xref: /linux/drivers/usb/serial/cypress_m8.c (revision 7056741fd9fc14a65608549a4657cf5178f05f63)
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 /*
54  * Version Information
55  */
56 #define DRIVER_VERSION "v1.10"
57 #define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
58 #define DRIVER_DESC "Cypress USB to Serial Driver"
59 
60 /* write buffer size defines */
61 #define CYPRESS_BUF_SIZE	1024
62 
63 static const struct usb_device_id id_table_earthmate[] = {
64 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
65 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
66 	{ }						/* Terminating entry */
67 };
68 
69 static const struct usb_device_id id_table_cyphidcomrs232[] = {
70 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
71 	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
72 	{ }						/* Terminating entry */
73 };
74 
75 static const struct usb_device_id id_table_nokiaca42v2[] = {
76 	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
77 	{ }						/* Terminating entry */
78 };
79 
80 static const struct usb_device_id id_table_combined[] = {
81 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
82 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
83 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
84 	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
85 	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
86 	{ }						/* Terminating entry */
87 };
88 
89 MODULE_DEVICE_TABLE(usb, id_table_combined);
90 
91 enum packet_format {
92 	packet_format_1,  /* b0:status, b1:payload count */
93 	packet_format_2   /* b0[7:3]:status, b0[2:0]:payload count */
94 };
95 
96 struct cypress_private {
97 	spinlock_t lock;		   /* private lock */
98 	int chiptype;			   /* identifier of device, for quirks/etc */
99 	int bytes_in;			   /* used for statistics */
100 	int bytes_out;			   /* used for statistics */
101 	int cmd_count;			   /* used for statistics */
102 	int cmd_ctrl;			   /* always set this to 1 before issuing a command */
103 	struct kfifo write_fifo;	   /* write fifo */
104 	int write_urb_in_use;		   /* write urb in use indicator */
105 	int write_urb_interval;            /* interval to use for write urb */
106 	int read_urb_interval;             /* interval to use for read urb */
107 	int comm_is_ok;                    /* true if communication is (still) ok */
108 	int termios_initialized;
109 	__u8 line_control;	   	   /* holds dtr / rts value */
110 	__u8 current_status;	   	   /* received from last read - info on dsr,cts,cd,ri,etc */
111 	__u8 current_config;	   	   /* stores the current configuration byte */
112 	__u8 rx_flags;			   /* throttling - used from whiteheat/ftdi_sio */
113 	enum packet_format pkt_fmt;	   /* format to use for packet send / receive */
114 	int get_cfg_unsafe;		   /* If true, the CYPRESS_GET_CONFIG is unsafe */
115 	int baud_rate;			   /* stores current baud rate in
116 					      integer form */
117 	int isthrottled;		   /* if throttled, discard reads */
118 	wait_queue_head_t delta_msr_wait;  /* used for TIOCMIWAIT */
119 	char prev_status, diff_status;	   /* used for TIOCMIWAIT */
120 	/* we pass a pointer to this as the argument sent to
121 	   cypress_set_termios old_termios */
122 	struct ktermios tmp_termios; 	   /* stores the old termios settings */
123 };
124 
125 /* function prototypes for the Cypress USB to serial device */
126 static int  cypress_earthmate_startup(struct usb_serial *serial);
127 static int  cypress_hidcom_startup(struct usb_serial *serial);
128 static int  cypress_ca42v2_startup(struct usb_serial *serial);
129 static void cypress_release(struct usb_serial *serial);
130 static int  cypress_open(struct tty_struct *tty, struct usb_serial_port *port);
131 static void cypress_close(struct usb_serial_port *port);
132 static void cypress_dtr_rts(struct usb_serial_port *port, int on);
133 static int  cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
134 			const unsigned char *buf, int count);
135 static void cypress_send(struct usb_serial_port *port);
136 static int  cypress_write_room(struct tty_struct *tty);
137 static int  cypress_ioctl(struct tty_struct *tty,
138 			unsigned int cmd, unsigned long arg);
139 static void cypress_set_termios(struct tty_struct *tty,
140 			struct usb_serial_port *port, struct ktermios *old);
141 static int  cypress_tiocmget(struct tty_struct *tty);
142 static int  cypress_tiocmset(struct tty_struct *tty,
143 			unsigned int set, unsigned int clear);
144 static int  cypress_chars_in_buffer(struct tty_struct *tty);
145 static void cypress_throttle(struct tty_struct *tty);
146 static void cypress_unthrottle(struct tty_struct *tty);
147 static void cypress_set_dead(struct usb_serial_port *port);
148 static void cypress_read_int_callback(struct urb *urb);
149 static void cypress_write_int_callback(struct urb *urb);
150 
151 static struct usb_serial_driver cypress_earthmate_device = {
152 	.driver = {
153 		.owner =		THIS_MODULE,
154 		.name =			"earthmate",
155 	},
156 	.description =			"DeLorme Earthmate USB",
157 	.id_table =			id_table_earthmate,
158 	.num_ports =			1,
159 	.attach =			cypress_earthmate_startup,
160 	.release =			cypress_release,
161 	.open =				cypress_open,
162 	.close =			cypress_close,
163 	.dtr_rts =			cypress_dtr_rts,
164 	.write =			cypress_write,
165 	.write_room =			cypress_write_room,
166 	.ioctl =			cypress_ioctl,
167 	.set_termios =			cypress_set_termios,
168 	.tiocmget =			cypress_tiocmget,
169 	.tiocmset =			cypress_tiocmset,
170 	.chars_in_buffer =		cypress_chars_in_buffer,
171 	.throttle =		 	cypress_throttle,
172 	.unthrottle =			cypress_unthrottle,
173 	.read_int_callback =		cypress_read_int_callback,
174 	.write_int_callback =		cypress_write_int_callback,
175 };
176 
177 static struct usb_serial_driver cypress_hidcom_device = {
178 	.driver = {
179 		.owner =		THIS_MODULE,
180 		.name =			"cyphidcom",
181 	},
182 	.description =			"HID->COM RS232 Adapter",
183 	.id_table =			id_table_cyphidcomrs232,
184 	.num_ports =			1,
185 	.attach =			cypress_hidcom_startup,
186 	.release =			cypress_release,
187 	.open =				cypress_open,
188 	.close =			cypress_close,
189 	.dtr_rts =			cypress_dtr_rts,
190 	.write =			cypress_write,
191 	.write_room =			cypress_write_room,
192 	.ioctl =			cypress_ioctl,
193 	.set_termios =			cypress_set_termios,
194 	.tiocmget =			cypress_tiocmget,
195 	.tiocmset =			cypress_tiocmset,
196 	.chars_in_buffer =		cypress_chars_in_buffer,
197 	.throttle =			cypress_throttle,
198 	.unthrottle =			cypress_unthrottle,
199 	.read_int_callback =		cypress_read_int_callback,
200 	.write_int_callback =		cypress_write_int_callback,
201 };
202 
203 static struct usb_serial_driver cypress_ca42v2_device = {
204 	.driver = {
205 		.owner =		THIS_MODULE,
206 		.name =			"nokiaca42v2",
207 	},
208 	.description =			"Nokia CA-42 V2 Adapter",
209 	.id_table =			id_table_nokiaca42v2,
210 	.num_ports =			1,
211 	.attach =			cypress_ca42v2_startup,
212 	.release =			cypress_release,
213 	.open =				cypress_open,
214 	.close =			cypress_close,
215 	.dtr_rts =			cypress_dtr_rts,
216 	.write =			cypress_write,
217 	.write_room =			cypress_write_room,
218 	.ioctl =			cypress_ioctl,
219 	.set_termios =			cypress_set_termios,
220 	.tiocmget =			cypress_tiocmget,
221 	.tiocmset =			cypress_tiocmset,
222 	.chars_in_buffer =		cypress_chars_in_buffer,
223 	.throttle =			cypress_throttle,
224 	.unthrottle =			cypress_unthrottle,
225 	.read_int_callback =		cypress_read_int_callback,
226 	.write_int_callback =		cypress_write_int_callback,
227 };
228 
229 static struct usb_serial_driver * const serial_drivers[] = {
230 	&cypress_earthmate_device, &cypress_hidcom_device,
231 	&cypress_ca42v2_device, NULL
232 };
233 
234 /*****************************************************************************
235  * Cypress serial helper functions
236  *****************************************************************************/
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 	/*
248 	 * The general purpose firmware for the Cypress M8 allows for
249 	 * a maximum speed of 57600bps (I have no idea whether DeLorme
250 	 * chose to use the general purpose firmware or not), if you
251 	 * need to modify this speed setting for your own project
252 	 * please add your own chiptype and modify the code likewise.
253 	 * The Cypress HID->COM device will work successfully up to
254 	 * 115200bps (but the actual throughput is around 3kBps).
255 	 */
256 	if (port->serial->dev->speed == USB_SPEED_LOW) {
257 		/*
258 		 * Mike Isely <isely@pobox.com> 2-Feb-2008: The
259 		 * Cypress app note that describes this mechanism
260 		 * states the the low-speed part can't handle more
261 		 * than 800 bytes/sec, in which case 4800 baud is the
262 		 * safest speed for a part like that.
263 		 */
264 		if (new_rate > 4800) {
265 			dev_dbg(&port->dev,
266 				"%s - failed setting baud rate, device incapable speed %d\n",
267 				__func__, new_rate);
268 			return -1;
269 		}
270 	}
271 	switch (priv->chiptype) {
272 	case CT_EARTHMATE:
273 		if (new_rate <= 600) {
274 			/* 300 and 600 baud rates are supported under
275 			 * the generic firmware, but are not used with
276 			 * NMEA and SiRF protocols */
277 			dev_dbg(&port->dev,
278 				"%s - failed setting baud rate, unsupported speed of %d on Earthmate GPS",
279 				__func__, new_rate);
280 			return -1;
281 		}
282 		break;
283 	default:
284 		break;
285 	}
286 	return new_rate;
287 }
288 
289 
290 /* This function can either set or retrieve the current serial line settings */
291 static int cypress_serial_control(struct tty_struct *tty,
292 	struct usb_serial_port *port, speed_t baud_rate, int data_bits,
293 	int stop_bits, int parity_enable, int parity_type, int reset,
294 	int cypress_request_type)
295 {
296 	int new_baudrate = 0, retval = 0, tries = 0;
297 	struct cypress_private *priv;
298 	struct device *dev = &port->dev;
299 	u8 *feature_buffer;
300 	const unsigned int feature_len = 5;
301 	unsigned long flags;
302 
303 	priv = usb_get_serial_port_data(port);
304 
305 	if (!priv->comm_is_ok)
306 		return -ENODEV;
307 
308 	feature_buffer = kcalloc(feature_len, sizeof(u8), GFP_KERNEL);
309 	if (!feature_buffer)
310 		return -ENOMEM;
311 
312 	switch (cypress_request_type) {
313 	case CYPRESS_SET_CONFIG:
314 		/* 0 means 'Hang up' so doesn't change the true bit rate */
315 		new_baudrate = priv->baud_rate;
316 		if (baud_rate && baud_rate != priv->baud_rate) {
317 			dev_dbg(dev, "%s - baud rate is changing\n", __func__);
318 			retval = analyze_baud_rate(port, baud_rate);
319 			if (retval >= 0) {
320 				new_baudrate = retval;
321 				dev_dbg(dev, "%s - New baud rate set to %d\n",
322 					__func__, new_baudrate);
323 			}
324 		}
325 		dev_dbg(dev, "%s - baud rate is being sent as %d\n", __func__,
326 			new_baudrate);
327 
328 		/* fill the feature_buffer with new configuration */
329 		put_unaligned_le32(new_baudrate, feature_buffer);
330 		feature_buffer[4] |= data_bits;   /* assign data bits in 2 bit space ( max 3 ) */
331 		/* 1 bit gap */
332 		feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
333 		feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
334 		feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
335 		/* 1 bit gap */
336 		feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
337 
338 		dev_dbg(dev, "%s - device is being sent this feature report:\n", __func__);
339 		dev_dbg(dev, "%s - %02X - %02X - %02X - %02X - %02X\n", __func__,
340 			feature_buffer[0], feature_buffer[1],
341 			feature_buffer[2], feature_buffer[3],
342 			feature_buffer[4]);
343 
344 		do {
345 			retval = usb_control_msg(port->serial->dev,
346 					usb_sndctrlpipe(port->serial->dev, 0),
347 					HID_REQ_SET_REPORT,
348 					USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
349 					0x0300, 0, feature_buffer,
350 					feature_len, 500);
351 
352 			if (tries++ >= 3)
353 				break;
354 
355 		} while (retval != feature_len &&
356 			 retval != -ENODEV);
357 
358 		if (retval != feature_len) {
359 			dev_err(dev, "%s - failed sending serial line settings - %d\n",
360 				__func__, retval);
361 			cypress_set_dead(port);
362 		} else {
363 			spin_lock_irqsave(&priv->lock, flags);
364 			priv->baud_rate = new_baudrate;
365 			priv->current_config = feature_buffer[4];
366 			spin_unlock_irqrestore(&priv->lock, flags);
367 			/* If we asked for a speed change encode it */
368 			if (baud_rate)
369 				tty_encode_baud_rate(tty,
370 					new_baudrate, new_baudrate);
371 		}
372 	break;
373 	case CYPRESS_GET_CONFIG:
374 		if (priv->get_cfg_unsafe) {
375 			/* Not implemented for this device,
376 			   and if we try to do it we're likely
377 			   to crash the hardware. */
378 			retval = -ENOTTY;
379 			goto out;
380 		}
381 		dev_dbg(dev, "%s - retreiving serial line settings\n", __func__);
382 		do {
383 			retval = usb_control_msg(port->serial->dev,
384 					usb_rcvctrlpipe(port->serial->dev, 0),
385 					HID_REQ_GET_REPORT,
386 					USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
387 					0x0300, 0, feature_buffer,
388 					feature_len, 500);
389 
390 			if (tries++ >= 3)
391 				break;
392 		} while (retval != feature_len
393 						&& retval != -ENODEV);
394 
395 		if (retval != feature_len) {
396 			dev_err(dev, "%s - failed to retrieve serial line settings - %d\n",
397 				__func__, retval);
398 			cypress_set_dead(port);
399 			goto out;
400 		} else {
401 			spin_lock_irqsave(&priv->lock, flags);
402 			/* store the config in one byte, and later
403 			   use bit masks to check values */
404 			priv->current_config = feature_buffer[4];
405 			priv->baud_rate = get_unaligned_le32(feature_buffer);
406 			spin_unlock_irqrestore(&priv->lock, flags);
407 		}
408 	}
409 	spin_lock_irqsave(&priv->lock, flags);
410 	++priv->cmd_count;
411 	spin_unlock_irqrestore(&priv->lock, flags);
412 out:
413 	kfree(feature_buffer);
414 	return retval;
415 } /* cypress_serial_control */
416 
417 
418 static void cypress_set_dead(struct usb_serial_port *port)
419 {
420 	struct cypress_private *priv = usb_get_serial_port_data(port);
421 	unsigned long flags;
422 
423 	spin_lock_irqsave(&priv->lock, flags);
424 	if (!priv->comm_is_ok) {
425 		spin_unlock_irqrestore(&priv->lock, flags);
426 		return;
427 	}
428 	priv->comm_is_ok = 0;
429 	spin_unlock_irqrestore(&priv->lock, flags);
430 
431 	dev_err(&port->dev, "cypress_m8 suspending failing port %d - "
432 		"interval might be too short\n", port->number);
433 }
434 
435 
436 /*****************************************************************************
437  * Cypress serial driver functions
438  *****************************************************************************/
439 
440 
441 static int generic_startup(struct usb_serial *serial)
442 {
443 	struct cypress_private *priv;
444 	struct usb_serial_port *port = serial->port[0];
445 
446 	priv = kzalloc(sizeof(struct cypress_private), GFP_KERNEL);
447 	if (!priv)
448 		return -ENOMEM;
449 
450 	priv->comm_is_ok = !0;
451 	spin_lock_init(&priv->lock);
452 	if (kfifo_alloc(&priv->write_fifo, CYPRESS_BUF_SIZE, GFP_KERNEL)) {
453 		kfree(priv);
454 		return -ENOMEM;
455 	}
456 	init_waitqueue_head(&priv->delta_msr_wait);
457 
458 	usb_reset_configuration(serial->dev);
459 
460 	priv->cmd_ctrl = 0;
461 	priv->line_control = 0;
462 	priv->termios_initialized = 0;
463 	priv->rx_flags = 0;
464 	/* Default packet format setting is determined by packet size.
465 	   Anything with a size larger then 9 must have a separate
466 	   count field since the 3 bit count field is otherwise too
467 	   small.  Otherwise we can use the slightly more compact
468 	   format.  This is in accordance with the cypress_m8 serial
469 	   converter app note. */
470 	if (port->interrupt_out_size > 9)
471 		priv->pkt_fmt = packet_format_1;
472 	else
473 		priv->pkt_fmt = packet_format_2;
474 
475 	if (interval > 0) {
476 		priv->write_urb_interval = interval;
477 		priv->read_urb_interval = interval;
478 		dev_dbg(&port->dev, "%s - read & write intervals forced to %d\n",
479 			__func__, interval);
480 	} else {
481 		priv->write_urb_interval = port->interrupt_out_urb->interval;
482 		priv->read_urb_interval = port->interrupt_in_urb->interval;
483 		dev_dbg(&port->dev, "%s - intervals: read=%d write=%d\n",
484 			__func__, priv->read_urb_interval,
485 			priv->write_urb_interval);
486 	}
487 	usb_set_serial_port_data(port, priv);
488 
489 	return 0;
490 }
491 
492 
493 static int cypress_earthmate_startup(struct usb_serial *serial)
494 {
495 	struct cypress_private *priv;
496 	struct usb_serial_port *port = serial->port[0];
497 
498 	if (generic_startup(serial)) {
499 		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
500 		return 1;
501 	}
502 
503 	priv = usb_get_serial_port_data(port);
504 	priv->chiptype = CT_EARTHMATE;
505 	/* All Earthmate devices use the separated-count packet
506 	   format!  Idiotic. */
507 	priv->pkt_fmt = packet_format_1;
508 	if (serial->dev->descriptor.idProduct !=
509 				cpu_to_le16(PRODUCT_ID_EARTHMATEUSB)) {
510 		/* The old original USB Earthmate seemed able to
511 		   handle GET_CONFIG requests; everything they've
512 		   produced since that time crashes if this command is
513 		   attempted :-( */
514 		dev_dbg(&port->dev,
515 			"%s - Marking this device as unsafe for GET_CONFIG commands\n",
516 			__func__);
517 		priv->get_cfg_unsafe = !0;
518 	}
519 
520 	return 0;
521 } /* cypress_earthmate_startup */
522 
523 
524 static int cypress_hidcom_startup(struct usb_serial *serial)
525 {
526 	struct cypress_private *priv;
527 	struct usb_serial_port *port = serial->port[0];
528 
529 	if (generic_startup(serial)) {
530 		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
531 		return 1;
532 	}
533 
534 	priv = usb_get_serial_port_data(port);
535 	priv->chiptype = CT_CYPHIDCOM;
536 
537 	return 0;
538 } /* cypress_hidcom_startup */
539 
540 
541 static int cypress_ca42v2_startup(struct usb_serial *serial)
542 {
543 	struct cypress_private *priv;
544 	struct usb_serial_port *port = serial->port[0];
545 
546 	if (generic_startup(serial)) {
547 		dev_dbg(&port->dev, "%s - Failed setting up port\n", __func__);
548 		return 1;
549 	}
550 
551 	priv = usb_get_serial_port_data(port);
552 	priv->chiptype = CT_CA42V2;
553 
554 	return 0;
555 } /* cypress_ca42v2_startup */
556 
557 
558 static void cypress_release(struct usb_serial *serial)
559 {
560 	struct cypress_private *priv;
561 
562 	/* all open ports are closed at this point */
563 	priv = usb_get_serial_port_data(serial->port[0]);
564 
565 	if (priv) {
566 		kfifo_free(&priv->write_fifo);
567 		kfree(priv);
568 	}
569 }
570 
571 
572 static int cypress_open(struct tty_struct *tty, struct usb_serial_port *port)
573 {
574 	struct cypress_private *priv = usb_get_serial_port_data(port);
575 	struct usb_serial *serial = port->serial;
576 	unsigned long flags;
577 	int result = 0;
578 
579 	if (!priv->comm_is_ok)
580 		return -EIO;
581 
582 	/* clear halts before open */
583 	usb_clear_halt(serial->dev, 0x81);
584 	usb_clear_halt(serial->dev, 0x02);
585 
586 	spin_lock_irqsave(&priv->lock, flags);
587 	/* reset read/write statistics */
588 	priv->bytes_in = 0;
589 	priv->bytes_out = 0;
590 	priv->cmd_count = 0;
591 	priv->rx_flags = 0;
592 	spin_unlock_irqrestore(&priv->lock, flags);
593 
594 	/* Set termios */
595 	cypress_send(port);
596 
597 	if (tty)
598 		cypress_set_termios(tty, port, &priv->tmp_termios);
599 
600 	/* setup the port and start reading from the device */
601 	if (!port->interrupt_in_urb) {
602 		dev_err(&port->dev, "%s - interrupt_in_urb is empty!\n",
603 			__func__);
604 		return -1;
605 	}
606 
607 	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
608 		usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
609 		port->interrupt_in_urb->transfer_buffer,
610 		port->interrupt_in_urb->transfer_buffer_length,
611 		cypress_read_int_callback, port, priv->read_urb_interval);
612 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
613 
614 	if (result) {
615 		dev_err(&port->dev,
616 			"%s - failed submitting read urb, error %d\n",
617 							__func__, result);
618 		cypress_set_dead(port);
619 	}
620 	port->port.drain_delay = 256;
621 	return result;
622 } /* cypress_open */
623 
624 static void cypress_dtr_rts(struct usb_serial_port *port, int on)
625 {
626 	struct cypress_private *priv = usb_get_serial_port_data(port);
627 	/* drop dtr and rts */
628 	spin_lock_irq(&priv->lock);
629 	if (on == 0)
630 		priv->line_control = 0;
631 	else
632 		priv->line_control = CONTROL_DTR | CONTROL_RTS;
633 	priv->cmd_ctrl = 1;
634 	spin_unlock_irq(&priv->lock);
635 	cypress_write(NULL, port, NULL, 0);
636 }
637 
638 static void cypress_close(struct usb_serial_port *port)
639 {
640 	struct cypress_private *priv = usb_get_serial_port_data(port);
641 	unsigned long flags;
642 
643 	/* writing is potentially harmful, lock must be taken */
644 	mutex_lock(&port->serial->disc_mutex);
645 	if (port->serial->disconnected) {
646 		mutex_unlock(&port->serial->disc_mutex);
647 		return;
648 	}
649 	spin_lock_irqsave(&priv->lock, flags);
650 	kfifo_reset_out(&priv->write_fifo);
651 	spin_unlock_irqrestore(&priv->lock, flags);
652 
653 	dev_dbg(&port->dev, "%s - stopping urbs\n", __func__);
654 	usb_kill_urb(port->interrupt_in_urb);
655 	usb_kill_urb(port->interrupt_out_urb);
656 
657 	if (stats)
658 		dev_info(&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
659 			priv->bytes_in, priv->bytes_out, priv->cmd_count);
660 	mutex_unlock(&port->serial->disc_mutex);
661 } /* cypress_close */
662 
663 
664 static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
665 					const unsigned char *buf, int count)
666 {
667 	struct cypress_private *priv = usb_get_serial_port_data(port);
668 
669 	dev_dbg(&port->dev, "%s - port %d, %d bytes\n", __func__, port->number, count);
670 
671 	/* line control commands, which need to be executed immediately,
672 	   are not put into the buffer for obvious reasons.
673 	 */
674 	if (priv->cmd_ctrl) {
675 		count = 0;
676 		goto finish;
677 	}
678 
679 	if (!count)
680 		return count;
681 
682 	count = kfifo_in_locked(&priv->write_fifo, buf, count, &priv->lock);
683 
684 finish:
685 	cypress_send(port);
686 
687 	return count;
688 } /* cypress_write */
689 
690 
691 static void cypress_send(struct usb_serial_port *port)
692 {
693 	int count = 0, result, offset, actual_size;
694 	struct cypress_private *priv = usb_get_serial_port_data(port);
695 	struct device *dev = &port->dev;
696 	unsigned long flags;
697 
698 	if (!priv->comm_is_ok)
699 		return;
700 
701 	dev_dbg(dev, "%s - interrupt out size is %d\n", __func__,
702 		port->interrupt_out_size);
703 
704 	spin_lock_irqsave(&priv->lock, flags);
705 	if (priv->write_urb_in_use) {
706 		dev_dbg(dev, "%s - can't write, urb in use\n", __func__);
707 		spin_unlock_irqrestore(&priv->lock, flags);
708 		return;
709 	}
710 	spin_unlock_irqrestore(&priv->lock, flags);
711 
712 	/* clear buffer */
713 	memset(port->interrupt_out_urb->transfer_buffer, 0,
714 						port->interrupt_out_size);
715 
716 	spin_lock_irqsave(&priv->lock, flags);
717 	switch (priv->pkt_fmt) {
718 	default:
719 	case packet_format_1:
720 		/* this is for the CY7C64013... */
721 		offset = 2;
722 		port->interrupt_out_buffer[0] = priv->line_control;
723 		break;
724 	case packet_format_2:
725 		/* this is for the CY7C63743... */
726 		offset = 1;
727 		port->interrupt_out_buffer[0] = priv->line_control;
728 		break;
729 	}
730 
731 	if (priv->line_control & CONTROL_RESET)
732 		priv->line_control &= ~CONTROL_RESET;
733 
734 	if (priv->cmd_ctrl) {
735 		priv->cmd_count++;
736 		dev_dbg(dev, "%s - line control command being issued\n", __func__);
737 		spin_unlock_irqrestore(&priv->lock, flags);
738 		goto send;
739 	} else
740 		spin_unlock_irqrestore(&priv->lock, flags);
741 
742 	count = kfifo_out_locked(&priv->write_fifo,
743 					&port->interrupt_out_buffer[offset],
744 					port->interrupt_out_size - offset,
745 					&priv->lock);
746 	if (count == 0)
747 		return;
748 
749 	switch (priv->pkt_fmt) {
750 	default:
751 	case packet_format_1:
752 		port->interrupt_out_buffer[1] = count;
753 		break;
754 	case packet_format_2:
755 		port->interrupt_out_buffer[0] |= count;
756 	}
757 
758 	dev_dbg(dev, "%s - count is %d\n", __func__, count);
759 
760 send:
761 	spin_lock_irqsave(&priv->lock, flags);
762 	priv->write_urb_in_use = 1;
763 	spin_unlock_irqrestore(&priv->lock, flags);
764 
765 	if (priv->cmd_ctrl)
766 		actual_size = 1;
767 	else
768 		actual_size = count +
769 			      (priv->pkt_fmt == packet_format_1 ? 2 : 1);
770 
771 	usb_serial_debug_data(dev, __func__, port->interrupt_out_size,
772 			      port->interrupt_out_urb->transfer_buffer);
773 
774 	usb_fill_int_urb(port->interrupt_out_urb, port->serial->dev,
775 		usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
776 		port->interrupt_out_buffer, port->interrupt_out_size,
777 		cypress_write_int_callback, port, priv->write_urb_interval);
778 	result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
779 	if (result) {
780 		dev_err_console(port,
781 				"%s - failed submitting write urb, error %d\n",
782 							__func__, result);
783 		priv->write_urb_in_use = 0;
784 		cypress_set_dead(port);
785 	}
786 
787 	spin_lock_irqsave(&priv->lock, flags);
788 	if (priv->cmd_ctrl)
789 		priv->cmd_ctrl = 0;
790 
791 	/* do not count the line control and size bytes */
792 	priv->bytes_out += count;
793 	spin_unlock_irqrestore(&priv->lock, flags);
794 
795 	usb_serial_port_softint(port);
796 } /* cypress_send */
797 
798 
799 /* returns how much space is available in the soft buffer */
800 static int cypress_write_room(struct tty_struct *tty)
801 {
802 	struct usb_serial_port *port = tty->driver_data;
803 	struct cypress_private *priv = usb_get_serial_port_data(port);
804 	int room = 0;
805 	unsigned long flags;
806 
807 	spin_lock_irqsave(&priv->lock, flags);
808 	room = kfifo_avail(&priv->write_fifo);
809 	spin_unlock_irqrestore(&priv->lock, flags);
810 
811 	dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
812 	return room;
813 }
814 
815 
816 static int cypress_tiocmget(struct tty_struct *tty)
817 {
818 	struct usb_serial_port *port = tty->driver_data;
819 	struct cypress_private *priv = usb_get_serial_port_data(port);
820 	__u8 status, control;
821 	unsigned int result = 0;
822 	unsigned long flags;
823 
824 	spin_lock_irqsave(&priv->lock, flags);
825 	control = priv->line_control;
826 	status = priv->current_status;
827 	spin_unlock_irqrestore(&priv->lock, flags);
828 
829 	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
830 		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
831 		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
832 		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
833 		| ((status & UART_RI)         ? TIOCM_RI  : 0)
834 		| ((status & UART_CD)         ? TIOCM_CD  : 0);
835 
836 	dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
837 
838 	return result;
839 }
840 
841 
842 static int cypress_tiocmset(struct tty_struct *tty,
843 			       unsigned int set, unsigned int clear)
844 {
845 	struct usb_serial_port *port = tty->driver_data;
846 	struct cypress_private *priv = usb_get_serial_port_data(port);
847 	unsigned long flags;
848 
849 	spin_lock_irqsave(&priv->lock, flags);
850 	if (set & TIOCM_RTS)
851 		priv->line_control |= CONTROL_RTS;
852 	if (set & TIOCM_DTR)
853 		priv->line_control |= CONTROL_DTR;
854 	if (clear & TIOCM_RTS)
855 		priv->line_control &= ~CONTROL_RTS;
856 	if (clear & TIOCM_DTR)
857 		priv->line_control &= ~CONTROL_DTR;
858 	priv->cmd_ctrl = 1;
859 	spin_unlock_irqrestore(&priv->lock, flags);
860 
861 	return cypress_write(tty, port, NULL, 0);
862 }
863 
864 
865 static int cypress_ioctl(struct tty_struct *tty,
866 					unsigned int cmd, unsigned long arg)
867 {
868 	struct usb_serial_port *port = tty->driver_data;
869 	struct cypress_private *priv = usb_get_serial_port_data(port);
870 
871 	dev_dbg(&port->dev, "%s - port %d, cmd 0x%.4x\n", __func__, port->number, cmd);
872 
873 	switch (cmd) {
874 	/* This code comes from drivers/char/serial.c and ftdi_sio.c */
875 	case TIOCMIWAIT:
876 		while (priv != NULL) {
877 			interruptible_sleep_on(&priv->delta_msr_wait);
878 			/* see if a signal did it */
879 			if (signal_pending(current))
880 				return -ERESTARTSYS;
881 			else {
882 				char diff = priv->diff_status;
883 				if (diff == 0)
884 					return -EIO; /* no change => error */
885 
886 				/* consume all events */
887 				priv->diff_status = 0;
888 
889 				/* return 0 if caller wanted to know about
890 				   these bits */
891 				if (((arg & TIOCM_RNG) && (diff & UART_RI)) ||
892 				    ((arg & TIOCM_DSR) && (diff & UART_DSR)) ||
893 				    ((arg & TIOCM_CD) && (diff & UART_CD)) ||
894 				    ((arg & TIOCM_CTS) && (diff & UART_CTS)))
895 					return 0;
896 				/* otherwise caller can't care less about what
897 				 * happened, and so we continue to wait for
898 				 * more events.
899 				 */
900 			}
901 		}
902 		return 0;
903 	default:
904 		break;
905 	}
906 	dev_dbg(&port->dev, "%s - arg not supported - it was 0x%04x - check include/asm/ioctls.h\n", __func__, cmd);
907 	return -ENOIOCTLCMD;
908 } /* cypress_ioctl */
909 
910 
911 static void cypress_set_termios(struct tty_struct *tty,
912 	struct usb_serial_port *port, struct ktermios *old_termios)
913 {
914 	struct cypress_private *priv = usb_get_serial_port_data(port);
915 	struct device *dev = &port->dev;
916 	int data_bits, stop_bits, parity_type, parity_enable;
917 	unsigned cflag, iflag;
918 	unsigned long flags;
919 	__u8 oldlines;
920 	int linechange = 0;
921 
922 	spin_lock_irqsave(&priv->lock, flags);
923 	/* We can't clean this one up as we don't know the device type
924 	   early enough */
925 	if (!priv->termios_initialized) {
926 		if (priv->chiptype == CT_EARTHMATE) {
927 			tty->termios = tty_std_termios;
928 			tty->termios.c_cflag = B4800 | CS8 | CREAD | HUPCL |
929 				CLOCAL;
930 			tty->termios.c_ispeed = 4800;
931 			tty->termios.c_ospeed = 4800;
932 		} else if (priv->chiptype == CT_CYPHIDCOM) {
933 			tty->termios = tty_std_termios;
934 			tty->termios.c_cflag = B9600 | CS8 | CREAD | HUPCL |
935 				CLOCAL;
936 			tty->termios.c_ispeed = 9600;
937 			tty->termios.c_ospeed = 9600;
938 		} else if (priv->chiptype == CT_CA42V2) {
939 			tty->termios = tty_std_termios;
940 			tty->termios.c_cflag = B9600 | CS8 | CREAD | HUPCL |
941 				CLOCAL;
942 			tty->termios.c_ispeed = 9600;
943 			tty->termios.c_ospeed = 9600;
944 		}
945 		priv->termios_initialized = 1;
946 	}
947 	spin_unlock_irqrestore(&priv->lock, flags);
948 
949 	/* Unsupported features need clearing */
950 	tty->termios.c_cflag &= ~(CMSPAR|CRTSCTS);
951 
952 	cflag = tty->termios.c_cflag;
953 	iflag = tty->termios.c_iflag;
954 
955 	/* check if there are new settings */
956 	if (old_termios) {
957 		spin_lock_irqsave(&priv->lock, flags);
958 		priv->tmp_termios = tty->termios;
959 		spin_unlock_irqrestore(&priv->lock, flags);
960 	}
961 
962 	/* set number of data bits, parity, stop bits */
963 	/* when parity is disabled the parity type bit is ignored */
964 
965 	/* 1 means 2 stop bits, 0 means 1 stop bit */
966 	stop_bits = cflag & CSTOPB ? 1 : 0;
967 
968 	if (cflag & PARENB) {
969 		parity_enable = 1;
970 		/* 1 means odd parity, 0 means even parity */
971 		parity_type = cflag & PARODD ? 1 : 0;
972 	} else
973 		parity_enable = parity_type = 0;
974 
975 	switch (cflag & CSIZE) {
976 	case CS5:
977 		data_bits = 0;
978 		break;
979 	case CS6:
980 		data_bits = 1;
981 		break;
982 	case CS7:
983 		data_bits = 2;
984 		break;
985 	case CS8:
986 		data_bits = 3;
987 		break;
988 	default:
989 		dev_err(dev, "%s - CSIZE was set, but not CS5-CS8\n", __func__);
990 		data_bits = 3;
991 	}
992 	spin_lock_irqsave(&priv->lock, flags);
993 	oldlines = priv->line_control;
994 	if ((cflag & CBAUD) == B0) {
995 		/* drop dtr and rts */
996 		dev_dbg(dev, "%s - dropping the lines, baud rate 0bps\n", __func__);
997 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
998 	} else
999 		priv->line_control = (CONTROL_DTR | CONTROL_RTS);
1000 	spin_unlock_irqrestore(&priv->lock, flags);
1001 
1002 	dev_dbg(dev, "%s - sending %d stop_bits, %d parity_enable, %d parity_type, %d data_bits (+5)\n",
1003 		__func__, stop_bits, parity_enable, parity_type, data_bits);
1004 
1005 	cypress_serial_control(tty, port, tty_get_baud_rate(tty),
1006 			data_bits, stop_bits,
1007 			parity_enable, parity_type,
1008 			0, CYPRESS_SET_CONFIG);
1009 
1010 	/* we perform a CYPRESS_GET_CONFIG so that the current settings are
1011 	 * filled into the private structure this should confirm that all is
1012 	 * working if it returns what we just set */
1013 	cypress_serial_control(tty, port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
1014 
1015 	/* Here we can define custom tty settings for devices; the main tty
1016 	 * termios flag base comes from empeg.c */
1017 
1018 	spin_lock_irqsave(&priv->lock, flags);
1019 	if (priv->chiptype == CT_EARTHMATE && priv->baud_rate == 4800) {
1020 		dev_dbg(dev, "Using custom termios settings for a baud rate of 4800bps.\n");
1021 		/* define custom termios settings for NMEA protocol */
1022 
1023 		tty->termios.c_iflag /* input modes - */
1024 			&= ~(IGNBRK  /* disable ignore break */
1025 			| BRKINT     /* disable break causes interrupt */
1026 			| PARMRK     /* disable mark parity errors */
1027 			| ISTRIP     /* disable clear high bit of input char */
1028 			| INLCR      /* disable translate NL to CR */
1029 			| IGNCR      /* disable ignore CR */
1030 			| ICRNL      /* disable translate CR to NL */
1031 			| IXON);     /* disable enable XON/XOFF flow control */
1032 
1033 		tty->termios.c_oflag /* output modes */
1034 			&= ~OPOST;    /* disable postprocess output char */
1035 
1036 		tty->termios.c_lflag /* line discipline modes */
1037 			&= ~(ECHO     /* disable echo input characters */
1038 			| ECHONL      /* disable echo new line */
1039 			| ICANON      /* disable erase, kill, werase, and rprnt
1040 					 special characters */
1041 			| ISIG        /* disable interrupt, quit, and suspend
1042 					 special characters */
1043 			| IEXTEN);    /* disable non-POSIX special characters */
1044 	} /* CT_CYPHIDCOM: Application should handle this for device */
1045 
1046 	linechange = (priv->line_control != oldlines);
1047 	spin_unlock_irqrestore(&priv->lock, flags);
1048 
1049 	/* if necessary, set lines */
1050 	if (linechange) {
1051 		priv->cmd_ctrl = 1;
1052 		cypress_write(tty, port, NULL, 0);
1053 	}
1054 } /* cypress_set_termios */
1055 
1056 
1057 /* returns amount of data still left in soft buffer */
1058 static int cypress_chars_in_buffer(struct tty_struct *tty)
1059 {
1060 	struct usb_serial_port *port = tty->driver_data;
1061 	struct cypress_private *priv = usb_get_serial_port_data(port);
1062 	int chars = 0;
1063 	unsigned long flags;
1064 
1065 	spin_lock_irqsave(&priv->lock, flags);
1066 	chars = kfifo_len(&priv->write_fifo);
1067 	spin_unlock_irqrestore(&priv->lock, flags);
1068 
1069 	dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars);
1070 	return chars;
1071 }
1072 
1073 
1074 static void cypress_throttle(struct tty_struct *tty)
1075 {
1076 	struct usb_serial_port *port = tty->driver_data;
1077 	struct cypress_private *priv = usb_get_serial_port_data(port);
1078 
1079 	spin_lock_irq(&priv->lock);
1080 	priv->rx_flags = THROTTLED;
1081 	spin_unlock_irq(&priv->lock);
1082 }
1083 
1084 
1085 static void cypress_unthrottle(struct tty_struct *tty)
1086 {
1087 	struct usb_serial_port *port = tty->driver_data;
1088 	struct cypress_private *priv = usb_get_serial_port_data(port);
1089 	int actually_throttled, result;
1090 
1091 	spin_lock_irq(&priv->lock);
1092 	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
1093 	priv->rx_flags = 0;
1094 	spin_unlock_irq(&priv->lock);
1095 
1096 	if (!priv->comm_is_ok)
1097 		return;
1098 
1099 	if (actually_throttled) {
1100 		result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
1101 		if (result) {
1102 			dev_err(&port->dev, "%s - failed submitting read urb, "
1103 					"error %d\n", __func__, result);
1104 			cypress_set_dead(port);
1105 		}
1106 	}
1107 }
1108 
1109 
1110 static void cypress_read_int_callback(struct urb *urb)
1111 {
1112 	struct usb_serial_port *port = urb->context;
1113 	struct cypress_private *priv = usb_get_serial_port_data(port);
1114 	struct device *dev = &urb->dev->dev;
1115 	struct tty_struct *tty;
1116 	unsigned char *data = urb->transfer_buffer;
1117 	unsigned long flags;
1118 	char tty_flag = TTY_NORMAL;
1119 	int havedata = 0;
1120 	int bytes = 0;
1121 	int result;
1122 	int i = 0;
1123 	int status = urb->status;
1124 
1125 	switch (status) {
1126 	case 0: /* success */
1127 		break;
1128 	case -ECONNRESET:
1129 	case -ENOENT:
1130 	case -ESHUTDOWN:
1131 		/* precursor to disconnect so just go away */
1132 		return;
1133 	case -EPIPE:
1134 		/* Can't call usb_clear_halt while in_interrupt */
1135 		/* FALLS THROUGH */
1136 	default:
1137 		/* something ugly is going on... */
1138 		dev_err(dev, "%s - unexpected nonzero read status received: %d\n",
1139 			__func__, status);
1140 		cypress_set_dead(port);
1141 		return;
1142 	}
1143 
1144 	spin_lock_irqsave(&priv->lock, flags);
1145 	if (priv->rx_flags & THROTTLED) {
1146 		dev_dbg(dev, "%s - now throttling\n", __func__);
1147 		priv->rx_flags |= ACTUALLY_THROTTLED;
1148 		spin_unlock_irqrestore(&priv->lock, flags);
1149 		return;
1150 	}
1151 	spin_unlock_irqrestore(&priv->lock, flags);
1152 
1153 	tty = tty_port_tty_get(&port->port);
1154 	if (!tty) {
1155 		dev_dbg(dev, "%s - bad tty pointer - exiting\n", __func__);
1156 		return;
1157 	}
1158 
1159 	spin_lock_irqsave(&priv->lock, flags);
1160 	result = urb->actual_length;
1161 	switch (priv->pkt_fmt) {
1162 	default:
1163 	case packet_format_1:
1164 		/* This is for the CY7C64013... */
1165 		priv->current_status = data[0] & 0xF8;
1166 		bytes = data[1] + 2;
1167 		i = 2;
1168 		if (bytes > 2)
1169 			havedata = 1;
1170 		break;
1171 	case packet_format_2:
1172 		/* This is for the CY7C63743... */
1173 		priv->current_status = data[0] & 0xF8;
1174 		bytes = (data[0] & 0x07) + 1;
1175 		i = 1;
1176 		if (bytes > 1)
1177 			havedata = 1;
1178 		break;
1179 	}
1180 	spin_unlock_irqrestore(&priv->lock, flags);
1181 	if (result < bytes) {
1182 		dev_dbg(dev,
1183 			"%s - wrong packet size - received %d bytes but packet said %d bytes\n",
1184 			__func__, result, bytes);
1185 		goto continue_read;
1186 	}
1187 
1188 	usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
1189 
1190 	spin_lock_irqsave(&priv->lock, flags);
1191 	/* check to see if status has changed */
1192 	if (priv->current_status != priv->prev_status) {
1193 		priv->diff_status |= priv->current_status ^
1194 			priv->prev_status;
1195 		wake_up_interruptible(&priv->delta_msr_wait);
1196 		priv->prev_status = priv->current_status;
1197 	}
1198 	spin_unlock_irqrestore(&priv->lock, flags);
1199 
1200 	/* hangup, as defined in acm.c... this might be a bad place for it
1201 	 * though */
1202 	if (tty && !(tty->termios.c_cflag & CLOCAL) &&
1203 			!(priv->current_status & UART_CD)) {
1204 		dev_dbg(dev, "%s - calling hangup\n", __func__);
1205 		tty_hangup(tty);
1206 		goto continue_read;
1207 	}
1208 
1209 	/* There is one error bit... I'm assuming it is a parity error
1210 	 * indicator as the generic firmware will set this bit to 1 if a
1211 	 * parity error occurs.
1212 	 * I can not find reference to any other error events. */
1213 	spin_lock_irqsave(&priv->lock, flags);
1214 	if (priv->current_status & CYP_ERROR) {
1215 		spin_unlock_irqrestore(&priv->lock, flags);
1216 		tty_flag = TTY_PARITY;
1217 		dev_dbg(dev, "%s - Parity Error detected\n", __func__);
1218 	} else
1219 		spin_unlock_irqrestore(&priv->lock, flags);
1220 
1221 	/* process read if there is data other than line status */
1222 	if (tty && bytes > i) {
1223 		tty_insert_flip_string_fixed_flag(tty, data + i,
1224 				tty_flag, bytes - i);
1225 		tty_flip_buffer_push(tty);
1226 	}
1227 
1228 	spin_lock_irqsave(&priv->lock, flags);
1229 	/* control and status byte(s) are also counted */
1230 	priv->bytes_in += bytes;
1231 	spin_unlock_irqrestore(&priv->lock, flags);
1232 
1233 continue_read:
1234 	tty_kref_put(tty);
1235 
1236 	/* Continue trying to always read */
1237 
1238 	if (priv->comm_is_ok) {
1239 		usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1240 				usb_rcvintpipe(port->serial->dev,
1241 					port->interrupt_in_endpointAddress),
1242 				port->interrupt_in_urb->transfer_buffer,
1243 				port->interrupt_in_urb->transfer_buffer_length,
1244 				cypress_read_int_callback, port,
1245 				priv->read_urb_interval);
1246 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1247 		if (result && result != -EPERM) {
1248 			dev_err(dev, "%s - failed resubmitting read urb, error %d\n",
1249 				__func__, result);
1250 			cypress_set_dead(port);
1251 		}
1252 	}
1253 } /* cypress_read_int_callback */
1254 
1255 
1256 static void cypress_write_int_callback(struct urb *urb)
1257 {
1258 	struct usb_serial_port *port = urb->context;
1259 	struct cypress_private *priv = usb_get_serial_port_data(port);
1260 	struct device *dev = &urb->dev->dev;
1261 	int result;
1262 	int status = urb->status;
1263 
1264 	switch (status) {
1265 	case 0:
1266 		/* success */
1267 		break;
1268 	case -ECONNRESET:
1269 	case -ENOENT:
1270 	case -ESHUTDOWN:
1271 		/* this urb is terminated, clean up */
1272 		dev_dbg(dev, "%s - urb shutting down with status: %d\n",
1273 			__func__, status);
1274 		priv->write_urb_in_use = 0;
1275 		return;
1276 	case -EPIPE: /* no break needed; clear halt and resubmit */
1277 		if (!priv->comm_is_ok)
1278 			break;
1279 		usb_clear_halt(port->serial->dev, 0x02);
1280 		/* error in the urb, so we have to resubmit it */
1281 		dev_dbg(dev, "%s - nonzero write bulk status received: %d\n",
1282 			__func__, status);
1283 		port->interrupt_out_urb->transfer_buffer_length = 1;
1284 		result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
1285 		if (!result)
1286 			return;
1287 		dev_err(dev, "%s - failed resubmitting write urb, error %d\n",
1288 			__func__, result);
1289 		cypress_set_dead(port);
1290 		break;
1291 	default:
1292 		dev_err(dev, "%s - unexpected nonzero write status received: %d\n",
1293 			__func__, status);
1294 		cypress_set_dead(port);
1295 		break;
1296 	}
1297 	priv->write_urb_in_use = 0;
1298 
1299 	/* send any buffered data */
1300 	cypress_send(port);
1301 }
1302 
1303 module_usb_serial_driver(serial_drivers, id_table_combined);
1304 
1305 MODULE_AUTHOR(DRIVER_AUTHOR);
1306 MODULE_DESCRIPTION(DRIVER_DESC);
1307 MODULE_VERSION(DRIVER_VERSION);
1308 MODULE_LICENSE("GPL");
1309 
1310 module_param(stats, bool, S_IRUGO | S_IWUSR);
1311 MODULE_PARM_DESC(stats, "Enable statistics or not");
1312 module_param(interval, int, S_IRUGO | S_IWUSR);
1313 MODULE_PARM_DESC(interval, "Overrides interrupt interval");
1314 module_param(unstable_bauds, bool, S_IRUGO | S_IWUSR);
1315 MODULE_PARM_DESC(unstable_bauds, "Allow unstable baud rates");
1316