xref: /linux/drivers/usb/serial/cypress_m8.c (revision 54a8a2220c936a47840c9a3d74910c5a56fae2ed)
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 driver
15  *
16  * See http://geocities.com/i0xox0i for information on this driver and the
17  * earthmate usb device.
18  *
19  *  Lonnie Mendez <dignome@gmail.com>
20  *  4-29-2005
21  *	Fixed problem where setting or retreiving the serial config would fail with
22  * 	EPIPE.  Removed CRTS toggling so the driver behaves more like other usbserial
23  * 	adapters.  Issued new interval of 1ms instead of the default 10ms.  As a
24  * 	result, transfer speed has been substantially increased.  From avg. 850bps to
25  * 	avg. 3300bps.  initial termios has also been modified.  Cleaned up code and
26  * 	formatting issues so it is more readable.  Replaced the C++ style comments.
27  *
28  *  Lonnie Mendez <dignome@gmail.com>
29  *  12-15-2004
30  *	Incorporated write buffering from pl2303 driver.  Fixed bug with line
31  *	handling so both lines are raised in cypress_open. (was dropping rts)
32  *      Various code cleanups made as well along with other misc bug fixes.
33  *
34  *  Lonnie Mendez <dignome@gmail.com>
35  *  04-10-2004
36  *	Driver modified to support dynamic line settings.  Various improvments
37  *      and features.
38  *
39  *  Neil Whelchel
40  *  10-2003
41  *	Driver first released.
42  *
43  */
44 
45 /* Thanks to Neil Whelchel for writing the first cypress m8 implementation for linux. */
46 /* Thanks to cypress for providing references for the hid reports. */
47 /* Thanks to Jiang Zhang for providing links and for general help. */
48 /* Code originates and was built up from ftdi_sio, belkin, pl2303 and others. */
49 
50 
51 #include <linux/config.h>
52 #include <linux/kernel.h>
53 #include <linux/errno.h>
54 #include <linux/init.h>
55 #include <linux/slab.h>
56 #include <linux/tty.h>
57 #include <linux/tty_driver.h>
58 #include <linux/tty_flip.h>
59 #include <linux/module.h>
60 #include <linux/moduleparam.h>
61 #include <linux/spinlock.h>
62 #include <linux/usb.h>
63 #include <linux/serial.h>
64 #include <linux/delay.h>
65 #include <asm/uaccess.h>
66 
67 #include "usb-serial.h"
68 #include "cypress_m8.h"
69 
70 
71 #ifdef CONFIG_USB_SERIAL_DEBUG
72 	static int debug = 1;
73 #else
74 	static int debug;
75 #endif
76 static int stats;
77 static int interval;
78 
79 /*
80  * Version Information
81  */
82 #define DRIVER_VERSION "v1.09"
83 #define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
84 #define DRIVER_DESC "Cypress USB to Serial Driver"
85 
86 /* write buffer size defines */
87 #define CYPRESS_BUF_SIZE	1024
88 #define CYPRESS_CLOSING_WAIT	(30*HZ)
89 
90 static struct usb_device_id id_table_earthmate [] = {
91 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
92 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
93 	{ }						/* Terminating entry */
94 };
95 
96 static struct usb_device_id id_table_cyphidcomrs232 [] = {
97 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
98 	{ }						/* Terminating entry */
99 };
100 
101 static struct usb_device_id id_table_combined [] = {
102 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
103 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
104 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
105 	{ }						/* Terminating entry */
106 };
107 
108 MODULE_DEVICE_TABLE (usb, id_table_combined);
109 
110 static struct usb_driver cypress_driver = {
111 	.name =		"cypress",
112 	.probe =	usb_serial_probe,
113 	.disconnect =	usb_serial_disconnect,
114 	.id_table =	id_table_combined,
115 };
116 
117 struct cypress_private {
118 	spinlock_t lock;		   /* private lock */
119 	int chiptype;			   /* identifier of device, for quirks/etc */
120 	int bytes_in;			   /* used for statistics */
121 	int bytes_out;			   /* used for statistics */
122 	int cmd_count;			   /* used for statistics */
123 	int cmd_ctrl;			   /* always set this to 1 before issuing a command */
124 	struct cypress_buf *buf;	   /* write buffer */
125 	int write_urb_in_use;		   /* write urb in use indicator */
126 	int termios_initialized;
127 	__u8 line_control;	   	   /* holds dtr / rts value */
128 	__u8 current_status;	   	   /* received from last read - info on dsr,cts,cd,ri,etc */
129 	__u8 current_config;	   	   /* stores the current configuration byte */
130 	__u8 rx_flags;			   /* throttling - used from whiteheat/ftdi_sio */
131 	int baud_rate;			   /* stores current baud rate in integer form */
132 	int cbr_mask;			   /* stores current baud rate in masked form */
133 	int isthrottled;		   /* if throttled, discard reads */
134 	wait_queue_head_t delta_msr_wait;  /* used for TIOCMIWAIT */
135 	char prev_status, diff_status;	   /* used for TIOCMIWAIT */
136 	/* we pass a pointer to this as the arguement sent to cypress_set_termios old_termios */
137 	struct termios tmp_termios; 	   /* stores the old termios settings */
138 };
139 
140 /* write buffer structure */
141 struct cypress_buf {
142 	unsigned int	buf_size;
143 	char		*buf_buf;
144 	char		*buf_get;
145 	char		*buf_put;
146 };
147 
148 /* function prototypes for the Cypress USB to serial device */
149 static int  cypress_earthmate_startup	(struct usb_serial *serial);
150 static int  cypress_hidcom_startup	(struct usb_serial *serial);
151 static void cypress_shutdown		(struct usb_serial *serial);
152 static int  cypress_open		(struct usb_serial_port *port, struct file *filp);
153 static void cypress_close		(struct usb_serial_port *port, struct file *filp);
154 static int  cypress_write		(struct usb_serial_port *port, const unsigned char *buf, int count);
155 static void cypress_send		(struct usb_serial_port *port);
156 static int  cypress_write_room		(struct usb_serial_port *port);
157 static int  cypress_ioctl		(struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg);
158 static void cypress_set_termios		(struct usb_serial_port *port, struct termios * old);
159 static int  cypress_tiocmget		(struct usb_serial_port *port, struct file *file);
160 static int  cypress_tiocmset		(struct usb_serial_port *port, struct file *file, unsigned int set, unsigned int clear);
161 static int  cypress_chars_in_buffer	(struct usb_serial_port *port);
162 static void cypress_throttle		(struct usb_serial_port *port);
163 static void cypress_unthrottle		(struct usb_serial_port *port);
164 static void cypress_read_int_callback	(struct urb *urb, struct pt_regs *regs);
165 static void cypress_write_int_callback	(struct urb *urb, struct pt_regs *regs);
166 /* baud helper functions */
167 static int	 mask_to_rate		(unsigned mask);
168 static unsigned  rate_to_mask		(int rate);
169 /* write buffer functions */
170 static struct cypress_buf *cypress_buf_alloc(unsigned int size);
171 static void 		  cypress_buf_free(struct cypress_buf *cb);
172 static void		  cypress_buf_clear(struct cypress_buf *cb);
173 static unsigned int	  cypress_buf_data_avail(struct cypress_buf *cb);
174 static unsigned int	  cypress_buf_space_avail(struct cypress_buf *cb);
175 static unsigned int	  cypress_buf_put(struct cypress_buf *cb, const char *buf, unsigned int count);
176 static unsigned int	  cypress_buf_get(struct cypress_buf *cb, char *buf, unsigned int count);
177 
178 
179 static struct usb_serial_device_type cypress_earthmate_device = {
180 	.owner =			THIS_MODULE,
181 	.name =				"DeLorme Earthmate USB",
182 	.short_name =			"earthmate",
183 	.id_table =			id_table_earthmate,
184 	.num_interrupt_in = 		1,
185 	.num_interrupt_out =		1,
186 	.num_bulk_in =			NUM_DONT_CARE,
187 	.num_bulk_out =			NUM_DONT_CARE,
188 	.num_ports =			1,
189 	.attach =			cypress_earthmate_startup,
190 	.shutdown =			cypress_shutdown,
191 	.open =				cypress_open,
192 	.close =			cypress_close,
193 	.write =			cypress_write,
194 	.write_room =			cypress_write_room,
195 	.ioctl =			cypress_ioctl,
196 	.set_termios =			cypress_set_termios,
197 	.tiocmget =			cypress_tiocmget,
198 	.tiocmset =			cypress_tiocmset,
199 	.chars_in_buffer =		cypress_chars_in_buffer,
200 	.throttle =		 	cypress_throttle,
201 	.unthrottle =			cypress_unthrottle,
202 	.read_int_callback =		cypress_read_int_callback,
203 	.write_int_callback =		cypress_write_int_callback,
204 };
205 
206 static struct usb_serial_device_type cypress_hidcom_device = {
207 	.owner =			THIS_MODULE,
208 	.name =				"HID->COM RS232 Adapter",
209 	.short_name =			"cyphidcom",
210 	.id_table =			id_table_cyphidcomrs232,
211 	.num_interrupt_in =		1,
212 	.num_interrupt_out =		1,
213 	.num_bulk_in =			NUM_DONT_CARE,
214 	.num_bulk_out =			NUM_DONT_CARE,
215 	.num_ports =			1,
216 	.attach =			cypress_hidcom_startup,
217 	.shutdown =			cypress_shutdown,
218 	.open =				cypress_open,
219 	.close =			cypress_close,
220 	.write =			cypress_write,
221 	.write_room =			cypress_write_room,
222 	.ioctl =			cypress_ioctl,
223 	.set_termios =			cypress_set_termios,
224 	.tiocmget =			cypress_tiocmget,
225 	.tiocmset =			cypress_tiocmset,
226 	.chars_in_buffer =		cypress_chars_in_buffer,
227 	.throttle =			cypress_throttle,
228 	.unthrottle =			cypress_unthrottle,
229 	.read_int_callback =		cypress_read_int_callback,
230 	.write_int_callback =		cypress_write_int_callback,
231 };
232 
233 
234 /*****************************************************************************
235  * Cypress serial helper functions
236  *****************************************************************************/
237 
238 
239 /* This function can either set or retrieve the current serial line settings */
240 static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_mask, int data_bits, int stop_bits,
241 				   int parity_enable, int parity_type, int reset, int cypress_request_type)
242 {
243 	int new_baudrate = 0, retval = 0, tries = 0;
244 	struct cypress_private *priv;
245 	__u8 feature_buffer[8];
246 	unsigned long flags;
247 
248 	dbg("%s", __FUNCTION__);
249 
250 	priv = usb_get_serial_port_data(port);
251 
252 	switch(cypress_request_type) {
253 		case CYPRESS_SET_CONFIG:
254 
255 			/*
256 			 * The general purpose firmware for the Cypress M8 allows for a maximum speed
257  			 * of 57600bps (I have no idea whether DeLorme chose to use the general purpose
258 			 * firmware or not), if you need to modify this speed setting for your own
259 			 * project please add your own chiptype and modify the code likewise.  The
260 			 * Cypress HID->COM device will work successfully up to 115200bps (but the
261 			 * actual throughput is around 3kBps).
262 			 */
263 			if (baud_mask != priv->cbr_mask) {
264 				dbg("%s - baud rate is changing", __FUNCTION__);
265 				if ( priv->chiptype == CT_EARTHMATE ) {
266 					/* 300 and 600 baud rates are supported under the generic firmware,
267 					 * but are not used with NMEA and SiRF protocols */
268 
269 					if ( (baud_mask == B300) || (baud_mask == B600) ) {
270 						err("%s - failed setting baud rate, unsupported speed",
271 						    __FUNCTION__);
272 						new_baudrate = priv->baud_rate;
273 					} else if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
274 						err("%s - failed setting baud rate, unsupported speed",
275 						    __FUNCTION__);
276 						new_baudrate = priv->baud_rate;
277 					}
278 				} else if (priv->chiptype == CT_CYPHIDCOM) {
279 					if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
280 						err("%s - failed setting baud rate, unsupported speed",
281 						    __FUNCTION__);
282 						new_baudrate = priv->baud_rate;
283 					}
284 				} else if (priv->chiptype == CT_GENERIC) {
285 					if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
286 						err("%s - failed setting baud rate, unsupported speed",
287 						    __FUNCTION__);
288 						new_baudrate = priv->baud_rate;
289 					}
290 				} else {
291 					info("%s - please define your chiptype", __FUNCTION__);
292 					new_baudrate = priv->baud_rate;
293 				}
294 			} else {  /* baud rate not changing, keep the old */
295 				new_baudrate = priv->baud_rate;
296 			}
297 			dbg("%s - baud rate is being sent as %d", __FUNCTION__, new_baudrate);
298 
299 			memset(feature_buffer, 0, 8);
300 			/* fill the feature_buffer with new configuration */
301 			*((u_int32_t *)feature_buffer) = new_baudrate;
302 
303 			feature_buffer[4] |= data_bits;   /* assign data bits in 2 bit space ( max 3 ) */
304 			/* 1 bit gap */
305 			feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
306 			feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
307 			feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
308 			/* 1 bit gap */
309 			feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
310 
311 			dbg("%s - device is being sent this feature report:", __FUNCTION__);
312 			dbg("%s - %02X - %02X - %02X - %02X - %02X", __FUNCTION__, feature_buffer[0], feature_buffer[1],
313 		            feature_buffer[2], feature_buffer[3], feature_buffer[4]);
314 
315 			do {
316 			retval = usb_control_msg (port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
317 					  	  HID_REQ_SET_REPORT, USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
318 						  	  0x0300, 0, feature_buffer, 8, 500);
319 
320 				if (tries++ >= 3)
321 					break;
322 
323 				if (retval == EPIPE)
324 					usb_clear_halt(port->serial->dev, 0x00);
325 			} while (retval != 8 && retval != ENODEV);
326 
327 			if (retval != 8)
328 				err("%s - failed sending serial line settings - %d", __FUNCTION__, retval);
329 			else {
330 				spin_lock_irqsave(&priv->lock, flags);
331 				priv->baud_rate = new_baudrate;
332 				priv->cbr_mask = baud_mask;
333 				priv->current_config = feature_buffer[4];
334 				spin_unlock_irqrestore(&priv->lock, flags);
335 			}
336 		break;
337 		case CYPRESS_GET_CONFIG:
338 			dbg("%s - retreiving serial line settings", __FUNCTION__);
339 			/* set initial values in feature buffer */
340 			memset(feature_buffer, 0, 8);
341 
342 			do {
343 			retval = usb_control_msg (port->serial->dev, usb_rcvctrlpipe(port->serial->dev, 0),
344 						  HID_REQ_GET_REPORT, USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
345 							  0x0300, 0, feature_buffer, 8, 500);
346 
347 				if (tries++ >= 3)
348 					break;
349 
350 				if (retval == EPIPE)
351 					usb_clear_halt(port->serial->dev, 0x00);
352 			} while (retval != 5 && retval != ENODEV);
353 
354 			if (retval != 5) {
355 				err("%s - failed to retreive serial line settings - %d", __FUNCTION__, retval);
356 				return retval;
357 			} else {
358 				spin_lock_irqsave(&priv->lock, flags);
359 
360 				/* store the config in one byte, and later use bit masks to check values */
361 				priv->current_config = feature_buffer[4];
362 				priv->baud_rate = *((u_int32_t *)feature_buffer);
363 
364 				if ( (priv->cbr_mask = rate_to_mask(priv->baud_rate)) == 0x40)
365 					dbg("%s - failed setting the baud mask (not defined)", __FUNCTION__);
366 				spin_unlock_irqrestore(&priv->lock, flags);
367 			}
368 	}
369 	spin_lock_irqsave(&priv->lock, flags);
370 	++priv->cmd_count;
371 	spin_unlock_irqrestore(&priv->lock, flags);
372 
373 	return retval;
374 } /* cypress_serial_control */
375 
376 
377 /* given a baud mask, it will return integer baud on success */
378 static int mask_to_rate (unsigned mask)
379 {
380 	int rate;
381 
382 	switch (mask) {
383 		case B0: rate = 0; break;
384 		case B300: rate = 300; break;
385 		case B600: rate = 600; break;
386 		case B1200: rate = 1200; break;
387 		case B2400: rate = 2400; break;
388 		case B4800: rate = 4800; break;
389 		case B9600: rate = 9600; break;
390 		case B19200: rate = 19200; break;
391 		case B38400: rate = 38400; break;
392 		case B57600: rate = 57600; break;
393 		case B115200: rate = 115200; break;
394 		default: rate = -1;
395 	}
396 
397 	return rate;
398 }
399 
400 
401 static unsigned rate_to_mask (int rate)
402 {
403 	unsigned mask;
404 
405 	switch (rate) {
406 		case 0: mask = B0; break;
407 		case 300: mask = B300; break;
408 		case 600: mask = B600; break;
409 		case 1200: mask = B1200; break;
410 		case 2400: mask = B2400; break;
411 		case 4800: mask = B4800; break;
412 		case 9600: mask = B9600; break;
413 		case 19200: mask = B19200; break;
414 		case 38400: mask = B38400; break;
415 		case 57600: mask = B57600; break;
416 		case 115200: mask = B115200; break;
417 		default: mask = 0x40;
418 	}
419 
420 	return mask;
421 }
422 /*****************************************************************************
423  * Cypress serial driver functions
424  *****************************************************************************/
425 
426 
427 static int generic_startup (struct usb_serial *serial)
428 {
429 	struct cypress_private *priv;
430 
431 	dbg("%s - port %d", __FUNCTION__, serial->port[0]->number);
432 
433 	priv = kmalloc(sizeof (struct cypress_private), GFP_KERNEL);
434 	if (!priv)
435 		return -ENOMEM;
436 
437 	memset(priv, 0x00, sizeof (struct cypress_private));
438 	spin_lock_init(&priv->lock);
439 	priv->buf = cypress_buf_alloc(CYPRESS_BUF_SIZE);
440 	if (priv->buf == NULL) {
441 		kfree(priv);
442 		return -ENOMEM;
443 	}
444 	init_waitqueue_head(&priv->delta_msr_wait);
445 
446 	usb_reset_configuration (serial->dev);
447 
448 	interval = 1;
449 	priv->cmd_ctrl = 0;
450 	priv->line_control = 0;
451 	priv->termios_initialized = 0;
452 	priv->rx_flags = 0;
453 	priv->cbr_mask = B300;
454 	usb_set_serial_port_data(serial->port[0], priv);
455 
456 	return 0;
457 }
458 
459 
460 static int cypress_earthmate_startup (struct usb_serial *serial)
461 {
462 	struct cypress_private *priv;
463 
464 	dbg("%s", __FUNCTION__);
465 
466 	if (generic_startup(serial)) {
467 		dbg("%s - Failed setting up port %d", __FUNCTION__,
468 				serial->port[0]->number);
469 		return 1;
470 	}
471 
472 	priv = usb_get_serial_port_data(serial->port[0]);
473 	priv->chiptype = CT_EARTHMATE;
474 
475 	return 0;
476 } /* cypress_earthmate_startup */
477 
478 
479 static int cypress_hidcom_startup (struct usb_serial *serial)
480 {
481 	struct cypress_private *priv;
482 
483 	dbg("%s", __FUNCTION__);
484 
485 	if (generic_startup(serial)) {
486 		dbg("%s - Failed setting up port %d", __FUNCTION__,
487 				serial->port[0]->number);
488 		return 1;
489 	}
490 
491 	priv = usb_get_serial_port_data(serial->port[0]);
492 	priv->chiptype = CT_CYPHIDCOM;
493 
494 	return 0;
495 } /* cypress_hidcom_startup */
496 
497 
498 static void cypress_shutdown (struct usb_serial *serial)
499 {
500 	struct cypress_private *priv;
501 
502 	dbg ("%s - port %d", __FUNCTION__, serial->port[0]->number);
503 
504 	/* all open ports are closed at this point */
505 
506 	priv = usb_get_serial_port_data(serial->port[0]);
507 
508 	if (priv) {
509 		cypress_buf_free(priv->buf);
510 		kfree(priv);
511 		usb_set_serial_port_data(serial->port[0], NULL);
512 	}
513 }
514 
515 
516 static int cypress_open (struct usb_serial_port *port, struct file *filp)
517 {
518 	struct cypress_private *priv = usb_get_serial_port_data(port);
519 	struct usb_serial *serial = port->serial;
520 	unsigned long flags;
521 	int result = 0;
522 
523 	dbg("%s - port %d", __FUNCTION__, port->number);
524 
525 	/* clear halts before open */
526 	usb_clear_halt(serial->dev, 0x81);
527 	usb_clear_halt(serial->dev, 0x02);
528 
529 	spin_lock_irqsave(&priv->lock, flags);
530 	/* reset read/write statistics */
531 	priv->bytes_in = 0;
532 	priv->bytes_out = 0;
533 	priv->cmd_count = 0;
534 	priv->rx_flags = 0;
535 	spin_unlock_irqrestore(&priv->lock, flags);
536 
537 	/* setting to zero could cause data loss */
538 	port->tty->low_latency = 1;
539 
540 	/* raise both lines and set termios */
541 	spin_lock_irqsave(&priv->lock, flags);
542 	priv->line_control = CONTROL_DTR | CONTROL_RTS;
543 	priv->cmd_ctrl = 1;
544 	spin_unlock_irqrestore(&priv->lock, flags);
545 	result = cypress_write(port, NULL, 0);
546 
547 	if (result) {
548 		dev_err(&port->dev, "%s - failed setting the control lines - error %d\n", __FUNCTION__, result);
549 		return result;
550 	} else
551 		dbg("%s - success setting the control lines", __FUNCTION__);
552 
553 	cypress_set_termios(port, &priv->tmp_termios);
554 
555 	/* setup the port and start reading from the device */
556 	if(!port->interrupt_in_urb){
557 		err("%s - interrupt_in_urb is empty!", __FUNCTION__);
558 		return(-1);
559 	}
560 
561 	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
562 		usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
563 		port->interrupt_in_urb->transfer_buffer, port->interrupt_in_urb->transfer_buffer_length,
564 		cypress_read_int_callback, port, interval);
565 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
566 
567 	if (result){
568 		dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
569 	}
570 
571 	return result;
572 } /* cypress_open */
573 
574 
575 static void cypress_close(struct usb_serial_port *port, struct file * filp)
576 {
577 	struct cypress_private *priv = usb_get_serial_port_data(port);
578 	unsigned int c_cflag;
579 	unsigned long flags;
580 	int bps;
581 	long timeout;
582 	wait_queue_t wait;
583 
584 	dbg("%s - port %d", __FUNCTION__, port->number);
585 
586 	/* wait for data to drain from buffer */
587 	spin_lock_irqsave(&priv->lock, flags);
588 	timeout = CYPRESS_CLOSING_WAIT;
589 	init_waitqueue_entry(&wait, current);
590 	add_wait_queue(&port->tty->write_wait, &wait);
591 	for (;;) {
592 		set_current_state(TASK_INTERRUPTIBLE);
593 		if (cypress_buf_data_avail(priv->buf) == 0
594 		|| timeout == 0 || signal_pending(current)
595 		|| !usb_get_intfdata(port->serial->interface))
596 			break;
597 		spin_unlock_irqrestore(&priv->lock, flags);
598 		timeout = schedule_timeout(timeout);
599 		spin_lock_irqsave(&priv->lock, flags);
600 	}
601 	set_current_state(TASK_RUNNING);
602 	remove_wait_queue(&port->tty->write_wait, &wait);
603 	/* clear out any remaining data in the buffer */
604 	cypress_buf_clear(priv->buf);
605 	spin_unlock_irqrestore(&priv->lock, flags);
606 
607 	/* wait for characters to drain from device */
608 	bps = tty_get_baud_rate(port->tty);
609 	if (bps > 1200)
610 		timeout = max((HZ*2560)/bps,HZ/10);
611 	else
612 		timeout = 2*HZ;
613 	schedule_timeout_interruptible(timeout);
614 
615 	dbg("%s - stopping urbs", __FUNCTION__);
616 	usb_kill_urb (port->interrupt_in_urb);
617 	usb_kill_urb (port->interrupt_out_urb);
618 
619 	if (port->tty) {
620 		c_cflag = port->tty->termios->c_cflag;
621 		if (c_cflag & HUPCL) {
622 			/* drop dtr and rts */
623 			priv = usb_get_serial_port_data(port);
624 			spin_lock_irqsave(&priv->lock, flags);
625 			priv->line_control = 0;
626 			priv->cmd_ctrl = 1;
627 			spin_unlock_irqrestore(&priv->lock, flags);
628 			cypress_write(port, NULL, 0);
629 		}
630 	}
631 
632 	if (stats)
633 		dev_info (&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
634 		          priv->bytes_in, priv->bytes_out, priv->cmd_count);
635 } /* cypress_close */
636 
637 
638 static int cypress_write(struct usb_serial_port *port, const unsigned char *buf, int count)
639 {
640 	struct cypress_private *priv = usb_get_serial_port_data(port);
641 	unsigned long flags;
642 
643 	dbg("%s - port %d, %d bytes", __FUNCTION__, port->number, count);
644 
645 	/* line control commands, which need to be executed immediately,
646 	   are not put into the buffer for obvious reasons.
647 	 */
648 	if (priv->cmd_ctrl) {
649 		count = 0;
650 		goto finish;
651 	}
652 
653 	if (!count)
654 		return count;
655 
656 	spin_lock_irqsave(&priv->lock, flags);
657 	count = cypress_buf_put(priv->buf, buf, count);
658 	spin_unlock_irqrestore(&priv->lock, flags);
659 
660 finish:
661 	cypress_send(port);
662 
663 	return count;
664 } /* cypress_write */
665 
666 
667 static void cypress_send(struct usb_serial_port *port)
668 {
669 	int count = 0, result, offset, actual_size;
670 	struct cypress_private *priv = usb_get_serial_port_data(port);
671 	unsigned long flags;
672 
673 	dbg("%s - port %d", __FUNCTION__, port->number);
674 	dbg("%s - interrupt out size is %d", __FUNCTION__, port->interrupt_out_size);
675 
676 	spin_lock_irqsave(&priv->lock, flags);
677 	if (priv->write_urb_in_use) {
678 		dbg("%s - can't write, urb in use", __FUNCTION__);
679 		spin_unlock_irqrestore(&priv->lock, flags);
680 		return;
681 	}
682 	spin_unlock_irqrestore(&priv->lock, flags);
683 
684 	/* clear buffer */
685 	memset(port->interrupt_out_urb->transfer_buffer, 0, port->interrupt_out_size);
686 
687 	spin_lock_irqsave(&priv->lock, flags);
688 	switch (port->interrupt_out_size) {
689 		case 32:
690 			/* this is for the CY7C64013... */
691 			offset = 2;
692 			port->interrupt_out_buffer[0] = priv->line_control;
693 			break;
694 		case 8:
695 			/* this is for the CY7C63743... */
696 			offset = 1;
697 			port->interrupt_out_buffer[0] = priv->line_control;
698 			break;
699 		default:
700 			dbg("%s - wrong packet size", __FUNCTION__);
701 			spin_unlock_irqrestore(&priv->lock, flags);
702 			return;
703 	}
704 
705 	if (priv->line_control & CONTROL_RESET)
706 		priv->line_control &= ~CONTROL_RESET;
707 
708 	if (priv->cmd_ctrl) {
709 		priv->cmd_count++;
710 		dbg("%s - line control command being issued", __FUNCTION__);
711 		spin_unlock_irqrestore(&priv->lock, flags);
712 		goto send;
713 	} else
714 		spin_unlock_irqrestore(&priv->lock, flags);
715 
716 	count = cypress_buf_get(priv->buf, &port->interrupt_out_buffer[offset],
717 				port->interrupt_out_size-offset);
718 
719 	if (count == 0) {
720 		return;
721 	}
722 
723 	switch (port->interrupt_out_size) {
724 		case 32:
725 			port->interrupt_out_buffer[1] = count;
726 			break;
727 		case 8:
728 			port->interrupt_out_buffer[0] |= count;
729 	}
730 
731 	dbg("%s - count is %d", __FUNCTION__, count);
732 
733 send:
734 	spin_lock_irqsave(&priv->lock, flags);
735 	priv->write_urb_in_use = 1;
736 	spin_unlock_irqrestore(&priv->lock, flags);
737 
738 	if (priv->cmd_ctrl)
739 		actual_size = 1;
740 	else
741 		actual_size = count + (port->interrupt_out_size == 32 ? 2 : 1);
742 
743 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, port->interrupt_out_size,
744 			      port->interrupt_out_urb->transfer_buffer);
745 
746 	port->interrupt_out_urb->transfer_buffer_length = actual_size;
747 	port->interrupt_out_urb->dev = port->serial->dev;
748 	port->interrupt_out_urb->interval = interval;
749 	result = usb_submit_urb (port->interrupt_out_urb, GFP_ATOMIC);
750 	if (result) {
751 		dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__,
752 			result);
753 		priv->write_urb_in_use = 0;
754 	}
755 
756 	spin_lock_irqsave(&priv->lock, flags);
757 	if (priv->cmd_ctrl) {
758 		priv->cmd_ctrl = 0;
759 	}
760 	priv->bytes_out += count; /* do not count the line control and size bytes */
761 	spin_unlock_irqrestore(&priv->lock, flags);
762 
763 	schedule_work(&port->work);
764 } /* cypress_send */
765 
766 
767 /* returns how much space is available in the soft buffer */
768 static int cypress_write_room(struct usb_serial_port *port)
769 {
770 	struct cypress_private *priv = usb_get_serial_port_data(port);
771 	int room = 0;
772 	unsigned long flags;
773 
774 	dbg("%s - port %d", __FUNCTION__, port->number);
775 
776 	spin_lock_irqsave(&priv->lock, flags);
777 	room = cypress_buf_space_avail(priv->buf);
778 	spin_unlock_irqrestore(&priv->lock, flags);
779 
780 	dbg("%s - returns %d", __FUNCTION__, room);
781 	return room;
782 }
783 
784 
785 static int cypress_tiocmget (struct usb_serial_port *port, struct file *file)
786 {
787 	struct cypress_private *priv = usb_get_serial_port_data(port);
788 	__u8 status, control;
789 	unsigned int result = 0;
790 	unsigned long flags;
791 
792 	dbg("%s - port %d", __FUNCTION__, port->number);
793 
794 	spin_lock_irqsave(&priv->lock, flags);
795 	control = priv->line_control;
796 	status = priv->current_status;
797 	spin_unlock_irqrestore(&priv->lock, flags);
798 
799 	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
800 		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
801 		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
802 		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
803 		| ((status & UART_RI)         ? TIOCM_RI  : 0)
804 		| ((status & UART_CD)         ? TIOCM_CD  : 0);
805 
806 	dbg("%s - result = %x", __FUNCTION__, result);
807 
808 	return result;
809 }
810 
811 
812 static int cypress_tiocmset (struct usb_serial_port *port, struct file *file,
813 			       unsigned int set, unsigned int clear)
814 {
815 	struct cypress_private *priv = usb_get_serial_port_data(port);
816 	unsigned long flags;
817 
818 	dbg("%s - port %d", __FUNCTION__, port->number);
819 
820 	spin_lock_irqsave(&priv->lock, flags);
821 	if (set & TIOCM_RTS)
822 		priv->line_control |= CONTROL_RTS;
823 	if (set & TIOCM_DTR)
824 		priv->line_control |= CONTROL_DTR;
825 	if (clear & TIOCM_RTS)
826 		priv->line_control &= ~CONTROL_RTS;
827 	if (clear & TIOCM_DTR)
828 		priv->line_control &= ~CONTROL_DTR;
829 	spin_unlock_irqrestore(&priv->lock, flags);
830 
831 	priv->cmd_ctrl = 1;
832 	return cypress_write(port, NULL, 0);
833 }
834 
835 
836 static int cypress_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
837 {
838 	struct cypress_private *priv = usb_get_serial_port_data(port);
839 
840 	dbg("%s - port %d, cmd 0x%.4x", __FUNCTION__, port->number, cmd);
841 
842 	switch (cmd) {
843 		case TIOCGSERIAL:
844 			if (copy_to_user((void __user *)arg, port->tty->termios, sizeof(struct termios))) {
845 				return -EFAULT;
846 			}
847 			return (0);
848 			break;
849 		case TIOCSSERIAL:
850 			if (copy_from_user(port->tty->termios, (void __user *)arg, sizeof(struct termios))) {
851 				return -EFAULT;
852 			}
853 			/* here we need to call cypress_set_termios to invoke the new settings */
854 			cypress_set_termios(port, &priv->tmp_termios);
855 			return (0);
856 			break;
857 		/* these are called when setting baud rate from gpsd */
858 		case TCGETS:
859 			if (copy_to_user((void __user *)arg, port->tty->termios, sizeof(struct termios))) {
860 				return -EFAULT;
861 			}
862 			return (0);
863 			break;
864 		case TCSETS:
865 			if (copy_from_user(port->tty->termios, (void __user *)arg, sizeof(struct termios))) {
866 				return -EFAULT;
867 			}
868 			/* here we need to call cypress_set_termios to invoke the new settings */
869 			cypress_set_termios(port, &priv->tmp_termios);
870 			return (0);
871 			break;
872 		/* This code comes from drivers/char/serial.c and ftdi_sio.c */
873 		case TIOCMIWAIT:
874 			while (priv != NULL) {
875 				interruptible_sleep_on(&priv->delta_msr_wait);
876 				/* see if a signal did it */
877 				if (signal_pending(current))
878 					return -ERESTARTSYS;
879 				else {
880 					char diff = priv->diff_status;
881 
882 					if (diff == 0) {
883 						return -EIO; /* no change => error */
884 					}
885 
886 					/* consume all events */
887 					priv->diff_status = 0;
888 
889 					/* return 0 if caller wanted to know about these bits */
890 					if ( ((arg & TIOCM_RNG) && (diff & UART_RI)) ||
891 					     ((arg & TIOCM_DSR) && (diff & UART_DSR)) ||
892 					     ((arg & TIOCM_CD) && (diff & UART_CD)) ||
893 					     ((arg & TIOCM_CTS) && (diff & UART_CTS)) ) {
894 						return 0;
895 					}
896 					/* otherwise caller can't care less about what happened,
897 					 * and so we continue to wait for more events.
898 					 */
899 				}
900 			}
901 			return 0;
902 			break;
903 		default:
904 			break;
905 	}
906 
907 	dbg("%s - arg not supported - it was 0x%04x - check include/asm/ioctls.h", __FUNCTION__, cmd);
908 
909 	return -ENOIOCTLCMD;
910 } /* cypress_ioctl */
911 
912 
913 static void cypress_set_termios (struct usb_serial_port *port,
914 		struct termios *old_termios)
915 {
916 	struct cypress_private *priv = usb_get_serial_port_data(port);
917 	struct tty_struct *tty;
918 	int data_bits, stop_bits, parity_type, parity_enable;
919 	unsigned cflag, iflag, baud_mask;
920 	unsigned long flags;
921 	__u8 oldlines;
922 	int linechange = 0;
923 
924 	dbg("%s - port %d", __FUNCTION__, port->number);
925 
926 	tty = port->tty;
927 	if ((!tty) || (!tty->termios)) {
928 		dbg("%s - no tty structures", __FUNCTION__);
929 		return;
930 	}
931 
932 	spin_lock_irqsave(&priv->lock, flags);
933 	if (!priv->termios_initialized) {
934 		if (priv->chiptype == CT_EARTHMATE) {
935 			*(tty->termios) = tty_std_termios;
936 			tty->termios->c_cflag = B4800 | CS8 | CREAD | HUPCL |
937 				CLOCAL;
938 		} else if (priv->chiptype == CT_CYPHIDCOM) {
939 			*(tty->termios) = tty_std_termios;
940 			tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL |
941 				CLOCAL;
942 		}
943 		priv->termios_initialized = 1;
944 	}
945 	spin_unlock_irqrestore(&priv->lock, flags);
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 		if ((cflag != old_termios->c_cflag) ||
953 			(RELEVANT_IFLAG(iflag) !=
954 			 RELEVANT_IFLAG(old_termios->c_iflag))) {
955 			dbg("%s - attempting to set new termios settings",
956 					__FUNCTION__);
957 			/* should make a copy of this in case something goes
958 			 * wrong in the function, we can restore it */
959 			spin_lock_irqsave(&priv->lock, flags);
960 			priv->tmp_termios = *(tty->termios);
961 			spin_unlock_irqrestore(&priv->lock, flags);
962 		} else {
963 			dbg("%s - nothing to do, exiting", __FUNCTION__);
964 			return;
965 		}
966 	} else
967 		return;
968 
969 	/* set number of data bits, parity, stop bits */
970 	/* when parity is disabled the parity type bit is ignored */
971 
972 	/* 1 means 2 stop bits, 0 means 1 stop bit */
973 	stop_bits = cflag & CSTOPB ? 1 : 0;
974 
975 	if (cflag & PARENB) {
976 		parity_enable = 1;
977 		/* 1 means odd parity, 0 means even parity */
978 		parity_type = cflag & PARODD ? 1 : 0;
979 	} else
980 		parity_enable = parity_type = 0;
981 
982 	if (cflag & CSIZE) {
983 		switch (cflag & CSIZE) {
984 			case CS5:
985 				data_bits = 0;
986 				break;
987 			case CS6:
988 				data_bits = 1;
989 				break;
990 			case CS7:
991 				data_bits = 2;
992 				break;
993 			case CS8:
994 				data_bits = 3;
995 				break;
996 			default:
997 				err("%s - CSIZE was set, but not CS5-CS8",
998 						__FUNCTION__);
999 				data_bits = 3;
1000 		}
1001 	} else
1002 		data_bits = 3;
1003 
1004 	spin_lock_irqsave(&priv->lock, flags);
1005 	oldlines = priv->line_control;
1006 	if ((cflag & CBAUD) == B0) {
1007 		/* drop dtr and rts */
1008 		dbg("%s - dropping the lines, baud rate 0bps", __FUNCTION__);
1009 		baud_mask = B0;
1010 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
1011 	} else {
1012 		baud_mask = (cflag & CBAUD);
1013 		switch(baud_mask) {
1014 			case B300:
1015 				dbg("%s - setting baud 300bps", __FUNCTION__);
1016 				break;
1017 			case B600:
1018 				dbg("%s - setting baud 600bps", __FUNCTION__);
1019 				break;
1020 			case B1200:
1021 				dbg("%s - setting baud 1200bps", __FUNCTION__);
1022 				break;
1023 			case B2400:
1024 				dbg("%s - setting baud 2400bps", __FUNCTION__);
1025 				break;
1026 			case B4800:
1027 				dbg("%s - setting baud 4800bps", __FUNCTION__);
1028 				break;
1029 			case B9600:
1030 				dbg("%s - setting baud 9600bps", __FUNCTION__);
1031 				break;
1032 			case B19200:
1033 				dbg("%s - setting baud 19200bps", __FUNCTION__);
1034 				break;
1035 			case B38400:
1036 				dbg("%s - setting baud 38400bps", __FUNCTION__);
1037 				break;
1038 			case B57600:
1039 				dbg("%s - setting baud 57600bps", __FUNCTION__);
1040 				break;
1041 			case B115200:
1042 				dbg("%s - setting baud 115200bps", __FUNCTION__);
1043 				break;
1044 			default:
1045 				dbg("%s - unknown masked baud rate", __FUNCTION__);
1046 		}
1047 		priv->line_control = (CONTROL_DTR | CONTROL_RTS);
1048 	}
1049 	spin_unlock_irqrestore(&priv->lock, flags);
1050 
1051 	dbg("%s - sending %d stop_bits, %d parity_enable, %d parity_type, "
1052 			"%d data_bits (+5)", __FUNCTION__, stop_bits,
1053 			parity_enable, parity_type, data_bits);
1054 
1055 	cypress_serial_control(port, baud_mask, data_bits, stop_bits,
1056 			parity_enable, parity_type, 0, CYPRESS_SET_CONFIG);
1057 
1058 	/* we perform a CYPRESS_GET_CONFIG so that the current settings are
1059 	 * filled into the private structure this should confirm that all is
1060 	 * working if it returns what we just set */
1061 	cypress_serial_control(port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
1062 
1063 	/* Here we can define custom tty settings for devices; the main tty
1064 	 * termios flag base comes from empeg.c */
1065 
1066 	spin_lock_irqsave(&priv->lock, flags);
1067 	if ( (priv->chiptype == CT_EARTHMATE) && (priv->baud_rate == 4800) ) {
1068 		dbg("Using custom termios settings for a baud rate of "
1069 				"4800bps.");
1070 		/* define custom termios settings for NMEA protocol */
1071 
1072 		tty->termios->c_iflag /* input modes - */
1073 			&= ~(IGNBRK  /* disable ignore break */
1074 			| BRKINT     /* disable break causes interrupt */
1075 			| PARMRK     /* disable mark parity errors */
1076 			| ISTRIP     /* disable clear high bit of input char */
1077 			| INLCR      /* disable translate NL to CR */
1078 			| IGNCR      /* disable ignore CR */
1079 			| ICRNL      /* disable translate CR to NL */
1080 			| IXON);     /* disable enable XON/XOFF flow control */
1081 
1082 		tty->termios->c_oflag /* output modes */
1083 			&= ~OPOST;    /* disable postprocess output char */
1084 
1085 		tty->termios->c_lflag /* line discipline modes */
1086 			&= ~(ECHO     /* disable echo input characters */
1087 			| ECHONL      /* disable echo new line */
1088 			| ICANON      /* disable erase, kill, werase, and rprnt
1089 					 special characters */
1090 			| ISIG        /* disable interrupt, quit, and suspend
1091 					 special characters */
1092 			| IEXTEN);    /* disable non-POSIX special characters */
1093 	} /* CT_CYPHIDCOM: Application should handle this for device */
1094 
1095 	linechange = (priv->line_control != oldlines);
1096 	spin_unlock_irqrestore(&priv->lock, flags);
1097 
1098 	/* if necessary, set lines */
1099 	if (linechange) {
1100 		priv->cmd_ctrl = 1;
1101 		cypress_write(port, NULL, 0);
1102 	}
1103 } /* cypress_set_termios */
1104 
1105 
1106 /* returns amount of data still left in soft buffer */
1107 static int cypress_chars_in_buffer(struct usb_serial_port *port)
1108 {
1109 	struct cypress_private *priv = usb_get_serial_port_data(port);
1110 	int chars = 0;
1111 	unsigned long flags;
1112 
1113 	dbg("%s - port %d", __FUNCTION__, port->number);
1114 
1115 	spin_lock_irqsave(&priv->lock, flags);
1116 	chars = cypress_buf_data_avail(priv->buf);
1117 	spin_unlock_irqrestore(&priv->lock, flags);
1118 
1119 	dbg("%s - returns %d", __FUNCTION__, chars);
1120 	return chars;
1121 }
1122 
1123 
1124 static void cypress_throttle (struct usb_serial_port *port)
1125 {
1126 	struct cypress_private *priv = usb_get_serial_port_data(port);
1127 	unsigned long flags;
1128 
1129 	dbg("%s - port %d", __FUNCTION__, port->number);
1130 
1131 	spin_lock_irqsave(&priv->lock, flags);
1132 	priv->rx_flags = THROTTLED;
1133 	spin_unlock_irqrestore(&priv->lock, flags);
1134 }
1135 
1136 
1137 static void cypress_unthrottle (struct usb_serial_port *port)
1138 {
1139 	struct cypress_private *priv = usb_get_serial_port_data(port);
1140 	int actually_throttled, result;
1141 	unsigned long flags;
1142 
1143 	dbg("%s - port %d", __FUNCTION__, port->number);
1144 
1145 	spin_lock_irqsave(&priv->lock, flags);
1146 	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
1147 	priv->rx_flags = 0;
1148 	spin_unlock_irqrestore(&priv->lock, flags);
1149 
1150 	if (actually_throttled) {
1151 		port->interrupt_in_urb->dev = port->serial->dev;
1152 
1153 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1154 		if (result)
1155 			dev_err(&port->dev, "%s - failed submitting read urb, "
1156 					"error %d\n", __FUNCTION__, result);
1157 	}
1158 }
1159 
1160 
1161 static void cypress_read_int_callback(struct urb *urb, struct pt_regs *regs)
1162 {
1163 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
1164 	struct cypress_private *priv = usb_get_serial_port_data(port);
1165 	struct tty_struct *tty;
1166 	unsigned char *data = urb->transfer_buffer;
1167 	unsigned long flags;
1168 	char tty_flag = TTY_NORMAL;
1169 	int havedata = 0;
1170 	int bytes = 0;
1171 	int result;
1172 	int i = 0;
1173 
1174 	dbg("%s - port %d", __FUNCTION__, port->number);
1175 
1176 	if (urb->status) {
1177 		dbg("%s - nonzero read status received: %d", __FUNCTION__,
1178 				urb->status);
1179 		return;
1180 	}
1181 
1182 	spin_lock_irqsave(&priv->lock, flags);
1183 	if (priv->rx_flags & THROTTLED) {
1184 		dbg("%s - now throttling", __FUNCTION__);
1185 		priv->rx_flags |= ACTUALLY_THROTTLED;
1186 		spin_unlock_irqrestore(&priv->lock, flags);
1187 		return;
1188 	}
1189 	spin_unlock_irqrestore(&priv->lock, flags);
1190 
1191 	tty = port->tty;
1192 	if (!tty) {
1193 		dbg("%s - bad tty pointer - exiting", __FUNCTION__);
1194 		return;
1195 	}
1196 
1197 	spin_lock_irqsave(&priv->lock, flags);
1198 	switch(urb->actual_length) {
1199 		case 32:
1200 			/* This is for the CY7C64013... */
1201 			priv->current_status = data[0] & 0xF8;
1202 			bytes = data[1] + 2;
1203 			i = 2;
1204 			if (bytes > 2)
1205 				havedata = 1;
1206 			break;
1207 		case 8:
1208 			/* This is for the CY7C63743... */
1209 			priv->current_status = data[0] & 0xF8;
1210 			bytes = (data[0] & 0x07) + 1;
1211 			i = 1;
1212 			if (bytes > 1)
1213 				havedata = 1;
1214 			break;
1215 		default:
1216 			dbg("%s - wrong packet size - received %d bytes",
1217 					__FUNCTION__, urb->actual_length);
1218 			spin_unlock_irqrestore(&priv->lock, flags);
1219 			goto continue_read;
1220 	}
1221 	spin_unlock_irqrestore(&priv->lock, flags);
1222 
1223 	usb_serial_debug_data (debug, &port->dev, __FUNCTION__,
1224 			urb->actual_length, data);
1225 
1226 	spin_lock_irqsave(&priv->lock, flags);
1227 	/* check to see if status has changed */
1228 	if (priv != NULL) {
1229 		if (priv->current_status != priv->prev_status) {
1230 			priv->diff_status |= priv->current_status ^
1231 				priv->prev_status;
1232 			wake_up_interruptible(&priv->delta_msr_wait);
1233 			priv->prev_status = priv->current_status;
1234 		}
1235 	}
1236 	spin_unlock_irqrestore(&priv->lock, flags);
1237 
1238 	/* hangup, as defined in acm.c... this might be a bad place for it
1239 	 * though */
1240 	if (tty && !(tty->termios->c_cflag & CLOCAL) &&
1241 			!(priv->current_status & UART_CD)) {
1242 		dbg("%s - calling hangup", __FUNCTION__);
1243 		tty_hangup(tty);
1244 		goto continue_read;
1245 	}
1246 
1247 	/* There is one error bit... I'm assuming it is a parity error
1248 	 * indicator as the generic firmware will set this bit to 1 if a
1249 	 * parity error occurs.
1250 	 * I can not find reference to any other error events. */
1251 	spin_lock_irqsave(&priv->lock, flags);
1252 	if (priv->current_status & CYP_ERROR) {
1253 		spin_unlock_irqrestore(&priv->lock, flags);
1254 		tty_flag = TTY_PARITY;
1255 		dbg("%s - Parity Error detected", __FUNCTION__);
1256 	} else
1257 		spin_unlock_irqrestore(&priv->lock, flags);
1258 
1259 	/* process read if there is data other than line status */
1260 	if (tty && (bytes > i)) {
1261 		for (; i < bytes ; ++i) {
1262 			dbg("pushing byte number %d - %d - %c", i, data[i],
1263 					data[i]);
1264 			if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
1265 				tty_flip_buffer_push(tty);
1266 			}
1267 			tty_insert_flip_char(tty, data[i], tty_flag);
1268 		}
1269 		tty_flip_buffer_push(port->tty);
1270 	}
1271 
1272 	spin_lock_irqsave(&priv->lock, flags);
1273 	/* control and status byte(s) are also counted */
1274 	priv->bytes_in += bytes;
1275 	spin_unlock_irqrestore(&priv->lock, flags);
1276 
1277 continue_read:
1278 
1279 	/* Continue trying to always read... unless the port has closed. */
1280 
1281 	if (port->open_count > 0) {
1282 		usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1283 				usb_rcvintpipe(port->serial->dev,
1284 					port->interrupt_in_endpointAddress),
1285 				port->interrupt_in_urb->transfer_buffer,
1286 				port->interrupt_in_urb->transfer_buffer_length,
1287 				cypress_read_int_callback, port, interval);
1288 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1289 		if (result)
1290 			dev_err(&urb->dev->dev, "%s - failed resubmitting "
1291 					"read urb, error %d\n", __FUNCTION__,
1292 					result);
1293 	}
1294 
1295 	return;
1296 } /* cypress_read_int_callback */
1297 
1298 
1299 static void cypress_write_int_callback(struct urb *urb, struct pt_regs *regs)
1300 {
1301 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
1302 	struct cypress_private *priv = usb_get_serial_port_data(port);
1303 	int result;
1304 
1305 	dbg("%s - port %d", __FUNCTION__, port->number);
1306 
1307 	switch (urb->status) {
1308 		case 0:
1309 			/* success */
1310 			break;
1311 		case -ECONNRESET:
1312 		case -ENOENT:
1313 		case -ESHUTDOWN:
1314 			/* this urb is terminated, clean up */
1315 			dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
1316 			priv->write_urb_in_use = 0;
1317 			return;
1318 		case -EPIPE: /* no break needed */
1319 			usb_clear_halt(port->serial->dev, 0x02);
1320 		default:
1321 			/* error in the urb, so we have to resubmit it */
1322 			dbg("%s - Overflow in write", __FUNCTION__);
1323 			dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
1324 			port->interrupt_out_urb->transfer_buffer_length = 1;
1325 			port->interrupt_out_urb->dev = port->serial->dev;
1326 			result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
1327 			if (result)
1328 				dev_err(&urb->dev->dev, "%s - failed resubmitting write urb, error %d\n",
1329 					__FUNCTION__, result);
1330 			else
1331 				return;
1332 	}
1333 
1334 	priv->write_urb_in_use = 0;
1335 
1336 	/* send any buffered data */
1337 	cypress_send(port);
1338 }
1339 
1340 
1341 /*****************************************************************************
1342  * Write buffer functions - buffering code from pl2303 used
1343  *****************************************************************************/
1344 
1345 /*
1346  * cypress_buf_alloc
1347  *
1348  * Allocate a circular buffer and all associated memory.
1349  */
1350 
1351 static struct cypress_buf *cypress_buf_alloc(unsigned int size)
1352 {
1353 
1354 	struct cypress_buf *cb;
1355 
1356 
1357 	if (size == 0)
1358 		return NULL;
1359 
1360 	cb = (struct cypress_buf *)kmalloc(sizeof(struct cypress_buf), GFP_KERNEL);
1361 	if (cb == NULL)
1362 		return NULL;
1363 
1364 	cb->buf_buf = kmalloc(size, GFP_KERNEL);
1365 	if (cb->buf_buf == NULL) {
1366 		kfree(cb);
1367 		return NULL;
1368 	}
1369 
1370 	cb->buf_size = size;
1371 	cb->buf_get = cb->buf_put = cb->buf_buf;
1372 
1373 	return cb;
1374 
1375 }
1376 
1377 
1378 /*
1379  * cypress_buf_free
1380  *
1381  * Free the buffer and all associated memory.
1382  */
1383 
1384 static void cypress_buf_free(struct cypress_buf *cb)
1385 {
1386 	if (cb) {
1387 		kfree(cb->buf_buf);
1388 		kfree(cb);
1389 	}
1390 }
1391 
1392 
1393 /*
1394  * cypress_buf_clear
1395  *
1396  * Clear out all data in the circular buffer.
1397  */
1398 
1399 static void cypress_buf_clear(struct cypress_buf *cb)
1400 {
1401 	if (cb != NULL)
1402 		cb->buf_get = cb->buf_put;
1403 		/* equivalent to a get of all data available */
1404 }
1405 
1406 
1407 /*
1408  * cypress_buf_data_avail
1409  *
1410  * Return the number of bytes of data available in the circular
1411  * buffer.
1412  */
1413 
1414 static unsigned int cypress_buf_data_avail(struct cypress_buf *cb)
1415 {
1416 	if (cb != NULL)
1417 		return ((cb->buf_size + cb->buf_put - cb->buf_get) % cb->buf_size);
1418 	else
1419 		return 0;
1420 }
1421 
1422 
1423 /*
1424  * cypress_buf_space_avail
1425  *
1426  * Return the number of bytes of space available in the circular
1427  * buffer.
1428  */
1429 
1430 static unsigned int cypress_buf_space_avail(struct cypress_buf *cb)
1431 {
1432 	if (cb != NULL)
1433 		return ((cb->buf_size + cb->buf_get - cb->buf_put - 1) % cb->buf_size);
1434 	else
1435 		return 0;
1436 }
1437 
1438 
1439 /*
1440  * cypress_buf_put
1441  *
1442  * Copy data data from a user buffer and put it into the circular buffer.
1443  * Restrict to the amount of space available.
1444  *
1445  * Return the number of bytes copied.
1446  */
1447 
1448 static unsigned int cypress_buf_put(struct cypress_buf *cb, const char *buf,
1449 	unsigned int count)
1450 {
1451 
1452 	unsigned int len;
1453 
1454 
1455 	if (cb == NULL)
1456 		return 0;
1457 
1458 	len  = cypress_buf_space_avail(cb);
1459 	if (count > len)
1460 		count = len;
1461 
1462 	if (count == 0)
1463 		return 0;
1464 
1465 	len = cb->buf_buf + cb->buf_size - cb->buf_put;
1466 	if (count > len) {
1467 		memcpy(cb->buf_put, buf, len);
1468 		memcpy(cb->buf_buf, buf+len, count - len);
1469 		cb->buf_put = cb->buf_buf + count - len;
1470 	} else {
1471 		memcpy(cb->buf_put, buf, count);
1472 		if (count < len)
1473 			cb->buf_put += count;
1474 		else /* count == len */
1475 			cb->buf_put = cb->buf_buf;
1476 	}
1477 
1478 	return count;
1479 
1480 }
1481 
1482 
1483 /*
1484  * cypress_buf_get
1485  *
1486  * Get data from the circular buffer and copy to the given buffer.
1487  * Restrict to the amount of data available.
1488  *
1489  * Return the number of bytes copied.
1490  */
1491 
1492 static unsigned int cypress_buf_get(struct cypress_buf *cb, char *buf,
1493 	unsigned int count)
1494 {
1495 
1496 	unsigned int len;
1497 
1498 
1499 	if (cb == NULL)
1500 		return 0;
1501 
1502 	len = cypress_buf_data_avail(cb);
1503 	if (count > len)
1504 		count = len;
1505 
1506 	if (count == 0)
1507 		return 0;
1508 
1509 	len = cb->buf_buf + cb->buf_size - cb->buf_get;
1510 	if (count > len) {
1511 		memcpy(buf, cb->buf_get, len);
1512 		memcpy(buf+len, cb->buf_buf, count - len);
1513 		cb->buf_get = cb->buf_buf + count - len;
1514 	} else {
1515 		memcpy(buf, cb->buf_get, count);
1516 		if (count < len)
1517 			cb->buf_get += count;
1518 		else /* count == len */
1519 			cb->buf_get = cb->buf_buf;
1520 	}
1521 
1522 	return count;
1523 
1524 }
1525 
1526 /*****************************************************************************
1527  * Module functions
1528  *****************************************************************************/
1529 
1530 static int __init cypress_init(void)
1531 {
1532 	int retval;
1533 
1534 	dbg("%s", __FUNCTION__);
1535 
1536 	retval = usb_serial_register(&cypress_earthmate_device);
1537 	if (retval)
1538 		goto failed_em_register;
1539 	retval = usb_serial_register(&cypress_hidcom_device);
1540 	if (retval)
1541 		goto failed_hidcom_register;
1542 	retval = usb_register(&cypress_driver);
1543 	if (retval)
1544 		goto failed_usb_register;
1545 
1546 	info(DRIVER_DESC " " DRIVER_VERSION);
1547 	return 0;
1548 failed_usb_register:
1549 	usb_deregister(&cypress_driver);
1550 failed_hidcom_register:
1551 	usb_serial_deregister(&cypress_hidcom_device);
1552 failed_em_register:
1553 	usb_serial_deregister(&cypress_earthmate_device);
1554 
1555 	return retval;
1556 }
1557 
1558 
1559 static void __exit cypress_exit (void)
1560 {
1561 	dbg("%s", __FUNCTION__);
1562 
1563 	usb_deregister (&cypress_driver);
1564 	usb_serial_deregister (&cypress_earthmate_device);
1565 	usb_serial_deregister (&cypress_hidcom_device);
1566 }
1567 
1568 
1569 module_init(cypress_init);
1570 module_exit(cypress_exit);
1571 
1572 MODULE_AUTHOR( DRIVER_AUTHOR );
1573 MODULE_DESCRIPTION( DRIVER_DESC );
1574 MODULE_VERSION( DRIVER_VERSION );
1575 MODULE_LICENSE("GPL");
1576 
1577 module_param(debug, bool, S_IRUGO | S_IWUSR);
1578 MODULE_PARM_DESC(debug, "Debug enabled or not");
1579 module_param(stats, bool, S_IRUGO | S_IWUSR);
1580 MODULE_PARM_DESC(stats, "Enable statistics or not");
1581 module_param(interval, int, S_IRUGO | S_IWUSR);
1582 MODULE_PARM_DESC(interval, "Overrides interrupt interval");
1583