/* send an ack packet back to the tty */
static int gsp_send_ack(struct garmin_data *garmin_data_p, __u8 pkt_id)
{
__u8 pkt[10];
__u8 cksum = 0;
__u8 *ptr = pkt;
unsigned l = 0;
dbg("%s - pkt-id: 0x%X.", __func__, 0xFF & pkt_id);
*ptr++ = DLE;
*ptr++ = ACK;
cksum += ACK;
*ptr++ = 2;
cksum += 2;
*ptr++ = pkt_id;
cksum += pkt_id;
if (pkt_id == DLE)
*ptr++ = DLE;
*ptr++ = 0;
*ptr++ = 0xFF & (-cksum);
*ptr++ = DLE;
*ptr++ = ETX;
l = ptr-pkt;
send_to_tty(garmin_data_p->port, pkt, l);
return 0;
}
static void garmin_read_process(struct garmin_data *garmin_data_p,
unsigned char *data, unsigned data_length,
int bulk_data)
{
unsigned long flags;
if (garmin_data_p->flags & FLAGS_DROP_DATA) {
/* abort-transfer cmd is actice */
dev_dbg(&garmin_data_p->port->dev, "%s - pkt dropped\n", __func__);
} else if (garmin_data_p->state != STATE_DISCONNECTED &&
garmin_data_p->state != STATE_RESET) {
/* if throttling is active or postprecessing is required
put the received data in the input queue, otherwise
send it directly to the tty port */
if (garmin_data_p->flags & FLAGS_QUEUING) {
pkt_add(garmin_data_p, data, data_length);
} else if (bulk_data ||
getLayerId(data) == GARMIN_LAYERID_APPL) {
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags |= APP_RESP_SEEN;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
pkt_add(garmin_data_p, data, data_length);
} else {
send_to_tty(garmin_data_p->port, data,
data_length);
}
}
/* ignore system layer packets ... */
}
}
static void priv_status_resp(struct usb_serial_port *port)
{
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
__le32 *pkt = (__le32 *)garmin_data_p->privpkt;
pkt[0] = __cpu_to_le32(GARMIN_LAYERID_PRIVATE);
pkt[1] = __cpu_to_le32(PRIV_PKTID_INFO_RESP);
pkt[2] = __cpu_to_le32(12);
pkt[3] = __cpu_to_le32(VERSION_MAJOR << 16 | VERSION_MINOR);
pkt[4] = __cpu_to_le32(garmin_data_p->mode);
pkt[5] = __cpu_to_le32(garmin_data_p->serial_num);
send_to_tty(port, (__u8 *)pkt, 6 * 4);
}
/*
* Sends the next queued packt to the tty port (garmin native mode only)
* and then sets a timer to call itself again until all queued data
* is sent.
*/
static int garmin_flush_queue(struct garmin_data *garmin_data_p)
{
unsigned long flags;
struct garmin_packet *pkt;
if ((garmin_data_p->flags & FLAGS_THROTTLED) == 0) {
pkt = pkt_pop(garmin_data_p);
if (pkt != NULL) {
send_to_tty(garmin_data_p->port, pkt->data, pkt->size);
kfree(pkt);
mod_timer(&garmin_data_p->timer, (1)+jiffies);
} else {
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags &= ~FLAGS_QUEUING;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
}
}
return 0;
}
/*
* Sends a usb packet to the tty
*
* Assumes, that all packages and at an usb-packet boundary.
*
* return <0 on error, 0 if packet is incomplete or > 0 if packet was sent
*/
static int gsp_send(struct garmin_data *garmin_data_p,
const unsigned char *buf, int count)
{
struct device *dev = &garmin_data_p->port->dev;
const unsigned char *src;
unsigned char *dst;
int pktid = 0;
int datalen = 0;
int cksum = 0;
int i = 0;
int k;
dev_dbg(dev, "%s - state %d - %d bytes.\n", __func__,
garmin_data_p->state, count);
k = garmin_data_p->outsize;
if ((k+count) > GPS_OUT_BUFSIZ) {
dev_dbg(dev, "packet too large\n");
garmin_data_p->outsize = 0;
return -4;
}
memcpy(garmin_data_p->outbuffer+k, buf, count);
k += count;
garmin_data_p->outsize = k;
if (k >= GARMIN_PKTHDR_LENGTH) {
pktid = getPacketId(garmin_data_p->outbuffer);
datalen = getDataLength(garmin_data_p->outbuffer);
i = GARMIN_PKTHDR_LENGTH + datalen;
if (k < i)
return 0;
} else {
return 0;
}
dev_dbg(dev, "%s - %d bytes in buffer, %d bytes in pkt.\n", __func__, k, i);
/* garmin_data_p->outbuffer now contains a complete packet */
usb_serial_debug_data(&garmin_data_p->port->dev, __func__, k,
garmin_data_p->outbuffer);
garmin_data_p->outsize = 0;
if (GARMIN_LAYERID_APPL != getLayerId(garmin_data_p->outbuffer)) {
dev_dbg(dev, "not an application packet (%d)\n",
getLayerId(garmin_data_p->outbuffer));
return -1;
}
if (pktid > 255) {
dev_dbg(dev, "packet-id %d too large\n", pktid);
return -2;
}
if (datalen > 255) {
dev_dbg(dev, "packet-size %d too large\n", datalen);
return -3;
}
/* the serial protocol should be able to handle this packet */
k = 0;
src = garmin_data_p->outbuffer+GARMIN_PKTHDR_LENGTH;
for (i = 0; i < datalen; i++) {
if (*src++ == DLE)
k++;
}
src = garmin_data_p->outbuffer+GARMIN_PKTHDR_LENGTH;
if (k > (GARMIN_PKTHDR_LENGTH-2)) {
/* can't add stuffing DLEs in place, move data to end
of buffer ... */
dst = garmin_data_p->outbuffer+GPS_OUT_BUFSIZ-datalen;
memcpy(dst, src, datalen);
src = dst;
}
dst = garmin_data_p->outbuffer;
*dst++ = DLE;
*dst++ = pktid;
cksum += pktid;
*dst++ = datalen;
cksum += datalen;
if (datalen == DLE)
*dst++ = DLE;
for (i = 0; i < datalen; i++) {
__u8 c = *src++;
*dst++ = c;
cksum += c;
if (c == DLE)
*dst++ = DLE;
}
cksum = 0xFF & -cksum;
*dst++ = cksum;
if (cksum == DLE)
*dst++ = DLE;
*dst++ = DLE;
*dst++ = ETX;
i = dst-garmin_data_p->outbuffer;
send_to_tty(garmin_data_p->port, garmin_data_p->outbuffer, i);
garmin_data_p->pkt_id = pktid;
garmin_data_p->state = STATE_WAIT_TTY_ACK;
return i;
}
