xref: /linux/drivers/usb/serial/cypress_m8.c (revision 776cfebb430c7b22c208b1b17add97f354d97cab)
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 	{ }						/* Terminating entry */
93 };
94 
95 static struct usb_device_id id_table_cyphidcomrs232 [] = {
96 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
97 	{ }						/* Terminating entry */
98 };
99 
100 static struct usb_device_id id_table_combined [] = {
101 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
102 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
103 	{ }						/* Terminating entry */
104 };
105 
106 MODULE_DEVICE_TABLE (usb, id_table_combined);
107 
108 static struct usb_driver cypress_driver = {
109 	.name =		"cypress",
110 	.probe =	usb_serial_probe,
111 	.disconnect =	usb_serial_disconnect,
112 	.id_table =	id_table_combined,
113 };
114 
115 struct cypress_private {
116 	spinlock_t lock;		   /* private lock */
117 	int chiptype;			   /* identifier of device, for quirks/etc */
118 	int bytes_in;			   /* used for statistics */
119 	int bytes_out;			   /* used for statistics */
120 	int cmd_count;			   /* used for statistics */
121 	int cmd_ctrl;			   /* always set this to 1 before issuing a command */
122 	struct cypress_buf *buf;	   /* write buffer */
123 	int write_urb_in_use;		   /* write urb in use indicator */
124 	int termios_initialized;
125 	__u8 line_control;	   	   /* holds dtr / rts value */
126 	__u8 current_status;	   	   /* received from last read - info on dsr,cts,cd,ri,etc */
127 	__u8 current_config;	   	   /* stores the current configuration byte */
128 	__u8 rx_flags;			   /* throttling - used from whiteheat/ftdi_sio */
129 	int baud_rate;			   /* stores current baud rate in integer form */
130 	int cbr_mask;			   /* stores current baud rate in masked form */
131 	int isthrottled;		   /* if throttled, discard reads */
132 	wait_queue_head_t delta_msr_wait;  /* used for TIOCMIWAIT */
133 	char prev_status, diff_status;	   /* used for TIOCMIWAIT */
134 	/* we pass a pointer to this as the arguement sent to cypress_set_termios old_termios */
135 	struct termios tmp_termios; 	   /* stores the old termios settings */
136 };
137 
138 /* write buffer structure */
139 struct cypress_buf {
140 	unsigned int	buf_size;
141 	char		*buf_buf;
142 	char		*buf_get;
143 	char		*buf_put;
144 };
145 
146 /* function prototypes for the Cypress USB to serial device */
147 static int  cypress_earthmate_startup	(struct usb_serial *serial);
148 static int  cypress_hidcom_startup	(struct usb_serial *serial);
149 static void cypress_shutdown		(struct usb_serial *serial);
150 static int  cypress_open		(struct usb_serial_port *port, struct file *filp);
151 static void cypress_close		(struct usb_serial_port *port, struct file *filp);
152 static int  cypress_write		(struct usb_serial_port *port, const unsigned char *buf, int count);
153 static void cypress_send		(struct usb_serial_port *port);
154 static int  cypress_write_room		(struct usb_serial_port *port);
155 static int  cypress_ioctl		(struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg);
156 static void cypress_set_termios		(struct usb_serial_port *port, struct termios * old);
157 static int  cypress_tiocmget		(struct usb_serial_port *port, struct file *file);
158 static int  cypress_tiocmset		(struct usb_serial_port *port, struct file *file, unsigned int set, unsigned int clear);
159 static int  cypress_chars_in_buffer	(struct usb_serial_port *port);
160 static void cypress_throttle		(struct usb_serial_port *port);
161 static void cypress_unthrottle		(struct usb_serial_port *port);
162 static void cypress_read_int_callback	(struct urb *urb, struct pt_regs *regs);
163 static void cypress_write_int_callback	(struct urb *urb, struct pt_regs *regs);
164 /* baud helper functions */
165 static int	 mask_to_rate		(unsigned mask);
166 static unsigned  rate_to_mask		(int rate);
167 /* write buffer functions */
168 static struct cypress_buf *cypress_buf_alloc(unsigned int size);
169 static void 		  cypress_buf_free(struct cypress_buf *cb);
170 static void		  cypress_buf_clear(struct cypress_buf *cb);
171 static unsigned int	  cypress_buf_data_avail(struct cypress_buf *cb);
172 static unsigned int	  cypress_buf_space_avail(struct cypress_buf *cb);
173 static unsigned int	  cypress_buf_put(struct cypress_buf *cb, const char *buf, unsigned int count);
174 static unsigned int	  cypress_buf_get(struct cypress_buf *cb, char *buf, unsigned int count);
175 
176 
177 static struct usb_serial_device_type cypress_earthmate_device = {
178 	.owner =			THIS_MODULE,
179 	.name =				"DeLorme Earthmate USB",
180 	.short_name =			"earthmate",
181 	.id_table =			id_table_earthmate,
182 	.num_interrupt_in = 		1,
183 	.num_interrupt_out =		1,
184 	.num_bulk_in =			NUM_DONT_CARE,
185 	.num_bulk_out =			NUM_DONT_CARE,
186 	.num_ports =			1,
187 	.attach =			cypress_earthmate_startup,
188 	.shutdown =			cypress_shutdown,
189 	.open =				cypress_open,
190 	.close =			cypress_close,
191 	.write =			cypress_write,
192 	.write_room =			cypress_write_room,
193 	.ioctl =			cypress_ioctl,
194 	.set_termios =			cypress_set_termios,
195 	.tiocmget =			cypress_tiocmget,
196 	.tiocmset =			cypress_tiocmset,
197 	.chars_in_buffer =		cypress_chars_in_buffer,
198 	.throttle =		 	cypress_throttle,
199 	.unthrottle =			cypress_unthrottle,
200 	.read_int_callback =		cypress_read_int_callback,
201 	.write_int_callback =		cypress_write_int_callback,
202 };
203 
204 static struct usb_serial_device_type cypress_hidcom_device = {
205 	.owner =			THIS_MODULE,
206 	.name =				"HID->COM RS232 Adapter",
207 	.short_name =			"cyphidcom",
208 	.id_table =			id_table_cyphidcomrs232,
209 	.num_interrupt_in =		1,
210 	.num_interrupt_out =		1,
211 	.num_bulk_in =			NUM_DONT_CARE,
212 	.num_bulk_out =			NUM_DONT_CARE,
213 	.num_ports =			1,
214 	.attach =			cypress_hidcom_startup,
215 	.shutdown =			cypress_shutdown,
216 	.open =				cypress_open,
217 	.close =			cypress_close,
218 	.write =			cypress_write,
219 	.write_room =			cypress_write_room,
220 	.ioctl =			cypress_ioctl,
221 	.set_termios =			cypress_set_termios,
222 	.tiocmget =			cypress_tiocmget,
223 	.tiocmset =			cypress_tiocmset,
224 	.chars_in_buffer =		cypress_chars_in_buffer,
225 	.throttle =			cypress_throttle,
226 	.unthrottle =			cypress_unthrottle,
227 	.read_int_callback =		cypress_read_int_callback,
228 	.write_int_callback =		cypress_write_int_callback,
229 };
230 
231 
232 /*****************************************************************************
233  * Cypress serial helper functions
234  *****************************************************************************/
235 
236 
237 /* This function can either set or retrieve the current serial line settings */
238 static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_mask, int data_bits, int stop_bits,
239 				   int parity_enable, int parity_type, int reset, int cypress_request_type)
240 {
241 	int new_baudrate = 0, retval = 0, tries = 0;
242 	struct cypress_private *priv;
243 	__u8 feature_buffer[8];
244 	unsigned long flags;
245 
246 	dbg("%s", __FUNCTION__);
247 
248 	priv = usb_get_serial_port_data(port);
249 
250 	switch(cypress_request_type) {
251 		case CYPRESS_SET_CONFIG:
252 
253 			/*
254 			 * The general purpose firmware for the Cypress M8 allows for a maximum speed
255  			 * of 57600bps (I have no idea whether DeLorme chose to use the general purpose
256 			 * firmware or not), if you need to modify this speed setting for your own
257 			 * project please add your own chiptype and modify the code likewise.  The
258 			 * Cypress HID->COM device will work successfully up to 115200bps (but the
259 			 * actual throughput is around 3kBps).
260 			 */
261 			if (baud_mask != priv->cbr_mask) {
262 				dbg("%s - baud rate is changing", __FUNCTION__);
263 				if ( priv->chiptype == CT_EARTHMATE ) {
264 					/* 300 and 600 baud rates are supported under the generic firmware,
265 					 * but are not used with NMEA and SiRF protocols */
266 
267 					if ( (baud_mask == B300) || (baud_mask == B600) ) {
268 						err("%s - failed setting baud rate, unsupported speed",
269 						    __FUNCTION__);
270 						new_baudrate = priv->baud_rate;
271 					} else if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
272 						err("%s - failed setting baud rate, unsupported speed",
273 						    __FUNCTION__);
274 						new_baudrate = priv->baud_rate;
275 					}
276 				} else if (priv->chiptype == CT_CYPHIDCOM) {
277 					if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
278 						err("%s - failed setting baud rate, unsupported speed",
279 						    __FUNCTION__);
280 						new_baudrate = priv->baud_rate;
281 					}
282 				} else if (priv->chiptype == CT_GENERIC) {
283 					if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
284 						err("%s - failed setting baud rate, unsupported speed",
285 						    __FUNCTION__);
286 						new_baudrate = priv->baud_rate;
287 					}
288 				} else {
289 					info("%s - please define your chiptype", __FUNCTION__);
290 					new_baudrate = priv->baud_rate;
291 				}
292 			} else {  /* baud rate not changing, keep the old */
293 				new_baudrate = priv->baud_rate;
294 			}
295 			dbg("%s - baud rate is being sent as %d", __FUNCTION__, new_baudrate);
296 
297 			memset(feature_buffer, 0, 8);
298 			/* fill the feature_buffer with new configuration */
299 			*((u_int32_t *)feature_buffer) = new_baudrate;
300 
301 			feature_buffer[4] |= data_bits;   /* assign data bits in 2 bit space ( max 3 ) */
302 			/* 1 bit gap */
303 			feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
304 			feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
305 			feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
306 			/* 1 bit gap */
307 			feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
308 
309 			dbg("%s - device is being sent this feature report:", __FUNCTION__);
310 			dbg("%s - %02X - %02X - %02X - %02X - %02X", __FUNCTION__, feature_buffer[0], feature_buffer[1],
311 		            feature_buffer[2], feature_buffer[3], feature_buffer[4]);
312 
313 			do {
314 			retval = usb_control_msg (port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
315 					  	  HID_REQ_SET_REPORT, USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
316 						  	  0x0300, 0, feature_buffer, 8, 500);
317 
318 				if (tries++ >= 3)
319 					break;
320 
321 				if (retval == EPIPE)
322 					usb_clear_halt(port->serial->dev, 0x00);
323 			} while (retval != 8 && retval != ENODEV);
324 
325 			if (retval != 8)
326 				err("%s - failed sending serial line settings - %d", __FUNCTION__, retval);
327 			else {
328 				spin_lock_irqsave(&priv->lock, flags);
329 				priv->baud_rate = new_baudrate;
330 				priv->cbr_mask = baud_mask;
331 				priv->current_config = feature_buffer[4];
332 				spin_unlock_irqrestore(&priv->lock, flags);
333 			}
334 		break;
335 		case CYPRESS_GET_CONFIG:
336 			dbg("%s - retreiving serial line settings", __FUNCTION__);
337 			/* set initial values in feature buffer */
338 			memset(feature_buffer, 0, 8);
339 
340 			do {
341 			retval = usb_control_msg (port->serial->dev, usb_rcvctrlpipe(port->serial->dev, 0),
342 						  HID_REQ_GET_REPORT, USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
343 							  0x0300, 0, feature_buffer, 8, 500);
344 
345 				if (tries++ >= 3)
346 					break;
347 
348 				if (retval == EPIPE)
349 					usb_clear_halt(port->serial->dev, 0x00);
350 			} while (retval != 5 && retval != ENODEV);
351 
352 			if (retval != 5) {
353 				err("%s - failed to retreive serial line settings - %d", __FUNCTION__, retval);
354 				return retval;
355 			} else {
356 				spin_lock_irqsave(&priv->lock, flags);
357 
358 				/* store the config in one byte, and later use bit masks to check values */
359 				priv->current_config = feature_buffer[4];
360 				priv->baud_rate = *((u_int32_t *)feature_buffer);
361 
362 				if ( (priv->cbr_mask = rate_to_mask(priv->baud_rate)) == 0x40)
363 					dbg("%s - failed setting the baud mask (not defined)", __FUNCTION__);
364 				spin_unlock_irqrestore(&priv->lock, flags);
365 			}
366 	}
367 	spin_lock_irqsave(&priv->lock, flags);
368 	++priv->cmd_count;
369 	spin_unlock_irqrestore(&priv->lock, flags);
370 
371 	return retval;
372 } /* cypress_serial_control */
373 
374 
375 /* given a baud mask, it will return integer baud on success */
376 static int mask_to_rate (unsigned mask)
377 {
378 	int rate;
379 
380 	switch (mask) {
381 		case B0: rate = 0; break;
382 		case B300: rate = 300; break;
383 		case B600: rate = 600; break;
384 		case B1200: rate = 1200; break;
385 		case B2400: rate = 2400; break;
386 		case B4800: rate = 4800; break;
387 		case B9600: rate = 9600; break;
388 		case B19200: rate = 19200; break;
389 		case B38400: rate = 38400; break;
390 		case B57600: rate = 57600; break;
391 		case B115200: rate = 115200; break;
392 		default: rate = -1;
393 	}
394 
395 	return rate;
396 }
397 
398 
399 static unsigned rate_to_mask (int rate)
400 {
401 	unsigned mask;
402 
403 	switch (rate) {
404 		case 0: mask = B0; break;
405 		case 300: mask = B300; break;
406 		case 600: mask = B600; break;
407 		case 1200: mask = B1200; break;
408 		case 2400: mask = B2400; break;
409 		case 4800: mask = B4800; break;
410 		case 9600: mask = B9600; break;
411 		case 19200: mask = B19200; break;
412 		case 38400: mask = B38400; break;
413 		case 57600: mask = B57600; break;
414 		case 115200: mask = B115200; break;
415 		default: mask = 0x40;
416 	}
417 
418 	return mask;
419 }
420 /*****************************************************************************
421  * Cypress serial driver functions
422  *****************************************************************************/
423 
424 
425 static int generic_startup (struct usb_serial *serial)
426 {
427 	struct cypress_private *priv;
428 
429 	dbg("%s - port %d", __FUNCTION__, serial->port[0]->number);
430 
431 	priv = kmalloc(sizeof (struct cypress_private), GFP_KERNEL);
432 	if (!priv)
433 		return -ENOMEM;
434 
435 	memset(priv, 0x00, sizeof (struct cypress_private));
436 	spin_lock_init(&priv->lock);
437 	priv->buf = cypress_buf_alloc(CYPRESS_BUF_SIZE);
438 	if (priv->buf == NULL) {
439 		kfree(priv);
440 		return -ENOMEM;
441 	}
442 	init_waitqueue_head(&priv->delta_msr_wait);
443 
444 	usb_reset_configuration (serial->dev);
445 
446 	interval = 1;
447 	priv->cmd_ctrl = 0;
448 	priv->line_control = 0;
449 	priv->termios_initialized = 0;
450 	priv->rx_flags = 0;
451 	priv->cbr_mask = B300;
452 	usb_set_serial_port_data(serial->port[0], priv);
453 
454 	return (0);
455 }
456 
457 
458 static int cypress_earthmate_startup (struct usb_serial *serial)
459 {
460 	struct cypress_private *priv;
461 
462 	dbg("%s", __FUNCTION__);
463 
464 	if (generic_startup(serial)) {
465 		dbg("%s - Failed setting up port %d", __FUNCTION__, serial->port[0]->number);
466 		return 1;
467 	}
468 
469 	priv = usb_get_serial_port_data(serial->port[0]);
470 	priv->chiptype = CT_EARTHMATE;
471 
472 	return (0);
473 } /* cypress_earthmate_startup */
474 
475 
476 static int cypress_hidcom_startup (struct usb_serial *serial)
477 {
478 	struct cypress_private *priv;
479 
480 	dbg("%s", __FUNCTION__);
481 
482 	if (generic_startup(serial)) {
483 		dbg("%s - Failed setting up port %d", __FUNCTION__, serial->port[0]->number);
484 		return 1;
485 	}
486 
487 	priv = usb_get_serial_port_data(serial->port[0]);
488 	priv->chiptype = CT_CYPHIDCOM;
489 
490 	return (0);
491 } /* cypress_hidcom_startup */
492 
493 
494 static void cypress_shutdown (struct usb_serial *serial)
495 {
496 	struct cypress_private *priv;
497 
498 	dbg ("%s - port %d", __FUNCTION__, serial->port[0]->number);
499 
500 	/* all open ports are closed at this point */
501 
502 	priv = usb_get_serial_port_data(serial->port[0]);
503 
504 	if (priv) {
505 		cypress_buf_free(priv->buf);
506 		kfree(priv);
507 		usb_set_serial_port_data(serial->port[0], NULL);
508 	}
509 }
510 
511 
512 static int cypress_open (struct usb_serial_port *port, struct file *filp)
513 {
514 	struct cypress_private *priv = usb_get_serial_port_data(port);
515 	struct usb_serial *serial = port->serial;
516 	unsigned long flags;
517 	int result = 0;
518 
519 	dbg("%s - port %d", __FUNCTION__, port->number);
520 
521 	/* clear halts before open */
522 	usb_clear_halt(serial->dev, 0x81);
523 	usb_clear_halt(serial->dev, 0x02);
524 
525 	spin_lock_irqsave(&priv->lock, flags);
526 	/* reset read/write statistics */
527 	priv->bytes_in = 0;
528 	priv->bytes_out = 0;
529 	priv->cmd_count = 0;
530 	priv->rx_flags = 0;
531 	spin_unlock_irqrestore(&priv->lock, flags);
532 
533 	/* setting to zero could cause data loss */
534 	port->tty->low_latency = 1;
535 
536 	/* raise both lines and set termios */
537 	spin_lock_irqsave(&priv->lock, flags);
538 	priv->line_control = CONTROL_DTR | CONTROL_RTS;
539 	priv->cmd_ctrl = 1;
540 	spin_unlock_irqrestore(&priv->lock, flags);
541 	result = cypress_write(port, NULL, 0);
542 
543 	if (result) {
544 		dev_err(&port->dev, "%s - failed setting the control lines - error %d\n", __FUNCTION__, result);
545 		return result;
546 	} else
547 		dbg("%s - success setting the control lines", __FUNCTION__);
548 
549 	cypress_set_termios(port, &priv->tmp_termios);
550 
551 	/* setup the port and start reading from the device */
552 	if(!port->interrupt_in_urb){
553 		err("%s - interrupt_in_urb is empty!", __FUNCTION__);
554 		return(-1);
555 	}
556 
557 	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
558 		usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
559 		port->interrupt_in_urb->transfer_buffer, port->interrupt_in_urb->transfer_buffer_length,
560 		cypress_read_int_callback, port, interval);
561 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
562 
563 	if (result){
564 		dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
565 	}
566 
567 	return result;
568 } /* cypress_open */
569 
570 
571 static void cypress_close(struct usb_serial_port *port, struct file * filp)
572 {
573 	struct cypress_private *priv = usb_get_serial_port_data(port);
574 	unsigned int c_cflag;
575 	unsigned long flags;
576 	int bps;
577 	long timeout;
578 	wait_queue_t wait;
579 
580 	dbg("%s - port %d", __FUNCTION__, port->number);
581 
582 	/* wait for data to drain from buffer */
583 	spin_lock_irqsave(&priv->lock, flags);
584 	timeout = CYPRESS_CLOSING_WAIT;
585 	init_waitqueue_entry(&wait, current);
586 	add_wait_queue(&port->tty->write_wait, &wait);
587 	for (;;) {
588 		set_current_state(TASK_INTERRUPTIBLE);
589 		if (cypress_buf_data_avail(priv->buf) == 0
590 		|| timeout == 0 || signal_pending(current)
591 		|| !usb_get_intfdata(port->serial->interface))
592 			break;
593 		spin_unlock_irqrestore(&priv->lock, flags);
594 		timeout = schedule_timeout(timeout);
595 		spin_lock_irqsave(&priv->lock, flags);
596 	}
597 	set_current_state(TASK_RUNNING);
598 	remove_wait_queue(&port->tty->write_wait, &wait);
599 	/* clear out any remaining data in the buffer */
600 	cypress_buf_clear(priv->buf);
601 	spin_unlock_irqrestore(&priv->lock, flags);
602 
603 	/* wait for characters to drain from device */
604 	bps = tty_get_baud_rate(port->tty);
605 	if (bps > 1200)
606 		timeout = max((HZ*2560)/bps,HZ/10);
607 	else
608 		timeout = 2*HZ;
609 	set_current_state(TASK_INTERRUPTIBLE);
610 	schedule_timeout(timeout);
611 
612 	dbg("%s - stopping urbs", __FUNCTION__);
613 	usb_kill_urb (port->interrupt_in_urb);
614 	usb_kill_urb (port->interrupt_out_urb);
615 
616 	if (port->tty) {
617 		c_cflag = port->tty->termios->c_cflag;
618 		if (c_cflag & HUPCL) {
619 			/* drop dtr and rts */
620 			priv = usb_get_serial_port_data(port);
621 			spin_lock_irqsave(&priv->lock, flags);
622 			priv->line_control = 0;
623 			priv->cmd_ctrl = 1;
624 			spin_unlock_irqrestore(&priv->lock, flags);
625 			cypress_write(port, NULL, 0);
626 		}
627 	}
628 
629 	if (stats)
630 		dev_info (&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
631 		          priv->bytes_in, priv->bytes_out, priv->cmd_count);
632 } /* cypress_close */
633 
634 
635 static int cypress_write(struct usb_serial_port *port, const unsigned char *buf, int count)
636 {
637 	struct cypress_private *priv = usb_get_serial_port_data(port);
638 	unsigned long flags;
639 
640 	dbg("%s - port %d, %d bytes", __FUNCTION__, port->number, count);
641 
642 	/* line control commands, which need to be executed immediately,
643 	   are not put into the buffer for obvious reasons.
644 	 */
645 	if (priv->cmd_ctrl) {
646 		count = 0;
647 		goto finish;
648 	}
649 
650 	if (!count)
651 		return count;
652 
653 	spin_lock_irqsave(&priv->lock, flags);
654 	count = cypress_buf_put(priv->buf, buf, count);
655 	spin_unlock_irqrestore(&priv->lock, flags);
656 
657 finish:
658 	cypress_send(port);
659 
660 	return count;
661 } /* cypress_write */
662 
663 
664 static void cypress_send(struct usb_serial_port *port)
665 {
666 	int count = 0, result, offset, actual_size;
667 	struct cypress_private *priv = usb_get_serial_port_data(port);
668 	unsigned long flags;
669 
670 	dbg("%s - port %d", __FUNCTION__, port->number);
671 	dbg("%s - interrupt out size is %d", __FUNCTION__, port->interrupt_out_size);
672 
673 	spin_lock_irqsave(&priv->lock, flags);
674 	if (priv->write_urb_in_use) {
675 		dbg("%s - can't write, urb in use", __FUNCTION__);
676 		spin_unlock_irqrestore(&priv->lock, flags);
677 		return;
678 	}
679 	spin_unlock_irqrestore(&priv->lock, flags);
680 
681 	/* clear buffer */
682 	memset(port->interrupt_out_urb->transfer_buffer, 0, port->interrupt_out_size);
683 
684 	spin_lock_irqsave(&priv->lock, flags);
685 	switch (port->interrupt_out_size) {
686 		case 32:
687 			/* this is for the CY7C64013... */
688 			offset = 2;
689 			port->interrupt_out_buffer[0] = priv->line_control;
690 			break;
691 		case 8:
692 			/* this is for the CY7C63743... */
693 			offset = 1;
694 			port->interrupt_out_buffer[0] = priv->line_control;
695 			break;
696 		default:
697 			dbg("%s - wrong packet size", __FUNCTION__);
698 			spin_unlock_irqrestore(&priv->lock, flags);
699 			return;
700 	}
701 
702 	if (priv->line_control & CONTROL_RESET)
703 		priv->line_control &= ~CONTROL_RESET;
704 
705 	if (priv->cmd_ctrl) {
706 		priv->cmd_count++;
707 		dbg("%s - line control command being issued", __FUNCTION__);
708 		spin_unlock_irqrestore(&priv->lock, flags);
709 		goto send;
710 	} else
711 		spin_unlock_irqrestore(&priv->lock, flags);
712 
713 	count = cypress_buf_get(priv->buf, &port->interrupt_out_buffer[offset],
714 				port->interrupt_out_size-offset);
715 
716 	if (count == 0) {
717 		return;
718 	}
719 
720 	switch (port->interrupt_out_size) {
721 		case 32:
722 			port->interrupt_out_buffer[1] = count;
723 			break;
724 		case 8:
725 			port->interrupt_out_buffer[0] |= count;
726 	}
727 
728 	dbg("%s - count is %d", __FUNCTION__, count);
729 
730 send:
731 	spin_lock_irqsave(&priv->lock, flags);
732 	priv->write_urb_in_use = 1;
733 	spin_unlock_irqrestore(&priv->lock, flags);
734 
735 	if (priv->cmd_ctrl)
736 		actual_size = 1;
737 	else
738 		actual_size = count + (port->interrupt_out_size == 32 ? 2 : 1);
739 
740 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, port->interrupt_out_size,
741 			      port->interrupt_out_urb->transfer_buffer);
742 
743 	port->interrupt_out_urb->transfer_buffer_length = actual_size;
744 	port->interrupt_out_urb->dev = port->serial->dev;
745 	port->interrupt_out_urb->interval = interval;
746 	result = usb_submit_urb (port->interrupt_out_urb, GFP_ATOMIC);
747 	if (result) {
748 		dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__,
749 			result);
750 		priv->write_urb_in_use = 0;
751 	}
752 
753 	spin_lock_irqsave(&priv->lock, flags);
754 	if (priv->cmd_ctrl) {
755 		priv->cmd_ctrl = 0;
756 	}
757 	priv->bytes_out += count; /* do not count the line control and size bytes */
758 	spin_unlock_irqrestore(&priv->lock, flags);
759 
760 	schedule_work(&port->work);
761 } /* cypress_send */
762 
763 
764 /* returns how much space is available in the soft buffer */
765 static int cypress_write_room(struct usb_serial_port *port)
766 {
767 	struct cypress_private *priv = usb_get_serial_port_data(port);
768 	int room = 0;
769 	unsigned long flags;
770 
771 	dbg("%s - port %d", __FUNCTION__, port->number);
772 
773 	spin_lock_irqsave(&priv->lock, flags);
774 	room = cypress_buf_space_avail(priv->buf);
775 	spin_unlock_irqrestore(&priv->lock, flags);
776 
777 	dbg("%s - returns %d", __FUNCTION__, room);
778 	return room;
779 }
780 
781 
782 static int cypress_tiocmget (struct usb_serial_port *port, struct file *file)
783 {
784 	struct cypress_private *priv = usb_get_serial_port_data(port);
785 	__u8 status, control;
786 	unsigned int result = 0;
787 	unsigned long flags;
788 
789 	dbg("%s - port %d", __FUNCTION__, port->number);
790 
791 	spin_lock_irqsave(&priv->lock, flags);
792 	control = priv->line_control;
793 	status = priv->current_status;
794 	spin_unlock_irqrestore(&priv->lock, flags);
795 
796 	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
797 		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
798 		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
799 		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
800 		| ((status & UART_RI)         ? TIOCM_RI  : 0)
801 		| ((status & UART_CD)         ? TIOCM_CD  : 0);
802 
803 	dbg("%s - result = %x", __FUNCTION__, result);
804 
805 	return result;
806 }
807 
808 
809 static int cypress_tiocmset (struct usb_serial_port *port, struct file *file,
810 			       unsigned int set, unsigned int clear)
811 {
812 	struct cypress_private *priv = usb_get_serial_port_data(port);
813 	unsigned long flags;
814 
815 	dbg("%s - port %d", __FUNCTION__, port->number);
816 
817 	spin_lock_irqsave(&priv->lock, flags);
818 	if (set & TIOCM_RTS)
819 		priv->line_control |= CONTROL_RTS;
820 	if (set & TIOCM_DTR)
821 		priv->line_control |= CONTROL_DTR;
822 	if (clear & TIOCM_RTS)
823 		priv->line_control &= ~CONTROL_RTS;
824 	if (clear & TIOCM_DTR)
825 		priv->line_control &= ~CONTROL_DTR;
826 	spin_unlock_irqrestore(&priv->lock, flags);
827 
828 	priv->cmd_ctrl = 1;
829 	return cypress_write(port, NULL, 0);
830 }
831 
832 
833 static int cypress_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
834 {
835 	struct cypress_private *priv = usb_get_serial_port_data(port);
836 
837 	dbg("%s - port %d, cmd 0x%.4x", __FUNCTION__, port->number, cmd);
838 
839 	switch (cmd) {
840 		case TIOCGSERIAL:
841 			if (copy_to_user((void __user *)arg, port->tty->termios, sizeof(struct termios))) {
842 				return -EFAULT;
843 			}
844 			return (0);
845 			break;
846 		case TIOCSSERIAL:
847 			if (copy_from_user(port->tty->termios, (void __user *)arg, sizeof(struct termios))) {
848 				return -EFAULT;
849 			}
850 			/* here we need to call cypress_set_termios to invoke the new settings */
851 			cypress_set_termios(port, &priv->tmp_termios);
852 			return (0);
853 			break;
854 		/* these are called when setting baud rate from gpsd */
855 		case TCGETS:
856 			if (copy_to_user((void __user *)arg, port->tty->termios, sizeof(struct termios))) {
857 				return -EFAULT;
858 			}
859 			return (0);
860 			break;
861 		case TCSETS:
862 			if (copy_from_user(port->tty->termios, (void __user *)arg, sizeof(struct termios))) {
863 				return -EFAULT;
864 			}
865 			/* here we need to call cypress_set_termios to invoke the new settings */
866 			cypress_set_termios(port, &priv->tmp_termios);
867 			return (0);
868 			break;
869 		/* This code comes from drivers/char/serial.c and ftdi_sio.c */
870 		case TIOCMIWAIT:
871 			while (priv != NULL) {
872 				interruptible_sleep_on(&priv->delta_msr_wait);
873 				/* see if a signal did it */
874 				if (signal_pending(current))
875 					return -ERESTARTSYS;
876 				else {
877 					char diff = priv->diff_status;
878 
879 					if (diff == 0) {
880 						return -EIO; /* no change => error */
881 					}
882 
883 					/* consume all events */
884 					priv->diff_status = 0;
885 
886 					/* return 0 if caller wanted to know about these bits */
887 					if ( ((arg & TIOCM_RNG) && (diff & UART_RI)) ||
888 					     ((arg & TIOCM_DSR) && (diff & UART_DSR)) ||
889 					     ((arg & TIOCM_CD) && (diff & UART_CD)) ||
890 					     ((arg & TIOCM_CTS) && (diff & UART_CTS)) ) {
891 						return 0;
892 					}
893 					/* otherwise caller can't care less about what happened,
894 					 * and so we continue to wait for more events.
895 					 */
896 				}
897 			}
898 			return 0;
899 			break;
900 		default:
901 			break;
902 	}
903 
904 	dbg("%s - arg not supported - it was 0x%04x - check include/asm/ioctls.h", __FUNCTION__, cmd);
905 
906 	return -ENOIOCTLCMD;
907 } /* cypress_ioctl */
908 
909 
910 static void cypress_set_termios (struct usb_serial_port *port, struct termios *old_termios)
911 {
912 	struct cypress_private *priv = usb_get_serial_port_data(port);
913 	struct tty_struct *tty;
914 	int data_bits, stop_bits, parity_type, parity_enable;
915 	unsigned cflag, iflag, baud_mask;
916 	unsigned long flags;
917 	__u8 oldlines;
918 	int linechange = 0;
919 
920 	dbg("%s - port %d", __FUNCTION__, port->number);
921 
922 	tty = port->tty;
923 	if ((!tty) || (!tty->termios)) {
924 		dbg("%s - no tty structures", __FUNCTION__);
925 		return;
926 	}
927 
928 	spin_lock_irqsave(&priv->lock, flags);
929 	if (!priv->termios_initialized) {
930 		if (priv->chiptype == CT_EARTHMATE) {
931 			*(tty->termios) = tty_std_termios;
932 			tty->termios->c_cflag = B4800 | CS8 | CREAD | HUPCL | CLOCAL;
933 		} else if (priv->chiptype == CT_CYPHIDCOM) {
934 			*(tty->termios) = tty_std_termios;
935 			tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
936 		}
937 		priv->termios_initialized = 1;
938 	}
939 	spin_unlock_irqrestore(&priv->lock, flags);
940 
941 	cflag = tty->termios->c_cflag;
942 	iflag = tty->termios->c_iflag;
943 
944 	/* check if there are new settings */
945 	if (old_termios) {
946 		if ((cflag != old_termios->c_cflag) ||
947 		    (RELEVANT_IFLAG(iflag) != RELEVANT_IFLAG(old_termios->c_iflag))) {
948 			dbg("%s - attempting to set new termios settings", __FUNCTION__);
949 			/* should make a copy of this in case something goes wrong in the function, we can restore it */
950 			spin_lock_irqsave(&priv->lock, flags);
951 			priv->tmp_termios = *(tty->termios);
952 			spin_unlock_irqrestore(&priv->lock, flags);
953 		} else {
954 			dbg("%s - nothing to do, exiting", __FUNCTION__);
955 			return;
956 		}
957 	} else
958 		return;
959 
960 	/* set number of data bits, parity, stop bits */
961 	/* when parity is disabled the parity type bit is ignored */
962 
963 	stop_bits = cflag & CSTOPB ? 1 : 0; /* 1 means 2 stop bits, 0 means 1 stop bit */
964 
965 	if (cflag & PARENB) {
966 		parity_enable = 1;
967 		parity_type = cflag & PARODD ? 1 : 0; /* 1 means odd parity, 0 means even parity */
968 	} else
969 		parity_enable = parity_type = 0;
970 
971 	if (cflag & CSIZE) {
972 		switch (cflag & CSIZE) {
973 			case CS5: data_bits = 0; break;
974 			case CS6: data_bits = 1; break;
975 			case CS7: data_bits = 2; break;
976 			case CS8: data_bits = 3; break;
977 			default: err("%s - CSIZE was set, but not CS5-CS8", __FUNCTION__); data_bits = 3;
978 		}
979 	} else
980 		data_bits = 3;
981 
982 	spin_lock_irqsave(&priv->lock, flags);
983 	oldlines = priv->line_control;
984 	if ((cflag & CBAUD) == B0) {
985 		/* drop dtr and rts */
986 		dbg("%s - dropping the lines, baud rate 0bps", __FUNCTION__);
987 		baud_mask = B0;
988 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
989 	} else {
990 		baud_mask = (cflag & CBAUD);
991 		switch(baud_mask) {
992 			case B300: dbg("%s - setting baud 300bps", __FUNCTION__); break;
993 			case B600: dbg("%s - setting baud 600bps", __FUNCTION__); break;
994 			case B1200: dbg("%s - setting baud 1200bps", __FUNCTION__); break;
995 			case B2400: dbg("%s - setting baud 2400bps", __FUNCTION__); break;
996 			case B4800: dbg("%s - setting baud 4800bps", __FUNCTION__); break;
997 			case B9600: dbg("%s - setting baud 9600bps", __FUNCTION__); break;
998 			case B19200: dbg("%s - setting baud 19200bps", __FUNCTION__); break;
999 			case B38400: dbg("%s - setting baud 38400bps", __FUNCTION__); break;
1000 			case B57600: dbg("%s - setting baud 57600bps", __FUNCTION__); break;
1001 			case B115200: dbg("%s - setting baud 115200bps", __FUNCTION__); break;
1002 			default: dbg("%s - unknown masked baud rate", __FUNCTION__);
1003 		}
1004 		priv->line_control = (CONTROL_DTR | CONTROL_RTS);
1005 	}
1006 	spin_unlock_irqrestore(&priv->lock, flags);
1007 
1008 	dbg("%s - sending %d stop_bits, %d parity_enable, %d parity_type, %d data_bits (+5)", __FUNCTION__,
1009 	    stop_bits, parity_enable, parity_type, data_bits);
1010 
1011 	cypress_serial_control(port, baud_mask, data_bits, stop_bits, parity_enable,
1012 			       parity_type, 0, CYPRESS_SET_CONFIG);
1013 
1014 	/* we perform a CYPRESS_GET_CONFIG so that the current settings are filled into the private structure
1015          * this should confirm that all is working if it returns what we just set */
1016 	cypress_serial_control(port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
1017 
1018 	/* Here we can define custom tty settings for devices
1019          *
1020          * the main tty termios flag base comes from empeg.c
1021          */
1022 
1023 	spin_lock_irqsave(&priv->lock, flags);
1024 	if ( (priv->chiptype == CT_EARTHMATE) && (priv->baud_rate == 4800) ) {
1025 
1026 		dbg("Using custom termios settings for a baud rate of 4800bps.");
1027 		/* define custom termios settings for NMEA protocol */
1028 
1029 		tty->termios->c_iflag /* input modes - */
1030 			&= ~(IGNBRK		/* disable ignore break */
1031 			| BRKINT		/* disable break causes interrupt */
1032 			| PARMRK		/* disable mark parity errors */
1033 			| ISTRIP		/* disable clear high bit of input characters */
1034 			| INLCR			/* disable translate NL to CR */
1035 			| IGNCR			/* disable ignore CR */
1036 			| ICRNL			/* disable translate CR to NL */
1037 			| IXON);		/* disable enable XON/XOFF flow control */
1038 
1039 		tty->termios->c_oflag /* output modes */
1040 			&= ~OPOST;		/* disable postprocess output characters */
1041 
1042 		tty->termios->c_lflag /* line discipline modes */
1043 			&= ~(ECHO 		/* disable echo input characters */
1044 			| ECHONL		/* disable echo new line */
1045 			| ICANON		/* disable erase, kill, werase, and rprnt special characters */
1046 			| ISIG			/* disable interrupt, quit, and suspend special characters */
1047 			| IEXTEN);		/* disable non-POSIX special characters */
1048 
1049 	} /* CT_CYPHIDCOM: Application should handle this for device */
1050 
1051 	linechange = (priv->line_control != oldlines);
1052 	spin_unlock_irqrestore(&priv->lock, flags);
1053 
1054 	/* if necessary, set lines */
1055 	if (linechange) {
1056 		priv->cmd_ctrl = 1;
1057 		cypress_write(port, NULL, 0);
1058 	}
1059 } /* cypress_set_termios */
1060 
1061 
1062 /* returns amount of data still left in soft buffer */
1063 static int cypress_chars_in_buffer(struct usb_serial_port *port)
1064 {
1065 	struct cypress_private *priv = usb_get_serial_port_data(port);
1066 	int chars = 0;
1067 	unsigned long flags;
1068 
1069 	dbg("%s - port %d", __FUNCTION__, port->number);
1070 
1071 	spin_lock_irqsave(&priv->lock, flags);
1072 	chars = cypress_buf_data_avail(priv->buf);
1073 	spin_unlock_irqrestore(&priv->lock, flags);
1074 
1075 	dbg("%s - returns %d", __FUNCTION__, chars);
1076 	return chars;
1077 }
1078 
1079 
1080 static void cypress_throttle (struct usb_serial_port *port)
1081 {
1082 	struct cypress_private *priv = usb_get_serial_port_data(port);
1083 	unsigned long flags;
1084 
1085 	dbg("%s - port %d", __FUNCTION__, port->number);
1086 
1087 	spin_lock_irqsave(&priv->lock, flags);
1088 	priv->rx_flags = THROTTLED;
1089 	spin_unlock_irqrestore(&priv->lock, flags);
1090 }
1091 
1092 
1093 static void cypress_unthrottle (struct usb_serial_port *port)
1094 {
1095 	struct cypress_private *priv = usb_get_serial_port_data(port);
1096 	int actually_throttled, result;
1097 	unsigned long flags;
1098 
1099 	dbg("%s - port %d", __FUNCTION__, port->number);
1100 
1101 	spin_lock_irqsave(&priv->lock, flags);
1102 	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
1103 	priv->rx_flags = 0;
1104 	spin_unlock_irqrestore(&priv->lock, flags);
1105 
1106 	if (actually_throttled) {
1107 		port->interrupt_in_urb->dev = port->serial->dev;
1108 
1109 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1110 		if (result)
1111 			dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
1112 	}
1113 }
1114 
1115 
1116 static void cypress_read_int_callback(struct urb *urb, struct pt_regs *regs)
1117 {
1118 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
1119 	struct cypress_private *priv = usb_get_serial_port_data(port);
1120 	struct tty_struct *tty;
1121 	unsigned char *data = urb->transfer_buffer;
1122 	unsigned long flags;
1123 	char tty_flag = TTY_NORMAL;
1124 	int havedata = 0;
1125 	int bytes = 0;
1126 	int result;
1127 	int i = 0;
1128 
1129 	dbg("%s - port %d", __FUNCTION__, port->number);
1130 
1131 	if (urb->status) {
1132 		dbg("%s - nonzero read status received: %d", __FUNCTION__, urb->status);
1133 		return;
1134 	}
1135 
1136 	spin_lock_irqsave(&priv->lock, flags);
1137 	if (priv->rx_flags & THROTTLED) {
1138 		dbg("%s - now throttling", __FUNCTION__);
1139 		priv->rx_flags |= ACTUALLY_THROTTLED;
1140 		spin_unlock_irqrestore(&priv->lock, flags);
1141 		return;
1142 	}
1143 	spin_unlock_irqrestore(&priv->lock, flags);
1144 
1145 	tty = port->tty;
1146 	if (!tty) {
1147 		dbg("%s - bad tty pointer - exiting", __FUNCTION__);
1148 		return;
1149 	}
1150 
1151 	spin_lock_irqsave(&priv->lock, flags);
1152 	switch(urb->actual_length) {
1153 		case 32:
1154 			/* This is for the CY7C64013... */
1155 			priv->current_status = data[0] & 0xF8;
1156 			bytes = data[1]+2;
1157 			i=2;
1158 			if (bytes > 2)
1159 				havedata = 1;
1160 			break;
1161 		case 8:
1162 			/* This is for the CY7C63743... */
1163 			priv->current_status = data[0] & 0xF8;
1164 			bytes = (data[0] & 0x07)+1;
1165 			i=1;
1166 			if (bytes > 1)
1167 				havedata = 1;
1168 			break;
1169 		default:
1170 			dbg("%s - wrong packet size - received %d bytes", __FUNCTION__, urb->actual_length);
1171 			spin_unlock_irqrestore(&priv->lock, flags);
1172 			goto continue_read;
1173 	}
1174 	spin_unlock_irqrestore(&priv->lock, flags);
1175 
1176 	usb_serial_debug_data (debug, &port->dev, __FUNCTION__, urb->actual_length, data);
1177 
1178 	spin_lock_irqsave(&priv->lock, flags);
1179 	/* check to see if status has changed */
1180 	if (priv != NULL) {
1181 		if (priv->current_status != priv->prev_status) {
1182 			priv->diff_status |= priv->current_status ^ priv->prev_status;
1183 			wake_up_interruptible(&priv->delta_msr_wait);
1184 			priv->prev_status = priv->current_status;
1185 		}
1186 	}
1187 	spin_unlock_irqrestore(&priv->lock, flags);
1188 
1189 	/* hangup, as defined in acm.c... this might be a bad place for it though */
1190 	if (tty && !(tty->termios->c_cflag & CLOCAL) && !(priv->current_status & UART_CD)) {
1191 		dbg("%s - calling hangup", __FUNCTION__);
1192 		tty_hangup(tty);
1193 		goto continue_read;
1194 	}
1195 
1196 	/* There is one error bit... I'm assuming it is a parity error indicator
1197 	 * as the generic firmware will set this bit to 1 if a parity error occurs.
1198 	 * I can not find reference to any other error events.
1199 	 *
1200 	 */
1201 	spin_lock_irqsave(&priv->lock, flags);
1202 	if (priv->current_status & CYP_ERROR) {
1203 		spin_unlock_irqrestore(&priv->lock, flags);
1204 		tty_flag = TTY_PARITY;
1205 		dbg("%s - Parity Error detected", __FUNCTION__);
1206 	} else
1207 		spin_unlock_irqrestore(&priv->lock, flags);
1208 
1209 	/* process read if there is data other than line status */
1210 	if (tty && (bytes > i)) {
1211 		for (; i < bytes ; ++i) {
1212 			dbg("pushing byte number %d - %d - %c",i,data[i],data[i]);
1213 			if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
1214 				tty_flip_buffer_push(tty);
1215 			}
1216 			tty_insert_flip_char(tty, data[i], tty_flag);
1217 		}
1218 		tty_flip_buffer_push(port->tty);
1219 	}
1220 
1221 	spin_lock_irqsave(&priv->lock, flags);
1222 	priv->bytes_in += bytes;  /* control and status byte(s) are also counted */
1223 	spin_unlock_irqrestore(&priv->lock, flags);
1224 
1225 continue_read:
1226 
1227 	/* Continue trying to always read... unless the port has closed.  */
1228 
1229 	if (port->open_count > 0) {
1230 	usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1231 		usb_rcvintpipe(port->serial->dev, port->interrupt_in_endpointAddress),
1232 		port->interrupt_in_urb->transfer_buffer,
1233 		port->interrupt_in_urb->transfer_buffer_length,
1234 		cypress_read_int_callback, port,
1235 		interval);
1236 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1237 	if (result)
1238 		dev_err(&urb->dev->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
1239 	}
1240 
1241 	return;
1242 } /* cypress_read_int_callback */
1243 
1244 
1245 static void cypress_write_int_callback(struct urb *urb, struct pt_regs *regs)
1246 {
1247 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
1248 	struct cypress_private *priv = usb_get_serial_port_data(port);
1249 	int result;
1250 
1251 	dbg("%s - port %d", __FUNCTION__, port->number);
1252 
1253 	switch (urb->status) {
1254 		case 0:
1255 			/* success */
1256 			break;
1257 		case -ECONNRESET:
1258 		case -ENOENT:
1259 		case -ESHUTDOWN:
1260 			/* this urb is terminated, clean up */
1261 			dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
1262 			priv->write_urb_in_use = 0;
1263 			return;
1264 		case -EPIPE: /* no break needed */
1265 			usb_clear_halt(port->serial->dev, 0x02);
1266 		default:
1267 			/* error in the urb, so we have to resubmit it */
1268 			dbg("%s - Overflow in write", __FUNCTION__);
1269 			dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
1270 			port->interrupt_out_urb->transfer_buffer_length = 1;
1271 			port->interrupt_out_urb->dev = port->serial->dev;
1272 			result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
1273 			if (result)
1274 				dev_err(&urb->dev->dev, "%s - failed resubmitting write urb, error %d\n",
1275 					__FUNCTION__, result);
1276 			else
1277 				return;
1278 	}
1279 
1280 	priv->write_urb_in_use = 0;
1281 
1282 	/* send any buffered data */
1283 	cypress_send(port);
1284 }
1285 
1286 
1287 /*****************************************************************************
1288  * Write buffer functions - buffering code from pl2303 used
1289  *****************************************************************************/
1290 
1291 /*
1292  * cypress_buf_alloc
1293  *
1294  * Allocate a circular buffer and all associated memory.
1295  */
1296 
1297 static struct cypress_buf *cypress_buf_alloc(unsigned int size)
1298 {
1299 
1300 	struct cypress_buf *cb;
1301 
1302 
1303 	if (size == 0)
1304 		return NULL;
1305 
1306 	cb = (struct cypress_buf *)kmalloc(sizeof(struct cypress_buf), GFP_KERNEL);
1307 	if (cb == NULL)
1308 		return NULL;
1309 
1310 	cb->buf_buf = kmalloc(size, GFP_KERNEL);
1311 	if (cb->buf_buf == NULL) {
1312 		kfree(cb);
1313 		return NULL;
1314 	}
1315 
1316 	cb->buf_size = size;
1317 	cb->buf_get = cb->buf_put = cb->buf_buf;
1318 
1319 	return cb;
1320 
1321 }
1322 
1323 
1324 /*
1325  * cypress_buf_free
1326  *
1327  * Free the buffer and all associated memory.
1328  */
1329 
1330 static void cypress_buf_free(struct cypress_buf *cb)
1331 {
1332 	if (cb) {
1333 		kfree(cb->buf_buf);
1334 		kfree(cb);
1335 	}
1336 }
1337 
1338 
1339 /*
1340  * cypress_buf_clear
1341  *
1342  * Clear out all data in the circular buffer.
1343  */
1344 
1345 static void cypress_buf_clear(struct cypress_buf *cb)
1346 {
1347 	if (cb != NULL)
1348 		cb->buf_get = cb->buf_put;
1349 		/* equivalent to a get of all data available */
1350 }
1351 
1352 
1353 /*
1354  * cypress_buf_data_avail
1355  *
1356  * Return the number of bytes of data available in the circular
1357  * buffer.
1358  */
1359 
1360 static unsigned int cypress_buf_data_avail(struct cypress_buf *cb)
1361 {
1362 	if (cb != NULL)
1363 		return ((cb->buf_size + cb->buf_put - cb->buf_get) % cb->buf_size);
1364 	else
1365 		return 0;
1366 }
1367 
1368 
1369 /*
1370  * cypress_buf_space_avail
1371  *
1372  * Return the number of bytes of space available in the circular
1373  * buffer.
1374  */
1375 
1376 static unsigned int cypress_buf_space_avail(struct cypress_buf *cb)
1377 {
1378 	if (cb != NULL)
1379 		return ((cb->buf_size + cb->buf_get - cb->buf_put - 1) % cb->buf_size);
1380 	else
1381 		return 0;
1382 }
1383 
1384 
1385 /*
1386  * cypress_buf_put
1387  *
1388  * Copy data data from a user buffer and put it into the circular buffer.
1389  * Restrict to the amount of space available.
1390  *
1391  * Return the number of bytes copied.
1392  */
1393 
1394 static unsigned int cypress_buf_put(struct cypress_buf *cb, const char *buf,
1395 	unsigned int count)
1396 {
1397 
1398 	unsigned int len;
1399 
1400 
1401 	if (cb == NULL)
1402 		return 0;
1403 
1404 	len  = cypress_buf_space_avail(cb);
1405 	if (count > len)
1406 		count = len;
1407 
1408 	if (count == 0)
1409 		return 0;
1410 
1411 	len = cb->buf_buf + cb->buf_size - cb->buf_put;
1412 	if (count > len) {
1413 		memcpy(cb->buf_put, buf, len);
1414 		memcpy(cb->buf_buf, buf+len, count - len);
1415 		cb->buf_put = cb->buf_buf + count - len;
1416 	} else {
1417 		memcpy(cb->buf_put, buf, count);
1418 		if (count < len)
1419 			cb->buf_put += count;
1420 		else /* count == len */
1421 			cb->buf_put = cb->buf_buf;
1422 	}
1423 
1424 	return count;
1425 
1426 }
1427 
1428 
1429 /*
1430  * cypress_buf_get
1431  *
1432  * Get data from the circular buffer and copy to the given buffer.
1433  * Restrict to the amount of data available.
1434  *
1435  * Return the number of bytes copied.
1436  */
1437 
1438 static unsigned int cypress_buf_get(struct cypress_buf *cb, char *buf,
1439 	unsigned int count)
1440 {
1441 
1442 	unsigned int len;
1443 
1444 
1445 	if (cb == NULL)
1446 		return 0;
1447 
1448 	len = cypress_buf_data_avail(cb);
1449 	if (count > len)
1450 		count = len;
1451 
1452 	if (count == 0)
1453 		return 0;
1454 
1455 	len = cb->buf_buf + cb->buf_size - cb->buf_get;
1456 	if (count > len) {
1457 		memcpy(buf, cb->buf_get, len);
1458 		memcpy(buf+len, cb->buf_buf, count - len);
1459 		cb->buf_get = cb->buf_buf + count - len;
1460 	} else {
1461 		memcpy(buf, cb->buf_get, count);
1462 		if (count < len)
1463 			cb->buf_get += count;
1464 		else /* count == len */
1465 			cb->buf_get = cb->buf_buf;
1466 	}
1467 
1468 	return count;
1469 
1470 }
1471 
1472 /*****************************************************************************
1473  * Module functions
1474  *****************************************************************************/
1475 
1476 static int __init cypress_init(void)
1477 {
1478 	int retval;
1479 
1480 	dbg("%s", __FUNCTION__);
1481 
1482 	retval = usb_serial_register(&cypress_earthmate_device);
1483 	if (retval)
1484 		goto failed_em_register;
1485 	retval = usb_serial_register(&cypress_hidcom_device);
1486 	if (retval)
1487 		goto failed_hidcom_register;
1488 	retval = usb_register(&cypress_driver);
1489 	if (retval)
1490 		goto failed_usb_register;
1491 
1492 	info(DRIVER_DESC " " DRIVER_VERSION);
1493 	return 0;
1494 failed_usb_register:
1495 	usb_deregister(&cypress_driver);
1496 failed_hidcom_register:
1497 	usb_serial_deregister(&cypress_hidcom_device);
1498 failed_em_register:
1499 	usb_serial_deregister(&cypress_earthmate_device);
1500 
1501 	return retval;
1502 }
1503 
1504 
1505 static void __exit cypress_exit (void)
1506 {
1507 	dbg("%s", __FUNCTION__);
1508 
1509 	usb_deregister (&cypress_driver);
1510 	usb_serial_deregister (&cypress_earthmate_device);
1511 	usb_serial_deregister (&cypress_hidcom_device);
1512 }
1513 
1514 
1515 module_init(cypress_init);
1516 module_exit(cypress_exit);
1517 
1518 MODULE_AUTHOR( DRIVER_AUTHOR );
1519 MODULE_DESCRIPTION( DRIVER_DESC );
1520 MODULE_VERSION( DRIVER_VERSION );
1521 MODULE_LICENSE("GPL");
1522 
1523 module_param(debug, bool, S_IRUGO | S_IWUSR);
1524 MODULE_PARM_DESC(debug, "Debug enabled or not");
1525 module_param(stats, bool, S_IRUGO | S_IWUSR);
1526 MODULE_PARM_DESC(stats, "Enable statistics or not");
1527 module_param(interval, int, S_IRUGO | S_IWUSR);
1528 MODULE_PARM_DESC(interval, "Overrides interrupt interval");
1529