[deliverable/linux.git] / drivers / usb / serial / generic.c

/*
 * USB Serial Converter Generic functions
 *
 * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com)
 *
 *	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/errno.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <asm/uaccess.h>


static int debug;

#ifdef CONFIG_USB_SERIAL_GENERIC

static int generic_probe(struct usb_interface *interface,
			 const struct usb_device_id *id);

static __u16 vendor  = 0x05f9;
static __u16 product = 0xffff;

module_param(vendor, ushort, 0);
MODULE_PARM_DESC(vendor, "User specified USB idVendor");

module_param(product, ushort, 0);
MODULE_PARM_DESC(product, "User specified USB idProduct");

static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */

/* we want to look at all devices, as the vendor/product id can change
 * depending on the command line argument */
static struct usb_device_id generic_serial_ids[] = {
	{.driver_info = 42},
	{}
};

static struct usb_driver generic_driver = {
	.name =		"usbserial_generic",
	.probe =	generic_probe,
	.disconnect =	usb_serial_disconnect,
	.id_table =	generic_serial_ids,
	.no_dynamic_id =	1,
};

/* All of the device info needed for the Generic Serial Converter */
struct usb_serial_driver usb_serial_generic_device = {
	.driver = {
		.owner =	THIS_MODULE,
		.name =		"generic",
	},
	.id_table =		generic_device_ids,
	.usb_driver = 		&generic_driver,
	.num_interrupt_in =	NUM_DONT_CARE,
	.num_bulk_in =		NUM_DONT_CARE,
	.num_bulk_out =		NUM_DONT_CARE,
	.num_ports =		1,
	.shutdown =		usb_serial_generic_shutdown,
	.throttle =		usb_serial_generic_throttle,
	.unthrottle =		usb_serial_generic_unthrottle,
};

static int generic_probe(struct usb_interface *interface,
			       const struct usb_device_id *id)
{
	const struct usb_device_id *id_pattern;

	id_pattern = usb_match_id(interface, generic_device_ids);
	if (id_pattern != NULL)
		return usb_serial_probe(interface, id);
	return -ENODEV;
}
#endif

int usb_serial_generic_register (int _debug)
{
	int retval = 0;

	debug = _debug;
#ifdef CONFIG_USB_SERIAL_GENERIC
	generic_device_ids[0].idVendor = vendor;
	generic_device_ids[0].idProduct = product;
	generic_device_ids[0].match_flags = USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;

	/* register our generic driver with ourselves */
	retval = usb_serial_register (&usb_serial_generic_device);
	if (retval)
		goto exit;
	retval = usb_register(&generic_driver);
	if (retval)
		usb_serial_deregister(&usb_serial_generic_device);
exit:
#endif
	return retval;
}

void usb_serial_generic_deregister (void)
{
#ifdef CONFIG_USB_SERIAL_GENERIC
	/* remove our generic driver */
	usb_deregister(&generic_driver);
	usb_serial_deregister (&usb_serial_generic_device);
#endif
}

int usb_serial_generic_open (struct usb_serial_port *port, struct file *filp)
{
	struct usb_serial *serial = port->serial;
	int result = 0;
	unsigned long flags;

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

	/* force low_latency on so that our tty_push actually forces the data through, 
	   otherwise it is scheduled, and with high data rates (like with OHCI) data
	   can get lost. */
	if (port->tty)
		port->tty->low_latency = 1;

	/* clear the throttle flags */
	spin_lock_irqsave(&port->lock, flags);
	port->throttled = 0;
	port->throttle_req = 0;
	spin_unlock_irqrestore(&port->lock, flags);

	/* if we have a bulk endpoint, start reading from it */
	if (serial->num_bulk_in) {
		/* Start reading from the device */
		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,
				   ((serial->type->read_bulk_callback) ?
				     serial->type->read_bulk_callback :
				     usb_serial_generic_read_bulk_callback),
				   port);
		result = usb_submit_urb(port->read_urb, GFP_KERNEL);
		if (result)
			dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
	}

	return result;
}
EXPORT_SYMBOL_GPL(usb_serial_generic_open);

static void generic_cleanup (struct usb_serial_port *port)
{
	struct usb_serial *serial = port->serial;

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

	if (serial->dev) {
		/* shutdown any bulk reads that might be going on */
		if (serial->num_bulk_out)
			usb_kill_urb(port->write_urb);
		if (serial->num_bulk_in)
			usb_kill_urb(port->read_urb);
	}
}

void usb_serial_generic_close (struct usb_serial_port *port, struct file * filp)
{
	dbg("%s - port %d", __FUNCTION__, port->number);
	generic_cleanup (port);
}

int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char *buf, int count)
{
	struct usb_serial *serial = port->serial;
	int result;
	unsigned char *data;

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

	if (count == 0) {
		dbg("%s - write request of 0 bytes", __FUNCTION__);
		return (0);
	}

	/* only do something if we have a bulk out endpoint */
	if (serial->num_bulk_out) {
		spin_lock_bh(&port->lock);
		if (port->write_urb_busy) {
			spin_unlock_bh(&port->lock);
			dbg("%s - already writing", __FUNCTION__);
			return 0;
		}
		port->write_urb_busy = 1;
		spin_unlock_bh(&port->lock);

		count = (count > port->bulk_out_size) ? port->bulk_out_size : count;

		memcpy (port->write_urb->transfer_buffer, buf, count);
		data = port->write_urb->transfer_buffer;
		usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, data);

		/* set up our urb */
		usb_fill_bulk_urb (port->write_urb, serial->dev,
				   usb_sndbulkpipe (serial->dev,
						    port->bulk_out_endpointAddress),
				   port->write_urb->transfer_buffer, count,
				   ((serial->type->write_bulk_callback) ? 
				     serial->type->write_bulk_callback :
				     usb_serial_generic_write_bulk_callback), port);

		/* send the data out the bulk port */
		port->write_urb_busy = 1;
		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
		if (result) {
			dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
			/* don't have to grab the lock here, as we will retry if != 0 */
			port->write_urb_busy = 0;
		} else
			result = count;

		return result;
	}

	/* no bulk out, so return 0 bytes written */
	return 0;
}

int usb_serial_generic_write_room (struct usb_serial_port *port)
{
	struct usb_serial *serial = port->serial;
	int room = 0;

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

	if (serial->num_bulk_out) {
		if (!(port->write_urb_busy))
			room = port->bulk_out_size;
	}

	dbg("%s - returns %d", __FUNCTION__, room);
	return (room);
}

int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port)
{
	struct usb_serial *serial = port->serial;
	int chars = 0;

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

	if (serial->num_bulk_out) {
		if (port->write_urb_busy)
			chars = port->write_urb->transfer_buffer_length;
	}

	dbg("%s - returns %d", __FUNCTION__, chars);
	return (chars);
}

/* Push data to tty layer and resubmit the bulk read URB */
static void flush_and_resubmit_read_urb (struct usb_serial_port *port)
{
	struct usb_serial *serial = port->serial;
	struct urb *urb = port->read_urb;
	struct tty_struct *tty = port->tty;
	int result;

	/* Push data to tty */
	if (tty && urb->actual_length) {
		tty_buffer_request_room(tty, urb->actual_length);
		tty_insert_flip_string(tty, urb->transfer_buffer, urb->actual_length);
	  	tty_flip_buffer_push(tty); /* is this allowed from an URB callback ? */
	}

	/* Continue reading from device */
	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,
			   ((serial->type->read_bulk_callback) ? 
			     serial->type->read_bulk_callback : 
			     usb_serial_generic_read_bulk_callback), port);
	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
	if (result)
		dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
}

void usb_serial_generic_read_bulk_callback (struct urb *urb)
{
	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
	unsigned char *data = urb->transfer_buffer;
	int is_throttled;
	unsigned long flags;

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

	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);

	/* Throttle the device if requested by tty */
	if (urb->actual_length) {
		spin_lock_irqsave(&port->lock, flags);
		is_throttled = port->throttled = port->throttle_req;
		spin_unlock_irqrestore(&port->lock, flags);
		if (is_throttled) {
			/* Let the received data linger in the read URB;
			 * usb_serial_generic_unthrottle() will pick it
			 * up later. */
			dbg("%s - throttling device", __FUNCTION__);
			return;
		}
	}

	/* Handle data and continue reading from device */
	flush_and_resubmit_read_urb(port);
}
EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);

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

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

	port->write_urb_busy = 0;
	if (urb->status) {
		dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
		return;
	}

	usb_serial_port_softint(port);
}
EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);

void usb_serial_generic_throttle (struct usb_serial_port *port)
{
	unsigned long flags;

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

	/* Set the throttle request flag. It will be picked up
	 * by usb_serial_generic_read_bulk_callback(). */
	spin_lock_irqsave(&port->lock, flags);
	port->throttle_req = 1;
	spin_unlock_irqrestore(&port->lock, flags);
}

void usb_serial_generic_unthrottle (struct usb_serial_port *port)
{
	int was_throttled;
	unsigned long flags;

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

	/* Clear the throttle flags */
	spin_lock_irqsave(&port->lock, flags);
	was_throttled = port->throttled;
	port->throttled = port->throttle_req = 0;
	spin_unlock_irqrestore(&port->lock, flags);

	if (was_throttled) {
		/* Handle pending data and resume reading from device */
		flush_and_resubmit_read_urb(port);
	}
}

void usb_serial_generic_shutdown (struct usb_serial *serial)
{
	int i;

	dbg("%s", __FUNCTION__);

	/* stop reads and writes on all ports */
	for (i=0; i < serial->num_ports; ++i) {
		generic_cleanup(serial->port[i]);
	}
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* USB Serial Converter Generic functions
	3	*
	4	* Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com)
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License version
	8	* 2 as published by the Free Software Foundation.
	9	*
	10	*/
	11
1da177e4 LT	12	#include <linux/kernel.h>
	13	#include <linux/errno.h>
	14	#include <linux/slab.h>
	15	#include <linux/tty.h>
	16	#include <linux/tty_flip.h>
	17	#include <linux/module.h>
	18	#include <linux/moduleparam.h>
	19	#include <linux/usb.h>
a969888c	20	#include <linux/usb/serial.h>
1da177e4	21	#include <asm/uaccess.h>
1da177e4	22
d9b1b787	23
1da177e4 LT	24	static int debug;
	25
	26	#ifdef CONFIG_USB_SERIAL_GENERIC
b46d60fc DB	27
	28	static int generic_probe(struct usb_interface *interface,
	29	const struct usb_device_id *id);
	30
1da177e4 LT	31	static __u16 vendor = 0x05f9;
	32	static __u16 product = 0xffff;
	33
	34	module_param(vendor, ushort, 0);
	35	MODULE_PARM_DESC(vendor, "User specified USB idVendor");
	36
	37	module_param(product, ushort, 0);
	38	MODULE_PARM_DESC(product, "User specified USB idProduct");
	39
	40	static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
	41
d9b1b787 JH	42	/* we want to look at all devices, as the vendor/product id can change
	43	* depending on the command line argument */
	44	static struct usb_device_id generic_serial_ids[] = {
	45	{.driver_info = 42},
	46	{}
	47	};
	48
	49	static struct usb_driver generic_driver = {
	50	.name = "usbserial_generic",
	51	.probe = generic_probe,
	52	.disconnect = usb_serial_disconnect,
	53	.id_table = generic_serial_ids,
	54	.no_dynamic_id = 1,
	55	};
	56
1da177e4	57	/* All of the device info needed for the Generic Serial Converter */
ea65370d	58	struct usb_serial_driver usb_serial_generic_device = {
18fcac35 GKH	59	.driver = {
18fcac35 GKH	60	.owner = THIS_MODULE,
269bda1c	61	.name = "generic",
18fcac35	62	},
1da177e4	63	.id_table = generic_device_ids,
d9b1b787	64	.usb_driver = &generic_driver,
1da177e4 LT	65	.num_interrupt_in = NUM_DONT_CARE,
	66	.num_bulk_in = NUM_DONT_CARE,
	67	.num_bulk_out = NUM_DONT_CARE,
	68	.num_ports = 1,
	69	.shutdown = usb_serial_generic_shutdown,
253ca923 JR	70	.throttle = usb_serial_generic_throttle,
253ca923 JR	71	.unthrottle = usb_serial_generic_unthrottle,
1da177e4 LT	72	};
1da177e4 LT	73
1da177e4 LT	74	static int generic_probe(struct usb_interface *interface,
	75	const struct usb_device_id *id)
	76	{
	77	const struct usb_device_id *id_pattern;
	78
	79	id_pattern = usb_match_id(interface, generic_device_ids);
	80	if (id_pattern != NULL)
	81	return usb_serial_probe(interface, id);
	82	return -ENODEV;
	83	}
1da177e4 LT	84	#endif
	85
	86	int usb_serial_generic_register (int _debug)
	87	{
	88	int retval = 0;
	89
	90	debug = _debug;
	91	#ifdef CONFIG_USB_SERIAL_GENERIC
	92	generic_device_ids[0].idVendor = vendor;
	93	generic_device_ids[0].idProduct = product;
	94	generic_device_ids[0].match_flags = USB_DEVICE_ID_MATCH_VENDOR \| USB_DEVICE_ID_MATCH_PRODUCT;
	95
	96	/* register our generic driver with ourselves */
	97	retval = usb_serial_register (&usb_serial_generic_device);
	98	if (retval)
	99	goto exit;
	100	retval = usb_register(&generic_driver);
	101	if (retval)
	102	usb_serial_deregister(&usb_serial_generic_device);
	103	exit:
	104	#endif
	105	return retval;
	106	}
	107
	108	void usb_serial_generic_deregister (void)
	109	{
	110	#ifdef CONFIG_USB_SERIAL_GENERIC
	111	/* remove our generic driver */
	112	usb_deregister(&generic_driver);
	113	usb_serial_deregister (&usb_serial_generic_device);
	114	#endif
	115	}
	116
	117	int usb_serial_generic_open (struct usb_serial_port port, struct file filp)
	118	{
	119	struct usb_serial *serial = port->serial;
	120	int result = 0;
253ca923	121	unsigned long flags;
1da177e4 LT	122
	123	dbg("%s - port %d", __FUNCTION__, port->number);
	124
	125	/* force low_latency on so that our tty_push actually forces the data through,
	126	otherwise it is scheduled, and with high data rates (like with OHCI) data
	127	can get lost. */
	128	if (port->tty)
	129	port->tty->low_latency = 1;
	130
253ca923 JR	131	/* clear the throttle flags */
	132	spin_lock_irqsave(&port->lock, flags);
	133	port->throttled = 0;
	134	port->throttle_req = 0;
	135	spin_unlock_irqrestore(&port->lock, flags);
	136
	137	/* if we have a bulk endpoint, start reading from it */
1da177e4 LT	138	if (serial->num_bulk_in) {
	139	/* Start reading from the device */
	140	usb_fill_bulk_urb (port->read_urb, serial->dev,
	141	usb_rcvbulkpipe(serial->dev, port->bulk_in_endpointAddress),
	142	port->read_urb->transfer_buffer,
	143	port->read_urb->transfer_buffer_length,
	144	((serial->type->read_bulk_callback) ?
	145	serial->type->read_bulk_callback :
	146	usb_serial_generic_read_bulk_callback),
	147	port);
	148	result = usb_submit_urb(port->read_urb, GFP_KERNEL);
	149	if (result)
	150	dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
	151	}
	152
	153	return result;
	154	}
815ddc99	155	EXPORT_SYMBOL_GPL(usb_serial_generic_open);
1da177e4 LT	156
	157	static void generic_cleanup (struct usb_serial_port *port)
	158	{
	159	struct usb_serial *serial = port->serial;
	160
	161	dbg("%s - port %d", __FUNCTION__, port->number);
	162
	163	if (serial->dev) {
	164	/* shutdown any bulk reads that might be going on */
	165	if (serial->num_bulk_out)
	166	usb_kill_urb(port->write_urb);
	167	if (serial->num_bulk_in)
	168	usb_kill_urb(port->read_urb);
	169	}
	170	}
	171
	172	void usb_serial_generic_close (struct usb_serial_port port, struct file filp)
	173	{
	174	dbg("%s - port %d", __FUNCTION__, port->number);
	175	generic_cleanup (port);
	176	}
	177
	178	int usb_serial_generic_write(struct usb_serial_port port, const unsigned char buf, int count)
	179	{
	180	struct usb_serial *serial = port->serial;
	181	int result;
	182	unsigned char *data;
	183
	184	dbg("%s - port %d", __FUNCTION__, port->number);
	185
	186	if (count == 0) {
	187	dbg("%s - write request of 0 bytes", __FUNCTION__);
	188	return (0);
	189	}
	190
	191	/* only do something if we have a bulk out endpoint */
	192	if (serial->num_bulk_out) {
e81ee637	193	spin_lock_bh(&port->lock);
507ca9bc	194	if (port->write_urb_busy) {
e81ee637	195	spin_unlock_bh(&port->lock);
1da177e4	196	dbg("%s - already writing", __FUNCTION__);
507ca9bc	197	return 0;
1da177e4	198	}
507ca9bc	199	port->write_urb_busy = 1;
e81ee637	200	spin_unlock_bh(&port->lock);
1da177e4 LT	201
	202	count = (count > port->bulk_out_size) ? port->bulk_out_size : count;
	203
	204	memcpy (port->write_urb->transfer_buffer, buf, count);
	205	data = port->write_urb->transfer_buffer;
	206	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, data);
	207
	208	/* set up our urb */
	209	usb_fill_bulk_urb (port->write_urb, serial->dev,
	210	usb_sndbulkpipe (serial->dev,
	211	port->bulk_out_endpointAddress),
	212	port->write_urb->transfer_buffer, count,
	213	((serial->type->write_bulk_callback) ?
	214	serial->type->write_bulk_callback :
	215	usb_serial_generic_write_bulk_callback), port);
	216
	217	/* send the data out the bulk port */
507ca9bc	218	port->write_urb_busy = 1;
1da177e4	219	result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
507ca9bc	220	if (result) {
1da177e4	221	dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
507ca9bc GKH	222	/* don't have to grab the lock here, as we will retry if != 0 */
	223	port->write_urb_busy = 0;
	224	} else
1da177e4 LT	225	result = count;
	226
	227	return result;
	228	}
	229
	230	/* no bulk out, so return 0 bytes written */
507ca9bc	231	return 0;
1da177e4 LT	232	}
	233
	234	int usb_serial_generic_write_room (struct usb_serial_port *port)
	235	{
	236	struct usb_serial *serial = port->serial;
	237	int room = 0;
	238
	239	dbg("%s - port %d", __FUNCTION__, port->number);
507ca9bc	240
1da177e4	241	if (serial->num_bulk_out) {
7a3ca7d2	242	if (!(port->write_urb_busy))
1da177e4 LT	243	room = port->bulk_out_size;
	244	}
	245
	246	dbg("%s - returns %d", __FUNCTION__, room);
	247	return (room);
	248	}
	249
	250	int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port)
	251	{
	252	struct usb_serial *serial = port->serial;
	253	int chars = 0;
	254
	255	dbg("%s - port %d", __FUNCTION__, port->number);
	256
	257	if (serial->num_bulk_out) {
507ca9bc	258	if (port->write_urb_busy)
1da177e4 LT	259	chars = port->write_urb->transfer_buffer_length;
	260	}
	261
	262	dbg("%s - returns %d", __FUNCTION__, chars);
	263	return (chars);
	264	}
	265
253ca923 JR	266	/* Push data to tty layer and resubmit the bulk read URB */
253ca923 JR	267	static void flush_and_resubmit_read_urb (struct usb_serial_port *port)
1da177e4	268	{
1da177e4	269	struct usb_serial *serial = port->serial;
253ca923 JR	270	struct urb *urb = port->read_urb;
253ca923 JR	271	struct tty_struct *tty = port->tty;
1da177e4 LT	272	int result;
1da177e4 LT	273
253ca923	274	/* Push data to tty */
1da177e4	275	if (tty && urb->actual_length) {
33f0f88f	276	tty_buffer_request_room(tty, urb->actual_length);
253ca923 JR	277	tty_insert_flip_string(tty, urb->transfer_buffer, urb->actual_length);
253ca923 JR	278	tty_flip_buffer_push(tty); /* is this allowed from an URB callback ? */
1da177e4 LT	279	}
1da177e4 LT	280
253ca923	281	/* Continue reading from device */
1da177e4 LT	282	usb_fill_bulk_urb (port->read_urb, serial->dev,
	283	usb_rcvbulkpipe (serial->dev,
	284	port->bulk_in_endpointAddress),
	285	port->read_urb->transfer_buffer,
	286	port->read_urb->transfer_buffer_length,
	287	((serial->type->read_bulk_callback) ?
	288	serial->type->read_bulk_callback :
	289	usb_serial_generic_read_bulk_callback), port);
	290	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
	291	if (result)
	292	dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
	293	}
253ca923 JR	294
	295	void usb_serial_generic_read_bulk_callback (struct urb *urb)
	296	{
	297	struct usb_serial_port port = (struct usb_serial_port )urb->context;
	298	unsigned char *data = urb->transfer_buffer;
	299	int is_throttled;
	300	unsigned long flags;
	301
	302	dbg("%s - port %d", __FUNCTION__, port->number);
	303
	304	if (urb->status) {
	305	dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
	306	return;
	307	}
	308
	309	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
	310
	311	/* Throttle the device if requested by tty */
	312	if (urb->actual_length) {
	313	spin_lock_irqsave(&port->lock, flags);
	314	is_throttled = port->throttled = port->throttle_req;
	315	spin_unlock_irqrestore(&port->lock, flags);
	316	if (is_throttled) {
	317	/* Let the received data linger in the read URB;
	318	* usb_serial_generic_unthrottle() will pick it
	319	* up later. */
	320	dbg("%s - throttling device", __FUNCTION__);
	321	return;
	322	}
	323	}
	324
	325	/* Handle data and continue reading from device */
	326	flush_and_resubmit_read_urb(port);
	327	}
166ffccf	328	EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
1da177e4	329
7d12e780	330	void usb_serial_generic_write_bulk_callback (struct urb *urb)
1da177e4 LT	331	{
	332	struct usb_serial_port port = (struct usb_serial_port )urb->context;
	333
	334	dbg("%s - port %d", __FUNCTION__, port->number);
	335
507ca9bc	336	port->write_urb_busy = 0;
1da177e4 LT	337	if (urb->status) {
	338	dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
	339	return;
	340	}
	341
cf2c7481	342	usb_serial_port_softint(port);
1da177e4	343	}
bb833986	344	EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
1da177e4	345
253ca923 JR	346	void usb_serial_generic_throttle (struct usb_serial_port *port)
	347	{
	348	unsigned long flags;
	349
	350	dbg("%s - port %d", __FUNCTION__, port->number);
	351
	352	/* Set the throttle request flag. It will be picked up
	353	* by usb_serial_generic_read_bulk_callback(). */
	354	spin_lock_irqsave(&port->lock, flags);
	355	port->throttle_req = 1;
	356	spin_unlock_irqrestore(&port->lock, flags);
	357	}
	358
	359	void usb_serial_generic_unthrottle (struct usb_serial_port *port)
	360	{
	361	int was_throttled;
	362	unsigned long flags;
	363
	364	dbg("%s - port %d", __FUNCTION__, port->number);
	365
	366	/* Clear the throttle flags */
	367	spin_lock_irqsave(&port->lock, flags);
	368	was_throttled = port->throttled;
	369	port->throttled = port->throttle_req = 0;
	370	spin_unlock_irqrestore(&port->lock, flags);
	371
	372	if (was_throttled) {
	373	/* Handle pending data and resume reading from device */
	374	flush_and_resubmit_read_urb(port);
	375	}
	376	}
	377
1da177e4 LT	378	void usb_serial_generic_shutdown (struct usb_serial *serial)
	379	{
	380	int i;
	381
	382	dbg("%s", __FUNCTION__);
	383
	384	/* stop reads and writes on all ports */
	385	for (i=0; i < serial->num_ports; ++i) {
	386	generic_cleanup(serial->port[i]);
	387	}
	388	}
	389