going on... */
1135 		dev_err(dev, "%s - unexpected nonzero read status received: %d\n",
1136 			__func__, status);
1137 		cypress_set_dead(port);
1138 		return;
1139 	}
1140 
1141 	spin_lock_irqsave(&priv->lock, flags);
1142 	if (priv->rx_flags & THROTTLED) {
1143 		dev_dbg(dev, "%s - now throttling\n", __func__);
1144 		priv->rx_flags |= ACTUALLY_THROTTLED;
1145 		spin_unlock_irqrestore(&priv->lock, flags);
1146 		return;
1147 	}
1148 	spin_unlock_irqrestore(&priv->lock, flags);
1149 
1150 	tty = tty_port_tty_get(&port->port);
1151 	if (!tty) {
1152 		dev_dbg(dev, "%s - bad tty pointer - exiting\n", __func__);
1153 		return;
1154 	}
1155 
1156 	spin_lock_irqsave(&priv->lock, flags);
1157 	result = urb->actual_length;
1158 	switch (priv->pkt_fmt) {
1159 	default:
1160 	case packet_format_1:
1161 		/* This is for the CY7C64013... */
1162 		priv->current_status = data[0] & 0xF8;
1163 		bytes = data[1] + 2;
1164 		i = 2;
1165 		if (bytes > 2)
1166 			havedata = 1;
1167 		break;
1168 	case packet_format_2:
1169 		/* This is for the CY7C63743... */
1170 		priv->current_status = data[0] & 0xF8;
1171 		bytes = (data[0] & 0x07) + 1;
1172 		i = 1;
1173 		if (bytes > 1)
1174 			havedata = 1;
1175 		break;
1176 	}
1177 	spin_unlock_irqrestore(&priv->lock, flags);
1178 	if (result < bytes) {
1179 		dev_dbg(dev,
1180 			"%s - wrong packet size - received %d bytes but packet said %d bytes\n",
1181 			__func__, result, bytes);
1182 		goto continue_read;
1183 	}
1184 
1185 	usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
1186 
1187 	spin_lock_irqsave(&priv->lock, flags);
1188 	/* check to see if status has changed */
1189 	if (priv->current_status != priv->prev_status) {
1190 		priv->diff_status |= priv->current_status ^
1191 			priv->prev_status;
1192 		wake_up_interruptible(&port->delta_msr_wait);
1193 		priv->prev_status = priv->current_status;
1194 	}
1195 	spin_unlock_irqrestore(&priv->lock, flags);
1196 
1197 	/* hangup, as defined in acm.c... this might be a bad place for it
1198 	 * though */
1199 	if (tty && !(tty->termios.c_cflag & CLOCAL) &&
1200 			!(priv->current_status & UART_CD)) {
1201 		dev_dbg(dev, "%s - calling hangup\n", __func__);
1202 		tty_hangup(tty);
1203 		goto continue_read;
1204 	}
1205 
1206 	/* There is one error bit... I'm assuming it is a parity error
1207 	 * indicator as the generic firmware will set this bit to 1 if a
1208 	 * parity error occurs.
1209 	 * I can not find reference to any other error events. */
1210 	spin_lock_irqsave(&priv->lock, flags);
1211 	if (priv->current_status & CYP_ERROR) {
1212 		spin_unlock_irqrestore(&priv->lock, flags);
1213 		tty_flag = TTY_PARITY;
1214 		dev_dbg(dev, "%s - Parity Error detected\n", __func__);
1215 	} else
1216 		spin_unlock_irqrestore(&priv->lock, flags);
1217 
1218 	/* process read if there is data other than line status */
1219 	if (bytes > i) {
1220 		tty_insert_flip_string_fixed_flag(&port->port, data + i,
1221 				tty_flag, bytes - i);
1222 		tty_flip_buffer_push(&port->port);
1223 	}
1224 
1225 	spin_lock_irqsave(&priv->lock, flags);
1226 	/* control and status byte(s) are also counted */
1227 	priv->bytes_in += bytes;
1228 	spin_unlock_irqrestore(&priv->lock, flags);
1229 
1230 continue_read:
1231 	tty_kref_put(tty);
1232 
1233 	/* Continue trying to always read */
1234 
1235 	if (priv->comm_is_ok) {
1236 		usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1237 				usb_rcvintpipe(port->serial->dev,
1238 					port->interrupt_in_endpointAddress),
1239 				port->interrupt_in_urb->transfer_buffer,
1240 				port->interrupt_in_urb->transfer_buffer_length,
1241 				cypress_read_int_callback, port,
1242 				priv->read_urb_interval);
1243 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1244 		if (result && result != -EPERM) {
1245 			dev_err(dev, "%s - failed resubmitting read urb, error %d\n",
1246 				__func__, result);
1247 			cypress_set_dead(port);
1248 		}
1249 	}
1250 } /* cypress_read_int_callback */
1251 
1252 
1253 static void cypress_write_int_callback(struct urb *urb)
1254 {
1255 	struct usb_serial_port *port = urb->context;
1256 	struct cypress_private *priv = usb_get_serial_port_data(port);
1257 	struct device *dev = &urb->dev->dev;
1258 	int result;
1259 	int status = urb->status;
1260 
1261 	switch (status) {
1262 	case 0:
1263 		/* success */
1264 		break;
1265 	case -ECONNRESET:
1266 	case -ENOENT:
1267 	case -ESHUTDOWN:
1268 		/* this urb is terminated, clean up */
1269 		dev_dbg(dev, "%s - urb shutting down with status: %d\n",
1270 			__func__, status);
1271 		priv->write_urb_in_use = 0;
1272 		return;
1273 	case -EPIPE: /* no break needed; clear halt and resubmit */
1274 		if (!priv->comm_is_ok)
1275 			break;
1276 		usb_clear_halt(port->serial->dev, 0x02);
1277 		/* error in the urb, so we have to resubmit it */
1278 		dev_dbg(dev, "%s - nonzero write bulk status received: %d\n",
1279 			__func__, status);
1280 		port->interrupt_out_urb->transfer_buffer_length = 1;
1281 		result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
1282 		if (!result)
1283 			return;
1284 		dev_err(dev, "%s - failed resubmitting write urb, error %d\n",
1285 			__func__, result);
1286 		cypress_set_dead(port);
1287 		break;
1288 	default:
1289 		dev_err(dev, "%s - unexpected nonzero write status received: %d\n",
1290 			__func__, status);
1291 		cypress_set_dead(port);
1292 		break;
1293 	}
1294 	priv->write_urb_in_use = 0;
1295 
1296 	/* send any buffered data */
1297 	cypress_send(port);
1298 }
1299 
1300 module_usb_serial_driver(serial_drivers, id_table_combined);
1301 
1302 MODULE_AUTHOR(DRIVER_AUTHOR);
1303 MODULE_DESCRIPTION(DRIVER_DESC);
1304 MODULE_LICENSE("GPL");
1305 
1306 module_param(stats, bool, S_IRUGO | S_IWUSR);
1307 MODULE_PARM_DESC(stats, "Enable statistics or not");
1308 module_param(interval, int, S_IRUGO | S_IWUSR);
1309 MODULE_PARM_DESC(interval, "Overrides interrupt interval");
1310 module_param(unstable_bauds, bool, S_IRUGO | S_IWUSR);
1311 MODULE_PARM_DESC(unstable_bauds, "Allow unstable baud rates");
1312