garmin_gps.c

LINUX 2.6.17.4的源码

{
	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;

	dbg("%s - port %d, state %d", __FUNCTION__, port->number,
		garmin_data_p->state);

	garmin_data_p->flags &= ~FLAGS_DROP_DATA;

	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(debug, &port->dev, __FUNCTION__, count, buffer);

	usb_fill_bulk_urb (urb, serial->dev,
			 	usb_sndbulkpipe (serial->dev,
				port->bulk_out_endpointAddress),
				buffer, count,
				garmin_write_bulk_callback, port);
	urb->transfer_flags |= URB_ZERO_PACKET;

	if (GARMIN_LAYERID_APPL == getLayerId(buffer)) {
		garmin_data_p->flags |= FLAGS_APP_REQ_SEEN;
		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",
				__FUNCTION__, status);
		count = status;
	} else {

		if (GARMIN_LAYERID_APPL == getLayerId(buffer)
		    && (garmin_data_p->mode == MODE_GARMIN_SERIAL))  {

			gsp_send_ack(garmin_data_p, buffer[4]);
		}
	}

	/* 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;
}



static int garmin_write (struct usb_serial_port *port,
                         const unsigned char *buf, int count)
{
	int pktid, pktsiz, len;
	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
	__le32 *privpkt = (__le32 *)garmin_data_p->privpkt;

	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, buf);

	/* check for our private packets */
	if (count >= GARMIN_PKTHDR_LENGTH) {

		len = PRIVPKTSIZ;
		if (count < len)
			len = count;

		memcpy(garmin_data_p->privpkt, buf, len);

		pktsiz = getDataLength(garmin_data_p->privpkt);
		pktid  = getPacketId(garmin_data_p->privpkt);

		if (count == (GARMIN_PKTHDR_LENGTH+pktsiz)
		    && GARMIN_LAYERID_PRIVATE == getLayerId(garmin_data_p->privpkt)) {

			dbg("%s - processing private request %d",
				__FUNCTION__, pktid);

			// drop all unfinished transfers
			garmin_clear(garmin_data_p);

			switch(pktid) {

			case PRIV_PKTID_SET_DEBUG:
				if (pktsiz != 4)
					return -EINVPKT;
				debug = __le32_to_cpu(privpkt[3]);
				dbg("%s - debug level set to 0x%X",
					__FUNCTION__, debug);
				break;

			case PRIV_PKTID_SET_MODE:
				if (pktsiz != 4)
					return -EINVPKT;
				garmin_data_p->mode = __le32_to_cpu(privpkt[3]);
				dbg("%s - mode set to %d",
					__FUNCTION__, garmin_data_p->mode);
				break;

			case PRIV_PKTID_INFO_REQ:
				priv_status_resp(port);
				break;

			case PRIV_PKTID_RESET_REQ:
				garmin_data_p->flags |= FLAGS_APP_REQ_SEEN;
				break;

			case PRIV_PKTID_SET_DEF_MODE:
				if (pktsiz != 4)
					return -EINVPKT;
				initial_mode = __le32_to_cpu(privpkt[3]);
				dbg("%s - initial_mode set to %d",
					__FUNCTION__,
					garmin_data_p->mode);
				break;
			}
			return count;
		}
	}

	if (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
		return gsp_receive(garmin_data_p, buf, count);
	} else {	/* MODE_NATIVE */
		return nat_receive(garmin_data_p, buf, count);
	}
}


static int garmin_write_room (struct usb_serial_port *port)
{
	/*
	 * Report back the bytes currently available in the output buffer.
	 */
	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
	return GPS_OUT_BUFSIZ-garmin_data_p->outsize;
}


static int garmin_chars_in_buffer (struct usb_serial_port *port)
{
	/*
	 * Report back the number of bytes currently in our input buffer.
         * Will this lock up the driver - the buffer contains an incomplete
         * package which will not be written to the device until it
         * has been completed ?
         */
	//struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
	//return garmin_data_p->insize;
	return 0;
}


static void garmin_read_process(struct garmin_data * garmin_data_p,
				 unsigned char *data, unsigned data_length)
{
	if (garmin_data_p->flags & FLAGS_DROP_DATA) {
		/* abort-transfer cmd is actice */
		dbg("%s - pkt dropped", __FUNCTION__);
	} else if (garmin_data_p->state != STATE_DISCONNECTED &&
	           garmin_data_p->state != STATE_RESET ) {

		/* remember any appl.layer packets, so we know
		   if a reset is required or not when closing
		   the device */
		if (0 == memcmp(data, GARMIN_APP_LAYER_REPLY,
		                sizeof(GARMIN_APP_LAYER_REPLY)))
			garmin_data_p->flags |= FLAGS_APP_RESP_SEEN;

		/* if throttling is active or postprecessing is required
		   put the received data in th 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 (garmin_data_p->mode == MODE_GARMIN_SERIAL) {
			if (getLayerId(data) == GARMIN_LAYERID_APPL) {
				pkt_add(garmin_data_p, data, data_length);
			}
		} else {
			send_to_tty(garmin_data_p->port, data, data_length);
		}
	}
}


static void garmin_read_bulk_callback (struct urb *urb, struct pt_regs *regs)
{
	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
	struct usb_serial *serial =  port->serial;
	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
	unsigned char *data = urb->transfer_buffer;
	int status;

	dbg("%s - port %d", __FUNCTION__, port->number);

	if (!serial) {
		dbg("%s - bad serial pointer, exiting", __FUNCTION__);
		return;
	}

	if (urb->status) {
		dbg("%s - nonzero read bulk status received: %d",
			__FUNCTION__, urb->status);
		return;
	}

	usb_serial_debug_data(debug, &port->dev, 
				__FUNCTION__, urb->actual_length, data);

	garmin_read_process(garmin_data_p, data, urb->actual_length);

	/* Continue trying to read until nothing more is received  */
	if (urb->actual_length > 0) {
		usb_fill_bulk_urb (port->read_urb, serial->dev,
			   usb_rcvbulkpipe (serial->dev,
					    port->bulk_in_endpointAddress),
			   port->read_urb->transfer_buffer,
			   port->read_urb->transfer_buffer_length,
			   garmin_read_bulk_callback, port);
		status = usb_submit_urb(port->read_urb, GFP_ATOMIC);
		if (status)
			dev_err(&port->dev,
				"%s - failed resubmitting read urb, error %d\n",
			        __FUNCTION__, status);
	}
	return;
}


static void garmin_read_int_callback (struct urb *urb, struct pt_regs *regs)
{
	int status;
	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
	struct usb_serial *serial = port->serial;
	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);
	unsigned char *data = urb->transfer_buffer;

	switch (urb->status) {
	case 0:
		/* success */
		break;
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
		/* this urb is terminated, clean up */
		dbg("%s - urb shutting down with status: %d",
			__FUNCTION__, urb->status);
		return;
	default:
		dbg("%s - nonzero urb status received: %d",
			__FUNCTION__, urb->status);
		return;
	}

	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, 
				urb->actual_length, urb->transfer_buffer);

	if (urb->actual_length == sizeof(GARMIN_BULK_IN_AVAIL_REPLY) &&
	    0 == memcmp(data, GARMIN_BULK_IN_AVAIL_REPLY,
		        sizeof(GARMIN_BULK_IN_AVAIL_REPLY))) {

		dbg("%s - bulk data available.", __FUNCTION__);

		/* bulk data available */
		usb_fill_bulk_urb (port->read_urb, serial->dev,
				usb_rcvbulkpipe (serial->dev,
				port->bulk_in_endpointAddress),
				port->read_urb->transfer_buffer,
				port->read_urb->transfer_buffer_length,
				garmin_read_bulk_callback, port);
		status = usb_submit_urb(port->read_urb, GFP_KERNEL);
		if (status) {
			dev_err(&port->dev,
				"%s - failed submitting read urb, error %d\n",
			__FUNCTION__, status);
		}

	} else if (urb->actual_length == (4+sizeof(GARMIN_START_SESSION_REPLY))
			 && 0 == memcmp(data, GARMIN_START_SESSION_REPLY,
			                sizeof(GARMIN_START_SESSION_REPLY))) {

		garmin_data_p->flags |= FLAGS_SESSION_REPLY1_SEEN;

		/* save the serial number */
		garmin_data_p->serial_num 
			= __le32_to_cpup((__le32*)(data+GARMIN_PKTHDR_LENGTH));

		dbg("%s - start-of-session reply seen - serial %u.",
			__FUNCTION__, garmin_data_p->serial_num);
	}

	if (garmin_data_p->ignorePkts) {
		/* this reply belongs to a request generated by the driver,
		   ignore it. */
		dbg("%s - pkt ignored (%d)",
			__FUNCTION__, garmin_data_p->ignorePkts);
		garmin_data_p->ignorePkts--;
	} else {
		garmin_read_process(garmin_data_p, data, urb->actual_length);
	}

	port->interrupt_in_urb->dev = port->serial->dev;
	status = usb_submit_urb (urb, GFP_ATOMIC);
	if (status)
		dev_err(&urb->dev->dev,
			"%s - Error %d submitting interrupt urb\n",
			__FUNCTION__, status);
}


/*
 * 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)
{
	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 {
			garmin_data_p->flags &= ~FLAGS_QUEUING;
		}
	}
	return 0;
}


static void garmin_throttle (struct usb_serial_port *port)
{
	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);

	dbg("%s - port %d", __FUNCTION__, port->number);
	/* set flag, data received will be put into a queue
	   for later processing */
	garmin_data_p->flags |= FLAGS_QUEUING|FLAGS_THROTTLED;
}


static void garmin_unthrottle (struct usb_serial_port *port)
{
	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);

	dbg("%s - port %d", __FUNCTION__, port->number);
	garmin_data_p->flags &= ~FLAGS_THROTTLED;

	/* in native mode send queued data to tty, in
	   serial mode nothing needs to be done here */
	if (garmin_data_p->mode == MODE_NATIVE)
		garmin_flush_queue(garmin_data_p);
}



/*
 * The timer is currently only used to send queued packets to
 * the tty in cases where the protocol provides no own handshaking
 * to initiate the transfer.
 */
static void timeout_handler(unsigned long data)
{
	struct garmin_data *garmin_data_p = (struct garmin_data *) data;

	/* send the next queued packet to the tty port */
	if (garmin_data_p->mode == MODE_NATIVE)
		if (garmin_data_p->flags & FLAGS_QUEUING)
			garmin_flush_queue(garmin_data_p);
}



static int garmin_attach (struct usb_serial *serial)
{
	int status = 0;
	struct usb_serial_port *port = serial->port[0];
	struct garmin_data * garmin_data_p = NULL;

	dbg("%s", __FUNCTION__);

	garmin_data_p = kzalloc(sizeof(struct garmin_data), GFP_KERNEL);
	if (garmin_data_p == NULL) {
		dev_err(&port->dev, "%s - Out of memory\n", __FUNCTION__);
		return -ENOMEM;
	}
	init_timer(&garmin_data_p->timer);
	spin_lock_init(&garmin_data_p->lock);
	INIT_LIST_HEAD(&garmin_data_p->pktlist);
	//garmin_data_p->timer.expires = jiffies + session_timeout;
	garmin_data_p->timer.data = (unsigned long)garmin_data_p;
	garmin_data_p->timer.function = timeout_handler;
	garmin_data_p->port = port;
	garmin_data_p->state = 0;
	garmin_data_p->count = 0;
	usb_set_serial_port_data(port, garmin_data_p);

	status = garmin_init_session(port);

	return status;
}


static void garmin_shutdown (struct usb_serial *serial)
{
	struct usb_serial_port *port = serial->port[0];
	struct garmin_data * garmin_data_p = usb_get_serial_port_data(port);

	dbg("%s", __FUNCTION__);

	usb_kill_urb (port->interrupt_in_urb);
	del_timer_sync(&garmin_data_p->timer);
	kfree (garmin_data_p);
	usb_set_serial_port_data(port, NULL);
}


/* All of the device info needed */
static struct usb_serial_driver garmin_device = {
	.driver = {
		.owner =	THIS_MODULE,
		.name =		"garmin_gps",
	},
	.description =		"Garmin GPS usb/tty",
	.id_table            = id_table,
	.num_interrupt_in    = 1,
	.num_bulk_in         = 1,
	.num_bulk_out        = 1,
	.num_ports           = 1,
	.open                = garmin_open,
	.close               = garmin_close,
	.throttle            = garmin_throttle,
	.unthrottle          = garmin_unthrottle,
	.attach              = garmin_attach,
	.shutdown            = garmin_shutdown,
	.write               = garmin_write,
	.write_room          = garmin_write_room,
	.chars_in_buffer     = garmin_chars_in_buffer,
	.write_bulk_callback = garmin_write_bulk_callback,
	.read_bulk_callback  = garmin_read_bulk_callback,
	.read_int_callback   = garmin_read_int_callback,
};


static int __init garmin_init (void)
{
	int retval;

	retval = usb_serial_register(&garmin_device);
	if (retval)
		goto failed_garmin_register;
	retval = usb_register(&garmin_driver);
	if (retval)
		goto failed_usb_register;
	info(DRIVER_DESC " " DRIVER_VERSION);

	return 0;
failed_usb_register:
	usb_serial_deregister(&garmin_device);
failed_garmin_register:
	return retval;
}


static void __exit garmin_exit (void)
{
	usb_deregister (&garmin_driver);
	usb_serial_deregister (&garmin_device);
}




module_init(garmin_init);
module_exit(garmin_exit);

MODULE_AUTHOR( DRIVER_AUTHOR );
MODULE_DESCRIPTION( DRIVER_DESC );
MODULE_LICENSE("GPL");

module_param(debug, bool, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(debug, "Debug enabled or not");
module_param(initial_mode, int, S_IRUGO);
MODULE_PARM_DESC(initial_mode, "Initial mode");