/*
* 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;
}
/*
* clear all cached data
*/
static int garmin_clear(struct garmin_data *garmin_data_p)
{
unsigned long flags;
/* flush all queued data */
pkt_clear(garmin_data_p);
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->insize = 0;
garmin_data_p->outsize = 0;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
return 0;
}
static int garmin_write_bulk(struct usb_serial_port *port,
const unsigned char *buf, int count,
int dismiss_ack)
{
unsigned long flags;
struct usb_serial *serial = port->serial;
struct garmin_data *garmin_data_p = usb_get_serial_port_data(port);
struct urb *urb;
unsigned char *buffer;
int status;
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags &= ~FLAGS_DROP_DATA;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
buffer = kmalloc(count, GFP_ATOMIC);
if (!buffer) {
dev_err(&port->dev, "out of memory\n");
return -ENOMEM;
}
urb = usb_alloc_urb(0, GFP_ATOMIC);
if (!urb) {
dev_err(&port->dev, "no more free urbs\n");
kfree(buffer);
return -ENOMEM;
}
memcpy(buffer, buf, count);
usb_serial_debug_data(&port->dev, __func__, count, buffer);
usb_fill_bulk_urb(urb, serial->dev,
usb_sndbulkpipe(serial->dev,
port->bulk_out_endpointAddress),
buffer, count,
garmin_write_bulk_callback,
dismiss_ack ? NULL : port);
urb->transfer_flags |= URB_ZERO_PACKET;
if (GARMIN_LAYERID_APPL == getLayerId(buffer)) {
spin_lock_irqsave(&garmin_data_p->lock, flags);
garmin_data_p->flags |= APP_REQ_SEEN;
spin_unlock_irqrestore(&garmin_data_p->lock, flags);
if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
pkt_clear(garmin_data_p);
garmin_data_p->state = STATE_GSP_WAIT_DATA;
}
}
/* send it down the pipe */
status = usb_submit_urb(urb, GFP_ATOMIC);
if (status) {
dev_err(&port->dev,
"%s - usb_submit_urb(write bulk) failed with status = %d\n",
__func__, status);
count = status;
}
/* we are done with this urb, so let the host driver
* really free it when it is finished with it */
usb_free_urb(urb);
return count;
}
/*
* 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;
}