/*
* called for a complete packet received from tty layer
*
* the complete packet (pktid ... cksum) is in garmin_data_p->inbuf starting
* at GSP_INITIAL_OFFSET.
*
* count - number of bytes in the input buffer including space reserved for
* the usb header: GSP_INITIAL_OFFSET + number of bytes in packet
* (including pkt-id, data-length a. cksum)
*/
static int gsp_rec_packet(struct garmin_data *garmin_data_p, int count)
{
unsigned long flags;
const __u8 *recpkt = garmin_data_p->inbuffer+GSP_INITIAL_OFFSET;
__le32 *usbdata = (__le32 *) garmin_data_p->inbuffer;
int cksum = 0;
int n = 0;
int pktid = recpkt[0];
int size = recpkt[1];
usb_serial_debug_data(debug, &garmin_data_p->port->dev,
__func__, count-GSP_INITIAL_OFFSET, recpkt);
if (size != (count-GSP_INITIAL_OFFSET-3)) {
dbg("%s - invalid size, expected %d bytes, got %d",
__func__, size, (count-GSP_INITIAL_OFFSET-3));
return -EINVPKT;
}
cksum += *recpkt++;
cksum += *recpkt++;
/* sanity check, remove after test ... */
if ((__u8 *)&(usbdata[3]) != recpkt) {
dbg("%s - ptr mismatch %p - %p",
__func__, &(usbdata[4]), recpkt);
return -EINVPKT;
}
while (n < size) {
cksum += *recpkt++;
n++;
}
if ((0xff & (cksum + *recpkt)) != 0) {
dbg("%s - invalid checksum, expected %02x, got %02x",
__func__, 0xff & -cksum, 0xff & *recpkt);
return -EINVPKT;
}
usbdata[0] = __cpu_to_le32(GARMIN_LAYERID_APPL);
usbdata[1] = __cpu_to_le32(pktid);
usbdata[2] = __cpu_to_le32(size);
garmin_write_bulk(garmin_data_p->port, garmin_data_p->inbuffer,
GARMIN_PKTHDR_LENGTH+size, 0);
/* if this was an abort-transfer command, flush all
queued data. */
if (isAbortTrfCmnd(garmin_data_p->inbuffer)) {
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags |= FLAGS_DROP_DATA;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
pkt_clear(garmin_data_p);
}
return count;
}
static int garmin_init_session(struct usb_serial_port *port)
{
struct usb_serial *serial = port->serial;
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
int status = 0;
int i = 0;
if (status == 0) {
usb_kill_urb(port->interrupt_in_urb);
dev_dbg(&serial->dev->dev, "%s - adding interrupt input\n", __func__);
status = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
if (status)
dev_err(&serial->dev->dev,
"%s - failed submitting interrupt urb, error %d\n",
__func__, status);
}
/*
* using the initialization method from gpsbabel. See comments in
* gpsbabel/jeeps/gpslibusb.c gusb_reset_toggles()
*/
if (status == 0) {
dev_dbg(&serial->dev->dev, "%s - starting session ...\n", __func__);
garmin_data_p->state = STATE_ACTIVE;
for (i = 0; i < 3; i++) {
status = garmin_write_bulk(port,
GARMIN_START_SESSION_REQ,
sizeof(GARMIN_START_SESSION_REQ), 0);
if (status < 0)
break;
}
if (status > 0)
status = 0;
}
return status;
}
/*
* Called for data received from tty
*
* The input data is expected to be in garmin usb-packet format.
*
* buf contains the data read, it may span more than one packet
* or even incomplete packets
*/
static int nat_receive(struct garmin_data *garmin_data_p,
const unsigned char *buf, int count)
{
unsigned long flags;
__u8 *dest;
int offs = 0;
int result = count;
int len;
while (offs < count) {
/* if buffer contains header, copy rest of data */
if (garmin_data_p->insize >= GARMIN_PKTHDR_LENGTH)
len = GARMIN_PKTHDR_LENGTH
+getDataLength(garmin_data_p->inbuffer);
else
len = GARMIN_PKTHDR_LENGTH;
if (len >= GPS_IN_BUFSIZ) {
/* seems to be an invalid packet, ignore rest
of input */
dev_dbg(&garmin_data_p->port->dev,
"%s - packet size too large: %d\n",
__func__, len);
garmin_data_p->insize = 0;
count = 0;
result = -EINVPKT;
} else {
len -= garmin_data_p->insize;
if (len > (count-offs))
len = (count-offs);
if (len > 0) {
dest = garmin_data_p->inbuffer
+ garmin_data_p->insize;
memcpy(dest, buf+offs, len);
garmin_data_p->insize += len;
offs += len;
}
}
/* do we have a complete packet ? */
if (garmin_data_p->insize >= GARMIN_PKTHDR_LENGTH) {
len = GARMIN_PKTHDR_LENGTH+
getDataLength(garmin_data_p->inbuffer);
if (garmin_data_p->insize >= len) {
garmin_write_bulk(garmin_data_p->port,
garmin_data_p->inbuffer,
len, 0);
garmin_data_p->insize = 0;
/* if this was an abort-transfer command,
flush all queued data. */
if (isAbortTrfCmnd(garmin_data_p->inbuffer)) {
spin_lock_irqsave(&garmin_data_p->lock,
flags);
garmin_data_p->flags |= FLAGS_DROP_DATA;
spin_unlock_irqrestore(
&garmin_data_p->lock, flags);
pkt_clear(garmin_data_p);
}
}
}
}
return result;
}
