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0001 // SPDX-License-Identifier: GPL-2.0+
0002 /*
0003  * Garmin GPS driver
0004  *
0005  * Copyright (C) 2006-2011 Hermann Kneissel herkne@gmx.de
0006  *
0007  * The latest version of the driver can be found at
0008  * http://sourceforge.net/projects/garmin-gps/
0009  *
0010  * This driver has been derived from v2.1 of the visor driver.
0011  */
0012 
0013 #include <linux/kernel.h>
0014 #include <linux/errno.h>
0015 #include <linux/slab.h>
0016 #include <linux/timer.h>
0017 #include <linux/tty.h>
0018 #include <linux/tty_driver.h>
0019 #include <linux/tty_flip.h>
0020 #include <linux/module.h>
0021 #include <linux/spinlock.h>
0022 #include <linux/uaccess.h>
0023 #include <linux/atomic.h>
0024 #include <linux/usb.h>
0025 #include <linux/usb/serial.h>
0026 
0027 /* the mode to be set when the port ist opened */
0028 static int initial_mode = 1;
0029 
0030 #define GARMIN_VENDOR_ID             0x091E
0031 
0032 /*
0033  * Version Information
0034  */
0035 
0036 #define VERSION_MAJOR   0
0037 #define VERSION_MINOR   36
0038 
0039 #define _STR(s) #s
0040 #define _DRIVER_VERSION(a, b) "v" _STR(a) "." _STR(b)
0041 #define DRIVER_VERSION _DRIVER_VERSION(VERSION_MAJOR, VERSION_MINOR)
0042 #define DRIVER_AUTHOR "hermann kneissel"
0043 #define DRIVER_DESC "garmin gps driver"
0044 
0045 /* error codes returned by the driver */
0046 #define EINVPKT 1000    /* invalid packet structure */
0047 
0048 
0049 /* size of the header of a packet using the usb protocol */
0050 #define GARMIN_PKTHDR_LENGTH    12
0051 
0052 /* max. possible size of a packet using the serial protocol */
0053 #define MAX_SERIAL_PKT_SIZ (3 + 255 + 3)
0054 
0055 /*  max. possible size of a packet with worst case stuffing */
0056 #define MAX_SERIAL_PKT_SIZ_STUFFED (MAX_SERIAL_PKT_SIZ + 256)
0057 
0058 /* size of a buffer able to hold a complete (no stuffing) packet
0059  * (the document protocol does not contain packets with a larger
0060  *  size, but in theory a packet may be 64k+12 bytes - if in
0061  *  later protocol versions larger packet sizes occur, this value
0062  *  should be increased accordingly, so the input buffer is always
0063  *  large enough the store a complete packet inclusive header) */
0064 #define GPS_IN_BUFSIZ  (GARMIN_PKTHDR_LENGTH+MAX_SERIAL_PKT_SIZ)
0065 
0066 /* size of a buffer able to hold a complete (incl. stuffing) packet */
0067 #define GPS_OUT_BUFSIZ (GARMIN_PKTHDR_LENGTH+MAX_SERIAL_PKT_SIZ_STUFFED)
0068 
0069 /* where to place the packet id of a serial packet, so we can
0070  * prepend the usb-packet header without the need to move the
0071  * packets data */
0072 #define GSP_INITIAL_OFFSET (GARMIN_PKTHDR_LENGTH-2)
0073 
0074 /* max. size of incoming private packets (header+1 param) */
0075 #define PRIVPKTSIZ (GARMIN_PKTHDR_LENGTH+4)
0076 
0077 #define GARMIN_LAYERID_TRANSPORT  0
0078 #define GARMIN_LAYERID_APPL      20
0079 /* our own layer-id to use for some control mechanisms */
0080 #define GARMIN_LAYERID_PRIVATE  0x01106E4B
0081 
0082 #define GARMIN_PKTID_PVT_DATA   51
0083 #define GARMIN_PKTID_L001_COMMAND_DATA 10
0084 
0085 #define CMND_ABORT_TRANSFER 0
0086 
0087 /* packet ids used in private layer */
0088 #define PRIV_PKTID_SET_DEBUG    1
0089 #define PRIV_PKTID_SET_MODE 2
0090 #define PRIV_PKTID_INFO_REQ 3
0091 #define PRIV_PKTID_INFO_RESP    4
0092 #define PRIV_PKTID_RESET_REQ    5
0093 #define PRIV_PKTID_SET_DEF_MODE 6
0094 
0095 
0096 #define ETX 0x03
0097 #define DLE 0x10
0098 #define ACK 0x06
0099 #define NAK 0x15
0100 
0101 /* structure used to queue incoming packets */
0102 struct garmin_packet {
0103     struct list_head  list;
0104     int               seq;
0105     /* the real size of the data array, always > 0 */
0106     int               size;
0107     __u8              data[];
0108 };
0109 
0110 /* structure used to keep the current state of the driver */
0111 struct garmin_data {
0112     __u8   state;
0113     __u16  flags;
0114     __u8   mode;
0115     __u8   count;
0116     __u8   pkt_id;
0117     __u32  serial_num;
0118     struct timer_list timer;
0119     struct usb_serial_port *port;
0120     int    seq_counter;
0121     int    insize;
0122     int    outsize;
0123     __u8   inbuffer [GPS_IN_BUFSIZ];  /* tty -> usb */
0124     __u8   outbuffer[GPS_OUT_BUFSIZ]; /* usb -> tty */
0125     __u8   privpkt[4*6];
0126     spinlock_t lock;
0127     struct list_head pktlist;
0128     struct usb_anchor write_urbs;
0129 };
0130 
0131 
0132 #define STATE_NEW            0
0133 #define STATE_INITIAL_DELAY  1
0134 #define STATE_TIMEOUT        2
0135 #define STATE_SESSION_REQ1   3
0136 #define STATE_SESSION_REQ2   4
0137 #define STATE_ACTIVE         5
0138 
0139 #define STATE_RESET      8
0140 #define STATE_DISCONNECTED   9
0141 #define STATE_WAIT_TTY_ACK  10
0142 #define STATE_GSP_WAIT_DATA 11
0143 
0144 #define MODE_NATIVE          0
0145 #define MODE_GARMIN_SERIAL   1
0146 
0147 /* Flags used in garmin_data.flags: */
0148 #define FLAGS_SESSION_REPLY_MASK  0x00C0
0149 #define FLAGS_SESSION_REPLY1_SEEN 0x0080
0150 #define FLAGS_SESSION_REPLY2_SEEN 0x0040
0151 #define FLAGS_BULK_IN_ACTIVE      0x0020
0152 #define FLAGS_BULK_IN_RESTART     0x0010
0153 #define FLAGS_THROTTLED           0x0008
0154 #define APP_REQ_SEEN              0x0004
0155 #define APP_RESP_SEEN             0x0002
0156 #define CLEAR_HALT_REQUIRED       0x0001
0157 
0158 #define FLAGS_QUEUING             0x0100
0159 #define FLAGS_DROP_DATA           0x0800
0160 
0161 #define FLAGS_GSP_SKIP            0x1000
0162 #define FLAGS_GSP_DLESEEN         0x2000
0163 
0164 
0165 
0166 
0167 
0168 
0169 /* function prototypes */
0170 static int gsp_next_packet(struct garmin_data *garmin_data_p);
0171 static int garmin_write_bulk(struct usb_serial_port *port,
0172                  const unsigned char *buf, int count,
0173                  int dismiss_ack);
0174 
0175 /* some special packets to be send or received */
0176 static unsigned char const GARMIN_START_SESSION_REQ[]
0177     = { 0, 0, 0, 0,  5, 0, 0, 0, 0, 0, 0, 0 };
0178 static unsigned char const GARMIN_START_SESSION_REPLY[]
0179     = { 0, 0, 0, 0,  6, 0, 0, 0, 4, 0, 0, 0 };
0180 static unsigned char const GARMIN_BULK_IN_AVAIL_REPLY[]
0181     = { 0, 0, 0, 0,  2, 0, 0, 0, 0, 0, 0, 0 };
0182 static unsigned char const GARMIN_STOP_TRANSFER_REQ[]
0183     = { 20, 0, 0, 0,  10, 0, 0, 0, 2, 0, 0, 0, 0, 0 };
0184 static unsigned char const GARMIN_STOP_TRANSFER_REQ_V2[]
0185     = { 20, 0, 0, 0,  10, 0, 0, 0, 1, 0, 0, 0, 0 };
0186 
0187 /* packets currently unused, left as documentation */
0188 #if 0
0189 static unsigned char const GARMIN_APP_LAYER_REPLY[]
0190     = { 0x14, 0, 0, 0 };
0191 static unsigned char const GARMIN_START_PVT_REQ[]
0192     = { 20, 0, 0, 0,  10, 0, 0, 0, 2, 0, 0, 0, 49, 0 };
0193 static unsigned char const GARMIN_STOP_PVT_REQ[]
0194     = { 20, 0, 0, 0,  10, 0, 0, 0, 2, 0, 0, 0, 50, 0 };
0195 static unsigned char const PRIVATE_REQ[]
0196     =    { 0x4B, 0x6E, 0x10, 0x01,  0xFF, 0, 0, 0, 0xFF, 0, 0, 0 };
0197 #endif
0198 
0199 
0200 static const struct usb_device_id id_table[] = {
0201     /* the same device id seems to be used by all
0202        usb enabled GPS devices */
0203     { USB_DEVICE(GARMIN_VENDOR_ID, 3) },
0204     { }                 /* Terminating entry */
0205 };
0206 MODULE_DEVICE_TABLE(usb, id_table);
0207 
0208 
0209 static inline int getLayerId(const __u8 *usbPacket)
0210 {
0211     return __le32_to_cpup((__le32 *)(usbPacket));
0212 }
0213 
0214 static inline int getPacketId(const __u8 *usbPacket)
0215 {
0216     return __le32_to_cpup((__le32 *)(usbPacket+4));
0217 }
0218 
0219 static inline int getDataLength(const __u8 *usbPacket)
0220 {
0221     return __le32_to_cpup((__le32 *)(usbPacket+8));
0222 }
0223 
0224 
0225 /*
0226  * check if the usb-packet in buf contains an abort-transfer command.
0227  * (if yes, all queued data will be dropped)
0228  */
0229 static inline int isAbortTrfCmnd(const unsigned char *buf)
0230 {
0231     if (memcmp(buf, GARMIN_STOP_TRANSFER_REQ,
0232             sizeof(GARMIN_STOP_TRANSFER_REQ)) == 0 ||
0233         memcmp(buf, GARMIN_STOP_TRANSFER_REQ_V2,
0234             sizeof(GARMIN_STOP_TRANSFER_REQ_V2)) == 0)
0235         return 1;
0236     else
0237         return 0;
0238 }
0239 
0240 
0241 
0242 static void send_to_tty(struct usb_serial_port *port,
0243             char *data, unsigned int actual_length)
0244 {
0245     if (actual_length) {
0246         usb_serial_debug_data(&port->dev, __func__, actual_length, data);
0247         tty_insert_flip_string(&port->port, data, actual_length);
0248         tty_flip_buffer_push(&port->port);
0249     }
0250 }
0251 
0252 
0253 /******************************************************************************
0254  * packet queue handling
0255  ******************************************************************************/
0256 
0257 /*
0258  * queue a received (usb-)packet for later processing
0259  */
0260 static int pkt_add(struct garmin_data *garmin_data_p,
0261            unsigned char *data, unsigned int data_length)
0262 {
0263     int state = 0;
0264     int result = 0;
0265     unsigned long flags;
0266     struct garmin_packet *pkt;
0267 
0268     /* process only packets containing data ... */
0269     if (data_length) {
0270         pkt = kmalloc(sizeof(struct garmin_packet)+data_length,
0271                                 GFP_ATOMIC);
0272         if (!pkt)
0273             return 0;
0274 
0275         pkt->size = data_length;
0276         memcpy(pkt->data, data, data_length);
0277 
0278         spin_lock_irqsave(&garmin_data_p->lock, flags);
0279         garmin_data_p->flags |= FLAGS_QUEUING;
0280         result = list_empty(&garmin_data_p->pktlist);
0281         pkt->seq = garmin_data_p->seq_counter++;
0282         list_add_tail(&pkt->list, &garmin_data_p->pktlist);
0283         state = garmin_data_p->state;
0284         spin_unlock_irqrestore(&garmin_data_p->lock, flags);
0285 
0286         dev_dbg(&garmin_data_p->port->dev,
0287             "%s - added: pkt: %d - %d bytes\n", __func__,
0288             pkt->seq, data_length);
0289 
0290         /* in serial mode, if someone is waiting for data from
0291            the device, convert and send the next packet to tty. */
0292         if (result && (state == STATE_GSP_WAIT_DATA))
0293             gsp_next_packet(garmin_data_p);
0294     }
0295     return result;
0296 }
0297 
0298 
0299 /* get the next pending packet */
0300 static struct garmin_packet *pkt_pop(struct garmin_data *garmin_data_p)
0301 {
0302     unsigned long flags;
0303     struct garmin_packet *result = NULL;
0304 
0305     spin_lock_irqsave(&garmin_data_p->lock, flags);
0306     if (!list_empty(&garmin_data_p->pktlist)) {
0307         result = (struct garmin_packet *)garmin_data_p->pktlist.next;
0308         list_del(&result->list);
0309     }
0310     spin_unlock_irqrestore(&garmin_data_p->lock, flags);
0311     return result;
0312 }
0313 
0314 
0315 /* free up all queued data */
0316 static void pkt_clear(struct garmin_data *garmin_data_p)
0317 {
0318     unsigned long flags;
0319     struct garmin_packet *result = NULL;
0320 
0321     spin_lock_irqsave(&garmin_data_p->lock, flags);
0322     while (!list_empty(&garmin_data_p->pktlist)) {
0323         result = (struct garmin_packet *)garmin_data_p->pktlist.next;
0324         list_del(&result->list);
0325         kfree(result);
0326     }
0327     spin_unlock_irqrestore(&garmin_data_p->lock, flags);
0328 }
0329 
0330 
0331 /******************************************************************************
0332  * garmin serial protocol handling handling
0333  ******************************************************************************/
0334 
0335 /* send an ack packet back to the tty */
0336 static int gsp_send_ack(struct garmin_data *garmin_data_p, __u8 pkt_id)
0337 {
0338     __u8 pkt[10];
0339     __u8 cksum = 0;
0340     __u8 *ptr = pkt;
0341     unsigned  l = 0;
0342 
0343     dev_dbg(&garmin_data_p->port->dev, "%s - pkt-id: 0x%X.\n", __func__,
0344             pkt_id);
0345 
0346     *ptr++ = DLE;
0347     *ptr++ = ACK;
0348     cksum += ACK;
0349 
0350     *ptr++ = 2;
0351     cksum += 2;
0352 
0353     *ptr++ = pkt_id;
0354     cksum += pkt_id;
0355 
0356     if (pkt_id == DLE)
0357         *ptr++ = DLE;
0358 
0359     *ptr++ = 0;
0360     *ptr++ = (-cksum) & 0xFF;
0361     *ptr++ = DLE;
0362     *ptr++ = ETX;
0363 
0364     l = ptr-pkt;
0365 
0366     send_to_tty(garmin_data_p->port, pkt, l);
0367     return 0;
0368 }
0369 
0370 
0371 
0372 /*
0373  * called for a complete packet received from tty layer
0374  *
0375  * the complete packet (pktid ... cksum) is in garmin_data_p->inbuf starting
0376  * at GSP_INITIAL_OFFSET.
0377  *
0378  * count - number of bytes in the input buffer including space reserved for
0379  *         the usb header: GSP_INITIAL_OFFSET + number of bytes in packet
0380  *         (including pkt-id, data-length a. cksum)
0381  */
0382 static int gsp_rec_packet(struct garmin_data *garmin_data_p, int count)
0383 {
0384     struct device *dev = &garmin_data_p->port->dev;
0385     unsigned long flags;
0386     const __u8 *recpkt = garmin_data_p->inbuffer+GSP_INITIAL_OFFSET;
0387     __le32 *usbdata = (__le32 *) garmin_data_p->inbuffer;
0388     int cksum = 0;
0389     int n = 0;
0390     int pktid = recpkt[0];
0391     int size = recpkt[1];
0392 
0393     usb_serial_debug_data(&garmin_data_p->port->dev, __func__,
0394                   count-GSP_INITIAL_OFFSET, recpkt);
0395 
0396     if (size != (count-GSP_INITIAL_OFFSET-3)) {
0397         dev_dbg(dev, "%s - invalid size, expected %d bytes, got %d\n",
0398             __func__, size, (count-GSP_INITIAL_OFFSET-3));
0399         return -EINVPKT;
0400     }
0401 
0402     cksum += *recpkt++;
0403     cksum += *recpkt++;
0404 
0405     /* sanity check, remove after test ... */
0406     if ((__u8 *)&(usbdata[3]) != recpkt) {
0407         dev_dbg(dev, "%s - ptr mismatch %p - %p\n", __func__,
0408             &(usbdata[4]), recpkt);
0409         return -EINVPKT;
0410     }
0411 
0412     while (n < size) {
0413         cksum += *recpkt++;
0414         n++;
0415     }
0416 
0417     if (((cksum + *recpkt) & 0xff) != 0) {
0418         dev_dbg(dev, "%s - invalid checksum, expected %02x, got %02x\n",
0419             __func__, -cksum & 0xff, *recpkt);
0420         return -EINVPKT;
0421     }
0422 
0423     usbdata[0] = __cpu_to_le32(GARMIN_LAYERID_APPL);
0424     usbdata[1] = __cpu_to_le32(pktid);
0425     usbdata[2] = __cpu_to_le32(size);
0426 
0427     garmin_write_bulk(garmin_data_p->port, garmin_data_p->inbuffer,
0428                GARMIN_PKTHDR_LENGTH+size, 0);
0429 
0430     /* if this was an abort-transfer command, flush all
0431        queued data. */
0432     if (isAbortTrfCmnd(garmin_data_p->inbuffer)) {
0433         spin_lock_irqsave(&garmin_data_p->lock, flags);
0434         garmin_data_p->flags |= FLAGS_DROP_DATA;
0435         spin_unlock_irqrestore(&garmin_data_p->lock, flags);
0436         pkt_clear(garmin_data_p);
0437     }
0438 
0439     return count;
0440 }
0441 
0442 
0443 
0444 /*
0445  * Called for data received from tty
0446  *
0447  * buf contains the data read, it may span more than one packet or even
0448  * incomplete packets
0449  *
0450  * input record should be a serial-record, but it may not be complete.
0451  * Copy it into our local buffer, until an etx is seen (or an error
0452  * occurs).
0453  * Once the record is complete, convert into a usb packet and send it
0454  * to the bulk pipe, send an ack back to the tty.
0455  *
0456  * If the input is an ack, just send the last queued packet to the
0457  * tty layer.
0458  *
0459  * if the input is an abort command, drop all queued data.
0460  */
0461 
0462 static int gsp_receive(struct garmin_data *garmin_data_p,
0463                const unsigned char *buf, int count)
0464 {
0465     struct device *dev = &garmin_data_p->port->dev;
0466     unsigned long flags;
0467     int offs = 0;
0468     int ack_or_nak_seen = 0;
0469     __u8 *dest;
0470     int size;
0471     /* dleSeen: set if last byte read was a DLE */
0472     int dleSeen;
0473     /* skip: if set, skip incoming data until possible start of
0474      *       new packet
0475      */
0476     int skip;
0477     __u8 data;
0478 
0479     spin_lock_irqsave(&garmin_data_p->lock, flags);
0480     dest = garmin_data_p->inbuffer;
0481     size = garmin_data_p->insize;
0482     dleSeen = garmin_data_p->flags & FLAGS_GSP_DLESEEN;
0483     skip = garmin_data_p->flags & FLAGS_GSP_SKIP;
0484     spin_unlock_irqrestore(&garmin_data_p->lock, flags);
0485 
0486     /* dev_dbg(dev, "%s - dle=%d skip=%d size=%d count=%d\n",
0487         __func__, dleSeen, skip, size, count); */
0488 
0489     if (size == 0)
0490         size = GSP_INITIAL_OFFSET;
0491 
0492     while (offs < count) {
0493 
0494         data = *(buf+offs);
0495         offs++;
0496 
0497         if (data == DLE) {
0498             if (skip) { /* start of a new pkt */
0499                 skip = 0;
0500                 size = GSP_INITIAL_OFFSET;
0501                 dleSeen = 1;
0502             } else if (dleSeen) {
0503                 dest[size++] = data;
0504                 dleSeen = 0;
0505             } else {
0506                 dleSeen = 1;
0507             }
0508         } else if (data == ETX) {
0509             if (dleSeen) {
0510                 /* packet complete */
0511 
0512                 data = dest[GSP_INITIAL_OFFSET];
0513 
0514                 if (data == ACK) {
0515                     ack_or_nak_seen = ACK;
0516                     dev_dbg(dev, "ACK packet complete.\n");
0517                 } else if (data == NAK) {
0518                     ack_or_nak_seen = NAK;
0519                     dev_dbg(dev, "NAK packet complete.\n");
0520                 } else {
0521                     dev_dbg(dev, "packet complete - id=0x%X.\n",
0522                             data);
0523                     gsp_rec_packet(garmin_data_p, size);
0524                 }
0525 
0526                 skip = 1;
0527                 size = GSP_INITIAL_OFFSET;
0528                 dleSeen = 0;
0529             } else {
0530                 dest[size++] = data;
0531             }
0532         } else if (!skip) {
0533 
0534             if (dleSeen) {
0535                 size = GSP_INITIAL_OFFSET;
0536                 dleSeen = 0;
0537             }
0538 
0539             dest[size++] = data;
0540         }
0541 
0542         if (size >= GPS_IN_BUFSIZ) {
0543             dev_dbg(dev, "%s - packet too large.\n", __func__);
0544             skip = 1;
0545             size = GSP_INITIAL_OFFSET;
0546             dleSeen = 0;
0547         }
0548     }
0549 
0550     spin_lock_irqsave(&garmin_data_p->lock, flags);
0551 
0552     garmin_data_p->insize = size;
0553 
0554     /* copy flags back to structure */
0555     if (skip)
0556         garmin_data_p->flags |= FLAGS_GSP_SKIP;
0557     else
0558         garmin_data_p->flags &= ~FLAGS_GSP_SKIP;
0559 
0560     if (dleSeen)
0561         garmin_data_p->flags |= FLAGS_GSP_DLESEEN;
0562     else
0563         garmin_data_p->flags &= ~FLAGS_GSP_DLESEEN;
0564 
0565     spin_unlock_irqrestore(&garmin_data_p->lock, flags);
0566 
0567     if (ack_or_nak_seen) {
0568         if (gsp_next_packet(garmin_data_p) > 0)
0569             garmin_data_p->state = STATE_ACTIVE;
0570         else
0571             garmin_data_p->state = STATE_GSP_WAIT_DATA;
0572     }
0573     return count;
0574 }
0575 
0576 
0577 
0578 /*
0579  * Sends a usb packet to the tty
0580  *
0581  * Assumes, that all packages and at an usb-packet boundary.
0582  *
0583  * return <0 on error, 0 if packet is incomplete or > 0 if packet was sent
0584  */
0585 static int gsp_send(struct garmin_data *garmin_data_p,
0586             const unsigned char *buf, int count)
0587 {
0588     struct device *dev = &garmin_data_p->port->dev;
0589     const unsigned char *src;
0590     unsigned char *dst;
0591     int pktid = 0;
0592     int datalen = 0;
0593     int cksum = 0;
0594     int i = 0;
0595     int k;
0596 
0597     dev_dbg(dev, "%s - state %d - %d bytes.\n", __func__,
0598         garmin_data_p->state, count);
0599 
0600     k = garmin_data_p->outsize;
0601     if ((k+count) > GPS_OUT_BUFSIZ) {
0602         dev_dbg(dev, "packet too large\n");
0603         garmin_data_p->outsize = 0;
0604         return -4;
0605     }
0606 
0607     memcpy(garmin_data_p->outbuffer+k, buf, count);
0608     k += count;
0609     garmin_data_p->outsize = k;
0610 
0611     if (k >= GARMIN_PKTHDR_LENGTH) {
0612         pktid  = getPacketId(garmin_data_p->outbuffer);
0613         datalen = getDataLength(garmin_data_p->outbuffer);
0614         i = GARMIN_PKTHDR_LENGTH + datalen;
0615         if (k < i)
0616             return 0;
0617     } else {
0618         return 0;
0619     }
0620 
0621     dev_dbg(dev, "%s - %d bytes in buffer, %d bytes in pkt.\n", __func__, k, i);
0622 
0623     /* garmin_data_p->outbuffer now contains a complete packet */
0624 
0625     usb_serial_debug_data(&garmin_data_p->port->dev, __func__, k,
0626                   garmin_data_p->outbuffer);
0627 
0628     garmin_data_p->outsize = 0;
0629 
0630     if (getLayerId(garmin_data_p->outbuffer) != GARMIN_LAYERID_APPL) {
0631         dev_dbg(dev, "not an application packet (%d)\n",
0632                 getLayerId(garmin_data_p->outbuffer));
0633         return -1;
0634     }
0635 
0636     if (pktid > 255) {
0637         dev_dbg(dev, "packet-id %d too large\n", pktid);
0638         return -2;
0639     }
0640 
0641     if (datalen > 255) {
0642         dev_dbg(dev, "packet-size %d too large\n", datalen);
0643         return -3;
0644     }
0645 
0646     /* the serial protocol should be able to handle this packet */
0647 
0648     k = 0;
0649     src = garmin_data_p->outbuffer+GARMIN_PKTHDR_LENGTH;
0650     for (i = 0; i < datalen; i++) {
0651         if (*src++ == DLE)
0652             k++;
0653     }
0654 
0655     src = garmin_data_p->outbuffer+GARMIN_PKTHDR_LENGTH;
0656     if (k > (GARMIN_PKTHDR_LENGTH-2)) {
0657         /* can't add stuffing DLEs in place, move data to end
0658            of buffer ... */
0659         dst = garmin_data_p->outbuffer+GPS_OUT_BUFSIZ-datalen;
0660         memcpy(dst, src, datalen);
0661         src = dst;
0662     }
0663 
0664     dst = garmin_data_p->outbuffer;
0665 
0666     *dst++ = DLE;
0667     *dst++ = pktid;
0668     cksum += pktid;
0669     *dst++ = datalen;
0670     cksum += datalen;
0671     if (datalen == DLE)
0672         *dst++ = DLE;
0673 
0674     for (i = 0; i < datalen; i++) {
0675         __u8 c = *src++;
0676         *dst++ = c;
0677         cksum += c;
0678         if (c == DLE)
0679             *dst++ = DLE;
0680     }
0681 
0682     cksum = -cksum & 0xFF;
0683     *dst++ = cksum;
0684     if (cksum == DLE)
0685         *dst++ = DLE;
0686     *dst++ = DLE;
0687     *dst++ = ETX;
0688 
0689     i = dst-garmin_data_p->outbuffer;
0690 
0691     send_to_tty(garmin_data_p->port, garmin_data_p->outbuffer, i);
0692 
0693     garmin_data_p->pkt_id = pktid;
0694     garmin_data_p->state  = STATE_WAIT_TTY_ACK;
0695 
0696     return i;
0697 }
0698 
0699 
0700 /*
0701  * Process the next pending data packet - if there is one
0702  */
0703 static int gsp_next_packet(struct garmin_data *garmin_data_p)
0704 {
0705     int result = 0;
0706     struct garmin_packet *pkt = NULL;
0707 
0708     while ((pkt = pkt_pop(garmin_data_p)) != NULL) {
0709         dev_dbg(&garmin_data_p->port->dev, "%s - next pkt: %d\n", __func__, pkt->seq);
0710         result = gsp_send(garmin_data_p, pkt->data, pkt->size);
0711         if (result > 0) {
0712             kfree(pkt);
0713             return result;
0714         }
0715         kfree(pkt);
0716     }
0717     return result;
0718 }
0719 
0720 
0721 
0722 /******************************************************************************
0723  * garmin native mode
0724  ******************************************************************************/
0725 
0726 
0727 /*
0728  * Called for data received from tty
0729  *
0730  * The input data is expected to be in garmin usb-packet format.
0731  *
0732  * buf contains the data read, it may span more than one packet
0733  * or even incomplete packets
0734  */
0735 static int nat_receive(struct garmin_data *garmin_data_p,
0736                const unsigned char *buf, int count)
0737 {
0738     unsigned long flags;
0739     __u8 *dest;
0740     int offs = 0;
0741     int result = count;
0742     int len;
0743 
0744     while (offs < count) {
0745         /* if buffer contains header, copy rest of data */
0746         if (garmin_data_p->insize >= GARMIN_PKTHDR_LENGTH)
0747             len = GARMIN_PKTHDR_LENGTH
0748                   +getDataLength(garmin_data_p->inbuffer);
0749         else
0750             len = GARMIN_PKTHDR_LENGTH;
0751 
0752         if (len >= GPS_IN_BUFSIZ) {
0753             /* seems to be an invalid packet, ignore rest
0754                of input */
0755             dev_dbg(&garmin_data_p->port->dev,
0756                 "%s - packet size too large: %d\n",
0757                 __func__, len);
0758             garmin_data_p->insize = 0;
0759             count = 0;
0760             result = -EINVPKT;
0761         } else {
0762             len -= garmin_data_p->insize;
0763             if (len > (count-offs))
0764                 len = (count-offs);
0765             if (len > 0) {
0766                 dest = garmin_data_p->inbuffer
0767                         + garmin_data_p->insize;
0768                 memcpy(dest, buf+offs, len);
0769                 garmin_data_p->insize += len;
0770                 offs += len;
0771             }
0772         }
0773 
0774         /* do we have a complete packet ? */
0775         if (garmin_data_p->insize >= GARMIN_PKTHDR_LENGTH) {
0776             len = GARMIN_PKTHDR_LENGTH+
0777                getDataLength(garmin_data_p->inbuffer);
0778             if (garmin_data_p->insize >= len) {
0779                 garmin_write_bulk(garmin_data_p->port,
0780                            garmin_data_p->inbuffer,
0781                            len, 0);
0782                 garmin_data_p->insize = 0;
0783 
0784                 /* if this was an abort-transfer command,
0785                    flush all queued data. */
0786                 if (isAbortTrfCmnd(garmin_data_p->inbuffer)) {
0787                     spin_lock_irqsave(&garmin_data_p->lock,
0788                                     flags);
0789                     garmin_data_p->flags |= FLAGS_DROP_DATA;
0790                     spin_unlock_irqrestore(
0791                         &garmin_data_p->lock, flags);
0792                     pkt_clear(garmin_data_p);
0793                 }
0794             }
0795         }
0796     }
0797     return result;
0798 }
0799 
0800 
0801 /******************************************************************************
0802  * private packets
0803  ******************************************************************************/
0804 
0805 static void priv_status_resp(struct usb_serial_port *port)
0806 {
0807     struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
0808     __le32 *pkt = (__le32 *)garmin_data_p->privpkt;
0809 
0810     pkt[0] = __cpu_to_le32(GARMIN_LAYERID_PRIVATE);
0811     pkt[1] = __cpu_to_le32(PRIV_PKTID_INFO_RESP);
0812     pkt[2] = __cpu_to_le32(12);
0813     pkt[3] = __cpu_to_le32(VERSION_MAJOR << 16 | VERSION_MINOR);
0814     pkt[4] = __cpu_to_le32(garmin_data_p->mode);
0815     pkt[5] = __cpu_to_le32(garmin_data_p->serial_num);
0816 
0817     send_to_tty(port, (__u8 *)pkt, 6 * 4);
0818 }
0819 
0820 
0821 /******************************************************************************
0822  * Garmin specific driver functions
0823  ******************************************************************************/
0824 
0825 static int process_resetdev_request(struct usb_serial_port *port)
0826 {
0827     unsigned long flags;
0828     int status;
0829     struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
0830 
0831     spin_lock_irqsave(&garmin_data_p->lock, flags);
0832     garmin_data_p->flags &= ~(CLEAR_HALT_REQUIRED);
0833     garmin_data_p->state = STATE_RESET;
0834     garmin_data_p->serial_num = 0;
0835     spin_unlock_irqrestore(&garmin_data_p->lock, flags);
0836 
0837     usb_kill_urb(port->interrupt_in_urb);
0838     dev_dbg(&port->dev, "%s - usb_reset_device\n", __func__);
0839     status = usb_reset_device(port->serial->dev);
0840     if (status)
0841         dev_dbg(&port->dev, "%s - usb_reset_device failed: %d\n",
0842             __func__, status);
0843     return status;
0844 }
0845 
0846 
0847 
0848 /*
0849  * clear all cached data
0850  */
0851 static int garmin_clear(struct garmin_data *garmin_data_p)
0852 {
0853     unsigned long flags;
0854 
0855     /* flush all queued data */
0856     pkt_clear(garmin_data_p);
0857 
0858     spin_lock_irqsave(&garmin_data_p->lock, flags);
0859     garmin_data_p->insize = 0;
0860     garmin_data_p->outsize = 0;
0861     spin_unlock_irqrestore(&garmin_data_p->lock, flags);
0862 
0863     return 0;
0864 }
0865 
0866 
0867 static int garmin_init_session(struct usb_serial_port *port)
0868 {
0869     struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
0870     int status;
0871     int i;
0872 
0873     usb_kill_urb(port->interrupt_in_urb);
0874 
0875     status = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
0876     if (status) {
0877         dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
0878                 status);
0879         return status;
0880     }
0881 
0882     /*
0883      * using the initialization method from gpsbabel. See comments in
0884      * gpsbabel/jeeps/gpslibusb.c gusb_reset_toggles()
0885      */
0886     dev_dbg(&port->dev, "%s - starting session ...\n", __func__);
0887     garmin_data_p->state = STATE_ACTIVE;
0888 
0889     for (i = 0; i < 3; i++) {
0890         status = garmin_write_bulk(port, GARMIN_START_SESSION_REQ,
0891                 sizeof(GARMIN_START_SESSION_REQ), 0);
0892         if (status < 0)
0893             goto err_kill_urbs;
0894     }
0895 
0896     return 0;
0897 
0898 err_kill_urbs:
0899     usb_kill_anchored_urbs(&garmin_data_p->write_urbs);
0900     usb_kill_urb(port->interrupt_in_urb);
0901 
0902     return status;
0903 }
0904 
0905 
0906 
0907 static int garmin_open(struct tty_struct *tty, struct usb_serial_port *port)
0908 {
0909     unsigned long flags;
0910     int status = 0;
0911     struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
0912 
0913     spin_lock_irqsave(&garmin_data_p->lock, flags);
0914     garmin_data_p->mode  = initial_mode;
0915     garmin_data_p->count = 0;
0916     garmin_data_p->flags &= FLAGS_SESSION_REPLY1_SEEN;
0917     spin_unlock_irqrestore(&garmin_data_p->lock, flags);
0918 
0919     /* shutdown any bulk reads that might be going on */
0920     usb_kill_urb(port->read_urb);
0921 
0922     if (garmin_data_p->state == STATE_RESET)
0923         status = garmin_init_session(port);
0924 
0925     garmin_data_p->state = STATE_ACTIVE;
0926     return status;
0927 }
0928 
0929 
0930 static void garmin_close(struct usb_serial_port *port)
0931 {
0932     struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
0933 
0934     dev_dbg(&port->dev, "%s - mode=%d state=%d flags=0x%X\n",
0935         __func__, garmin_data_p->mode, garmin_data_p->state,
0936         garmin_data_p->flags);
0937 
0938     garmin_clear(garmin_data_p);
0939 
0940     /* shutdown our urbs */
0941     usb_kill_urb(port->read_urb);
0942     usb_kill_anchored_urbs(&garmin_data_p->write_urbs);
0943 
0944     /* keep reset state so we know that we must start a new session */
0945     if (garmin_data_p->state != STATE_RESET)
0946         garmin_data_p->state = STATE_DISCONNECTED;
0947 }
0948 
0949 
0950 static void garmin_write_bulk_callback(struct urb *urb)
0951 {
0952     struct usb_serial_port *port = urb->context;
0953 
0954     if (port) {
0955         struct garmin_data *garmin_data_p =
0956                     usb_get_serial_port_data(port);
0957 
0958         if (getLayerId(urb->transfer_buffer) == GARMIN_LAYERID_APPL) {
0959 
0960             if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
0961                 gsp_send_ack(garmin_data_p,
0962                     ((__u8 *)urb->transfer_buffer)[4]);
0963             }
0964         }
0965         usb_serial_port_softint(port);
0966     }
0967 
0968     /* Ignore errors that resulted from garmin_write_bulk with
0969        dismiss_ack = 1 */
0970 
0971     /* free up the transfer buffer, as usb_free_urb() does not do this */
0972     kfree(urb->transfer_buffer);
0973 }
0974 
0975 
0976 static int garmin_write_bulk(struct usb_serial_port *port,
0977                   const unsigned char *buf, int count,
0978                   int dismiss_ack)
0979 {
0980     unsigned long flags;
0981     struct usb_serial *serial = port->serial;
0982     struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
0983     struct urb *urb;
0984     unsigned char *buffer;
0985     int status;
0986 
0987     spin_lock_irqsave(&garmin_data_p->lock, flags);
0988     garmin_data_p->flags &= ~FLAGS_DROP_DATA;
0989     spin_unlock_irqrestore(&garmin_data_p->lock, flags);
0990 
0991     buffer = kmemdup(buf, count, GFP_ATOMIC);
0992     if (!buffer)
0993         return -ENOMEM;
0994 
0995     urb = usb_alloc_urb(0, GFP_ATOMIC);
0996     if (!urb) {
0997         kfree(buffer);
0998         return -ENOMEM;
0999     }
1000 
1001     usb_serial_debug_data(&port->dev, __func__, count, buffer);
1002 
1003     usb_fill_bulk_urb(urb, serial->dev,
1004                 usb_sndbulkpipe(serial->dev,
1005                     port->bulk_out_endpointAddress),
1006                 buffer, count,
1007                 garmin_write_bulk_callback,
1008                 dismiss_ack ? NULL : port);
1009     urb->transfer_flags |= URB_ZERO_PACKET;
1010 
1011     if (getLayerId(buffer) == GARMIN_LAYERID_APPL) {
1012 
1013         spin_lock_irqsave(&garmin_data_p->lock, flags);
1014         garmin_data_p->flags |= APP_REQ_SEEN;
1015         spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1016 
1017         if (garmin_data_p->mode == MODE_GARMIN_SERIAL)  {
1018             pkt_clear(garmin_data_p);
1019             garmin_data_p->state = STATE_GSP_WAIT_DATA;
1020         }
1021     }
1022 
1023     /* send it down the pipe */
1024     usb_anchor_urb(urb, &garmin_data_p->write_urbs);
1025     status = usb_submit_urb(urb, GFP_ATOMIC);
1026     if (status) {
1027         dev_err(&port->dev,
1028            "%s - usb_submit_urb(write bulk) failed with status = %d\n",
1029                 __func__, status);
1030         count = status;
1031         usb_unanchor_urb(urb);
1032         kfree(buffer);
1033     }
1034 
1035     /* we are done with this urb, so let the host driver
1036      * really free it when it is finished with it */
1037     usb_free_urb(urb);
1038 
1039     return count;
1040 }
1041 
1042 static int garmin_write(struct tty_struct *tty, struct usb_serial_port *port,
1043                      const unsigned char *buf, int count)
1044 {
1045     struct device *dev = &port->dev;
1046     int pktid, pktsiz, len;
1047     struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1048     __le32 *privpkt = (__le32 *)garmin_data_p->privpkt;
1049 
1050     usb_serial_debug_data(dev, __func__, count, buf);
1051 
1052     if (garmin_data_p->state == STATE_RESET)
1053         return -EIO;
1054 
1055     /* check for our private packets */
1056     if (count >= GARMIN_PKTHDR_LENGTH) {
1057         len = PRIVPKTSIZ;
1058         if (count < len)
1059             len = count;
1060 
1061         memcpy(garmin_data_p->privpkt, buf, len);
1062 
1063         pktsiz = getDataLength(garmin_data_p->privpkt);
1064         pktid  = getPacketId(garmin_data_p->privpkt);
1065 
1066         if (count == (GARMIN_PKTHDR_LENGTH + pktsiz) &&
1067                 getLayerId(garmin_data_p->privpkt) ==
1068                         GARMIN_LAYERID_PRIVATE) {
1069 
1070             dev_dbg(dev, "%s - processing private request %d\n",
1071                 __func__, pktid);
1072 
1073             /* drop all unfinished transfers */
1074             garmin_clear(garmin_data_p);
1075 
1076             switch (pktid) {
1077             case PRIV_PKTID_SET_MODE:
1078                 if (pktsiz != 4)
1079                     return -EINVPKT;
1080                 garmin_data_p->mode = __le32_to_cpu(privpkt[3]);
1081                 dev_dbg(dev, "%s - mode set to %d\n",
1082                     __func__, garmin_data_p->mode);
1083                 break;
1084 
1085             case PRIV_PKTID_INFO_REQ:
1086                 priv_status_resp(port);
1087                 break;
1088 
1089             case PRIV_PKTID_RESET_REQ:
1090                 process_resetdev_request(port);
1091                 break;
1092 
1093             case PRIV_PKTID_SET_DEF_MODE:
1094                 if (pktsiz != 4)
1095                     return -EINVPKT;
1096                 initial_mode = __le32_to_cpu(privpkt[3]);
1097                 dev_dbg(dev, "%s - initial_mode set to %d\n",
1098                     __func__,
1099                     garmin_data_p->mode);
1100                 break;
1101             }
1102             return count;
1103         }
1104     }
1105 
1106     if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
1107         return gsp_receive(garmin_data_p, buf, count);
1108     } else {    /* MODE_NATIVE */
1109         return nat_receive(garmin_data_p, buf, count);
1110     }
1111 }
1112 
1113 
1114 static unsigned int garmin_write_room(struct tty_struct *tty)
1115 {
1116     struct usb_serial_port *port = tty->driver_data;
1117     /*
1118      * Report back the bytes currently available in the output buffer.
1119      */
1120     struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1121     return GPS_OUT_BUFSIZ-garmin_data_p->outsize;
1122 }
1123 
1124 
1125 static void garmin_read_process(struct garmin_data *garmin_data_p,
1126                  unsigned char *data, unsigned data_length,
1127                  int bulk_data)
1128 {
1129     unsigned long flags;
1130 
1131     if (garmin_data_p->flags & FLAGS_DROP_DATA) {
1132         /* abort-transfer cmd is active */
1133         dev_dbg(&garmin_data_p->port->dev, "%s - pkt dropped\n", __func__);
1134     } else if (garmin_data_p->state != STATE_DISCONNECTED &&
1135         garmin_data_p->state != STATE_RESET) {
1136 
1137         /* if throttling is active or postprecessing is required
1138            put the received data in the input queue, otherwise
1139            send it directly to the tty port */
1140         if (garmin_data_p->flags & FLAGS_QUEUING) {
1141             pkt_add(garmin_data_p, data, data_length);
1142         } else if (bulk_data || (data_length >= sizeof(u32) &&
1143                 getLayerId(data) == GARMIN_LAYERID_APPL)) {
1144 
1145             spin_lock_irqsave(&garmin_data_p->lock, flags);
1146             garmin_data_p->flags |= APP_RESP_SEEN;
1147             spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1148 
1149             if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
1150                 pkt_add(garmin_data_p, data, data_length);
1151             } else {
1152                 send_to_tty(garmin_data_p->port, data,
1153                         data_length);
1154             }
1155         }
1156         /* ignore system layer packets ... */
1157     }
1158 }
1159 
1160 
1161 static void garmin_read_bulk_callback(struct urb *urb)
1162 {
1163     unsigned long flags;
1164     struct usb_serial_port *port = urb->context;
1165     struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1166     unsigned char *data = urb->transfer_buffer;
1167     int status = urb->status;
1168     int retval;
1169 
1170     if (status) {
1171         dev_dbg(&urb->dev->dev, "%s - nonzero read bulk status received: %d\n",
1172             __func__, status);
1173         return;
1174     }
1175 
1176     usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
1177 
1178     garmin_read_process(garmin_data_p, data, urb->actual_length, 1);
1179 
1180     if (urb->actual_length == 0 &&
1181             (garmin_data_p->flags & FLAGS_BULK_IN_RESTART) != 0) {
1182         spin_lock_irqsave(&garmin_data_p->lock, flags);
1183         garmin_data_p->flags &= ~FLAGS_BULK_IN_RESTART;
1184         spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1185         retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
1186         if (retval)
1187             dev_err(&port->dev,
1188                 "%s - failed resubmitting read urb, error %d\n",
1189                 __func__, retval);
1190     } else if (urb->actual_length > 0) {
1191         /* Continue trying to read until nothing more is received  */
1192         if ((garmin_data_p->flags & FLAGS_THROTTLED) == 0) {
1193             retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
1194             if (retval)
1195                 dev_err(&port->dev,
1196                     "%s - failed resubmitting read urb, error %d\n",
1197                     __func__, retval);
1198         }
1199     } else {
1200         dev_dbg(&port->dev, "%s - end of bulk data\n", __func__);
1201         spin_lock_irqsave(&garmin_data_p->lock, flags);
1202         garmin_data_p->flags &= ~FLAGS_BULK_IN_ACTIVE;
1203         spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1204     }
1205 }
1206 
1207 
1208 static void garmin_read_int_callback(struct urb *urb)
1209 {
1210     unsigned long flags;
1211     int retval;
1212     struct usb_serial_port *port = urb->context;
1213     struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1214     unsigned char *data = urb->transfer_buffer;
1215     int status = urb->status;
1216 
1217     switch (status) {
1218     case 0:
1219         /* success */
1220         break;
1221     case -ECONNRESET:
1222     case -ENOENT:
1223     case -ESHUTDOWN:
1224         /* this urb is terminated, clean up */
1225         dev_dbg(&urb->dev->dev, "%s - urb shutting down with status: %d\n",
1226             __func__, status);
1227         return;
1228     default:
1229         dev_dbg(&urb->dev->dev, "%s - nonzero urb status received: %d\n",
1230             __func__, status);
1231         return;
1232     }
1233 
1234     usb_serial_debug_data(&port->dev, __func__, urb->actual_length,
1235                   urb->transfer_buffer);
1236 
1237     if (urb->actual_length == sizeof(GARMIN_BULK_IN_AVAIL_REPLY) &&
1238         memcmp(data, GARMIN_BULK_IN_AVAIL_REPLY,
1239                 sizeof(GARMIN_BULK_IN_AVAIL_REPLY)) == 0) {
1240 
1241         dev_dbg(&port->dev, "%s - bulk data available.\n", __func__);
1242 
1243         if ((garmin_data_p->flags & FLAGS_BULK_IN_ACTIVE) == 0) {
1244 
1245             /* bulk data available */
1246             retval = usb_submit_urb(port->read_urb, GFP_ATOMIC);
1247             if (retval) {
1248                 dev_err(&port->dev,
1249                  "%s - failed submitting read urb, error %d\n",
1250                             __func__, retval);
1251             } else {
1252                 spin_lock_irqsave(&garmin_data_p->lock, flags);
1253                 garmin_data_p->flags |= FLAGS_BULK_IN_ACTIVE;
1254                 spin_unlock_irqrestore(&garmin_data_p->lock,
1255                                     flags);
1256             }
1257         } else {
1258             /* bulk-in transfer still active */
1259             spin_lock_irqsave(&garmin_data_p->lock, flags);
1260             garmin_data_p->flags |= FLAGS_BULK_IN_RESTART;
1261             spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1262         }
1263 
1264     } else if (urb->actual_length == (4+sizeof(GARMIN_START_SESSION_REPLY))
1265              && memcmp(data, GARMIN_START_SESSION_REPLY,
1266                  sizeof(GARMIN_START_SESSION_REPLY)) == 0) {
1267 
1268         spin_lock_irqsave(&garmin_data_p->lock, flags);
1269         garmin_data_p->flags |= FLAGS_SESSION_REPLY1_SEEN;
1270         spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1271 
1272         /* save the serial number */
1273         garmin_data_p->serial_num = __le32_to_cpup(
1274                     (__le32 *)(data+GARMIN_PKTHDR_LENGTH));
1275 
1276         dev_dbg(&port->dev, "%s - start-of-session reply seen - serial %u.\n",
1277             __func__, garmin_data_p->serial_num);
1278     }
1279 
1280     garmin_read_process(garmin_data_p, data, urb->actual_length, 0);
1281 
1282     retval = usb_submit_urb(urb, GFP_ATOMIC);
1283     if (retval)
1284         dev_err(&urb->dev->dev,
1285             "%s - Error %d submitting interrupt urb\n",
1286             __func__, retval);
1287 }
1288 
1289 
1290 /*
1291  * Sends the next queued packt to the tty port (garmin native mode only)
1292  * and then sets a timer to call itself again until all queued data
1293  * is sent.
1294  */
1295 static int garmin_flush_queue(struct garmin_data *garmin_data_p)
1296 {
1297     unsigned long flags;
1298     struct garmin_packet *pkt;
1299 
1300     if ((garmin_data_p->flags & FLAGS_THROTTLED) == 0) {
1301         pkt = pkt_pop(garmin_data_p);
1302         if (pkt != NULL) {
1303             send_to_tty(garmin_data_p->port, pkt->data, pkt->size);
1304             kfree(pkt);
1305             mod_timer(&garmin_data_p->timer, (1)+jiffies);
1306 
1307         } else {
1308             spin_lock_irqsave(&garmin_data_p->lock, flags);
1309             garmin_data_p->flags &= ~FLAGS_QUEUING;
1310             spin_unlock_irqrestore(&garmin_data_p->lock, flags);
1311         }
1312     }
1313     return 0;
1314 }
1315 
1316 
1317 static void garmin_throttle(struct tty_struct *tty)
1318 {
1319     struct usb_serial_port *port = tty->driver_data;
1320     struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1321 
1322     /* set flag, data received will be put into a queue
1323        for later processing */
1324     spin_lock_irq(&garmin_data_p->lock);
1325     garmin_data_p->flags |= FLAGS_QUEUING|FLAGS_THROTTLED;
1326     spin_unlock_irq(&garmin_data_p->lock);
1327 }
1328 
1329 
1330 static void garmin_unthrottle(struct tty_struct *tty)
1331 {
1332     struct usb_serial_port *port = tty->driver_data;
1333     struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1334     int status;
1335 
1336     spin_lock_irq(&garmin_data_p->lock);
1337     garmin_data_p->flags &= ~FLAGS_THROTTLED;
1338     spin_unlock_irq(&garmin_data_p->lock);
1339 
1340     /* in native mode send queued data to tty, in
1341        serial mode nothing needs to be done here */
1342     if (garmin_data_p->mode == MODE_NATIVE)
1343         garmin_flush_queue(garmin_data_p);
1344 
1345     if ((garmin_data_p->flags & FLAGS_BULK_IN_ACTIVE) != 0) {
1346         status = usb_submit_urb(port->read_urb, GFP_KERNEL);
1347         if (status)
1348             dev_err(&port->dev,
1349                 "%s - failed resubmitting read urb, error %d\n",
1350                 __func__, status);
1351     }
1352 }
1353 
1354 /*
1355  * The timer is currently only used to send queued packets to
1356  * the tty in cases where the protocol provides no own handshaking
1357  * to initiate the transfer.
1358  */
1359 static void timeout_handler(struct timer_list *t)
1360 {
1361     struct garmin_data *garmin_data_p = from_timer(garmin_data_p, t, timer);
1362 
1363     /* send the next queued packet to the tty port */
1364     if (garmin_data_p->mode == MODE_NATIVE)
1365         if (garmin_data_p->flags & FLAGS_QUEUING)
1366             garmin_flush_queue(garmin_data_p);
1367 }
1368 
1369 
1370 
1371 static int garmin_port_probe(struct usb_serial_port *port)
1372 {
1373     int status;
1374     struct garmin_data *garmin_data_p;
1375 
1376     garmin_data_p = kzalloc(sizeof(struct garmin_data), GFP_KERNEL);
1377     if (!garmin_data_p)
1378         return -ENOMEM;
1379 
1380     timer_setup(&garmin_data_p->timer, timeout_handler, 0);
1381     spin_lock_init(&garmin_data_p->lock);
1382     INIT_LIST_HEAD(&garmin_data_p->pktlist);
1383     garmin_data_p->port = port;
1384     garmin_data_p->state = 0;
1385     garmin_data_p->flags = 0;
1386     garmin_data_p->count = 0;
1387     init_usb_anchor(&garmin_data_p->write_urbs);
1388     usb_set_serial_port_data(port, garmin_data_p);
1389 
1390     status = garmin_init_session(port);
1391     if (status)
1392         goto err_free;
1393 
1394     return 0;
1395 err_free:
1396     kfree(garmin_data_p);
1397 
1398     return status;
1399 }
1400 
1401 
1402 static void garmin_port_remove(struct usb_serial_port *port)
1403 {
1404     struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
1405 
1406     usb_kill_anchored_urbs(&garmin_data_p->write_urbs);
1407     usb_kill_urb(port->interrupt_in_urb);
1408     del_timer_sync(&garmin_data_p->timer);
1409     kfree(garmin_data_p);
1410 }
1411 
1412 
1413 /* All of the device info needed */
1414 static 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 
1435 static struct usb_serial_driver * const serial_drivers[] = {
1436     &garmin_device, NULL
1437 };
1438 
1439 module_usb_serial_driver(serial_drivers, id_table);
1440 
1441 MODULE_AUTHOR(DRIVER_AUTHOR);
1442 MODULE_DESCRIPTION(DRIVER_DESC);
1443 MODULE_LICENSE("GPL");
1444 
1445 module_param(initial_mode, int, 0444);
1446 MODULE_PARM_DESC(initial_mode, "Initial mode");
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