xref: /linux/drivers/usb/serial/garmin_gps.c (revision f58899bb0224741eb0409ada67ecafe90ba137ef)
1 /*
2  * Garmin GPS driver
3  *
4  * Copyright (C) 2006,2007 Hermann Kneissel herkne@users.sourceforge.net
5  *
6  * The latest version of the driver can be found at
7  * http://sourceforge.net/projects/garmin-gps/
8  *
9  * This driver has been derived from v2.1 of the visor driver.
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111 USA
24  */
25 
26 #include <linux/kernel.h>
27 #include <linux/errno.h>
28 #include <linux/init.h>
29 #include <linux/slab.h>
30 #include <linux/timer.h>
31 #include <linux/tty.h>
32 #include <linux/tty_driver.h>
33 #include <linux/tty_flip.h>
34 #include <linux/module.h>
35 #include <linux/spinlock.h>
36 #include <linux/uaccess.h>
37 #include <asm/atomic.h>
38 #include <linux/usb.h>
39 #include <linux/usb/serial.h>
40 
41 /* the mode to be set when the port ist opened */
42 static int initial_mode = 1;
43 
44 /* debug flag */
45 static int debug;
46 
47 #define GARMIN_VENDOR_ID             0x091E
48 
49 /*
50  * Version Information
51  */
52 
53 #define VERSION_MAJOR	0
54 #define VERSION_MINOR	31
55 
56 #define _STR(s) #s
57 #define _DRIVER_VERSION(a, b) "v" _STR(a) "." _STR(b)
58 #define DRIVER_VERSION _DRIVER_VERSION(VERSION_MAJOR, VERSION_MINOR)
59 #define DRIVER_AUTHOR "hermann kneissel"
60 #define DRIVER_DESC "garmin gps driver"
61 
62 /* error codes returned by the driver */
63 #define EINVPKT	1000	/* invalid packet structure */
64 
65 
66 /* size of the header of a packet using the usb protocol */
67 #define GARMIN_PKTHDR_LENGTH	12
68 
69 /* max. possible size of a packet using the serial protocol */
70 #define MAX_SERIAL_PKT_SIZ (3 + 255 + 3)
71 
72 /*  max. possible size of a packet with worst case stuffing */
73 #define MAX_SERIAL_PKT_SIZ_STUFFED (MAX_SERIAL_PKT_SIZ + 256)
74 
75 /* size of a buffer able to hold a complete (no stuffing) packet
76  * (the document protocol does not contain packets with a larger
77  *  size, but in theory a packet may be 64k+12 bytes - if in
78  *  later protocol versions larger packet sizes occur, this value
79  *  should be increased accordingly, so the input buffer is always
80  *  large enough the store a complete packet inclusive header) */
81 #define GPS_IN_BUFSIZ  (GARMIN_PKTHDR_LENGTH+MAX_SERIAL_PKT_SIZ)
82 
83 /* size of a buffer able to hold a complete (incl. stuffing) packet */
84 #define GPS_OUT_BUFSIZ (GARMIN_PKTHDR_LENGTH+MAX_SERIAL_PKT_SIZ_STUFFED)
85 
86 /* where to place the packet id of a serial packet, so we can
87  * prepend the usb-packet header without the need to move the
88  * packets data */
89 #define GSP_INITIAL_OFFSET (GARMIN_PKTHDR_LENGTH-2)
90 
91 /* max. size of incoming private packets (header+1 param) */
92 #define PRIVPKTSIZ (GARMIN_PKTHDR_LENGTH+4)
93 
94 #define GARMIN_LAYERID_TRANSPORT  0
95 #define GARMIN_LAYERID_APPL      20
96 /* our own layer-id to use for some control mechanisms */
97 #define GARMIN_LAYERID_PRIVATE	0x01106E4B
98 
99 #define GARMIN_PKTID_PVT_DATA	51
100 #define GARMIN_PKTID_L001_COMMAND_DATA 10
101 
102 #define CMND_ABORT_TRANSFER 0
103 
104 /* packet ids used in private layer */
105 #define PRIV_PKTID_SET_DEBUG	1
106 #define PRIV_PKTID_SET_MODE	2
107 #define PRIV_PKTID_INFO_REQ	3
108 #define PRIV_PKTID_INFO_RESP	4
109 #define PRIV_PKTID_RESET_REQ	5
110 #define PRIV_PKTID_SET_DEF_MODE	6
111 
112 
113 #define ETX	0x03
114 #define DLE	0x10
115 #define ACK	0x06
116 #define NAK	0x15
117 
118 /* structure used to queue incoming packets */
119 struct garmin_packet {
120 	struct list_head  list;
121 	int               seq;
122 	/* the real size of the data array, always > 0 */
123 	int               size;
124 	__u8              data[1];
125 };
126 
127 /* structure used to keep the current state of the driver */
128 struct garmin_data {
129 	__u8   state;
130 	__u16  flags;
131 	__u8   mode;
132 	__u8   ignorePkts;
133 	__u8   count;
134 	__u8   pkt_id;
135 	__u32  serial_num;
136 	struct timer_list timer;
137 	struct usb_serial_port *port;
138 	int    seq_counter;
139 	int    insize;
140 	int    outsize;
141 	__u8   inbuffer [GPS_IN_BUFSIZ];  /* tty -> usb */
142 	__u8   outbuffer[GPS_OUT_BUFSIZ]; /* usb -> tty */
143 	__u8   privpkt[4*6];
144 	atomic_t req_count;
145 	atomic_t resp_count;
146 	spinlock_t lock;
147 	struct list_head pktlist;
148 };
149 
150 
151 #define STATE_NEW            0
152 #define STATE_INITIAL_DELAY  1
153 #define STATE_TIMEOUT        2
154 #define STATE_SESSION_REQ1   3
155 #define STATE_SESSION_REQ2   4
156 #define STATE_ACTIVE         5
157 
158 #define STATE_RESET	     8
159 #define STATE_DISCONNECTED   9
160 #define STATE_WAIT_TTY_ACK  10
161 #define STATE_GSP_WAIT_DATA 11
162 
163 #define MODE_NATIVE          0
164 #define MODE_GARMIN_SERIAL   1
165 
166 /* Flags used in garmin_data.flags: */
167 #define FLAGS_SESSION_REPLY_MASK  0x00C0
168 #define FLAGS_SESSION_REPLY1_SEEN 0x0080
169 #define FLAGS_SESSION_REPLY2_SEEN 0x0040
170 #define FLAGS_BULK_IN_ACTIVE      0x0020
171 #define FLAGS_BULK_IN_RESTART     0x0010
172 #define FLAGS_THROTTLED           0x0008
173 #define CLEAR_HALT_REQUIRED       0x0001
174 
175 #define FLAGS_QUEUING             0x0100
176 #define FLAGS_DROP_DATA           0x0800
177 
178 #define FLAGS_GSP_SKIP            0x1000
179 #define FLAGS_GSP_DLESEEN         0x2000
180 
181 
182 
183 
184 
185 
186 /* function prototypes */
187 static void gsp_next_packet(struct garmin_data *garmin_data_p);
188 static int  garmin_write_bulk(struct usb_serial_port *port,
189 			     const unsigned char *buf, int count,
190 			     int dismiss_ack);
191 
192 /* some special packets to be send or received */
193 static unsigned char const GARMIN_START_SESSION_REQ[]
194 	= { 0, 0, 0, 0,  5, 0, 0, 0, 0, 0, 0, 0 };
195 static unsigned char const GARMIN_START_SESSION_REQ2[]
196 	= { 0, 0, 0, 0, 16, 0, 0, 0, 0, 0, 0, 0 };
197 static unsigned char const GARMIN_START_SESSION_REPLY[]
198 	= { 0, 0, 0, 0,  6, 0, 0, 0, 4, 0, 0, 0 };
199 static unsigned char const GARMIN_SESSION_ACTIVE_REPLY[]
200 	= { 0, 0, 0, 0, 17, 0, 0, 0, 4, 0, 0, 0, 0, 16, 0, 0 };
201 static unsigned char const GARMIN_BULK_IN_AVAIL_REPLY[]
202 	= { 0, 0, 0, 0,  2, 0, 0, 0, 0, 0, 0, 0 };
203 static unsigned char const GARMIN_APP_LAYER_REPLY[]
204 	= { 0x14, 0, 0, 0 };
205 static unsigned char const GARMIN_START_PVT_REQ[]
206 	= { 20, 0, 0, 0,  10, 0, 0, 0, 2, 0, 0, 0, 49, 0 };
207 static unsigned char const GARMIN_STOP_PVT_REQ[]
208 	= { 20, 0, 0, 0,  10, 0, 0, 0, 2, 0, 0, 0, 50, 0 };
209 static unsigned char const GARMIN_STOP_TRANSFER_REQ[]
210 	= { 20, 0, 0, 0,  10, 0, 0, 0, 2, 0, 0, 0, 0, 0 };
211 static unsigned char const GARMIN_STOP_TRANSFER_REQ_V2[]
212 	= { 20, 0, 0, 0,  10, 0, 0, 0, 1, 0, 0, 0, 0 };
213 static unsigned char const PRIVATE_REQ[]
214 	=    { 0x4B, 0x6E, 0x10, 0x01,  0xFF, 0, 0, 0, 0xFF, 0, 0, 0 };
215 
216 
217 
218 static struct usb_device_id id_table [] = {
219 	/* the same device id seems to be used by all
220 	   usb enabled GPS devices */
221 	{ USB_DEVICE(GARMIN_VENDOR_ID, 3) },
222 	{ }					/* Terminating entry */
223 };
224 
225 MODULE_DEVICE_TABLE(usb, id_table);
226 
227 static struct usb_driver garmin_driver = {
228 	.name =		"garmin_gps",
229 	.probe =	usb_serial_probe,
230 	.disconnect =	usb_serial_disconnect,
231 	.id_table =	id_table,
232 	.no_dynamic_id = 1,
233 };
234 
235 
236 static inline int noResponseFromAppLayer(struct garmin_data *garmin_data_p)
237 {
238 	return atomic_read(&garmin_data_p->req_count) ==
239 				atomic_read(&garmin_data_p->resp_count);
240 }
241 
242 
243 static inline int getLayerId(const __u8 *usbPacket)
244 {
245 	return __le32_to_cpup((__le32 *)(usbPacket));
246 }
247 
248 static inline int getPacketId(const __u8 *usbPacket)
249 {
250 	return __le32_to_cpup((__le32 *)(usbPacket+4));
251 }
252 
253 static inline int getDataLength(const __u8 *usbPacket)
254 {
255 	return __le32_to_cpup((__le32 *)(usbPacket+8));
256 }
257 
258 
259 /*
260  * check if the usb-packet in buf contains an abort-transfer command.
261  * (if yes, all queued data will be dropped)
262  */
263 static inline int isAbortTrfCmnd(const unsigned char *buf)
264 {
265 	if (0 == memcmp(buf, GARMIN_STOP_TRANSFER_REQ,
266 					sizeof(GARMIN_STOP_TRANSFER_REQ)) ||
267 	    0 == memcmp(buf, GARMIN_STOP_TRANSFER_REQ_V2,
268 					sizeof(GARMIN_STOP_TRANSFER_REQ_V2)))
269 		return 1;
270 	else
271 		return 0;
272 }
273 
274 
275 
276 static void send_to_tty(struct usb_serial_port *port,
277 			char *data, unsigned int actual_length)
278 {
279 	struct tty_struct *tty = port->port.tty;
280 
281 	if (tty && actual_length) {
282 
283 		usb_serial_debug_data(debug, &port->dev,
284 					__func__, actual_length, data);
285 
286 		tty_buffer_request_room(tty, actual_length);
287 		tty_insert_flip_string(tty, data, actual_length);
288 		tty_flip_buffer_push(tty);
289 	}
290 }
291 
292 
293 /******************************************************************************
294  * packet queue handling
295  ******************************************************************************/
296 
297 /*
298  * queue a received (usb-)packet for later processing
299  */
300 static int pkt_add(struct garmin_data *garmin_data_p,
301 		   unsigned char *data, unsigned int data_length)
302 {
303 	int state = 0;
304 	int result = 0;
305 	unsigned long flags;
306 	struct garmin_packet *pkt;
307 
308 	/* process only packets containg data ... */
309 	if (data_length) {
310 		pkt = kmalloc(sizeof(struct garmin_packet)+data_length,
311 								GFP_ATOMIC);
312 		if (pkt == NULL) {
313 			dev_err(&garmin_data_p->port->dev, "out of memory\n");
314 			return 0;
315 		}
316 		pkt->size = data_length;
317 		memcpy(pkt->data, data, data_length);
318 
319 		spin_lock_irqsave(&garmin_data_p->lock, flags);
320 		garmin_data_p->flags |= FLAGS_QUEUING;
321 		result = list_empty(&garmin_data_p->pktlist);
322 		pkt->seq = garmin_data_p->seq_counter++;
323 		list_add_tail(&pkt->list, &garmin_data_p->pktlist);
324 		state = garmin_data_p->state;
325 		spin_unlock_irqrestore(&garmin_data_p->lock, flags);
326 
327 		/* in serial mode, if someone is waiting for data from
328 		   the device, iconvert and send the next packet to tty. */
329 		if (result && (state == STATE_GSP_WAIT_DATA))
330 			gsp_next_packet(garmin_data_p);
331 	}
332 	return result;
333 }
334 
335 
336 /* get the next pending packet */
337 static struct garmin_packet *pkt_pop(struct garmin_data *garmin_data_p)
338 {
339 	unsigned long flags;
340 	struct garmin_packet *result = NULL;
341 
342 	spin_lock_irqsave(&garmin_data_p->lock, flags);
343 	if (!list_empty(&garmin_data_p->pktlist)) {
344 		result = (struct garmin_packet *)garmin_data_p->pktlist.next;
345 		list_del(&result->list);
346 	}
347 	spin_unlock_irqrestore(&garmin_data_p->lock, flags);
348 	return result;
349 }
350 
351 
352 /* free up all queued data */
353 static void pkt_clear(struct garmin_data *garmin_data_p)
354 {
355 	unsigned long flags;
356 	struct garmin_packet *result = NULL;
357 
358 	dbg("%s", __func__);
359 
360 	spin_lock_irqsave(&garmin_data_p->lock, flags);
361 	while (!list_empty(&garmin_data_p->pktlist)) {
362 		result = (struct garmin_packet *)garmin_data_p->pktlist.next;
363 		list_del(&result->list);
364 		kfree(result);
365 	}
366 	spin_unlock_irqrestore(&garmin_data_p->lock, flags);
367 }
368 
369 
370 /******************************************************************************
371  * garmin serial protocol handling handling
372  ******************************************************************************/
373 
374 /* send an ack packet back to the tty */
375 static int gsp_send_ack(struct garmin_data *garmin_data_p, __u8 pkt_id)
376 {
377 	__u8 pkt[10];
378 	__u8 cksum = 0;
379 	__u8 *ptr = pkt;
380 	unsigned  l = 0;
381 
382 	dbg("%s - pkt-id: 0x%X.", __func__, 0xFF & pkt_id);
383 
384 	*ptr++ = DLE;
385 	*ptr++ = ACK;
386 	cksum += ACK;
387 
388 	*ptr++ = 2;
389 	cksum += 2;
390 
391 	*ptr++ = pkt_id;
392 	cksum += pkt_id;
393 
394 	if (pkt_id == DLE)
395 		*ptr++ = DLE;
396 
397 	*ptr++ = 0;
398 	*ptr++ = 0xFF & (-cksum);
399 	*ptr++ = DLE;
400 	*ptr++ = ETX;
401 
402 	l = ptr-pkt;
403 
404 	send_to_tty(garmin_data_p->port, pkt, l);
405 	return 0;
406 }
407 
408 
409 
410 /*
411  * called for a complete packet received from tty layer
412  *
413  * the complete packet (pkzid ... cksum) is in garmin_data_p->inbuf starting
414  * at GSP_INITIAL_OFFSET.
415  *
416  * count - number of bytes in the input buffer including space reserved for
417  *         the usb header: GSP_INITIAL_OFFSET + number of bytes in packet
418  *         (including pkt-id, data-length a. cksum)
419  */
420 static int gsp_rec_packet(struct garmin_data *garmin_data_p, int count)
421 {
422 	const __u8 *recpkt = garmin_data_p->inbuffer+GSP_INITIAL_OFFSET;
423 	__le32 *usbdata = (__le32 *) garmin_data_p->inbuffer;
424 
425 	int cksum = 0;
426 	int n = 0;
427 	int pktid = recpkt[0];
428 	int size = recpkt[1];
429 
430 	usb_serial_debug_data(debug, &garmin_data_p->port->dev,
431 			       __func__, count-GSP_INITIAL_OFFSET, recpkt);
432 
433 	if (size != (count-GSP_INITIAL_OFFSET-3)) {
434 		dbg("%s - invalid size, expected %d bytes, got %d",
435 			__func__, size, (count-GSP_INITIAL_OFFSET-3));
436 		return -EINVPKT;
437 	}
438 
439 	cksum += *recpkt++;
440 	cksum += *recpkt++;
441 
442 	/* sanity check, remove after test ... */
443 	if ((__u8 *)&(usbdata[3]) != recpkt) {
444 		dbg("%s - ptr mismatch %p - %p",
445 			__func__, &(usbdata[4]), recpkt);
446 		return -EINVPKT;
447 	}
448 
449 	while (n < size) {
450 		cksum += *recpkt++;
451 		n++;
452 	}
453 
454 	if ((0xff & (cksum + *recpkt)) != 0) {
455 		dbg("%s - invalid checksum, expected %02x, got %02x",
456 			__func__, 0xff & -cksum, 0xff & *recpkt);
457 		return -EINVPKT;
458 	}
459 
460 	usbdata[0] = __cpu_to_le32(GARMIN_LAYERID_APPL);
461 	usbdata[1] = __cpu_to_le32(pktid);
462 	usbdata[2] = __cpu_to_le32(size);
463 
464 	garmin_write_bulk(garmin_data_p->port, garmin_data_p->inbuffer,
465 			   GARMIN_PKTHDR_LENGTH+size, 0);
466 
467 	/* if this was an abort-transfer command, flush all
468 	   queued data. */
469 	if (isAbortTrfCmnd(garmin_data_p->inbuffer)) {
470 		garmin_data_p->flags |= FLAGS_DROP_DATA;
471 		pkt_clear(garmin_data_p);
472 	}
473 
474 	return count;
475 }
476 
477 
478 
479 /*
480  * Called for data received from tty
481  *
482  * buf contains the data read, it may span more than one packet or even
483  * incomplete packets
484  *
485  * input record should be a serial-record, but it may not be complete.
486  * Copy it into our local buffer, until an etx is seen (or an error
487  * occurs).
488  * Once the record is complete, convert into a usb packet and send it
489  * to the bulk pipe, send an ack back to the tty.
490  *
491  * If the input is an ack, just send the last queued packet to the
492  * tty layer.
493  *
494  * if the input is an abort command, drop all queued data.
495  */
496 
497 static int gsp_receive(struct garmin_data *garmin_data_p,
498 		       const unsigned char *buf, int count)
499 {
500 	unsigned long flags;
501 	int offs = 0;
502 	int ack_or_nak_seen = 0;
503 	int i = 0;
504 	__u8 *dest;
505 	int size;
506 	/* dleSeen: set if last byte read was a DLE */
507 	int dleSeen;
508 	/* skip: if set, skip incoming data until possible start of
509 	 *       new packet
510 	 */
511 	int skip;
512 	__u8 data;
513 
514 	spin_lock_irqsave(&garmin_data_p->lock, flags);
515 	dest = garmin_data_p->inbuffer;
516 	size = garmin_data_p->insize;
517 	dleSeen = garmin_data_p->flags & FLAGS_GSP_DLESEEN;
518 	skip = garmin_data_p->flags & FLAGS_GSP_SKIP;
519 	spin_unlock_irqrestore(&garmin_data_p->lock, flags);
520 
521 	dbg("%s - dle=%d skip=%d size=%d count=%d",
522 		__func__, dleSeen, skip, size, count);
523 
524 	if (size == 0)
525 		size = GSP_INITIAL_OFFSET;
526 
527 	while (offs < count) {
528 
529 		data = *(buf+offs);
530 		offs++;
531 
532 		if (data == DLE) {
533 			if (skip) { /* start of a new pkt */
534 				skip = 0;
535 				size = GSP_INITIAL_OFFSET;
536 				dleSeen = 1;
537 			} else if (dleSeen) {
538 				dest[size++] = data;
539 				dleSeen = 0;
540 			} else {
541 				dleSeen = 1;
542 			}
543 		} else if (data == ETX) {
544 			if (dleSeen) {
545 				/* packet complete */
546 
547 				data = dest[GSP_INITIAL_OFFSET];
548 
549 				if (data == ACK) {
550 					ack_or_nak_seen = ACK;
551 					dbg("ACK packet complete.");
552 				} else if (data == NAK) {
553 					ack_or_nak_seen = NAK;
554 					dbg("NAK packet complete.");
555 				} else {
556 					dbg("packet complete - id=0x%X.",
557 						0xFF & data);
558 					gsp_rec_packet(garmin_data_p, size);
559 				}
560 
561 				skip = 1;
562 				size = GSP_INITIAL_OFFSET;
563 				dleSeen = 0;
564 			} else {
565 				dest[size++] = data;
566 			}
567 		} else if (!skip) {
568 
569 			if (dleSeen) {
570 				dbg("non-masked DLE at %d - restarting", i);
571 				size = GSP_INITIAL_OFFSET;
572 				dleSeen = 0;
573 			}
574 
575 			dest[size++] = data;
576 		}
577 
578 		if (size >= GPS_IN_BUFSIZ) {
579 			dbg("%s - packet too large.", __func__);
580 			skip = 1;
581 			size = GSP_INITIAL_OFFSET;
582 			dleSeen = 0;
583 		}
584 	}
585 
586 	spin_lock_irqsave(&garmin_data_p->lock, flags);
587 
588 	garmin_data_p->insize = size;
589 
590 	/* copy flags back to structure */
591 	if (skip)
592 		garmin_data_p->flags |= FLAGS_GSP_SKIP;
593 	else
594 		garmin_data_p->flags &= ~FLAGS_GSP_SKIP;
595 
596 	if (dleSeen)
597 		garmin_data_p->flags |= FLAGS_GSP_DLESEEN;
598 	else
599 		garmin_data_p->flags &= ~FLAGS_GSP_DLESEEN;
600 
601 	if (ack_or_nak_seen)
602 		garmin_data_p->state = STATE_GSP_WAIT_DATA;
603 
604 	spin_unlock_irqrestore(&garmin_data_p->lock, flags);
605 
606 	if (ack_or_nak_seen)
607 		gsp_next_packet(garmin_data_p);
608 	return count;
609 }
610 
611 
612 
613 
614 /*
615  * Sends a usb packet to the tty
616  *
617  * Assumes, that all packages and at an usb-packet boundary.
618  *
619  * return <0 on error, 0 if packet is incomplete or > 0 if packet was sent
620  */
621 static int gsp_send(struct garmin_data *garmin_data_p,
622 		    const unsigned char *buf, int count)
623 {
624 	const unsigned char *src;
625 	unsigned char *dst;
626 	int pktid = 0;
627 	int datalen = 0;
628 	int cksum = 0;
629 	int i = 0;
630 	int k;
631 
632 	dbg("%s - state %d - %d bytes.", __func__,
633 					garmin_data_p->state, count);
634 
635 	k = garmin_data_p->outsize;
636 	if ((k+count) > GPS_OUT_BUFSIZ) {
637 		dbg("packet too large");
638 		garmin_data_p->outsize = 0;
639 		return -4;
640 	}
641 
642 	memcpy(garmin_data_p->outbuffer+k, buf, count);
643 	k += count;
644 	garmin_data_p->outsize = k;
645 
646 	if (k >= GARMIN_PKTHDR_LENGTH) {
647 		pktid  = getPacketId(garmin_data_p->outbuffer);
648 		datalen = getDataLength(garmin_data_p->outbuffer);
649 		i = GARMIN_PKTHDR_LENGTH + datalen;
650 		if (k < i)
651 			return 0;
652 	} else {
653 		return 0;
654 	}
655 
656 	dbg("%s - %d bytes in buffer, %d bytes in pkt.", __func__, k, i);
657 
658 	/* garmin_data_p->outbuffer now contains a complete packet */
659 
660 	usb_serial_debug_data(debug, &garmin_data_p->port->dev,
661 				__func__, k, garmin_data_p->outbuffer);
662 
663 	garmin_data_p->outsize = 0;
664 
665 	if (GARMIN_LAYERID_APPL != getLayerId(garmin_data_p->outbuffer)) {
666 		dbg("not an application packet (%d)",
667 				getLayerId(garmin_data_p->outbuffer));
668 		return -1;
669 	}
670 
671 	if (pktid > 255) {
672 		dbg("packet-id %d too large", pktid);
673 		return -2;
674 	}
675 
676 	if (datalen > 255) {
677 		dbg("packet-size %d too large", datalen);
678 		return -3;
679 	}
680 
681 	/* the serial protocol should be able to handle this packet */
682 
683 	k = 0;
684 	src = garmin_data_p->outbuffer+GARMIN_PKTHDR_LENGTH;
685 	for (i = 0; i < datalen; i++) {
686 		if (*src++ == DLE)
687 			k++;
688 	}
689 
690 	src = garmin_data_p->outbuffer+GARMIN_PKTHDR_LENGTH;
691 	if (k > (GARMIN_PKTHDR_LENGTH-2)) {
692 		/* can't add stuffing DLEs in place, move data to end
693 		   of buffer ... */
694 		dst = garmin_data_p->outbuffer+GPS_OUT_BUFSIZ-datalen;
695 		memcpy(dst, src, datalen);
696 		src = dst;
697 	}
698 
699 	dst = garmin_data_p->outbuffer;
700 
701 	*dst++ = DLE;
702 	*dst++ = pktid;
703 	cksum += pktid;
704 	*dst++ = datalen;
705 	cksum += datalen;
706 	if (datalen == DLE)
707 		*dst++ = DLE;
708 
709 	for (i = 0; i < datalen; i++) {
710 		__u8 c = *src++;
711 		*dst++ = c;
712 		cksum += c;
713 		if (c == DLE)
714 			*dst++ = DLE;
715 	}
716 
717 	cksum = 0xFF & -cksum;
718 	*dst++ = cksum;
719 	if (cksum == DLE)
720 		*dst++ = DLE;
721 	*dst++ = DLE;
722 	*dst++ = ETX;
723 
724 	i = dst-garmin_data_p->outbuffer;
725 
726 	send_to_tty(garmin_data_p->port, garmin_data_p->outbuffer, i);
727 
728 	garmin_data_p->pkt_id = pktid;
729 	garmin_data_p->state  = STATE_WAIT_TTY_ACK;
730 
731 	return i;
732 }
733 
734 
735 
736 
737 
738 /*
739  * Process the next pending data packet - if there is one
740  */
741 static void gsp_next_packet(struct garmin_data *garmin_data_p)
742 {
743 	struct garmin_packet *pkt = NULL;
744 
745 	while ((pkt = pkt_pop(garmin_data_p)) != NULL) {
746 		dbg("%s - next pkt: %d", __func__, pkt->seq);
747 		if (gsp_send(garmin_data_p, pkt->data, pkt->size) > 0) {
748 			kfree(pkt);
749 			return;
750 		}
751 		kfree(pkt);
752 	}
753 }
754 
755 
756 
757 
758 /******************************************************************************
759  * garmin native mode
760  ******************************************************************************/
761 
762 
763 /*
764  * Called for data received from tty
765  *
766  * The input data is expected to be in garmin usb-packet format.
767  *
768  * buf contains the data read, it may span more than one packet
769  * or even incomplete packets
770  */
771 static int nat_receive(struct garmin_data *garmin_data_p,
772 		       const unsigned char *buf, int count)
773 {
774 	unsigned long flags;
775 	__u8 *dest;
776 	int offs = 0;
777 	int result = count;
778 	int len;
779 
780 	while (offs < count) {
781 		/* if buffer contains header, copy rest of data */
782 		if (garmin_data_p->insize >= GARMIN_PKTHDR_LENGTH)
783 			len = GARMIN_PKTHDR_LENGTH
784 			      +getDataLength(garmin_data_p->inbuffer);
785 		else
786 			len = GARMIN_PKTHDR_LENGTH;
787 
788 		if (len >= GPS_IN_BUFSIZ) {
789 			/* seems to be an invalid packet, ignore rest
790 			   of input */
791 			dbg("%s - packet size too large: %d", __func__, len);
792 			garmin_data_p->insize = 0;
793 			count = 0;
794 			result = -EINVPKT;
795 		} else {
796 			len -= garmin_data_p->insize;
797 			if (len > (count-offs))
798 				len = (count-offs);
799 			if (len > 0) {
800 				dest = garmin_data_p->inbuffer
801 						+ garmin_data_p->insize;
802 				memcpy(dest, buf+offs, len);
803 				garmin_data_p->insize += len;
804 				offs += len;
805 			}
806 		}
807 
808 		/* do we have a complete packet ? */
809 		if (garmin_data_p->insize >= GARMIN_PKTHDR_LENGTH) {
810 			len = GARMIN_PKTHDR_LENGTH+
811 			   getDataLength(garmin_data_p->inbuffer);
812 			if (garmin_data_p->insize >= len) {
813 				garmin_write_bulk(garmin_data_p->port,
814 						   garmin_data_p->inbuffer,
815 						   len, 0);
816 				garmin_data_p->insize = 0;
817 
818 				/* if this was an abort-transfer command,
819 				   flush all queued data. */
820 				if (isAbortTrfCmnd(garmin_data_p->inbuffer)) {
821 					spin_lock_irqsave(&garmin_data_p->lock,
822 									flags);
823 					garmin_data_p->flags |= FLAGS_DROP_DATA;
824 					spin_unlock_irqrestore(
825 						&garmin_data_p->lock, flags);
826 					pkt_clear(garmin_data_p);
827 				}
828 			}
829 		}
830 	}
831 	return result;
832 }
833 
834 
835 /******************************************************************************
836  * private packets
837  ******************************************************************************/
838 
839 static void priv_status_resp(struct usb_serial_port *port)
840 {
841 	struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
842 	__le32 *pkt = (__le32 *)garmin_data_p->privpkt;
843 
844 	pkt[0] = __cpu_to_le32(GARMIN_LAYERID_PRIVATE);
845 	pkt[1] = __cpu_to_le32(PRIV_PKTID_INFO_RESP);
846 	pkt[2] = __cpu_to_le32(12);
847 	pkt[3] = __cpu_to_le32(VERSION_MAJOR << 16 | VERSION_MINOR);
848 	pkt[4] = __cpu_to_le32(garmin_data_p->mode);
849 	pkt[5] = __cpu_to_le32(garmin_data_p->serial_num);
850 
851 	send_to_tty(port, (__u8 *)pkt, 6 * 4);
852 }
853 
854 
855 /******************************************************************************
856  * Garmin specific driver functions
857  ******************************************************************************/
858 
859 static int process_resetdev_request(struct usb_serial_port *port)
860 {
861 	unsigned long flags;
862 	int status;
863 	struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
864 
865 	spin_lock_irqsave(&garmin_data_p->lock, flags);
866 	garmin_data_p->flags &= ~(CLEAR_HALT_REQUIRED);
867 	garmin_data_p->state = STATE_RESET;
868 	garmin_data_p->serial_num = 0;
869 	spin_unlock_irqrestore(&garmin_data_p->lock, flags);
870 
871 	usb_kill_urb(port->interrupt_in_urb);
872 	dbg("%s - usb_reset_device", __func__);
873 	status = usb_reset_device(port->serial->dev);
874 	if (status)
875 		dbg("%s - usb_reset_device failed: %d",
876 			__func__, status);
877 	return status;
878 }
879 
880 
881 
882 /*
883  * clear all cached data
884  */
885 static int garmin_clear(struct garmin_data *garmin_data_p)
886 {
887 	unsigned long flags;
888 	int status = 0;
889 
890 	struct usb_serial_port *port = garmin_data_p->port;
891 
892 	if (port != NULL && atomic_read(&garmin_data_p->resp_count)) {
893 		/* send a terminate command */
894 		status = garmin_write_bulk(port, GARMIN_STOP_TRANSFER_REQ,
895 					sizeof(GARMIN_STOP_TRANSFER_REQ), 1);
896 	}
897 
898 	/* flush all queued data */
899 	pkt_clear(garmin_data_p);
900 
901 	spin_lock_irqsave(&garmin_data_p->lock, flags);
902 	garmin_data_p->insize = 0;
903 	garmin_data_p->outsize = 0;
904 	spin_unlock_irqrestore(&garmin_data_p->lock, flags);
905 
906 	return status;
907 }
908 
909 
910 
911 
912 
913 
914 static int garmin_init_session(struct usb_serial_port *port)
915 {
916 	unsigned long flags;
917 	struct usb_serial *serial = port->serial;
918 	struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
919 	int status = 0;
920 
921 	if (status == 0) {
922 		usb_kill_urb(port->interrupt_in_urb);
923 
924 		dbg("%s - adding interrupt input", __func__);
925 		port->interrupt_in_urb->dev = serial->dev;
926 		status = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
927 		if (status)
928 			dev_err(&serial->dev->dev,
929 			  "%s - failed submitting interrupt urb, error %d\n",
930 							__func__, status);
931 	}
932 
933 	if (status == 0) {
934 		dbg("%s - starting session ...", __func__);
935 		garmin_data_p->state = STATE_ACTIVE;
936 		status = garmin_write_bulk(port, GARMIN_START_SESSION_REQ,
937 					sizeof(GARMIN_START_SESSION_REQ), 0);
938 
939 		if (status >= 0) {
940 
941 			spin_lock_irqsave(&garmin_data_p->lock, flags);
942 			garmin_data_p->ignorePkts++;
943 			spin_unlock_irqrestore(&garmin_data_p->lock, flags);
944 
945 			/* not needed, but the win32 driver does it too ... */
946 			status = garmin_write_bulk(port,
947 					GARMIN_START_SESSION_REQ2,
948 					sizeof(GARMIN_START_SESSION_REQ2), 0);
949 			if (status >= 0) {
950 				status = 0;
951 				spin_lock_irqsave(&garmin_data_p->lock, flags);
952 				garmin_data_p->ignorePkts++;
953 				spin_unlock_irqrestore(&garmin_data_p->lock,
954 									flags);
955 			}
956 		}
957 	}
958 
959 	return status;
960 }
961 
962 
963 
964 
965 
966 static int garmin_open(struct tty_struct *tty,
967 			struct usb_serial_port *port, struct file *filp)
968 {
969 	unsigned long flags;
970 	int status = 0;
971 	struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
972 
973 	dbg("%s - port %d", __func__, port->number);
974 
975 	/*
976 	 * Force low_latency on so that our tty_push actually forces the data
977 	 * through, otherwise it is scheduled, and with high data rates (like
978 	 * with OHCI) data can get lost.
979 	 */
980 	if (tty)
981 		tty->low_latency = 1;
982 
983 	spin_lock_irqsave(&garmin_data_p->lock, flags);
984 	garmin_data_p->mode  = initial_mode;
985 	garmin_data_p->count = 0;
986 	garmin_data_p->flags = 0;
987 	atomic_set(&garmin_data_p->req_count, 0);
988 	atomic_set(&garmin_data_p->resp_count, 0);
989 	spin_unlock_irqrestore(&garmin_data_p->lock, flags);
990 
991 	/* shutdown any bulk reads that might be going on */
992 	usb_kill_urb(port->write_urb);
993 	usb_kill_urb(port->read_urb);
994 
995 	if (garmin_data_p->state == STATE_RESET)
996 		status = garmin_init_session(port);
997 
998 	garmin_data_p->state = STATE_ACTIVE;
999 	return status;
1000 }
1001 
1002 
1003 static void garmin_close(struct tty_struct *tty,
1004 			struct usb_serial_port *port, struct file *filp)
1005 {
1006 	struct usb_serial *serial = port->serial;
1007 	struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1008 
1009 	dbg("%s - port %d - mode=%d state=%d flags=0x%X", __func__,
1010 		port->number, garmin_data_p->mode,
1011 		garmin_data_p->state, garmin_data_p->flags);
1012 
1013 	if (!serial)
1014 		return;
1015 
1016 	mutex_lock(&port->serial->disc_mutex);
1017 	if (!port->serial->disconnected)
1018 		garmin_clear(garmin_data_p);
1019 
1020 	/* shutdown our urbs */
1021 	usb_kill_urb(port->read_urb);
1022 	usb_kill_urb(port->write_urb);
1023 
1024 	if (!port->serial->disconnected) {
1025 		if (noResponseFromAppLayer(garmin_data_p) ||
1026 		    ((garmin_data_p->flags & CLEAR_HALT_REQUIRED) != 0)) {
1027 			process_resetdev_request(port);
1028 			garmin_data_p->state = STATE_RESET;
1029 		} else {
1030 			garmin_data_p->state = STATE_DISCONNECTED;
1031 		}
1032 	} else {
1033 		garmin_data_p->state = STATE_DISCONNECTED;
1034 	}
1035 	mutex_unlock(&port->serial->disc_mutex);
1036 }
1037 
1038 static void garmin_write_bulk_callback(struct urb *urb)
1039 {
1040 	unsigned long flags;
1041 	struct usb_serial_port *port = urb->context;
1042 	int status = urb->status;
1043 
1044 	if (port) {
1045 		struct garmin_data *garmin_data_p =
1046 					usb_get_serial_port_data(port);
1047 
1048 		dbg("%s - port %d", __func__, port->number);
1049 
1050 		if (GARMIN_LAYERID_APPL == getLayerId(urb->transfer_buffer)
1051 		    && (garmin_data_p->mode == MODE_GARMIN_SERIAL))  {
1052 			gsp_send_ack(garmin_data_p,
1053 					((__u8 *)urb->transfer_buffer)[4]);
1054 		}
1055 
1056 		if (status) {
1057 			dbg("%s - nonzero write bulk status received: %d",
1058 			    __func__, urb->status);
1059 			spin_lock_irqsave(&garmin_data_p->lock, flags);
1060 			garmin_data_p->flags |= CLEAR_HALT_REQUIRED;
1061 			spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1062 		}
1063 
1064 		usb_serial_port_softint(port);
1065 	}
1066 
1067 	/* Ignore errors that resulted from garmin_write_bulk with
1068 	   dismiss_ack = 1 */
1069 
1070 	/* free up the transfer buffer, as usb_free_urb() does not do this */
1071 	kfree(urb->transfer_buffer);
1072 }
1073 
1074 
1075 static int garmin_write_bulk(struct usb_serial_port *port,
1076 			      const unsigned char *buf, int count,
1077 			      int dismiss_ack)
1078 {
1079 	unsigned long flags;
1080 	struct usb_serial *serial = port->serial;
1081 	struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1082 	struct urb *urb;
1083 	unsigned char *buffer;
1084 	int status;
1085 
1086 	dbg("%s - port %d, state %d", __func__, port->number,
1087 		garmin_data_p->state);
1088 
1089 	spin_lock_irqsave(&garmin_data_p->lock, flags);
1090 	garmin_data_p->flags &= ~FLAGS_DROP_DATA;
1091 	spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1092 
1093 	buffer = kmalloc(count, GFP_ATOMIC);
1094 	if (!buffer) {
1095 		dev_err(&port->dev, "out of memory\n");
1096 		return -ENOMEM;
1097 	}
1098 
1099 	urb = usb_alloc_urb(0, GFP_ATOMIC);
1100 	if (!urb) {
1101 		dev_err(&port->dev, "no more free urbs\n");
1102 		kfree(buffer);
1103 		return -ENOMEM;
1104 	}
1105 
1106 	memcpy(buffer, buf, count);
1107 
1108 	usb_serial_debug_data(debug, &port->dev, __func__, count, buffer);
1109 
1110 	usb_fill_bulk_urb(urb, serial->dev,
1111 				usb_sndbulkpipe(serial->dev,
1112 					port->bulk_out_endpointAddress),
1113 				buffer, count,
1114 				garmin_write_bulk_callback,
1115 				dismiss_ack ? NULL : port);
1116 	urb->transfer_flags |= URB_ZERO_PACKET;
1117 
1118 	if (GARMIN_LAYERID_APPL == getLayerId(buffer)) {
1119 		atomic_inc(&garmin_data_p->req_count);
1120 		if (garmin_data_p->mode == MODE_GARMIN_SERIAL)  {
1121 			pkt_clear(garmin_data_p);
1122 			garmin_data_p->state = STATE_GSP_WAIT_DATA;
1123 		}
1124 	}
1125 
1126 	/* send it down the pipe */
1127 	status = usb_submit_urb(urb, GFP_ATOMIC);
1128 	if (status) {
1129 		dev_err(&port->dev,
1130 		   "%s - usb_submit_urb(write bulk) failed with status = %d\n",
1131 				__func__, status);
1132 		count = status;
1133 	}
1134 
1135 	/* we are done with this urb, so let the host driver
1136 	 * really free it when it is finished with it */
1137 	usb_free_urb(urb);
1138 
1139 	return count;
1140 }
1141 
1142 static int garmin_write(struct tty_struct *tty, struct usb_serial_port *port,
1143 					 const unsigned char *buf, int count)
1144 {
1145 	int pktid, pktsiz, len;
1146 	struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1147 	__le32 *privpkt = (__le32 *)garmin_data_p->privpkt;
1148 
1149 	usb_serial_debug_data(debug, &port->dev, __func__, count, buf);
1150 
1151 	/* check for our private packets */
1152 	if (count >= GARMIN_PKTHDR_LENGTH) {
1153 		len = PRIVPKTSIZ;
1154 		if (count < len)
1155 			len = count;
1156 
1157 		memcpy(garmin_data_p->privpkt, buf, len);
1158 
1159 		pktsiz = getDataLength(garmin_data_p->privpkt);
1160 		pktid  = getPacketId(garmin_data_p->privpkt);
1161 
1162 		if (count == (GARMIN_PKTHDR_LENGTH+pktsiz)
1163 		    && GARMIN_LAYERID_PRIVATE ==
1164 				getLayerId(garmin_data_p->privpkt)) {
1165 
1166 			dbg("%s - processing private request %d",
1167 				__func__, pktid);
1168 
1169 			/* drop all unfinished transfers */
1170 			garmin_clear(garmin_data_p);
1171 
1172 			switch (pktid) {
1173 
1174 			case PRIV_PKTID_SET_DEBUG:
1175 				if (pktsiz != 4)
1176 					return -EINVPKT;
1177 				debug = __le32_to_cpu(privpkt[3]);
1178 				dbg("%s - debug level set to 0x%X",
1179 					__func__, debug);
1180 				break;
1181 
1182 			case PRIV_PKTID_SET_MODE:
1183 				if (pktsiz != 4)
1184 					return -EINVPKT;
1185 				garmin_data_p->mode = __le32_to_cpu(privpkt[3]);
1186 				dbg("%s - mode set to %d",
1187 					__func__, garmin_data_p->mode);
1188 				break;
1189 
1190 			case PRIV_PKTID_INFO_REQ:
1191 				priv_status_resp(port);
1192 				break;
1193 
1194 			case PRIV_PKTID_RESET_REQ:
1195 				atomic_inc(&garmin_data_p->req_count);
1196 				break;
1197 
1198 			case PRIV_PKTID_SET_DEF_MODE:
1199 				if (pktsiz != 4)
1200 					return -EINVPKT;
1201 				initial_mode = __le32_to_cpu(privpkt[3]);
1202 				dbg("%s - initial_mode set to %d",
1203 					__func__,
1204 					garmin_data_p->mode);
1205 				break;
1206 			}
1207 			return count;
1208 		}
1209 	}
1210 
1211 	garmin_data_p->ignorePkts = 0;
1212 
1213 	if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
1214 		return gsp_receive(garmin_data_p, buf, count);
1215 	} else {	/* MODE_NATIVE */
1216 		return nat_receive(garmin_data_p, buf, count);
1217 	}
1218 }
1219 
1220 
1221 static int garmin_write_room(struct tty_struct *tty)
1222 {
1223 	struct usb_serial_port *port = tty->driver_data;
1224 	/*
1225 	 * Report back the bytes currently available in the output buffer.
1226 	 */
1227 	struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1228 	return GPS_OUT_BUFSIZ-garmin_data_p->outsize;
1229 }
1230 
1231 
1232 static void garmin_read_process(struct garmin_data *garmin_data_p,
1233 				 unsigned char *data, unsigned data_length)
1234 {
1235 	if (garmin_data_p->flags & FLAGS_DROP_DATA) {
1236 		/* abort-transfer cmd is actice */
1237 		dbg("%s - pkt dropped", __func__);
1238 	} else if (garmin_data_p->state != STATE_DISCONNECTED &&
1239 		garmin_data_p->state != STATE_RESET) {
1240 
1241 		/* remember any appl.layer packets, so we know
1242 		   if a reset is required or not when closing
1243 		   the device */
1244 		if (0 == memcmp(data, GARMIN_APP_LAYER_REPLY,
1245 				sizeof(GARMIN_APP_LAYER_REPLY))) {
1246 			atomic_inc(&garmin_data_p->resp_count);
1247 		}
1248 
1249 		/* if throttling is active or postprecessing is required
1250 		   put the received data in the input queue, otherwise
1251 		   send it directly to the tty port */
1252 		if (garmin_data_p->flags & FLAGS_QUEUING) {
1253 			pkt_add(garmin_data_p, data, data_length);
1254 		} else if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
1255 			if (getLayerId(data) == GARMIN_LAYERID_APPL)
1256 				pkt_add(garmin_data_p, data, data_length);
1257 		} else {
1258 			send_to_tty(garmin_data_p->port, data, data_length);
1259 		}
1260 	}
1261 }
1262 
1263 
1264 static void garmin_read_bulk_callback(struct urb *urb)
1265 {
1266 	unsigned long flags;
1267 	struct usb_serial_port *port = urb->context;
1268 	struct usb_serial *serial =  port->serial;
1269 	struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1270 	unsigned char *data = urb->transfer_buffer;
1271 	int status = urb->status;
1272 	int retval;
1273 
1274 	dbg("%s - port %d", __func__, port->number);
1275 
1276 	if (!serial) {
1277 		dbg("%s - bad serial pointer, exiting", __func__);
1278 		return;
1279 	}
1280 
1281 	if (status) {
1282 		dbg("%s - nonzero read bulk status received: %d",
1283 			__func__, status);
1284 		return;
1285 	}
1286 
1287 	usb_serial_debug_data(debug, &port->dev,
1288 				__func__, urb->actual_length, data);
1289 
1290 	garmin_read_process(garmin_data_p, data, urb->actual_length);
1291 
1292 	if (urb->actual_length == 0 &&
1293 			0 != (garmin_data_p->flags & FLAGS_BULK_IN_RESTART)) {
1294 		spin_lock_irqsave(&garmin_data_p->lock, flags);
1295 		garmin_data_p->flags &= ~FLAGS_BULK_IN_RESTART;
1296 		spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1297 		retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
1298 		if (retval)
1299 			dev_err(&port->dev,
1300 				"%s - failed resubmitting read urb, error %d\n",
1301 				__func__, retval);
1302 	} else if (urb->actual_length > 0) {
1303 		/* Continue trying to read until nothing more is received  */
1304 		if (0 == (garmin_data_p->flags & FLAGS_THROTTLED)) {
1305 			retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
1306 			if (retval)
1307 				dev_err(&port->dev,
1308 					"%s - failed resubmitting read urb, "
1309 					"error %d\n", __func__, retval);
1310 		}
1311 	} else {
1312 		dbg("%s - end of bulk data", __func__);
1313 		spin_lock_irqsave(&garmin_data_p->lock, flags);
1314 		garmin_data_p->flags &= ~FLAGS_BULK_IN_ACTIVE;
1315 		spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1316 	}
1317 	return;
1318 }
1319 
1320 
1321 static void garmin_read_int_callback(struct urb *urb)
1322 {
1323 	unsigned long flags;
1324 	int retval;
1325 	struct usb_serial_port *port = urb->context;
1326 	struct usb_serial *serial = port->serial;
1327 	struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1328 	unsigned char *data = urb->transfer_buffer;
1329 	int status = urb->status;
1330 
1331 	switch (status) {
1332 	case 0:
1333 		/* success */
1334 		break;
1335 	case -ECONNRESET:
1336 	case -ENOENT:
1337 	case -ESHUTDOWN:
1338 		/* this urb is terminated, clean up */
1339 		dbg("%s - urb shutting down with status: %d",
1340 			__func__, status);
1341 		return;
1342 	default:
1343 		dbg("%s - nonzero urb status received: %d",
1344 			__func__, status);
1345 		return;
1346 	}
1347 
1348 	usb_serial_debug_data(debug, &port->dev, __func__,
1349 				urb->actual_length, urb->transfer_buffer);
1350 
1351 	if (urb->actual_length == sizeof(GARMIN_BULK_IN_AVAIL_REPLY) &&
1352 	    0 == memcmp(data, GARMIN_BULK_IN_AVAIL_REPLY,
1353 				sizeof(GARMIN_BULK_IN_AVAIL_REPLY))) {
1354 
1355 		dbg("%s - bulk data available.", __func__);
1356 
1357 		if (0 == (garmin_data_p->flags & FLAGS_BULK_IN_ACTIVE)) {
1358 
1359 			/* bulk data available */
1360 			usb_fill_bulk_urb(port->read_urb, serial->dev,
1361 					usb_rcvbulkpipe(serial->dev,
1362 						port->bulk_in_endpointAddress),
1363 					port->read_urb->transfer_buffer,
1364 					port->read_urb->transfer_buffer_length,
1365 					garmin_read_bulk_callback, port);
1366 			retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
1367 			if (retval) {
1368 				dev_err(&port->dev,
1369 				 "%s - failed submitting read urb, error %d\n",
1370 							__func__, retval);
1371 			} else {
1372 				spin_lock_irqsave(&garmin_data_p->lock, flags);
1373 				garmin_data_p->flags |= FLAGS_BULK_IN_ACTIVE;
1374 				/* do not send this packet to the user */
1375 				garmin_data_p->ignorePkts = 1;
1376 				spin_unlock_irqrestore(&garmin_data_p->lock,
1377 									flags);
1378 			}
1379 		} else {
1380 			/* bulk-in transfer still active */
1381 			spin_lock_irqsave(&garmin_data_p->lock, flags);
1382 			garmin_data_p->flags |= FLAGS_BULK_IN_RESTART;
1383 			spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1384 		}
1385 
1386 	} else if (urb->actual_length == (4+sizeof(GARMIN_START_SESSION_REPLY))
1387 			 && 0 == memcmp(data, GARMIN_START_SESSION_REPLY,
1388 					sizeof(GARMIN_START_SESSION_REPLY))) {
1389 
1390 		spin_lock_irqsave(&garmin_data_p->lock, flags);
1391 		garmin_data_p->flags |= FLAGS_SESSION_REPLY1_SEEN;
1392 		spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1393 
1394 		/* save the serial number */
1395 		garmin_data_p->serial_num = __le32_to_cpup(
1396 					(__le32 *)(data+GARMIN_PKTHDR_LENGTH));
1397 
1398 		dbg("%s - start-of-session reply seen - serial %u.",
1399 			__func__, garmin_data_p->serial_num);
1400 	}
1401 
1402 	if (garmin_data_p->ignorePkts) {
1403 		/* this reply belongs to a request generated by the driver,
1404 		   ignore it. */
1405 		dbg("%s - pkt ignored (%d)",
1406 			__func__, garmin_data_p->ignorePkts);
1407 		spin_lock_irqsave(&garmin_data_p->lock, flags);
1408 		garmin_data_p->ignorePkts--;
1409 		spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1410 	} else {
1411 		garmin_read_process(garmin_data_p, data, urb->actual_length);
1412 	}
1413 
1414 	port->interrupt_in_urb->dev = port->serial->dev;
1415 	retval = usb_submit_urb(urb, GFP_ATOMIC);
1416 	if (retval)
1417 		dev_err(&urb->dev->dev,
1418 			"%s - Error %d submitting interrupt urb\n",
1419 			__func__, retval);
1420 }
1421 
1422 
1423 /*
1424  * Sends the next queued packt to the tty port (garmin native mode only)
1425  * and then sets a timer to call itself again until all queued data
1426  * is sent.
1427  */
1428 static int garmin_flush_queue(struct garmin_data *garmin_data_p)
1429 {
1430 	unsigned long flags;
1431 	struct garmin_packet *pkt;
1432 
1433 	if ((garmin_data_p->flags & FLAGS_THROTTLED) == 0) {
1434 		pkt = pkt_pop(garmin_data_p);
1435 		if (pkt != NULL) {
1436 			send_to_tty(garmin_data_p->port, pkt->data, pkt->size);
1437 			kfree(pkt);
1438 			mod_timer(&garmin_data_p->timer, (1)+jiffies);
1439 
1440 		} else {
1441 			spin_lock_irqsave(&garmin_data_p->lock, flags);
1442 			garmin_data_p->flags &= ~FLAGS_QUEUING;
1443 			spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1444 		}
1445 	}
1446 	return 0;
1447 }
1448 
1449 
1450 static void garmin_throttle(struct tty_struct *tty)
1451 {
1452 	struct usb_serial_port *port = tty->driver_data;
1453 	struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1454 	unsigned long flags;
1455 
1456 	dbg("%s - port %d", __func__, port->number);
1457 	/* set flag, data received will be put into a queue
1458 	   for later processing */
1459 	spin_lock_irqsave(&garmin_data_p->lock, flags);
1460 	garmin_data_p->flags |= FLAGS_QUEUING|FLAGS_THROTTLED;
1461 	spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1462 }
1463 
1464 
1465 static void garmin_unthrottle(struct tty_struct *tty)
1466 {
1467 	struct usb_serial_port *port = tty->driver_data;
1468 	struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1469 	unsigned long flags;
1470 	int status;
1471 
1472 	dbg("%s - port %d", __func__, port->number);
1473 	spin_lock_irqsave(&garmin_data_p->lock, flags);
1474 	garmin_data_p->flags &= ~FLAGS_THROTTLED;
1475 	spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1476 
1477 	/* in native mode send queued data to tty, in
1478 	   serial mode nothing needs to be done here */
1479 	if (garmin_data_p->mode == MODE_NATIVE)
1480 		garmin_flush_queue(garmin_data_p);
1481 
1482 	if (0 != (garmin_data_p->flags & FLAGS_BULK_IN_ACTIVE)) {
1483 		status = usb_submit_urb(port->read_urb, GFP_ATOMIC);
1484 		if (status)
1485 			dev_err(&port->dev,
1486 				"%s - failed resubmitting read urb, error %d\n",
1487 				__func__, status);
1488 	}
1489 }
1490 
1491 /*
1492  * The timer is currently only used to send queued packets to
1493  * the tty in cases where the protocol provides no own handshaking
1494  * to initiate the transfer.
1495  */
1496 static void timeout_handler(unsigned long data)
1497 {
1498 	struct garmin_data *garmin_data_p = (struct garmin_data *) data;
1499 
1500 	/* send the next queued packet to the tty port */
1501 	if (garmin_data_p->mode == MODE_NATIVE)
1502 		if (garmin_data_p->flags & FLAGS_QUEUING)
1503 			garmin_flush_queue(garmin_data_p);
1504 }
1505 
1506 
1507 
1508 static int garmin_attach(struct usb_serial *serial)
1509 {
1510 	int status = 0;
1511 	struct usb_serial_port *port = serial->port[0];
1512 	struct garmin_data *garmin_data_p = NULL;
1513 
1514 	dbg("%s", __func__);
1515 
1516 	garmin_data_p = kzalloc(sizeof(struct garmin_data), GFP_KERNEL);
1517 	if (garmin_data_p == NULL) {
1518 		dev_err(&port->dev, "%s - Out of memory\n", __func__);
1519 		return -ENOMEM;
1520 	}
1521 	init_timer(&garmin_data_p->timer);
1522 	spin_lock_init(&garmin_data_p->lock);
1523 	INIT_LIST_HEAD(&garmin_data_p->pktlist);
1524 	/* garmin_data_p->timer.expires = jiffies + session_timeout; */
1525 	garmin_data_p->timer.data = (unsigned long)garmin_data_p;
1526 	garmin_data_p->timer.function = timeout_handler;
1527 	garmin_data_p->port = port;
1528 	garmin_data_p->state = 0;
1529 	garmin_data_p->count = 0;
1530 	usb_set_serial_port_data(port, garmin_data_p);
1531 
1532 	status = garmin_init_session(port);
1533 
1534 	return status;
1535 }
1536 
1537 
1538 static void garmin_shutdown(struct usb_serial *serial)
1539 {
1540 	struct usb_serial_port *port = serial->port[0];
1541 	struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1542 
1543 	dbg("%s", __func__);
1544 
1545 	usb_kill_urb(port->interrupt_in_urb);
1546 	del_timer_sync(&garmin_data_p->timer);
1547 	kfree(garmin_data_p);
1548 	usb_set_serial_port_data(port, NULL);
1549 }
1550 
1551 
1552 /* All of the device info needed */
1553 static struct usb_serial_driver garmin_device = {
1554 	.driver = {
1555 		.owner       = THIS_MODULE,
1556 		.name        = "garmin_gps",
1557 	},
1558 	.description         = "Garmin GPS usb/tty",
1559 	.usb_driver          = &garmin_driver,
1560 	.id_table            = id_table,
1561 	.num_ports           = 1,
1562 	.open                = garmin_open,
1563 	.close               = garmin_close,
1564 	.throttle            = garmin_throttle,
1565 	.unthrottle          = garmin_unthrottle,
1566 	.attach              = garmin_attach,
1567 	.shutdown            = garmin_shutdown,
1568 	.write               = garmin_write,
1569 	.write_room          = garmin_write_room,
1570 	.write_bulk_callback = garmin_write_bulk_callback,
1571 	.read_bulk_callback  = garmin_read_bulk_callback,
1572 	.read_int_callback   = garmin_read_int_callback,
1573 };
1574 
1575 
1576 
1577 static int __init garmin_init(void)
1578 {
1579 	int retval;
1580 
1581 	retval = usb_serial_register(&garmin_device);
1582 	if (retval)
1583 		goto failed_garmin_register;
1584 	retval = usb_register(&garmin_driver);
1585 	if (retval)
1586 		goto failed_usb_register;
1587 	info(DRIVER_DESC " " DRIVER_VERSION);
1588 
1589 	return 0;
1590 failed_usb_register:
1591 	usb_serial_deregister(&garmin_device);
1592 failed_garmin_register:
1593 	return retval;
1594 }
1595 
1596 
1597 static void __exit garmin_exit(void)
1598 {
1599 	usb_deregister(&garmin_driver);
1600 	usb_serial_deregister(&garmin_device);
1601 }
1602 
1603 
1604 
1605 
1606 module_init(garmin_init);
1607 module_exit(garmin_exit);
1608 
1609 MODULE_AUTHOR(DRIVER_AUTHOR);
1610 MODULE_DESCRIPTION(DRIVER_DESC);
1611 MODULE_LICENSE("GPL");
1612 
1613 module_param(debug, bool, S_IWUSR | S_IRUGO);
1614 MODULE_PARM_DESC(debug, "Debug enabled or not");
1615 module_param(initial_mode, int, S_IRUGO);
1616 MODULE_PARM_DESC(initial_mode, "Initial mode");
1617 
1618