linux/drivers/usb/serial/garmin_gps.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Garmin GPS driver
   4 *
   5 * Copyright (C) 2006-2011 Hermann Kneissel herkne@gmx.de
   6 *
   7 * The latest version of the driver can be found at
   8 * http://sourceforge.net/projects/garmin-gps/
   9 *
  10 * This driver has been derived from v2.1 of the visor driver.
  11 */
  12
  13#include <linux/kernel.h>
  14#include <linux/errno.h>
  15#include <linux/slab.h>
  16#include <linux/timer.h>
  17#include <linux/tty.h>
  18#include <linux/tty_driver.h>
  19#include <linux/tty_flip.h>
  20#include <linux/module.h>
  21#include <linux/spinlock.h>
  22#include <linux/uaccess.h>
  23#include <linux/atomic.h>
  24#include <linux/usb.h>
  25#include <linux/usb/serial.h>
  26
  27/* the mode to be set when the port ist opened */
  28static int initial_mode = 1;
  29
  30#define GARMIN_VENDOR_ID             0x091E
  31
  32/*
  33 * Version Information
  34 */
  35
  36#define VERSION_MAJOR   0
  37#define VERSION_MINOR   36
  38
  39#define _STR(s) #s
  40#define _DRIVER_VERSION(a, b) "v" _STR(a) "." _STR(b)
  41#define DRIVER_VERSION _DRIVER_VERSION(VERSION_MAJOR, VERSION_MINOR)
  42#define DRIVER_AUTHOR "hermann kneissel"
  43#define DRIVER_DESC "garmin gps driver"
  44
  45/* error codes returned by the driver */
  46#define EINVPKT 1000    /* invalid packet structure */
  47
  48
  49/* size of the header of a packet using the usb protocol */
  50#define GARMIN_PKTHDR_LENGTH    12
  51
  52/* max. possible size of a packet using the serial protocol */
  53#define MAX_SERIAL_PKT_SIZ (3 + 255 + 3)
  54
  55/*  max. possible size of a packet with worst case stuffing */
  56#define MAX_SERIAL_PKT_SIZ_STUFFED (MAX_SERIAL_PKT_SIZ + 256)
  57
  58/* size of a buffer able to hold a complete (no stuffing) packet
  59 * (the document protocol does not contain packets with a larger
  60 *  size, but in theory a packet may be 64k+12 bytes - if in
  61 *  later protocol versions larger packet sizes occur, this value
  62 *  should be increased accordingly, so the input buffer is always
  63 *  large enough the store a complete packet inclusive header) */
  64#define GPS_IN_BUFSIZ  (GARMIN_PKTHDR_LENGTH+MAX_SERIAL_PKT_SIZ)
  65
  66/* size of a buffer able to hold a complete (incl. stuffing) packet */
  67#define GPS_OUT_BUFSIZ (GARMIN_PKTHDR_LENGTH+MAX_SERIAL_PKT_SIZ_STUFFED)
  68
  69/* where to place the packet id of a serial packet, so we can
  70 * prepend the usb-packet header without the need to move the
  71 * packets data */
  72#define GSP_INITIAL_OFFSET (GARMIN_PKTHDR_LENGTH-2)
  73
  74/* max. size of incoming private packets (header+1 param) */
  75#define PRIVPKTSIZ (GARMIN_PKTHDR_LENGTH+4)
  76
  77#define GARMIN_LAYERID_TRANSPORT  0
  78#define GARMIN_LAYERID_APPL      20
  79/* our own layer-id to use for some control mechanisms */
  80#define GARMIN_LAYERID_PRIVATE  0x01106E4B
  81
  82#define GARMIN_PKTID_PVT_DATA   51
  83#define GARMIN_PKTID_L001_COMMAND_DATA 10
  84
  85#define CMND_ABORT_TRANSFER 0
  86
  87/* packet ids used in private layer */
  88#define PRIV_PKTID_SET_DEBUG    1
  89#define PRIV_PKTID_SET_MODE     2
  90#define PRIV_PKTID_INFO_REQ     3
  91#define PRIV_PKTID_INFO_RESP    4
  92#define PRIV_PKTID_RESET_REQ    5
  93#define PRIV_PKTID_SET_DEF_MODE 6
  94
  95
  96#define ETX     0x03
  97#define DLE     0x10
  98#define ACK     0x06
  99#define NAK     0x15
 100
 101/* structure used to queue incoming packets */
 102struct garmin_packet {
 103        struct list_head  list;
 104        int               seq;
 105        /* the real size of the data array, always > 0 */
 106        int               size;
 107        __u8              data[];
 108};
 109
 110/* structure used to keep the current state of the driver */
 111struct garmin_data {
 112        __u8   state;
 113        __u16  flags;
 114        __u8   mode;
 115        __u8   count;
 116        __u8   pkt_id;
 117        __u32  serial_num;
 118        struct timer_list timer;
 119        struct usb_serial_port *port;
 120        int    seq_counter;
 121        int    insize;
 122        int    outsize;
 123        __u8   inbuffer [GPS_IN_BUFSIZ];  /* tty -> usb */
 124        __u8   outbuffer[GPS_OUT_BUFSIZ]; /* usb -> tty */
 125        __u8   privpkt[4*6];
 126        spinlock_t lock;
 127        struct list_head pktlist;
 128        struct usb_anchor write_urbs;
 129};
 130
 131
 132#define STATE_NEW            0
 133#define STATE_INITIAL_DELAY  1
 134#define STATE_TIMEOUT        2
 135#define STATE_SESSION_REQ1   3
 136#define STATE_SESSION_REQ2   4
 137#define STATE_ACTIVE         5
 138
 139#define STATE_RESET          8
 140#define STATE_DISCONNECTED   9
 141#define STATE_WAIT_TTY_ACK  10
 142#define STATE_GSP_WAIT_DATA 11
 143
 144#define MODE_NATIVE          0
 145#define MODE_GARMIN_SERIAL   1
 146
 147/* Flags used in garmin_data.flags: */
 148#define FLAGS_SESSION_REPLY_MASK  0x00C0
 149#define FLAGS_SESSION_REPLY1_SEEN 0x0080
 150#define FLAGS_SESSION_REPLY2_SEEN 0x0040
 151#define FLAGS_BULK_IN_ACTIVE      0x0020
 152#define FLAGS_BULK_IN_RESTART     0x0010
 153#define FLAGS_THROTTLED           0x0008
 154#define APP_REQ_SEEN              0x0004
 155#define APP_RESP_SEEN             0x0002
 156#define CLEAR_HALT_REQUIRED       0x0001
 157
 158#define FLAGS_QUEUING             0x0100
 159#define FLAGS_DROP_DATA           0x0800
 160
 161#define FLAGS_GSP_SKIP            0x1000
 162#define FLAGS_GSP_DLESEEN         0x2000
 163
 164
 165
 166
 167
 168
 169/* function prototypes */
 170static int gsp_next_packet(struct garmin_data *garmin_data_p);
 171static int garmin_write_bulk(struct usb_serial_port *port,
 172                             const unsigned char *buf, int count,
 173                             int dismiss_ack);
 174
 175/* some special packets to be send or received */
 176static unsigned char const GARMIN_START_SESSION_REQ[]
 177        = { 0, 0, 0, 0,  5, 0, 0, 0, 0, 0, 0, 0 };
 178static unsigned char const GARMIN_START_SESSION_REPLY[]
 179        = { 0, 0, 0, 0,  6, 0, 0, 0, 4, 0, 0, 0 };
 180static unsigned char const GARMIN_BULK_IN_AVAIL_REPLY[]
 181        = { 0, 0, 0, 0,  2, 0, 0, 0, 0, 0, 0, 0 };
 182static unsigned char const GARMIN_APP_LAYER_REPLY[]
 183        = { 0x14, 0, 0, 0 };
 184static unsigned char const GARMIN_START_PVT_REQ[]
 185        = { 20, 0, 0, 0,  10, 0, 0, 0, 2, 0, 0, 0, 49, 0 };
 186static unsigned char const GARMIN_STOP_PVT_REQ[]
 187        = { 20, 0, 0, 0,  10, 0, 0, 0, 2, 0, 0, 0, 50, 0 };
 188static unsigned char const GARMIN_STOP_TRANSFER_REQ[]
 189        = { 20, 0, 0, 0,  10, 0, 0, 0, 2, 0, 0, 0, 0, 0 };
 190static unsigned char const GARMIN_STOP_TRANSFER_REQ_V2[]
 191        = { 20, 0, 0, 0,  10, 0, 0, 0, 1, 0, 0, 0, 0 };
 192static unsigned char const PRIVATE_REQ[]
 193        =    { 0x4B, 0x6E, 0x10, 0x01,  0xFF, 0, 0, 0, 0xFF, 0, 0, 0 };
 194
 195
 196
 197static const struct usb_device_id id_table[] = {
 198        /* the same device id seems to be used by all
 199           usb enabled GPS devices */
 200        { USB_DEVICE(GARMIN_VENDOR_ID, 3) },
 201        { }                                     /* Terminating entry */
 202};
 203MODULE_DEVICE_TABLE(usb, id_table);
 204
 205
 206static inline int getLayerId(const __u8 *usbPacket)
 207{
 208        return __le32_to_cpup((__le32 *)(usbPacket));
 209}
 210
 211static inline int getPacketId(const __u8 *usbPacket)
 212{
 213        return __le32_to_cpup((__le32 *)(usbPacket+4));
 214}
 215
 216static inline int getDataLength(const __u8 *usbPacket)
 217{
 218        return __le32_to_cpup((__le32 *)(usbPacket+8));
 219}
 220
 221
 222/*
 223 * check if the usb-packet in buf contains an abort-transfer command.
 224 * (if yes, all queued data will be dropped)
 225 */
 226static inline int isAbortTrfCmnd(const unsigned char *buf)
 227{
 228        if (memcmp(buf, GARMIN_STOP_TRANSFER_REQ,
 229                        sizeof(GARMIN_STOP_TRANSFER_REQ)) == 0 ||
 230            memcmp(buf, GARMIN_STOP_TRANSFER_REQ_V2,
 231                        sizeof(GARMIN_STOP_TRANSFER_REQ_V2)) == 0)
 232                return 1;
 233        else
 234                return 0;
 235}
 236
 237
 238
 239static void send_to_tty(struct usb_serial_port *port,
 240                        char *data, unsigned int actual_length)
 241{
 242        if (actual_length) {
 243                usb_serial_debug_data(&port->dev, __func__, actual_length, data);
 244                tty_insert_flip_string(&port->port, data, actual_length);
 245                tty_flip_buffer_push(&port->port);
 246        }
 247}
 248
 249
 250/******************************************************************************
 251 * packet queue handling
 252 ******************************************************************************/
 253
 254/*
 255 * queue a received (usb-)packet for later processing
 256 */
 257static int pkt_add(struct garmin_data *garmin_data_p,
 258                   unsigned char *data, unsigned int data_length)
 259{
 260        int state = 0;
 261        int result = 0;
 262        unsigned long flags;
 263        struct garmin_packet *pkt;
 264
 265        /* process only packets containing data ... */
 266        if (data_length) {
 267                pkt = kmalloc(sizeof(struct garmin_packet)+data_length,
 268                                                                GFP_ATOMIC);
 269                if (!pkt)
 270                        return 0;
 271
 272                pkt->size = data_length;
 273                memcpy(pkt->data, data, data_length);
 274
 275                spin_lock_irqsave(&garmin_data_p->lock, flags);
 276                garmin_data_p->flags |= FLAGS_QUEUING;
 277                result = list_empty(&garmin_data_p->pktlist);
 278                pkt->seq = garmin_data_p->seq_counter++;
 279                list_add_tail(&pkt->list, &garmin_data_p->pktlist);
 280                state = garmin_data_p->state;
 281                spin_unlock_irqrestore(&garmin_data_p->lock, flags);
 282
 283                dev_dbg(&garmin_data_p->port->dev,
 284                        "%s - added: pkt: %d - %d bytes\n", __func__,
 285                        pkt->seq, data_length);
 286
 287                /* in serial mode, if someone is waiting for data from
 288                   the device, convert and send the next packet to tty. */
 289                if (result && (state == STATE_GSP_WAIT_DATA))
 290                        gsp_next_packet(garmin_data_p);
 291        }
 292        return result;
 293}
 294
 295
 296/* get the next pending packet */
 297static struct garmin_packet *pkt_pop(struct garmin_data *garmin_data_p)
 298{
 299        unsigned long flags;
 300        struct garmin_packet *result = NULL;
 301
 302        spin_lock_irqsave(&garmin_data_p->lock, flags);
 303        if (!list_empty(&garmin_data_p->pktlist)) {
 304                result = (struct garmin_packet *)garmin_data_p->pktlist.next;
 305                list_del(&result->list);
 306        }
 307        spin_unlock_irqrestore(&garmin_data_p->lock, flags);
 308        return result;
 309}
 310
 311
 312/* free up all queued data */
 313static void pkt_clear(struct garmin_data *garmin_data_p)
 314{
 315        unsigned long flags;
 316        struct garmin_packet *result = NULL;
 317
 318        spin_lock_irqsave(&garmin_data_p->lock, flags);
 319        while (!list_empty(&garmin_data_p->pktlist)) {
 320                result = (struct garmin_packet *)garmin_data_p->pktlist.next;
 321                list_del(&result->list);
 322                kfree(result);
 323        }
 324        spin_unlock_irqrestore(&garmin_data_p->lock, flags);
 325}
 326
 327
 328/******************************************************************************
 329 * garmin serial protocol handling handling
 330 ******************************************************************************/
 331
 332/* send an ack packet back to the tty */
 333static int gsp_send_ack(struct garmin_data *garmin_data_p, __u8 pkt_id)
 334{
 335        __u8 pkt[10];
 336        __u8 cksum = 0;
 337        __u8 *ptr = pkt;
 338        unsigned  l = 0;
 339
 340        dev_dbg(&garmin_data_p->port->dev, "%s - pkt-id: 0x%X.\n", __func__,
 341                        pkt_id);
 342
 343        *ptr++ = DLE;
 344        *ptr++ = ACK;
 345        cksum += ACK;
 346
 347        *ptr++ = 2;
 348        cksum += 2;
 349
 350        *ptr++ = pkt_id;
 351        cksum += pkt_id;
 352
 353        if (pkt_id == DLE)
 354                *ptr++ = DLE;
 355
 356        *ptr++ = 0;
 357        *ptr++ = (-cksum) & 0xFF;
 358        *ptr++ = DLE;
 359        *ptr++ = ETX;
 360
 361        l = ptr-pkt;
 362
 363        send_to_tty(garmin_data_p->port, pkt, l);
 364        return 0;
 365}
 366
 367
 368
 369/*
 370 * called for a complete packet received from tty layer
 371 *
 372 * the complete packet (pktid ... cksum) is in garmin_data_p->inbuf starting
 373 * at GSP_INITIAL_OFFSET.
 374 *
 375 * count - number of bytes in the input buffer including space reserved for
 376 *         the usb header: GSP_INITIAL_OFFSET + number of bytes in packet
 377 *         (including pkt-id, data-length a. cksum)
 378 */
 379static int gsp_rec_packet(struct garmin_data *garmin_data_p, int count)
 380{
 381        struct device *dev = &garmin_data_p->port->dev;
 382        unsigned long flags;
 383        const __u8 *recpkt = garmin_data_p->inbuffer+GSP_INITIAL_OFFSET;
 384        __le32 *usbdata = (__le32 *) garmin_data_p->inbuffer;
 385        int cksum = 0;
 386        int n = 0;
 387        int pktid = recpkt[0];
 388        int size = recpkt[1];
 389
 390        usb_serial_debug_data(&garmin_data_p->port->dev, __func__,
 391                              count-GSP_INITIAL_OFFSET, recpkt);
 392
 393        if (size != (count-GSP_INITIAL_OFFSET-3)) {
 394                dev_dbg(dev, "%s - invalid size, expected %d bytes, got %d\n",
 395                        __func__, size, (count-GSP_INITIAL_OFFSET-3));
 396                return -EINVPKT;
 397        }
 398
 399        cksum += *recpkt++;
 400        cksum += *recpkt++;
 401
 402        /* sanity check, remove after test ... */
 403        if ((__u8 *)&(usbdata[3]) != recpkt) {
 404                dev_dbg(dev, "%s - ptr mismatch %p - %p\n", __func__,
 405                        &(usbdata[4]), recpkt);
 406                return -EINVPKT;
 407        }
 408
 409        while (n < size) {
 410                cksum += *recpkt++;
 411                n++;
 412        }
 413
 414        if (((cksum + *recpkt) & 0xff) != 0) {
 415                dev_dbg(dev, "%s - invalid checksum, expected %02x, got %02x\n",
 416                        __func__, -cksum & 0xff, *recpkt);
 417                return -EINVPKT;
 418        }
 419
 420        usbdata[0] = __cpu_to_le32(GARMIN_LAYERID_APPL);
 421        usbdata[1] = __cpu_to_le32(pktid);
 422        usbdata[2] = __cpu_to_le32(size);
 423
 424        garmin_write_bulk(garmin_data_p->port, garmin_data_p->inbuffer,
 425                           GARMIN_PKTHDR_LENGTH+size, 0);
 426
 427        /* if this was an abort-transfer command, flush all
 428           queued data. */
 429        if (isAbortTrfCmnd(garmin_data_p->inbuffer)) {
 430                spin_lock_irqsave(&garmin_data_p->lock, flags);
 431                garmin_data_p->flags |= FLAGS_DROP_DATA;
 432                spin_unlock_irqrestore(&garmin_data_p->lock, flags);
 433                pkt_clear(garmin_data_p);
 434        }
 435
 436        return count;
 437}
 438
 439
 440
 441/*
 442 * Called for data received from tty
 443 *
 444 * buf contains the data read, it may span more than one packet or even
 445 * incomplete packets
 446 *
 447 * input record should be a serial-record, but it may not be complete.
 448 * Copy it into our local buffer, until an etx is seen (or an error
 449 * occurs).
 450 * Once the record is complete, convert into a usb packet and send it
 451 * to the bulk pipe, send an ack back to the tty.
 452 *
 453 * If the input is an ack, just send the last queued packet to the
 454 * tty layer.
 455 *
 456 * if the input is an abort command, drop all queued data.
 457 */
 458
 459static int gsp_receive(struct garmin_data *garmin_data_p,
 460                       const unsigned char *buf, int count)
 461{
 462        struct device *dev = &garmin_data_p->port->dev;
 463        unsigned long flags;
 464        int offs = 0;
 465        int ack_or_nak_seen = 0;
 466        __u8 *dest;
 467        int size;
 468        /* dleSeen: set if last byte read was a DLE */
 469        int dleSeen;
 470        /* skip: if set, skip incoming data until possible start of
 471         *       new packet
 472         */
 473        int skip;
 474        __u8 data;
 475
 476        spin_lock_irqsave(&garmin_data_p->lock, flags);
 477        dest = garmin_data_p->inbuffer;
 478        size = garmin_data_p->insize;
 479        dleSeen = garmin_data_p->flags & FLAGS_GSP_DLESEEN;
 480        skip = garmin_data_p->flags & FLAGS_GSP_SKIP;
 481        spin_unlock_irqrestore(&garmin_data_p->lock, flags);
 482
 483        /* dev_dbg(dev, "%s - dle=%d skip=%d size=%d count=%d\n",
 484                __func__, dleSeen, skip, size, count); */
 485
 486        if (size == 0)
 487                size = GSP_INITIAL_OFFSET;
 488
 489        while (offs < count) {
 490
 491                data = *(buf+offs);
 492                offs++;
 493
 494                if (data == DLE) {
 495                        if (skip) { /* start of a new pkt */
 496                                skip = 0;
 497                                size = GSP_INITIAL_OFFSET;
 498                                dleSeen = 1;
 499                        } else if (dleSeen) {
 500                                dest[size++] = data;
 501                                dleSeen = 0;
 502                        } else {
 503                                dleSeen = 1;
 504                        }
 505                } else if (data == ETX) {
 506                        if (dleSeen) {
 507                                /* packet complete */
 508
 509                                data = dest[GSP_INITIAL_OFFSET];
 510
 511                                if (data == ACK) {
 512                                        ack_or_nak_seen = ACK;
 513                                        dev_dbg(dev, "ACK packet complete.\n");
 514                                } else if (data == NAK) {
 515                                        ack_or_nak_seen = NAK;
 516                                        dev_dbg(dev, "NAK packet complete.\n");
 517                                } else {
 518                                        dev_dbg(dev, "packet complete - id=0x%X.\n",
 519                                                        data);
 520                                        gsp_rec_packet(garmin_data_p, size);
 521                                }
 522
 523                                skip = 1;
 524                                size = GSP_INITIAL_OFFSET;
 525                                dleSeen = 0;
 526                        } else {
 527                                dest[size++] = data;
 528                        }
 529                } else if (!skip) {
 530
 531                        if (dleSeen) {
 532                                size = GSP_INITIAL_OFFSET;
 533                                dleSeen = 0;
 534                        }
 535
 536                        dest[size++] = data;
 537                }
 538
 539                if (size >= GPS_IN_BUFSIZ) {
 540                        dev_dbg(dev, "%s - packet too large.\n", __func__);
 541                        skip = 1;
 542                        size = GSP_INITIAL_OFFSET;
 543                        dleSeen = 0;
 544                }
 545        }
 546
 547        spin_lock_irqsave(&garmin_data_p->lock, flags);
 548
 549        garmin_data_p->insize = size;
 550
 551        /* copy flags back to structure */
 552        if (skip)
 553                garmin_data_p->flags |= FLAGS_GSP_SKIP;
 554        else
 555                garmin_data_p->flags &= ~FLAGS_GSP_SKIP;
 556
 557        if (dleSeen)
 558                garmin_data_p->flags |= FLAGS_GSP_DLESEEN;
 559        else
 560                garmin_data_p->flags &= ~FLAGS_GSP_DLESEEN;
 561
 562        spin_unlock_irqrestore(&garmin_data_p->lock, flags);
 563
 564        if (ack_or_nak_seen) {
 565                if (gsp_next_packet(garmin_data_p) > 0)
 566                        garmin_data_p->state = STATE_ACTIVE;
 567                else
 568                        garmin_data_p->state = STATE_GSP_WAIT_DATA;
 569        }
 570        return count;
 571}
 572
 573
 574
 575/*
 576 * Sends a usb packet to the tty
 577 *
 578 * Assumes, that all packages and at an usb-packet boundary.
 579 *
 580 * return <0 on error, 0 if packet is incomplete or > 0 if packet was sent
 581 */
 582static int gsp_send(struct garmin_data *garmin_data_p,
 583                    const unsigned char *buf, int count)
 584{
 585        struct device *dev = &garmin_data_p->port->dev;
 586        const unsigned char *src;
 587        unsigned char *dst;
 588        int pktid = 0;
 589        int datalen = 0;
 590        int cksum = 0;
 591        int i = 0;
 592        int k;
 593
 594        dev_dbg(dev, "%s - state %d - %d bytes.\n", __func__,
 595                garmin_data_p->state, count);
 596
 597        k = garmin_data_p->outsize;
 598        if ((k+count) > GPS_OUT_BUFSIZ) {
 599                dev_dbg(dev, "packet too large\n");
 600                garmin_data_p->outsize = 0;
 601                return -4;
 602        }
 603
 604        memcpy(garmin_data_p->outbuffer+k, buf, count);
 605        k += count;
 606        garmin_data_p->outsize = k;
 607
 608        if (k >= GARMIN_PKTHDR_LENGTH) {
 609                pktid  = getPacketId(garmin_data_p->outbuffer);
 610                datalen = getDataLength(garmin_data_p->outbuffer);
 611                i = GARMIN_PKTHDR_LENGTH + datalen;
 612                if (k < i)
 613                        return 0;
 614        } else {
 615                return 0;
 616        }
 617
 618        dev_dbg(dev, "%s - %d bytes in buffer, %d bytes in pkt.\n", __func__, k, i);
 619
 620        /* garmin_data_p->outbuffer now contains a complete packet */
 621
 622        usb_serial_debug_data(&garmin_data_p->port->dev, __func__, k,
 623                              garmin_data_p->outbuffer);
 624
 625        garmin_data_p->outsize = 0;
 626
 627        if (getLayerId(garmin_data_p->outbuffer) != GARMIN_LAYERID_APPL) {
 628                dev_dbg(dev, "not an application packet (%d)\n",
 629                                getLayerId(garmin_data_p->outbuffer));
 630                return -1;
 631        }
 632
 633        if (pktid > 255) {
 634                dev_dbg(dev, "packet-id %d too large\n", pktid);
 635                return -2;
 636        }
 637
 638        if (datalen > 255) {
 639                dev_dbg(dev, "packet-size %d too large\n", datalen);
 640                return -3;
 641        }
 642
 643        /* the serial protocol should be able to handle this packet */
 644
 645        k = 0;
 646        src = garmin_data_p->outbuffer+GARMIN_PKTHDR_LENGTH;
 647        for (i = 0; i < datalen; i++) {
 648                if (*src++ == DLE)
 649                        k++;
 650        }
 651
 652        src = garmin_data_p->outbuffer+GARMIN_PKTHDR_LENGTH;
 653        if (k > (GARMIN_PKTHDR_LENGTH-2)) {
 654                /* can't add stuffing DLEs in place, move data to end
 655                   of buffer ... */
 656                dst = garmin_data_p->outbuffer+GPS_OUT_BUFSIZ-datalen;
 657                memcpy(dst, src, datalen);
 658                src = dst;
 659        }
 660
 661        dst = garmin_data_p->outbuffer;
 662
 663        *dst++ = DLE;
 664        *dst++ = pktid;
 665        cksum += pktid;
 666        *dst++ = datalen;
 667        cksum += datalen;
 668        if (datalen == DLE)
 669                *dst++ = DLE;
 670
 671        for (i = 0; i < datalen; i++) {
 672                __u8 c = *src++;
 673                *dst++ = c;
 674                cksum += c;
 675                if (c == DLE)
 676                        *dst++ = DLE;
 677        }
 678
 679        cksum = -cksum & 0xFF;
 680        *dst++ = cksum;
 681        if (cksum == DLE)
 682                *dst++ = DLE;
 683        *dst++ = DLE;
 684        *dst++ = ETX;
 685
 686        i = dst-garmin_data_p->outbuffer;
 687
 688        send_to_tty(garmin_data_p->port, garmin_data_p->outbuffer, i);
 689
 690        garmin_data_p->pkt_id = pktid;
 691        garmin_data_p->state  = STATE_WAIT_TTY_ACK;
 692
 693        return i;
 694}
 695
 696
 697/*
 698 * Process the next pending data packet - if there is one
 699 */
 700static int gsp_next_packet(struct garmin_data *garmin_data_p)
 701{
 702        int result = 0;
 703        struct garmin_packet *pkt = NULL;
 704
 705        while ((pkt = pkt_pop(garmin_data_p)) != NULL) {
 706                dev_dbg(&garmin_data_p->port->dev, "%s - next pkt: %d\n", __func__, pkt->seq);
 707                result = gsp_send(garmin_data_p, pkt->data, pkt->size);
 708                if (result > 0) {
 709                        kfree(pkt);
 710                        return result;
 711                }
 712                kfree(pkt);
 713        }
 714        return result;
 715}
 716
 717
 718
 719/******************************************************************************
 720 * garmin native mode
 721 ******************************************************************************/
 722
 723
 724/*
 725 * Called for data received from tty
 726 *
 727 * The input data is expected to be in garmin usb-packet format.
 728 *
 729 * buf contains the data read, it may span more than one packet
 730 * or even incomplete packets
 731 */
 732static int nat_receive(struct garmin_data *garmin_data_p,
 733                       const unsigned char *buf, int count)
 734{
 735        unsigned long flags;
 736        __u8 *dest;
 737        int offs = 0;
 738        int result = count;
 739        int len;
 740
 741        while (offs < count) {
 742                /* if buffer contains header, copy rest of data */
 743                if (garmin_data_p->insize >= GARMIN_PKTHDR_LENGTH)
 744                        len = GARMIN_PKTHDR_LENGTH
 745                              +getDataLength(garmin_data_p->inbuffer);
 746                else
 747                        len = GARMIN_PKTHDR_LENGTH;
 748
 749                if (len >= GPS_IN_BUFSIZ) {
 750                        /* seems to be an invalid packet, ignore rest
 751                           of input */
 752                        dev_dbg(&garmin_data_p->port->dev,
 753                                "%s - packet size too large: %d\n",
 754                                __func__, len);
 755                        garmin_data_p->insize = 0;
 756                        count = 0;
 757                        result = -EINVPKT;
 758                } else {
 759                        len -= garmin_data_p->insize;
 760                        if (len > (count-offs))
 761                                len = (count-offs);
 762                        if (len > 0) {
 763                                dest = garmin_data_p->inbuffer
 764                                                + garmin_data_p->insize;
 765                                memcpy(dest, buf+offs, len);
 766                                garmin_data_p->insize += len;
 767                                offs += len;
 768                        }
 769                }
 770
 771                /* do we have a complete packet ? */
 772                if (garmin_data_p->insize >= GARMIN_PKTHDR_LENGTH) {
 773                        len = GARMIN_PKTHDR_LENGTH+
 774                           getDataLength(garmin_data_p->inbuffer);
 775                        if (garmin_data_p->insize >= len) {
 776                                garmin_write_bulk(garmin_data_p->port,
 777                                                   garmin_data_p->inbuffer,
 778                                                   len, 0);
 779                                garmin_data_p->insize = 0;
 780
 781                                /* if this was an abort-transfer command,
 782                                   flush all queued data. */
 783                                if (isAbortTrfCmnd(garmin_data_p->inbuffer)) {
 784                                        spin_lock_irqsave(&garmin_data_p->lock,
 785                                                                        flags);
 786                                        garmin_data_p->flags |= FLAGS_DROP_DATA;
 787                                        spin_unlock_irqrestore(
 788                                                &garmin_data_p->lock, flags);
 789                                        pkt_clear(garmin_data_p);
 790                                }
 791                        }
 792                }
 793        }
 794        return result;
 795}
 796
 797
 798/******************************************************************************
 799 * private packets
 800 ******************************************************************************/
 801
 802static void priv_status_resp(struct usb_serial_port *port)
 803{
 804        struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
 805        __le32 *pkt = (__le32 *)garmin_data_p->privpkt;
 806
 807        pkt[0] = __cpu_to_le32(GARMIN_LAYERID_PRIVATE);
 808        pkt[1] = __cpu_to_le32(PRIV_PKTID_INFO_RESP);
 809        pkt[2] = __cpu_to_le32(12);
 810        pkt[3] = __cpu_to_le32(VERSION_MAJOR << 16 | VERSION_MINOR);
 811        pkt[4] = __cpu_to_le32(garmin_data_p->mode);
 812        pkt[5] = __cpu_to_le32(garmin_data_p->serial_num);
 813
 814        send_to_tty(port, (__u8 *)pkt, 6 * 4);
 815}
 816
 817
 818/******************************************************************************
 819 * Garmin specific driver functions
 820 ******************************************************************************/
 821
 822static int process_resetdev_request(struct usb_serial_port *port)
 823{
 824        unsigned long flags;
 825        int status;
 826        struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
 827
 828        spin_lock_irqsave(&garmin_data_p->lock, flags);
 829        garmin_data_p->flags &= ~(CLEAR_HALT_REQUIRED);
 830        garmin_data_p->state = STATE_RESET;
 831        garmin_data_p->serial_num = 0;
 832        spin_unlock_irqrestore(&garmin_data_p->lock, flags);
 833
 834        usb_kill_urb(port->interrupt_in_urb);
 835        dev_dbg(&port->dev, "%s - usb_reset_device\n", __func__);
 836        status = usb_reset_device(port->serial->dev);
 837        if (status)
 838                dev_dbg(&port->dev, "%s - usb_reset_device failed: %d\n",
 839                        __func__, status);
 840        return status;
 841}
 842
 843
 844
 845/*
 846 * clear all cached data
 847 */
 848static int garmin_clear(struct garmin_data *garmin_data_p)
 849{
 850        unsigned long flags;
 851
 852        /* flush all queued data */
 853        pkt_clear(garmin_data_p);
 854
 855        spin_lock_irqsave(&garmin_data_p->lock, flags);
 856        garmin_data_p->insize = 0;
 857        garmin_data_p->outsize = 0;
 858        spin_unlock_irqrestore(&garmin_data_p->lock, flags);
 859
 860        return 0;
 861}
 862
 863
 864static int garmin_init_session(struct usb_serial_port *port)
 865{
 866        struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
 867        int status;
 868        int i;
 869
 870        usb_kill_urb(port->interrupt_in_urb);
 871
 872        status = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
 873        if (status) {
 874                dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
 875                                status);
 876                return status;
 877        }
 878
 879        /*
 880         * using the initialization method from gpsbabel. See comments in
 881         * gpsbabel/jeeps/gpslibusb.c gusb_reset_toggles()
 882         */
 883        dev_dbg(&port->dev, "%s - starting session ...\n", __func__);
 884        garmin_data_p->state = STATE_ACTIVE;
 885
 886        for (i = 0; i < 3; i++) {
 887                status = garmin_write_bulk(port, GARMIN_START_SESSION_REQ,
 888                                sizeof(GARMIN_START_SESSION_REQ), 0);
 889                if (status < 0)
 890                        goto err_kill_urbs;
 891        }
 892
 893        return 0;
 894
 895err_kill_urbs:
 896        usb_kill_anchored_urbs(&garmin_data_p->write_urbs);
 897        usb_kill_urb(port->interrupt_in_urb);
 898
 899        return status;
 900}
 901
 902
 903
 904static int garmin_open(struct tty_struct *tty, struct usb_serial_port *port)
 905{
 906        unsigned long flags;
 907        int status = 0;
 908        struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
 909
 910        spin_lock_irqsave(&garmin_data_p->lock, flags);
 911        garmin_data_p->mode  = initial_mode;
 912        garmin_data_p->count = 0;
 913        garmin_data_p->flags &= FLAGS_SESSION_REPLY1_SEEN;
 914        spin_unlock_irqrestore(&garmin_data_p->lock, flags);
 915
 916        /* shutdown any bulk reads that might be going on */
 917        usb_kill_urb(port->read_urb);
 918
 919        if (garmin_data_p->state == STATE_RESET)
 920                status = garmin_init_session(port);
 921
 922        garmin_data_p->state = STATE_ACTIVE;
 923        return status;
 924}
 925
 926
 927static void garmin_close(struct usb_serial_port *port)
 928{
 929        struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
 930
 931        dev_dbg(&port->dev, "%s - mode=%d state=%d flags=0x%X\n",
 932                __func__, garmin_data_p->mode, garmin_data_p->state,
 933                garmin_data_p->flags);
 934
 935        garmin_clear(garmin_data_p);
 936
 937        /* shutdown our urbs */
 938        usb_kill_urb(port->read_urb);
 939        usb_kill_anchored_urbs(&garmin_data_p->write_urbs);
 940
 941        /* keep reset state so we know that we must start a new session */
 942        if (garmin_data_p->state != STATE_RESET)
 943                garmin_data_p->state = STATE_DISCONNECTED;
 944}
 945
 946
 947static void garmin_write_bulk_callback(struct urb *urb)
 948{
 949        struct usb_serial_port *port = urb->context;
 950
 951        if (port) {
 952                struct garmin_data *garmin_data_p =
 953                                        usb_get_serial_port_data(port);
 954
 955                if (getLayerId(urb->transfer_buffer) == GARMIN_LAYERID_APPL) {
 956
 957                        if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
 958                                gsp_send_ack(garmin_data_p,
 959                                        ((__u8 *)urb->transfer_buffer)[4]);
 960                        }
 961                }
 962                usb_serial_port_softint(port);
 963        }
 964
 965        /* Ignore errors that resulted from garmin_write_bulk with
 966           dismiss_ack = 1 */
 967
 968        /* free up the transfer buffer, as usb_free_urb() does not do this */
 969        kfree(urb->transfer_buffer);
 970}
 971
 972
 973static int garmin_write_bulk(struct usb_serial_port *port,
 974                              const unsigned char *buf, int count,
 975                              int dismiss_ack)
 976{
 977        unsigned long flags;
 978        struct usb_serial *serial = port->serial;
 979        struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
 980        struct urb *urb;
 981        unsigned char *buffer;
 982        int status;
 983
 984        spin_lock_irqsave(&garmin_data_p->lock, flags);
 985        garmin_data_p->flags &= ~FLAGS_DROP_DATA;
 986        spin_unlock_irqrestore(&garmin_data_p->lock, flags);
 987
 988        buffer = kmalloc(count, GFP_ATOMIC);
 989        if (!buffer)
 990                return -ENOMEM;
 991
 992        urb = usb_alloc_urb(0, GFP_ATOMIC);
 993        if (!urb) {
 994                kfree(buffer);
 995                return -ENOMEM;
 996        }
 997
 998        memcpy(buffer, buf, count);
 999
1000        usb_serial_debug_data(&port->dev, __func__, count, buffer);
1001
1002        usb_fill_bulk_urb(urb, serial->dev,
1003                                usb_sndbulkpipe(serial->dev,
1004                                        port->bulk_out_endpointAddress),
1005                                buffer, count,
1006                                garmin_write_bulk_callback,
1007                                dismiss_ack ? NULL : port);
1008        urb->transfer_flags |= URB_ZERO_PACKET;
1009
1010        if (getLayerId(buffer) == GARMIN_LAYERID_APPL) {
1011
1012                spin_lock_irqsave(&garmin_data_p->lock, flags);
1013                garmin_data_p->flags |= APP_REQ_SEEN;
1014                spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1015
1016                if (garmin_data_p->mode == MODE_GARMIN_SERIAL)  {
1017                        pkt_clear(garmin_data_p);
1018                        garmin_data_p->state = STATE_GSP_WAIT_DATA;
1019                }
1020        }
1021
1022        /* send it down the pipe */
1023        usb_anchor_urb(urb, &garmin_data_p->write_urbs);
1024        status = usb_submit_urb(urb, GFP_ATOMIC);
1025        if (status) {
1026                dev_err(&port->dev,
1027                   "%s - usb_submit_urb(write bulk) failed with status = %d\n",
1028                                __func__, status);
1029                count = status;
1030                usb_unanchor_urb(urb);
1031                kfree(buffer);
1032        }
1033
1034        /* we are done with this urb, so let the host driver
1035         * really free it when it is finished with it */
1036        usb_free_urb(urb);
1037
1038        return count;
1039}
1040
1041static int garmin_write(struct tty_struct *tty, struct usb_serial_port *port,
1042                                         const unsigned char *buf, int count)
1043{
1044        struct device *dev = &port->dev;
1045        int pktid, pktsiz, len;
1046        struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1047        __le32 *privpkt = (__le32 *)garmin_data_p->privpkt;
1048
1049        usb_serial_debug_data(dev, __func__, count, buf);
1050
1051        if (garmin_data_p->state == STATE_RESET)
1052                return -EIO;
1053
1054        /* check for our private packets */
1055        if (count >= GARMIN_PKTHDR_LENGTH) {
1056                len = PRIVPKTSIZ;
1057                if (count < len)
1058                        len = count;
1059
1060                memcpy(garmin_data_p->privpkt, buf, len);
1061
1062                pktsiz = getDataLength(garmin_data_p->privpkt);
1063                pktid  = getPacketId(garmin_data_p->privpkt);
1064
1065                if (count == (GARMIN_PKTHDR_LENGTH + pktsiz) &&
1066                                getLayerId(garmin_data_p->privpkt) ==
1067                                                GARMIN_LAYERID_PRIVATE) {
1068
1069                        dev_dbg(dev, "%s - processing private request %d\n",
1070                                __func__, pktid);
1071
1072                        /* drop all unfinished transfers */
1073                        garmin_clear(garmin_data_p);
1074
1075                        switch (pktid) {
1076                        case PRIV_PKTID_SET_MODE:
1077                                if (pktsiz != 4)
1078                                        return -EINVPKT;
1079                                garmin_data_p->mode = __le32_to_cpu(privpkt[3]);
1080                                dev_dbg(dev, "%s - mode set to %d\n",
1081                                        __func__, garmin_data_p->mode);
1082                                break;
1083
1084                        case PRIV_PKTID_INFO_REQ:
1085                                priv_status_resp(port);
1086                                break;
1087
1088                        case PRIV_PKTID_RESET_REQ:
1089                                process_resetdev_request(port);
1090                                break;
1091
1092                        case PRIV_PKTID_SET_DEF_MODE:
1093                                if (pktsiz != 4)
1094                                        return -EINVPKT;
1095                                initial_mode = __le32_to_cpu(privpkt[3]);
1096                                dev_dbg(dev, "%s - initial_mode set to %d\n",
1097                                        __func__,
1098                                        garmin_data_p->mode);
1099                                break;
1100                        }
1101                        return count;
1102                }
1103        }
1104
1105        if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
1106                return gsp_receive(garmin_data_p, buf, count);
1107        } else {        /* MODE_NATIVE */
1108                return nat_receive(garmin_data_p, buf, count);
1109        }
1110}
1111
1112
1113static int garmin_write_room(struct tty_struct *tty)
1114{
1115        struct usb_serial_port *port = tty->driver_data;
1116        /*
1117         * Report back the bytes currently available in the output buffer.
1118         */
1119        struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1120        return GPS_OUT_BUFSIZ-garmin_data_p->outsize;
1121}
1122
1123
1124static void garmin_read_process(struct garmin_data *garmin_data_p,
1125                                 unsigned char *data, unsigned data_length,
1126                                 int bulk_data)
1127{
1128        unsigned long flags;
1129
1130        if (garmin_data_p->flags & FLAGS_DROP_DATA) {
1131                /* abort-transfer cmd is active */
1132                dev_dbg(&garmin_data_p->port->dev, "%s - pkt dropped\n", __func__);
1133        } else if (garmin_data_p->state != STATE_DISCONNECTED &&
1134                garmin_data_p->state != STATE_RESET) {
1135
1136                /* if throttling is active or postprecessing is required
1137                   put the received data in the input queue, otherwise
1138                   send it directly to the tty port */
1139                if (garmin_data_p->flags & FLAGS_QUEUING) {
1140                        pkt_add(garmin_data_p, data, data_length);
1141                } else if (bulk_data || (data_length >= sizeof(u32) &&
1142                                getLayerId(data) == GARMIN_LAYERID_APPL)) {
1143
1144                        spin_lock_irqsave(&garmin_data_p->lock, flags);
1145                        garmin_data_p->flags |= APP_RESP_SEEN;
1146                        spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1147
1148                        if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
1149                                pkt_add(garmin_data_p, data, data_length);
1150                        } else {
1151                                send_to_tty(garmin_data_p->port, data,
1152                                                data_length);
1153                        }
1154                }
1155                /* ignore system layer packets ... */
1156        }
1157}
1158
1159
1160static void garmin_read_bulk_callback(struct urb *urb)
1161{
1162        unsigned long flags;
1163        struct usb_serial_port *port = urb->context;
1164        struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1165        unsigned char *data = urb->transfer_buffer;
1166        int status = urb->status;
1167        int retval;
1168
1169        if (status) {
1170                dev_dbg(&urb->dev->dev, "%s - nonzero read bulk status received: %d\n",
1171                        __func__, status);
1172                return;
1173        }
1174
1175        usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
1176
1177        garmin_read_process(garmin_data_p, data, urb->actual_length, 1);
1178
1179        if (urb->actual_length == 0 &&
1180                        (garmin_data_p->flags & FLAGS_BULK_IN_RESTART) != 0) {
1181                spin_lock_irqsave(&garmin_data_p->lock, flags);
1182                garmin_data_p->flags &= ~FLAGS_BULK_IN_RESTART;
1183                spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1184                retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
1185                if (retval)
1186                        dev_err(&port->dev,
1187                                "%s - failed resubmitting read urb, error %d\n",
1188                                __func__, retval);
1189        } else if (urb->actual_length > 0) {
1190                /* Continue trying to read until nothing more is received  */
1191                if ((garmin_data_p->flags & FLAGS_THROTTLED) == 0) {
1192                        retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
1193                        if (retval)
1194                                dev_err(&port->dev,
1195                                        "%s - failed resubmitting read urb, error %d\n",
1196                                        __func__, retval);
1197                }
1198        } else {
1199                dev_dbg(&port->dev, "%s - end of bulk data\n", __func__);
1200                spin_lock_irqsave(&garmin_data_p->lock, flags);
1201                garmin_data_p->flags &= ~FLAGS_BULK_IN_ACTIVE;
1202                spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1203        }
1204}
1205
1206
1207static void garmin_read_int_callback(struct urb *urb)
1208{
1209        unsigned long flags;
1210        int retval;
1211        struct usb_serial_port *port = urb->context;
1212        struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1213        unsigned char *data = urb->transfer_buffer;
1214        int status = urb->status;
1215
1216        switch (status) {
1217        case 0:
1218                /* success */
1219                break;
1220        case -ECONNRESET:
1221        case -ENOENT:
1222        case -ESHUTDOWN:
1223                /* this urb is terminated, clean up */
1224                dev_dbg(&urb->dev->dev, "%s - urb shutting down with status: %d\n",
1225                        __func__, status);
1226                return;
1227        default:
1228                dev_dbg(&urb->dev->dev, "%s - nonzero urb status received: %d\n",
1229                        __func__, status);
1230                return;
1231        }
1232
1233        usb_serial_debug_data(&port->dev, __func__, urb->actual_length,
1234                              urb->transfer_buffer);
1235
1236        if (urb->actual_length == sizeof(GARMIN_BULK_IN_AVAIL_REPLY) &&
1237                memcmp(data, GARMIN_BULK_IN_AVAIL_REPLY,
1238                                sizeof(GARMIN_BULK_IN_AVAIL_REPLY)) == 0) {
1239
1240                dev_dbg(&port->dev, "%s - bulk data available.\n", __func__);
1241
1242                if ((garmin_data_p->flags & FLAGS_BULK_IN_ACTIVE) == 0) {
1243
1244                        /* bulk data available */
1245                        retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
1246                        if (retval) {
1247                                dev_err(&port->dev,
1248                                 "%s - failed submitting read urb, error %d\n",
1249                                                        __func__, retval);
1250                        } else {
1251                                spin_lock_irqsave(&garmin_data_p->lock, flags);
1252                                garmin_data_p->flags |= FLAGS_BULK_IN_ACTIVE;
1253                                spin_unlock_irqrestore(&garmin_data_p->lock,
1254                                                                        flags);
1255                        }
1256                } else {
1257                        /* bulk-in transfer still active */
1258                        spin_lock_irqsave(&garmin_data_p->lock, flags);
1259                        garmin_data_p->flags |= FLAGS_BULK_IN_RESTART;
1260                        spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1261                }
1262
1263        } else if (urb->actual_length == (4+sizeof(GARMIN_START_SESSION_REPLY))
1264                         && memcmp(data, GARMIN_START_SESSION_REPLY,
1265                                 sizeof(GARMIN_START_SESSION_REPLY)) == 0) {
1266
1267                spin_lock_irqsave(&garmin_data_p->lock, flags);
1268                garmin_data_p->flags |= FLAGS_SESSION_REPLY1_SEEN;
1269                spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1270
1271                /* save the serial number */
1272                garmin_data_p->serial_num = __le32_to_cpup(
1273                                        (__le32 *)(data+GARMIN_PKTHDR_LENGTH));
1274
1275                dev_dbg(&port->dev, "%s - start-of-session reply seen - serial %u.\n",
1276                        __func__, garmin_data_p->serial_num);
1277        }
1278
1279        garmin_read_process(garmin_data_p, data, urb->actual_length, 0);
1280
1281        retval = usb_submit_urb(urb, GFP_ATOMIC);
1282        if (retval)
1283                dev_err(&urb->dev->dev,
1284                        "%s - Error %d submitting interrupt urb\n",
1285                        __func__, retval);
1286}
1287
1288
1289/*
1290 * Sends the next queued packt to the tty port (garmin native mode only)
1291 * and then sets a timer to call itself again until all queued data
1292 * is sent.
1293 */
1294static int garmin_flush_queue(struct garmin_data *garmin_data_p)
1295{
1296        unsigned long flags;
1297        struct garmin_packet *pkt;
1298
1299        if ((garmin_data_p->flags & FLAGS_THROTTLED) == 0) {
1300                pkt = pkt_pop(garmin_data_p);
1301                if (pkt != NULL) {
1302                        send_to_tty(garmin_data_p->port, pkt->data, pkt->size);
1303                        kfree(pkt);
1304                        mod_timer(&garmin_data_p->timer, (1)+jiffies);
1305
1306                } else {
1307                        spin_lock_irqsave(&garmin_data_p->lock, flags);
1308                        garmin_data_p->flags &= ~FLAGS_QUEUING;
1309                        spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1310                }
1311        }
1312        return 0;
1313}
1314
1315
1316static void garmin_throttle(struct tty_struct *tty)
1317{
1318        struct usb_serial_port *port = tty->driver_data;
1319        struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1320
1321        /* set flag, data received will be put into a queue
1322           for later processing */
1323        spin_lock_irq(&garmin_data_p->lock);
1324        garmin_data_p->flags |= FLAGS_QUEUING|FLAGS_THROTTLED;
1325        spin_unlock_irq(&garmin_data_p->lock);
1326}
1327
1328
1329static void garmin_unthrottle(struct tty_struct *tty)
1330{
1331        struct usb_serial_port *port = tty->driver_data;
1332        struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1333        int status;
1334
1335        spin_lock_irq(&garmin_data_p->lock);
1336        garmin_data_p->flags &= ~FLAGS_THROTTLED;
1337        spin_unlock_irq(&garmin_data_p->lock);
1338
1339        /* in native mode send queued data to tty, in
1340           serial mode nothing needs to be done here */
1341        if (garmin_data_p->mode == MODE_NATIVE)
1342                garmin_flush_queue(garmin_data_p);
1343
1344        if ((garmin_data_p->flags & FLAGS_BULK_IN_ACTIVE) != 0) {
1345                status = usb_submit_urb(port->read_urb, GFP_KERNEL);
1346                if (status)
1347                        dev_err(&port->dev,
1348                                "%s - failed resubmitting read urb, error %d\n",
1349                                __func__, status);
1350        }
1351}
1352
1353/*
1354 * The timer is currently only used to send queued packets to
1355 * the tty in cases where the protocol provides no own handshaking
1356 * to initiate the transfer.
1357 */
1358static void timeout_handler(struct timer_list *t)
1359{
1360        struct garmin_data *garmin_data_p = from_timer(garmin_data_p, t, timer);
1361
1362        /* send the next queued packet to the tty port */
1363        if (garmin_data_p->mode == MODE_NATIVE)
1364                if (garmin_data_p->flags & FLAGS_QUEUING)
1365                        garmin_flush_queue(garmin_data_p);
1366}
1367
1368
1369
1370static int garmin_port_probe(struct usb_serial_port *port)
1371{
1372        int status;
1373        struct garmin_data *garmin_data_p;
1374
1375        garmin_data_p = kzalloc(sizeof(struct garmin_data), GFP_KERNEL);
1376        if (!garmin_data_p)
1377                return -ENOMEM;
1378
1379        timer_setup(&garmin_data_p->timer, timeout_handler, 0);
1380        spin_lock_init(&garmin_data_p->lock);
1381        INIT_LIST_HEAD(&garmin_data_p->pktlist);
1382        garmin_data_p->port = port;
1383        garmin_data_p->state = 0;
1384        garmin_data_p->flags = 0;
1385        garmin_data_p->count = 0;
1386        init_usb_anchor(&garmin_data_p->write_urbs);
1387        usb_set_serial_port_data(port, garmin_data_p);
1388
1389        status = garmin_init_session(port);
1390        if (status)
1391                goto err_free;
1392
1393        return 0;
1394err_free:
1395        kfree(garmin_data_p);
1396
1397        return status;
1398}
1399
1400
1401static int garmin_port_remove(struct usb_serial_port *port)
1402{
1403        struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1404
1405        usb_kill_anchored_urbs(&garmin_data_p->write_urbs);
1406        usb_kill_urb(port->interrupt_in_urb);
1407        del_timer_sync(&garmin_data_p->timer);
1408        kfree(garmin_data_p);
1409        return 0;
1410}
1411
1412
1413/* All of the device info needed */
1414static struct usb_serial_driver garmin_device = {
1415        .driver = {
1416                .owner       = THIS_MODULE,
1417                .name        = "garmin_gps",
1418        },
1419        .description         = "Garmin GPS usb/tty",
1420        .id_table            = id_table,
1421        .num_ports           = 1,
1422        .open                = garmin_open,
1423        .close               = garmin_close,
1424        .throttle            = garmin_throttle,
1425        .unthrottle          = garmin_unthrottle,
1426        .port_probe             = garmin_port_probe,
1427        .port_remove            = garmin_port_remove,
1428        .write               = garmin_write,
1429        .write_room          = garmin_write_room,
1430        .write_bulk_callback = garmin_write_bulk_callback,
1431        .read_bulk_callback  = garmin_read_bulk_callback,
1432        .read_int_callback   = garmin_read_int_callback,
1433};
1434
1435static struct usb_serial_driver * const serial_drivers[] = {
1436        &garmin_device, NULL
1437};
1438
1439module_usb_serial_driver(serial_drivers, id_table);
1440
1441MODULE_AUTHOR(DRIVER_AUTHOR);
1442MODULE_DESCRIPTION(DRIVER_DESC);
1443MODULE_LICENSE("GPL");
1444
1445module_param(initial_mode, int, S_IRUGO);
1446MODULE_PARM_DESC(initial_mode, "Initial mode");
1447