xref: /openbmc/linux/drivers/usb/serial/cypress_m8.c (revision 545e4006)
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
15  * driver
16  *
17  * See http://geocities.com/i0xox0i for information on this driver and the
18  * earthmate usb device.
19  *
20  *  Lonnie Mendez <dignome@gmail.com>
21  *  4-29-2005
22  *	Fixed problem where setting or retreiving the serial config would fail
23  *	with EPIPE.  Removed CRTS toggling so the driver behaves more like
24  *	other usbserial adapters.  Issued new interval of 1ms instead of the
25  *	default 10ms.  As a result, transfer speed has been substantially
26  *	increased from avg. 850bps to avg. 3300bps.  initial termios has also
27  *	been modified.  Cleaned up code and formatting issues so it is more
28  *	readable.  Replaced the C++ style comments.
29  *
30  *  Lonnie Mendez <dignome@gmail.com>
31  *  12-15-2004
32  *	Incorporated write buffering from pl2303 driver.  Fixed bug with line
33  *	handling so both lines are raised in cypress_open. (was dropping rts)
34  *      Various code cleanups made as well along with other misc bug fixes.
35  *
36  *  Lonnie Mendez <dignome@gmail.com>
37  *  04-10-2004
38  *	Driver modified to support dynamic line settings.  Various improvments
39  *      and features.
40  *
41  *  Neil Whelchel
42  *  10-2003
43  *	Driver first released.
44  *
45  */
46 
47 /* Thanks to Neil Whelchel for writing the first cypress m8 implementation
48    for linux. */
49 /* Thanks to cypress for providing references for the hid reports. */
50 /* Thanks to Jiang Zhang for providing links and for general help. */
51 /* Code originates and was built up from ftdi_sio, belkin, pl2303 and others.*/
52 
53 
54 #include <linux/kernel.h>
55 #include <linux/errno.h>
56 #include <linux/init.h>
57 #include <linux/slab.h>
58 #include <linux/tty.h>
59 #include <linux/tty_driver.h>
60 #include <linux/tty_flip.h>
61 #include <linux/module.h>
62 #include <linux/moduleparam.h>
63 #include <linux/spinlock.h>
64 #include <linux/usb.h>
65 #include <linux/usb/serial.h>
66 #include <linux/serial.h>
67 #include <linux/delay.h>
68 #include <linux/uaccess.h>
69 
70 #include "cypress_m8.h"
71 
72 
73 #ifdef CONFIG_USB_SERIAL_DEBUG
74 	static int debug = 1;
75 #else
76 	static int debug;
77 #endif
78 static int stats;
79 static int interval;
80 
81 /*
82  * Version Information
83  */
84 #define DRIVER_VERSION "v1.09"
85 #define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"
86 #define DRIVER_DESC "Cypress USB to Serial Driver"
87 
88 /* write buffer size defines */
89 #define CYPRESS_BUF_SIZE	1024
90 #define CYPRESS_CLOSING_WAIT	(30*HZ)
91 
92 static struct usb_device_id id_table_earthmate [] = {
93 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
94 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
95 	{ }						/* Terminating entry */
96 };
97 
98 static struct usb_device_id id_table_cyphidcomrs232 [] = {
99 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
100 	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
101 	{ }						/* Terminating entry */
102 };
103 
104 static struct usb_device_id id_table_nokiaca42v2 [] = {
105 	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
106 	{ }						/* Terminating entry */
107 };
108 
109 static struct usb_device_id id_table_combined [] = {
110 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB) },
111 	{ USB_DEVICE(VENDOR_ID_DELORME, PRODUCT_ID_EARTHMATEUSB_LT20) },
112 	{ USB_DEVICE(VENDOR_ID_CYPRESS, PRODUCT_ID_CYPHIDCOM) },
113 	{ USB_DEVICE(VENDOR_ID_POWERCOM, PRODUCT_ID_UPS) },
114 	{ USB_DEVICE(VENDOR_ID_DAZZLE, PRODUCT_ID_CA42) },
115 	{ }						/* Terminating entry */
116 };
117 
118 MODULE_DEVICE_TABLE(usb, id_table_combined);
119 
120 static struct usb_driver cypress_driver = {
121 	.name =		"cypress",
122 	.probe =	usb_serial_probe,
123 	.disconnect =	usb_serial_disconnect,
124 	.id_table =	id_table_combined,
125 	.no_dynamic_id = 	1,
126 };
127 
128 enum packet_format {
129 	packet_format_1,  /* b0:status, b1:payload count */
130 	packet_format_2   /* b0[7:3]:status, b0[2:0]:payload count */
131 };
132 
133 struct cypress_private {
134 	spinlock_t lock;		   /* private lock */
135 	int chiptype;			   /* identifier of device, for quirks/etc */
136 	int bytes_in;			   /* used for statistics */
137 	int bytes_out;			   /* used for statistics */
138 	int cmd_count;			   /* used for statistics */
139 	int cmd_ctrl;			   /* always set this to 1 before issuing a command */
140 	struct cypress_buf *buf;	   /* write buffer */
141 	int write_urb_in_use;		   /* write urb in use indicator */
142 	int write_urb_interval;            /* interval to use for write urb */
143 	int read_urb_interval;             /* interval to use for read urb */
144 	int comm_is_ok;                    /* true if communication is (still) ok */
145 	int termios_initialized;
146 	__u8 line_control;	   	   /* holds dtr / rts value */
147 	__u8 current_status;	   	   /* received from last read - info on dsr,cts,cd,ri,etc */
148 	__u8 current_config;	   	   /* stores the current configuration byte */
149 	__u8 rx_flags;			   /* throttling - used from whiteheat/ftdi_sio */
150 	enum packet_format pkt_fmt;	   /* format to use for packet send / receive */
151 	int get_cfg_unsafe;		   /* If true, the CYPRESS_GET_CONFIG is unsafe */
152 	int baud_rate;			   /* stores current baud rate in
153 					      integer form */
154 	int isthrottled;		   /* if throttled, discard reads */
155 	wait_queue_head_t delta_msr_wait;  /* used for TIOCMIWAIT */
156 	char prev_status, diff_status;	   /* used for TIOCMIWAIT */
157 	/* we pass a pointer to this as the arguement sent to
158 	   cypress_set_termios old_termios */
159 	struct ktermios tmp_termios; 	   /* stores the old termios settings */
160 };
161 
162 /* write buffer structure */
163 struct cypress_buf {
164 	unsigned int	buf_size;
165 	char		*buf_buf;
166 	char		*buf_get;
167 	char		*buf_put;
168 };
169 
170 /* function prototypes for the Cypress USB to serial device */
171 static int  cypress_earthmate_startup(struct usb_serial *serial);
172 static int  cypress_hidcom_startup(struct usb_serial *serial);
173 static int  cypress_ca42v2_startup(struct usb_serial *serial);
174 static void cypress_shutdown(struct usb_serial *serial);
175 static int  cypress_open(struct tty_struct *tty,
176 			struct usb_serial_port *port, struct file *filp);
177 static void cypress_close(struct tty_struct *tty,
178 			struct usb_serial_port *port, struct file *filp);
179 static int  cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
180 			const unsigned char *buf, int count);
181 static void cypress_send(struct usb_serial_port *port);
182 static int  cypress_write_room(struct tty_struct *tty);
183 static int  cypress_ioctl(struct tty_struct *tty, struct file *file,
184 			unsigned int cmd, unsigned long arg);
185 static void cypress_set_termios(struct tty_struct *tty,
186 			struct usb_serial_port *port, struct ktermios *old);
187 static int  cypress_tiocmget(struct tty_struct *tty, struct file *file);
188 static int  cypress_tiocmset(struct tty_struct *tty, struct file *file,
189 			unsigned int set, unsigned int clear);
190 static int  cypress_chars_in_buffer(struct tty_struct *tty);
191 static void cypress_throttle(struct tty_struct *tty);
192 static void cypress_unthrottle(struct tty_struct *tty);
193 static void cypress_set_dead(struct usb_serial_port *port);
194 static void cypress_read_int_callback(struct urb *urb);
195 static void cypress_write_int_callback(struct urb *urb);
196 /* write buffer functions */
197 static struct cypress_buf *cypress_buf_alloc(unsigned int size);
198 static void cypress_buf_free(struct cypress_buf *cb);
199 static void cypress_buf_clear(struct cypress_buf *cb);
200 static unsigned int cypress_buf_data_avail(struct cypress_buf *cb);
201 static unsigned int cypress_buf_space_avail(struct cypress_buf *cb);
202 static unsigned int cypress_buf_put(struct cypress_buf *cb,
203 					const char *buf, unsigned int count);
204 static unsigned int cypress_buf_get(struct cypress_buf *cb,
205 					char *buf, unsigned int count);
206 
207 
208 static struct usb_serial_driver cypress_earthmate_device = {
209 	.driver = {
210 		.owner =		THIS_MODULE,
211 		.name =			"earthmate",
212 	},
213 	.description =			"DeLorme Earthmate USB",
214 	.usb_driver = 			&cypress_driver,
215 	.id_table =			id_table_earthmate,
216 	.num_ports =			1,
217 	.attach =			cypress_earthmate_startup,
218 	.shutdown =			cypress_shutdown,
219 	.open =				cypress_open,
220 	.close =			cypress_close,
221 	.write =			cypress_write,
222 	.write_room =			cypress_write_room,
223 	.ioctl =			cypress_ioctl,
224 	.set_termios =			cypress_set_termios,
225 	.tiocmget =			cypress_tiocmget,
226 	.tiocmset =			cypress_tiocmset,
227 	.chars_in_buffer =		cypress_chars_in_buffer,
228 	.throttle =		 	cypress_throttle,
229 	.unthrottle =			cypress_unthrottle,
230 	.read_int_callback =		cypress_read_int_callback,
231 	.write_int_callback =		cypress_write_int_callback,
232 };
233 
234 static struct usb_serial_driver cypress_hidcom_device = {
235 	.driver = {
236 		.owner =		THIS_MODULE,
237 		.name =			"cyphidcom",
238 	},
239 	.description =			"HID->COM RS232 Adapter",
240 	.usb_driver = 			&cypress_driver,
241 	.id_table =			id_table_cyphidcomrs232,
242 	.num_ports =			1,
243 	.attach =			cypress_hidcom_startup,
244 	.shutdown =			cypress_shutdown,
245 	.open =				cypress_open,
246 	.close =			cypress_close,
247 	.write =			cypress_write,
248 	.write_room =			cypress_write_room,
249 	.ioctl =			cypress_ioctl,
250 	.set_termios =			cypress_set_termios,
251 	.tiocmget =			cypress_tiocmget,
252 	.tiocmset =			cypress_tiocmset,
253 	.chars_in_buffer =		cypress_chars_in_buffer,
254 	.throttle =			cypress_throttle,
255 	.unthrottle =			cypress_unthrottle,
256 	.read_int_callback =		cypress_read_int_callback,
257 	.write_int_callback =		cypress_write_int_callback,
258 };
259 
260 static struct usb_serial_driver cypress_ca42v2_device = {
261 	.driver = {
262 		.owner =		THIS_MODULE,
263 		.name =			"nokiaca42v2",
264 	},
265 	.description =			"Nokia CA-42 V2 Adapter",
266 	.usb_driver = 			&cypress_driver,
267 	.id_table =			id_table_nokiaca42v2,
268 	.num_ports =			1,
269 	.attach =			cypress_ca42v2_startup,
270 	.shutdown =			cypress_shutdown,
271 	.open =				cypress_open,
272 	.close =			cypress_close,
273 	.write =			cypress_write,
274 	.write_room =			cypress_write_room,
275 	.ioctl =			cypress_ioctl,
276 	.set_termios =			cypress_set_termios,
277 	.tiocmget =			cypress_tiocmget,
278 	.tiocmset =			cypress_tiocmset,
279 	.chars_in_buffer =		cypress_chars_in_buffer,
280 	.throttle =			cypress_throttle,
281 	.unthrottle =			cypress_unthrottle,
282 	.read_int_callback =		cypress_read_int_callback,
283 	.write_int_callback =		cypress_write_int_callback,
284 };
285 
286 /*****************************************************************************
287  * Cypress serial helper functions
288  *****************************************************************************/
289 
290 
291 static int analyze_baud_rate(struct usb_serial_port *port, speed_t new_rate)
292 {
293 	struct cypress_private *priv;
294 	priv = usb_get_serial_port_data(port);
295 
296 	/*
297 	 * The general purpose firmware for the Cypress M8 allows for
298 	 * a maximum speed of 57600bps (I have no idea whether DeLorme
299 	 * chose to use the general purpose firmware or not), if you
300 	 * need to modify this speed setting for your own project
301 	 * please add your own chiptype and modify the code likewise.
302 	 * The Cypress HID->COM device will work successfully up to
303 	 * 115200bps (but the actual throughput is around 3kBps).
304 	 */
305 	if (port->serial->dev->speed == USB_SPEED_LOW) {
306 		/*
307 		 * Mike Isely <isely@pobox.com> 2-Feb-2008: The
308 		 * Cypress app note that describes this mechanism
309 		 * states the the low-speed part can't handle more
310 		 * than 800 bytes/sec, in which case 4800 baud is the
311 		 * safest speed for a part like that.
312 		 */
313 		if (new_rate > 4800) {
314 			dbg("%s - failed setting baud rate, device incapable "
315 			    "speed %d", __func__, new_rate);
316 			return -1;
317 		}
318 	}
319 	switch (priv->chiptype) {
320 	case CT_EARTHMATE:
321 		if (new_rate <= 600) {
322 			/* 300 and 600 baud rates are supported under
323 			 * the generic firmware, but are not used with
324 			 * NMEA and SiRF protocols */
325 			dbg("%s - failed setting baud rate, unsupported speed "
326 			    "of %d on Earthmate GPS", __func__, new_rate);
327 			return -1;
328 		}
329 		break;
330 	default:
331 		break;
332 	}
333 	return new_rate;
334 }
335 
336 
337 /* This function can either set or retrieve the current serial line settings */
338 static int cypress_serial_control(struct tty_struct *tty,
339 	struct usb_serial_port *port, speed_t baud_rate, int data_bits,
340 	int stop_bits, int parity_enable, int parity_type, int reset,
341 	int cypress_request_type)
342 {
343 	int new_baudrate = 0, retval = 0, tries = 0;
344 	struct cypress_private *priv;
345 	__u8 feature_buffer[5];
346 	unsigned long flags;
347 
348 	dbg("%s", __func__);
349 
350 	priv = usb_get_serial_port_data(port);
351 
352 	if (!priv->comm_is_ok)
353 		return -ENODEV;
354 
355 	switch (cypress_request_type) {
356 	case CYPRESS_SET_CONFIG:
357 		new_baudrate = priv->baud_rate;
358 		/* 0 means 'Hang up' so doesn't change the true bit rate */
359 		if (baud_rate == 0)
360 			new_baudrate = priv->baud_rate;
361 		/* Change of speed ? */
362 		else if (baud_rate != priv->baud_rate) {
363 			dbg("%s - baud rate is changing", __func__);
364 			retval = analyze_baud_rate(port, baud_rate);
365 			if (retval >=  0) {
366 				new_baudrate = retval;
367 				dbg("%s - New baud rate set to %d",
368 				    __func__, new_baudrate);
369 			}
370 		}
371 		dbg("%s - baud rate is being sent as %d",
372 					__func__, new_baudrate);
373 
374 		memset(feature_buffer, 0, sizeof(feature_buffer));
375 		/* fill the feature_buffer with new configuration */
376 		*((u_int32_t *)feature_buffer) = new_baudrate;
377 		feature_buffer[4] |= data_bits;   /* assign data bits in 2 bit space ( max 3 ) */
378 		/* 1 bit gap */
379 		feature_buffer[4] |= (stop_bits << 3);   /* assign stop bits in 1 bit space */
380 		feature_buffer[4] |= (parity_enable << 4);   /* assign parity flag in 1 bit space */
381 		feature_buffer[4] |= (parity_type << 5);   /* assign parity type in 1 bit space */
382 		/* 1 bit gap */
383 		feature_buffer[4] |= (reset << 7);   /* assign reset at end of byte, 1 bit space */
384 
385 		dbg("%s - device is being sent this feature report:",
386 								__func__);
387 		dbg("%s - %02X - %02X - %02X - %02X - %02X", __func__,
388 			feature_buffer[0], feature_buffer[1],
389 			feature_buffer[2], feature_buffer[3],
390 			feature_buffer[4]);
391 
392 		do {
393 			retval = usb_control_msg(port->serial->dev,
394 					usb_sndctrlpipe(port->serial->dev, 0),
395 					HID_REQ_SET_REPORT,
396 					USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
397 					0x0300, 0, feature_buffer,
398 					sizeof(feature_buffer), 500);
399 
400 			if (tries++ >= 3)
401 				break;
402 
403 		} while (retval != sizeof(feature_buffer) &&
404 			 retval != -ENODEV);
405 
406 		if (retval != sizeof(feature_buffer)) {
407 			err("%s - failed sending serial line settings - %d",
408 							__func__, retval);
409 			cypress_set_dead(port);
410 		} else {
411 			spin_lock_irqsave(&priv->lock, flags);
412 			priv->baud_rate = new_baudrate;
413 			priv->current_config = feature_buffer[4];
414 			spin_unlock_irqrestore(&priv->lock, flags);
415 			/* If we asked for a speed change encode it */
416 			if (baud_rate)
417 				tty_encode_baud_rate(tty,
418 					new_baudrate, new_baudrate);
419 		}
420 	break;
421 	case CYPRESS_GET_CONFIG:
422 		if (priv->get_cfg_unsafe) {
423 			/* Not implemented for this device,
424 			   and if we try to do it we're likely
425 			   to crash the hardware. */
426 			return -ENOTTY;
427 		}
428 		dbg("%s - retreiving serial line settings", __func__);
429 		/* set initial values in feature buffer */
430 		memset(feature_buffer, 0, sizeof(feature_buffer));
431 
432 		do {
433 			retval = usb_control_msg(port->serial->dev,
434 					usb_rcvctrlpipe(port->serial->dev, 0),
435 					HID_REQ_GET_REPORT,
436 					USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS,
437 					0x0300, 0, feature_buffer,
438 					sizeof(feature_buffer), 500);
439 
440 			if (tries++ >= 3)
441 				break;
442 		} while (retval != sizeof(feature_buffer)
443 						&& retval != -ENODEV);
444 
445 		if (retval != sizeof(feature_buffer)) {
446 			err("%s - failed to retrieve serial line settings - %d", __func__, retval);
447 			cypress_set_dead(port);
448 			return retval;
449 		} else {
450 			spin_lock_irqsave(&priv->lock, flags);
451 			/* store the config in one byte, and later
452 			   use bit masks to check values */
453 			priv->current_config = feature_buffer[4];
454 			priv->baud_rate = *((u_int32_t *)feature_buffer);
455 			spin_unlock_irqrestore(&priv->lock, flags);
456 		}
457 	}
458 	spin_lock_irqsave(&priv->lock, flags);
459 	++priv->cmd_count;
460 	spin_unlock_irqrestore(&priv->lock, flags);
461 
462 	return retval;
463 } /* cypress_serial_control */
464 
465 
466 static void cypress_set_dead(struct usb_serial_port *port)
467 {
468 	struct cypress_private *priv = usb_get_serial_port_data(port);
469 	unsigned long flags;
470 
471 	spin_lock_irqsave(&priv->lock, flags);
472 	if (!priv->comm_is_ok) {
473 		spin_unlock_irqrestore(&priv->lock, flags);
474 		return;
475 	}
476 	priv->comm_is_ok = 0;
477 	spin_unlock_irqrestore(&priv->lock, flags);
478 
479 	err("cypress_m8 suspending failing port %d - interval might be too short",
480 	    port->number);
481 }
482 
483 
484 /*****************************************************************************
485  * Cypress serial driver functions
486  *****************************************************************************/
487 
488 
489 static int generic_startup(struct usb_serial *serial)
490 {
491 	struct cypress_private *priv;
492 	struct usb_serial_port *port = serial->port[0];
493 
494 	dbg("%s - port %d", __func__, port->number);
495 
496 	priv = kzalloc(sizeof(struct cypress_private), GFP_KERNEL);
497 	if (!priv)
498 		return -ENOMEM;
499 
500 	priv->comm_is_ok = !0;
501 	spin_lock_init(&priv->lock);
502 	priv->buf = cypress_buf_alloc(CYPRESS_BUF_SIZE);
503 	if (priv->buf == NULL) {
504 		kfree(priv);
505 		return -ENOMEM;
506 	}
507 	init_waitqueue_head(&priv->delta_msr_wait);
508 
509 	usb_reset_configuration(serial->dev);
510 
511 	priv->cmd_ctrl = 0;
512 	priv->line_control = 0;
513 	priv->termios_initialized = 0;
514 	priv->rx_flags = 0;
515 	/* Default packet format setting is determined by packet size.
516 	   Anything with a size larger then 9 must have a separate
517 	   count field since the 3 bit count field is otherwise too
518 	   small.  Otherwise we can use the slightly more compact
519 	   format.  This is in accordance with the cypress_m8 serial
520 	   converter app note. */
521 	if (port->interrupt_out_size > 9)
522 		priv->pkt_fmt = packet_format_1;
523 	else
524 		priv->pkt_fmt = packet_format_2;
525 
526 	if (interval > 0) {
527 		priv->write_urb_interval = interval;
528 		priv->read_urb_interval = interval;
529 		dbg("%s - port %d read & write intervals forced to %d",
530 		    __func__, port->number, interval);
531 	} else {
532 		priv->write_urb_interval = port->interrupt_out_urb->interval;
533 		priv->read_urb_interval = port->interrupt_in_urb->interval;
534 		dbg("%s - port %d intervals: read=%d write=%d",
535 		    __func__, port->number,
536 		    priv->read_urb_interval, priv->write_urb_interval);
537 	}
538 	usb_set_serial_port_data(port, priv);
539 
540 	return 0;
541 }
542 
543 
544 static int cypress_earthmate_startup(struct usb_serial *serial)
545 {
546 	struct cypress_private *priv;
547 	struct usb_serial_port *port = serial->port[0];
548 
549 	dbg("%s", __func__);
550 
551 	if (generic_startup(serial)) {
552 		dbg("%s - Failed setting up port %d", __func__,
553 				port->number);
554 		return 1;
555 	}
556 
557 	priv = usb_get_serial_port_data(port);
558 	priv->chiptype = CT_EARTHMATE;
559 	/* All Earthmate devices use the separated-count packet
560 	   format!  Idiotic. */
561 	priv->pkt_fmt = packet_format_1;
562 	if (serial->dev->descriptor.idProduct !=
563 				cpu_to_le16(PRODUCT_ID_EARTHMATEUSB)) {
564 		/* The old original USB Earthmate seemed able to
565 		   handle GET_CONFIG requests; everything they've
566 		   produced since that time crashes if this command is
567 		   attempted :-( */
568 		dbg("%s - Marking this device as unsafe for GET_CONFIG "
569 		    "commands", __func__);
570 		priv->get_cfg_unsafe = !0;
571 	}
572 
573 	return 0;
574 } /* cypress_earthmate_startup */
575 
576 
577 static int cypress_hidcom_startup(struct usb_serial *serial)
578 {
579 	struct cypress_private *priv;
580 
581 	dbg("%s", __func__);
582 
583 	if (generic_startup(serial)) {
584 		dbg("%s - Failed setting up port %d", __func__,
585 				serial->port[0]->number);
586 		return 1;
587 	}
588 
589 	priv = usb_get_serial_port_data(serial->port[0]);
590 	priv->chiptype = CT_CYPHIDCOM;
591 
592 	return 0;
593 } /* cypress_hidcom_startup */
594 
595 
596 static int cypress_ca42v2_startup(struct usb_serial *serial)
597 {
598 	struct cypress_private *priv;
599 
600 	dbg("%s", __func__);
601 
602 	if (generic_startup(serial)) {
603 		dbg("%s - Failed setting up port %d", __func__,
604 				serial->port[0]->number);
605 		return 1;
606 	}
607 
608 	priv = usb_get_serial_port_data(serial->port[0]);
609 	priv->chiptype = CT_CA42V2;
610 
611 	return 0;
612 } /* cypress_ca42v2_startup */
613 
614 
615 static void cypress_shutdown(struct usb_serial *serial)
616 {
617 	struct cypress_private *priv;
618 
619 	dbg("%s - port %d", __func__, serial->port[0]->number);
620 
621 	/* all open ports are closed at this point */
622 
623 	priv = usb_get_serial_port_data(serial->port[0]);
624 
625 	if (priv) {
626 		cypress_buf_free(priv->buf);
627 		kfree(priv);
628 		usb_set_serial_port_data(serial->port[0], NULL);
629 	}
630 }
631 
632 
633 static int cypress_open(struct tty_struct *tty,
634 			struct usb_serial_port *port, struct file *filp)
635 {
636 	struct cypress_private *priv = usb_get_serial_port_data(port);
637 	struct usb_serial *serial = port->serial;
638 	unsigned long flags;
639 	int result = 0;
640 
641 	dbg("%s - port %d", __func__, port->number);
642 
643 	if (!priv->comm_is_ok)
644 		return -EIO;
645 
646 	/* clear halts before open */
647 	usb_clear_halt(serial->dev, 0x81);
648 	usb_clear_halt(serial->dev, 0x02);
649 
650 	spin_lock_irqsave(&priv->lock, flags);
651 	/* reset read/write statistics */
652 	priv->bytes_in = 0;
653 	priv->bytes_out = 0;
654 	priv->cmd_count = 0;
655 	priv->rx_flags = 0;
656 	spin_unlock_irqrestore(&priv->lock, flags);
657 
658 	/* setting to zero could cause data loss */
659 	if (tty)
660 		tty->low_latency = 1;
661 
662 	/* raise both lines and set termios */
663 	spin_lock_irqsave(&priv->lock, flags);
664 	priv->line_control = CONTROL_DTR | CONTROL_RTS;
665 	priv->cmd_ctrl = 1;
666 	spin_unlock_irqrestore(&priv->lock, flags);
667 	result = cypress_write(tty, port, NULL, 0);
668 
669 	if (result) {
670 		dev_err(&port->dev,
671 			"%s - failed setting the control lines - error %d\n",
672 							__func__, result);
673 		return result;
674 	} else
675 		dbg("%s - success setting the control lines", __func__);
676 
677 	if (tty)
678 		cypress_set_termios(tty, port, &priv->tmp_termios);
679 
680 	/* setup the port and start reading from the device */
681 	if (!port->interrupt_in_urb) {
682 		err("%s - interrupt_in_urb is empty!", __func__);
683 		return -1;
684 	}
685 
686 	usb_fill_int_urb(port->interrupt_in_urb, serial->dev,
687 		usb_rcvintpipe(serial->dev, port->interrupt_in_endpointAddress),
688 		port->interrupt_in_urb->transfer_buffer,
689 		port->interrupt_in_urb->transfer_buffer_length,
690 		cypress_read_int_callback, port, priv->read_urb_interval);
691 	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
692 
693 	if (result) {
694 		dev_err(&port->dev,
695 			"%s - failed submitting read urb, error %d\n",
696 							__func__, result);
697 		cypress_set_dead(port);
698 	}
699 
700 	return result;
701 } /* cypress_open */
702 
703 
704 static void cypress_close(struct tty_struct *tty,
705 			struct usb_serial_port *port, struct file *filp)
706 {
707 	struct cypress_private *priv = usb_get_serial_port_data(port);
708 	unsigned int c_cflag;
709 	int bps;
710 	long timeout;
711 	wait_queue_t wait;
712 
713 	dbg("%s - port %d", __func__, port->number);
714 
715 	/* wait for data to drain from buffer */
716 	spin_lock_irq(&priv->lock);
717 	timeout = CYPRESS_CLOSING_WAIT;
718 	init_waitqueue_entry(&wait, current);
719 	add_wait_queue(&tty->write_wait, &wait);
720 	for (;;) {
721 		set_current_state(TASK_INTERRUPTIBLE);
722 		if (cypress_buf_data_avail(priv->buf) == 0
723 		|| timeout == 0 || signal_pending(current)
724 		/* without mutex, allowed due to harmless failure mode */
725 		|| port->serial->disconnected)
726 			break;
727 		spin_unlock_irq(&priv->lock);
728 		timeout = schedule_timeout(timeout);
729 		spin_lock_irq(&priv->lock);
730 	}
731 	set_current_state(TASK_RUNNING);
732 	remove_wait_queue(&tty->write_wait, &wait);
733 	/* clear out any remaining data in the buffer */
734 	cypress_buf_clear(priv->buf);
735 	spin_unlock_irq(&priv->lock);
736 
737 	/* writing is potentially harmful, lock must be taken */
738 	mutex_lock(&port->serial->disc_mutex);
739 	if (port->serial->disconnected) {
740 		mutex_unlock(&port->serial->disc_mutex);
741 		return;
742 	}
743 	/* wait for characters to drain from device */
744 	if (tty) {
745 		bps = tty_get_baud_rate(tty);
746 		if (bps > 1200)
747 			timeout = max((HZ * 2560) / bps, HZ / 10);
748 		else
749 			timeout = 2 * HZ;
750 		schedule_timeout_interruptible(timeout);
751 	}
752 
753 	dbg("%s - stopping urbs", __func__);
754 	usb_kill_urb(port->interrupt_in_urb);
755 	usb_kill_urb(port->interrupt_out_urb);
756 
757 	if (tty) {
758 		c_cflag = tty->termios->c_cflag;
759 		if (c_cflag & HUPCL) {
760 			/* drop dtr and rts */
761 			priv = usb_get_serial_port_data(port);
762 			spin_lock_irq(&priv->lock);
763 			priv->line_control = 0;
764 			priv->cmd_ctrl = 1;
765 			spin_unlock_irq(&priv->lock);
766 			cypress_write(tty, port, NULL, 0);
767 		}
768 	}
769 
770 	if (stats)
771 		dev_info(&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",
772 			priv->bytes_in, priv->bytes_out, priv->cmd_count);
773 	mutex_unlock(&port->serial->disc_mutex);
774 } /* cypress_close */
775 
776 
777 static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
778 					const unsigned char *buf, int count)
779 {
780 	struct cypress_private *priv = usb_get_serial_port_data(port);
781 	unsigned long flags;
782 
783 	dbg("%s - port %d, %d bytes", __func__, port->number, count);
784 
785 	/* line control commands, which need to be executed immediately,
786 	   are not put into the buffer for obvious reasons.
787 	 */
788 	if (priv->cmd_ctrl) {
789 		count = 0;
790 		goto finish;
791 	}
792 
793 	if (!count)
794 		return count;
795 
796 	spin_lock_irqsave(&priv->lock, flags);
797 	count = cypress_buf_put(priv->buf, buf, count);
798 	spin_unlock_irqrestore(&priv->lock, flags);
799 
800 finish:
801 	cypress_send(port);
802 
803 	return count;
804 } /* cypress_write */
805 
806 
807 static void cypress_send(struct usb_serial_port *port)
808 {
809 	int count = 0, result, offset, actual_size;
810 	struct cypress_private *priv = usb_get_serial_port_data(port);
811 	unsigned long flags;
812 
813 	if (!priv->comm_is_ok)
814 		return;
815 
816 	dbg("%s - port %d", __func__, port->number);
817 	dbg("%s - interrupt out size is %d", __func__,
818 						port->interrupt_out_size);
819 
820 	spin_lock_irqsave(&priv->lock, flags);
821 	if (priv->write_urb_in_use) {
822 		dbg("%s - can't write, urb in use", __func__);
823 		spin_unlock_irqrestore(&priv->lock, flags);
824 		return;
825 	}
826 	spin_unlock_irqrestore(&priv->lock, flags);
827 
828 	/* clear buffer */
829 	memset(port->interrupt_out_urb->transfer_buffer, 0,
830 						port->interrupt_out_size);
831 
832 	spin_lock_irqsave(&priv->lock, flags);
833 	switch (priv->pkt_fmt) {
834 	default:
835 	case packet_format_1:
836 		/* this is for the CY7C64013... */
837 		offset = 2;
838 		port->interrupt_out_buffer[0] = priv->line_control;
839 		break;
840 	case packet_format_2:
841 		/* this is for the CY7C63743... */
842 		offset = 1;
843 		port->interrupt_out_buffer[0] = priv->line_control;
844 		break;
845 	}
846 
847 	if (priv->line_control & CONTROL_RESET)
848 		priv->line_control &= ~CONTROL_RESET;
849 
850 	if (priv->cmd_ctrl) {
851 		priv->cmd_count++;
852 		dbg("%s - line control command being issued", __func__);
853 		spin_unlock_irqrestore(&priv->lock, flags);
854 		goto send;
855 	} else
856 		spin_unlock_irqrestore(&priv->lock, flags);
857 
858 	count = cypress_buf_get(priv->buf, &port->interrupt_out_buffer[offset],
859 				port->interrupt_out_size-offset);
860 
861 	if (count == 0)
862 		return;
863 
864 	switch (priv->pkt_fmt) {
865 	default:
866 	case packet_format_1:
867 		port->interrupt_out_buffer[1] = count;
868 		break;
869 	case packet_format_2:
870 		port->interrupt_out_buffer[0] |= count;
871 	}
872 
873 	dbg("%s - count is %d", __func__, count);
874 
875 send:
876 	spin_lock_irqsave(&priv->lock, flags);
877 	priv->write_urb_in_use = 1;
878 	spin_unlock_irqrestore(&priv->lock, flags);
879 
880 	if (priv->cmd_ctrl)
881 		actual_size = 1;
882 	else
883 		actual_size = count +
884 			      (priv->pkt_fmt == packet_format_1 ? 2 : 1);
885 
886 	usb_serial_debug_data(debug, &port->dev, __func__,
887 		port->interrupt_out_size,
888 		port->interrupt_out_urb->transfer_buffer);
889 
890 	usb_fill_int_urb(port->interrupt_out_urb, port->serial->dev,
891 		usb_sndintpipe(port->serial->dev, port->interrupt_out_endpointAddress),
892 		port->interrupt_out_buffer, port->interrupt_out_size,
893 		cypress_write_int_callback, port, priv->write_urb_interval);
894 	result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
895 	if (result) {
896 		dev_err(&port->dev,
897 				"%s - failed submitting write urb, error %d\n",
898 							__func__, result);
899 		priv->write_urb_in_use = 0;
900 		cypress_set_dead(port);
901 	}
902 
903 	spin_lock_irqsave(&priv->lock, flags);
904 	if (priv->cmd_ctrl)
905 		priv->cmd_ctrl = 0;
906 
907 	/* do not count the line control and size bytes */
908 	priv->bytes_out += count;
909 	spin_unlock_irqrestore(&priv->lock, flags);
910 
911 	usb_serial_port_softint(port);
912 } /* cypress_send */
913 
914 
915 /* returns how much space is available in the soft buffer */
916 static int cypress_write_room(struct tty_struct *tty)
917 {
918 	struct usb_serial_port *port = tty->driver_data;
919 	struct cypress_private *priv = usb_get_serial_port_data(port);
920 	int room = 0;
921 	unsigned long flags;
922 
923 	dbg("%s - port %d", __func__, port->number);
924 
925 	spin_lock_irqsave(&priv->lock, flags);
926 	room = cypress_buf_space_avail(priv->buf);
927 	spin_unlock_irqrestore(&priv->lock, flags);
928 
929 	dbg("%s - returns %d", __func__, room);
930 	return room;
931 }
932 
933 
934 static int cypress_tiocmget(struct tty_struct *tty, struct file *file)
935 {
936 	struct usb_serial_port *port = tty->driver_data;
937 	struct cypress_private *priv = usb_get_serial_port_data(port);
938 	__u8 status, control;
939 	unsigned int result = 0;
940 	unsigned long flags;
941 
942 	dbg("%s - port %d", __func__, port->number);
943 
944 	spin_lock_irqsave(&priv->lock, flags);
945 	control = priv->line_control;
946 	status = priv->current_status;
947 	spin_unlock_irqrestore(&priv->lock, flags);
948 
949 	result = ((control & CONTROL_DTR)        ? TIOCM_DTR : 0)
950 		| ((control & CONTROL_RTS)       ? TIOCM_RTS : 0)
951 		| ((status & UART_CTS)        ? TIOCM_CTS : 0)
952 		| ((status & UART_DSR)        ? TIOCM_DSR : 0)
953 		| ((status & UART_RI)         ? TIOCM_RI  : 0)
954 		| ((status & UART_CD)         ? TIOCM_CD  : 0);
955 
956 	dbg("%s - result = %x", __func__, result);
957 
958 	return result;
959 }
960 
961 
962 static int cypress_tiocmset(struct tty_struct *tty, struct file *file,
963 			       unsigned int set, unsigned int clear)
964 {
965 	struct usb_serial_port *port = tty->driver_data;
966 	struct cypress_private *priv = usb_get_serial_port_data(port);
967 	unsigned long flags;
968 
969 	dbg("%s - port %d", __func__, port->number);
970 
971 	spin_lock_irqsave(&priv->lock, flags);
972 	if (set & TIOCM_RTS)
973 		priv->line_control |= CONTROL_RTS;
974 	if (set & TIOCM_DTR)
975 		priv->line_control |= CONTROL_DTR;
976 	if (clear & TIOCM_RTS)
977 		priv->line_control &= ~CONTROL_RTS;
978 	if (clear & TIOCM_DTR)
979 		priv->line_control &= ~CONTROL_DTR;
980 	priv->cmd_ctrl = 1;
981 	spin_unlock_irqrestore(&priv->lock, flags);
982 
983 	return cypress_write(tty, port, NULL, 0);
984 }
985 
986 
987 static int cypress_ioctl(struct tty_struct *tty, struct file *file,
988 					unsigned int cmd, unsigned long arg)
989 {
990 	struct usb_serial_port *port = tty->driver_data;
991 	struct cypress_private *priv = usb_get_serial_port_data(port);
992 
993 	dbg("%s - port %d, cmd 0x%.4x", __func__, port->number, cmd);
994 
995 	switch (cmd) {
996 	/* This code comes from drivers/char/serial.c and ftdi_sio.c */
997 	case TIOCMIWAIT:
998 		while (priv != NULL) {
999 			interruptible_sleep_on(&priv->delta_msr_wait);
1000 			/* see if a signal did it */
1001 			if (signal_pending(current))
1002 				return -ERESTARTSYS;
1003 			else {
1004 				char diff = priv->diff_status;
1005 				if (diff == 0)
1006 					return -EIO; /* no change => error */
1007 
1008 				/* consume all events */
1009 				priv->diff_status = 0;
1010 
1011 				/* return 0 if caller wanted to know about
1012 				   these bits */
1013 				if (((arg & TIOCM_RNG) && (diff & UART_RI)) ||
1014 				    ((arg & TIOCM_DSR) && (diff & UART_DSR)) ||
1015 				    ((arg & TIOCM_CD) && (diff & UART_CD)) ||
1016 				    ((arg & TIOCM_CTS) && (diff & UART_CTS)))
1017 					return 0;
1018 				/* otherwise caller can't care less about what
1019 				 * happened, and so we continue to wait for
1020 				 * more events.
1021 				 */
1022 			}
1023 		}
1024 		return 0;
1025 	default:
1026 		break;
1027 	}
1028 	dbg("%s - arg not supported - it was 0x%04x - check include/asm/ioctls.h", __func__, cmd);
1029 	return -ENOIOCTLCMD;
1030 } /* cypress_ioctl */
1031 
1032 
1033 static void cypress_set_termios(struct tty_struct *tty,
1034 	struct usb_serial_port *port, struct ktermios *old_termios)
1035 {
1036 	struct cypress_private *priv = usb_get_serial_port_data(port);
1037 	int data_bits, stop_bits, parity_type, parity_enable;
1038 	unsigned cflag, iflag;
1039 	unsigned long flags;
1040 	__u8 oldlines;
1041 	int linechange = 0;
1042 
1043 	dbg("%s - port %d", __func__, port->number);
1044 
1045 	spin_lock_irqsave(&priv->lock, flags);
1046 	if (!priv->termios_initialized) {
1047 		if (priv->chiptype == CT_EARTHMATE) {
1048 			*(tty->termios) = tty_std_termios;
1049 			tty->termios->c_cflag = B4800 | CS8 | CREAD | HUPCL |
1050 				CLOCAL;
1051 			tty->termios->c_ispeed = 4800;
1052 			tty->termios->c_ospeed = 4800;
1053 		} else if (priv->chiptype == CT_CYPHIDCOM) {
1054 			*(tty->termios) = tty_std_termios;
1055 			tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL |
1056 				CLOCAL;
1057 			tty->termios->c_ispeed = 9600;
1058 			tty->termios->c_ospeed = 9600;
1059 		} else if (priv->chiptype == CT_CA42V2) {
1060 			*(tty->termios) = tty_std_termios;
1061 			tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL |
1062 				CLOCAL;
1063 			tty->termios->c_ispeed = 9600;
1064 			tty->termios->c_ospeed = 9600;
1065 		}
1066 		priv->termios_initialized = 1;
1067 	}
1068 	spin_unlock_irqrestore(&priv->lock, flags);
1069 
1070 	/* Unsupported features need clearing */
1071 	tty->termios->c_cflag &= ~(CMSPAR|CRTSCTS);
1072 
1073 	cflag = tty->termios->c_cflag;
1074 	iflag = tty->termios->c_iflag;
1075 
1076 	/* check if there are new settings */
1077 	if (old_termios) {
1078 		spin_lock_irqsave(&priv->lock, flags);
1079 		priv->tmp_termios = *(tty->termios);
1080 		spin_unlock_irqrestore(&priv->lock, flags);
1081 	}
1082 
1083 	/* set number of data bits, parity, stop bits */
1084 	/* when parity is disabled the parity type bit is ignored */
1085 
1086 	/* 1 means 2 stop bits, 0 means 1 stop bit */
1087 	stop_bits = cflag & CSTOPB ? 1 : 0;
1088 
1089 	if (cflag & PARENB) {
1090 		parity_enable = 1;
1091 		/* 1 means odd parity, 0 means even parity */
1092 		parity_type = cflag & PARODD ? 1 : 0;
1093 	} else
1094 		parity_enable = parity_type = 0;
1095 
1096 	switch (cflag & CSIZE) {
1097 	case CS5:
1098 		data_bits = 0;
1099 		break;
1100 	case CS6:
1101 		data_bits = 1;
1102 		break;
1103 	case CS7:
1104 		data_bits = 2;
1105 		break;
1106 	case CS8:
1107 		data_bits = 3;
1108 		break;
1109 	default:
1110 		err("%s - CSIZE was set, but not CS5-CS8",
1111 				__func__);
1112 		data_bits = 3;
1113 	}
1114 	spin_lock_irqsave(&priv->lock, flags);
1115 	oldlines = priv->line_control;
1116 	if ((cflag & CBAUD) == B0) {
1117 		/* drop dtr and rts */
1118 		dbg("%s - dropping the lines, baud rate 0bps", __func__);
1119 		priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
1120 	} else
1121 		priv->line_control = (CONTROL_DTR | CONTROL_RTS);
1122 	spin_unlock_irqrestore(&priv->lock, flags);
1123 
1124 	dbg("%s - sending %d stop_bits, %d parity_enable, %d parity_type, "
1125 			"%d data_bits (+5)", __func__, stop_bits,
1126 			parity_enable, parity_type, data_bits);
1127 
1128 	cypress_serial_control(tty, port, tty_get_baud_rate(tty),
1129 			data_bits, stop_bits,
1130 			parity_enable, parity_type,
1131 			0, CYPRESS_SET_CONFIG);
1132 
1133 	/* we perform a CYPRESS_GET_CONFIG so that the current settings are
1134 	 * filled into the private structure this should confirm that all is
1135 	 * working if it returns what we just set */
1136 	cypress_serial_control(tty, port, 0, 0, 0, 0, 0, 0, CYPRESS_GET_CONFIG);
1137 
1138 	/* Here we can define custom tty settings for devices; the main tty
1139 	 * termios flag base comes from empeg.c */
1140 
1141 	spin_lock_irqsave(&priv->lock, flags);
1142 	if (priv->chiptype == CT_EARTHMATE && priv->baud_rate == 4800) {
1143 		dbg("Using custom termios settings for a baud rate of "
1144 				"4800bps.");
1145 		/* define custom termios settings for NMEA protocol */
1146 
1147 		tty->termios->c_iflag /* input modes - */
1148 			&= ~(IGNBRK  /* disable ignore break */
1149 			| BRKINT     /* disable break causes interrupt */
1150 			| PARMRK     /* disable mark parity errors */
1151 			| ISTRIP     /* disable clear high bit of input char */
1152 			| INLCR      /* disable translate NL to CR */
1153 			| IGNCR      /* disable ignore CR */
1154 			| ICRNL      /* disable translate CR to NL */
1155 			| IXON);     /* disable enable XON/XOFF flow control */
1156 
1157 		tty->termios->c_oflag /* output modes */
1158 			&= ~OPOST;    /* disable postprocess output char */
1159 
1160 		tty->termios->c_lflag /* line discipline modes */
1161 			&= ~(ECHO     /* disable echo input characters */
1162 			| ECHONL      /* disable echo new line */
1163 			| ICANON      /* disable erase, kill, werase, and rprnt
1164 					 special characters */
1165 			| ISIG        /* disable interrupt, quit, and suspend
1166 					 special characters */
1167 			| IEXTEN);    /* disable non-POSIX special characters */
1168 	} /* CT_CYPHIDCOM: Application should handle this for device */
1169 
1170 	linechange = (priv->line_control != oldlines);
1171 	spin_unlock_irqrestore(&priv->lock, flags);
1172 
1173 	/* if necessary, set lines */
1174 	if (linechange) {
1175 		priv->cmd_ctrl = 1;
1176 		cypress_write(tty, port, NULL, 0);
1177 	}
1178 } /* cypress_set_termios */
1179 
1180 
1181 /* returns amount of data still left in soft buffer */
1182 static int cypress_chars_in_buffer(struct tty_struct *tty)
1183 {
1184 	struct usb_serial_port *port = tty->driver_data;
1185 	struct cypress_private *priv = usb_get_serial_port_data(port);
1186 	int chars = 0;
1187 	unsigned long flags;
1188 
1189 	dbg("%s - port %d", __func__, port->number);
1190 
1191 	spin_lock_irqsave(&priv->lock, flags);
1192 	chars = cypress_buf_data_avail(priv->buf);
1193 	spin_unlock_irqrestore(&priv->lock, flags);
1194 
1195 	dbg("%s - returns %d", __func__, chars);
1196 	return chars;
1197 }
1198 
1199 
1200 static void cypress_throttle(struct tty_struct *tty)
1201 {
1202 	struct usb_serial_port *port = tty->driver_data;
1203 	struct cypress_private *priv = usb_get_serial_port_data(port);
1204 	unsigned long flags;
1205 
1206 	dbg("%s - port %d", __func__, port->number);
1207 
1208 	spin_lock_irqsave(&priv->lock, flags);
1209 	priv->rx_flags = THROTTLED;
1210 	spin_unlock_irqrestore(&priv->lock, flags);
1211 }
1212 
1213 
1214 static void cypress_unthrottle(struct tty_struct *tty)
1215 {
1216 	struct usb_serial_port *port = tty->driver_data;
1217 	struct cypress_private *priv = usb_get_serial_port_data(port);
1218 	int actually_throttled, result;
1219 	unsigned long flags;
1220 
1221 	dbg("%s - port %d", __func__, port->number);
1222 
1223 	spin_lock_irqsave(&priv->lock, flags);
1224 	actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
1225 	priv->rx_flags = 0;
1226 	spin_unlock_irqrestore(&priv->lock, flags);
1227 
1228 	if (!priv->comm_is_ok)
1229 		return;
1230 
1231 	if (actually_throttled) {
1232 		port->interrupt_in_urb->dev = port->serial->dev;
1233 
1234 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1235 		if (result) {
1236 			dev_err(&port->dev, "%s - failed submitting read urb, "
1237 					"error %d\n", __func__, result);
1238 			cypress_set_dead(port);
1239 		}
1240 	}
1241 }
1242 
1243 
1244 static void cypress_read_int_callback(struct urb *urb)
1245 {
1246 	struct usb_serial_port *port = urb->context;
1247 	struct cypress_private *priv = usb_get_serial_port_data(port);
1248 	struct tty_struct *tty;
1249 	unsigned char *data = urb->transfer_buffer;
1250 	unsigned long flags;
1251 	char tty_flag = TTY_NORMAL;
1252 	int havedata = 0;
1253 	int bytes = 0;
1254 	int result;
1255 	int i = 0;
1256 	int status = urb->status;
1257 
1258 	dbg("%s - port %d", __func__, port->number);
1259 
1260 	switch (status) {
1261 	case 0: /* success */
1262 		break;
1263 	case -ECONNRESET:
1264 	case -ENOENT:
1265 	case -ESHUTDOWN:
1266 		/* precursor to disconnect so just go away */
1267 		return;
1268 	case -EPIPE:
1269 		usb_clear_halt(port->serial->dev, 0x81);
1270 		break;
1271 	default:
1272 		/* something ugly is going on... */
1273 		dev_err(&urb->dev->dev,
1274 			"%s - unexpected nonzero read status received: %d\n",
1275 							__func__, status);
1276 		cypress_set_dead(port);
1277 		return;
1278 	}
1279 
1280 	spin_lock_irqsave(&priv->lock, flags);
1281 	if (priv->rx_flags & THROTTLED) {
1282 		dbg("%s - now throttling", __func__);
1283 		priv->rx_flags |= ACTUALLY_THROTTLED;
1284 		spin_unlock_irqrestore(&priv->lock, flags);
1285 		return;
1286 	}
1287 	spin_unlock_irqrestore(&priv->lock, flags);
1288 
1289 	tty = port->port.tty;
1290 	if (!tty) {
1291 		dbg("%s - bad tty pointer - exiting", __func__);
1292 		return;
1293 	}
1294 
1295 	spin_lock_irqsave(&priv->lock, flags);
1296 	result = urb->actual_length;
1297 	switch (priv->pkt_fmt) {
1298 	default:
1299 	case packet_format_1:
1300 		/* This is for the CY7C64013... */
1301 		priv->current_status = data[0] & 0xF8;
1302 		bytes = data[1] + 2;
1303 		i = 2;
1304 		if (bytes > 2)
1305 			havedata = 1;
1306 		break;
1307 	case packet_format_2:
1308 		/* This is for the CY7C63743... */
1309 		priv->current_status = data[0] & 0xF8;
1310 		bytes = (data[0] & 0x07) + 1;
1311 		i = 1;
1312 		if (bytes > 1)
1313 			havedata = 1;
1314 		break;
1315 	}
1316 	spin_unlock_irqrestore(&priv->lock, flags);
1317 	if (result < bytes) {
1318 		dbg("%s - wrong packet size - received %d bytes but packet "
1319 		    "said %d bytes", __func__, result, bytes);
1320 		goto continue_read;
1321 	}
1322 
1323 	usb_serial_debug_data(debug, &port->dev, __func__,
1324 						urb->actual_length, data);
1325 
1326 	spin_lock_irqsave(&priv->lock, flags);
1327 	/* check to see if status has changed */
1328 	if (priv->current_status != priv->prev_status) {
1329 		priv->diff_status |= priv->current_status ^
1330 			priv->prev_status;
1331 		wake_up_interruptible(&priv->delta_msr_wait);
1332 		priv->prev_status = priv->current_status;
1333 	}
1334 	spin_unlock_irqrestore(&priv->lock, flags);
1335 
1336 	/* hangup, as defined in acm.c... this might be a bad place for it
1337 	 * though */
1338 	if (tty && !(tty->termios->c_cflag & CLOCAL) &&
1339 			!(priv->current_status & UART_CD)) {
1340 		dbg("%s - calling hangup", __func__);
1341 		tty_hangup(tty);
1342 		goto continue_read;
1343 	}
1344 
1345 	/* There is one error bit... I'm assuming it is a parity error
1346 	 * indicator as the generic firmware will set this bit to 1 if a
1347 	 * parity error occurs.
1348 	 * I can not find reference to any other error events. */
1349 	spin_lock_irqsave(&priv->lock, flags);
1350 	if (priv->current_status & CYP_ERROR) {
1351 		spin_unlock_irqrestore(&priv->lock, flags);
1352 		tty_flag = TTY_PARITY;
1353 		dbg("%s - Parity Error detected", __func__);
1354 	} else
1355 		spin_unlock_irqrestore(&priv->lock, flags);
1356 
1357 	/* process read if there is data other than line status */
1358 	if (tty && (bytes > i)) {
1359 		bytes = tty_buffer_request_room(tty, bytes);
1360 		for (; i < bytes ; ++i) {
1361 			dbg("pushing byte number %d - %d - %c", i, data[i],
1362 					data[i]);
1363 			tty_insert_flip_char(tty, data[i], tty_flag);
1364 		}
1365 		tty_flip_buffer_push(port->port.tty);
1366 	}
1367 
1368 	spin_lock_irqsave(&priv->lock, flags);
1369 	/* control and status byte(s) are also counted */
1370 	priv->bytes_in += bytes;
1371 	spin_unlock_irqrestore(&priv->lock, flags);
1372 
1373 continue_read:
1374 
1375 	/* Continue trying to always read... unless the port has closed. */
1376 
1377 	if (port->port.count > 0 && priv->comm_is_ok) {
1378 		usb_fill_int_urb(port->interrupt_in_urb, port->serial->dev,
1379 				usb_rcvintpipe(port->serial->dev,
1380 					port->interrupt_in_endpointAddress),
1381 				port->interrupt_in_urb->transfer_buffer,
1382 				port->interrupt_in_urb->transfer_buffer_length,
1383 				cypress_read_int_callback, port,
1384 				priv->read_urb_interval);
1385 		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
1386 		if (result) {
1387 			dev_err(&urb->dev->dev, "%s - failed resubmitting "
1388 					"read urb, error %d\n", __func__,
1389 					result);
1390 			cypress_set_dead(port);
1391 		}
1392 	}
1393 
1394 	return;
1395 } /* cypress_read_int_callback */
1396 
1397 
1398 static void cypress_write_int_callback(struct urb *urb)
1399 {
1400 	struct usb_serial_port *port = urb->context;
1401 	struct cypress_private *priv = usb_get_serial_port_data(port);
1402 	int result;
1403 	int status = urb->status;
1404 
1405 	dbg("%s - port %d", __func__, port->number);
1406 
1407 	switch (status) {
1408 	case 0:
1409 		/* success */
1410 		break;
1411 	case -ECONNRESET:
1412 	case -ENOENT:
1413 	case -ESHUTDOWN:
1414 		/* this urb is terminated, clean up */
1415 		dbg("%s - urb shutting down with status: %d",
1416 						__func__, status);
1417 		priv->write_urb_in_use = 0;
1418 		return;
1419 	case -EPIPE: /* no break needed; clear halt and resubmit */
1420 		if (!priv->comm_is_ok)
1421 			break;
1422 		usb_clear_halt(port->serial->dev, 0x02);
1423 		/* error in the urb, so we have to resubmit it */
1424 		dbg("%s - nonzero write bulk status received: %d",
1425 			__func__, status);
1426 		port->interrupt_out_urb->transfer_buffer_length = 1;
1427 		port->interrupt_out_urb->dev = port->serial->dev;
1428 		result = usb_submit_urb(port->interrupt_out_urb, GFP_ATOMIC);
1429 		if (!result)
1430 			return;
1431 		dev_err(&urb->dev->dev,
1432 			"%s - failed resubmitting write urb, error %d\n",
1433 							__func__, result);
1434 		cypress_set_dead(port);
1435 		break;
1436 	default:
1437 		dev_err(&urb->dev->dev,
1438 			 "%s - unexpected nonzero write status received: %d\n",
1439 							__func__, status);
1440 		cypress_set_dead(port);
1441 		break;
1442 	}
1443 	priv->write_urb_in_use = 0;
1444 
1445 	/* send any buffered data */
1446 	cypress_send(port);
1447 }
1448 
1449 
1450 /*****************************************************************************
1451  * Write buffer functions - buffering code from pl2303 used
1452  *****************************************************************************/
1453 
1454 /*
1455  * cypress_buf_alloc
1456  *
1457  * Allocate a circular buffer and all associated memory.
1458  */
1459 
1460 static struct cypress_buf *cypress_buf_alloc(unsigned int size)
1461 {
1462 
1463 	struct cypress_buf *cb;
1464 
1465 
1466 	if (size == 0)
1467 		return NULL;
1468 
1469 	cb = kmalloc(sizeof(struct cypress_buf), GFP_KERNEL);
1470 	if (cb == NULL)
1471 		return NULL;
1472 
1473 	cb->buf_buf = kmalloc(size, GFP_KERNEL);
1474 	if (cb->buf_buf == NULL) {
1475 		kfree(cb);
1476 		return NULL;
1477 	}
1478 
1479 	cb->buf_size = size;
1480 	cb->buf_get = cb->buf_put = cb->buf_buf;
1481 
1482 	return cb;
1483 
1484 }
1485 
1486 
1487 /*
1488  * cypress_buf_free
1489  *
1490  * Free the buffer and all associated memory.
1491  */
1492 
1493 static void cypress_buf_free(struct cypress_buf *cb)
1494 {
1495 	if (cb) {
1496 		kfree(cb->buf_buf);
1497 		kfree(cb);
1498 	}
1499 }
1500 
1501 
1502 /*
1503  * cypress_buf_clear
1504  *
1505  * Clear out all data in the circular buffer.
1506  */
1507 
1508 static void cypress_buf_clear(struct cypress_buf *cb)
1509 {
1510 	if (cb != NULL)
1511 		cb->buf_get = cb->buf_put;
1512 		/* equivalent to a get of all data available */
1513 }
1514 
1515 
1516 /*
1517  * cypress_buf_data_avail
1518  *
1519  * Return the number of bytes of data available in the circular
1520  * buffer.
1521  */
1522 
1523 static unsigned int cypress_buf_data_avail(struct cypress_buf *cb)
1524 {
1525 	if (cb != NULL)
1526 		return (cb->buf_size + cb->buf_put - cb->buf_get)
1527 							% cb->buf_size;
1528 	else
1529 		return 0;
1530 }
1531 
1532 
1533 /*
1534  * cypress_buf_space_avail
1535  *
1536  * Return the number of bytes of space available in the circular
1537  * buffer.
1538  */
1539 
1540 static unsigned int cypress_buf_space_avail(struct cypress_buf *cb)
1541 {
1542 	if (cb != NULL)
1543 		return (cb->buf_size + cb->buf_get - cb->buf_put - 1)
1544 							% cb->buf_size;
1545 	else
1546 		return 0;
1547 }
1548 
1549 
1550 /*
1551  * cypress_buf_put
1552  *
1553  * Copy data data from a user buffer and put it into the circular buffer.
1554  * Restrict to the amount of space available.
1555  *
1556  * Return the number of bytes copied.
1557  */
1558 
1559 static unsigned int cypress_buf_put(struct cypress_buf *cb, const char *buf,
1560 	unsigned int count)
1561 {
1562 
1563 	unsigned int len;
1564 
1565 
1566 	if (cb == NULL)
1567 		return 0;
1568 
1569 	len  = cypress_buf_space_avail(cb);
1570 	if (count > len)
1571 		count = len;
1572 
1573 	if (count == 0)
1574 		return 0;
1575 
1576 	len = cb->buf_buf + cb->buf_size - cb->buf_put;
1577 	if (count > len) {
1578 		memcpy(cb->buf_put, buf, len);
1579 		memcpy(cb->buf_buf, buf+len, count - len);
1580 		cb->buf_put = cb->buf_buf + count - len;
1581 	} else {
1582 		memcpy(cb->buf_put, buf, count);
1583 		if (count < len)
1584 			cb->buf_put += count;
1585 		else /* count == len */
1586 			cb->buf_put = cb->buf_buf;
1587 	}
1588 
1589 	return count;
1590 
1591 }
1592 
1593 
1594 /*
1595  * cypress_buf_get
1596  *
1597  * Get data from the circular buffer and copy to the given buffer.
1598  * Restrict to the amount of data available.
1599  *
1600  * Return the number of bytes copied.
1601  */
1602 
1603 static unsigned int cypress_buf_get(struct cypress_buf *cb, char *buf,
1604 	unsigned int count)
1605 {
1606 
1607 	unsigned int len;
1608 
1609 
1610 	if (cb == NULL)
1611 		return 0;
1612 
1613 	len = cypress_buf_data_avail(cb);
1614 	if (count > len)
1615 		count = len;
1616 
1617 	if (count == 0)
1618 		return 0;
1619 
1620 	len = cb->buf_buf + cb->buf_size - cb->buf_get;
1621 	if (count > len) {
1622 		memcpy(buf, cb->buf_get, len);
1623 		memcpy(buf+len, cb->buf_buf, count - len);
1624 		cb->buf_get = cb->buf_buf + count - len;
1625 	} else {
1626 		memcpy(buf, cb->buf_get, count);
1627 		if (count < len)
1628 			cb->buf_get += count;
1629 		else /* count == len */
1630 			cb->buf_get = cb->buf_buf;
1631 	}
1632 
1633 	return count;
1634 
1635 }
1636 
1637 /*****************************************************************************
1638  * Module functions
1639  *****************************************************************************/
1640 
1641 static int __init cypress_init(void)
1642 {
1643 	int retval;
1644 
1645 	dbg("%s", __func__);
1646 
1647 	retval = usb_serial_register(&cypress_earthmate_device);
1648 	if (retval)
1649 		goto failed_em_register;
1650 	retval = usb_serial_register(&cypress_hidcom_device);
1651 	if (retval)
1652 		goto failed_hidcom_register;
1653 	retval = usb_serial_register(&cypress_ca42v2_device);
1654 	if (retval)
1655 		goto failed_ca42v2_register;
1656 	retval = usb_register(&cypress_driver);
1657 	if (retval)
1658 		goto failed_usb_register;
1659 
1660 	info(DRIVER_DESC " " DRIVER_VERSION);
1661 	return 0;
1662 
1663 failed_usb_register:
1664 	usb_serial_deregister(&cypress_ca42v2_device);
1665 failed_ca42v2_register:
1666 	usb_serial_deregister(&cypress_hidcom_device);
1667 failed_hidcom_register:
1668 	usb_serial_deregister(&cypress_earthmate_device);
1669 failed_em_register:
1670 	return retval;
1671 }
1672 
1673 
1674 static void __exit cypress_exit(void)
1675 {
1676 	dbg("%s", __func__);
1677 
1678 	usb_deregister(&cypress_driver);
1679 	usb_serial_deregister(&cypress_earthmate_device);
1680 	usb_serial_deregister(&cypress_hidcom_device);
1681 	usb_serial_deregister(&cypress_ca42v2_device);
1682 }
1683 
1684 
1685 module_init(cypress_init);
1686 module_exit(cypress_exit);
1687 
1688 MODULE_AUTHOR(DRIVER_AUTHOR);
1689 MODULE_DESCRIPTION(DRIVER_DESC);
1690 MODULE_VERSION(DRIVER_VERSION);
1691 MODULE_LICENSE("GPL");
1692 
1693 module_param(debug, bool, S_IRUGO | S_IWUSR);
1694 MODULE_PARM_DESC(debug, "Debug enabled or not");
1695 module_param(stats, bool, S_IRUGO | S_IWUSR);
1696 MODULE_PARM_DESC(stats, "Enable statistics or not");
1697 module_param(interval, int, S_IRUGO | S_IWUSR);
1698 MODULE_PARM_DESC(interval, "Overrides interrupt interval");
1699