xref: /openbmc/linux/drivers/usb/serial/cypress_m8.c (revision 5bd8e16d)
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 	{ USB_DEVICE(VENDOR_ID_FRWD, PRODUCT_ID_CYPHIDCOM_FRWD) },
69 	{ }						/* Terminating entry */
70 };
71 
72 static const struct usb_device_id id_table_nokiaca42v2[] = {
73 	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
74 	{ }						/* Terminating entry */
75 };
76 
77 static const struct usb_device_id id_table_combined[] = {
78 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
79 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
80 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
81 	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
82 	{ USB_DEVICE(VENDOR_ID_FRWD, PRODUCT_ID_CYPHIDCOM_FRWD) },
83 	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
84 	{ }						/* Terminating entry */
85 };
86 
87 MODULE_DEVICE_TABLE(usb, id_table_combined);
88 
89 enum packet_format {
90 	packet_format_1,  /* b0:status, b1:payload count */
91 	packet_format_2   /* b0[7:3]:status, b0[2:0]:payload count */
92 };
93 
94 struct cypress_private {
95 	spinlock_t lock;		   /* private lock */
96 	int chiptype;			   /* identifier of device, for quirks/etc */
97 	int bytes_in;			   /* used for statistics */
98 	int bytes_out;			   /* used for statistics */
99 	int cmd_count;			   /* used for statistics */
100 	int cmd_ctrl;			   /* always set this to 1 before issuing a command */
101 	struct kfifo write_fifo;	   /* write fifo */
102 	int write_urb_in_use;		   /* write urb in use indicator */
103 	int write_urb_interval;            /* interval to use for write urb */
104 	int read_urb_interval;             /* interval to use for read urb */
105 	int comm_is_ok;                    /* true if communication is (still) ok */
106 	int termios_initialized;
107 	__u8 line_control;	   	   /* holds dtr / rts value */
108 	__u8 current_status;	   	   /* received from last read - info on dsr,cts,cd,ri,etc */
109 	__u8 current_config;	   	   /* stores the current configuration byte */
110 	__u8 rx_flags;			   /* throttling - used from whiteheat/ftdi_sio */
111 	enum packet_format pkt_fmt;	   /* format to use for packet send / receive */
112 	int get_cfg_unsafe;		   /* If true, the CYPRESS_GET_CONFIG is unsafe */
113 	int baud_rate;			   /* stores current baud rate in
114 					      integer form */
115 	int isthrottled;		   /* if throttled, discard reads */
116 	char prev_status, diff_status;	   /* used for TIOCMIWAIT */
117 	/* we pass a pointer to this as the argument sent to
118 	   cypress_set_termios old_termios */
119 	struct ktermios tmp_termios; 	   /* stores the old termios settings */
120 };
121 
122 /* function prototypes for the Cypress USB to serial device */
123 static int  cypress_earthmate_port_probe(struct usb_serial_port *port);
124 static int  cypress_hidcom_port_probe(struct usb_serial_port *port);
125 static int  cypress_ca42v2_port_probe(struct usb_serial_port *port);
126 static int  cypress_port_remove(struct usb_serial_port *port);
127 static int  cypress_open(struct tty_struct *tty, struct usb_serial_port *port);
128 static void cypress_close(struct usb_serial_port *port);
129 static void cypress_dtr_rts(struct usb_serial_port *port, int on);
130 static int  cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
131 			const unsigned char *buf, int count);
132 static void cypress_send(struct usb_serial_port *port);
133 static int  cypress_write_room(struct tty_struct *tty);
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_tiocmiwait(struct tty_struct *tty, unsigned long arg);
140 static int  cypress_chars_in_buffer(struct tty_struct *tty);
141 static void cypress_throttle(struct tty_struct *tty);
142 static void cypress_unthrottle(struct tty_struct *tty);
143 static void cypress_set_dead(struct usb_serial_port *port);
144 static void cypress_read_int_callback(struct urb *urb);
145 static void cypress_write_int_callback(struct urb *urb);
146 
147 static struct usb_serial_driver cypress_earthmate_device = {
148 	.driver = {
149 		.owner =		THIS_MODULE,
150 		.name =			"earthmate",
151 	},
152 	.description =			"DeLorme Earthmate USB",
153 	.id_table =			id_table_earthmate,
154 	.num_ports =			1,
155 	.port_probe =			cypress_earthmate_port_probe,
156 	.port_remove =			cypress_port_remove,
157 	.open =				cypress_open,
158 	.close =			cypress_close,
159 	.dtr_rts =			cypress_dtr_rts,
160 	.write =			cypress_write,
161 	.write_room =			cypress_write_room,
162 	.set_termios =			cypress_set_termios,
163 	.tiocmget =			cypress_tiocmget,
164 	.tiocmset =			cypress_tiocmset,
165 	.tiocmiwait =			cypress_tiocmiwait,
166 	.chars_in_buffer =		cypress_chars_in_buffer,
167 	.throttle =		 	cypress_throttle,
168 	.unthrottle =			cypress_unthrottle,
169 	.read_int_callback =		cypress_read_int_callback,
170 	.write_int_callback =		cypress_write_int_callback,
171 };
172 
173 static struct usb_serial_driver cypress_hidcom_device = {
174 	.driver = {
175 		.owner =		THIS_MODULE,
176 		.name =			"cyphidcom",
177 	},
178 	.description =			"HID->COM RS232 Adapter",
179 	.id_table =			id_table_cyphidcomrs232,
180 	.num_ports =			1,
181 	.port_probe =			cypress_hidcom_port_probe,
182 	.port_remove =			cypress_port_remove,
183 	.open =				cypress_open,
184 	.close =			cypress_close,
185 	.dtr_rts =			cypress_dtr_rts,
186 	.write =			cypress_write,
187 	.write_room =			cypress_write_room,
188 	.set_termios =			cypress_set_termios,
189 	.tiocmget =			cypress_tiocmget,
190 	.tiocmset =			cypress_tiocmset,
191 	.tiocmiwait =			cypress_tiocmiwait,
192 	.chars_in_buffer =		cypress_chars_in_buffer,
193 	.throttle =			cypress_throttle,
194 	.unthrottle =			cypress_unthrottle,
195 	.read_int_callback =		cypress_read_int_callback,
196 	.write_int_callback =		cypress_write_int_callback,
197 };
198 
199 static struct usb_serial_driver cypress_ca42v2_device = {
200 	.driver = {
201 		.owner =		THIS_MODULE,
202 		.name =			"nokiaca42v2",
203 	},
204 	.description =			"Nokia CA-42 V2 Adapter",
205 	.id_table =			id_table_nokiaca42v2,
206 	.num_ports =			1,
207 	.port_probe =			cypress_ca42v2_port_probe,
208 	.port_remove =			cypress_port_remove,
209 	.open =				cypress_open,
210 	.close =			cypress_close,
211 	.dtr_rts =			cypress_dtr_rts,
212 	.write =			cypress_write,
213 	.write_room =			cypress_write_room,
214 	.set_termios =			cypress_set_termios,
215 	.tiocmget =			cypress_tiocmget,
216 	.tiocmset =			cypress_tiocmset,
217 	.tiocmiwait =			cypress_tiocmiwait,
218 	.chars_in_buffer =		cypress_chars_in_buffer,
219 	.throttle =			cypress_throttle,
220 	.unthrottle =			cypress_unthrottle,
221 	.read_int_callback =		cypress_read_int_callback,
222 	.write_int_callback =		cypress_write_int_callback,
223 };
224 
225 static struct usb_serial_driver * const serial_drivers[] = {
226 	&cypress_earthmate_device, &cypress_hidcom_device,
227 	&cypress_ca42v2_device, NULL
228 };
229 
230 /*****************************************************************************
231  * Cypress serial helper functions
232  *****************************************************************************/
233 
234 /* FRWD Dongle hidcom needs to skip reset and speed checks */
235 static inline bool is_frwd(struct usb_device *dev)
236 {
237 	return ((le16_to_cpu(dev->descriptor.idVendor) == VENDOR_ID_FRWD) &&
238 		(le16_to_cpu(dev->descriptor.idProduct) == PRODUCT_ID_CYPHIDCOM_FRWD));
239 }
240 
241 static int analyze_baud_rate(struct usb_serial_port *port, speed_t new_rate)
242 {
243 	struct cypress_private *priv;
244 	priv = usb_get_serial_port_data(port);
245 
246 	if (unstable_bauds)
247 		return new_rate;
248 
249 	/* FRWD Dongle uses 115200 bps */
250 	if (is_frwd(port->serial->dev))
251 		return new_rate;
252 
253 	/*
254 	 * The general purpose firmware for the Cypress M8 allows for
255 	 * a maximum speed of 57600bps (I have no idea whether DeLorme
256 	 * chose to use the general purpose firmware or not), if you
257 	 * need to modify this speed setting for your own project
258 	 * please add your own chiptype and modify the code likewise.
259 	 * The Cypress HID->COM device will work successfully up to
260 	 * 115200bps (but the actual throughput is around 3kBps).
261 	 */
262 	if (port->serial->dev->speed == USB_SPEED_LOW) {
263 		/*
264 		 * Mike Isely <isely@pobox.com> 2-Feb-2008: The
265 		 * Cypress app note that describes this mechanism
266 		 * states the the low-speed part can't handle more
267 		 * than 800 bytes/sec, in which case 4800 baud is the
268 		 * safest speed for a part like that.
269 		 */
270 		if (new_rate > 4800) {
271 			dev_dbg(&port->dev,
272 				"%s - failed setting baud rate, device incapable speed %d\n",
273 				__func__, new_rate);
274 			return -1;
275 		}
276 	}
277 	switch (priv->chiptype) {
278 	case CT_EARTHMATE:
279 		if (new_rate <= 600) {
280 			/* 300 and 600 baud rates are supported under
281 			 * the generic firmware, but are not used with
282 			 * NMEA and SiRF protocols */
283 			dev_dbg(&port->dev,
284 				"%s - failed setting baud rate, unsupported speed of %d on Earthmate GPS",
285 				__func__, new_rate);
286 			return -1;
287 		}
288 		break;
289 	default:
290 		break;
291 	}
292 	return new_rate;
293 }
294 
295 
296 /* This function can either set or retrieve the current serial line settings */
297 static int cypress_serial_control(struct tty_struct *tty,
298 	struct usb_serial_port *port, speed_t baud_rate, int data_bits,
299 	int stop_bits, int parity_enable, int parity_type, int reset,
300 	int cypress_request_type)
301 {
302 	int new_baudrate = 0, retval = 0, tries = 0;
303 	struct cypress_private *priv;
304 	struct device *dev = &port->dev;
305 	u8 *feature_buffer;
306 	const unsigned int feature_len = 5;
307 	unsigned long flags;
308 
309 	priv = usb_get_serial_port_data(port);
310 
311 	if (!priv->comm_is_ok)
312 		return -ENODEV;
313 
314 	feature_buffer = kcalloc(feature_len, sizeof(u8), GFP_KERNEL);
315 	if (!feature_buffer)
316 		return -ENOMEM;
317 
318 	switch (cypress_request_type) {
319 	case CYPRESS_SET_CONFIG:
320 		/* 0 means 'Hang up' so doesn't change the true bit rate */
321 		new_baudrate = priv->baud_rate;
322 		if (baud_rate && baud_rate != priv->baud_rate) {
323 			dev_dbg(dev, "%s - baud rate is changing\n", __func__);
324 			retval = analyze_baud_rate(port, baud_rate);
325 			if (retval >= 0) {
326 				new_baudrate = retval;
327 				dev_dbg(dev, "%s - New baud rate set to %d\n",
328 					__func__, new_baudrate);
329 			}
330 		}
331 		dev_dbg(dev, "%s - baud rate is being sent as %d\n", __func__,
332 			new_baudrate);
333 
334 		/* fill the feature_buffer with new configuration */
335 		put_unaligned_le32(new_baudrate, feature_buffer);
336 		feature_buffer[4] |= data_bits;   /* assign data bits in 2 bit space ( max 3 ) */
337 		/* 1 bit gap */
338 		feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
339 		feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
340 		feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
341 		/* 1 bit gap */
342 		feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
343 
344 		dev_dbg(dev, "%s - device is being sent this feature report:\n", __func__);
345 		dev_dbg(dev, "%s - %02X - %02X - %02X - %02X - %02X\n", __func__,
346 			feature_buffer[0], feature_buffer[1],
347 			feature_buffer[2], feature_buffer[3],
348 			feature_buffer[4]);
349 
350 		do {
351 			retval = usb_control_msg(port->serial->dev,
352 					usb_sndctrlpipe(port->serial->dev, 0),
353 					HID_REQ_SET_REPORT,
354 					USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
355 					0x0300, 0, feature_buffer,
356 					feature_len, 500);
357 
358 			if (tries++ >= 3)
359 				break;
360 
361 		} while (retval != feature_len &&
362 			 retval != -ENODEV);
363 
364 		if (retval != feature_len) {
365 			dev_err(dev, "%s - failed sending serial line settings - %d\n",
366 				__func__, retval);
367 			cypress_set_dead(port);
368 		} else {
369 			spin_lock_irqsave(&priv->lock, flags);
370 			priv->baud_rate = new_baudrate;
371 			priv->current_config = feature_buffer[4];
372 			spin_unlock_irqrestore(&priv->lock, flags);
373 			/* If we asked for a speed change encode it */
374 			if (baud_rate)
375 				tty_encode_baud_rate(tty,
376 					new_baudrate, new_baudrate);
377 		}
378 	break;
379 	case CYPRESS_GET_CONFIG:
380 		if (priv->get_cfg_unsafe) {
381 			/* Not implemented for this device,
382 			   and if we try to do it we're likely
383 			   to crash the hardware. */
384 			retval = -ENOTTY;
385 			goto out;
386 		}
387 		dev_dbg(dev, "%s - retreiving serial line settings\n", __func__);
388 		do {
389 			retval = usb_control_msg(port->serial->dev,
390 					usb_rcvctrlpipe(port->serial->dev, 0),
391 					HID_REQ_GET_REPORT,
392 					USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
393 					0x0300, 0, feature_buffer,
394 					feature_len, 500);
395 
396 			if (tries++ >= 3)
397 				break;
398 		} while (retval != feature_len
399 						&& retval != -ENODEV);
400 
401 		if (retval != feature_len) {
402 			dev_err(dev, "%s - failed to retrieve serial line settings - %d\n",
403 				__func__, retval);
404 			cypress_set_dead(port);
405 			goto out;
406 		} else {
407 			spin_lock_irqsave(&priv->lock, flags);
408 			/* store the config in one byte, and later
409 			   use bit masks to check values */
410 			priv->current_config = feature_buffer[4];
411 			priv->baud_rate = get_unaligned_le32(feature_buffer);
412 			spin_unlock_irqrestore(&priv->lock, flags);
413 		}
414 	}
415 	spin_lock_irqsave(&priv->lock, flags);
416 	++priv->cmd_count;
417 	spin_unlock_irqrestore(&priv->lock, flags);
418 out:
419 	kfree(feature_buffer);
420 	return retval;
421 } /* cypress_serial_control */
422 
423 
424 static void cypress_set_dead(struct usb_serial_port *port)
425 {
426 	struct cypress_private *priv = usb_get_serial_port_data(port);
427 	unsigned long flags;
428 
429 	spin_lock_irqsave(&priv->lock, flags);
430 	if (!priv->comm_is_ok) {
431 		spin_unlock_irqrestore(&priv->lock, flags);
432 		return;
433 	}
434 	priv->comm_is_ok = 0;
435 	spin_unlock_irqrestore(&priv->lock, flags);
436 
437 	dev_err(&port->dev, "cypress_m8 suspending failing port %d - "
438 		"interval might be too short\n", port->port_number);
439 }
440 
441 
442 /*****************************************************************************
443  * Cypress serial driver functions
444  *****************************************************************************/
445 
446 
447 static int cypress_generic_port_probe(struct usb_serial_port *port)
448 {
449 	struct usb_serial *serial = port->serial;
450 	struct cypress_private *priv;
451 
452 	priv = kzalloc(sizeof(struct cypress_private), GFP_KERNEL);
453 	if (!priv)
454 		return -ENOMEM;
455 
456 	priv->comm_is_ok = !0;
457 	spin_lock_init(&priv->lock);
458 	if (kfifo_alloc(&priv->write_fifo, CYPRESS_BUF_SIZE, GFP_KERNEL)) {
459 		kfree(priv);
460 		return -ENOMEM;
461 	}
462 
463 	/* Skip reset for FRWD device. It is a workaound:
464 	   device hangs if it receives SET_CONFIGURE in Configured
465 	   state. */
466 	if (!is_frwd(serial->dev))
467 		usb_reset_configuration(serial->dev);
468 
469 	priv->cmd_ctrl = 0;
470 	priv->line_control = 0;
471 	priv->termios_initialized = 0;
472 	priv->rx_flags = 0;
473 	/* Default packet format setting is determined by packet size.
474 	   Anything with a size larger then 9 must have a separate
475 	   count field since the 3 bit count field is otherwise too
476 	   small.  Otherwise we can use the slightly more compact
477 	   format.  This is in accordance with the cypress_m8 serial
478 	   converter app note. */
479 	if (port->interrupt_out_size > 9)
480 		priv->pkt_fmt = packet_format_1;
481 	else
482 		priv->pkt_fmt = packet_format_2;
483 
484 	if (interval > 0) {
485 		priv->write_urb_interval = interval;
486 		priv->read_urb_interval = interval;
487 		dev_dbg(&port->dev, "%s - read & write intervals forced to %d\n",
488 			__func__, interval);
489 	} else {
490 		priv->write_urb_interval = port->interrupt_out_urb->interval;
491 		priv->read_urb_interval = port->interrupt_in_urb->interval;
492 		dev_dbg(&port->dev, "%s - intervals: read=%d write=%d\n",
493 			__func__, priv->read_urb_interval,
494 			priv->write_urb_interval);
495 	}
496 	usb_set_serial_port_data(port, priv);
497 
498 	port->port.drain_delay = 256;
499 
500 	return 0;
501 }
502 
503 
504 static int cypress_earthmate_port_probe(struct usb_serial_port *port)
505 {
506 	struct usb_serial *serial = port->serial;
507 	struct cypress_private *priv;
508 	int ret;
509 
510 	ret = cypress_generic_port_probe(port);
511 	if (ret) {
512 		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
513 		return ret;
514 	}
515 
516 	priv = usb_get_serial_port_data(port);
517 	priv->chiptype = CT_EARTHMATE;
518 	/* All Earthmate devices use the separated-count packet
519 	   format!  Idiotic. */
520 	priv->pkt_fmt = packet_format_1;
521 	if (serial->dev->descriptor.idProduct !=
522 				cpu_to_le16(PRODUCT_ID_EARTHMATEUSB)) {
523 		/* The old original USB Earthmate seemed able to
524 		   handle GET_CONFIG requests; everything they've
525 		   produced since that time crashes if this command is
526 		   attempted :-( */
527 		dev_dbg(&port->dev,
528 			"%s - Marking this device as unsafe for GET_CONFIG commands\n",
529 			__func__);
530 		priv->get_cfg_unsafe = !0;
531 	}
532 
533 	return 0;
534 }
535 
536 static int cypress_hidcom_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_CYPHIDCOM;
549 
550 	return 0;
551 }
552 
553 static int cypress_ca42v2_port_probe(struct usb_serial_port *port)
554 {
555 	struct cypress_private *priv;
556 	int ret;
557 
558 	ret = cypress_generic_port_probe(port);
559 	if (ret) {
560 		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
561 		return ret;
562 	}
563 
564 	priv = usb_get_serial_port_data(port);
565 	priv->chiptype = CT_CA42V2;
566 
567 	return 0;
568 }
569 
570 static int cypress_port_remove(struct usb_serial_port *port)
571 {
572 	struct cypress_private *priv;
573 
574 	priv = usb_get_serial_port_data(port);
575 
576 	kfifo_free(&priv->write_fifo);
577 	kfree(priv);
578 
579 	return 0;
580 }
581 
582 static int cypress_open(struct tty_struct *tty, struct usb_serial_port *port)
583 {
584 	struct cypress_private *priv = usb_get_serial_port_data(port);
585 	struct usb_serial *serial = port->serial;
586 	unsigned long flags;
587 	int result = 0;
588 
589 	if (!priv->comm_is_ok)
590 		return -EIO;
591 
592 	/* clear halts before open */
593 	usb_clear_halt(serial->dev, 0x81);
594 	usb_clear_halt(serial->dev, 0x02);
595 
596 	spin_lock_irqsave(&priv->lock, flags);
597 	/* reset read/write statistics */
598 	priv->bytes_in = 0;
599 	priv->bytes_out = 0;
600 	priv->cmd_count = 0;
601 	priv->rx_flags = 0;
602 	spin_unlock_irqrestore(&priv->lock, flags);
603 
604 	/* Set termios */
605 	cypress_send(port);
606 
607 	if (tty)
608 		cypress_set_termios(tty, port, &priv->tmp_termios);
609 
610 	/* setup the port and start reading from the device */
611 	if (!port->interrupt_in_urb) {
612 		dev_err(&port->dev, "%s - interrupt_in_urb is empty!\n",
613 			__func__);
614 		return -1;
615 	}
616 
617 	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
618 		usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
619 		port->interrupt_in_urb->transfer_buffer,
620 		port->interrupt_in_urb->transfer_buffer_length,
621 		cypress_read_int_callback, port, priv->read_urb_interval);
622 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
623 
624 	if (result) {
625 		dev_err(&port->dev,
626 			"%s - failed submitting read urb, error %d\n",
627 							__func__, result);
628 		cypress_set_dead(port);
629 	}
630 
631 	return result;
632 } /* cypress_open */
633 
634 static void cypress_dtr_rts(struct usb_serial_port *port, int on)
635 {
636 	struct cypress_private *priv = usb_get_serial_port_data(port);
637 	/* drop dtr and rts */
638 	spin_lock_irq(&priv->lock);
639 	if (on == 0)
640 		priv->line_control = 0;
641 	else
642 		priv->line_control = CONTROL_DTR | CONTROL_RTS;
643 	priv->cmd_ctrl = 1;
644 	spin_unlock_irq(&priv->lock);
645 	cypress_write(NULL, port, NULL, 0);
646 }
647 
648 static void cypress_close(struct usb_serial_port *port)
649 {
650 	struct cypress_private *priv = usb_get_serial_port_data(port);
651 	unsigned long flags;
652 
653 	spin_lock_irqsave(&priv->lock, flags);
654 	kfifo_reset_out(&priv->write_fifo);
655 	spin_unlock_irqrestore(&priv->lock, flags);
656 
657 	dev_dbg(&port->dev, "%s - stopping urbs\n", __func__);
658 	usb_kill_urb(port->interrupt_in_urb);
659 	usb_kill_urb(port->interrupt_out_urb);
660 
661 	if (stats)
662 		dev_info(&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
663 			priv->bytes_in, priv->bytes_out, priv->cmd_count);
664 } /* cypress_close */
665 
666 
667 static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
668 					const unsigned char *buf, int count)
669 {
670 	struct cypress_private *priv = usb_get_serial_port_data(port);
671 
672 	dev_dbg(&port->dev, "%s - %d bytes\n", __func__, count);
673 
674 	/* line control commands, which need to be executed immediately,
675 	   are not put into the buffer for obvious reasons.
676 	 */
677 	if (priv->cmd_ctrl) {
678 		count = 0;
679 		goto finish;
680 	}
681 
682 	if (!count)
683 		return count;
684 
685 	count = kfifo_in_locked(&priv->write_fifo, buf, count, &priv->lock);
686 
687 finish:
688 	cypress_send(port);
689 
690 	return count;
691 } /* cypress_write */
692 
693 
694 static void cypress_send(struct usb_serial_port *port)
695 {
696 	int count = 0, result, offset, actual_size;
697 	struct cypress_private *priv = usb_get_serial_port_data(port);
698 	struct device *dev = &port->dev;
699 	unsigned long flags;
700 
701 	if (!priv->comm_is_ok)
702 		return;
703 
704 	dev_dbg(dev, "%s - interrupt out size is %d\n", __func__,
705 		port->interrupt_out_size);
706 
707 	spin_lock_irqsave(&priv->lock, flags);
708 	if (priv->write_urb_in_use) {
709 		dev_dbg(dev, "%s - can't write, urb in use\n", __func__);
710 		spin_unlock_irqrestore(&priv->lock, flags);
711 		return;
712 	}
713 	spin_unlock_irqrestore(&priv->lock, flags);
714 
715 	/* clear buffer */
716 	memset(port->interrupt_out_urb->transfer_buffer, 0,
717 						port->interrupt_out_size);
718 
719 	spin_lock_irqsave(&priv->lock, flags);
720 	switch (priv->pkt_fmt) {
721 	default:
722 	case packet_format_1:
723 		/* this is for the CY7C64013... */
724 		offset = 2;
725 		port->interrupt_out_buffer[0] = priv->line_control;
726 		break;
727 	case packet_format_2:
728 		/* this is for the CY7C63743... */
729 		offset = 1;
730 		port->interrupt_out_buffer[0] = priv->line_control;
731 		break;
732 	}
733 
734 	if (priv->line_control & CONTROL_RESET)
735 		priv->line_control &= ~CONTROL_RESET;
736 
737 	if (priv->cmd_ctrl) {
738 		priv->cmd_count++;
739 		dev_dbg(dev, "%s - line control command being issued\n", __func__);
740 		spin_unlock_irqrestore(&priv->lock, flags);
741 		goto send;
742 	} else
743 		spin_unlock_irqrestore(&priv->lock, flags);
744 
745 	count = kfifo_out_locked(&priv->write_fifo,
746 					&port->interrupt_out_buffer[offset],
747 					port->interrupt_out_size - offset,
748 					&priv->lock);
749 	if (count == 0)
750 		return;
751 
752 	switch (priv->pkt_fmt) {
753 	default:
754 	case packet_format_1:
755 		port->interrupt_out_buffer[1] = count;
756 		break;
757 	case packet_format_2:
758 		port->interrupt_out_buffer[0] |= count;
759 	}
760 
761 	dev_dbg(dev, "%s - count is %d\n", __func__, count);
762 
763 send:
764 	spin_lock_irqsave(&priv->lock, flags);
765 	priv->write_urb_in_use = 1;
766 	spin_unlock_irqrestore(&priv->lock, flags);
767 
768 	if (priv->cmd_ctrl)
769 		actual_size = 1;
770 	else
771 		actual_size = count +
772 			      (priv->pkt_fmt == packet_format_1 ? 2 : 1);
773 
774 	usb_serial_debug_data(dev, __func__, port->interrupt_out_size,
775 			      port->interrupt_out_urb->transfer_buffer);
776 
777 	usb_fill_int_urb(port->interrupt_out_urb, port->serial->dev,
778 		usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
779 		port->interrupt_out_buffer, port->interrupt_out_size,
780 		cypress_write_int_callback, port, priv->write_urb_interval);
781 	result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
782 	if (result) {
783 		dev_err_console(port,
784 				"%s - failed submitting write urb, error %d\n",
785 							__func__, result);
786 		priv->write_urb_in_use = 0;
787 		cypress_set_dead(port);
788 	}
789 
790 	spin_lock_irqsave(&priv->lock, flags);
791 	if (priv->cmd_ctrl)
792 		priv->cmd_ctrl = 0;
793 
794 	/* do not count the line control and size bytes */
795 	priv->bytes_out += count;
796 	spin_unlock_irqrestore(&priv->lock, flags);
797 
798 	usb_serial_port_softint(port);
799 } /* cypress_send */
800 
801 
802 /* returns how much space is available in the soft buffer */
803 static int cypress_write_room(struct tty_struct *tty)
804 {
805 	struct usb_serial_port *port = tty->driver_data;
806 	struct cypress_private *priv = usb_get_serial_port_data(port);
807 	int room = 0;
808 	unsigned long flags;
809 
810 	spin_lock_irqsave(&priv->lock, flags);
811 	room = kfifo_avail(&priv->write_fifo);
812 	spin_unlock_irqrestore(&priv->lock, flags);
813 
814 	dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
815 	return room;
816 }
817 
818 
819 static int cypress_tiocmget(struct tty_struct *tty)
820 {
821 	struct usb_serial_port *port = tty->driver_data;
822 	struct cypress_private *priv = usb_get_serial_port_data(port);
823 	__u8 status, control;
824 	unsigned int result = 0;
825 	unsigned long flags;
826 
827 	spin_lock_irqsave(&priv->lock, flags);
828 	control = priv->line_control;
829 	status = priv->current_status;
830 	spin_unlock_irqrestore(&priv->lock, flags);
831 
832 	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
833 		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
834 		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
835 		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
836 		| ((status & UART_RI)         ? TIOCM_RI  : 0)
837 		| ((status & UART_CD)         ? TIOCM_CD  : 0);
838 
839 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
840 
841 	return result;
842 }
843 
844 
845 static int cypress_tiocmset(struct tty_struct *tty,
846 			       unsigned int set, unsigned int clear)
847 {
848 	struct usb_serial_port *port = tty->driver_data;
849 	struct cypress_private *priv = usb_get_serial_port_data(port);
850 	unsigned long flags;
851 
852 	spin_lock_irqsave(&priv->lock, flags);
853 	if (set & TIOCM_RTS)
854 		priv->line_control |= CONTROL_RTS;
855 	if (set & TIOCM_DTR)
856 		priv->line_control |= CONTROL_DTR;
857 	if (clear & TIOCM_RTS)
858 		priv->line_control &= ~CONTROL_RTS;
859 	if (clear & TIOCM_DTR)
860 		priv->line_control &= ~CONTROL_DTR;
861 	priv->cmd_ctrl = 1;
862 	spin_unlock_irqrestore(&priv->lock, flags);
863 
864 	return cypress_write(tty, port, NULL, 0);
865 }
866 
867 
868 static int cypress_tiocmiwait(struct tty_struct *tty, unsigned long arg)
869 {
870 	struct usb_serial_port *port = tty->driver_data;
871 	struct cypress_private *priv = usb_get_serial_port_data(port);
872 	char diff;
873 
874 	for (;;) {
875 		interruptible_sleep_on(&port->port.delta_msr_wait);
876 		/* see if a signal did it */
877 		if (signal_pending(current))
878 			return -ERESTARTSYS;
879 
880 		if (port->serial->disconnected)
881 			return -EIO;
882 
883 		diff = priv->diff_status;
884 		if (diff == 0)
885 			return -EIO; /* no change => error */
886 
887 		/* consume all events */
888 		priv->diff_status = 0;
889 
890 		/* return 0 if caller wanted to know about
891 		   these bits */
892 		if (((arg & TIOCM_RNG) && (diff & UART_RI))  ||
893 			((arg & TIOCM_DSR) && (diff & UART_DSR)) ||
894 			((arg & TIOCM_CD)  && (diff & UART_CD))  ||
895 			((arg & TIOCM_CTS) && (diff & UART_CTS)))
896 			return 0;
897 		/* otherwise caller can't care less about what
898 		 * happened, and so we continue to wait for
899 		 * more events.
900 		 */
901 	}
902 
903 	return 0;
904 }
905 
906 static void cypress_set_termios(struct tty_struct *tty,
907 	struct usb_serial_port *port, struct ktermios *old_termios)
908 {
909 	struct cypress_private *priv = usb_get_serial_port_data(port);
910 	struct device *dev = &port->dev;
911 	int data_bits, stop_bits, parity_type, parity_enable;
912 	unsigned cflag, iflag;
913 	unsigned long flags;
914 	__u8 oldlines;
915 	int linechange = 0;
916 
917 	spin_lock_irqsave(&priv->lock, flags);
918 	/* We can't clean this one up as we don't know the device type
919 	   early enough */
920 	if (!priv->termios_initialized) {
921 		if (priv->chiptype == CT_EARTHMATE) {
922 			tty->termios = tty_std_termios;
923 			tty->termios.c_cflag = B4800 | CS8 | CREAD | HUPCL |
924 				CLOCAL;
925 			tty->termios.c_ispeed = 4800;
926 			tty->termios.c_ospeed = 4800;
927 		} else if (priv->chiptype == CT_CYPHIDCOM) {
928 			tty->termios = tty_std_termios;
929 			tty->termios.c_cflag = B9600 | CS8 | CREAD | HUPCL |
930 				CLOCAL;
931 			tty->termios.c_ispeed = 9600;
932 			tty->termios.c_ospeed = 9600;
933 		} else if (priv->chiptype == CT_CA42V2) {
934 			tty->termios = tty_std_termios;
935 			tty->termios.c_cflag = B9600 | CS8 | CREAD | HUPCL |
936 				CLOCAL;
937 			tty->termios.c_ispeed = 9600;
938 			tty->termios.c_ospeed = 9600;
939 		}
940 		priv->termios_initialized = 1;
941 	}
942 	spin_unlock_irqrestore(&priv->lock, flags);
943 
944 	/* Unsupported features need clearing */
945 	tty->termios.c_cflag &= ~(CMSPAR|CRTSCTS);
946 
947 	cflag = tty->termios.c_cflag;
948 	iflag = tty->termios.c_iflag;
949 
950 	/* check if there are new settings */
951 	if (old_termios) {
952 		spin_lock_irqsave(&priv->lock, flags);
953 		priv->tmp_termios = tty->termios;
954 		spin_unlock_irqrestore(&priv->lock, flags);
955 	}
956 
957 	/* set number of data bits, parity, stop bits */
958 	/* when parity is disabled the parity type bit is ignored */
959 
960 	/* 1 means 2 stop bits, 0 means 1 stop bit */
961 	stop_bits = cflag & CSTOPB ? 1 : 0;
962 
963 	if (cflag & PARENB) {
964 		parity_enable = 1;
965 		/* 1 means odd parity, 0 means even parity */
966 		parity_type = cflag & PARODD ? 1 : 0;
967 	} else
968 		parity_enable = parity_type = 0;
969 
970 	switch (cflag & CSIZE) {
971 	case CS5:
972 		data_bits = 0;
973 		break;
974 	case CS6:
975 		data_bits = 1;
976 		break;
977 	case CS7:
978 		data_bits = 2;
979 		break;
980 	case CS8:
981 		data_bits = 3;
982 		break;
983 	default:
984 		dev_err(dev, "%s - CSIZE was set, but not CS5-CS8\n", __func__);
985 		data_bits = 3;
986 	}
987 	spin_lock_irqsave(&priv->lock, flags);
988 	oldlines = priv->line_control;
989 	if ((cflag & CBAUD) == B0) {
990 		/* drop dtr and rts */
991 		dev_dbg(dev, "%s - dropping the lines, baud rate 0bps\n", __func__);
992 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
993 	} else
994 		priv->line_control = (CONTROL_DTR | CONTROL_RTS);
995 	spin_unlock_irqrestore(&priv->lock, flags);
996 
997 	dev_dbg(dev, "%s - sending %d stop_bits, %d parity_enable, %d parity_type, %d data_bits (+5)\n",
998 		__func__, stop_bits, parity_enable, parity_type, data_bits);
999 
1000 	cypress_serial_control(tty, port, tty_get_baud_rate(tty),
1001 			data_bits, stop_bits,
1002 			parity_enable, parity_type,
1003 			0, CYPRESS_SET_CONFIG);
1004 
1005 	/* we perform a CYPRESS_GET_CONFIG so that the current settings are
1006 	 * filled into the private structure this should confirm that all is
1007 	 * working if it returns what we just set */
1008 	cypress_serial_control(tty, port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
1009 
1010 	/* Here we can define custom tty settings for devices; the main tty
1011 	 * termios flag base comes from empeg.c */
1012 
1013 	spin_lock_irqsave(&priv->lock, flags);
1014 	if (priv->chiptype == CT_EARTHMATE && priv->baud_rate == 4800) {
1015 		dev_dbg(dev, "Using custom termios settings for a baud rate of 4800bps.\n");
1016 		/* define custom termios settings for NMEA protocol */
1017 
1018 		tty->termios.c_iflag /* input modes - */
1019 			&= ~(IGNBRK  /* disable ignore break */
1020 			| BRKINT     /* disable break causes interrupt */
1021 			| PARMRK     /* disable mark parity errors */
1022 			| ISTRIP     /* disable clear high bit of input char */
1023 			| INLCR      /* disable translate NL to CR */
1024 			| IGNCR      /* disable ignore CR */
1025 			| ICRNL      /* disable translate CR to NL */
1026 			| IXON);     /* disable enable XON/XOFF flow control */
1027 
1028 		tty->termios.c_oflag /* output modes */
1029 			&= ~OPOST;    /* disable postprocess output char */
1030 
1031 		tty->termios.c_lflag /* line discipline modes */
1032 			&= ~(ECHO     /* disable echo input characters */
1033 			| ECHONL      /* disable echo new line */
1034 			| ICANON      /* disable erase, kill, werase, and rprnt
1035 					 special characters */
1036 			| ISIG        /* disable interrupt, quit, and suspend
1037 					 special characters */
1038 			| IEXTEN);    /* disable non-POSIX special characters */
1039 	} /* CT_CYPHIDCOM: Application should handle this for device */
1040 
1041 	linechange = (priv->line_control != oldlines);
1042 	spin_unlock_irqrestore(&priv->lock, flags);
1043 
1044 	/* if necessary, set lines */
1045 	if (linechange) {
1046 		priv->cmd_ctrl = 1;
1047 		cypress_write(tty, port, NULL, 0);
1048 	}
1049 } /* cypress_set_termios */
1050 
1051 
1052 /* returns amount of data still left in soft buffer */
1053 static int cypress_chars_in_buffer(struct tty_struct *tty)
1054 {
1055 	struct usb_serial_port *port = tty->driver_data;
1056 	struct cypress_private *priv = usb_get_serial_port_data(port);
1057 	int chars = 0;
1058 	unsigned long flags;
1059 
1060 	spin_lock_irqsave(&priv->lock, flags);
1061 	chars = kfifo_len(&priv->write_fifo);
1062 	spin_unlock_irqrestore(&priv->lock, flags);
1063 
1064 	dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars);
1065 	return chars;
1066 }
1067 
1068 
1069 static void cypress_throttle(struct tty_struct *tty)
1070 {
1071 	struct usb_serial_port *port = tty->driver_data;
1072 	struct cypress_private *priv = usb_get_serial_port_data(port);
1073 
1074 	spin_lock_irq(&priv->lock);
1075 	priv->rx_flags = THROTTLED;
1076 	spin_unlock_irq(&priv->lock);
1077 }
1078 
1079 
1080 static void cypress_unthrottle(struct tty_struct *tty)
1081 {
1082 	struct usb_serial_port *port = tty->driver_data;
1083 	struct cypress_private *priv = usb_get_serial_port_data(port);
1084 	int actually_throttled, result;
1085 
1086 	spin_lock_irq(&priv->lock);
1087 	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
1088 	priv->rx_flags = 0;
1089 	spin_unlock_irq(&priv->lock);
1090 
1091 	if (!priv->comm_is_ok)
1092 		return;
1093 
1094 	if (actually_throttled) {
1095 		result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
1096 		if (result) {
1097 			dev_err(&port->dev, "%s - failed submitting read urb, "
1098 					"error %d\n", __func__, result);
1099 			cypress_set_dead(port);
1100 		}
1101 	}
1102 }
1103 
1104 
1105 static void cypress_read_int_callback(struct urb *urb)
1106 {
1107 	struct usb_serial_port *port = urb->context;
1108 	struct cypress_private *priv = usb_get_serial_port_data(port);
1109 	struct device *dev = &urb->dev->dev;
1110 	struct tty_struct *tty;
1111 	unsigned char *data = urb->transfer_buffer;
1112 	unsigned long flags;
1113 	char tty_flag = TTY_NORMAL;
1114 	int havedata = 0;
1115 	int bytes = 0;
1116 	int result;
1117 	int i = 0;
1118 	int status = urb->status;
1119 
1120 	switch (status) {
1121 	case 0: /* success */
1122 		break;
1123 	case -ECONNRESET:
1124 	case -ENOENT:
1125 	case -ESHUTDOWN:
1126 		/* precursor to disconnect so just go away */
1127 		return;
1128 	case -EPIPE:
1129 		/* Can't call usb_clear_halt while in_interrupt */
1130 		/* FALLS THROUGH */
1131 	default:
1132 		/* something ugly is going on... */
1133 		dev_err(dev, "%s - unexpected nonzero read status received: %d\n",
1134 			__func__, status);
1135 		cypress_set_dead(port);
1136 		return;
1137 	}
1138 
1139 	spin_lock_irqsave(&priv->lock, flags);
1140 	if (priv->rx_flags & THROTTLED) {
1141 		dev_dbg(dev, "%s - now throttling\n", __func__);
1142 		priv->rx_flags |= ACTUALLY_THROTTLED;
1143 		spin_unlock_irqrestore(&priv->lock, flags);
1144 		return;
1145 	}
1146 	spin_unlock_irqrestore(&priv->lock, flags);
1147 
1148 	tty = tty_port_tty_get(&port->port);
1149 	if (!tty) {
1150 		dev_dbg(dev, "%s - bad tty pointer - exiting\n", __func__);
1151 		return;
1152 	}
1153 
1154 	spin_lock_irqsave(&priv->lock, flags);
1155 	result = urb->actual_length;
1156 	switch (priv->pkt_fmt) {
1157 	default:
1158 	case packet_format_1:
1159 		/* This is for the CY7C64013... */
1160 		priv->current_status = data[0] & 0xF8;
1161 		bytes = data[1] + 2;
1162 		i = 2;
1163 		if (bytes > 2)
1164 			havedata = 1;
1165 		break;
1166 	case packet_format_2:
1167 		/* This is for the CY7C63743... */
1168 		priv->current_status = data[0] & 0xF8;
1169 		bytes = (data[0] & 0x07) + 1;
1170 		i = 1;
1171 		if (bytes > 1)
1172 			havedata = 1;
1173 		break;
1174 	}
1175 	spin_unlock_irqrestore(&priv->lock, flags);
1176 	if (result < bytes) {
1177 		dev_dbg(dev,
1178 			"%s - wrong packet size - received %d bytes but packet said %d bytes\n",
1179 			__func__, result, bytes);
1180 		goto continue_read;
1181 	}
1182 
1183 	usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
1184 
1185 	spin_lock_irqsave(&priv->lock, flags);
1186 	/* check to see if status has changed */
1187 	if (priv->current_status != priv->prev_status) {
1188 		priv->diff_status |= priv->current_status ^
1189 			priv->prev_status;
1190 		wake_up_interruptible(&port->port.delta_msr_wait);
1191 		priv->prev_status = priv->current_status;
1192 	}
1193 	spin_unlock_irqrestore(&priv->lock, flags);
1194 
1195 	/* hangup, as defined in acm.c... this might be a bad place for it
1196 	 * though */
1197 	if (tty && !(tty->termios.c_cflag & CLOCAL) &&
1198 			!(priv->current_status & UART_CD)) {
1199 		dev_dbg(dev, "%s - calling hangup\n", __func__);
1200 		tty_hangup(tty);
1201 		goto continue_read;
1202 	}
1203 
1204 	/* There is one error bit... I'm assuming it is a parity error
1205 	 * indicator as the generic firmware will set this bit to 1 if a
1206 	 * parity error occurs.
1207 	 * I can not find reference to any other error events. */
1208 	spin_lock_irqsave(&priv->lock, flags);
1209 	if (priv->current_status & CYP_ERROR) {
1210 		spin_unlock_irqrestore(&priv->lock, flags);
1211 		tty_flag = TTY_PARITY;
1212 		dev_dbg(dev, "%s - Parity Error detected\n", __func__);
1213 	} else
1214 		spin_unlock_irqrestore(&priv->lock, flags);
1215 
1216 	/* process read if there is data other than line status */
1217 	if (bytes > i) {
1218 		tty_insert_flip_string_fixed_flag(&port->port, data + i,
1219 				tty_flag, bytes - i);
1220 		tty_flip_buffer_push(&port->port);
1221 	}
1222 
1223 	spin_lock_irqsave(&priv->lock, flags);
1224 	/* control and status byte(s) are also counted */
1225 	priv->bytes_in += bytes;
1226 	spin_unlock_irqrestore(&priv->lock, flags);
1227 
1228 continue_read:
1229 	tty_kref_put(tty);
1230 
1231 	/* Continue trying to always read */
1232 
1233 	if (priv->comm_is_ok) {
1234 		usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1235 				usb_rcvintpipe(port->serial->dev,
1236 					port->interrupt_in_endpointAddress),
1237 				port->interrupt_in_urb->transfer_buffer,
1238 				port->interrupt_in_urb->transfer_buffer_length,
1239 				cypress_read_int_callback, port,
1240 				priv->read_urb_interval);
1241 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1242 		if (result && result != -EPERM) {
1243 			dev_err(dev, "%s - failed resubmitting read urb, error %d\n",
1244 				__func__, result);
1245 			cypress_set_dead(port);
1246 		}
1247 	}
1248 } /* cypress_read_int_callback */
1249 
1250 
1251 static void cypress_write_int_callback(struct urb *urb)
1252 {
1253 	struct usb_serial_port *port = urb->context;
1254 	struct cypress_private *priv = usb_get_serial_port_data(port);
1255 	struct device *dev = &urb->dev->dev;
1256 	int result;
1257 	int status = urb->status;
1258 
1259 	switch (status) {
1260 	case 0:
1261 		/* success */
1262 		break;
1263 	case -ECONNRESET:
1264 	case -ENOENT:
1265 	case -ESHUTDOWN:
1266 		/* this urb is terminated, clean up */
1267 		dev_dbg(dev, "%s - urb shutting down with status: %d\n",
1268 			__func__, status);
1269 		priv->write_urb_in_use = 0;
1270 		return;
1271 	case -EPIPE: /* no break needed; clear halt and resubmit */
1272 		if (!priv->comm_is_ok)
1273 			break;
1274 		usb_clear_halt(port->serial->dev, 0x02);
1275 		/* error in the urb, so we have to resubmit it */
1276 		dev_dbg(dev, "%s - nonzero write bulk status received: %d\n",
1277 			__func__, status);
1278 		port->interrupt_out_urb->transfer_buffer_length = 1;
1279 		result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
1280 		if (!result)
1281 			return;
1282 		dev_err(dev, "%s - failed resubmitting write urb, error %d\n",
1283 			__func__, result);
1284 		cypress_set_dead(port);
1285 		break;
1286 	default:
1287 		dev_err(dev, "%s - unexpected nonzero write status received: %d\n",
1288 			__func__, status);
1289 		cypress_set_dead(port);
1290 		break;
1291 	}
1292 	priv->write_urb_in_use = 0;
1293 
1294 	/* send any buffered data */
1295 	cypress_send(port);
1296 }
1297 
1298 module_usb_serial_driver(serial_drivers, id_table_combined);
1299 
1300 MODULE_AUTHOR(DRIVER_AUTHOR);
1301 MODULE_DESCRIPTION(DRIVER_DESC);
1302 MODULE_LICENSE("GPL");
1303 
1304 module_param(stats, bool, S_IRUGO | S_IWUSR);
1305 MODULE_PARM_DESC(stats, "Enable statistics or not");
1306 module_param(interval, int, S_IRUGO | S_IWUSR);
1307 MODULE_PARM_DESC(interval, "Overrides interrupt interval");
1308 module_param(unstable_bauds, bool, S_IRUGO | S_IWUSR);
1309 MODULE_PARM_DESC(unstable_bauds, "Allow unstable baud rates");
1310