garminusb.h

/*
    Definitions for Garmin USB protocol and implementation.

    Copyright (C) 2004, 2005, 2006 Robert Lipe, robertlipe@usa.net

    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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

 */
#include <cstdio>
#include "jeeps/gpsdevice.h"

/* This structure is a bit funny looking to avoid variable length
 * arrays which aren't present in C89.   This contains the visible
 * fields in the USB packets of the Garmin USB receivers (60C, 76C, etc.)
 * All data are little endian.
 */
typedef
union {
  struct {
    unsigned char type;
    unsigned char reserved1;
    unsigned char reserved2;
    unsigned char reserved3;
    unsigned char pkt_id[2];
    unsigned char reserved6;
    unsigned char reserved7;
    unsigned char datasz[4];
    unsigned char databuf[1]; /* actually an variable length array... */
  } gusb_pkt;
  unsigned char dbuf[1024];
} garmin_usb_packet;

/*
 * Internal interfaces that are common regardless of underlying
 * OS implementation.
 */
#define GUSB_MAX_UNITS 20
typedef struct {
  unsigned long serial_number;
  unsigned long unit_id;
  unsigned long unit_version;
  char* os_identifier; /* In case the OS has another name for it. */
  char* product_identifier; /* From the hardware itself. */
} garmin_unit_info_t;

extern garmin_unit_info_t garmin_unit_info[GUSB_MAX_UNITS];

int gusb_cmd_send(const garmin_usb_packet* obuf, size_t sz);
int gusb_cmd_get(garmin_usb_packet* ibuf, size_t sz);
int gusb_init(const char* portname, gpsdevh** dh);
int gusb_close(gpsdevh*, bool exit_lib = true);

/*
 * New packet types in USB.
 */
#define GUSB_SESSION_START 5	/* We request units attention */
#define GUSB_SESSION_ACK   6	/* Unit responds that we have its attention */
#define GUSB_REQUEST_BULK  2	/* Unit requests we read from bulk pipe */