ir-usb.c

基于S3CEB2410平台LINUX操作系统下 USB驱动源代码

	down (&port->sem);

	--port->open_count;

	if (port->open_count <= 0) {
		if (serial->dev) {
			/* shutdown our bulk read */
			usb_unlink_urb (port->read_urb);
		}
		port->active = 0;
		port->open_count = 0;

	}
	up (&port->sem);
	MOD_DEC_USE_COUNT;
}

static int ir_write (struct usb_serial_port *port, int from_user, const unsigned char *buf, int count)
{
	unsigned char *transfer_buffer;
	int result;
	int transfer_size;

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

	if (!port->tty) {
		err ("%s - no tty???", __FUNCTION__);
		return 0;
	}

	if (count == 0)
		return 0;

	if (port->write_urb->status == -EINPROGRESS) {
		dbg ("%s - already writing", __FUNCTION__);
		return 0;
	}

	transfer_buffer = port->write_urb->transfer_buffer;
	transfer_size = min(count, port->bulk_out_size - 1);

	/*
	 * The first byte of the packet we send to the device contains an
	 * inband header which indicates an additional number of BOFs and
	 * a baud rate change.
	 *
	 * See section 5.4.2.2 of the USB IrDA spec.
	 */
	*transfer_buffer = ir_xbof | ir_baud;
	++transfer_buffer;

	if (from_user) {
		if (copy_from_user (transfer_buffer, buf, transfer_size))
			return -EFAULT;
	} else {
		memcpy (transfer_buffer, buf, transfer_size);
	}

	usb_fill_bulk_urb (
		port->write_urb,
		port->serial->dev,
		usb_sndbulkpipe(port->serial->dev,
			port->bulk_out_endpointAddress),
		port->write_urb->transfer_buffer,
		transfer_size + 1,
		ir_write_bulk_callback,
		port);

	port->write_urb->transfer_flags
		= USB_QUEUE_BULK
		| USB_ZERO_PACKET;

	result = usb_submit_urb (port->write_urb);
	if (result)
		err("%s - failed submitting write urb, error %d", __FUNCTION__, result);
	else
		result = transfer_size;

	return result;
}

static void ir_write_bulk_callback (struct urb *urb)
{
	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;

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

	usb_serial_debug_data (
		__FILE__,
		__FUNCTION__,
		urb->actual_length,
		urb->transfer_buffer);

	queue_task(&port->tqueue, &tq_immediate);
	mark_bh(IMMEDIATE_BH);
	
	return;
}

static void ir_read_bulk_callback (struct urb *urb)
{
	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);
	struct tty_struct *tty;
	unsigned char *data = urb->transfer_buffer;
	int result;

	if (port_paranoia_check (port, __FUNCTION__))
		return;

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

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

	if (!port->active) {
		dbg("%s - port closed.", __FUNCTION__);
		return;
	}

	switch (urb->status) {

		case 0: /* Successful */

			/*
			 * The first byte of the packet we get from the device
			 * contains a busy indicator and baud rate change.
			 * See section 5.4.1.2 of the USB IrDA spec.
			 */
			if((*data & 0x0f) > 0) ir_baud = *data & 0x0f;

			usb_serial_debug_data (
				__FILE__,
				__FUNCTION__,
				urb->actual_length,
				data);

			/*
			 * Bypass flip-buffers, and feed the ldisc directly
			 * due to our potentally large buffer size.  Since we
			 * used to set low_latency, this is exactly what the
			 * tty layer did anyway :)
			 */
			tty = port->tty;

			tty->ldisc.receive_buf(
				tty,
				data+1,
				NULL,
				urb->actual_length-1);

			/*
			 * No break here.
			 * We want to resubmit the urb so we can read
			 * again.
			 */

		case -EPROTO: /* taking inspiration from pl2303.c */

			/* Continue trying to always read */
			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,
				ir_read_bulk_callback,
				port);

			port->read_urb->transfer_flags = USB_QUEUE_BULK;

			result = usb_submit_urb(port->read_urb);

			if (result)
				err("%s - failed resubmitting read urb, error %d",
					__FUNCTION__, 
					result);

			break ;

		default:
			dbg("%s - nonzero read bulk status received: %d",
				__FUNCTION__, 
				urb->status);
			break ;

	}

	return;
}

static void ir_set_termios (struct usb_serial_port *port, struct termios *old_termios)
{
	unsigned char *transfer_buffer;
	unsigned int cflag;
	int result;

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

	if ((!port->tty) || (!port->tty->termios)) {
		dbg("%s - no tty structures", __FUNCTION__);
		return;
	}

	cflag = port->tty->termios->c_cflag;
	/* check that they really want us to change something */
	if (old_termios) {
		if ((cflag == old_termios->c_cflag) &&
		    (RELEVANT_IFLAG(port->tty->termios->c_iflag) == RELEVANT_IFLAG(old_termios->c_iflag))) {
			dbg("%s - nothing to change...", __FUNCTION__);
			return;
		}
	}

	/* All we can change is the baud rate */
	if (cflag & CBAUD) {

		dbg ("%s - asking for baud %d",
			__FUNCTION__,
			tty_get_baud_rate(port->tty));

		/* 
		 * FIXME, we should compare the baud request against the
		 * capability stated in the IR header that we got in the
		 * startup funtion.
		 */
		switch (cflag & CBAUD) {
			case B2400:    ir_baud = SPEED_2400;    break;
			default:
			case B9600:    ir_baud = SPEED_9600;    break;
			case B19200:   ir_baud = SPEED_19200;   break;
			case B38400:   ir_baud = SPEED_38400;   break;
			case B57600:   ir_baud = SPEED_57600;   break;
			case B115200:  ir_baud = SPEED_115200;  break;
			case B576000:  ir_baud = SPEED_576000;  break;
			case B1152000: ir_baud = SPEED_1152000; break;
			case B4000000: ir_baud = SPEED_4000000; break;
		}

		if (xbof == -1) {
			ir_xbof = ir_xbof_change(ir_add_bof);
		} else {
			ir_xbof = ir_xbof_change(xbof) ;
		}

		/* Notify the tty driver that the termios have changed. */
		port->tty->ldisc.set_termios(port->tty, NULL);

		/* FIXME need to check to see if our write urb is busy right
		 * now, or use a urb pool.
		 *
		 * send the baud change out on an "empty" data packet
		 */
		transfer_buffer = port->write_urb->transfer_buffer;
		*transfer_buffer = ir_xbof | ir_baud;

		usb_fill_bulk_urb (
			port->write_urb,
			port->serial->dev,
			usb_sndbulkpipe(port->serial->dev,
				port->bulk_out_endpointAddress),
			port->write_urb->transfer_buffer,
			1,
			ir_write_bulk_callback,
			port);

		port->write_urb->transfer_flags
			= USB_QUEUE_BULK
			| USB_ZERO_PACKET;

		result = usb_submit_urb (port->write_urb);
		if (result)
			err("%s - failed submitting write urb, error %d", __FUNCTION__, result);
	}
	return;
}


static int __init ir_init (void)
{
	usb_serial_register (&ir_device);
	info(DRIVER_DESC " " DRIVER_VERSION);
	return 0;
}


static void __exit ir_exit (void)
{
	usb_serial_deregister (&ir_device);
}


module_init(ir_init);
module_exit(ir_exit);

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

MODULE_PARM(debug, "i");
MODULE_PARM_DESC(debug, "Debug enabled or not");
MODULE_PARM(xbof, "i");
MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
MODULE_PARM(buffer_size, "i");
MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");