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Commit 648d4e16 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
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USB: serial: opticon: add write support 



This patch allows data to be sent to the scanner.

Cc: Kees Stoop <kees.stoop@opticon.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent f6d92a05

drivers/usb/serial/opticon.c

+122 −2
Original line number Diff line number Diff line 
/*

 * Opticon USB barcode to serial driver

 *

 * Copyright (C) 2008 Greg Kroah-Hartman <gregkh@suse.de>

 * Copyright (C) 2008 Novell Inc.

 * Copyright (C) 2008 - 2009 Greg Kroah-Hartman <gregkh@suse.de>

 * Copyright (C) 2008 - 2009 Novell Inc.

 *

 *	This program is free software; you can redistribute it and/or

 *	modify it under the terms of the GNU General Public License version
@@ -40,8 +40,12 @@ struct opticon_private { 
	bool throttled;

	bool actually_throttled;

	bool rts;

	int outstanding_urbs;

};



/* max number of write urbs in flight */

#define URB_UPPER_LIMIT	4



static void opticon_bulk_callback(struct urb *urb)

{

	struct opticon_private *priv = urb->context;
@@ -188,6 +192,120 @@ static void opticon_close(struct tty_struct *tty, struct usb_serial_port *port, 
	usb_kill_urb(priv->bulk_read_urb);

}



static void opticon_write_bulk_callback(struct urb *urb)

{

	struct opticon_private *priv = urb->context;

	int status = urb->status;

	unsigned long flags;



	/* free up the transfer buffer, as usb_free_urb() does not do this */

	kfree(urb->transfer_buffer);



	if (status)

		dbg("%s - nonzero write bulk status received: %d",

		    __func__, status);



	spin_lock_irqsave(&priv->lock, flags);

	--priv->outstanding_urbs;

	spin_unlock_irqrestore(&priv->lock, flags);



	usb_serial_port_softint(priv->port);

}



static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,

			 const unsigned char *buf, int count)

{

	struct opticon_private *priv = usb_get_serial_data(port->serial);

	struct usb_serial *serial = port->serial;

	struct urb *urb;

	unsigned char *buffer;

	unsigned long flags;

	int status;



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



	spin_lock_irqsave(&priv->lock, flags);

	if (priv->outstanding_urbs > URB_UPPER_LIMIT) {

		spin_unlock_irqrestore(&priv->lock, flags);

		dbg("%s - write limit hit\n", __func__);

		return 0;

	}

	priv->outstanding_urbs++;

	spin_unlock_irqrestore(&priv->lock, flags);



	buffer = kmalloc(count, GFP_ATOMIC);

	if (!buffer) {

		dev_err(&port->dev, "out of memory\n");

		count = -ENOMEM;

		goto error_no_buffer;

	}



	urb = usb_alloc_urb(0, GFP_ATOMIC);

	if (!urb) {

		dev_err(&port->dev, "no more free urbs\n");

		count = -ENOMEM;

		goto error_no_urb;

	}



	memcpy(buffer, buf, count);



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



	usb_fill_bulk_urb(urb, serial->dev,

			  usb_sndbulkpipe(serial->dev,

					  port->bulk_out_endpointAddress),

			  buffer, count, opticon_write_bulk_callback, priv);



	/* 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;

		goto error;

	}



	/* 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;

error:

	usb_free_urb(urb);

error_no_urb:

	kfree(buffer);

error_no_buffer:

	spin_lock_irqsave(&priv->lock, flags);

	--priv->outstanding_urbs;

	spin_unlock_irqrestore(&priv->lock, flags);

	return count;

}



static int opticon_write_room(struct tty_struct *tty)

{

	struct usb_serial_port *port = tty->driver_data;

	struct opticon_private *priv = usb_get_serial_data(port->serial);

	unsigned long flags;



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



	/*

	 * We really can take almost anything the user throws at us

	 * but let's pick a nice big number to tell the tty

	 * layer that we have lots of free space, unless we don't.

	 */

	spin_lock_irqsave(&priv->lock, flags);

	if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {

		spin_unlock_irqrestore(&priv->lock, flags);

		dbg("%s - write limit hit\n", __func__);

		return 0;

	}

	spin_unlock_irqrestore(&priv->lock, flags);



	return 2048;

}



static void opticon_throttle(struct tty_struct *tty)

{

	struct usb_serial_port *port = tty->driver_data;
@@ -352,6 +470,8 @@ static struct usb_serial_driver opticon_device = { 
	.attach =		opticon_startup,

	.open =			opticon_open,

	.close =		opticon_close,

	.write =		opticon_write,

	.write_room = 		opticon_write_room,

	.shutdown =		opticon_shutdown,

	.throttle = 		opticon_throttle,

	.unthrottle =		opticon_unthrottle,