void
gusb_syncup(void)
{
static int unit_number;
static const char oinit[12] =
{0, 0, 0, 0, GUSB_SESSION_START, 0, 0, 0, 0, 0, 0, 0};
garmin_usb_packet iresp;
int i;
/*
* This is our first communication with the unit.
*/
receive_state = rs_fromintr;
for(i = 0; i < 25; i++) {
le_write16(&iresp.gusb_pkt.pkt_id, 0);
le_write32(&iresp.gusb_pkt.datasz, 0);
le_write32(&iresp.gusb_pkt.databuf, 0);
gusb_cmd_send((const garmin_usb_packet *) oinit, sizeof(oinit));
gusb_cmd_get(&iresp, sizeof(iresp));
if ((le_read16(iresp.gusb_pkt.pkt_id) == GUSB_SESSION_ACK) &&
(le_read32(iresp.gusb_pkt.datasz) == 4)) {
unsigned serial_number = le_read32(iresp.gusb_pkt.databuf);
garmin_unit_info[unit_number].serial_number = serial_number;
gusb_id_unit(&garmin_unit_info[unit_number]);
unit_number++;
return;
}
}
fatal("Unable to establish USB syncup\n");
}
int32
GPS_Write_Packet_usb(gpsdevh *dh, GPS_PPacket packet)
{
garmin_usb_packet gp;
memset(&gp, 0, sizeof(gp));
/*
* Take the "portable" GPS_Packet data and put them into
* the USB packet that we will put on the wire.
*/
gp.gusb_pkt.type = 0x14;
le_write16(&gp.gusb_pkt.pkt_id, packet->type);
le_write32(&gp.gusb_pkt.datasz, packet->n );
memcpy(&gp.gusb_pkt.databuf, packet->data, packet->n);
return gusb_cmd_send(&gp, packet->n + 12);
}
/*
* This was a function of great joy to discover...and even greater to maintain.
*
* It turns out that as of 5/2006, every Garmin USB product has a problem
* where the device does not reset the data toggles after a configuration
* set. After a reset, the toggles both match. So we tear through the
* conversation and life is good. Unfortunately, the second time through,
* if we had an odd number of transactions in the previous conversation,
* we send a configuration set and reset the toggle on the HCI but the
* toggle on the device's end of the pipe is now out of whack which means
* that the subsequent transaction will hang.
*
* This isn't a problem in Windows since the configuration set is done only
* once there.
*
* This code has been tested in loops of 1000 cycles on Linux and OS/X and
* it seems to cure this at a mere cost of complexity and startup time. I'll
* be delighted when all the firmware gets revved and updated and we can
* remove this.
*
* 9/2008 But wait, there's more. The very toggle reset that we *had* to
* implement in 2006 to make non-Windows OSes work actually locks up verion
* 2.70 of the Venture HC. On that model, the second product request
* (you know, the one that we *use*, locks that device's protocol stack
* after the RET2INTR that immediately follows the REQBLK (and why is it
* telling us to go into bulk mode followed by an immeidate EOF, anyway?)
* that follows the request for product ID. 100% reproducible on Mac and
* Linux. Of course, we don't see this on the Windows system becuase
* we don't have to jump through hooops to clear the spec-violating out
* of state toggles there becuase those systems see only one configuration
* set ever.
*
* Grrrr!
*/
unsigned
gusb_reset_toggles(void)
{
static const char oinit[12] =
{0, 0, 0, 0, GUSB_SESSION_START, 0, 0, 0, 0, 0, 0, 0};
static const char oid[12] =
{20, 0, 0, 0, 0xfe, 0, 0, 0, 0, 0, 0, 0};
garmin_usb_packet iresp;
int t;
unsigned rv = 0;
/* Start off with three session starts.
* #1 resets the bulk out toggle. It may not make it to the device.
* #2 resets the the intr in toggle. It will make it to the device
* since #1 reset the the bulk out toggle. The device will
* respond on the intr in pipe which will clear its toggle.
* #3 actually starts the session now that the above are both clear.
*/
gusb_cmd_send((const garmin_usb_packet *) oinit, sizeof(oinit));
gusb_cmd_send((const garmin_usb_packet *) oinit, sizeof(oinit));
gusb_cmd_send((const garmin_usb_packet *) oinit, sizeof(oinit));
t = 10;
while(1) {
le_write16(&iresp.gusb_pkt.pkt_id, 0);
le_write32(&iresp.gusb_pkt.datasz, 0);
le_write32(&iresp.gusb_pkt.databuf, 0);
gusb_cmd_get(&iresp, sizeof(iresp));
if ((le_read16(iresp.gusb_pkt.pkt_id) == GUSB_SESSION_ACK) &&
(le_read32(iresp.gusb_pkt.datasz) == 4)) {
break;
}
if (t-- <= 0) {
fatal("Could not start session in a reasonable number of tries.\n");
}
}
/*
* Now that the bulk out and intr in packets are good, we send
* a product ID. On devices that respond totally on the intr
* pipe, this does nothing interesting, but on devices that respon
* on the bulk pipe this will reset the toggles on the bulk in.
*/
t = 10;
gusb_cmd_send((const garmin_usb_packet *) oid, sizeof(oid));
while(1) {
le_write16(&iresp.gusb_pkt.pkt_id, 0);
le_write32(&iresp.gusb_pkt.datasz, 0);
le_write32(&iresp.gusb_pkt.databuf, 0);
gusb_cmd_get(&iresp, sizeof(iresp));
if (le_read16(iresp.gusb_pkt.pkt_id) == 0xff) {
rv = le_read16(iresp.gusb_pkt.databuf+0);
}
if (le_read16(iresp.gusb_pkt.pkt_id) == 0xfd) return rv;
if (t-- <= 0) {
fatal("Could not start session in a reasonable number of tries.\n");
}
}
return 0;
}
