xref: /linux/drivers/usb/serial/cypress_m8.c (revision 36ca1195ad7f760a6af3814cb002bd3a3d4b4db1)
1 /*
2  * USB Cypress M8 driver
3  *
4  * 	Copyright (C) 2004
5  * 	    Lonnie Mendez (dignome@gmail.com)
6  *	Copyright (C) 2003,2004
7  *	    Neil Whelchel (koyama@firstlight.net)
8  *
9  * 	This program is free software; you can redistribute it and/or modify
10  * 	it under the terms of the GNU General Public License as published by
11  * 	the Free Software Foundation; either version 2 of the License, or
12  * 	(at your option) any later version.
13  *
14  * See Documentation/usb/usb-serial.txt for more information on using this driver
15  *
16  * See http://geocities.com/i0xox0i for information on this driver and the
17  * earthmate usb device.
18  *
19  *  Lonnie Mendez <dignome@gmail.com>
20  *  4-29-2005
21  *	Fixed problem where setting or retreiving the serial config would fail with
22  * 	EPIPE.  Removed CRTS toggling so the driver behaves more like other usbserial
23  * 	adapters.  Issued new interval of 1ms instead of the default 10ms.  As a
24  * 	result, transfer speed has been substantially increased.  From avg. 850bps to
25  * 	avg. 3300bps.  initial termios has also been modified.  Cleaned up code and
26  * 	formatting issues so it is more readable.  Replaced the C++ style comments.
27  *
28  *  Lonnie Mendez <dignome@gmail.com>
29  *  12-15-2004
30  *	Incorporated write buffering from pl2303 driver.  Fixed bug with line
31  *	handling so both lines are raised in cypress_open. (was dropping rts)
32  *      Various code cleanups made as well along with other misc bug fixes.
33  *
34  *  Lonnie Mendez <dignome@gmail.com>
35  *  04-10-2004
36  *	Driver modified to support dynamic line settings.  Various improvments
37  *      and features.
38  *
39  *  Neil Whelchel
40  *  10-2003
41  *	Driver first released.
42  *
43  */
44 
45 /* Thanks to Neil Whelchel for writing the first cypress m8 implementation for linux. */
46 /* Thanks to cypress for providing references for the hid reports. */
47 /* Thanks to Jiang Zhang for providing links and for general help. */
48 /* Code originates and was built up from ftdi_sio, belkin, pl2303 and others. */
49 
50 
51 #include <linux/config.h>
52 #include <linux/kernel.h>
53 #include <linux/errno.h>
54 #include <linux/init.h>
55 #include <linux/slab.h>
56 #include <linux/tty.h>
57 #include <linux/tty_driver.h>
58 #include <linux/tty_flip.h>
59 #include <linux/module.h>
60 #include <linux/moduleparam.h>
61 #include <linux/spinlock.h>
62 #include <linux/usb.h>
63 #include <linux/serial.h>
64 #include <linux/delay.h>
65 #include <asm/uaccess.h>
66 
67 #include "usb-serial.h"
68 #include "cypress_m8.h"
69 
70 
71 #ifdef CONFIG_USB_SERIAL_DEBUG
72 	static int debug = 1;
73 #else
74 	static int debug;
75 #endif
76 static int stats;
77 static int interval;
78 
79 /*
80  * Version Information
81  */
82 #define DRIVER_VERSION "v1.09"
83 #define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
84 #define DRIVER_DESC "Cypress USB to Serial Driver"
85 
86 /* write buffer size defines */
87 #define CYPRESS_BUF_SIZE	1024
88 #define CYPRESS_CLOSING_WAIT	(30*HZ)
89 
90 static struct usb_device_id id_table_earthmate [] = {
91 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
92 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
93 	{ }						/* Terminating entry */
94 };
95 
96 static struct usb_device_id id_table_cyphidcomrs232 [] = {
97 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
98 	{ }						/* Terminating entry */
99 };
100 
101 static struct usb_device_id id_table_combined [] = {
102 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
103 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
104 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
105 	{ }						/* Terminating entry */
106 };
107 
108 MODULE_DEVICE_TABLE (usb, id_table_combined);
109 
110 static struct usb_driver cypress_driver = {
111 	.name =		"cypress",
112 	.probe =	usb_serial_probe,
113 	.disconnect =	usb_serial_disconnect,
114 	.id_table =	id_table_combined,
115 };
116 
117 struct cypress_private {
118 	spinlock_t lock;		   /* private lock */
119 	int chiptype;			   /* identifier of device, for quirks/etc */
120 	int bytes_in;			   /* used for statistics */
121 	int bytes_out;			   /* used for statistics */
122 	int cmd_count;			   /* used for statistics */
123 	int cmd_ctrl;			   /* always set this to 1 before issuing a command */
124 	struct cypress_buf *buf;	   /* write buffer */
125 	int write_urb_in_use;		   /* write urb in use indicator */
126 	int termios_initialized;
127 	__u8 line_control;	   	   /* holds dtr / rts value */
128 	__u8 current_status;	   	   /* received from last read - info on dsr,cts,cd,ri,etc */
129 	__u8 current_config;	   	   /* stores the current configuration byte */
130 	__u8 rx_flags;			   /* throttling - used from whiteheat/ftdi_sio */
131 	int baud_rate;			   /* stores current baud rate in integer form */
132 	int cbr_mask;			   /* stores current baud rate in masked form */
133 	int isthrottled;		   /* if throttled, discard reads */
134 	wait_queue_head_t delta_msr_wait;  /* used for TIOCMIWAIT */
135 	char prev_status, diff_status;	   /* used for TIOCMIWAIT */
136 	/* we pass a pointer to this as the arguement sent to cypress_set_termios old_termios */
137 	struct termios tmp_termios; 	   /* stores the old termios settings */
138 };
139 
140 /* write buffer structure */
141 struct cypress_buf {
142 	unsigned int	buf_size;
143 	char		*buf_buf;
144 	char		*buf_get;
145 	char		*buf_put;
146 };
147 
148 /* function prototypes for the Cypress USB to serial device */
149 static int  cypress_earthmate_startup	(struct usb_serial *serial);
150 static int  cypress_hidcom_startup	(struct usb_serial *serial);
151 static void cypress_shutdown		(struct usb_serial *serial);
152 static int  cypress_open		(struct usb_serial_port *port, struct file *filp);
153 static void cypress_close		(struct usb_serial_port *port, struct file *filp);
154 static int  cypress_write		(struct usb_serial_port *port, const unsigned char *buf, int count);
155 static void cypress_send		(struct usb_serial_port *port);
156 static int  cypress_write_room		(struct usb_serial_port *port);
157 static int  cypress_ioctl		(struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg);
158 static void cypress_set_termios		(struct usb_serial_port *port, struct termios * old);
159 static int  cypress_tiocmget		(struct usb_serial_port *port, struct file *file);
160 static int  cypress_tiocmset		(struct usb_serial_port *port, struct file *file, unsigned int set, unsigned int clear);
161 static int  cypress_chars_in_buffer	(struct usb_serial_port *port);
162 static void cypress_throttle		(struct usb_serial_port *port);
163 static void cypress_unthrottle		(struct usb_serial_port *port);
164 static void cypress_read_int_callback	(struct urb *urb, struct pt_regs *regs);
165 static void cypress_write_int_callback	(struct urb *urb, struct pt_regs *regs);
166 /* baud helper functions */
167 static int	 mask_to_rate		(unsigned mask);
168 static unsigned  rate_to_mask		(int rate);
169 /* write buffer functions */
170 static struct cypress_buf *cypress_buf_alloc(unsigned int size);
171 static void 		  cypress_buf_free(struct cypress_buf *cb);
172 static void		  cypress_buf_clear(struct cypress_buf *cb);
173 static unsigned int	  cypress_buf_data_avail(struct cypress_buf *cb);
174 static unsigned int	  cypress_buf_space_avail(struct cypress_buf *cb);
175 static unsigned int	  cypress_buf_put(struct cypress_buf *cb, const char *buf, unsigned int count);
176 static unsigned int	  cypress_buf_get(struct cypress_buf *cb, char *buf, unsigned int count);
177 
178 
179 static struct usb_serial_device_type cypress_earthmate_device = {
180 	.owner =			THIS_MODULE,
181 	.name =				"DeLorme Earthmate USB",
182 	.short_name =			"earthmate",
183 	.id_table =			id_table_earthmate,
184 	.num_interrupt_in = 		1,
185 	.num_interrupt_out =		1,
186 	.num_bulk_in =			NUM_DONT_CARE,
187 	.num_bulk_out =			NUM_DONT_CARE,
188 	.num_ports =			1,
189 	.attach =			cypress_earthmate_startup,
190 	.shutdown =			cypress_shutdown,
191 	.open =				cypress_open,
192 	.close =			cypress_close,
193 	.write =			cypress_write,
194 	.write_room =			cypress_write_room,
195 	.ioctl =			cypress_ioctl,
196 	.set_termios =			cypress_set_termios,
197 	.tiocmget =			cypress_tiocmget,
198 	.tiocmset =			cypress_tiocmset,
199 	.chars_in_buffer =		cypress_chars_in_buffer,
200 	.throttle =		 	cypress_throttle,
201 	.unthrottle =			cypress_unthrottle,
202 	.read_int_callback =		cypress_read_int_callback,
203 	.write_int_callback =		cypress_write_int_callback,
204 };
205 
206 static struct usb_serial_device_type cypress_hidcom_device = {
207 	.owner =			THIS_MODULE,
208 	.name =				"HID->COM RS232 Adapter",
209 	.short_name =			"cyphidcom",
210 	.id_table =			id_table_cyphidcomrs232,
211 	.num_interrupt_in =		1,
212 	.num_interrupt_out =		1,
213 	.num_bulk_in =			NUM_DONT_CARE,
214 	.num_bulk_out =			NUM_DONT_CARE,
215 	.num_ports =			1,
216 	.attach =			cypress_hidcom_startup,
217 	.shutdown =			cypress_shutdown,
218 	.open =				cypress_open,
219 	.close =			cypress_close,
220 	.write =			cypress_write,
221 	.write_room =			cypress_write_room,
222 	.ioctl =			cypress_ioctl,
223 	.set_termios =			cypress_set_termios,
224 	.tiocmget =			cypress_tiocmget,
225 	.tiocmset =			cypress_tiocmset,
226 	.chars_in_buffer =		cypress_chars_in_buffer,
227 	.throttle =			cypress_throttle,
228 	.unthrottle =			cypress_unthrottle,
229 	.read_int_callback =		cypress_read_int_callback,
230 	.write_int_callback =		cypress_write_int_callback,
231 };
232 
233 
234 /*****************************************************************************
235  * Cypress serial helper functions
236  *****************************************************************************/
237 
238 
239 /* This function can either set or retrieve the current serial line settings */
240 static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_mask, int data_bits, int stop_bits,
241 				   int parity_enable, int parity_type, int reset, int cypress_request_type)
242 {
243 	int new_baudrate = 0, retval = 0, tries = 0;
244 	struct cypress_private *priv;
245 	__u8 feature_buffer[8];
246 	unsigned long flags;
247 
248 	dbg("%s", __FUNCTION__);
249 
250 	priv = usb_get_serial_port_data(port);
251 
252 	switch(cypress_request_type) {
253 		case CYPRESS_SET_CONFIG:
254 
255 			/*
256 			 * The general purpose firmware for the Cypress M8 allows for a maximum speed
257  			 * of 57600bps (I have no idea whether DeLorme chose to use the general purpose
258 			 * firmware or not), if you need to modify this speed setting for your own
259 			 * project please add your own chiptype and modify the code likewise.  The
260 			 * Cypress HID->COM device will work successfully up to 115200bps (but the
261 			 * actual throughput is around 3kBps).
262 			 */
263 			if (baud_mask != priv->cbr_mask) {
264 				dbg("%s - baud rate is changing", __FUNCTION__);
265 				if ( priv->chiptype == CT_EARTHMATE ) {
266 					/* 300 and 600 baud rates are supported under the generic firmware,
267 					 * but are not used with NMEA and SiRF protocols */
268 
269 					if ( (baud_mask == B300) || (baud_mask == B600) ) {
270 						err("%s - failed setting baud rate, unsupported speed",
271 						    __FUNCTION__);
272 						new_baudrate = priv->baud_rate;
273 					} else if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
274 						err("%s - failed setting baud rate, unsupported speed",
275 						    __FUNCTION__);
276 						new_baudrate = priv->baud_rate;
277 					}
278 				} else if (priv->chiptype == CT_CYPHIDCOM) {
279 					if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
280 						err("%s - failed setting baud rate, unsupported speed",
281 						    __FUNCTION__);
282 						new_baudrate = priv->baud_rate;
283 					}
284 				} else if (priv->chiptype == CT_GENERIC) {
285 					if ( (new_baudrate = mask_to_rate(baud_mask)) == -1) {
286 						err("%s - failed setting baud rate, unsupported speed",
287 						    __FUNCTION__);
288 						new_baudrate = priv->baud_rate;
289 					}
290 				} else {
291 					info("%s - please define your chiptype", __FUNCTION__);
292 					new_baudrate = priv->baud_rate;
293 				}
294 			} else {  /* baud rate not changing, keep the old */
295 				new_baudrate = priv->baud_rate;
296 			}
297 			dbg("%s - baud rate is being sent as %d", __FUNCTION__, new_baudrate);
298 
299 			memset(feature_buffer, 0, 8);
300 			/* fill the feature_buffer with new configuration */
301 			*((u_int32_t *)feature_buffer) = new_baudrate;
302 
303 			feature_buffer[4] |= data_bits;   /* assign data bits in 2 bit space ( max 3 ) */
304 			/* 1 bit gap */
305 			feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
306 			feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
307 			feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
308 			/* 1 bit gap */
309 			feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
310 
311 			dbg("%s - device is being sent this feature report:", __FUNCTION__);
312 			dbg("%s - %02X - %02X - %02X - %02X - %02X", __FUNCTION__, feature_buffer[0], feature_buffer[1],
313 		            feature_buffer[2], feature_buffer[3], feature_buffer[4]);
314 
315 			do {
316 			retval = usb_control_msg (port->serial->dev, usb_sndctrlpipe(port->serial->dev, 0),
317 					  	  HID_REQ_SET_REPORT, USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
318 						  	  0x0300, 0, feature_buffer, 8, 500);
319 
320 				if (tries++ >= 3)
321 					break;
322 
323 				if (retval == EPIPE)
324 					usb_clear_halt(port->serial->dev, 0x00);
325 			} while (retval != 8 && retval != ENODEV);
326 
327 			if (retval != 8)
328 				err("%s - failed sending serial line settings - %d", __FUNCTION__, retval);
329 			else {
330 				spin_lock_irqsave(&priv->lock, flags);
331 				priv->baud_rate = new_baudrate;
332 				priv->cbr_mask = baud_mask;
333 				priv->current_config = feature_buffer[4];
334 				spin_unlock_irqrestore(&priv->lock, flags);
335 			}
336 		break;
337 		case CYPRESS_GET_CONFIG:
338 			dbg("%s - retreiving serial line settings", __FUNCTION__);
339 			/* set initial values in feature buffer */
340 			memset(feature_buffer, 0, 8);
341 
342 			do {
343 			retval = usb_control_msg (port->serial->dev, usb_rcvctrlpipe(port->serial->dev, 0),
344 						  HID_REQ_GET_REPORT, USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
345 							  0x0300, 0, feature_buffer, 8, 500);
346 
347 				if (tries++ >= 3)
348 					break;
349 
350 				if (retval == EPIPE)
351 					usb_clear_halt(port->serial->dev, 0x00);
352 			} while (retval != 5 && retval != ENODEV);
353 
354 			if (retval != 5) {
355 				err("%s - failed to retreive serial line settings - %d", __FUNCTION__, retval);
356 				return retval;
357 			} else {
358 				spin_lock_irqsave(&priv->lock, flags);
359 
360 				/* store the config in one byte, and later use bit masks to check values */
361 				priv->current_config = feature_buffer[4];
362 				priv->baud_rate = *((u_int32_t *)feature_buffer);
363 
364 				if ( (priv->cbr_mask = rate_to_mask(priv->baud_rate)) == 0x40)
365 					dbg("%s - failed setting the baud mask (not defined)", __FUNCTION__);
366 				spin_unlock_irqrestore(&priv->lock, flags);
367 			}
368 	}
369 	spin_lock_irqsave(&priv->lock, flags);
370 	++priv->cmd_count;
371 	spin_unlock_irqrestore(&priv->lock, flags);
372 
373 	return retval;
374 } /* cypress_serial_control */
375 
376 
377 /* given a baud mask, it will return integer baud on success */
378 static int mask_to_rate (unsigned mask)
379 {
380 	int rate;
381 
382 	switch (mask) {
383 		case B0: rate = 0; break;
384 		case B300: rate = 300; break;
385 		case B600: rate = 600; break;
386 		case B1200: rate = 1200; break;
387 		case B2400: rate = 2400; break;
388 		case B4800: rate = 4800; break;
389 		case B9600: rate = 9600; break;
390 		case B19200: rate = 19200; break;
391 		case B38400: rate = 38400; break;
392 		case B57600: rate = 57600; break;
393 		case B115200: rate = 115200; break;
394 		default: rate = -1;
395 	}
396 
397 	return rate;
398 }
399 
400 
401 static unsigned rate_to_mask (int rate)
402 {
403 	unsigned mask;
404 
405 	switch (rate) {
406 		case 0: mask = B0; break;
407 		case 300: mask = B300; break;
408 		case 600: mask = B600; break;
409 		case 1200: mask = B1200; break;
410 		case 2400: mask = B2400; break;
411 		case 4800: mask = B4800; break;
412 		case 9600: mask = B9600; break;
413 		case 19200: mask = B19200; break;
414 		case 38400: mask = B38400; break;
415 		case 57600: mask = B57600; break;
416 		case 115200: mask = B115200; break;
417 		default: mask = 0x40;
418 	}
419 
420 	return mask;
421 }
422 /*****************************************************************************
423  * Cypress serial driver functions
424  *****************************************************************************/
425 
426 
427 static int generic_startup (struct usb_serial *serial)
428 {
429 	struct cypress_private *priv;
430 
431 	dbg("%s - port %d", __FUNCTION__, serial->port[0]->number);
432 
433 	priv = kmalloc(sizeof (struct cypress_private), GFP_KERNEL);
434 	if (!priv)
435 		return -ENOMEM;
436 
437 	memset(priv, 0x00, sizeof (struct cypress_private));
438 	spin_lock_init(&priv->lock);
439 	priv->buf = cypress_buf_alloc(CYPRESS_BUF_SIZE);
440 	if (priv->buf == NULL) {
441 		kfree(priv);
442 		return -ENOMEM;
443 	}
444 	init_waitqueue_head(&priv->delta_msr_wait);
445 
446 	usb_reset_configuration (serial->dev);
447 
448 	interval = 1;
449 	priv->cmd_ctrl = 0;
450 	priv->line_control = 0;
451 	priv->termios_initialized = 0;
452 	priv->rx_flags = 0;
453 	priv->cbr_mask = B300;
454 	usb_set_serial_port_data(serial->port[0], priv);
455 
456 	return (0);
457 }
458 
459 
460 static int cypress_earthmate_startup (struct usb_serial *serial)
461 {
462 	struct cypress_private *priv;
463 
464 	dbg("%s", __FUNCTION__);
465 
466 	if (generic_startup(serial)) {
467 		dbg("%s - Failed setting up port %d", __FUNCTION__, serial->port[0]->number);
468 		return 1;
469 	}
470 
471 	priv = usb_get_serial_port_data(serial->port[0]);
472 	priv->chiptype = CT_EARTHMATE;
473 
474 	return (0);
475 } /* cypress_earthmate_startup */
476 
477 
478 static int cypress_hidcom_startup (struct usb_serial *serial)
479 {
480 	struct cypress_private *priv;
481 
482 	dbg("%s", __FUNCTION__);
483 
484 	if (generic_startup(serial)) {
485 		dbg("%s - Failed setting up port %d", __FUNCTION__, serial->port[0]->number);
486 		return 1;
487 	}
488 
489 	priv = usb_get_serial_port_data(serial->port[0]);
490 	priv->chiptype = CT_CYPHIDCOM;
491 
492 	return (0);
493 } /* cypress_hidcom_startup */
494 
495 
496 static void cypress_shutdown (struct usb_serial *serial)
497 {
498 	struct cypress_private *priv;
499 
500 	dbg ("%s - port %d", __FUNCTION__, serial->port[0]->number);
501 
502 	/* all open ports are closed at this point */
503 
504 	priv = usb_get_serial_port_data(serial->port[0]);
505 
506 	if (priv) {
507 		cypress_buf_free(priv->buf);
508 		kfree(priv);
509 		usb_set_serial_port_data(serial->port[0], NULL);
510 	}
511 }
512 
513 
514 static int cypress_open (struct usb_serial_port *port, struct file *filp)
515 {
516 	struct cypress_private *priv = usb_get_serial_port_data(port);
517 	struct usb_serial *serial = port->serial;
518 	unsigned long flags;
519 	int result = 0;
520 
521 	dbg("%s - port %d", __FUNCTION__, port->number);
522 
523 	/* clear halts before open */
524 	usb_clear_halt(serial->dev, 0x81);
525 	usb_clear_halt(serial->dev, 0x02);
526 
527 	spin_lock_irqsave(&priv->lock, flags);
528 	/* reset read/write statistics */
529 	priv->bytes_in = 0;
530 	priv->bytes_out = 0;
531 	priv->cmd_count = 0;
532 	priv->rx_flags = 0;
533 	spin_unlock_irqrestore(&priv->lock, flags);
534 
535 	/* setting to zero could cause data loss */
536 	port->tty->low_latency = 1;
537 
538 	/* raise both lines and set termios */
539 	spin_lock_irqsave(&priv->lock, flags);
540 	priv->line_control = CONTROL_DTR | CONTROL_RTS;
541 	priv->cmd_ctrl = 1;
542 	spin_unlock_irqrestore(&priv->lock, flags);
543 	result = cypress_write(port, NULL, 0);
544 
545 	if (result) {
546 		dev_err(&port->dev, "%s - failed setting the control lines - error %d\n", __FUNCTION__, result);
547 		return result;
548 	} else
549 		dbg("%s - success setting the control lines", __FUNCTION__);
550 
551 	cypress_set_termios(port, &priv->tmp_termios);
552 
553 	/* setup the port and start reading from the device */
554 	if(!port->interrupt_in_urb){
555 		err("%s - interrupt_in_urb is empty!", __FUNCTION__);
556 		return(-1);
557 	}
558 
559 	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
560 		usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
561 		port->interrupt_in_urb->transfer_buffer, port->interrupt_in_urb->transfer_buffer_length,
562 		cypress_read_int_callback, port, interval);
563 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
564 
565 	if (result){
566 		dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
567 	}
568 
569 	return result;
570 } /* cypress_open */
571 
572 
573 static void cypress_close(struct usb_serial_port *port, struct file * filp)
574 {
575 	struct cypress_private *priv = usb_get_serial_port_data(port);
576 	unsigned int c_cflag;
577 	unsigned long flags;
578 	int bps;
579 	long timeout;
580 	wait_queue_t wait;
581 
582 	dbg("%s - port %d", __FUNCTION__, port->number);
583 
584 	/* wait for data to drain from buffer */
585 	spin_lock_irqsave(&priv->lock, flags);
586 	timeout = CYPRESS_CLOSING_WAIT;
587 	init_waitqueue_entry(&wait, current);
588 	add_wait_queue(&port->tty->write_wait, &wait);
589 	for (;;) {
590 		set_current_state(TASK_INTERRUPTIBLE);
591 		if (cypress_buf_data_avail(priv->buf) == 0
592 		|| timeout == 0 || signal_pending(current)
593 		|| !usb_get_intfdata(port->serial->interface))
594 			break;
595 		spin_unlock_irqrestore(&priv->lock, flags);
596 		timeout = schedule_timeout(timeout);
597 		spin_lock_irqsave(&priv->lock, flags);
598 	}
599 	set_current_state(TASK_RUNNING);
600 	remove_wait_queue(&port->tty->write_wait, &wait);
601 	/* clear out any remaining data in the buffer */
602 	cypress_buf_clear(priv->buf);
603 	spin_unlock_irqrestore(&priv->lock, flags);
604 
605 	/* wait for characters to drain from device */
606 	bps = tty_get_baud_rate(port->tty);
607 	if (bps > 1200)
608 		timeout = max((HZ*2560)/bps,HZ/10);
609 	else
610 		timeout = 2*HZ;
611 	set_current_state(TASK_INTERRUPTIBLE);
612 	schedule_timeout(timeout);
613 
614 	dbg("%s - stopping urbs", __FUNCTION__);
615 	usb_kill_urb (port->interrupt_in_urb);
616 	usb_kill_urb (port->interrupt_out_urb);
617 
618 	if (port->tty) {
619 		c_cflag = port->tty->termios->c_cflag;
620 		if (c_cflag & HUPCL) {
621 			/* drop dtr and rts */
622 			priv = usb_get_serial_port_data(port);
623 			spin_lock_irqsave(&priv->lock, flags);
624 			priv->line_control = 0;
625 			priv->cmd_ctrl = 1;
626 			spin_unlock_irqrestore(&priv->lock, flags);
627 			cypress_write(port, NULL, 0);
628 		}
629 	}
630 
631 	if (stats)
632 		dev_info (&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
633 		          priv->bytes_in, priv->bytes_out, priv->cmd_count);
634 } /* cypress_close */
635 
636 
637 static int cypress_write(struct usb_serial_port *port, const unsigned char *buf, int count)
638 {
639 	struct cypress_private *priv = usb_get_serial_port_data(port);
640 	unsigned long flags;
641 
642 	dbg("%s - port %d, %d bytes", __FUNCTION__, port->number, count);
643 
644 	/* line control commands, which need to be executed immediately,
645 	   are not put into the buffer for obvious reasons.
646 	 */
647 	if (priv->cmd_ctrl) {
648 		count = 0;
649 		goto finish;
650 	}
651 
652 	if (!count)
653 		return count;
654 
655 	spin_lock_irqsave(&priv->lock, flags);
656 	count = cypress_buf_put(priv->buf, buf, count);
657 	spin_unlock_irqrestore(&priv->lock, flags);
658 
659 finish:
660 	cypress_send(port);
661 
662 	return count;
663 } /* cypress_write */
664 
665 
666 static void cypress_send(struct usb_serial_port *port)
667 {
668 	int count = 0, result, offset, actual_size;
669 	struct cypress_private *priv = usb_get_serial_port_data(port);
670 	unsigned long flags;
671 
672 	dbg("%s - port %d", __FUNCTION__, port->number);
673 	dbg("%s - interrupt out size is %d", __FUNCTION__, port->interrupt_out_size);
674 
675 	spin_lock_irqsave(&priv->lock, flags);
676 	if (priv->write_urb_in_use) {
677 		dbg("%s - can't write, urb in use", __FUNCTION__);
678 		spin_unlock_irqrestore(&priv->lock, flags);
679 		return;
680 	}
681 	spin_unlock_irqrestore(&priv->lock, flags);
682 
683 	/* clear buffer */
684 	memset(port->interrupt_out_urb->transfer_buffer, 0, port->interrupt_out_size);
685 
686 	spin_lock_irqsave(&priv->lock, flags);
687 	switch (port->interrupt_out_size) {
688 		case 32:
689 			/* this is for the CY7C64013... */
690 			offset = 2;
691 			port->interrupt_out_buffer[0] = priv->line_control;
692 			break;
693 		case 8:
694 			/* this is for the CY7C63743... */
695 			offset = 1;
696 			port->interrupt_out_buffer[0] = priv->line_control;
697 			break;
698 		default:
699 			dbg("%s - wrong packet size", __FUNCTION__);
700 			spin_unlock_irqrestore(&priv->lock, flags);
701 			return;
702 	}
703 
704 	if (priv->line_control & CONTROL_RESET)
705 		priv->line_control &= ~CONTROL_RESET;
706 
707 	if (priv->cmd_ctrl) {
708 		priv->cmd_count++;
709 		dbg("%s - line control command being issued", __FUNCTION__);
710 		spin_unlock_irqrestore(&priv->lock, flags);
711 		goto send;
712 	} else
713 		spin_unlock_irqrestore(&priv->lock, flags);
714 
715 	count = cypress_buf_get(priv->buf, &port->interrupt_out_buffer[offset],
716 				port->interrupt_out_size-offset);
717 
718 	if (count == 0) {
719 		return;
720 	}
721 
722 	switch (port->interrupt_out_size) {
723 		case 32:
724 			port->interrupt_out_buffer[1] = count;
725 			break;
726 		case 8:
727 			port->interrupt_out_buffer[0] |= count;
728 	}
729 
730 	dbg("%s - count is %d", __FUNCTION__, count);
731 
732 send:
733 	spin_lock_irqsave(&priv->lock, flags);
734 	priv->write_urb_in_use = 1;
735 	spin_unlock_irqrestore(&priv->lock, flags);
736 
737 	if (priv->cmd_ctrl)
738 		actual_size = 1;
739 	else
740 		actual_size = count + (port->interrupt_out_size == 32 ? 2 : 1);
741 
742 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, port->interrupt_out_size,
743 			      port->interrupt_out_urb->transfer_buffer);
744 
745 	port->interrupt_out_urb->transfer_buffer_length = actual_size;
746 	port->interrupt_out_urb->dev = port->serial->dev;
747 	port->interrupt_out_urb->interval = interval;
748 	result = usb_submit_urb (port->interrupt_out_urb, GFP_ATOMIC);
749 	if (result) {
750 		dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__,
751 			result);
752 		priv->write_urb_in_use = 0;
753 	}
754 
755 	spin_lock_irqsave(&priv->lock, flags);
756 	if (priv->cmd_ctrl) {
757 		priv->cmd_ctrl = 0;
758 	}
759 	priv->bytes_out += count; /* do not count the line control and size bytes */
760 	spin_unlock_irqrestore(&priv->lock, flags);
761 
762 	schedule_work(&port->work);
763 } /* cypress_send */
764 
765 
766 /* returns how much space is available in the soft buffer */
767 static int cypress_write_room(struct usb_serial_port *port)
768 {
769 	struct cypress_private *priv = usb_get_serial_port_data(port);
770 	int room = 0;
771 	unsigned long flags;
772 
773 	dbg("%s - port %d", __FUNCTION__, port->number);
774 
775 	spin_lock_irqsave(&priv->lock, flags);
776 	room = cypress_buf_space_avail(priv->buf);
777 	spin_unlock_irqrestore(&priv->lock, flags);
778 
779 	dbg("%s - returns %d", __FUNCTION__, room);
780 	return room;
781 }
782 
783 
784 static int cypress_tiocmget (struct usb_serial_port *port, struct file *file)
785 {
786 	struct cypress_private *priv = usb_get_serial_port_data(port);
787 	__u8 status, control;
788 	unsigned int result = 0;
789 	unsigned long flags;
790 
791 	dbg("%s - port %d", __FUNCTION__, port->number);
792 
793 	spin_lock_irqsave(&priv->lock, flags);
794 	control = priv->line_control;
795 	status = priv->current_status;
796 	spin_unlock_irqrestore(&priv->lock, flags);
797 
798 	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
799 		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
800 		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
801 		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
802 		| ((status & UART_RI)         ? TIOCM_RI  : 0)
803 		| ((status & UART_CD)         ? TIOCM_CD  : 0);
804 
805 	dbg("%s - result = %x", __FUNCTION__, result);
806 
807 	return result;
808 }
809 
810 
811 static int cypress_tiocmset (struct usb_serial_port *port, struct file *file,
812 			       unsigned int set, unsigned int clear)
813 {
814 	struct cypress_private *priv = usb_get_serial_port_data(port);
815 	unsigned long flags;
816 
817 	dbg("%s - port %d", __FUNCTION__, port->number);
818 
819 	spin_lock_irqsave(&priv->lock, flags);
820 	if (set & TIOCM_RTS)
821 		priv->line_control |= CONTROL_RTS;
822 	if (set & TIOCM_DTR)
823 		priv->line_control |= CONTROL_DTR;
824 	if (clear & TIOCM_RTS)
825 		priv->line_control &= ~CONTROL_RTS;
826 	if (clear & TIOCM_DTR)
827 		priv->line_control &= ~CONTROL_DTR;
828 	spin_unlock_irqrestore(&priv->lock, flags);
829 
830 	priv->cmd_ctrl = 1;
831 	return cypress_write(port, NULL, 0);
832 }
833 
834 
835 static int cypress_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
836 {
837 	struct cypress_private *priv = usb_get_serial_port_data(port);
838 
839 	dbg("%s - port %d, cmd 0x%.4x", __FUNCTION__, port->number, cmd);
840 
841 	switch (cmd) {
842 		case TIOCGSERIAL:
843 			if (copy_to_user((void __user *)arg, port->tty->termios, sizeof(struct termios))) {
844 				return -EFAULT;
845 			}
846 			return (0);
847 			break;
848 		case TIOCSSERIAL:
849 			if (copy_from_user(port->tty->termios, (void __user *)arg, sizeof(struct termios))) {
850 				return -EFAULT;
851 			}
852 			/* here we need to call cypress_set_termios to invoke the new settings */
853 			cypress_set_termios(port, &priv->tmp_termios);
854 			return (0);
855 			break;
856 		/* these are called when setting baud rate from gpsd */
857 		case TCGETS:
858 			if (copy_to_user((void __user *)arg, port->tty->termios, sizeof(struct termios))) {
859 				return -EFAULT;
860 			}
861 			return (0);
862 			break;
863 		case TCSETS:
864 			if (copy_from_user(port->tty->termios, (void __user *)arg, sizeof(struct termios))) {
865 				return -EFAULT;
866 			}
867 			/* here we need to call cypress_set_termios to invoke the new settings */
868 			cypress_set_termios(port, &priv->tmp_termios);
869 			return (0);
870 			break;
871 		/* This code comes from drivers/char/serial.c and ftdi_sio.c */
872 		case TIOCMIWAIT:
873 			while (priv != NULL) {
874 				interruptible_sleep_on(&priv->delta_msr_wait);
875 				/* see if a signal did it */
876 				if (signal_pending(current))
877 					return -ERESTARTSYS;
878 				else {
879 					char diff = priv->diff_status;
880 
881 					if (diff == 0) {
882 						return -EIO; /* no change => error */
883 					}
884 
885 					/* consume all events */
886 					priv->diff_status = 0;
887 
888 					/* return 0 if caller wanted to know about these bits */
889 					if ( ((arg & TIOCM_RNG) && (diff & UART_RI)) ||
890 					     ((arg & TIOCM_DSR) && (diff & UART_DSR)) ||
891 					     ((arg & TIOCM_CD) && (diff & UART_CD)) ||
892 					     ((arg & TIOCM_CTS) && (diff & UART_CTS)) ) {
893 						return 0;
894 					}
895 					/* otherwise caller can't care less about what happened,
896 					 * and so we continue to wait for more events.
897 					 */
898 				}
899 			}
900 			return 0;
901 			break;
902 		default:
903 			break;
904 	}
905 
906 	dbg("%s - arg not supported - it was 0x%04x - check include/asm/ioctls.h", __FUNCTION__, cmd);
907 
908 	return -ENOIOCTLCMD;
909 } /* cypress_ioctl */
910 
911 
912 static void cypress_set_termios (struct usb_serial_port *port, struct termios *old_termios)
913 {
914 	struct cypress_private *priv = usb_get_serial_port_data(port);
915 	struct tty_struct *tty;
916 	int data_bits, stop_bits, parity_type, parity_enable;
917 	unsigned cflag, iflag, baud_mask;
918 	unsigned long flags;
919 	__u8 oldlines;
920 	int linechange = 0;
921 
922 	dbg("%s - port %d", __FUNCTION__, port->number);
923 
924 	tty = port->tty;
925 	if ((!tty) || (!tty->termios)) {
926 		dbg("%s - no tty structures", __FUNCTION__);
927 		return;
928 	}
929 
930 	spin_lock_irqsave(&priv->lock, flags);
931 	if (!priv->termios_initialized) {
932 		if (priv->chiptype == CT_EARTHMATE) {
933 			*(tty->termios) = tty_std_termios;
934 			tty->termios->c_cflag = B4800 | CS8 | CREAD | HUPCL | CLOCAL;
935 		} else if (priv->chiptype == CT_CYPHIDCOM) {
936 			*(tty->termios) = tty_std_termios;
937 			tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
938 		}
939 		priv->termios_initialized = 1;
940 	}
941 	spin_unlock_irqrestore(&priv->lock, flags);
942 
943 	cflag = tty->termios->c_cflag;
944 	iflag = tty->termios->c_iflag;
945 
946 	/* check if there are new settings */
947 	if (old_termios) {
948 		if ((cflag != old_termios->c_cflag) ||
949 		    (RELEVANT_IFLAG(iflag) != RELEVANT_IFLAG(old_termios->c_iflag))) {
950 			dbg("%s - attempting to set new termios settings", __FUNCTION__);
951 			/* should make a copy of this in case something goes wrong in the function, we can restore it */
952 			spin_lock_irqsave(&priv->lock, flags);
953 			priv->tmp_termios = *(tty->termios);
954 			spin_unlock_irqrestore(&priv->lock, flags);
955 		} else {
956 			dbg("%s - nothing to do, exiting", __FUNCTION__);
957 			return;
958 		}
959 	} else
960 		return;
961 
962 	/* set number of data bits, parity, stop bits */
963 	/* when parity is disabled the parity type bit is ignored */
964 
965 	stop_bits = cflag & CSTOPB ? 1 : 0; /* 1 means 2 stop bits, 0 means 1 stop bit */
966 
967 	if (cflag & PARENB) {
968 		parity_enable = 1;
969 		parity_type = cflag & PARODD ? 1 : 0; /* 1 means odd parity, 0 means even parity */
970 	} else
971 		parity_enable = parity_type = 0;
972 
973 	if (cflag & CSIZE) {
974 		switch (cflag & CSIZE) {
975 			case CS5: data_bits = 0; break;
976 			case CS6: data_bits = 1; break;
977 			case CS7: data_bits = 2; break;
978 			case CS8: data_bits = 3; break;
979 			default: err("%s - CSIZE was set, but not CS5-CS8", __FUNCTION__); data_bits = 3;
980 		}
981 	} else
982 		data_bits = 3;
983 
984 	spin_lock_irqsave(&priv->lock, flags);
985 	oldlines = priv->line_control;
986 	if ((cflag & CBAUD) == B0) {
987 		/* drop dtr and rts */
988 		dbg("%s - dropping the lines, baud rate 0bps", __FUNCTION__);
989 		baud_mask = B0;
990 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
991 	} else {
992 		baud_mask = (cflag & CBAUD);
993 		switch(baud_mask) {
994 			case B300: dbg("%s - setting baud 300bps", __FUNCTION__); break;
995 			case B600: dbg("%s - setting baud 600bps", __FUNCTION__); break;
996 			case B1200: dbg("%s - setting baud 1200bps", __FUNCTION__); break;
997 			case B2400: dbg("%s - setting baud 2400bps", __FUNCTION__); break;
998 			case B4800: dbg("%s - setting baud 4800bps", __FUNCTION__); break;
999 			case B9600: dbg("%s - setting baud 9600bps", __FUNCTION__); break;
1000 			case B19200: dbg("%s - setting baud 19200bps", __FUNCTION__); break;
1001 			case B38400: dbg("%s - setting baud 38400bps", __FUNCTION__); break;
1002 			case B57600: dbg("%s - setting baud 57600bps", __FUNCTION__); break;
1003 			case B115200: dbg("%s - setting baud 115200bps", __FUNCTION__); break;
1004 			default: dbg("%s - unknown masked baud rate", __FUNCTION__);
1005 		}
1006 		priv->line_control = (CONTROL_DTR | CONTROL_RTS);
1007 	}
1008 	spin_unlock_irqrestore(&priv->lock, flags);
1009 
1010 	dbg("%s - sending %d stop_bits, %d parity_enable, %d parity_type, %d data_bits (+5)", __FUNCTION__,
1011 	    stop_bits, parity_enable, parity_type, data_bits);
1012 
1013 	cypress_serial_control(port, baud_mask, data_bits, stop_bits, parity_enable,
1014 			       parity_type, 0, CYPRESS_SET_CONFIG);
1015 
1016 	/* we perform a CYPRESS_GET_CONFIG so that the current settings are filled into the private structure
1017          * this should confirm that all is working if it returns what we just set */
1018 	cypress_serial_control(port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
1019 
1020 	/* Here we can define custom tty settings for devices
1021          *
1022          * the main tty termios flag base comes from empeg.c
1023          */
1024 
1025 	spin_lock_irqsave(&priv->lock, flags);
1026 	if ( (priv->chiptype == CT_EARTHMATE) && (priv->baud_rate == 4800) ) {
1027 
1028 		dbg("Using custom termios settings for a baud rate of 4800bps.");
1029 		/* define custom termios settings for NMEA protocol */
1030 
1031 		tty->termios->c_iflag /* input modes - */
1032 			&= ~(IGNBRK		/* disable ignore break */
1033 			| BRKINT		/* disable break causes interrupt */
1034 			| PARMRK		/* disable mark parity errors */
1035 			| ISTRIP		/* disable clear high bit of input characters */
1036 			| INLCR			/* disable translate NL to CR */
1037 			| IGNCR			/* disable ignore CR */
1038 			| ICRNL			/* disable translate CR to NL */
1039 			| IXON);		/* disable enable XON/XOFF flow control */
1040 
1041 		tty->termios->c_oflag /* output modes */
1042 			&= ~OPOST;		/* disable postprocess output characters */
1043 
1044 		tty->termios->c_lflag /* line discipline modes */
1045 			&= ~(ECHO 		/* disable echo input characters */
1046 			| ECHONL		/* disable echo new line */
1047 			| ICANON		/* disable erase, kill, werase, and rprnt special characters */
1048 			| ISIG			/* disable interrupt, quit, and suspend special characters */
1049 			| IEXTEN);		/* disable non-POSIX special characters */
1050 
1051 	} /* CT_CYPHIDCOM: Application should handle this for device */
1052 
1053 	linechange = (priv->line_control != oldlines);
1054 	spin_unlock_irqrestore(&priv->lock, flags);
1055 
1056 	/* if necessary, set lines */
1057 	if (linechange) {
1058 		priv->cmd_ctrl = 1;
1059 		cypress_write(port, NULL, 0);
1060 	}
1061 } /* cypress_set_termios */
1062 
1063 
1064 /* returns amount of data still left in soft buffer */
1065 static int cypress_chars_in_buffer(struct usb_serial_port *port)
1066 {
1067 	struct cypress_private *priv = usb_get_serial_port_data(port);
1068 	int chars = 0;
1069 	unsigned long flags;
1070 
1071 	dbg("%s - port %d", __FUNCTION__, port->number);
1072 
1073 	spin_lock_irqsave(&priv->lock, flags);
1074 	chars = cypress_buf_data_avail(priv->buf);
1075 	spin_unlock_irqrestore(&priv->lock, flags);
1076 
1077 	dbg("%s - returns %d", __FUNCTION__, chars);
1078 	return chars;
1079 }
1080 
1081 
1082 static void cypress_throttle (struct usb_serial_port *port)
1083 {
1084 	struct cypress_private *priv = usb_get_serial_port_data(port);
1085 	unsigned long flags;
1086 
1087 	dbg("%s - port %d", __FUNCTION__, port->number);
1088 
1089 	spin_lock_irqsave(&priv->lock, flags);
1090 	priv->rx_flags = THROTTLED;
1091 	spin_unlock_irqrestore(&priv->lock, flags);
1092 }
1093 
1094 
1095 static void cypress_unthrottle (struct usb_serial_port *port)
1096 {
1097 	struct cypress_private *priv = usb_get_serial_port_data(port);
1098 	int actually_throttled, result;
1099 	unsigned long flags;
1100 
1101 	dbg("%s - port %d", __FUNCTION__, port->number);
1102 
1103 	spin_lock_irqsave(&priv->lock, flags);
1104 	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
1105 	priv->rx_flags = 0;
1106 	spin_unlock_irqrestore(&priv->lock, flags);
1107 
1108 	if (actually_throttled) {
1109 		port->interrupt_in_urb->dev = port->serial->dev;
1110 
1111 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1112 		if (result)
1113 			dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
1114 	}
1115 }
1116 
1117 
1118 static void cypress_read_int_callback(struct urb *urb, struct pt_regs *regs)
1119 {
1120 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
1121 	struct cypress_private *priv = usb_get_serial_port_data(port);
1122 	struct tty_struct *tty;
1123 	unsigned char *data = urb->transfer_buffer;
1124 	unsigned long flags;
1125 	char tty_flag = TTY_NORMAL;
1126 	int havedata = 0;
1127 	int bytes = 0;
1128 	int result;
1129 	int i = 0;
1130 
1131 	dbg("%s - port %d", __FUNCTION__, port->number);
1132 
1133 	if (urb->status) {
1134 		dbg("%s - nonzero read status received: %d", __FUNCTION__, urb->status);
1135 		return;
1136 	}
1137 
1138 	spin_lock_irqsave(&priv->lock, flags);
1139 	if (priv->rx_flags & THROTTLED) {
1140 		dbg("%s - now throttling", __FUNCTION__);
1141 		priv->rx_flags |= ACTUALLY_THROTTLED;
1142 		spin_unlock_irqrestore(&priv->lock, flags);
1143 		return;
1144 	}
1145 	spin_unlock_irqrestore(&priv->lock, flags);
1146 
1147 	tty = port->tty;
1148 	if (!tty) {
1149 		dbg("%s - bad tty pointer - exiting", __FUNCTION__);
1150 		return;
1151 	}
1152 
1153 	spin_lock_irqsave(&priv->lock, flags);
1154 	switch(urb->actual_length) {
1155 		case 32:
1156 			/* This is for the CY7C64013... */
1157 			priv->current_status = data[0] & 0xF8;
1158 			bytes = data[1]+2;
1159 			i=2;
1160 			if (bytes > 2)
1161 				havedata = 1;
1162 			break;
1163 		case 8:
1164 			/* This is for the CY7C63743... */
1165 			priv->current_status = data[0] & 0xF8;
1166 			bytes = (data[0] & 0x07)+1;
1167 			i=1;
1168 			if (bytes > 1)
1169 				havedata = 1;
1170 			break;
1171 		default:
1172 			dbg("%s - wrong packet size - received %d bytes", __FUNCTION__, urb->actual_length);
1173 			spin_unlock_irqrestore(&priv->lock, flags);
1174 			goto continue_read;
1175 	}
1176 	spin_unlock_irqrestore(&priv->lock, flags);
1177 
1178 	usb_serial_debug_data (debug, &port->dev, __FUNCTION__, urb->actual_length, data);
1179 
1180 	spin_lock_irqsave(&priv->lock, flags);
1181 	/* check to see if status has changed */
1182 	if (priv != NULL) {
1183 		if (priv->current_status != priv->prev_status) {
1184 			priv->diff_status |= priv->current_status ^ priv->prev_status;
1185 			wake_up_interruptible(&priv->delta_msr_wait);
1186 			priv->prev_status = priv->current_status;
1187 		}
1188 	}
1189 	spin_unlock_irqrestore(&priv->lock, flags);
1190 
1191 	/* hangup, as defined in acm.c... this might be a bad place for it though */
1192 	if (tty && !(tty->termios->c_cflag & CLOCAL) && !(priv->current_status & UART_CD)) {
1193 		dbg("%s - calling hangup", __FUNCTION__);
1194 		tty_hangup(tty);
1195 		goto continue_read;
1196 	}
1197 
1198 	/* There is one error bit... I'm assuming it is a parity error indicator
1199 	 * as the generic firmware will set this bit to 1 if a parity error occurs.
1200 	 * I can not find reference to any other error events.
1201 	 *
1202 	 */
1203 	spin_lock_irqsave(&priv->lock, flags);
1204 	if (priv->current_status & CYP_ERROR) {
1205 		spin_unlock_irqrestore(&priv->lock, flags);
1206 		tty_flag = TTY_PARITY;
1207 		dbg("%s - Parity Error detected", __FUNCTION__);
1208 	} else
1209 		spin_unlock_irqrestore(&priv->lock, flags);
1210 
1211 	/* process read if there is data other than line status */
1212 	if (tty && (bytes > i)) {
1213 		for (; i < bytes ; ++i) {
1214 			dbg("pushing byte number %d - %d - %c",i,data[i],data[i]);
1215 			if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
1216 				tty_flip_buffer_push(tty);
1217 			}
1218 			tty_insert_flip_char(tty, data[i], tty_flag);
1219 		}
1220 		tty_flip_buffer_push(port->tty);
1221 	}
1222 
1223 	spin_lock_irqsave(&priv->lock, flags);
1224 	priv->bytes_in += bytes;  /* control and status byte(s) are also counted */
1225 	spin_unlock_irqrestore(&priv->lock, flags);
1226 
1227 continue_read:
1228 
1229 	/* Continue trying to always read... unless the port has closed.  */
1230 
1231 	if (port->open_count > 0) {
1232 	usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1233 		usb_rcvintpipe(port->serial->dev, port->interrupt_in_endpointAddress),
1234 		port->interrupt_in_urb->transfer_buffer,
1235 		port->interrupt_in_urb->transfer_buffer_length,
1236 		cypress_read_int_callback, port,
1237 		interval);
1238 	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1239 	if (result)
1240 		dev_err(&urb->dev->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
1241 	}
1242 
1243 	return;
1244 } /* cypress_read_int_callback */
1245 
1246 
1247 static void cypress_write_int_callback(struct urb *urb, struct pt_regs *regs)
1248 {
1249 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
1250 	struct cypress_private *priv = usb_get_serial_port_data(port);
1251 	int result;
1252 
1253 	dbg("%s - port %d", __FUNCTION__, port->number);
1254 
1255 	switch (urb->status) {
1256 		case 0:
1257 			/* success */
1258 			break;
1259 		case -ECONNRESET:
1260 		case -ENOENT:
1261 		case -ESHUTDOWN:
1262 			/* this urb is terminated, clean up */
1263 			dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
1264 			priv->write_urb_in_use = 0;
1265 			return;
1266 		case -EPIPE: /* no break needed */
1267 			usb_clear_halt(port->serial->dev, 0x02);
1268 		default:
1269 			/* error in the urb, so we have to resubmit it */
1270 			dbg("%s - Overflow in write", __FUNCTION__);
1271 			dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
1272 			port->interrupt_out_urb->transfer_buffer_length = 1;
1273 			port->interrupt_out_urb->dev = port->serial->dev;
1274 			result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
1275 			if (result)
1276 				dev_err(&urb->dev->dev, "%s - failed resubmitting write urb, error %d\n",
1277 					__FUNCTION__, result);
1278 			else
1279 				return;
1280 	}
1281 
1282 	priv->write_urb_in_use = 0;
1283 
1284 	/* send any buffered data */
1285 	cypress_send(port);
1286 }
1287 
1288 
1289 /*****************************************************************************
1290  * Write buffer functions - buffering code from pl2303 used
1291  *****************************************************************************/
1292 
1293 /*
1294  * cypress_buf_alloc
1295  *
1296  * Allocate a circular buffer and all associated memory.
1297  */
1298 
1299 static struct cypress_buf *cypress_buf_alloc(unsigned int size)
1300 {
1301 
1302 	struct cypress_buf *cb;
1303 
1304 
1305 	if (size == 0)
1306 		return NULL;
1307 
1308 	cb = (struct cypress_buf *)kmalloc(sizeof(struct cypress_buf), GFP_KERNEL);
1309 	if (cb == NULL)
1310 		return NULL;
1311 
1312 	cb->buf_buf = kmalloc(size, GFP_KERNEL);
1313 	if (cb->buf_buf == NULL) {
1314 		kfree(cb);
1315 		return NULL;
1316 	}
1317 
1318 	cb->buf_size = size;
1319 	cb->buf_get = cb->buf_put = cb->buf_buf;
1320 
1321 	return cb;
1322 
1323 }
1324 
1325 
1326 /*
1327  * cypress_buf_free
1328  *
1329  * Free the buffer and all associated memory.
1330  */
1331 
1332 static void cypress_buf_free(struct cypress_buf *cb)
1333 {
1334 	if (cb) {
1335 		kfree(cb->buf_buf);
1336 		kfree(cb);
1337 	}
1338 }
1339 
1340 
1341 /*
1342  * cypress_buf_clear
1343  *
1344  * Clear out all data in the circular buffer.
1345  */
1346 
1347 static void cypress_buf_clear(struct cypress_buf *cb)
1348 {
1349 	if (cb != NULL)
1350 		cb->buf_get = cb->buf_put;
1351 		/* equivalent to a get of all data available */
1352 }
1353 
1354 
1355 /*
1356  * cypress_buf_data_avail
1357  *
1358  * Return the number of bytes of data available in the circular
1359  * buffer.
1360  */
1361 
1362 static unsigned int cypress_buf_data_avail(struct cypress_buf *cb)
1363 {
1364 	if (cb != NULL)
1365 		return ((cb->buf_size + cb->buf_put - cb->buf_get) % cb->buf_size);
1366 	else
1367 		return 0;
1368 }
1369 
1370 
1371 /*
1372  * cypress_buf_space_avail
1373  *
1374  * Return the number of bytes of space available in the circular
1375  * buffer.
1376  */
1377 
1378 static unsigned int cypress_buf_space_avail(struct cypress_buf *cb)
1379 {
1380 	if (cb != NULL)
1381 		return ((cb->buf_size + cb->buf_get - cb->buf_put - 1) % cb->buf_size);
1382 	else
1383 		return 0;
1384 }
1385 
1386 
1387 /*
1388  * cypress_buf_put
1389  *
1390  * Copy data data from a user buffer and put it into the circular buffer.
1391  * Restrict to the amount of space available.
1392  *
1393  * Return the number of bytes copied.
1394  */
1395 
1396 static unsigned int cypress_buf_put(struct cypress_buf *cb, const char *buf,
1397 	unsigned int count)
1398 {
1399 
1400 	unsigned int len;
1401 
1402 
1403 	if (cb == NULL)
1404 		return 0;
1405 
1406 	len  = cypress_buf_space_avail(cb);
1407 	if (count > len)
1408 		count = len;
1409 
1410 	if (count == 0)
1411 		return 0;
1412 
1413 	len = cb->buf_buf + cb->buf_size - cb->buf_put;
1414 	if (count > len) {
1415 		memcpy(cb->buf_put, buf, len);
1416 		memcpy(cb->buf_buf, buf+len, count - len);
1417 		cb->buf_put = cb->buf_buf + count - len;
1418 	} else {
1419 		memcpy(cb->buf_put, buf, count);
1420 		if (count < len)
1421 			cb->buf_put += count;
1422 		else /* count == len */
1423 			cb->buf_put = cb->buf_buf;
1424 	}
1425 
1426 	return count;
1427 
1428 }
1429 
1430 
1431 /*
1432  * cypress_buf_get
1433  *
1434  * Get data from the circular buffer and copy to the given buffer.
1435  * Restrict to the amount of data available.
1436  *
1437  * Return the number of bytes copied.
1438  */
1439 
1440 static unsigned int cypress_buf_get(struct cypress_buf *cb, char *buf,
1441 	unsigned int count)
1442 {
1443 
1444 	unsigned int len;
1445 
1446 
1447 	if (cb == NULL)
1448 		return 0;
1449 
1450 	len = cypress_buf_data_avail(cb);
1451 	if (count > len)
1452 		count = len;
1453 
1454 	if (count == 0)
1455 		return 0;
1456 
1457 	len = cb->buf_buf + cb->buf_size - cb->buf_get;
1458 	if (count > len) {
1459 		memcpy(buf, cb->buf_get, len);
1460 		memcpy(buf+len, cb->buf_buf, count - len);
1461 		cb->buf_get = cb->buf_buf + count - len;
1462 	} else {
1463 		memcpy(buf, cb->buf_get, count);
1464 		if (count < len)
1465 			cb->buf_get += count;
1466 		else /* count == len */
1467 			cb->buf_get = cb->buf_buf;
1468 	}
1469 
1470 	return count;
1471 
1472 }
1473 
1474 /*****************************************************************************
1475  * Module functions
1476  *****************************************************************************/
1477 
1478 static int __init cypress_init(void)
1479 {
1480 	int retval;
1481 
1482 	dbg("%s", __FUNCTION__);
1483 
1484 	retval = usb_serial_register(&cypress_earthmate_device);
1485 	if (retval)
1486 		goto failed_em_register;
1487 	retval = usb_serial_register(&cypress_hidcom_device);
1488 	if (retval)
1489 		goto failed_hidcom_register;
1490 	retval = usb_register(&cypress_driver);
1491 	if (retval)
1492 		goto failed_usb_register;
1493 
1494 	info(DRIVER_DESC " " DRIVER_VERSION);
1495 	return 0;
1496 failed_usb_register:
1497 	usb_deregister(&cypress_driver);
1498 failed_hidcom_register:
1499 	usb_serial_deregister(&cypress_hidcom_device);
1500 failed_em_register:
1501 	usb_serial_deregister(&cypress_earthmate_device);
1502 
1503 	return retval;
1504 }
1505 
1506 
1507 static void __exit cypress_exit (void)
1508 {
1509 	dbg("%s", __FUNCTION__);
1510 
1511 	usb_deregister (&cypress_driver);
1512 	usb_serial_deregister (&cypress_earthmate_device);
1513 	usb_serial_deregister (&cypress_hidcom_device);
1514 }
1515 
1516 
1517 module_init(cypress_init);
1518 module_exit(cypress_exit);
1519 
1520 MODULE_AUTHOR( DRIVER_AUTHOR );
1521 MODULE_DESCRIPTION( DRIVER_DESC );
1522 MODULE_VERSION( DRIVER_VERSION );
1523 MODULE_LICENSE("GPL");
1524 
1525 module_param(debug, bool, S_IRUGO | S_IWUSR);
1526 MODULE_PARM_DESC(debug, "Debug enabled or not");
1527 module_param(stats, bool, S_IRUGO | S_IWUSR);
1528 MODULE_PARM_DESC(stats, "Enable statistics or not");
1529 module_param(interval, int, S_IRUGO | S_IWUSR);
1530 MODULE_PARM_DESC(interval, "Overrides interrupt interval");
1531