xref: /openbmc/linux/drivers/usb/serial/garmin_gps.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2  * Garmin GPS driver
3  *
4  * Copyright (C) 2004 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/config.h>
27 #include <linux/kernel.h>
28 #include <linux/errno.h>
29 #include <linux/init.h>
30 #include <linux/slab.h>
31 #include <linux/timer.h>
32 #include <linux/tty.h>
33 #include <linux/tty_driver.h>
34 #include <linux/tty_flip.h>
35 #include <linux/module.h>
36 #include <linux/spinlock.h>
37 #include <asm/uaccess.h>
38 #include <linux/usb.h>
39 
40 /* the mode to be set when the port ist opened */
41 static int initial_mode = 1;
42 
43 /* debug flag */
44 static int debug = 0;
45 
46 #include "usb-serial.h"
47 
48 #define GARMIN_VENDOR_ID             0x091E
49 
50 /*
51  * Version Information
52  */
53 
54 #define VERSION_MAJOR	0
55 #define VERSION_MINOR	23
56 
57 #define _STR(s) #s
58 #define _DRIVER_VERSION(a,b) "v" _STR(a) "." _STR(b)
59 #define DRIVER_VERSION _DRIVER_VERSION(VERSION_MAJOR, VERSION_MINOR)
60 #define DRIVER_AUTHOR "hermann kneissel"
61 #define DRIVER_DESC "garmin gps driver"
62 
63 /* error codes returned by the driver */
64 #define EINVPKT	1000	/* invalid packet structure */
65 
66 
67 // size of the header of a packet using the usb protocol
68 #define GARMIN_PKTHDR_LENGTH	12
69 
70 // max. possible size of a packet using the serial protocol
71 #define MAX_SERIAL_PKT_SIZ (3+255+3)
72 
73 // max. possible size of a packet with worst case stuffing
74 #define MAX_SERIAL_PKT_SIZ_STUFFED MAX_SERIAL_PKT_SIZ+256
75 
76 // size of a buffer able to hold a complete (no stuffing) packet
77 // (the document protocol does not contain packets with a larger
78 //  size, but in theory a packet may be 64k+12 bytes - if in
79 //  later protocol versions larger packet sizes occur, this value
80 //  should be increased accordingly, so the input buffer is always
81 //  large enough the store a complete packet inclusive header)
82 #define GPS_IN_BUFSIZ  (GARMIN_PKTHDR_LENGTH+MAX_SERIAL_PKT_SIZ)
83 
84 // size of a buffer able to hold a complete (incl. stuffing) packet
85 #define GPS_OUT_BUFSIZ (GARMIN_PKTHDR_LENGTH+MAX_SERIAL_PKT_SIZ_STUFFED)
86 
87 // where to place the packet id of a serial packet, so we can
88 // prepend the usb-packet header without the need to move the
89 // packets data
90 #define GSP_INITIAL_OFFSET (GARMIN_PKTHDR_LENGTH-2)
91 
92 // max. size of incoming private packets (header+1 param)
93 #define PRIVPKTSIZ (GARMIN_PKTHDR_LENGTH+4)
94 
95 #define GARMIN_LAYERID_TRANSPORT  0
96 #define GARMIN_LAYERID_APPL      20
97 // our own layer-id to use for some control mechanisms
98 #define GARMIN_LAYERID_PRIVATE	0x01106E4B
99 
100 #define GARMIN_PKTID_PVT_DATA	51
101 #define GARMIN_PKTID_L001_COMMAND_DATA 10
102 
103 #define CMND_ABORT_TRANSFER 0
104 
105 // packet ids used in private layer
106 #define PRIV_PKTID_SET_DEBUG	1
107 #define PRIV_PKTID_SET_MODE	2
108 #define PRIV_PKTID_INFO_REQ	3
109 #define PRIV_PKTID_INFO_RESP	4
110 #define PRIV_PKTID_RESET_REQ	5
111 #define PRIV_PKTID_SET_DEF_MODE	6
112 
113 
114 #define ETX	0x03
115 #define DLE	0x10
116 #define ACK	0x06
117 #define NAK	0x15
118 
119 /* structure used to queue incoming packets */
120 struct garmin_packet {
121 	struct list_head  list;
122 	int               seq;
123 	int               size; // the real size of the data array, always > 0
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 	spinlock_t lock;
145 	struct list_head pktlist;
146 };
147 
148 
149 #define STATE_NEW            0
150 #define STATE_INITIAL_DELAY  1
151 #define STATE_TIMEOUT        2
152 #define STATE_SESSION_REQ1   3
153 #define STATE_SESSION_REQ2   4
154 #define STATE_ACTIVE         5
155 
156 #define STATE_RESET	     8
157 #define STATE_DISCONNECTED   9
158 #define STATE_WAIT_TTY_ACK  10
159 #define STATE_GSP_WAIT_DATA 11
160 
161 #define MODE_NATIVE          0
162 #define MODE_GARMIN_SERIAL   1
163 
164 // Flags used in garmin_data.flags:
165 #define FLAGS_SESSION_REPLY_MASK  0x00C0
166 #define FLAGS_SESSION_REPLY1_SEEN 0x0080
167 #define FLAGS_SESSION_REPLY2_SEEN 0x0040
168 #define FLAGS_BULK_IN_ACTIVE      0x0020
169 #define FLAGS_THROTTLED           0x0010
170 #define CLEAR_HALT_REQUIRED       0x0001
171 
172 #define FLAGS_QUEUING             0x0100
173 #define FLAGS_APP_RESP_SEEN       0x0200
174 #define FLAGS_APP_REQ_SEEN        0x0400
175 #define FLAGS_DROP_DATA           0x0800
176 
177 #define FLAGS_GSP_SKIP            0x1000
178 #define FLAGS_GSP_DLESEEN         0x2000
179 
180 
181 
182 
183 
184 
185 /* function prototypes */
186 static void gsp_next_packet(struct garmin_data * garmin_data_p);
187 static int  garmin_write_bulk(struct usb_serial_port *port,
188 			     const unsigned char *buf, int count);
189 
190 /* some special packets to be send or received */
191 static unsigned char const GARMIN_START_SESSION_REQ[]
192 	= { 0, 0, 0, 0,  5, 0, 0, 0, 0, 0, 0, 0 };
193 static unsigned char const GARMIN_START_SESSION_REQ2[]
194 	= { 0, 0, 0, 0, 16, 0, 0, 0, 0, 0, 0, 0 };
195 static unsigned char const GARMIN_START_SESSION_REPLY[]
196 	= { 0, 0, 0, 0,  6, 0, 0, 0, 4, 0, 0, 0 };
197 static unsigned char const GARMIN_SESSION_ACTIVE_REPLY[]
198 	= { 0, 0, 0, 0, 17, 0, 0, 0, 4, 0, 0, 0, 0, 16, 0, 0 };
199 static unsigned char const GARMIN_BULK_IN_AVAIL_REPLY[]
200 	= { 0, 0, 0, 0,  2, 0, 0, 0, 0, 0, 0, 0 };
201 static unsigned char const GARMIN_APP_LAYER_REPLY[]
202 	= { 0x14, 0, 0, 0 };
203 static unsigned char const GARMIN_START_PVT_REQ[]
204 	= { 20, 0, 0, 0,  10, 0, 0, 0, 2, 0, 0, 0, 49, 0 };
205 static unsigned char const GARMIN_STOP_PVT_REQ[]
206 	= { 20, 0, 0, 0,  10, 0, 0, 0, 2, 0, 0, 0, 50, 0 };
207 static unsigned char const GARMIN_STOP_TRANSFER_REQ[]
208 	= { 20, 0, 0, 0,  10, 0, 0, 0, 2, 0, 0, 0, 0, 0 };
209 static unsigned char const GARMIN_STOP_TRANSFER_REQ_V2[]
210 	= { 20, 0, 0, 0,  10, 0, 0, 0, 1, 0, 0, 0, 0 };
211 static unsigned char const PRIVATE_REQ[]
212 	=    { 0x4B, 0x6E, 0x10, 0x01,  0xFF, 0, 0, 0, 0xFF, 0, 0, 0 };
213 
214 
215 
216 static struct usb_device_id id_table [] = {
217 	/* the same device id seems to be used by all usb enabled gps devices */
218 	{ USB_DEVICE(GARMIN_VENDOR_ID, 3 ) },
219 	{ }					/* Terminating entry */
220 };
221 
222 MODULE_DEVICE_TABLE (usb, id_table);
223 
224 static struct usb_driver garmin_driver = {
225 	.owner =	THIS_MODULE,
226 	.name =		"garmin_gps",
227 	.probe =	usb_serial_probe,
228 	.disconnect =	usb_serial_disconnect,
229 	.id_table =	id_table,
230 };
231 
232 
233 static inline int noResponseFromAppLayer(struct garmin_data * garmin_data_p)
234 {
235 	return ((garmin_data_p->flags
236 				& (FLAGS_APP_REQ_SEEN|FLAGS_APP_RESP_SEEN))
237 	        == FLAGS_APP_REQ_SEEN);
238 }
239 
240 
241 static inline int getLayerId(const __u8 *usbPacket)
242 {
243 	return __le32_to_cpup((__le32 *)(usbPacket));
244 }
245 
246 static inline int getPacketId(const __u8 *usbPacket)
247 {
248 	return __le32_to_cpup((__le32 *)(usbPacket+4));
249 }
250 
251 static inline int getDataLength(const __u8 *usbPacket)
252 {
253 	return __le32_to_cpup((__le32 *)(usbPacket+8));
254 }
255 
256 
257 /*
258  * check if the usb-packet in buf contains an abort-transfer command.
259  * (if yes, all queued data will be dropped)
260  */
261 static inline int isAbortTrfCmnd(const unsigned char *buf)
262 {
263 	if (0 == memcmp(buf, GARMIN_STOP_TRANSFER_REQ,
264 	                sizeof(GARMIN_STOP_TRANSFER_REQ)) ||
265 	    0 == memcmp(buf, GARMIN_STOP_TRANSFER_REQ_V2,
266 	                sizeof(GARMIN_STOP_TRANSFER_REQ_V2)))
267 		return 1;
268 	else
269 		return 0;
270 }
271 
272 
273 
274 static void send_to_tty(struct usb_serial_port *port,
275                         char *data, unsigned int actual_length)
276 {
277 	struct tty_struct *tty = port->tty;
278 	int i;
279 
280 	if (tty && actual_length) {
281 
282 		usb_serial_debug_data(debug, &port->dev,
283 					__FUNCTION__, actual_length, data);
284 
285 		for (i = 0; i < actual_length ; ++i) {
286 			/* if we insert more than TTY_FLIPBUF_SIZE characters,
287 			   we drop them. */
288 			if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
289 				tty_flip_buffer_push(tty);
290 			}
291 			/* this doesn't actually push the data through unless
292 			   tty->low_latency is set */
293 			tty_insert_flip_char(tty, data[i], 0);
294 		}
295 		tty_flip_buffer_push(tty);
296 	}
297 }
298 
299 
300 /******************************************************************************
301  * packet queue handling
302  ******************************************************************************/
303 
304 /*
305  * queue a received (usb-)packet for later processing
306  */
307 static int pkt_add(struct garmin_data * garmin_data_p,
308                    unsigned char *data, unsigned int data_length)
309 {
310 	int result = 0;
311 	unsigned long flags;
312 	struct garmin_packet *pkt;
313 
314 	/* process only packets containg data ... */
315 	if (data_length) {
316 		garmin_data_p->flags |= FLAGS_QUEUING;
317 		pkt = kmalloc(sizeof(struct garmin_packet)+data_length,
318 		              GFP_ATOMIC);
319 		if (pkt == NULL) {
320 			dev_err(&garmin_data_p->port->dev, "out of memory\n");
321 			return 0;
322 		}
323 		pkt->size = data_length;
324 		memcpy(pkt->data, data, data_length);
325 
326 		spin_lock_irqsave(&garmin_data_p->lock, flags);
327 		result = list_empty(&garmin_data_p->pktlist);
328 		pkt->seq = garmin_data_p->seq_counter++;
329 		list_add_tail(&pkt->list, &garmin_data_p->pktlist);
330 		spin_unlock_irqrestore(&garmin_data_p->lock, flags);
331 
332 		/* in serial mode, if someone is waiting for data from
333 		   the device, iconvert and send the next packet to tty. */
334 		if (result && (garmin_data_p->state == STATE_GSP_WAIT_DATA)) {
335 			gsp_next_packet(garmin_data_p);
336 		}
337 	}
338 	return result;
339 }
340 
341 
342 /* get the next pending packet */
343 static struct garmin_packet *pkt_pop(struct garmin_data * garmin_data_p)
344 {
345 	unsigned long flags;
346 	struct garmin_packet *result = NULL;
347 
348 	spin_lock_irqsave(&garmin_data_p->lock, flags);
349 	if (!list_empty(&garmin_data_p->pktlist)) {
350 		result = (struct garmin_packet *)garmin_data_p->pktlist.next;
351 		list_del(&result->list);
352 	}
353 	spin_unlock_irqrestore(&garmin_data_p->lock, flags);
354 	return result;
355 }
356 
357 
358 /* free up all queued data */
359 static void pkt_clear(struct garmin_data * garmin_data_p)
360 {
361 	unsigned long flags;
362 	struct garmin_packet *result = NULL;
363 
364 	dbg("%s", __FUNCTION__);
365 
366 	spin_lock_irqsave(&garmin_data_p->lock, flags);
367 	while (!list_empty(&garmin_data_p->pktlist)) {
368 		result = (struct garmin_packet *)garmin_data_p->pktlist.next;
369 		list_del(&result->list);
370 		kfree(result);
371 	}
372 	spin_unlock_irqrestore(&garmin_data_p->lock, flags);
373 }
374 
375 
376 /******************************************************************************
377  * garmin serial protocol handling handling
378  ******************************************************************************/
379 
380 /* send an ack packet back to the tty */
381 static int gsp_send_ack(struct garmin_data * garmin_data_p, __u8 pkt_id)
382 {
383 	__u8 pkt[10];
384         __u8 cksum = 0;
385         __u8 *ptr = pkt;
386         unsigned  l = 0;
387 
388 	dbg("%s - pkt-id: 0x%X.", __FUNCTION__, 0xFF & pkt_id);
389 
390 	*ptr++ = DLE;
391 	*ptr++ = ACK;
392 	cksum += ACK;
393 
394 	*ptr++ = 2;
395 	cksum += 2;
396 
397 	*ptr++ = pkt_id;
398 	cksum += pkt_id;
399 
400 	if (pkt_id == DLE) {
401 		*ptr++ = DLE;
402 	}
403 
404 	*ptr++ = 0;
405 	*ptr++ = 0xFF & (-cksum);
406 	*ptr++ = DLE;
407 	*ptr++ = ETX;
408 
409 	l = ptr-pkt;
410 
411 	send_to_tty(garmin_data_p->port, pkt, l);
412 	return 0;
413 }
414 
415 
416 
417 /*
418  * called for a complete packet received from tty layer
419  *
420  * the complete packet (pkzid ... cksum) is in garmin_data_p->inbuf starting
421  * at GSP_INITIAL_OFFSET.
422  *
423  * count - number of bytes in the input buffer including space reserved for
424  *         the usb header: GSP_INITIAL_OFFSET + number of bytes in packet
425  *         (including pkt-id, data-length a. cksum)
426  */
427 static int gsp_rec_packet(struct garmin_data * garmin_data_p, int count)
428 {
429 	const __u8* recpkt = garmin_data_p->inbuffer+GSP_INITIAL_OFFSET;
430         __le32 *usbdata = (__le32 *) garmin_data_p->inbuffer;
431 
432 	int cksum = 0;
433 	int n = 0;
434 	int pktid = recpkt[0];
435 	int size = recpkt[1];
436 
437 	usb_serial_debug_data(debug, &garmin_data_p->port->dev,
438 			       __FUNCTION__, count-GSP_INITIAL_OFFSET, recpkt);
439 
440 	if (size != (count-GSP_INITIAL_OFFSET-3)) {
441 		dbg("%s - invalid size, expected %d bytes, got %d",
442 			__FUNCTION__, size, (count-GSP_INITIAL_OFFSET-3));
443 		return -EINVPKT;
444 	}
445 
446 	cksum += *recpkt++;
447 	cksum += *recpkt++;
448 
449 	// sanity check, remove after test ...
450 	if ((__u8*)&(usbdata[3]) != recpkt) {
451 		dbg("%s - ptr mismatch %p - %p",
452 			__FUNCTION__, &(usbdata[4]), recpkt);
453 		return -EINVPKT;
454 	}
455 
456 	while (n < size) {
457 		cksum += *recpkt++;
458 		n++;
459 	}
460 
461        if ((0xff & (cksum + *recpkt)) != 0) {
462                 dbg("%s - invalid checksum, expected %02x, got %02x",
463                         __FUNCTION__, 0xff & -cksum, 0xff & *recpkt);
464                 return -EINVPKT;
465         }
466 
467 	usbdata[0] = __cpu_to_le32(GARMIN_LAYERID_APPL);
468 	usbdata[1] = __cpu_to_le32(pktid);
469 	usbdata[2] = __cpu_to_le32(size);
470 
471 	garmin_write_bulk (garmin_data_p->port, garmin_data_p->inbuffer,
472 			   GARMIN_PKTHDR_LENGTH+size);
473 
474 	/* if this was an abort-transfer command, flush all
475 	   queued data. */
476 	if (isAbortTrfCmnd(garmin_data_p->inbuffer)) {
477 		garmin_data_p->flags |= FLAGS_DROP_DATA;
478 		pkt_clear(garmin_data_p);
479 	}
480 
481 	return count;
482 }
483 
484 
485 
486 /*
487  * Called for data received from tty
488  *
489  * buf contains the data read, it may span more than one packet or even
490  * incomplete packets
491  *
492  * input record should be a serial-record, but it may not be complete.
493  * Copy it into our local buffer, until an etx is seen (or an error
494  * occurs).
495  * Once the record is complete, convert into a usb packet and send it
496  * to the bulk pipe, send an ack back to the tty.
497  *
498  * If the input is an ack, just send the last queued packet to the
499  * tty layer.
500  *
501  * if the input is an abort command, drop all queued data.
502  */
503 
504 static int gsp_receive(struct garmin_data * garmin_data_p,
505                        const unsigned char *buf, int count)
506 {
507 	int offs = 0;
508 	int ack_or_nak_seen = 0;
509 	int i = 0;
510 	__u8 *dest = garmin_data_p->inbuffer;
511 	int size = garmin_data_p->insize;
512 	// dleSeen: set if last byte read was a DLE
513 	int dleSeen = garmin_data_p->flags & FLAGS_GSP_DLESEEN;
514 	// skip: if set, skip incoming data until possible start of
515 	//       new packet
516 	int skip = garmin_data_p->flags & FLAGS_GSP_SKIP;
517 	__u8 data;
518 
519 	dbg("%s - dle=%d skip=%d size=%d count=%d",
520 		__FUNCTION__, dleSeen, skip, size, count);
521 
522 	if (size == 0) {
523 		size = GSP_INITIAL_OFFSET;
524 	}
525 
526 	while (offs < count) {
527 
528 		data = *(buf+offs);
529 		offs ++;
530 
531 		if (data == DLE) {
532 			if (skip) { /* start of a new pkt */
533 				skip = 0;
534 				size = GSP_INITIAL_OFFSET;
535 				dleSeen = 1;
536 			} else if (dleSeen) {
537 				dest[size++] = data;
538 				dleSeen = 0;
539 			} else {
540 				dleSeen = 1;
541 			}
542 		} else if (data == ETX) {
543 			if (dleSeen) {
544 				/* packet complete */
545 
546 				data = dest[GSP_INITIAL_OFFSET];
547 
548 				if (data == ACK) {
549 					ack_or_nak_seen = ACK;
550 					dbg("ACK packet complete.");
551 				} else if (data == NAK) {
552 					ack_or_nak_seen = NAK;
553 					dbg("NAK packet complete.");
554 				} else {
555 					dbg("packet complete "
556 						        "- 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.", __FUNCTION__);
580 			skip = 1;
581 			size = GSP_INITIAL_OFFSET;
582 			dleSeen = 0;
583 		}
584 	}
585 
586 	garmin_data_p->insize = size;
587 
588 	// copy flags back to structure
589 	if (skip)
590 		garmin_data_p->flags |= FLAGS_GSP_SKIP;
591 	else
592 		garmin_data_p->flags &= ~FLAGS_GSP_SKIP;
593 
594 	if (dleSeen)
595 		garmin_data_p->flags |= FLAGS_GSP_DLESEEN;
596 	else
597 		garmin_data_p->flags &= ~FLAGS_GSP_DLESEEN;
598 
599 	if (ack_or_nak_seen) {
600 		garmin_data_p->state = STATE_GSP_WAIT_DATA;
601 		gsp_next_packet(garmin_data_p);
602 	}
603 
604 	return count;
605 }
606 
607 
608 
609 
610 /*
611  * Sends a usb packet to the tty
612  *
613  * Assumes, that all packages and at an usb-packet boundary.
614  *
615  * return <0 on error, 0 if packet is incomplete or > 0 if packet was sent
616  */
617 static int gsp_send(struct garmin_data * garmin_data_p,
618 		    const unsigned char *buf, int count)
619 {
620 	const unsigned char *src;
621 	unsigned char *dst;
622 	int pktid = 0;
623 	int datalen = 0;
624 	int cksum = 0;
625 	int i=0;
626 	int k;
627 
628 	dbg("%s - state %d - %d bytes.", __FUNCTION__,
629 	         garmin_data_p->state, count);
630 
631 	k = garmin_data_p->outsize;
632 	if ((k+count) > GPS_OUT_BUFSIZ) {
633 		dbg("packet too large");
634 		garmin_data_p->outsize = 0;
635 		return -4;
636 	}
637 
638 	memcpy(garmin_data_p->outbuffer+k, buf, count);
639 	k += count;
640 	garmin_data_p->outsize = k;
641 
642 	if (k >= GARMIN_PKTHDR_LENGTH) {
643 		pktid  = getPacketId(garmin_data_p->outbuffer);
644 		datalen= getDataLength(garmin_data_p->outbuffer);
645 		i = GARMIN_PKTHDR_LENGTH + datalen;
646 		if (k < i)
647 			return 0;
648 	} else {
649 		return 0;
650 	}
651 
652 	dbg("%s - %d bytes in buffer, %d bytes in pkt.", __FUNCTION__,
653 	         k, i);
654 
655 	/* garmin_data_p->outbuffer now contains a complete packet */
656 
657 	usb_serial_debug_data(debug, &garmin_data_p->port->dev,
658 		                   __FUNCTION__, k, garmin_data_p->outbuffer);
659 
660 	garmin_data_p->outsize = 0;
661 
662 	if (GARMIN_LAYERID_APPL != getLayerId(garmin_data_p->outbuffer)) {
663 		dbg("not an application packet (%d)",
664 		        getLayerId(garmin_data_p->outbuffer));
665 		return -1;
666 	}
667 
668 	if (pktid > 255) {
669 		dbg("packet-id %d too large", pktid);
670 		return -2;
671 	}
672 
673 	if (datalen > 255) {
674 		dbg("packet-size %d too large", datalen);
675 		return -3;
676 	}
677 
678 	/* the serial protocol should be able to handle this packet */
679 
680 	k = 0;
681 	src = garmin_data_p->outbuffer+GARMIN_PKTHDR_LENGTH;
682 	for (i=0; i<datalen; i++) {
683 		if (*src++ == DLE)
684 			k++;
685 	}
686 
687 	src = garmin_data_p->outbuffer+GARMIN_PKTHDR_LENGTH;
688 	if (k > (GARMIN_PKTHDR_LENGTH-2)) {
689 		/* can't add stuffing DLEs in place, move data to end
690                    of buffer ... */
691 		dst = garmin_data_p->outbuffer+GPS_OUT_BUFSIZ-datalen;
692 		memcpy(dst, src, datalen);
693 		src = dst;
694 	}
695 
696 	dst = garmin_data_p->outbuffer;
697 
698 	*dst++ = DLE;
699 	*dst++ = pktid;
700 	cksum += pktid;
701 	*dst++ = datalen;
702 	cksum += datalen;
703 	if (datalen == DLE)
704 		*dst++ = DLE;
705 
706 	for (i=0; i<datalen; i++) {
707 		__u8 c = *src++;
708 		*dst++ = c;
709 		cksum += c;
710 		if (c == DLE)
711 			*dst++ = DLE;
712 	}
713 
714 	cksum = 0xFF & -cksum;
715 	*dst++ = cksum;
716 	if (cksum == DLE)
717 		*dst++ = DLE;
718 	*dst++ = DLE;
719 	*dst++ = ETX;
720 
721 	i = dst-garmin_data_p->outbuffer;
722 
723 	send_to_tty(garmin_data_p->port, garmin_data_p->outbuffer, i);
724 
725 	garmin_data_p->pkt_id = pktid;
726 	garmin_data_p->state  = STATE_WAIT_TTY_ACK;
727 
728 	return i;
729 }
730 
731 
732 
733 
734 
735 /*
736  * Process the next pending data packet - if there is one
737  */
738 static void gsp_next_packet(struct garmin_data * garmin_data_p)
739 {
740 	struct garmin_packet *pkt = NULL;
741 
742 	while ((pkt = pkt_pop(garmin_data_p)) != NULL) {
743 		dbg("%s - next pkt: %d", __FUNCTION__, pkt->seq);
744 		if (gsp_send(garmin_data_p, pkt->data, pkt->size) > 0) {
745 			kfree(pkt);
746 			return;
747 		}
748 		kfree(pkt);
749 	}
750 }
751 
752 
753 
754 
755 /******************************************************************************
756  * garmin native mode
757  ******************************************************************************/
758 
759 
760 /*
761  * Called for data received from tty
762  *
763  * The input data is expected to be in garmin usb-packet format.
764  *
765  * buf contains the data read, it may span more than one packet
766  * or even incomplete packets
767  */
768 static int nat_receive(struct garmin_data * garmin_data_p,
769                        const unsigned char *buf, int count)
770 {
771 	__u8 * dest;
772 	int offs = 0;
773 	int result = count;
774 	int len;
775 
776 	while (offs < count) {
777 		// if buffer contains header, copy rest of data
778 		if (garmin_data_p->insize >= GARMIN_PKTHDR_LENGTH)
779 			len = GARMIN_PKTHDR_LENGTH
780 			      +getDataLength(garmin_data_p->inbuffer);
781 		else
782 			len = GARMIN_PKTHDR_LENGTH;
783 
784 		if (len >= GPS_IN_BUFSIZ) {
785 			/* seem to be an invalid packet, ignore rest of input */
786 			dbg("%s - packet size too large: %d",
787 			        __FUNCTION__, len);
788 			garmin_data_p->insize = 0;
789 			count = 0;
790 			result = -EINVPKT;
791 		} else {
792 			len -= garmin_data_p->insize;
793 			if (len > (count-offs))
794 				len = (count-offs);
795 			if (len > 0) {
796 				dest = garmin_data_p->inbuffer
797 				       	+garmin_data_p->insize;
798 				memcpy(dest, buf+offs, len);
799 				garmin_data_p->insize += len;
800 				offs += len;
801 			}
802 		}
803 
804 		/* do we have a complete packet ? */
805 		if (garmin_data_p->insize >= GARMIN_PKTHDR_LENGTH) {
806 			len = GARMIN_PKTHDR_LENGTH+
807 			   getDataLength(garmin_data_p->inbuffer);
808 			if (garmin_data_p->insize >= len) {
809 				garmin_write_bulk (garmin_data_p->port,
810 				                   garmin_data_p->inbuffer,
811 				                   len);
812 				garmin_data_p->insize = 0;
813 
814 				/* if this was an abort-transfer command,
815 				   flush all queued data. */
816 				if (isAbortTrfCmnd(garmin_data_p->inbuffer)) {
817 					garmin_data_p->flags |= FLAGS_DROP_DATA;
818 					pkt_clear(garmin_data_p);
819 				}
820 			}
821 		}
822 	}
823 	return result;
824 }
825 
826 
827 /******************************************************************************
828  * private packets
829  ******************************************************************************/
830 
831 static void priv_status_resp(struct usb_serial_port *port)
832 {
833 	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
834 	__le32 *pkt = (__le32 *)garmin_data_p->privpkt;
835 
836 	pkt[0] = __cpu_to_le32(GARMIN_LAYERID_PRIVATE);
837 	pkt[1] = __cpu_to_le32(PRIV_PKTID_INFO_RESP);
838 	pkt[2] = __cpu_to_le32(12);
839 	pkt[3] = __cpu_to_le32(VERSION_MAJOR << 16 | VERSION_MINOR);
840 	pkt[4] = __cpu_to_le32(garmin_data_p->mode);
841 	pkt[5] = __cpu_to_le32(garmin_data_p->serial_num);
842 
843 	send_to_tty(port, (__u8*)pkt, 6*4);
844 }
845 
846 
847 /******************************************************************************
848  * Garmin specific driver functions
849  ******************************************************************************/
850 
851 static int process_resetdev_request(struct usb_serial_port *port)
852 {
853 	int status;
854 	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
855 
856 	garmin_data_p->flags &= ~(CLEAR_HALT_REQUIRED);
857 	garmin_data_p->state = STATE_RESET;
858 	garmin_data_p->serial_num = 0;
859 
860 	usb_kill_urb (port->interrupt_in_urb);
861 	dbg("%s - usb_reset_device", __FUNCTION__ );
862 	status = usb_reset_device(port->serial->dev);
863 	if (status)
864 		dbg("%s - usb_reset_device failed: %d",
865 			__FUNCTION__, status);
866 	return status;
867 }
868 
869 
870 
871 /*
872  * clear all cached data
873  */
874 static int garmin_clear(struct garmin_data * garmin_data_p)
875 {
876 	int status = 0;
877 
878 	struct usb_serial_port *port = garmin_data_p->port;
879 
880 	if (port != NULL && garmin_data_p->flags & FLAGS_APP_RESP_SEEN) {
881 		/* send a terminate command */
882 		status = garmin_write_bulk(port, GARMIN_STOP_TRANSFER_REQ,
883 		                           sizeof(GARMIN_STOP_TRANSFER_REQ));
884 	}
885 
886 	/* flush all queued data */
887 	pkt_clear(garmin_data_p);
888 
889 	garmin_data_p->insize = 0;
890 	garmin_data_p->outsize = 0;
891 
892 	return status;
893 }
894 
895 
896 
897 
898 
899 
900 static int garmin_init_session(struct usb_serial_port *port)
901 {
902 	struct usb_serial *serial = port->serial;
903 	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
904 	int status = 0;
905 
906 	if (status == 0) {
907 		usb_kill_urb (port->interrupt_in_urb);
908 
909 		dbg("%s - adding interrupt input", __FUNCTION__);
910 		port->interrupt_in_urb->dev = serial->dev;
911 		status = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
912 		if (status)
913 			dev_err(&serial->dev->dev,
914 			        "%s - failed submitting interrupt urb,"
915 				" error %d\n",
916 			        __FUNCTION__, status);
917 	}
918 
919 	if (status == 0) {
920 		dbg("%s - starting session ...", __FUNCTION__);
921 		garmin_data_p->state = STATE_ACTIVE;
922 		status = garmin_write_bulk(port, GARMIN_START_SESSION_REQ,
923 		                           sizeof(GARMIN_START_SESSION_REQ));
924 
925 		if (status >= 0) {
926 
927 			garmin_data_p->ignorePkts++;
928 
929 			/* not needed, but the win32 driver does it too ... */
930 			status = garmin_write_bulk(port,
931 						   GARMIN_START_SESSION_REQ2,
932 			                           sizeof(GARMIN_START_SESSION_REQ2));
933 			if (status >= 0) {
934 				status = 0;
935 				garmin_data_p->ignorePkts++;
936 			}
937 		}
938 	}
939 
940 	return status;
941 }
942 
943 
944 
945 
946 
947 static int garmin_open (struct usb_serial_port *port, struct file *filp)
948 {
949 	int status = 0;
950 	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
951 
952 	dbg("%s - port %d", __FUNCTION__, port->number);
953 
954 	/*
955 	 * Force low_latency on so that our tty_push actually forces the data
956 	 * through, otherwise it is scheduled, and with high data rates (like
957 	 * with OHCI) data can get lost.
958 	 */
959 	if (port->tty)
960 		port->tty->low_latency = 1;
961 
962 	garmin_data_p->mode  = initial_mode;
963 	garmin_data_p->count = 0;
964 	garmin_data_p->flags = 0;
965 
966 	/* shutdown any bulk reads that might be going on */
967 	usb_kill_urb (port->write_urb);
968 	usb_kill_urb (port->read_urb);
969 
970 	if (garmin_data_p->state == STATE_RESET) {
971 		status = garmin_init_session(port);
972 	}
973 
974 	garmin_data_p->state = STATE_ACTIVE;
975 
976 	return status;
977 }
978 
979 
980 static void garmin_close (struct usb_serial_port *port, struct file * filp)
981 {
982 	struct usb_serial *serial = port->serial;
983 	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
984 
985 	dbg("%s - port %d - mode=%d state=%d flags=0x%X", __FUNCTION__,
986 		port->number, garmin_data_p->mode,
987 		garmin_data_p->state, garmin_data_p->flags);
988 
989 	if (!serial)
990 		return;
991 
992 	garmin_clear(garmin_data_p);
993 
994 	/* shutdown our urbs */
995 	usb_kill_urb (port->read_urb);
996 	usb_kill_urb (port->write_urb);
997 
998 	if (noResponseFromAppLayer(garmin_data_p) ||
999 	    ((garmin_data_p->flags & CLEAR_HALT_REQUIRED) != 0)) {
1000 		process_resetdev_request(port);
1001 		garmin_data_p->state = STATE_RESET;
1002 	} else {
1003 		garmin_data_p->state = STATE_DISCONNECTED;
1004 	}
1005 }
1006 
1007 
1008 static void garmin_write_bulk_callback (struct urb *urb, struct pt_regs *regs)
1009 {
1010 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
1011 	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
1012 
1013 	/* free up the transfer buffer, as usb_free_urb() does not do this */
1014 	kfree (urb->transfer_buffer);
1015 
1016 	dbg("%s - port %d", __FUNCTION__, port->number);
1017 
1018 	if (urb->status) {
1019 		dbg("%s - nonzero write bulk status received: %d",
1020 			__FUNCTION__, urb->status);
1021 		garmin_data_p->flags |= CLEAR_HALT_REQUIRED;
1022 	}
1023 
1024 	schedule_work(&port->work);
1025 }
1026 
1027 
1028 static int garmin_write_bulk (struct usb_serial_port *port,
1029                               const unsigned char *buf, int count)
1030 {
1031 	struct usb_serial *serial = port->serial;
1032 	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
1033 	struct urb *urb;
1034 	unsigned char *buffer;
1035 	int status;
1036 
1037 	dbg("%s - port %d, state %d", __FUNCTION__, port->number,
1038 		garmin_data_p->state);
1039 
1040 	garmin_data_p->flags &= ~FLAGS_DROP_DATA;
1041 
1042 	buffer = kmalloc (count, GFP_ATOMIC);
1043 	if (!buffer) {
1044 		dev_err(&port->dev, "out of memory\n");
1045 		return -ENOMEM;
1046 	}
1047 
1048 	urb = usb_alloc_urb(0, GFP_ATOMIC);
1049 	if (!urb) {
1050 		dev_err(&port->dev, "no more free urbs\n");
1051 		kfree (buffer);
1052 		return -ENOMEM;
1053 	}
1054 
1055 	memcpy (buffer, buf, count);
1056 
1057 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, buffer);
1058 
1059 	usb_fill_bulk_urb (urb, serial->dev,
1060 			 	usb_sndbulkpipe (serial->dev,
1061 				port->bulk_out_endpointAddress),
1062 				buffer, count,
1063 				garmin_write_bulk_callback, port);
1064 	urb->transfer_flags |= URB_ZERO_PACKET;
1065 
1066 	if (GARMIN_LAYERID_APPL == getLayerId(buffer)) {
1067 		garmin_data_p->flags |= FLAGS_APP_REQ_SEEN;
1068 		if (garmin_data_p->mode == MODE_GARMIN_SERIAL)  {
1069 			pkt_clear(garmin_data_p);
1070 			garmin_data_p->state = STATE_GSP_WAIT_DATA;
1071 		}
1072 	}
1073 
1074 	/* send it down the pipe */
1075 	status = usb_submit_urb(urb, GFP_ATOMIC);
1076 	if (status) {
1077 		dev_err(&port->dev,
1078 		        "%s - usb_submit_urb(write bulk) "
1079 		        "failed with status = %d\n",
1080 				__FUNCTION__, status);
1081 		count = status;
1082 	} else {
1083 
1084 		if (GARMIN_LAYERID_APPL == getLayerId(buffer)
1085 		    && (garmin_data_p->mode == MODE_GARMIN_SERIAL))  {
1086 
1087 			gsp_send_ack(garmin_data_p, buffer[4]);
1088 		}
1089 	}
1090 
1091 	/* we are done with this urb, so let the host driver
1092 	 * really free it when it is finished with it */
1093 	usb_free_urb (urb);
1094 
1095 	return count;
1096 }
1097 
1098 
1099 
1100 static int garmin_write (struct usb_serial_port *port,
1101                          const unsigned char *buf, int count)
1102 {
1103 	int pktid, pktsiz, len;
1104 	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
1105 	__le32 *privpkt = (__le32 *)garmin_data_p->privpkt;
1106 
1107 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, buf);
1108 
1109 	/* check for our private packets */
1110 	if (count >= GARMIN_PKTHDR_LENGTH) {
1111 
1112 		len = PRIVPKTSIZ;
1113 		if (count < len)
1114 			len = count;
1115 
1116 		memcpy(garmin_data_p->privpkt, buf, len);
1117 
1118 		pktsiz = getDataLength(garmin_data_p->privpkt);
1119 		pktid  = getPacketId(garmin_data_p->privpkt);
1120 
1121 		if (count == (GARMIN_PKTHDR_LENGTH+pktsiz)
1122 		    && GARMIN_LAYERID_PRIVATE == getLayerId(garmin_data_p->privpkt)) {
1123 
1124 			dbg("%s - processing private request %d",
1125 				__FUNCTION__, pktid);
1126 
1127 			// drop all unfinished transfers
1128 			garmin_clear(garmin_data_p);
1129 
1130 			switch(pktid) {
1131 
1132 			case PRIV_PKTID_SET_DEBUG:
1133 				if (pktsiz != 4)
1134 					return -EINVPKT;
1135 				debug = __le32_to_cpu(privpkt[3]);
1136 				dbg("%s - debug level set to 0x%X",
1137 					__FUNCTION__, debug);
1138 				break;
1139 
1140 			case PRIV_PKTID_SET_MODE:
1141 				if (pktsiz != 4)
1142 					return -EINVPKT;
1143 				garmin_data_p->mode = __le32_to_cpu(privpkt[3]);
1144 				dbg("%s - mode set to %d",
1145 					__FUNCTION__, garmin_data_p->mode);
1146 				break;
1147 
1148 			case PRIV_PKTID_INFO_REQ:
1149 				priv_status_resp(port);
1150 				break;
1151 
1152 			case PRIV_PKTID_RESET_REQ:
1153 				garmin_data_p->flags |= FLAGS_APP_REQ_SEEN;
1154 				break;
1155 
1156 			case PRIV_PKTID_SET_DEF_MODE:
1157 				if (pktsiz != 4)
1158 					return -EINVPKT;
1159 				initial_mode = __le32_to_cpu(privpkt[3]);
1160 				dbg("%s - initial_mode set to %d",
1161 					__FUNCTION__,
1162 					garmin_data_p->mode);
1163 				break;
1164 			}
1165 			return count;
1166 		}
1167 	}
1168 
1169 	if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
1170 		return gsp_receive(garmin_data_p, buf, count);
1171 	} else {	/* MODE_NATIVE */
1172 		return nat_receive(garmin_data_p, buf, count);
1173 	}
1174 }
1175 
1176 
1177 static int garmin_write_room (struct usb_serial_port *port)
1178 {
1179 	/*
1180 	 * Report back the bytes currently available in the output buffer.
1181 	 */
1182 	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
1183 	return GPS_OUT_BUFSIZ-garmin_data_p->outsize;
1184 }
1185 
1186 
1187 static int garmin_chars_in_buffer (struct usb_serial_port *port)
1188 {
1189 	/*
1190 	 * Report back the number of bytes currently in our input buffer.
1191          * Will this lock up the driver - the buffer contains an incomplete
1192          * package which will not be written to the device until it
1193          * has been completed ?
1194          */
1195 	//struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
1196 	//return garmin_data_p->insize;
1197 	return 0;
1198 }
1199 
1200 
1201 static void garmin_read_process(struct garmin_data * garmin_data_p,
1202 				 unsigned char *data, unsigned data_length)
1203 {
1204 	if (garmin_data_p->flags & FLAGS_DROP_DATA) {
1205 		/* abort-transfer cmd is actice */
1206 		dbg("%s - pkt dropped", __FUNCTION__);
1207 	} else if (garmin_data_p->state != STATE_DISCONNECTED &&
1208 	           garmin_data_p->state != STATE_RESET ) {
1209 
1210 		/* remember any appl.layer packets, so we know
1211 		   if a reset is required or not when closing
1212 		   the device */
1213 		if (0 == memcmp(data, GARMIN_APP_LAYER_REPLY,
1214 		                sizeof(GARMIN_APP_LAYER_REPLY)))
1215 			garmin_data_p->flags |= FLAGS_APP_RESP_SEEN;
1216 
1217 		/* if throttling is active or postprecessing is required
1218 		   put the received data in th input queue, otherwise
1219 		   send it directly to the tty port */
1220 		if (garmin_data_p->flags & FLAGS_QUEUING) {
1221 			pkt_add(garmin_data_p, data, data_length);
1222 		} else if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
1223 			if (getLayerId(data) == GARMIN_LAYERID_APPL) {
1224 				pkt_add(garmin_data_p, data, data_length);
1225 			}
1226 		} else {
1227 			send_to_tty(garmin_data_p->port, data, data_length);
1228 		}
1229 	}
1230 }
1231 
1232 
1233 static void garmin_read_bulk_callback (struct urb *urb, struct pt_regs *regs)
1234 {
1235 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
1236 	struct usb_serial *serial =  port->serial;
1237 	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
1238 	unsigned char *data = urb->transfer_buffer;
1239 	int status;
1240 
1241 	dbg("%s - port %d", __FUNCTION__, port->number);
1242 
1243 	if (!serial) {
1244 		dbg("%s - bad serial pointer, exiting", __FUNCTION__);
1245 		return;
1246 	}
1247 
1248 	if (urb->status) {
1249 		dbg("%s - nonzero read bulk status received: %d",
1250 			__FUNCTION__, urb->status);
1251 		return;
1252 	}
1253 
1254 	usb_serial_debug_data(debug, &port->dev,
1255 				__FUNCTION__, urb->actual_length, data);
1256 
1257 	garmin_read_process(garmin_data_p, data, urb->actual_length);
1258 
1259 	/* Continue trying to read until nothing more is received  */
1260 	if (urb->actual_length > 0) {
1261 		usb_fill_bulk_urb (port->read_urb, serial->dev,
1262 			   usb_rcvbulkpipe (serial->dev,
1263 					    port->bulk_in_endpointAddress),
1264 			   port->read_urb->transfer_buffer,
1265 			   port->read_urb->transfer_buffer_length,
1266 			   garmin_read_bulk_callback, port);
1267 		status = usb_submit_urb(port->read_urb, GFP_ATOMIC);
1268 		if (status)
1269 			dev_err(&port->dev,
1270 				"%s - failed resubmitting read urb, error %d\n",
1271 			        __FUNCTION__, status);
1272 	}
1273 	return;
1274 }
1275 
1276 
1277 static void garmin_read_int_callback (struct urb *urb, struct pt_regs *regs)
1278 {
1279 	int status;
1280 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
1281 	struct usb_serial *serial = port->serial;
1282 	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
1283 	unsigned char *data = urb->transfer_buffer;
1284 
1285 	switch (urb->status) {
1286 	case 0:
1287 		/* success */
1288 		break;
1289 	case -ECONNRESET:
1290 	case -ENOENT:
1291 	case -ESHUTDOWN:
1292 		/* this urb is terminated, clean up */
1293 		dbg("%s - urb shutting down with status: %d",
1294 			__FUNCTION__, urb->status);
1295 		return;
1296 	default:
1297 		dbg("%s - nonzero urb status received: %d",
1298 			__FUNCTION__, urb->status);
1299 		return;
1300 	}
1301 
1302 	usb_serial_debug_data(debug, &port->dev, __FUNCTION__,
1303 				urb->actual_length, urb->transfer_buffer);
1304 
1305 	if (urb->actual_length == sizeof(GARMIN_BULK_IN_AVAIL_REPLY) &&
1306 	    0 == memcmp(data, GARMIN_BULK_IN_AVAIL_REPLY,
1307 		        sizeof(GARMIN_BULK_IN_AVAIL_REPLY))) {
1308 
1309 		dbg("%s - bulk data available.", __FUNCTION__);
1310 
1311 		/* bulk data available */
1312 		usb_fill_bulk_urb (port->read_urb, serial->dev,
1313 				usb_rcvbulkpipe (serial->dev,
1314 				port->bulk_in_endpointAddress),
1315 				port->read_urb->transfer_buffer,
1316 				port->read_urb->transfer_buffer_length,
1317 				garmin_read_bulk_callback, port);
1318 		status = usb_submit_urb(port->read_urb, GFP_KERNEL);
1319 		if (status) {
1320 			dev_err(&port->dev,
1321 				"%s - failed submitting read urb, error %d\n",
1322 			__FUNCTION__, status);
1323 		}
1324 
1325 	} else if (urb->actual_length == (4+sizeof(GARMIN_START_SESSION_REPLY))
1326 			 && 0 == memcmp(data, GARMIN_START_SESSION_REPLY,
1327 			                sizeof(GARMIN_START_SESSION_REPLY))) {
1328 
1329 		garmin_data_p->flags |= FLAGS_SESSION_REPLY1_SEEN;
1330 
1331 		/* save the serial number */
1332 		garmin_data_p->serial_num
1333 			= __le32_to_cpup((__le32*)(data+GARMIN_PKTHDR_LENGTH));
1334 
1335 		dbg("%s - start-of-session reply seen - serial %u.",
1336 			__FUNCTION__, garmin_data_p->serial_num);
1337 	}
1338 
1339 	if (garmin_data_p->ignorePkts) {
1340 		/* this reply belongs to a request generated by the driver,
1341 		   ignore it. */
1342 		dbg("%s - pkt ignored (%d)",
1343 			__FUNCTION__, garmin_data_p->ignorePkts);
1344 		garmin_data_p->ignorePkts--;
1345 	} else {
1346 		garmin_read_process(garmin_data_p, data, urb->actual_length);
1347 	}
1348 
1349 	port->interrupt_in_urb->dev = port->serial->dev;
1350 	status = usb_submit_urb (urb, GFP_ATOMIC);
1351 	if (status)
1352 		dev_err(&urb->dev->dev,
1353 			"%s - Error %d submitting interrupt urb\n",
1354 			__FUNCTION__, status);
1355 }
1356 
1357 
1358 /*
1359  * Sends the next queued packt to the tty port (garmin native mode only)
1360  * and then sets a timer to call itself again until all queued data
1361  * is sent.
1362  */
1363 static int garmin_flush_queue(struct garmin_data * garmin_data_p)
1364 {
1365 	struct garmin_packet *pkt;
1366 
1367 	if ((garmin_data_p->flags & FLAGS_THROTTLED) == 0) {
1368 		pkt = pkt_pop(garmin_data_p);
1369 		if (pkt != NULL) {
1370 
1371 			send_to_tty(garmin_data_p->port, pkt->data, pkt->size);
1372 			kfree(pkt);
1373 			mod_timer(&garmin_data_p->timer, (1)+jiffies);
1374 
1375 		} else {
1376 			garmin_data_p->flags &= ~FLAGS_QUEUING;
1377 		}
1378 	}
1379 	return 0;
1380 }
1381 
1382 
1383 static void garmin_throttle (struct usb_serial_port *port)
1384 {
1385 	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
1386 
1387 	dbg("%s - port %d", __FUNCTION__, port->number);
1388 	/* set flag, data received will be put into a queue
1389 	   for later processing */
1390 	garmin_data_p->flags |= FLAGS_QUEUING|FLAGS_THROTTLED;
1391 }
1392 
1393 
1394 static void garmin_unthrottle (struct usb_serial_port *port)
1395 {
1396 	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
1397 
1398 	dbg("%s - port %d", __FUNCTION__, port->number);
1399 	garmin_data_p->flags &= ~FLAGS_THROTTLED;
1400 
1401 	/* in native mode send queued data to tty, in
1402 	   serial mode nothing needs to be done here */
1403 	if (garmin_data_p->mode == MODE_NATIVE)
1404 		garmin_flush_queue(garmin_data_p);
1405 }
1406 
1407 
1408 
1409 /*
1410  * The timer is currently only used to send queued packets to
1411  * the tty in cases where the protocol provides no own handshaking
1412  * to initiate the transfer.
1413  */
1414 static void timeout_handler(unsigned long data)
1415 {
1416 	struct garmin_data *garmin_data_p = (struct garmin_data *) data;
1417 
1418 	/* send the next queued packet to the tty port */
1419 	if (garmin_data_p->mode == MODE_NATIVE)
1420 		if (garmin_data_p->flags & FLAGS_QUEUING)
1421 			garmin_flush_queue(garmin_data_p);
1422 }
1423 
1424 
1425 
1426 static int garmin_attach (struct usb_serial *serial)
1427 {
1428 	int status = 0;
1429 	struct usb_serial_port *port = serial->port[0];
1430 	struct garmin_data * garmin_data_p = NULL;
1431 
1432 	dbg("%s", __FUNCTION__);
1433 
1434 	garmin_data_p = kmalloc (sizeof(struct garmin_data), GFP_KERNEL);
1435 	if (garmin_data_p == NULL) {
1436 		dev_err(&port->dev, "%s - Out of memory\n", __FUNCTION__);
1437 		return -ENOMEM;
1438 	}
1439 	memset (garmin_data_p, 0, sizeof(struct garmin_data));
1440 	init_timer(&garmin_data_p->timer);
1441 	spin_lock_init(&garmin_data_p->lock);
1442 	INIT_LIST_HEAD(&garmin_data_p->pktlist);
1443 	//garmin_data_p->timer.expires = jiffies + session_timeout;
1444 	garmin_data_p->timer.data = (unsigned long)garmin_data_p;
1445 	garmin_data_p->timer.function = timeout_handler;
1446 	garmin_data_p->port = port;
1447 	garmin_data_p->state = 0;
1448 	garmin_data_p->count = 0;
1449 	usb_set_serial_port_data(port, garmin_data_p);
1450 
1451 	status = garmin_init_session(port);
1452 
1453 	return status;
1454 }
1455 
1456 
1457 static void garmin_shutdown (struct usb_serial *serial)
1458 {
1459 	struct usb_serial_port *port = serial->port[0];
1460 	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
1461 
1462 	dbg("%s", __FUNCTION__);
1463 
1464 	usb_kill_urb (port->interrupt_in_urb);
1465 	del_timer_sync(&garmin_data_p->timer);
1466 	kfree (garmin_data_p);
1467 	usb_set_serial_port_data(port, NULL);
1468 }
1469 
1470 
1471 
1472 
1473 
1474 
1475 
1476 /* All of the device info needed */
1477 static struct usb_serial_device_type garmin_device = {
1478 	.owner               = THIS_MODULE,
1479 	.name                = "Garmin GPS usb/tty",
1480 	.short_name          = "garmin_gps",
1481 	.id_table            = id_table,
1482 	.num_interrupt_in    = 1,
1483 	.num_bulk_in         = 1,
1484 	.num_bulk_out        = 1,
1485 	.num_ports           = 1,
1486 	.open                = garmin_open,
1487 	.close               = garmin_close,
1488 	.throttle            = garmin_throttle,
1489 	.unthrottle          = garmin_unthrottle,
1490 	.attach              = garmin_attach,
1491 	.shutdown            = garmin_shutdown,
1492 	.write               = garmin_write,
1493 	.write_room          = garmin_write_room,
1494 	.chars_in_buffer     = garmin_chars_in_buffer,
1495 	.write_bulk_callback = garmin_write_bulk_callback,
1496 	.read_bulk_callback  = garmin_read_bulk_callback,
1497 	.read_int_callback   = garmin_read_int_callback,
1498 };
1499 
1500 
1501 static int __init garmin_init (void)
1502 {
1503 	int retval;
1504 
1505 	retval = usb_serial_register(&garmin_device);
1506 	if (retval)
1507 		goto failed_garmin_register;
1508 	retval = usb_register(&garmin_driver);
1509 	if (retval)
1510 		goto failed_usb_register;
1511 	info(DRIVER_DESC " " DRIVER_VERSION);
1512 
1513 	return 0;
1514 failed_usb_register:
1515 	usb_serial_deregister(&garmin_device);
1516 failed_garmin_register:
1517 	return retval;
1518 }
1519 
1520 
1521 static void __exit garmin_exit (void)
1522 {
1523 	usb_deregister (&garmin_driver);
1524 	usb_serial_deregister (&garmin_device);
1525 }
1526 
1527 
1528 
1529 
1530 module_init(garmin_init);
1531 module_exit(garmin_exit);
1532 
1533 MODULE_AUTHOR( DRIVER_AUTHOR );
1534 MODULE_DESCRIPTION( DRIVER_DESC );
1535 MODULE_LICENSE("GPL");
1536 
1537 module_param(debug, bool, S_IWUSR | S_IRUGO);
1538 MODULE_PARM_DESC(debug, "Debug enabled or not");
1539 module_param(initial_mode, int, S_IRUGO);
1540 MODULE_PARM_DESC(initial_mode, "Initial mode");
1541 
1542