path: root/drivers/usb/serial/garmin_gps.c

/*
 * Garmin GPS driver
 *
 * Copyright (C) 2006-2011 Hermann Kneissel herkne@gmx.de
 *
 * The latest version of the driver can be found at
 * http://sourceforge.net/projects/garmin-gps/
 *
 * This driver has been derived from v2.1 of the visor driver.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111 USA
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/atomic.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>

/* the mode to be set when the port ist opened */
static int initial_mode = 1;

/* debug flag */
static bool debug;

#define GARMIN_VENDOR_ID             0x091E

/*
 * Version Information
 */

#define VERSION_MAJOR	0
#define VERSION_MINOR	36

#define _STR(s) #s
#define _DRIVER_VERSION(a, b) "v" _STR(a) "." _STR(b)
#define DRIVER_VERSION _DRIVER_VERSION(VERSION_MAJOR, VERSION_MINOR)
#define DRIVER_AUTHOR "hermann kneissel"
#define DRIVER_DESC "garmin gps driver"

/* error codes returned by the driver */
#define EINVPKT	1000	/* invalid packet structure */


/* size of the header of a packet using the usb protocol */
#define GARMIN_PKTHDR_LENGTH	12

/* max. possible size of a packet using the serial protocol */
#define MAX_SERIAL_PKT_SIZ (3 + 255 + 3)

/*  max. possible size of a packet with worst case stuffing */
#define MAX_SERIAL_PKT_SIZ_STUFFED (MAX_SERIAL_PKT_SIZ + 256)

/* size of a buffer able to hold a complete (no stuffing) packet
 * (the document protocol does not contain packets with a larger
 *  size, but in theory a packet may be 64k+12 bytes - if in
 *  later protocol versions larger packet sizes occur, this value
 *  should be increased accordingly, so the input buffer is always
 *  large enough the store a complete packet inclusive header) */
#define GPS_IN_BUFSIZ  (GARMIN_PKTHDR_LENGTH+MAX_SERIAL_PKT_SIZ)

/* size of a buffer able to hold a complete (incl. stuffing) packet */
#define GPS_OUT_BUFSIZ (GARMIN_PKTHDR_LENGTH+MAX_SERIAL_PKT_SIZ_STUFFED)

/* where to place the packet id of a serial packet, so we can
 * prepend the usb-packet header without the need to move the
 * packets data */
#define GSP_INITIAL_OFFSET (GARMIN_PKTHDR_LENGTH-2)

/* max. size of incoming private packets (header+1 param) */
#define PRIVPKTSIZ (GARMIN_PKTHDR_LENGTH+4)

#define GARMIN_LAYERID_TRANSPORT  0
#define GARMIN_LAYERID_APPL      20
/* our own layer-id to use for some control mechanisms */
#define GARMIN_LAYERID_PRIVATE	0x01106E4B

#define GARMIN_PKTID_PVT_DATA	51
#define GARMIN_PKTID_L001_COMMAND_DATA 10

#define CMND_ABORT_TRANSFER 0

/* packet ids used in private layer */
#define PRIV_PKTID_SET_DEBUG	1
#define PRIV_PKTID_SET_MODE	2
#define PRIV_PKTID_INFO_REQ	3
#define PRIV_PKTID_INFO_RESP	4
#define PRIV_PKTID_RESET_REQ	5
#define PRIV_PKTID_SET_DEF_MODE	6


#define ETX	0x03
#define DLE	0x10
#define ACK	0x06
#define NAK	0x15

/* structure used to queue incoming packets */
struct garmin_packet {
	struct list_head  list;
	int               seq;
	/* the real size of the data array, always > 0 */
	int               size;
	__u8              data[1];
};

/* structure used to keep the current state of the driver */
struct garmin_data {
	__u8   state;
	__u16  flags;
	__u8   mode;
	__u8   count;
	__u8   pkt_id;
	__u32  serial_num;
	struct timer_list timer;
	struct usb_serial_port *port;
	int    seq_counter;
	int    insize;
	int    outsize;
	__u8   inbuffer [GPS_IN_BUFSIZ];  /* tty -> usb */
	__u8   outbuffer[GPS_OUT_BUFSIZ]; /* usb -> tty */
	__u8   privpkt[4*6];
	spinlock_t lock;
	struct list_head pktlist;
};


#define STATE_NEW            0
#define STATE_INITIAL_DELAY  1
#define STATE_TIMEOUT        2
#define STATE_SESSION_REQ1   3
#define STATE_SESSION_REQ2   4
#define STATE_ACTIVE         5

#define STATE_RESET	     8
#define STATE_DISCONNECTED   9
#define STATE_WAIT_TTY_ACK  10
#define STATE_GSP_WAIT_DATA 11

#define MODE_NATIVE          0
#define MODE_GARMIN_SERIAL   1

/* Flags used in garmin_data.flags: */
#define FLAGS_SESSION_REPLY_MASK  0x00C0
#define FLAGS_SESSION_REPLY1_SEEN 0x0080
#define FLAGS_SESSION_REPLY2_SEEN 0x0040
#define FLAGS_BULK_IN_ACTIVE      0x0020
#define FLAGS_BULK_IN_RESTART     0x0010
#define FLAGS_THROTTLED           0x0008
#define APP_REQ_SEEN              0x0004
#define APP_RESP_SEEN             0x0002
#define CLEAR_HALT_REQUIRED       0x0001

#define FLAGS_QUEUING             0x0100
#define FLAGS_DROP_DATA           0x0800

#define FLAGS_GSP_SKIP            0x1000
#define FLAGS_GSP_DLESEEN         0x2000






/* function prototypes */
static int gsp_next_packet(struct garmin_data *garmin_data_p);
static int garmin_write_bulk(struct usb_serial_port *port,
			     const unsigned char *buf, int count,
			     int dismiss_ack);

/* some special packets to be send or received */
static unsigned char const GARMIN_START_SESSION_REQ[]
	= { 0, 0, 0, 0,  5, 0, 0, 0, 0, 0, 0, 0 };
static unsigned char const GARMIN_START_SESSION_REPLY[]
	= { 0, 0, 0, 0,  6, 0, 0, 0, 4, 0, 0, 0 };
static unsigned char const GARMIN_BULK_IN_AVAIL_REPLY[]
	= { 0, 0, 0, 0,  2, 0, 0, 0, 0, 0, 0, 0 };
static unsigned char const GARMIN_APP_LAYER_REPLY[]
	= { 0x14, 0, 0, 0 };
static unsigned char const GARMIN_START_PVT_REQ[]
	= { 20, 0, 0, 0,  10, 0, 0, 0, 2, 0, 0, 0, 49, 0 };
static unsigned char const GARMIN_STOP_PVT_REQ[]
	= { 20, 0, 0, 0,  10, 0, 0, 0, 2, 0, 0, 0, 50, 0 };
static unsigned char const GARMIN_STOP_TRANSFER_REQ[