xref: /linux/drivers/usb/serial/cypress_m8.c (revision 2624f124b3b5d550ab2fbef7ee3bc0e1fed09722)
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 	set_current_state(TASK_INTERRUPTIBLE);
614 	schedule_timeout(timeout);
615 
616 	dbg("%s - stopping urbs", __FUNCTION__);
617 	usb_kill_urb (port->interrupt_in_urb);
618 	usb_kill_urb (port->interrupt_out_urb);
619 
620 	if (port->tty) {
621 		c_cflag = port->tty->termios->c_cflag;
622 		if (c_cflag & HUPCL) {
623 			/* drop dtr and rts */
624 			priv = usb_get_serial_port_data(port);
625 			spin_lock_irqsave(&priv->lock, flags);
626 			priv->line_control = 0;
627 			priv->cmd_ctrl = 1;
628 			spin_unlock_irqrestore(&priv->lock, flags);
629 			cypress_write(port, NULL, 0);
630 		}
631 	}
632 
633 	if (stats)
634 		dev_info (&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
635 		          priv->bytes_in, priv->bytes_out, priv->cmd_count);
636 } /* cypress_close */
637 
638 
639 static int cypress_write(struct usb_serial_port *port, const unsigned char *buf, int count)
640 {
641 	struct cypress_private *priv = usb_get_serial_port_data(port);
642 	unsigned long flags;
643 
644 	dbg("%s - port %d, %d bytes", __FUNCTION__, port->number, count);
645 
646 	/* line control commands, which need to be executed immediately,
647 	   are not put into the buffer for obvious reasons.
648 	 */
649 	if (priv->cmd_ctrl) {
650 		count = 0;
651 		goto finish;
652 	}
653 
654 	if (!count)
655 		return count;
656 
657 	spin_lock_irqsave(&priv->lock, flags);
658 	count = cypress_buf_put(priv->buf, buf, count);
659 	spin_unlock_irqrestore(&priv->lock, flags);
660 
661 finish:
662 	cypress_send(port);
663 
664 	return count;
665 } /* cypress_write */
666 
667 
668 static void cypress_send(struct usb_serial_port *port)
669 {
670 	int count = 0, result, offset, actual_size;
671 	struct cypress_private *priv = usb_get_serial_port_data(port);
672 	unsigned long flags;
673 
674 	dbg("%s - port %d", __FUNCTION__, port->number);
675 	dbg("%s - interrupt out size is %d", __FUNCTION__, port->interrupt_out_size);
676 
677 	spin_lock_irqsave(&priv->lock, flags);
678 	if (priv->write_urb_in_use) {
679 		dbg("%s - can't write, urb in use", __FUNCTION__);
680 		spin_unlock_irqrestore(&priv->lock, flags);
681 		return;
682 	}
683 	spin_unlock_irqrestore(&priv->lock, flags);
684 
685 	/* clear buffer */
686 	memset(port->interrupt_out_urb->transfer_buffer, 0, port->interrupt_out_size);
687 
688 	spin_lock_irqsave(&priv->lock, flags);
689 	switch (port->interrupt_out_size) {
690 		case 32:
691 			/* this is for the CY7C64013... */
692 			offset = 2;
693 			port->interrupt_out_buffer[0] = priv->line_control;
694 			break;
695 		case 8:
696 			/* this is for the CY7C63743... */
697 			offset = 1;
698 			port->interrupt_out_buffer[0] = priv->line_control;
699 			break;
700 		default:
701 			dbg("%s - wrong packet size", __FUNCTION__);
702 			spin_unlock_irqrestore(&priv->lock, flags);
703 			return;
704 	}
705 
706 	if (priv->line_control & CONTROL_RESET)
707 		priv->line_control &= ~CONTROL_RESET;
708 
709 	if (priv->cmd_ctrl) {
710 		priv->cmd_count++;
711 		dbg("%s - line control command being issued", __FUNCTION__);
712 		spin_unlock_irqrestore(&priv->lock, flags);
713 		goto send;
714 	} else
715 		spin_unlock_irqrestore(&priv->lock, flags);
716 
717 	count = cypress_buf_get(priv->buf, &port->interrupt_out_buffer[offset],
718 				port->interrupt_out_size-offset);
719 
720 	if (count == 0) {
721 		return;
722 	}
723 
724 	switch (port->interrupt_out_size) {
725 		case 32:
726 			port->interrupt_out_buffer[1] = count;
727 			break;
728 		case 8:
729 			port->interrupt_out_buffer[0] |= count;
730 	}
731 
732 	dbg("%s - count is %d", __FUNCTION__, count);
733 
734 send:
735 	spin_lock_irqsave(&priv->lock, flags);
736 	priv->write_urb_in_use = 1;
737 	spin_unlock_irqrestore(&priv->lock, flags);
738 
739 	if (priv->cmd_ctrl)
740 		actual_size = 1;
741 	else
742 		actual_size = count + (port->interrupt_out_size == 32 ? 2 : 1);
743 
744 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, port->interrupt_out_size,
745 			      port->interrupt_out_urb->transfer_buffer);
746 
747 	port->interrupt_out_urb->transfer_buffer_length = actual_size;
748 	port->interrupt_out_urb->dev = port->serial->dev;
749 	port->interrupt_out_urb->interval = interval;
750 	result = usb_submit_urb (port->interrupt_out_urb, GFP_ATOMIC);
751 	if (result) {
752 		dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__,
753 			result);
754 		priv->write_urb_in_use = 0;
755 	}
756 
757 	spin_lock_irqsave(&priv->lock, flags);
758 	if (priv->cmd_ctrl) {
759 		priv->cmd_ctrl = 0;
760 	}
761 	priv->bytes_out += count; /* do not count the line control and size bytes */
762 	spin_unlock_irqrestore(&priv->lock, flags);
763 
764 	schedule_work(&port->work);
765 } /* cypress_send */
766 
767 
768 /* returns how much space is available in the soft buffer */
769 static int cypress_write_room(struct usb_serial_port *port)
770 {
771 	struct cypress_private *priv = usb_get_serial_port_data(port);
772 	int room = 0;
773 	unsigned long flags;
774 
775 	dbg("%s - port %d", __FUNCTION__, port->number);
776 
777 	spin_lock_irqsave(&priv->lock, flags);
778 	room = cypress_buf_space_avail(priv->buf);
779 	spin_unlock_irqrestore(&priv->lock, flags);
780 
781 	dbg("%s - returns %d", __FUNCTION__, room);
782 	return room;
783 }
784 
785 
786 static int cypress_tiocmget (struct usb_serial_port *port, struct file *file)
787 {
788 	struct cypress_private *priv = usb_get_serial_port_data(port);
789 	__u8 status, control;
790 	unsigned int result = 0;
791 	unsigned long flags;
792 
793 	dbg("%s - port %d", __FUNCTION__, port->number);
794 
795 	spin_lock_irqsave(&priv->lock, flags);
796 	control = priv->line_control;
797 	status = priv->current_status;
798 	spin_unlock_irqrestore(&priv->lock, flags);
799 
800 	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
801 		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
802 		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
803 		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
804 		| ((status & UART_RI)         ? TIOCM_RI  : 0)
805 		| ((status & UART_CD)         ? TIOCM_CD  : 0);
806 
807 	dbg("%s - result = %x", __FUNCTION__, result);
808 
809 	return result;
810 }
811 
812 
813 static int cypress_tiocmset (struct usb_serial_port *port, struct file *file,
814 			       unsigned int set, unsigned int clear)
815 {
816 	struct cypress_private *priv = usb_get_serial_port_data(port);
817 	unsigned long flags;
818 
819 	dbg("%s - port %d", __FUNCTION__, port->number);
820 
821 	spin_lock_irqsave(&priv->lock, flags);
822 	if (set & TIOCM_RTS)
823 		priv->line_control |= CONTROL_RTS;
824 	if (set & TIOCM_DTR)
825 		priv->line_control |= CONTROL_DTR;
826 	if (clear & TIOCM_RTS)
827 		priv->line_control &= ~CONTROL_RTS;
828 	if (clear & TIOCM_DTR)
829 		priv->line_control &= ~CONTROL_DTR;
830 	spin_unlock_irqrestore(&priv->lock, flags);
831 
832 	priv->cmd_ctrl = 1;
833 	return cypress_write(port, NULL, 0);
834 }
835 
836 
837 static int cypress_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
838 {
839 	struct cypress_private *priv = usb_get_serial_port_data(port);
840 
841 	dbg("%s - port %d, cmd 0x%.4x", __FUNCTION__, port->number, cmd);
842 
843 	switch (cmd) {
844 		case TIOCGSERIAL:
845 			if (copy_to_user((void __user *)arg, port->tty->termios, sizeof(struct termios))) {
846 				return -EFAULT;
847 			}
848 			return (0);
849 			break;
850 		case TIOCSSERIAL:
851 			if (copy_from_user(port->tty->termios, (void __user *)arg, sizeof(struct termios))) {
852 				return -EFAULT;
853 			}
854 			/* here we need to call cypress_set_termios to invoke the new settings */
855 			cypress_set_termios(port, &priv->tmp_termios);
856 			return (0);
857 			break;
858 		/* these are called when setting baud rate from gpsd */
859 		case TCGETS:
860 			if (copy_to_user((void __user *)arg, port->tty->termios, sizeof(struct termios))) {
861 				return -EFAULT;
862 			}
863 			return (0);
864 			break;
865 		case TCSETS:
866 			if (copy_from_user(port->tty->termios, (void __user *)arg, sizeof(struct termios))) {
867 				return -EFAULT;
868 			}
869 			/* here we need to call cypress_set_termios to invoke the new settings */
870 			cypress_set_termios(port, &priv->tmp_termios);
871 			return (0);
872 			break;
873 		/* This code comes from drivers/char/serial.c and ftdi_sio.c */
874 		case TIOCMIWAIT:
875 			while (priv != NULL) {
876 				interruptible_sleep_on(&priv->delta_msr_wait);
877 				/* see if a signal did it */
878 				if (signal_pending(current))
879 					return -ERESTARTSYS;
880 				else {
881 					char diff = priv->diff_status;
882 
883 					if (diff == 0) {
884 						return -EIO; /* no change => error */
885 					}
886 
887 					/* consume all events */
888 					priv->diff_status = 0;
889 
890 					/* return 0 if caller wanted to know about 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 					}
897 					/* otherwise caller can't care less about what happened,
898 					 * and so we continue to wait for more events.
899 					 */
900 				}
901 			}
902 			return 0;
903 			break;
904 		default:
905 			break;
906 	}
907 
908 	dbg("%s - arg not supported - it was 0x%04x - check include/asm/ioctls.h", __FUNCTION__, cmd);
909 
910 	return -ENOIOCTLCMD;
911 } /* cypress_ioctl */
912 
913 
914 static void cypress_set_termios (struct usb_serial_port *port,
915 		struct termios *old_termios)
916 {
917 	struct cypress_private *priv = usb_get_serial_port_data(port);
918 	struct tty_struct *tty;
919 	int data_bits, stop_bits, parity_type, parity_enable;
920 	unsigned cflag, iflag, baud_mask;
921 	unsigned long flags;
922 	__u8 oldlines;
923 	int linechange = 0;
924 
925 	dbg("%s - port %d", __FUNCTION__, port->number);
926 
927 	tty = port->tty;
928 	if ((!tty) || (!tty->termios)) {
929 		dbg("%s - no tty structures", __FUNCTION__);
930 		return;
931 	}
932 
933 	spin_lock_irqsave(&priv->lock, flags);
934 	if (!priv->termios_initialized) {
935 		if (priv->chiptype == CT_EARTHMATE) {
936 			*(tty->termios) = tty_std_termios;
937 			tty->termios->c_cflag = B4800 | CS8 | CREAD | HUPCL |
938 				CLOCAL;
939 		} else if (priv->chiptype == CT_CYPHIDCOM) {
940 			*(tty->termios) = tty_std_termios;
941 			tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL |
942 				CLOCAL;
943 		}
944 		priv->termios_initialized = 1;
945 	}
946 	spin_unlock_irqrestore(&priv->lock, flags);
947 
948 	cflag = tty->termios->c_cflag;
949 	iflag = tty->termios->c_iflag;
950 
951 	/* check if there are new settings */
952 	if (old_termios) {
953 		if ((cflag != old_termios->c_cflag) ||
954 			(RELEVANT_IFLAG(iflag) !=
955 			 RELEVANT_IFLAG(old_termios->c_iflag))) {
956 			dbg("%s - attempting to set new termios settings",
957 					__FUNCTION__);
958 			/* should make a copy of this in case something goes
959 			 * wrong in the function, we can restore it */
960 			spin_lock_irqsave(&priv->lock, flags);
961 			priv->tmp_termios = *(tty->termios);
962 			spin_unlock_irqrestore(&priv->lock, flags);
963 		} else {
964 			dbg("%s - nothing to do, exiting", __FUNCTION__);
965 			return;
966 		}
967 	} else
968 		return;
969 
970 	/* set number of data bits, parity, stop bits */
971 	/* when parity is disabled the parity type bit is ignored */
972 
973 	/* 1 means 2 stop bits, 0 means 1 stop bit */
974 	stop_bits = cflag & CSTOPB ? 1 : 0;
975 
976 	if (cflag & PARENB) {
977 		parity_enable = 1;
978 		/* 1 means odd parity, 0 means even parity */
979 		parity_type = cflag & PARODD ? 1 : 0;
980 	} else
981 		parity_enable = parity_type = 0;
982 
983 	if (cflag & CSIZE) {
984 		switch (cflag & CSIZE) {
985 			case CS5:
986 				data_bits = 0;
987 				break;
988 			case CS6:
989 				data_bits = 1;
990 				break;
991 			case CS7:
992 				data_bits = 2;
993 				break;
994 			case CS8:
995 				data_bits = 3;
996 				break;
997 			default:
998 				err("%s - CSIZE was set, but not CS5-CS8",
999 						__FUNCTION__);
1000 				data_bits = 3;
1001 		}
1002 	} else
1003 		data_bits = 3;
1004 
1005 	spin_lock_irqsave(&priv->lock, flags);
1006 	oldlines = priv->line_control;
1007 	if ((cflag & CBAUD) == B0) {
1008 		/* drop dtr and rts */
1009 		dbg("%s - dropping the lines, baud rate 0bps", __FUNCTION__);
1010 		baud_mask = B0;
1011 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
1012 	} else {
1013 		baud_mask = (cflag & CBAUD);
1014 		switch(baud_mask) {
1015 			case B300:
1016 				dbg("%s - setting baud 300bps", __FUNCTION__);
1017 				break;
1018 			case B600:
1019 				dbg("%s - setting baud 600bps", __FUNCTION__);
1020 				break;
1021 			case B1200:
1022 				dbg("%s - setting baud 1200bps", __FUNCTION__);
1023 				break;
1024 			case B2400:
1025 				dbg("%s - setting baud 2400bps", __FUNCTION__);
1026 				break;
1027 			case B4800:
1028 				dbg("%s - setting baud 4800bps", __FUNCTION__);
1029 				break;
1030 			case B9600:
1031 				dbg("%s - setting baud 9600bps", __FUNCTION__);
1032 				break;
1033 			case B19200:
1034 				dbg("%s - setting baud 19200bps", __FUNCTION__);
1035 				break;
1036 			case B38400:
1037 				dbg("%s - setting baud 38400bps", __FUNCTION__);
1038 				break;
1039 			case B57600:
1040 				dbg("%s - setting baud 57600bps", __FUNCTION__);
1041 				break;
1042 			case B115200:
1043 				dbg("%s - setting baud 115200bps", __FUNCTION__);
1044 				break;
1045 			default:
1046 				dbg("%s - unknown masked baud rate", __FUNCTION__);
1047 		}
1048 		priv->line_control = (CONTROL_DTR | CONTROL_RTS);
1049 	}
1050 	spin_unlock_irqrestore(&priv->lock, flags);
1051 
1052 	dbg("%s - sending %d stop_bits, %d parity_enable, %d parity_type, "
1053 			"%d data_bits (+5)", __FUNCTION__, stop_bits,
1054 			parity_enable, parity_type, data_bits);
1055 
1056 	cypress_serial_control(port, baud_mask, data_bits, stop_bits,
1057 			parity_enable, parity_type, 0, CYPRESS_SET_CONFIG);
1058 
1059 	/* we perform a CYPRESS_GET_CONFIG so that the current settings are
1060 	 * filled into the private structure this should confirm that all is
1061 	 * working if it returns what we just set */
1062 	cypress_serial_control(port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
1063 
1064 	/* Here we can define custom tty settings for devices; the main tty
1065 	 * termios flag base comes from empeg.c */
1066 
1067 	spin_lock_irqsave(&priv->lock, flags);
1068 	if ( (priv->chiptype == CT_EARTHMATE) && (priv->baud_rate == 4800) ) {
1069 		dbg("Using custom termios settings for a baud rate of "
1070 				"4800bps.");
1071 		/* define custom termios settings for NMEA protocol */
1072 
1073 		tty->termios->c_iflag /* input modes - */
1074 			&= ~(IGNBRK  /* disable ignore break */
1075 			| BRKINT     /* disable break causes interrupt */
1076 			| PARMRK     /* disable mark parity errors */
1077 			| ISTRIP     /* disable clear high bit of input char */
1078 			| INLCR      /* disable translate NL to CR */
1079 			| IGNCR      /* disable ignore CR */
1080 			| ICRNL      /* disable translate CR to NL */
1081 			| IXON);     /* disable enable XON/XOFF flow control */
1082 
1083 		tty->termios->c_oflag /* output modes */
1084 			&= ~OPOST;    /* disable postprocess output char */
1085 
1086 		tty->termios->c_lflag /* line discipline modes */
1087 			&= ~(ECHO     /* disable echo input characters */
1088 			| ECHONL      /* disable echo new line */
1089 			| ICANON      /* disable erase, kill, werase, and rprnt
1090 					 special characters */
1091 			| ISIG        /* disable interrupt, quit, and suspend
1092 					 special characters */
1093 			| IEXTEN);    /* disable non-POSIX special characters */
1094 	} /* CT_CYPHIDCOM: Application should handle this for device */
1095 
1096 	linechange = (priv->line_control != oldlines);
1097 	spin_unlock_irqrestore(&priv->lock, flags);
1098 
1099 	/* if necessary, set lines */
1100 	if (linechange) {
1101 		priv->cmd_ctrl = 1;
1102 		cypress_write(port, NULL, 0);
1103 	}
1104 } /* cypress_set_termios */
1105 
1106 
1107 /* returns amount of data still left in soft buffer */
1108 static int cypress_chars_in_buffer(struct usb_serial_port *port)
1109 {
1110 	struct cypress_private *priv = usb_get_serial_port_data(port);
1111 	int chars = 0;
1112 	unsigned long flags;
1113 
1114 	dbg("%s - port %d", __FUNCTION__, port->number);
1115 
1116 	spin_lock_irqsave(&priv->lock, flags);
1117 	chars = cypress_buf_data_avail(priv->buf);
1118 	spin_unlock_irqrestore(&priv->lock, flags);
1119 
1120 	dbg("%s - returns %d", __FUNCTION__, chars);
1121 	return chars;
1122 }
1123 
1124 
1125 static void cypress_throttle (struct usb_serial_port *port)
1126 {
1127 	struct cypress_private *priv = usb_get_serial_port_data(port);
1128 	unsigned long flags;
1129 
1130 	dbg("%s - port %d", __FUNCTION__, port->number);
1131 
1132 	spin_lock_irqsave(&priv->lock, flags);
1133 	priv->rx_flags = THROTTLED;
1134 	spin_unlock_irqrestore(&priv->lock, flags);
1135 }
1136 
1137 
1138 static void cypress_unthrottle (struct usb_serial_port *port)
1139 {
1140 	struct cypress_private *priv = usb_get_serial_port_data(port);
1141 	int actually_throttled, result;
1142 	unsigned long flags;
1143 
1144 	dbg("%s - port %d", __FUNCTION__, port->number);
1145 
1146 	spin_lock_irqsave(&priv->lock, flags);
1147 	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
1148 	priv->rx_flags = 0;
1149 	spin_unlock_irqrestore(&priv->lock, flags);
1150 
1151 	if (actually_throttled) {
1152 		port->interrupt_in_urb->dev = port->serial->dev;
1153 
1154 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1155 		if (result)
1156 			dev_err(&port->dev, "%s - failed submitting read urb, "
1157 					"error %d\n", __FUNCTION__, result);
1158 	}
1159 }
1160 
1161 
1162 static void cypress_read_int_callback(struct urb *urb, struct pt_regs *regs)
1163 {
1164 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
1165 	struct cypress_private *priv = usb_get_serial_port_data(port);
1166 	struct tty_struct *tty;
1167 	unsigned char *data = urb->transfer_buffer;
1168 	unsigned long flags;
1169 	char tty_flag = TTY_NORMAL;
1170 	int havedata = 0;
1171 	int bytes = 0;
1172 	int result;
1173 	int i = 0;
1174 
1175 	dbg("%s - port %d", __FUNCTION__, port->number);
1176 
1177 	if (urb->status) {
1178 		dbg("%s - nonzero read status received: %d", __FUNCTION__,
1179 				urb->status);
1180 		return;
1181 	}
1182 
1183 	spin_lock_irqsave(&priv->lock, flags);
1184 	if (priv->rx_flags & THROTTLED) {
1185 		dbg("%s - now throttling", __FUNCTION__);
1186 		priv->rx_flags |= ACTUALLY_THROTTLED;
1187 		spin_unlock_irqrestore(&priv->lock, flags);
1188 		return;
1189 	}
1190 	spin_unlock_irqrestore(&priv->lock, flags);
1191 
1192 	tty = port->tty;
1193 	if (!tty) {
1194 		dbg("%s - bad tty pointer - exiting", __FUNCTION__);
1195 		return;
1196 	}
1197 
1198 	spin_lock_irqsave(&priv->lock, flags);
1199 	switch(urb->actual_length) {
1200 		case 32:
1201 			/* This is for the CY7C64013... */
1202 			priv->current_status = data[0] & 0xF8;
1203 			bytes = data[1] + 2;
1204 			i = 2;
1205 			if (bytes > 2)
1206 				havedata = 1;
1207 			break;
1208 		case 8:
1209 			/* This is for the CY7C63743... */
1210 			priv->current_status = data[0] & 0xF8;
1211 			bytes = (data[0] & 0x07) + 1;
1212 			i = 1;
1213 			if (bytes > 1)
1214 				havedata = 1;
1215 			break;
1216 		default:
1217 			dbg("%s - wrong packet size - received %d bytes",
1218 					__FUNCTION__, urb->actual_length);
1219 			spin_unlock_irqrestore(&priv->lock, flags);
1220 			goto continue_read;
1221 	}
1222 	spin_unlock_irqrestore(&priv->lock, flags);
1223 
1224 	usb_serial_debug_data (debug, &port->dev, __FUNCTION__,
1225 			urb->actual_length, data);
1226 
1227 	spin_lock_irqsave(&priv->lock, flags);
1228 	/* check to see if status has changed */
1229 	if (priv != NULL) {
1230 		if (priv->current_status != priv->prev_status) {
1231 			priv->diff_status |= priv->current_status ^
1232 				priv->prev_status;
1233 			wake_up_interruptible(&priv->delta_msr_wait);
1234 			priv->prev_status = priv->current_status;
1235 		}
1236 	}
1237 	spin_unlock_irqrestore(&priv->lock, flags);
1238 
1239 	/* hangup, as defined in acm.c... this might be a bad place for it
1240 	 * though */
1241 	if (tty && !(tty->termios->c_cflag & CLOCAL) &&
1242 			!(priv->current_status & UART_CD)) {
1243 		dbg("%s - calling hangup", __FUNCTION__);
1244 		tty_hangup(tty);
1245 		goto continue_read;
1246 	}
1247 
1248 	/* There is one error bit... I'm assuming it is a parity error
1249 	 * indicator as the generic firmware will set this bit to 1 if a
1250 	 * parity error occurs.
1251 	 * I can not find reference to any other error events. */
1252 	spin_lock_irqsave(&priv->lock, flags);
1253 	if (priv->current_status & CYP_ERROR) {
1254 		spin_unlock_irqrestore(&priv->lock, flags);
1255 		tty_flag = TTY_PARITY;
1256 		dbg("%s - Parity Error detected", __FUNCTION__);
1257 	} else
1258 		spin_unlock_irqrestore(&priv->lock, flags);
1259 
1260 	/* process read if there is data other than line status */
1261 	if (tty && (bytes > i)) {
1262 		for (; i < bytes ; ++i) {
1263 			dbg("pushing byte number %d - %d - %c", i, data[i],
1264 					data[i]);
1265 			if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
1266 				tty_flip_buffer_push(tty);
1267 			}
1268 			tty_insert_flip_char(tty, data[i], tty_flag);
1269 		}
1270 		tty_flip_buffer_push(port->tty);
1271 	}
1272 
1273 	spin_lock_irqsave(&priv->lock, flags);
1274 	/* control and status byte(s) are also counted */
1275 	priv->bytes_in += bytes;
1276 	spin_unlock_irqrestore(&priv->lock, flags);
1277 
1278 continue_read:
1279 
1280 	/* Continue trying to always read... unless the port has closed. */
1281 
1282 	if (port->open_count > 0) {
1283 		usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1284 				usb_rcvintpipe(port->serial->dev,
1285 					port->interrupt_in_endpointAddress),
1286 				port->interrupt_in_urb->transfer_buffer,
1287 				port->interrupt_in_urb->transfer_buffer_length,
1288 				cypress_read_int_callback, port, interval);
1289 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1290 		if (result)
1291 			dev_err(&urb->dev->dev, "%s - failed resubmitting "
1292 					"read urb, error %d\n", __FUNCTION__,
1293 					result);
1294 	}
1295 
1296 	return;
1297 } /* cypress_read_int_callback */
1298 
1299 
1300 static void cypress_write_int_callback(struct urb *urb, struct pt_regs *regs)
1301 {
1302 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
1303 	struct cypress_private *priv = usb_get_serial_port_data(port);
1304 	int result;
1305 
1306 	dbg("%s - port %d", __FUNCTION__, port->number);
1307 
1308 	switch (urb->status) {
1309 		case 0:
1310 			/* success */
1311 			break;
1312 		case -ECONNRESET:
1313 		case -ENOENT:
1314 		case -ESHUTDOWN:
1315 			/* this urb is terminated, clean up */
1316 			dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
1317 			priv->write_urb_in_use = 0;
1318 			return;
1319 		case -EPIPE: /* no break needed */
1320 			usb_clear_halt(port->serial->dev, 0x02);
1321 		default:
1322 			/* error in the urb, so we have to resubmit it */
1323 			dbg("%s - Overflow in write", __FUNCTION__);
1324 			dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
1325 			port->interrupt_out_urb->transfer_buffer_length = 1;
1326 			port->interrupt_out_urb->dev = port->serial->dev;
1327 			result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
1328 			if (result)
1329 				dev_err(&urb->dev->dev, "%s - failed resubmitting write urb, error %d\n",
1330 					__FUNCTION__, result);
1331 			else
1332 				return;
1333 	}
1334 
1335 	priv->write_urb_in_use = 0;
1336 
1337 	/* send any buffered data */
1338 	cypress_send(port);
1339 }
1340 
1341 
1342 /*****************************************************************************
1343  * Write buffer functions - buffering code from pl2303 used
1344  *****************************************************************************/
1345 
1346 /*
1347  * cypress_buf_alloc
1348  *
1349  * Allocate a circular buffer and all associated memory.
1350  */
1351 
1352 static struct cypress_buf *cypress_buf_alloc(unsigned int size)
1353 {
1354 
1355 	struct cypress_buf *cb;
1356 
1357 
1358 	if (size == 0)
1359 		return NULL;
1360 
1361 	cb = (struct cypress_buf *)kmalloc(sizeof(struct cypress_buf), GFP_KERNEL);
1362 	if (cb == NULL)
1363 		return NULL;
1364 
1365 	cb->buf_buf = kmalloc(size, GFP_KERNEL);
1366 	if (cb->buf_buf == NULL) {
1367 		kfree(cb);
1368 		return NULL;
1369 	}
1370 
1371 	cb->buf_size = size;
1372 	cb->buf_get = cb->buf_put = cb->buf_buf;
1373 
1374 	return cb;
1375 
1376 }
1377 
1378 
1379 /*
1380  * cypress_buf_free
1381  *
1382  * Free the buffer and all associated memory.
1383  */
1384 
1385 static void cypress_buf_free(struct cypress_buf *cb)
1386 {
1387 	if (cb) {
1388 		kfree(cb->buf_buf);
1389 		kfree(cb);
1390 	}
1391 }
1392 
1393 
1394 /*
1395  * cypress_buf_clear
1396  *
1397  * Clear out all data in the circular buffer.
1398  */
1399 
1400 static void cypress_buf_clear(struct cypress_buf *cb)
1401 {
1402 	if (cb != NULL)
1403 		cb->buf_get = cb->buf_put;
1404 		/* equivalent to a get of all data available */
1405 }
1406 
1407 
1408 /*
1409  * cypress_buf_data_avail
1410  *
1411  * Return the number of bytes of data available in the circular
1412  * buffer.
1413  */
1414 
1415 static unsigned int cypress_buf_data_avail(struct cypress_buf *cb)
1416 {
1417 	if (cb != NULL)
1418 		return ((cb->buf_size + cb->buf_put - cb->buf_get) % cb->buf_size);
1419 	else
1420 		return 0;
1421 }
1422 
1423 
1424 /*
1425  * cypress_buf_space_avail
1426  *
1427  * Return the number of bytes of space available in the circular
1428  * buffer.
1429  */
1430 
1431 static unsigned int cypress_buf_space_avail(struct cypress_buf *cb)
1432 {
1433 	if (cb != NULL)
1434 		return ((cb->buf_size + cb->buf_get - cb->buf_put - 1) % cb->buf_size);
1435 	else
1436 		return 0;
1437 }
1438 
1439 
1440 /*
1441  * cypress_buf_put
1442  *
1443  * Copy data data from a user buffer and put it into the circular buffer.
1444  * Restrict to the amount of space available.
1445  *
1446  * Return the number of bytes copied.
1447  */
1448 
1449 static unsigned int cypress_buf_put(struct cypress_buf *cb, const char *buf,
1450 	unsigned int count)
1451 {
1452 
1453 	unsigned int len;
1454 
1455 
1456 	if (cb == NULL)
1457 		return 0;
1458 
1459 	len  = cypress_buf_space_avail(cb);
1460 	if (count > len)
1461 		count = len;
1462 
1463 	if (count == 0)
1464 		return 0;
1465 
1466 	len = cb->buf_buf + cb->buf_size - cb->buf_put;
1467 	if (count > len) {
1468 		memcpy(cb->buf_put, buf, len);
1469 		memcpy(cb->buf_buf, buf+len, count - len);
1470 		cb->buf_put = cb->buf_buf + count - len;
1471 	} else {
1472 		memcpy(cb->buf_put, buf, count);
1473 		if (count < len)
1474 			cb->buf_put += count;
1475 		else /* count == len */
1476 			cb->buf_put = cb->buf_buf;
1477 	}
1478 
1479 	return count;
1480 
1481 }
1482 
1483 
1484 /*
1485  * cypress_buf_get
1486  *
1487  * Get data from the circular buffer and copy to the given buffer.
1488  * Restrict to the amount of data available.
1489  *
1490  * Return the number of bytes copied.
1491  */
1492 
1493 static unsigned int cypress_buf_get(struct cypress_buf *cb, char *buf,
1494 	unsigned int count)
1495 {
1496 
1497 	unsigned int len;
1498 
1499 
1500 	if (cb == NULL)
1501 		return 0;
1502 
1503 	len = cypress_buf_data_avail(cb);
1504 	if (count > len)
1505 		count = len;
1506 
1507 	if (count == 0)
1508 		return 0;
1509 
1510 	len = cb->buf_buf + cb->buf_size - cb->buf_get;
1511 	if (count > len) {
1512 		memcpy(buf, cb->buf_get, len);
1513 		memcpy(buf+len, cb->buf_buf, count - len);
1514 		cb->buf_get = cb->buf_buf + count - len;
1515 	} else {
1516 		memcpy(buf, cb->buf_get, count);
1517 		if (count < len)
1518 			cb->buf_get += count;
1519 		else /* count == len */
1520 			cb->buf_get = cb->buf_buf;
1521 	}
1522 
1523 	return count;
1524 
1525 }
1526 
1527 /*****************************************************************************
1528  * Module functions
1529  *****************************************************************************/
1530 
1531 static int __init cypress_init(void)
1532 {
1533 	int retval;
1534 
1535 	dbg("%s", __FUNCTION__);
1536 
1537 	retval = usb_serial_register(&cypress_earthmate_device);
1538 	if (retval)
1539 		goto failed_em_register;
1540 	retval = usb_serial_register(&cypress_hidcom_device);
1541 	if (retval)
1542 		goto failed_hidcom_register;
1543 	retval = usb_register(&cypress_driver);
1544 	if (retval)
1545 		goto failed_usb_register;
1546 
1547 	info(DRIVER_DESC " " DRIVER_VERSION);
1548 	return 0;
1549 failed_usb_register:
1550 	usb_deregister(&cypress_driver);
1551 failed_hidcom_register:
1552 	usb_serial_deregister(&cypress_hidcom_device);
1553 failed_em_register:
1554 	usb_serial_deregister(&cypress_earthmate_device);
1555 
1556 	return retval;
1557 }
1558 
1559 
1560 static void __exit cypress_exit (void)
1561 {
1562 	dbg("%s", __FUNCTION__);
1563 
1564 	usb_deregister (&cypress_driver);
1565 	usb_serial_deregister (&cypress_earthmate_device);
1566 	usb_serial_deregister (&cypress_hidcom_device);
1567 }
1568 
1569 
1570 module_init(cypress_init);
1571 module_exit(cypress_exit);
1572 
1573 MODULE_AUTHOR( DRIVER_AUTHOR );
1574 MODULE_DESCRIPTION( DRIVER_DESC );
1575 MODULE_VERSION( DRIVER_VERSION );
1576 MODULE_LICENSE("GPL");
1577 
1578 module_param(debug, bool, S_IRUGO | S_IWUSR);
1579 MODULE_PARM_DESC(debug, "Debug enabled or not");
1580 module_param(stats, bool, S_IRUGO | S_IWUSR);
1581 MODULE_PARM_DESC(stats, "Enable statistics or not");
1582 module_param(interval, int, S_IRUGO | S_IWUSR);
1583 MODULE_PARM_DESC(interval, "Overrides interrupt interval");
1584