xref: /openbmc/linux/drivers/usb/serial/cypress_m8.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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  *
20  *  Lonnie Mendez <dignome@gmail.com>
21  *  12-15-2004
22  *	Incorporated write buffering from pl2303 driver.  Fixed bug with line
23  *	handling so both lines are raised in cypress_open. (was dropping rts)
24  *      Various code cleanups made as well along with other misc bug fixes.
25  *
26  *  Lonnie Mendez <dignome@gmail.com>
27  *  04-10-2004
28  *	Driver modified to support dynamic line settings.  Various improvments
29  *      and features.
30  *
31  *  Neil Whelchel
32  *  10-2003
33  *	Driver first released.
34  *
35  *
36  * Long Term TODO:
37  *	Improve transfer speeds - both read/write are somewhat slow
38  *   at this point.
39  *      Improve debugging.  Show modem line status with debug output and
40  *   implement filtering for certain data as a module parameter.
41  */
42 
43 /* Thanks to Neil Whelchel for writing the first cypress m8 implementation for linux. */
44 /* Thanks to cypress for providing references for the hid reports. */
45 /* Thanks to Jiang Zhang for providing links and for general help. */
46 /* Code originates and was built up from ftdi_sio, belkin, pl2303 and others. */
47 
48 
49 #include <linux/config.h>
50 #include <linux/kernel.h>
51 #include <linux/errno.h>
52 #include <linux/init.h>
53 #include <linux/slab.h>
54 #include <linux/tty.h>
55 #include <linux/tty_driver.h>
56 #include <linux/tty_flip.h>
57 #include <linux/module.h>
58 #include <linux/moduleparam.h>
59 #include <linux/spinlock.h>
60 #include <linux/usb.h>
61 #include <linux/serial.h>
62 #include <linux/delay.h>
63 #include <asm/uaccess.h>
64 
65 #include "usb-serial.h"
66 #include "cypress_m8.h"
67 
68 
69 #ifdef CONFIG_USB_SERIAL_DEBUG
70 	static int debug = 1;
71 #else
72 	static int debug;
73 #endif
74 static int stats;
75 
76 /*
77  * Version Information
78  */
79 #define DRIVER_VERSION "v1.08"
80 #define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
81 #define DRIVER_DESC "Cypress USB to Serial Driver"
82 
83 /* write buffer size defines */
84 #define CYPRESS_BUF_SIZE	1024
85 #define CYPRESS_CLOSING_WAIT	(30*HZ)
86 
87 static struct usb_device_id id_table_earthmate [] = {
88 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
89 	{ }						/* Terminating entry */
90 };
91 
92 static struct usb_device_id id_table_cyphidcomrs232 [] = {
93 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
94 	{ }						/* Terminating entry */
95 };
96 
97 static struct usb_device_id id_table_combined [] = {
98 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
99 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
100 	{ }						/* Terminating entry */
101 };
102 
103 MODULE_DEVICE_TABLE (usb, id_table_combined);
104 
105 static struct usb_driver cypress_driver = {
106 	.name =		"cypress",
107 	.probe =	usb_serial_probe,
108 	.disconnect =	usb_serial_disconnect,
109 	.id_table =	id_table_combined,
110 };
111 
112 struct cypress_private {
113 	spinlock_t lock;		   /* private lock */
114 	int chiptype;			   /* identifier of device, for quirks/etc */
115 	int bytes_in;			   /* used for statistics */
116 	int bytes_out;			   /* used for statistics */
117 	int cmd_count;			   /* used for statistics */
118 	int cmd_ctrl;			   /* always set this to 1 before issuing a command */
119 	struct cypress_buf *buf;	   /* write buffer */
120 	int write_urb_in_use;		   /* write urb in use indicator */
121 	int termios_initialized;
122 	__u8 line_control;	   	   /* holds dtr / rts value */
123 	__u8 current_status;	   	   /* received from last read - info on dsr,cts,cd,ri,etc */
124 	__u8 current_config;	   	   /* stores the current configuration byte */
125 	__u8 rx_flags;			   /* throttling - used from whiteheat/ftdi_sio */
126 	int baud_rate;			   /* stores current baud rate in integer form */
127 	int cbr_mask;			   /* stores current baud rate in masked form */
128 	int isthrottled;		   /* if throttled, discard reads */
129 	wait_queue_head_t delta_msr_wait;  /* used for TIOCMIWAIT */
130 	char prev_status, diff_status;	   /* used for TIOCMIWAIT */
131 	/* we pass a pointer to this as the arguement sent to cypress_set_termios old_termios */
132 	struct termios tmp_termios; 	   /* stores the old termios settings */
133 	char calledfromopen;		   /* used when issuing lines on open - fixes rts drop bug */
134 };
135 
136 /* write buffer structure */
137 struct cypress_buf {
138 	unsigned int	buf_size;
139 	char		*buf_buf;
140 	char		*buf_get;
141 	char		*buf_put;
142 };
143 
144 /* function prototypes for the Cypress USB to serial device */
145 static int  cypress_earthmate_startup	(struct usb_serial *serial);
146 static int  cypress_hidcom_startup	(struct usb_serial *serial);
147 static void cypress_shutdown		(struct usb_serial *serial);
148 static int  cypress_open		(struct usb_serial_port *port, struct file *filp);
149 static void cypress_close		(struct usb_serial_port *port, struct file *filp);
150 static int  cypress_write		(struct usb_serial_port *port, const unsigned char *buf, int count);
151 static void cypress_send		(struct usb_serial_port *port);
152 static int  cypress_write_room		(struct usb_serial_port *port);
153 static int  cypress_ioctl		(struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg);
154 static void cypress_set_termios		(struct usb_serial_port *port, struct termios * old);
155 static int  cypress_tiocmget		(struct usb_serial_port *port, struct file *file);
156 static int  cypress_tiocmset		(struct usb_serial_port *port, struct file *file, unsigned int set, unsigned int clear);
157 static int  cypress_chars_in_buffer	(struct usb_serial_port *port);
158 static void cypress_throttle		(struct usb_serial_port *port);
159 static void cypress_unthrottle		(struct usb_serial_port *port);
160 static void cypress_read_int_callback	(struct urb *urb, struct pt_regs *regs);
161 static void cypress_write_int_callback	(struct urb *urb, struct pt_regs *regs);
162 /* baud helper functions */
163 static int	 mask_to_rate		(unsigned mask);
164 static unsigned  rate_to_mask		(int rate);
165 /* write buffer functions */
166 static struct cypress_buf *cypress_buf_alloc(unsigned int size);
167 static void 		  cypress_buf_free(struct cypress_buf *cb);
168 static void		  cypress_buf_clear(struct cypress_buf *cb);
169 static unsigned int	  cypress_buf_data_avail(struct cypress_buf *cb);
170 static unsigned int	  cypress_buf_space_avail(struct cypress_buf *cb);
171 static unsigned int	  cypress_buf_put(struct cypress_buf *cb, const char *buf,
172 					  unsigned int count);
173 static unsigned int	  cypress_buf_get(struct cypress_buf *cb, char *buf,
174 					  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 retreive 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 i, n_baud_rate = 0, retval = 0;
242 	struct cypress_private *priv;
243 	__u8 feature_buffer[5];
244 	__u8 config;
245 	unsigned long flags;
246 
247 	dbg("%s", __FUNCTION__);
248 
249 	priv = usb_get_serial_port_data(port);
250 
251 	switch(cypress_request_type) {
252 		case CYPRESS_SET_CONFIG:
253 
254 			/*
255 			 * The general purpose firmware for the Cypress M8 allows for a maximum speed
256  			 * of 57600bps (I have no idea whether DeLorme chose to use the general purpose
257 			 * firmware or not), if you need to modify this speed setting for your own
258 			 * project please add your own chiptype and modify the code likewise.  The
259 			 * Cypress HID->COM device will work successfully up to 115200bps.
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 (default to 4800)",
269 						    __FUNCTION__);
270 						n_baud_rate = 4800;
271 					} else if ( (n_baud_rate = mask_to_rate(baud_mask)) == -1) {
272 						err("%s - failed setting baud rate, unsupported speed (default to 4800)",
273 						    __FUNCTION__);
274 						n_baud_rate = 4800;
275 					}
276 				} else if (priv->chiptype == CT_CYPHIDCOM) {
277 					if ( (n_baud_rate = mask_to_rate(baud_mask)) == -1) {
278 						err("%s - failed setting baud rate, unsupported speed (default to 4800)",
279 						    __FUNCTION__);
280 						n_baud_rate = 4800;
281 					}
282 				} else if (priv->chiptype == CT_GENERIC) {
283 					if ( (n_baud_rate = mask_to_rate(baud_mask)) == -1) {
284 						err("%s - failed setting baud rate, unsupported speed (default to 4800)",
285 						    __FUNCTION__);
286 						n_baud_rate = 4800;
287 					}
288 				} else {
289 					info("%s - please define your chiptype, using 4800bps default", __FUNCTION__);
290 					n_baud_rate = 4800;
291 				}
292 			} else {  /* baud rate not changing, keep the old */
293 				n_baud_rate = priv->baud_rate;
294 			}
295 			dbg("%s - baud rate is being sent as %d", __FUNCTION__, n_baud_rate);
296 
297 
298 			/*
299 			 * This algorithm accredited to Jiang Jay Zhang... thanks for all the help!
300 			 */
301 			for (i = 0; i < 4; ++i) {
302 				feature_buffer[i] = ( n_baud_rate >> (i*8) & 0xFF );
303 			}
304 
305 			config = 0;	                 // reset config byte
306 			config |= data_bits;	         // assign data bits in 2 bit space ( max 3 )
307 			/* 1 bit gap */
308 			config |= (stop_bits << 3);      // assign stop bits in 1 bit space
309 			config |= (parity_enable << 4);  // assign parity flag in 1 bit space
310 			config |= (parity_type << 5); 	 // assign parity type in 1 bit space
311 			/* 1 bit gap */
312 			config |= (reset << 7);		 // assign reset at end of byte, 1 bit space
313 
314 			feature_buffer[4] = config;
315 
316 			dbg("%s - device is being sent this feature report:", __FUNCTION__);
317 			dbg("%s - %02X - %02X - %02X - %02X - %02X", __FUNCTION__, feature_buffer[0], feature_buffer[1],
318 		            feature_buffer[2], feature_buffer[3], feature_buffer[4]);
319 
320 			retval = usb_control_msg (port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
321 					  	  HID_REQ_SET_REPORT, USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
322 					  	  0x0300, 0, feature_buffer, 5, 500);
323 
324 			if (retval != 5)
325 				err("%s - failed sending serial line settings - %d", __FUNCTION__, retval);
326 			else {
327 				spin_lock_irqsave(&priv->lock, flags);
328 				priv->baud_rate = n_baud_rate;
329 				priv->cbr_mask = baud_mask;
330 				priv->current_config = config;
331 				++priv->cmd_count;
332 				spin_unlock_irqrestore(&priv->lock, flags);
333 			}
334 		break;
335 		case CYPRESS_GET_CONFIG:
336 			dbg("%s - retreiving serial line settings", __FUNCTION__);
337 			/* reset values in feature buffer */
338 			memset(feature_buffer, 0, 5);
339 
340 			retval = usb_control_msg (port->serial->dev, usb_rcvctrlpipe(port->serial->dev, 0),
341 						  HID_REQ_GET_REPORT, USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
342 						  0x0300, 0, feature_buffer, 5, 500);
343 			if (retval != 5) {
344 				err("%s - failed to retreive serial line settings - %d", __FUNCTION__, retval);
345 				return retval;
346 			} else {
347 				spin_lock_irqsave(&priv->lock, flags);
348 				/* store the config in one byte, and later use bit masks to check values */
349 				priv->current_config = feature_buffer[4];
350 				/* reverse the process above to get the baud_mask value */
351 				n_baud_rate = 0; // reset bits
352 				for (i = 0; i < 4; ++i) {
353 					n_baud_rate |= ( feature_buffer[i] << (i*8) );
354 				}
355 
356 				priv->baud_rate = n_baud_rate;
357 				if ( (priv->cbr_mask = rate_to_mask(n_baud_rate)) == 0x40)
358 					dbg("%s - failed setting the baud mask (not defined)", __FUNCTION__);
359 				++priv->cmd_count;
360 				spin_unlock_irqrestore(&priv->lock, flags);
361 			}
362 			break;
363 		default:
364 			err("%s - unsupported serial control command issued", __FUNCTION__);
365 	}
366 	return retval;
367 } /* cypress_serial_control */
368 
369 
370 /* given a baud mask, it will return speed on success */
371 static int mask_to_rate (unsigned mask)
372 {
373 	int rate;
374 
375 	switch (mask) {
376 		case B0: rate = 0; break;
377 		case B300: rate = 300; break;
378 		case B600: rate = 600; break;
379 		case B1200: rate = 1200; break;
380 		case B2400: rate = 2400; break;
381 		case B4800: rate = 4800; break;
382 		case B9600: rate = 9600; break;
383 		case B19200: rate = 19200; break;
384 		case B38400: rate = 38400; break;
385 		case B57600: rate = 57600; break;
386 		case B115200: rate = 115200; break;
387 		default: rate = -1;
388 	}
389 
390 	return rate;
391 }
392 
393 
394 static unsigned rate_to_mask (int rate)
395 {
396 	unsigned mask;
397 
398 	switch (rate) {
399 		case 0: mask = B0; break;
400 		case 300: mask = B300; break;
401 		case 600: mask = B600; break;
402 		case 1200: mask = B1200; break;
403 		case 2400: mask = B2400; break;
404 		case 4800: mask = B4800; break;
405 		case 9600: mask = B9600; break;
406 		case 19200: mask = B19200; break;
407 		case 38400: mask = B38400; break;
408 		case 57600: mask = B57600; break;
409 		case 115200: mask = B115200; break;
410 		default: mask = 0x40;
411 	}
412 
413 	return mask;
414 }
415 /*****************************************************************************
416  * Cypress serial driver functions
417  *****************************************************************************/
418 
419 
420 static int generic_startup (struct usb_serial *serial)
421 {
422 	struct cypress_private *priv;
423 
424 	dbg("%s - port %d", __FUNCTION__, serial->port[0]->number);
425 
426 	priv = kmalloc(sizeof (struct cypress_private), GFP_KERNEL);
427 	if (!priv)
428 		return -ENOMEM;
429 
430 	memset(priv, 0x00, sizeof (struct cypress_private));
431 	spin_lock_init(&priv->lock);
432 	priv->buf = cypress_buf_alloc(CYPRESS_BUF_SIZE);
433 	if (priv->buf == NULL) {
434 		kfree(priv);
435 		return -ENOMEM;
436 	}
437 	init_waitqueue_head(&priv->delta_msr_wait);
438 
439 	usb_reset_configuration (serial->dev);
440 
441 	priv->cmd_ctrl = 0;
442 	priv->line_control = 0;
443 	priv->termios_initialized = 0;
444 	priv->calledfromopen = 0;
445 	priv->rx_flags = 0;
446 	usb_set_serial_port_data(serial->port[0], priv);
447 
448 	return (0);
449 }
450 
451 
452 static int cypress_earthmate_startup (struct usb_serial *serial)
453 {
454 	struct cypress_private *priv;
455 
456 	dbg("%s", __FUNCTION__);
457 
458 	if (generic_startup(serial)) {
459 		dbg("%s - Failed setting up port %d", __FUNCTION__, serial->port[0]->number);
460 		return 1;
461 	}
462 
463 	priv = usb_get_serial_port_data(serial->port[0]);
464 	priv->chiptype = CT_EARTHMATE;
465 
466 	return (0);
467 } /* cypress_earthmate_startup */
468 
469 
470 static int cypress_hidcom_startup (struct usb_serial *serial)
471 {
472 	struct cypress_private *priv;
473 
474 	dbg("%s", __FUNCTION__);
475 
476 	if (generic_startup(serial)) {
477 		dbg("%s - Failed setting up port %d", __FUNCTION__, serial->port[0]->number);
478 		return 1;
479 	}
480 
481 	priv = usb_get_serial_port_data(serial->port[0]);
482 	priv->chiptype = CT_CYPHIDCOM;
483 
484 	return (0);
485 } /* cypress_hidcom_startup */
486 
487 
488 static void cypress_shutdown (struct usb_serial *serial)
489 {
490 	struct cypress_private *priv;
491 
492 	dbg ("%s - port %d", __FUNCTION__, serial->port[0]->number);
493 
494 	/* all open ports are closed at this point */
495 
496 	priv = usb_get_serial_port_data(serial->port[0]);
497 
498 	if (priv) {
499 		cypress_buf_free(priv->buf);
500 		kfree(priv);
501 		usb_set_serial_port_data(serial->port[0], NULL);
502 	}
503 }
504 
505 
506 static int cypress_open (struct usb_serial_port *port, struct file *filp)
507 {
508 	struct cypress_private *priv = usb_get_serial_port_data(port);
509 	struct usb_serial *serial = port->serial;
510 	unsigned long flags;
511 	int result = 0;
512 
513 	dbg("%s - port %d", __FUNCTION__, port->number);
514 
515 	/* clear halts before open */
516 	usb_clear_halt(serial->dev, 0x00);
517 	usb_clear_halt(serial->dev, 0x81);
518 	usb_clear_halt(serial->dev, 0x02);
519 
520 	spin_lock_irqsave(&priv->lock, flags);
521 	/* reset read/write statistics */
522 	priv->bytes_in = 0;
523 	priv->bytes_out = 0;
524 	priv->cmd_count = 0;
525 	priv->rx_flags = 0;
526 	spin_unlock_irqrestore(&priv->lock, flags);
527 
528 	/* setting to zero could cause data loss */
529 	port->tty->low_latency = 1;
530 
531 	/* raise both lines and set termios */
532 	spin_lock_irqsave(&priv->lock, flags);
533 	priv->line_control = CONTROL_DTR | CONTROL_RTS;
534 	priv->calledfromopen = 1;
535 	priv->cmd_ctrl = 1;
536 	spin_unlock_irqrestore(&priv->lock, flags);
537 	result = cypress_write(port, NULL, 0);
538 
539 	if (result) {
540 		dev_err(&port->dev, "%s - failed setting the control lines - error %d\n", __FUNCTION__, result);
541 		return result;
542 	} else
543 		dbg("%s - success setting the control lines", __FUNCTION__);
544 
545 	cypress_set_termios(port, &priv->tmp_termios);
546 
547 	/* setup the port and start reading from the device */
548 	if(!port->interrupt_in_urb){
549 		err("%s - interrupt_in_urb is empty!", __FUNCTION__);
550 		return(-1);
551 	}
552 
553 	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
554 		usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
555 		port->interrupt_in_urb->transfer_buffer, port->interrupt_in_urb->transfer_buffer_length,
556 		cypress_read_int_callback, port, port->interrupt_in_urb->interval);
557 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
558 
559 	if (result){
560 		dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
561 	}
562 
563 	return result;
564 } /* cypress_open */
565 
566 
567 static void cypress_close(struct usb_serial_port *port, struct file * filp)
568 {
569 	struct cypress_private *priv = usb_get_serial_port_data(port);
570 	unsigned int c_cflag;
571 	unsigned long flags;
572 	int bps;
573 	long timeout;
574 	wait_queue_t wait;
575 
576 	dbg("%s - port %d", __FUNCTION__, port->number);
577 
578 	/* wait for data to drain from buffer */
579 	spin_lock_irqsave(&priv->lock, flags);
580 	timeout = CYPRESS_CLOSING_WAIT;
581 	init_waitqueue_entry(&wait, current);
582 	add_wait_queue(&port->tty->write_wait, &wait);
583 	for (;;) {
584 		set_current_state(TASK_INTERRUPTIBLE);
585 		if (cypress_buf_data_avail(priv->buf) == 0
586 		|| timeout == 0 || signal_pending(current)
587 		|| !usb_get_intfdata(port->serial->interface))
588 			break;
589 		spin_unlock_irqrestore(&priv->lock, flags);
590 		timeout = schedule_timeout(timeout);
591 		spin_lock_irqsave(&priv->lock, flags);
592 	}
593 	set_current_state(TASK_RUNNING);
594 	remove_wait_queue(&port->tty->write_wait, &wait);
595 	/* clear out any remaining data in the buffer */
596 	cypress_buf_clear(priv->buf);
597 	spin_unlock_irqrestore(&priv->lock, flags);
598 
599 	/* wait for characters to drain from device */
600 	bps = tty_get_baud_rate(port->tty);
601 	if (bps > 1200)
602 		timeout = max((HZ*2560)/bps,HZ/10);
603 	else
604 		timeout = 2*HZ;
605 	set_current_state(TASK_INTERRUPTIBLE);
606 	schedule_timeout(timeout);
607 
608 	dbg("%s - stopping urbs", __FUNCTION__);
609 	usb_kill_urb (port->interrupt_in_urb);
610 	usb_kill_urb (port->interrupt_out_urb);
611 
612 	if (port->tty) {
613 		c_cflag = port->tty->termios->c_cflag;
614 		if (c_cflag & HUPCL) {
615 			/* drop dtr and rts */
616 			priv = usb_get_serial_port_data(port);
617 			spin_lock_irqsave(&priv->lock, flags);
618 			priv->line_control = 0;
619 			priv->cmd_ctrl = 1;
620 			spin_unlock_irqrestore(&priv->lock, flags);
621 			cypress_write(port, NULL, 0);
622 		}
623 	}
624 
625 	if (stats)
626 		dev_info (&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
627 		          priv->bytes_in, priv->bytes_out, priv->cmd_count);
628 } /* cypress_close */
629 
630 
631 static int cypress_write(struct usb_serial_port *port, const unsigned char *buf, int count)
632 {
633 	struct cypress_private *priv = usb_get_serial_port_data(port);
634 	unsigned long flags;
635 
636 	dbg("%s - port %d, %d bytes", __FUNCTION__, port->number, count);
637 
638 	/* line control commands, which need to be executed immediately,
639 	   are not put into the buffer for obvious reasons.
640 	 */
641 	if (priv->cmd_ctrl) {
642 		count = 0;
643 		goto finish;
644 	}
645 
646 	if (!count)
647 		return count;
648 
649 	spin_lock_irqsave(&priv->lock, flags);
650 	count = cypress_buf_put(priv->buf, buf, count);
651 	spin_unlock_irqrestore(&priv->lock, flags);
652 
653 finish:
654 	cypress_send(port);
655 
656 	return count;
657 } /* cypress_write */
658 
659 
660 static void cypress_send(struct usb_serial_port *port)
661 {
662 	int count = 0, result, offset, actual_size;
663 	struct cypress_private *priv = usb_get_serial_port_data(port);
664 	unsigned long flags;
665 
666 	dbg("%s - port %d", __FUNCTION__, port->number);
667 	dbg("%s - interrupt out size is %d", __FUNCTION__, port->interrupt_out_size);
668 
669 	spin_lock_irqsave(&priv->lock, flags);
670 	if (priv->write_urb_in_use) {
671 		dbg("%s - can't write, urb in use", __FUNCTION__);
672 		spin_unlock_irqrestore(&priv->lock, flags);
673 		return;
674 	}
675 	spin_unlock_irqrestore(&priv->lock, flags);
676 
677 	/* clear buffer */
678 	memset(port->interrupt_out_urb->transfer_buffer, 0, port->interrupt_out_size);
679 
680 	spin_lock_irqsave(&priv->lock, flags);
681 	switch (port->interrupt_out_size) {
682 		case 32:
683 			// this is for the CY7C64013...
684 			offset = 2;
685 			port->interrupt_out_buffer[0] = priv->line_control;
686 			break;
687 		case 8:
688 			// this is for the CY7C63743...
689 			offset = 1;
690 			port->interrupt_out_buffer[0] = priv->line_control;
691 			break;
692 		default:
693 			dbg("%s - wrong packet size", __FUNCTION__);
694 			spin_unlock_irqrestore(&priv->lock, flags);
695 			return;
696 	}
697 
698 	if (priv->line_control & CONTROL_RESET)
699 		priv->line_control &= ~CONTROL_RESET;
700 
701 	if (priv->cmd_ctrl) {
702 		priv->cmd_count++;
703 		dbg("%s - line control command being issued", __FUNCTION__);
704 		spin_unlock_irqrestore(&priv->lock, flags);
705 		goto send;
706 	} else
707 		spin_unlock_irqrestore(&priv->lock, flags);
708 
709 	count = cypress_buf_get(priv->buf, &port->interrupt_out_buffer[offset],
710 				port->interrupt_out_size-offset);
711 
712 	if (count == 0) {
713 		return;
714 	}
715 
716 	switch (port->interrupt_out_size) {
717 		case 32:
718 			port->interrupt_out_buffer[1] = count;
719 			break;
720 		case 8:
721 			port->interrupt_out_buffer[0] |= count;
722 	}
723 
724 	dbg("%s - count is %d", __FUNCTION__, count);
725 
726 send:
727 	spin_lock_irqsave(&priv->lock, flags);
728 	priv->write_urb_in_use = 1;
729 	spin_unlock_irqrestore(&priv->lock, flags);
730 
731 	if (priv->cmd_ctrl)
732 		actual_size = 1;
733 	else
734 		actual_size = count + (port->interrupt_out_size == 32 ? 2 : 1);
735 
736 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, port->interrupt_out_size,
737 			      port->interrupt_out_urb->transfer_buffer);
738 
739 	port->interrupt_out_urb->transfer_buffer_length = actual_size;
740 	port->interrupt_out_urb->dev = port->serial->dev;
741 	result = usb_submit_urb (port->interrupt_out_urb, GFP_ATOMIC);
742 	if (result) {
743 		dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__,
744 			result);
745 		priv->write_urb_in_use = 0;
746 	}
747 
748 	spin_lock_irqsave(&priv->lock, flags);
749 	if (priv->cmd_ctrl) {
750 		priv->cmd_ctrl = 0;
751 	}
752 	priv->bytes_out += count; /* do not count the line control and size bytes */
753 	spin_unlock_irqrestore(&priv->lock, flags);
754 
755 	schedule_work(&port->work);
756 } /* cypress_send */
757 
758 
759 /* returns how much space is available in the soft buffer */
760 static int cypress_write_room(struct usb_serial_port *port)
761 {
762 	struct cypress_private *priv = usb_get_serial_port_data(port);
763 	int room = 0;
764 	unsigned long flags;
765 
766 	dbg("%s - port %d", __FUNCTION__, port->number);
767 
768 	spin_lock_irqsave(&priv->lock, flags);
769 	room = cypress_buf_space_avail(priv->buf);
770 	spin_unlock_irqrestore(&priv->lock, flags);
771 
772 	dbg("%s - returns %d", __FUNCTION__, room);
773 	return room;
774 }
775 
776 
777 static int cypress_tiocmget (struct usb_serial_port *port, struct file *file)
778 {
779 	struct cypress_private *priv = usb_get_serial_port_data(port);
780 	__u8 status, control;
781 	unsigned int result = 0;
782 	unsigned long flags;
783 
784 	dbg("%s - port %d", __FUNCTION__, port->number);
785 
786 	spin_lock_irqsave(&priv->lock, flags);
787 	control = priv->line_control;
788 	status = priv->current_status;
789 	spin_unlock_irqrestore(&priv->lock, flags);
790 
791 	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
792 		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
793 		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
794 		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
795 		| ((status & UART_RI)         ? TIOCM_RI  : 0)
796 		| ((status & UART_CD)         ? TIOCM_CD  : 0);
797 
798 	dbg("%s - result = %x", __FUNCTION__, result);
799 
800 	return result;
801 }
802 
803 
804 static int cypress_tiocmset (struct usb_serial_port *port, struct file *file,
805 			       unsigned int set, unsigned int clear)
806 {
807 	struct cypress_private *priv = usb_get_serial_port_data(port);
808 	unsigned long flags;
809 
810 	dbg("%s - port %d", __FUNCTION__, port->number);
811 
812 	spin_lock_irqsave(&priv->lock, flags);
813 	if (set & TIOCM_RTS)
814 		priv->line_control |= CONTROL_RTS;
815 	if (set & TIOCM_DTR)
816 		priv->line_control |= CONTROL_DTR;
817 	if (clear & TIOCM_RTS)
818 		priv->line_control &= ~CONTROL_RTS;
819 	if (clear & TIOCM_DTR)
820 		priv->line_control &= ~CONTROL_DTR;
821 	spin_unlock_irqrestore(&priv->lock, flags);
822 
823 	priv->cmd_ctrl = 1;
824 	return cypress_write(port, NULL, 0);
825 }
826 
827 
828 static int cypress_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
829 {
830 	struct cypress_private *priv = usb_get_serial_port_data(port);
831 
832 	dbg("%s - port %d, cmd 0x%.4x", __FUNCTION__, port->number, cmd);
833 
834 	switch (cmd) {
835 		case TIOCGSERIAL:
836 			if (copy_to_user((void __user *)arg, port->tty->termios, sizeof(struct termios))) {
837 				return -EFAULT;
838 			}
839 			return (0);
840 			break;
841 		case TIOCSSERIAL:
842 			if (copy_from_user(port->tty->termios, (void __user *)arg, sizeof(struct termios))) {
843 				return -EFAULT;
844 			}
845 			/* here we need to call cypress_set_termios to invoke the new settings */
846 			cypress_set_termios(port, &priv->tmp_termios);
847 			return (0);
848 			break;
849 		/* these are called when setting baud rate from gpsd */
850 		case TCGETS:
851 			if (copy_to_user((void __user *)arg, port->tty->termios, sizeof(struct termios))) {
852 				return -EFAULT;
853 			}
854 			return (0);
855 			break;
856 		case TCSETS:
857 			if (copy_from_user(port->tty->termios, (void __user *)arg, sizeof(struct termios))) {
858 				return -EFAULT;
859 			}
860 			/* here we need to call cypress_set_termios to invoke the new settings */
861 			cypress_set_termios(port, &priv->tmp_termios);
862 			return (0);
863 			break;
864 		/* This code comes from drivers/char/serial.c and ftdi_sio.c */
865 		case TIOCMIWAIT:
866 			while (priv != NULL) {
867 				interruptible_sleep_on(&priv->delta_msr_wait);
868 				/* see if a signal did it */
869 				if (signal_pending(current))
870 					return -ERESTARTSYS;
871 				else {
872 					char diff = priv->diff_status;
873 
874 					if (diff == 0) {
875 						return -EIO; /* no change => error */
876 					}
877 
878 					/* consume all events */
879 					priv->diff_status = 0;
880 
881 					/* return 0 if caller wanted to know about these bits */
882 					if ( ((arg & TIOCM_RNG) && (diff & UART_RI)) ||
883 					     ((arg & TIOCM_DSR) && (diff & UART_DSR)) ||
884 					     ((arg & TIOCM_CD) && (diff & UART_CD)) ||
885 					     ((arg & TIOCM_CTS) && (diff & UART_CTS)) ) {
886 						return 0;
887 					}
888 					/* otherwise caller can't care less about what happened,
889 					 * and so we continue to wait for more events.
890 					 */
891 				}
892 			}
893 			return 0;
894 			break;
895 		default:
896 			break;
897 	}
898 
899 	dbg("%s - arg not supported - it was 0x%04x - check include/asm/ioctls.h", __FUNCTION__, cmd);
900 
901 	return -ENOIOCTLCMD;
902 } /* cypress_ioctl */
903 
904 
905 static void cypress_set_termios (struct usb_serial_port *port, struct termios *old_termios)
906 {
907 	struct cypress_private *priv = usb_get_serial_port_data(port);
908 	struct tty_struct *tty;
909 	int data_bits, stop_bits, parity_type, parity_enable;
910 	unsigned cflag, iflag, baud_mask;
911 	unsigned long flags;
912 	__u8 oldlines;
913 	int linechange;
914 
915 	dbg("%s - port %d", __FUNCTION__, port->number);
916 
917 	tty = port->tty;
918 	if ((!tty) || (!tty->termios)) {
919 		dbg("%s - no tty structures", __FUNCTION__);
920 		return;
921 	}
922 
923 	spin_lock_irqsave(&priv->lock, flags);
924 	if (!priv->termios_initialized) {
925 		if (priv->chiptype == CT_EARTHMATE) {
926 			*(tty->termios) = tty_std_termios;
927 			tty->termios->c_cflag = B4800 | CS8 | CREAD | HUPCL | CLOCAL;
928 		} else if (priv->chiptype == CT_CYPHIDCOM) {
929 			*(tty->termios) = tty_std_termios;
930 			tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
931 		}
932 		priv->termios_initialized = 1;
933 	}
934 	spin_unlock_irqrestore(&priv->lock, flags);
935 
936 	cflag = tty->termios->c_cflag;
937 	iflag = tty->termios->c_iflag;
938 
939 	/* check if there are new settings */
940 	if (old_termios) {
941 		if ((cflag != old_termios->c_cflag) ||
942 		    (RELEVANT_IFLAG(iflag) != RELEVANT_IFLAG(old_termios->c_iflag))) {
943 			dbg("%s - attempting to set new termios settings", __FUNCTION__);
944 			/* should make a copy of this in case something goes wrong in the function, we can restore it */
945 			spin_lock_irqsave(&priv->lock, flags);
946 			priv->tmp_termios = *(tty->termios);
947 			spin_unlock_irqrestore(&priv->lock, flags);
948 		} else {
949 			dbg("%s - nothing to do, exiting", __FUNCTION__);
950 			return;
951 		}
952 	} else
953 		return;
954 
955 	/* set number of data bits, parity, stop bits */
956 	/* when parity is disabled the parity type bit is ignored */
957 
958 	stop_bits = cflag & CSTOPB ? 1 : 0; /* 1 means 2 stop bits, 0 means 1 stop bit */
959 
960 	if (cflag & PARENB) {
961 		parity_enable = 1;
962 		parity_type = cflag & PARODD ? 1 : 0; /* 1 means odd parity, 0 means even parity */
963 	} else
964 		parity_enable = parity_type = 0;
965 
966 	if (cflag & CSIZE) {
967 		switch (cflag & CSIZE) {
968 			case CS5: data_bits = 0; break;
969 			case CS6: data_bits = 1; break;
970 			case CS7: data_bits = 2; break;
971 			case CS8: data_bits = 3; break;
972 			default: err("%s - CSIZE was set, but not CS5-CS8", __FUNCTION__); data_bits = 3;
973 		}
974 	} else
975 		data_bits = 3;
976 
977 	spin_lock_irqsave(&priv->lock, flags);
978 	oldlines = priv->line_control;
979 	if ((cflag & CBAUD) == B0) {
980 		/* drop dtr and rts */
981 		dbg("%s - dropping the lines, baud rate 0bps", __FUNCTION__);
982 		baud_mask = B0;
983 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
984 	} else {
985 		baud_mask = (cflag & CBAUD);
986 		switch(baud_mask) {
987 			case B300: dbg("%s - setting baud 300bps", __FUNCTION__); break;
988 			case B600: dbg("%s - setting baud 600bps", __FUNCTION__); break;
989 			case B1200: dbg("%s - setting baud 1200bps", __FUNCTION__); break;
990 			case B2400: dbg("%s - setting baud 2400bps", __FUNCTION__); break;
991 			case B4800: dbg("%s - setting baud 4800bps", __FUNCTION__); break;
992 			case B9600: dbg("%s - setting baud 9600bps", __FUNCTION__); break;
993 			case B19200: dbg("%s - setting baud 19200bps", __FUNCTION__); break;
994 			case B38400: dbg("%s - setting baud 38400bps", __FUNCTION__); break;
995 			case B57600: dbg("%s - setting baud 57600bps", __FUNCTION__); break;
996 			case B115200: dbg("%s - setting baud 115200bps", __FUNCTION__); break;
997 			default: dbg("%s - unknown masked baud rate", __FUNCTION__);
998 		}
999 		priv->line_control |= CONTROL_DTR;
1000 
1001 		/* toggle CRTSCTS? - don't do this if being called from cypress_open */
1002 		if (!priv->calledfromopen) {
1003 			if (cflag & CRTSCTS)
1004 				priv->line_control |= CONTROL_RTS;
1005 			else
1006 				priv->line_control &= ~CONTROL_RTS;
1007 		}
1008 	}
1009 	spin_unlock_irqrestore(&priv->lock, flags);
1010 
1011 	dbg("%s - sending %d stop_bits, %d parity_enable, %d parity_type, %d data_bits (+5)", __FUNCTION__,
1012 	    stop_bits, parity_enable, parity_type, data_bits);
1013 
1014 	cypress_serial_control(port, baud_mask, data_bits, stop_bits, parity_enable,
1015 			       parity_type, 0, CYPRESS_SET_CONFIG);
1016 
1017 	msleep(50);			/* give some time between change and read (50ms) */
1018 
1019 	/* we perform a CYPRESS_GET_CONFIG so that the current settings are filled into the private structure
1020          * this should confirm that all is working if it returns what we just set */
1021 	cypress_serial_control(port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
1022 
1023 	/* Here we can define custom tty settings for devices
1024          *
1025          * the main tty termios flag base comes from empeg.c
1026          */
1027 
1028 	spin_lock_irqsave(&priv->lock, flags);
1029 	if ( (priv->chiptype == CT_EARTHMATE) && (priv->baud_rate == 4800) ) {
1030 
1031 		dbg("Using custom termios settings for a baud rate of 4800bps.");
1032 		/* define custom termios settings for NMEA protocol */
1033 
1034 
1035 		tty->termios->c_iflag /* input modes - */
1036 			&= ~(IGNBRK		/* disable ignore break */
1037 			| BRKINT		/* disable break causes interrupt */
1038 			| PARMRK		/* disable mark parity errors */
1039 			| ISTRIP		/* disable clear high bit of input characters */
1040 			| INLCR			/* disable translate NL to CR */
1041 			| IGNCR			/* disable ignore CR */
1042 			| ICRNL			/* disable translate CR to NL */
1043 			| IXON);		/* disable enable XON/XOFF flow control */
1044 
1045 		tty->termios->c_oflag /* output modes */
1046 			&= ~OPOST;		/* disable postprocess output characters */
1047 
1048 		tty->termios->c_lflag /* line discipline modes */
1049 			&= ~(ECHO 		/* disable echo input characters */
1050 			| ECHONL		/* disable echo new line */
1051 			| ICANON		/* disable erase, kill, werase, and rprnt special characters */
1052 			| ISIG			/* disable interrupt, quit, and suspend special characters */
1053 			| IEXTEN);		/* disable non-POSIX special characters */
1054 
1055 	} else if (priv->chiptype == CT_CYPHIDCOM) {
1056 
1057 		// Software app handling it for device...
1058 
1059 	}
1060 	linechange = (priv->line_control != oldlines);
1061 	spin_unlock_irqrestore(&priv->lock, flags);
1062 
1063 	/* if necessary, set lines */
1064 	if (!priv->calledfromopen && linechange) {
1065 		priv->cmd_ctrl = 1;
1066 		cypress_write(port, NULL, 0);
1067 	}
1068 
1069 	if (priv->calledfromopen)
1070 		priv->calledfromopen = 0;
1071 
1072 } /* cypress_set_termios */
1073 
1074 
1075 /* returns amount of data still left in soft buffer */
1076 static int cypress_chars_in_buffer(struct usb_serial_port *port)
1077 {
1078 	struct cypress_private *priv = usb_get_serial_port_data(port);
1079 	int chars = 0;
1080 	unsigned long flags;
1081 
1082 	dbg("%s - port %d", __FUNCTION__, port->number);
1083 
1084 	spin_lock_irqsave(&priv->lock, flags);
1085 	chars = cypress_buf_data_avail(priv->buf);
1086 	spin_unlock_irqrestore(&priv->lock, flags);
1087 
1088 	dbg("%s - returns %d", __FUNCTION__, chars);
1089 	return chars;
1090 }
1091 
1092 
1093 static void cypress_throttle (struct usb_serial_port *port)
1094 {
1095 	struct cypress_private *priv = usb_get_serial_port_data(port);
1096 	unsigned long flags;
1097 
1098 	dbg("%s - port %d", __FUNCTION__, port->number);
1099 
1100 	spin_lock_irqsave(&priv->lock, flags);
1101 	priv->rx_flags = THROTTLED;
1102 	spin_unlock_irqrestore(&priv->lock, flags);
1103 }
1104 
1105 
1106 static void cypress_unthrottle (struct usb_serial_port *port)
1107 {
1108 	struct cypress_private *priv = usb_get_serial_port_data(port);
1109 	int actually_throttled, result;
1110 	unsigned long flags;
1111 
1112 	dbg("%s - port %d", __FUNCTION__, port->number);
1113 
1114 	spin_lock_irqsave(&priv->lock, flags);
1115 	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
1116 	priv->rx_flags = 0;
1117 	spin_unlock_irqrestore(&priv->lock, flags);
1118 
1119 	if (actually_throttled) {
1120 		port->interrupt_in_urb->dev = port->serial->dev;
1121 
1122 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1123 		if (result)
1124 			dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
1125 	}
1126 }
1127 
1128 
1129 static void cypress_read_int_callback(struct urb *urb, struct pt_regs *regs)
1130 {
1131 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
1132 	struct cypress_private *priv = usb_get_serial_port_data(port);
1133 	struct tty_struct *tty;
1134 	unsigned char *data = urb->transfer_buffer;
1135 	unsigned long flags;
1136 	char tty_flag = TTY_NORMAL;
1137 	int havedata = 0;
1138 	int bytes = 0;
1139 	int result;
1140 	int i = 0;
1141 
1142 	dbg("%s - port %d", __FUNCTION__, port->number);
1143 
1144 	if (urb->status) {
1145 		dbg("%s - nonzero read status received: %d", __FUNCTION__, urb->status);
1146 		return;
1147 	}
1148 
1149 	spin_lock_irqsave(&priv->lock, flags);
1150 	if (priv->rx_flags & THROTTLED) {
1151 		dbg("%s - now throttling", __FUNCTION__);
1152 		priv->rx_flags |= ACTUALLY_THROTTLED;
1153 		spin_unlock_irqrestore(&priv->lock, flags);
1154 		return;
1155 	}
1156 	spin_unlock_irqrestore(&priv->lock, flags);
1157 
1158 	tty = port->tty;
1159 	if (!tty) {
1160 		dbg("%s - bad tty pointer - exiting", __FUNCTION__);
1161 		return;
1162 	}
1163 
1164 	spin_lock_irqsave(&priv->lock, flags);
1165 	switch(urb->actual_length) {
1166 		case 32:
1167 			// This is for the CY7C64013...
1168 			priv->current_status = data[0] & 0xF8;
1169 			bytes = data[1]+2;
1170 			i=2;
1171 			if (bytes > 2)
1172 				havedata = 1;
1173 			break;
1174 		case 8:
1175 			// This is for the CY7C63743...
1176 			priv->current_status = data[0] & 0xF8;
1177 			bytes = (data[0] & 0x07)+1;
1178 			i=1;
1179 			if (bytes > 1)
1180 				havedata = 1;
1181 			break;
1182 		default:
1183 			dbg("%s - wrong packet size - received %d bytes", __FUNCTION__, urb->actual_length);
1184 			spin_unlock_irqrestore(&priv->lock, flags);
1185 			goto continue_read;
1186 	}
1187 	spin_unlock_irqrestore(&priv->lock, flags);
1188 
1189 	usb_serial_debug_data (debug, &port->dev, __FUNCTION__, urb->actual_length, data);
1190 
1191 	spin_lock_irqsave(&priv->lock, flags);
1192 	/* check to see if status has changed */
1193 	if (priv != NULL) {
1194 		if (priv->current_status != priv->prev_status) {
1195 			priv->diff_status |= priv->current_status ^ priv->prev_status;
1196 			wake_up_interruptible(&priv->delta_msr_wait);
1197 			priv->prev_status = priv->current_status;
1198 		}
1199 	}
1200 	spin_unlock_irqrestore(&priv->lock, flags);
1201 
1202 	/* hangup, as defined in acm.c... this might be a bad place for it though */
1203 	if (tty && !(tty->termios->c_cflag & CLOCAL) && !(priv->current_status & UART_CD)) {
1204 		dbg("%s - calling hangup", __FUNCTION__);
1205 		tty_hangup(tty);
1206 		goto continue_read;
1207 	}
1208 
1209 	/* There is one error bit... I'm assuming it is a parity error indicator
1210 	 * as the generic firmware will set this bit to 1 if a parity error occurs.
1211 	 * I can not find reference to any other error events.
1212 	 *
1213 	 */
1214 	spin_lock_irqsave(&priv->lock, flags);
1215 	if (priv->current_status & CYP_ERROR) {
1216 		spin_unlock_irqrestore(&priv->lock, flags);
1217 		tty_flag = TTY_PARITY;
1218 		dbg("%s - Parity Error detected", __FUNCTION__);
1219 	} else
1220 		spin_unlock_irqrestore(&priv->lock, flags);
1221 
1222 	/* process read if there is data other than line status */
1223 	if (tty && (bytes > i)) {
1224 		for (; i < bytes ; ++i) {
1225 			dbg("pushing byte number %d - %d - %c",i,data[i],data[i]);
1226 			if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
1227 				tty_flip_buffer_push(tty);
1228 			}
1229 			tty_insert_flip_char(tty, data[i], tty_flag);
1230 		}
1231 		tty_flip_buffer_push(port->tty);
1232 	}
1233 
1234 	spin_lock_irqsave(&priv->lock, flags);
1235 	priv->bytes_in += bytes;  /* control and status byte(s) are also counted */
1236 	spin_unlock_irqrestore(&priv->lock, flags);
1237 
1238 continue_read:
1239 
1240 	/* Continue trying to always read... unless the port has closed.  */
1241 
1242 	if (port->open_count > 0) {
1243 	usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1244 		usb_rcvintpipe(port->serial->dev, port->interrupt_in_endpointAddress),
1245 		port->interrupt_in_urb->transfer_buffer,
1246 		port->interrupt_in_urb->transfer_buffer_length,
1247 		cypress_read_int_callback, port,
1248 		port->interrupt_in_urb->interval);
1249 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1250 	if (result)
1251 		dev_err(&urb->dev->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
1252 	}
1253 
1254 	return;
1255 } /* cypress_read_int_callback */
1256 
1257 
1258 static void cypress_write_int_callback(struct urb *urb, struct pt_regs *regs)
1259 {
1260 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
1261 	struct cypress_private *priv = usb_get_serial_port_data(port);
1262 	int result;
1263 
1264 	dbg("%s - port %d", __FUNCTION__, port->number);
1265 
1266 	switch (urb->status) {
1267 		case 0:
1268 			/* success */
1269 			break;
1270 		case -ECONNRESET:
1271 		case -ENOENT:
1272 		case -ESHUTDOWN:
1273 			/* this urb is terminated, clean up */
1274 			dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
1275 			priv->write_urb_in_use = 0;
1276 			return;
1277 		default:
1278 			/* error in the urb, so we have to resubmit it */
1279 			dbg("%s - Overflow in write", __FUNCTION__);
1280 			dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
1281 			port->interrupt_out_urb->transfer_buffer_length = 1;
1282 			port->interrupt_out_urb->dev = port->serial->dev;
1283 			result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
1284 			if (result)
1285 				dev_err(&urb->dev->dev, "%s - failed resubmitting write urb, error %d\n",
1286 					__FUNCTION__, result);
1287 			else
1288 				return;
1289 	}
1290 
1291 	priv->write_urb_in_use = 0;
1292 
1293 	/* send any buffered data */
1294 	cypress_send(port);
1295 }
1296 
1297 
1298 /*****************************************************************************
1299  * Write buffer functions - buffering code from pl2303 used
1300  *****************************************************************************/
1301 
1302 /*
1303  * cypress_buf_alloc
1304  *
1305  * Allocate a circular buffer and all associated memory.
1306  */
1307 
1308 static struct cypress_buf *cypress_buf_alloc(unsigned int size)
1309 {
1310 
1311 	struct cypress_buf *cb;
1312 
1313 
1314 	if (size == 0)
1315 		return NULL;
1316 
1317 	cb = (struct cypress_buf *)kmalloc(sizeof(struct cypress_buf), GFP_KERNEL);
1318 	if (cb == NULL)
1319 		return NULL;
1320 
1321 	cb->buf_buf = kmalloc(size, GFP_KERNEL);
1322 	if (cb->buf_buf == NULL) {
1323 		kfree(cb);
1324 		return NULL;
1325 	}
1326 
1327 	cb->buf_size = size;
1328 	cb->buf_get = cb->buf_put = cb->buf_buf;
1329 
1330 	return cb;
1331 
1332 }
1333 
1334 
1335 /*
1336  * cypress_buf_free
1337  *
1338  * Free the buffer and all associated memory.
1339  */
1340 
1341 static void cypress_buf_free(struct cypress_buf *cb)
1342 {
1343 	if (cb != NULL) {
1344 		if (cb->buf_buf != NULL)
1345 			kfree(cb->buf_buf);
1346 		kfree(cb);
1347 	}
1348 }
1349 
1350 
1351 /*
1352  * cypress_buf_clear
1353  *
1354  * Clear out all data in the circular buffer.
1355  */
1356 
1357 static void cypress_buf_clear(struct cypress_buf *cb)
1358 {
1359 	if (cb != NULL)
1360 		cb->buf_get = cb->buf_put;
1361 		/* equivalent to a get of all data available */
1362 }
1363 
1364 
1365 /*
1366  * cypress_buf_data_avail
1367  *
1368  * Return the number of bytes of data available in the circular
1369  * buffer.
1370  */
1371 
1372 static unsigned int cypress_buf_data_avail(struct cypress_buf *cb)
1373 {
1374 	if (cb != NULL)
1375 		return ((cb->buf_size + cb->buf_put - cb->buf_get) % cb->buf_size);
1376 	else
1377 		return 0;
1378 }
1379 
1380 
1381 /*
1382  * cypress_buf_space_avail
1383  *
1384  * Return the number of bytes of space available in the circular
1385  * buffer.
1386  */
1387 
1388 static unsigned int cypress_buf_space_avail(struct cypress_buf *cb)
1389 {
1390 	if (cb != NULL)
1391 		return ((cb->buf_size + cb->buf_get - cb->buf_put - 1) % cb->buf_size);
1392 	else
1393 		return 0;
1394 }
1395 
1396 
1397 /*
1398  * cypress_buf_put
1399  *
1400  * Copy data data from a user buffer and put it into the circular buffer.
1401  * Restrict to the amount of space available.
1402  *
1403  * Return the number of bytes copied.
1404  */
1405 
1406 static unsigned int cypress_buf_put(struct cypress_buf *cb, const char *buf,
1407 	unsigned int count)
1408 {
1409 
1410 	unsigned int len;
1411 
1412 
1413 	if (cb == NULL)
1414 		return 0;
1415 
1416 	len  = cypress_buf_space_avail(cb);
1417 	if (count > len)
1418 		count = len;
1419 
1420 	if (count == 0)
1421 		return 0;
1422 
1423 	len = cb->buf_buf + cb->buf_size - cb->buf_put;
1424 	if (count > len) {
1425 		memcpy(cb->buf_put, buf, len);
1426 		memcpy(cb->buf_buf, buf+len, count - len);
1427 		cb->buf_put = cb->buf_buf + count - len;
1428 	} else {
1429 		memcpy(cb->buf_put, buf, count);
1430 		if (count < len)
1431 			cb->buf_put += count;
1432 		else /* count == len */
1433 			cb->buf_put = cb->buf_buf;
1434 	}
1435 
1436 	return count;
1437 
1438 }
1439 
1440 
1441 /*
1442  * cypress_buf_get
1443  *
1444  * Get data from the circular buffer and copy to the given buffer.
1445  * Restrict to the amount of data available.
1446  *
1447  * Return the number of bytes copied.
1448  */
1449 
1450 static unsigned int cypress_buf_get(struct cypress_buf *cb, char *buf,
1451 	unsigned int count)
1452 {
1453 
1454 	unsigned int len;
1455 
1456 
1457 	if (cb == NULL)
1458 		return 0;
1459 
1460 	len = cypress_buf_data_avail(cb);
1461 	if (count > len)
1462 		count = len;
1463 
1464 	if (count == 0)
1465 		return 0;
1466 
1467 	len = cb->buf_buf + cb->buf_size - cb->buf_get;
1468 	if (count > len) {
1469 		memcpy(buf, cb->buf_get, len);
1470 		memcpy(buf+len, cb->buf_buf, count - len);
1471 		cb->buf_get = cb->buf_buf + count - len;
1472 	} else {
1473 		memcpy(buf, cb->buf_get, count);
1474 		if (count < len)
1475 			cb->buf_get += count;
1476 		else /* count == len */
1477 			cb->buf_get = cb->buf_buf;
1478 	}
1479 
1480 	return count;
1481 
1482 }
1483 
1484 /*****************************************************************************
1485  * Module functions
1486  *****************************************************************************/
1487 
1488 static int __init cypress_init(void)
1489 {
1490 	int retval;
1491 
1492 	dbg("%s", __FUNCTION__);
1493 
1494 	retval = usb_serial_register(&cypress_earthmate_device);
1495 	if (retval)
1496 		goto failed_em_register;
1497 	retval = usb_serial_register(&cypress_hidcom_device);
1498 	if (retval)
1499 		goto failed_hidcom_register;
1500 	retval = usb_register(&cypress_driver);
1501 	if (retval)
1502 		goto failed_usb_register;
1503 
1504 	info(DRIVER_DESC " " DRIVER_VERSION);
1505 	return 0;
1506 failed_usb_register:
1507 	usb_deregister(&cypress_driver);
1508 failed_hidcom_register:
1509 	usb_serial_deregister(&cypress_hidcom_device);
1510 failed_em_register:
1511 	usb_serial_deregister(&cypress_earthmate_device);
1512 
1513 	return retval;
1514 }
1515 
1516 
1517 static void __exit cypress_exit (void)
1518 {
1519 	dbg("%s", __FUNCTION__);
1520 
1521 	usb_deregister (&cypress_driver);
1522 	usb_serial_deregister (&cypress_earthmate_device);
1523 	usb_serial_deregister (&cypress_hidcom_device);
1524 }
1525 
1526 
1527 module_init(cypress_init);
1528 module_exit(cypress_exit);
1529 
1530 MODULE_AUTHOR( DRIVER_AUTHOR );
1531 MODULE_DESCRIPTION( DRIVER_DESC );
1532 MODULE_VERSION( DRIVER_VERSION );
1533 MODULE_LICENSE("GPL");
1534 
1535 module_param(debug, bool, S_IRUGO | S_IWUSR);
1536 MODULE_PARM_DESC(debug, "Debug enabled or not");
1537 module_param(stats, bool, S_IRUGO | S_IWUSR);
1538 MODULE_PARM_DESC(stats, "Enable statistics or not");
1539