drivers/usb/serial/symbolserial.c - kernel/prism - Git at Google

 /*
  * Symbol USB barcode to serial driver
  *
  * Copyright (C) 2009 Greg Kroah-Hartman <gregkh@suse.de>
  * Copyright (C) 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
  *	2 as published by the Free Software Foundation.
  */

 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/tty.h>
 #include <linux/tty_driver.h>
 #include <linux/tty_flip.h>
 #include <linux/module.h>
 #include <linux/usb.h>
 #include <linux/usb/serial.h>
 #include <linux/uaccess.h>

 static int debug;

 static struct usb_device_id id_table[] = {
 	{ USB_DEVICE(0x05e0, 0x0600) },
 	{ },
 };
 MODULE_DEVICE_TABLE(usb, id_table);

 /* This structure holds all of the individual device information */
 struct symbol_private {
 	struct usb_device *udev;
 	struct usb_serial *serial;
 	struct usb_serial_port *port;
 	unsigned char *int_buffer;
 	struct urb *int_urb;
 	int buffer_size;
 	u8 bInterval;
 	u8 int_address;
 	spinlock_t lock;	/* protects the following flags */
 	bool throttled;
 	bool actually_throttled;
 	bool rts;
 };

 static void symbol_int_callback(struct urb *urb)
 {
 	struct symbol_private *priv = urb->context;
 	unsigned char *data = urb->transfer_buffer;
 	struct usb_serial_port *port = priv->port;
 	int status = urb->status;
 	struct tty_struct *tty;
 	int result;
 	int available_room = 0;
 	int data_length;

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

 	switch (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",
 		    __func__, status);
 		return;
 	default:
 		dbg("%s - nonzero urb status received: %d",
 		    __func__, status);
 		goto exit;
 	}

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

 	if (urb->actual_length > 1) {
 		data_length = urb->actual_length - 1;

 		/*
 		 * Data from the device comes with a 1 byte header:
 		 *
 		 * <size of data>data...
 		 * 	This is real data to be sent to the tty layer
 		 * we pretty much just ignore the size and send everything
 		 * else to the tty layer.
 		 */
 		tty = tty_port_tty_get(&port->port);
 		if (tty) {
 			available_room = tty_buffer_request_room(tty,
 							data_length);
 			if (available_room) {
 				tty_insert_flip_string(tty, &data[1],
 						       available_room);
 				tty_flip_buffer_push(tty);
 			}
 			tty_kref_put(tty);
 		}
 	} else {
 		dev_dbg(&priv->udev->dev,
 			"Improper ammount of data received from the device, "
 			"%d bytes", urb->actual_length);
 	}

 exit:
 	spin_lock(&priv->lock);

 	/* Continue trying to always read if we should */
 	if (!priv->throttled) {
 		usb_fill_int_urb(priv->int_urb, priv->udev,
 				 usb_rcvintpipe(priv->udev,
 				 		priv->int_address),
 				 priv->int_buffer, priv->buffer_size,
 				 symbol_int_callback, priv, priv->bInterval);
 		result = usb_submit_urb(priv->int_urb, GFP_ATOMIC);
 		if (result)
 			dev_err(&port->dev,
 			    "%s - failed resubmitting read urb, error %d\n",
 							__func__, result);
 	} else
 		priv->actually_throttled = true;
 	spin_unlock(&priv->lock);
 }

 static int symbol_open(struct tty_struct *tty, struct usb_serial_port *port)
 {
 	struct symbol_private *priv = usb_get_serial_data(port->serial);
 	unsigned long flags;
 	int result = 0;

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

 	spin_lock_irqsave(&priv->lock, flags);
 	priv->throttled = false;
 	priv->actually_throttled = false;
 	priv->port = port;
 	spin_unlock_irqrestore(&priv->lock, flags);

 	/* Start reading from the device */
 	usb_fill_int_urb(priv->int_urb, priv->udev,
 			 usb_rcvintpipe(priv->udev, priv->int_address),
 			 priv->int_buffer, priv->buffer_size,
 			 symbol_int_callback, priv, priv->bInterval);
 	result = usb_submit_urb(priv->int_urb, GFP_KERNEL);
 	if (result)
 		dev_err(&port->dev,
 			"%s - failed resubmitting read urb, error %d\n",
 			__func__, result);
 	return result;
 }

 static void symbol_close(struct usb_serial_port *port)
 {
 	struct symbol_private *priv = usb_get_serial_data(port->serial);

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

 	/* shutdown our urbs */
 	usb_kill_urb(priv->int_urb);
 }

 static void symbol_throttle(struct tty_struct *tty)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	struct symbol_private *priv = usb_get_serial_data(port->serial);

 	dbg("%s - port %d", __func__, port->number);
 	spin_lock_irq(&priv->lock);
 	priv->throttled = true;
 	spin_unlock_irq(&priv->lock);
 }

 static void symbol_unthrottle(struct tty_struct *tty)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	struct symbol_private *priv = usb_get_serial_data(port->serial);
 	int result;
 	bool was_throttled;

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

 	spin_lock_irq(&priv->lock);
 	priv->throttled = false;
 	was_throttled = priv->actually_throttled;
 	priv->actually_throttled = false;
 	spin_unlock_irq(&priv->lock);

 	priv->int_urb->dev = port->serial->dev;
 	if (was_throttled) {
 		result = usb_submit_urb(priv->int_urb, GFP_KERNEL);
 		if (result)
 			dev_err(&port->dev,
 				"%s - failed submitting read urb, error %d\n",
 							__func__, result);
 	}
 }

 static int symbol_startup(struct usb_serial *serial)
 {
 	struct symbol_private *priv;
 	struct usb_host_interface *intf;
 	int i;
 	int retval = -ENOMEM;
 	bool int_in_found = false;

 	/* create our private serial structure */
 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 	if (priv == NULL) {
 		dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
 		return -ENOMEM;
 	}
 	spin_lock_init(&priv->lock);
 	priv->serial = serial;
 	priv->port = serial->port[0];
 	priv->udev = serial->dev;

 	/* find our interrupt endpoint */
 	intf = serial->interface->altsetting;
 	for (i = 0; i < intf->desc.bNumEndpoints; ++i) {
 		struct usb_endpoint_descriptor *endpoint;

 		endpoint = &intf->endpoint[i].desc;
 		if (!usb_endpoint_is_int_in(endpoint))
 			continue;

 		priv->int_urb = usb_alloc_urb(0, GFP_KERNEL);
 		if (!priv->int_urb) {
 			dev_err(&priv->udev->dev, "out of memory\n");
 			goto error;
 		}

 		priv->buffer_size = le16_to_cpu(endpoint->wMaxPacketSize) * 2;
 		priv->int_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
 		if (!priv->int_buffer) {
 			dev_err(&priv->udev->dev, "out of memory\n");
 			goto error;
 		}

 		priv->int_address = endpoint->bEndpointAddress;
 		priv->bInterval = endpoint->bInterval;

 		/* set up our int urb */
 		usb_fill_int_urb(priv->int_urb, priv->udev,
 				 usb_rcvintpipe(priv->udev,
 				 		endpoint->bEndpointAddress),
 				 priv->int_buffer, priv->buffer_size,
 				 symbol_int_callback, priv, priv->bInterval);

 		int_in_found = true;
 		break;
 		}

 	if (!int_in_found) {
 		dev_err(&priv->udev->dev,
 			"Error - the proper endpoints were not found!\n");
 		goto error;
 	}

 	usb_set_serial_data(serial, priv);
 	return 0;

 error:
 	usb_free_urb(priv->int_urb);
 	kfree(priv->int_buffer);
 	kfree(priv);
 	return retval;
 }

 static void symbol_disconnect(struct usb_serial *serial)
 {
 	struct symbol_private *priv = usb_get_serial_data(serial);

 	dbg("%s", __func__);

 	usb_kill_urb(priv->int_urb);
 	usb_free_urb(priv->int_urb);
 }

 static void symbol_release(struct usb_serial *serial)
 {
 	struct symbol_private *priv = usb_get_serial_data(serial);

 	dbg("%s", __func__);

 	kfree(priv->int_buffer);
 	kfree(priv);
 }

 static struct usb_driver symbol_driver = {
 	.name =			"symbol",
 	.probe =		usb_serial_probe,
 	.disconnect =		usb_serial_disconnect,
 	.id_table =		id_table,
 	.no_dynamic_id = 	1,
 };

 static struct usb_serial_driver symbol_device = {
 	.driver = {
 		.owner =	THIS_MODULE,
 		.name =		"symbol",
 	},
 	.id_table =		id_table,
 	.usb_driver = 		&symbol_driver,
 	.num_ports =		1,
 	.attach =		symbol_startup,
 	.open =			symbol_open,
 	.close =		symbol_close,
 	.disconnect =		symbol_disconnect,
 	.release =		symbol_release,
 	.throttle = 		symbol_throttle,
 	.unthrottle =		symbol_unthrottle,
 };

 static int __init symbol_init(void)
 {
 	int retval;

 	retval = usb_serial_register(&symbol_device);
 	if (retval)
 		return retval;
 	retval = usb_register(&symbol_driver);
 	if (retval)
 		usb_serial_deregister(&symbol_device);
 	return retval;
 }

 static void __exit symbol_exit(void)
 {
 	usb_deregister(&symbol_driver);
 	usb_serial_deregister(&symbol_device);
 }

 module_init(symbol_init);
 module_exit(symbol_exit);
 MODULE_LICENSE("GPL");

 module_param(debug, bool, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(debug, "Debug enabled or not");
	/*
	* Symbol USB barcode to serial driver
	*
	* Copyright (C) 2009 Greg Kroah-Hartman <gregkh@suse.de>
	* Copyright (C) 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
	* 2 as published by the Free Software Foundation.
	*/

	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/tty.h>
	#include <linux/tty_driver.h>
	#include <linux/tty_flip.h>
	#include <linux/module.h>
	#include <linux/usb.h>
	#include <linux/usb/serial.h>
	#include <linux/uaccess.h>

	static int debug;

	static struct usb_device_id id_table[] = {
	{ USB_DEVICE(0x05e0, 0x0600) },
	{ },
	};
	MODULE_DEVICE_TABLE(usb, id_table);

	/* This structure holds all of the individual device information */
	struct symbol_private {
	struct usb_device *udev;
	struct usb_serial *serial;
	struct usb_serial_port *port;
	unsigned char *int_buffer;
	struct urb *int_urb;
	int buffer_size;
	u8 bInterval;
	u8 int_address;
	spinlock_t lock; /* protects the following flags */
	bool throttled;
	bool actually_throttled;
	bool rts;
	};

	static void symbol_int_callback(struct urb *urb)
	{
	struct symbol_private *priv = urb->context;
	unsigned char *data = urb->transfer_buffer;
	struct usb_serial_port *port = priv->port;
	int status = urb->status;
	struct tty_struct *tty;
	int result;
	int available_room = 0;
	int data_length;

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

	switch (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",
	__func__, status);
	return;
	default:
	dbg("%s - nonzero urb status received: %d",
	__func__, status);
	goto exit;
	}

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

	if (urb->actual_length > 1) {
	data_length = urb->actual_length - 1;

	/*
	* Data from the device comes with a 1 byte header:
	*
	* <size of data>data...
	* This is real data to be sent to the tty layer
	* we pretty much just ignore the size and send everything
	* else to the tty layer.
	*/
	tty = tty_port_tty_get(&port->port);
	if (tty) {
	available_room = tty_buffer_request_room(tty,
	data_length);
	if (available_room) {
	tty_insert_flip_string(tty, &data[1],
	available_room);
	tty_flip_buffer_push(tty);
	}
	tty_kref_put(tty);
	}
	} else {
	dev_dbg(&priv->udev->dev,
	"Improper ammount of data received from the device, "
	"%d bytes", urb->actual_length);
	}

	exit:
	spin_lock(&priv->lock);

	/* Continue trying to always read if we should */
	if (!priv->throttled) {
	usb_fill_int_urb(priv->int_urb, priv->udev,
	usb_rcvintpipe(priv->udev,
	priv->int_address),
	priv->int_buffer, priv->buffer_size,
	symbol_int_callback, priv, priv->bInterval);
	result = usb_submit_urb(priv->int_urb, GFP_ATOMIC);
	if (result)
	dev_err(&port->dev,
	"%s - failed resubmitting read urb, error %d\n",
	__func__, result);
	} else
	priv->actually_throttled = true;
	spin_unlock(&priv->lock);
	}

	static int symbol_open(struct tty_struct tty, struct usb_serial_port port)
	{
	struct symbol_private *priv = usb_get_serial_data(port->serial);
	unsigned long flags;
	int result = 0;

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

	spin_lock_irqsave(&priv->lock, flags);
	priv->throttled = false;
	priv->actually_throttled = false;
	priv->port = port;
	spin_unlock_irqrestore(&priv->lock, flags);

	/* Start reading from the device */
	usb_fill_int_urb(priv->int_urb, priv->udev,
	usb_rcvintpipe(priv->udev, priv->int_address),
	priv->int_buffer, priv->buffer_size,
	symbol_int_callback, priv, priv->bInterval);
	result = usb_submit_urb(priv->int_urb, GFP_KERNEL);
	if (result)
	dev_err(&port->dev,
	"%s - failed resubmitting read urb, error %d\n",
	__func__, result);
	return result;
	}

	static void symbol_close(struct usb_serial_port *port)
	{
	struct symbol_private *priv = usb_get_serial_data(port->serial);

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

	/* shutdown our urbs */
	usb_kill_urb(priv->int_urb);
	}

	static void symbol_throttle(struct tty_struct *tty)
	{
	struct usb_serial_port *port = tty->driver_data;
	struct symbol_private *priv = usb_get_serial_data(port->serial);

	dbg("%s - port %d", __func__, port->number);
	spin_lock_irq(&priv->lock);
	priv->throttled = true;
	spin_unlock_irq(&priv->lock);
	}

	static void symbol_unthrottle(struct tty_struct *tty)
	{
	struct usb_serial_port *port = tty->driver_data;
	struct symbol_private *priv = usb_get_serial_data(port->serial);
	int result;
	bool was_throttled;

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

	spin_lock_irq(&priv->lock);
	priv->throttled = false;
	was_throttled = priv->actually_throttled;
	priv->actually_throttled = false;
	spin_unlock_irq(&priv->lock);

	priv->int_urb->dev = port->serial->dev;
	if (was_throttled) {
	result = usb_submit_urb(priv->int_urb, GFP_KERNEL);
	if (result)
	dev_err(&port->dev,
	"%s - failed submitting read urb, error %d\n",
	__func__, result);
	}
	}

	static int symbol_startup(struct usb_serial *serial)
	{
	struct symbol_private *priv;
	struct usb_host_interface *intf;
	int i;
	int retval = -ENOMEM;
	bool int_in_found = false;

	/* create our private serial structure */
	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (priv == NULL) {
	dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
	return -ENOMEM;
	}
	spin_lock_init(&priv->lock);
	priv->serial = serial;
	priv->port = serial->port[0];
	priv->udev = serial->dev;

	/* find our interrupt endpoint */
	intf = serial->interface->altsetting;
	for (i = 0; i < intf->desc.bNumEndpoints; ++i) {
	struct usb_endpoint_descriptor *endpoint;

	endpoint = &intf->endpoint[i].desc;
	if (!usb_endpoint_is_int_in(endpoint))
	continue;

	priv->int_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!priv->int_urb) {
	dev_err(&priv->udev->dev, "out of memory\n");
	goto error;
	}

	priv->buffer_size = le16_to_cpu(endpoint->wMaxPacketSize) * 2;
	priv->int_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
	if (!priv->int_buffer) {
	dev_err(&priv->udev->dev, "out of memory\n");
	goto error;
	}

	priv->int_address = endpoint->bEndpointAddress;
	priv->bInterval = endpoint->bInterval;

	/* set up our int urb */
	usb_fill_int_urb(priv->int_urb, priv->udev,
	usb_rcvintpipe(priv->udev,
	endpoint->bEndpointAddress),
	priv->int_buffer, priv->buffer_size,
	symbol_int_callback, priv, priv->bInterval);

	int_in_found = true;
	break;
	}

	if (!int_in_found) {
	dev_err(&priv->udev->dev,
	"Error - the proper endpoints were not found!\n");
	goto error;
	}

	usb_set_serial_data(serial, priv);
	return 0;

	error:
	usb_free_urb(priv->int_urb);
	kfree(priv->int_buffer);
	kfree(priv);
	return retval;
	}

	static void symbol_disconnect(struct usb_serial *serial)
	{
	struct symbol_private *priv = usb_get_serial_data(serial);

	dbg("%s", __func__);

	usb_kill_urb(priv->int_urb);
	usb_free_urb(priv->int_urb);
	}

	static void symbol_release(struct usb_serial *serial)
	{
	struct symbol_private *priv = usb_get_serial_data(serial);

	dbg("%s", __func__);

	kfree(priv->int_buffer);
	kfree(priv);
	}

	static struct usb_driver symbol_driver = {
	.name = "symbol",
	.probe = usb_serial_probe,
	.disconnect = usb_serial_disconnect,
	.id_table = id_table,
	.no_dynamic_id = 1,
	};

	static struct usb_serial_driver symbol_device = {
	.driver = {
	.owner = THIS_MODULE,
	.name = "symbol",
	},
	.id_table = id_table,
	.usb_driver = &symbol_driver,
	.num_ports = 1,
	.attach = symbol_startup,
	.open = symbol_open,
	.close = symbol_close,
	.disconnect = symbol_disconnect,
	.release = symbol_release,
	.throttle = symbol_throttle,
	.unthrottle = symbol_unthrottle,
	};

	static int __init symbol_init(void)
	{
	int retval;

	retval = usb_serial_register(&symbol_device);
	if (retval)
	return retval;
	retval = usb_register(&symbol_driver);
	if (retval)
	usb_serial_deregister(&symbol_device);
	return retval;
	}

	static void __exit symbol_exit(void)
	{
	usb_deregister(&symbol_driver);
	usb_serial_deregister(&symbol_device);
	}

	module_init(symbol_init);
	module_exit(symbol_exit);
	MODULE_LICENSE("GPL");

	module_param(debug, bool, S_IRUGO \| S_IWUSR);
	MODULE_PARM_DESC(debug, "Debug enabled or not");