drivers/media/video/gspca/jeilinj.c - maze/linux - Git at Google

 /*
  * Jeilinj subdriver
  *
  * Supports some Jeilin dual-mode cameras which use bulk transport and
  * download raw JPEG data.
  *
  * Copyright (C) 2009 Theodore Kilgore
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */

 #define MODULE_NAME "jeilinj"

 #include <linux/workqueue.h>
 #include <linux/slab.h>
 #include "gspca.h"
 #include "jpeg.h"

 MODULE_AUTHOR("Theodore Kilgore <kilgota@auburn.edu>");
 MODULE_DESCRIPTION("GSPCA/JEILINJ USB Camera Driver");
 MODULE_LICENSE("GPL");

 /* Default timeouts, in ms */
 #define JEILINJ_CMD_TIMEOUT 500
 #define JEILINJ_DATA_TIMEOUT 1000

 /* Maximum transfer size to use. */
 #define JEILINJ_MAX_TRANSFER 0x200

 #define FRAME_HEADER_LEN 0x10

 /* Structure to hold all of our device specific stuff */
 struct sd {
 	struct gspca_dev gspca_dev;	/* !! must be the first item */
 	const struct v4l2_pix_format *cap_mode;
 	/* Driver stuff */
 	struct work_struct work_struct;
 	struct workqueue_struct *work_thread;
 	u8 quality;				 /* image quality */
 	u8 jpegqual;				/* webcam quality */
 	u8 jpeg_hdr[JPEG_HDR_SZ];
 };

 	struct jlj_command {
 		unsigned char instruction[2];
 		unsigned char ack_wanted;
 	};

 /* AFAICT these cameras will only do 320x240. */
 static struct v4l2_pix_format jlj_mode[] = {
 	{ 320, 240, V4L2_PIX_FMT_JPEG, V4L2_FIELD_NONE,
 		.bytesperline = 320,
 		.sizeimage = 320 * 240,
 		.colorspace = V4L2_COLORSPACE_JPEG,
 		.priv = 0}
 };

 /*
  * cam uses endpoint 0x03 to send commands, 0x84 for read commands,
  * and 0x82 for bulk transfer.
  */

 /* All commands are two bytes only */
 static int jlj_write2(struct gspca_dev *gspca_dev, unsigned char *command)
 {
 	int retval;

 	memcpy(gspca_dev->usb_buf, command, 2);
 	retval = usb_bulk_msg(gspca_dev->dev,
 			usb_sndbulkpipe(gspca_dev->dev, 3),
 			gspca_dev->usb_buf, 2, NULL, 500);
 	if (retval < 0)
 		err("command write [%02x] error %d",
 				gspca_dev->usb_buf[0], retval);
 	return retval;
 }

 /* Responses are one byte only */
 static int jlj_read1(struct gspca_dev *gspca_dev, unsigned char response)
 {
 	int retval;

 	retval = usb_bulk_msg(gspca_dev->dev,
 	usb_rcvbulkpipe(gspca_dev->dev, 0x84),
 				gspca_dev->usb_buf, 1, NULL, 500);
 	response = gspca_dev->usb_buf[0];
 	if (retval < 0)
 		err("read command [%02x] error %d",
 				gspca_dev->usb_buf[0], retval);
 	return retval;
 }

 static int jlj_start(struct gspca_dev *gspca_dev)
 {
 	int i;
 	int retval = -1;
 	u8 response = 0xff;
 	struct jlj_command start_commands[] = {
 		{{0x71, 0x81}, 0},
 		{{0x70, 0x05}, 0},
 		{{0x95, 0x70}, 1},
 		{{0x71, 0x81}, 0},
 		{{0x70, 0x04}, 0},
 		{{0x95, 0x70}, 1},
 		{{0x71, 0x00}, 0},
 		{{0x70, 0x08}, 0},
 		{{0x95, 0x70}, 1},
 		{{0x94, 0x02}, 0},
 		{{0xde, 0x24}, 0},
 		{{0x94, 0x02}, 0},
 		{{0xdd, 0xf0}, 0},
 		{{0x94, 0x02}, 0},
 		{{0xe3, 0x2c}, 0},
 		{{0x94, 0x02}, 0},
 		{{0xe4, 0x00}, 0},
 		{{0x94, 0x02}, 0},
 		{{0xe5, 0x00}, 0},
 		{{0x94, 0x02}, 0},
 		{{0xe6, 0x2c}, 0},
 		{{0x94, 0x03}, 0},
 		{{0xaa, 0x00}, 0},
 		{{0x71, 0x1e}, 0},
 		{{0x70, 0x06}, 0},
 		{{0x71, 0x80}, 0},
 		{{0x70, 0x07}, 0}
 	};
 	for (i = 0; i < ARRAY_SIZE(start_commands); i++) {
 		retval = jlj_write2(gspca_dev, start_commands[i].instruction);
 		if (retval < 0)
 			return retval;
 		if (start_commands[i].ack_wanted)
 			retval = jlj_read1(gspca_dev, response);
 		if (retval < 0)
 			return retval;
 	}
 	PDEBUG(D_ERR, "jlj_start retval is %d", retval);
 	return retval;
 }

 static int jlj_stop(struct gspca_dev *gspca_dev)
 {
 	int i;
 	int retval;
 	struct jlj_command stop_commands[] = {
 		{{0x71, 0x00}, 0},
 		{{0x70, 0x09}, 0},
 		{{0x71, 0x80}, 0},
 		{{0x70, 0x05}, 0}
 	};
 	for (i = 0; i < ARRAY_SIZE(stop_commands); i++) {
 		retval = jlj_write2(gspca_dev, stop_commands[i].instruction);
 		if (retval < 0)
 			return retval;
 	}
 	return retval;
 }

 /* This function is called as a workqueue function and runs whenever the camera
  * is streaming data. Because it is a workqueue function it is allowed to sleep
  * so we can use synchronous USB calls. To avoid possible collisions with other
  * threads attempting to use the camera's USB interface the gspca usb_lock is
  * used when performing the one USB control operation inside the workqueue,
  * which tells the camera to close the stream. In practice the only thing
  * which needs to be protected against is the usb_set_interface call that
  * gspca makes during stream_off. Otherwise the camera doesn't provide any
  * controls that the user could try to change.
  */

 static void jlj_dostream(struct work_struct *work)
 {
 	struct sd *dev = container_of(work, struct sd, work_struct);
 	struct gspca_dev *gspca_dev = &dev->gspca_dev;
 	int blocks_left; /* 0x200-sized blocks remaining in current frame. */
 	int act_len;
 	int packet_type;
 	int ret;
 	u8 *buffer;

 	buffer = kmalloc(JEILINJ_MAX_TRANSFER, GFP_KERNEL | GFP_DMA);
 	if (!buffer) {
 		err("Couldn't allocate USB buffer");
 		goto quit_stream;
 	}
 	while (gspca_dev->present && gspca_dev->streaming) {
 		/*
 		 * Now request data block 0. Line 0 reports the size
 		 * to download, in blocks of size 0x200, and also tells the
 		 * "actual" data size, in bytes, which seems best to ignore.
 		 */
 		ret = usb_bulk_msg(gspca_dev->dev,
 				usb_rcvbulkpipe(gspca_dev->dev, 0x82),
 				buffer, JEILINJ_MAX_TRANSFER, &act_len,
 				JEILINJ_DATA_TIMEOUT);
 		PDEBUG(D_STREAM,
 			"Got %d bytes out of %d for Block 0",
 			act_len, JEILINJ_MAX_TRANSFER);
 		if (ret < 0 || act_len < FRAME_HEADER_LEN)
 			goto quit_stream;
 		blocks_left = buffer[0x0a] - 1;
 		PDEBUG(D_STREAM, "blocks_left = 0x%x", blocks_left);

 		/* Start a new frame, and add the JPEG header, first thing */
 		gspca_frame_add(gspca_dev, FIRST_PACKET,
 				dev->jpeg_hdr, JPEG_HDR_SZ);
 		/* Toss line 0 of data block 0, keep the rest. */
 		gspca_frame_add(gspca_dev, INTER_PACKET,
 				buffer + FRAME_HEADER_LEN,
 				JEILINJ_MAX_TRANSFER - FRAME_HEADER_LEN);

 		while (blocks_left > 0) {
 			if (!gspca_dev->present)
 				goto quit_stream;
 			ret = usb_bulk_msg(gspca_dev->dev,
 				usb_rcvbulkpipe(gspca_dev->dev, 0x82),
 				buffer, JEILINJ_MAX_TRANSFER, &act_len,
 				JEILINJ_DATA_TIMEOUT);
 			if (ret < 0 || act_len < JEILINJ_MAX_TRANSFER)
 				goto quit_stream;
 			PDEBUG(D_STREAM,
 				"%d blocks remaining for frame", blocks_left);
 			blocks_left -= 1;
 			if (blocks_left == 0)
 				packet_type = LAST_PACKET;
 			else
 				packet_type = INTER_PACKET;
 			gspca_frame_add(gspca_dev, packet_type,
 					buffer, JEILINJ_MAX_TRANSFER);
 		}
 	}
 quit_stream:
 	mutex_lock(&gspca_dev->usb_lock);
 	if (gspca_dev->present)
 		jlj_stop(gspca_dev);
 	mutex_unlock(&gspca_dev->usb_lock);
 	kfree(buffer);
 }

 /* This function is called at probe time just before sd_init */
 static int sd_config(struct gspca_dev *gspca_dev,
 		const struct usb_device_id *id)
 {
 	struct cam *cam = &gspca_dev->cam;
 	struct sd *dev  = (struct sd *) gspca_dev;

 	dev->quality  = 85;
 	dev->jpegqual = 85;
 	PDEBUG(D_PROBE,
 		"JEILINJ camera detected"
 		" (vid/pid 0x%04X:0x%04X)", id->idVendor, id->idProduct);
 	cam->cam_mode = jlj_mode;
 	cam->nmodes = 1;
 	cam->bulk = 1;
 	/* We don't use the buffer gspca allocates so make it small. */
 	cam->bulk_size = 32;
 	INIT_WORK(&dev->work_struct, jlj_dostream);
 	return 0;
 }

 /* called on streamoff with alt==0 and on disconnect */
 /* the usb_lock is held at entry - restore on exit */
 static void sd_stop0(struct gspca_dev *gspca_dev)
 {
 	struct sd *dev = (struct sd *) gspca_dev;

 	/* wait for the work queue to terminate */
 	mutex_unlock(&gspca_dev->usb_lock);
 	/* This waits for jlj_dostream to finish */
 	destroy_workqueue(dev->work_thread);
 	dev->work_thread = NULL;
 	mutex_lock(&gspca_dev->usb_lock);
 }

 /* this function is called at probe and resume time */
 static int sd_init(struct gspca_dev *gspca_dev)
 {
 	return 0;
 }

 /* Set up for getting frames. */
 static int sd_start(struct gspca_dev *gspca_dev)
 {
 	struct sd *dev = (struct sd *) gspca_dev;
 	int ret;

 	/* create the JPEG header */
 	jpeg_define(dev->jpeg_hdr, gspca_dev->height, gspca_dev->width,
 			0x21);          /* JPEG 422 */
 	jpeg_set_qual(dev->jpeg_hdr, dev->quality);
 	PDEBUG(D_STREAM, "Start streaming at 320x240");
 	ret = jlj_start(gspca_dev);
 	if (ret < 0) {
 		PDEBUG(D_ERR, "Start streaming command failed");
 		return ret;
 	}
 	/* Start the workqueue function to do the streaming */
 	dev->work_thread = create_singlethread_workqueue(MODULE_NAME);
 	queue_work(dev->work_thread, &dev->work_struct);

 	return 0;
 }

 /* Table of supported USB devices */
 static const struct usb_device_id device_table[] = {
 	{USB_DEVICE(0x0979, 0x0280)},
 	{}
 };

 MODULE_DEVICE_TABLE(usb, device_table);

 /* sub-driver description */
 static const struct sd_desc sd_desc = {
 	.name   = MODULE_NAME,
 	.config = sd_config,
 	.init   = sd_init,
 	.start  = sd_start,
 	.stop0  = sd_stop0,
 };

 /* -- device connect -- */
 static int sd_probe(struct usb_interface *intf,
 		const struct usb_device_id *id)
 {
 	return gspca_dev_probe(intf, id,
 			&sd_desc,
 			sizeof(struct sd),
 			THIS_MODULE);
 }

 static struct usb_driver sd_driver = {
 	.name       = MODULE_NAME,
 	.id_table   = device_table,
 	.probe      = sd_probe,
 	.disconnect = gspca_disconnect,
 #ifdef CONFIG_PM
 	.suspend = gspca_suspend,
 	.resume  = gspca_resume,
 #endif
 };

 /* -- module insert / remove -- */
 static int __init sd_mod_init(void)
 {
 	return usb_register(&sd_driver);
 }

 static void __exit sd_mod_exit(void)
 {
 	usb_deregister(&sd_driver);
 }

 module_init(sd_mod_init);
 module_exit(sd_mod_exit);
	/*
	* Jeilinj subdriver
	*
	* Supports some Jeilin dual-mode cameras which use bulk transport and
	* download raw JPEG data.
	*
	* Copyright (C) 2009 Theodore Kilgore
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#define MODULE_NAME "jeilinj"

	#include <linux/workqueue.h>
	#include <linux/slab.h>
	#include "gspca.h"
	#include "jpeg.h"

	MODULE_AUTHOR("Theodore Kilgore <kilgota@auburn.edu>");
	MODULE_DESCRIPTION("GSPCA/JEILINJ USB Camera Driver");
	MODULE_LICENSE("GPL");

	/* Default timeouts, in ms */
	#define JEILINJ_CMD_TIMEOUT 500
	#define JEILINJ_DATA_TIMEOUT 1000

	/* Maximum transfer size to use. */
	#define JEILINJ_MAX_TRANSFER 0x200

	#define FRAME_HEADER_LEN 0x10

	/* Structure to hold all of our device specific stuff */
	struct sd {
	struct gspca_dev gspca_dev; /* !! must be the first item */
	const struct v4l2_pix_format *cap_mode;
	/* Driver stuff */
	struct work_struct work_struct;
	struct workqueue_struct *work_thread;
	u8 quality; /* image quality */
	u8 jpegqual; /* webcam quality */
	u8 jpeg_hdr[JPEG_HDR_SZ];
	};

	struct jlj_command {
	unsigned char instruction[2];
	unsigned char ack_wanted;
	};

	/* AFAICT these cameras will only do 320x240. */
	static struct v4l2_pix_format jlj_mode[] = {
	{ 320, 240, V4L2_PIX_FMT_JPEG, V4L2_FIELD_NONE,
	.bytesperline = 320,
	.sizeimage = 320 * 240,
	.colorspace = V4L2_COLORSPACE_JPEG,
	.priv = 0}
	};

	/*
	* cam uses endpoint 0x03 to send commands, 0x84 for read commands,
	* and 0x82 for bulk transfer.
	*/

	/* All commands are two bytes only */
	static int jlj_write2(struct gspca_dev gspca_dev, unsigned char command)
	{
	int retval;

	memcpy(gspca_dev->usb_buf, command, 2);
	retval = usb_bulk_msg(gspca_dev->dev,
	usb_sndbulkpipe(gspca_dev->dev, 3),
	gspca_dev->usb_buf, 2, NULL, 500);
	if (retval < 0)
	err("command write [%02x] error %d",
	gspca_dev->usb_buf[0], retval);
	return retval;
	}

	/* Responses are one byte only */
	static int jlj_read1(struct gspca_dev *gspca_dev, unsigned char response)
	{
	int retval;

	retval = usb_bulk_msg(gspca_dev->dev,
	usb_rcvbulkpipe(gspca_dev->dev, 0x84),
	gspca_dev->usb_buf, 1, NULL, 500);
	response = gspca_dev->usb_buf[0];
	if (retval < 0)
	err("read command [%02x] error %d",
	gspca_dev->usb_buf[0], retval);
	return retval;
	}

	static int jlj_start(struct gspca_dev *gspca_dev)
	{
	int i;
	int retval = -1;
	u8 response = 0xff;
	struct jlj_command start_commands[] = {
	{{0x71, 0x81}, 0},
	{{0x70, 0x05}, 0},
	{{0x95, 0x70}, 1},
	{{0x71, 0x81}, 0},
	{{0x70, 0x04}, 0},
	{{0x95, 0x70}, 1},
	{{0x71, 0x00}, 0},
	{{0x70, 0x08}, 0},
	{{0x95, 0x70}, 1},
	{{0x94, 0x02}, 0},
	{{0xde, 0x24}, 0},
	{{0x94, 0x02}, 0},
	{{0xdd, 0xf0}, 0},
	{{0x94, 0x02}, 0},
	{{0xe3, 0x2c}, 0},
	{{0x94, 0x02}, 0},
	{{0xe4, 0x00}, 0},
	{{0x94, 0x02}, 0},
	{{0xe5, 0x00}, 0},
	{{0x94, 0x02}, 0},
	{{0xe6, 0x2c}, 0},
	{{0x94, 0x03}, 0},
	{{0xaa, 0x00}, 0},
	{{0x71, 0x1e}, 0},
	{{0x70, 0x06}, 0},
	{{0x71, 0x80}, 0},
	{{0x70, 0x07}, 0}
	};
	for (i = 0; i < ARRAY_SIZE(start_commands); i++) {
	retval = jlj_write2(gspca_dev, start_commands[i].instruction);
	if (retval < 0)
	return retval;
	if (start_commands[i].ack_wanted)
	retval = jlj_read1(gspca_dev, response);
	if (retval < 0)
	return retval;
	}
	PDEBUG(D_ERR, "jlj_start retval is %d", retval);
	return retval;
	}

	static int jlj_stop(struct gspca_dev *gspca_dev)
	{
	int i;
	int retval;
	struct jlj_command stop_commands[] = {
	{{0x71, 0x00}, 0},
	{{0x70, 0x09}, 0},
	{{0x71, 0x80}, 0},
	{{0x70, 0x05}, 0}
	};
	for (i = 0; i < ARRAY_SIZE(stop_commands); i++) {
	retval = jlj_write2(gspca_dev, stop_commands[i].instruction);
	if (retval < 0)
	return retval;
	}
	return retval;
	}

	/* This function is called as a workqueue function and runs whenever the camera
	* is streaming data. Because it is a workqueue function it is allowed to sleep
	* so we can use synchronous USB calls. To avoid possible collisions with other
	* threads attempting to use the camera's USB interface the gspca usb_lock is
	* used when performing the one USB control operation inside the workqueue,
	* which tells the camera to close the stream. In practice the only thing
	* which needs to be protected against is the usb_set_interface call that
	* gspca makes during stream_off. Otherwise the camera doesn't provide any
	* controls that the user could try to change.
	*/

	static void jlj_dostream(struct work_struct *work)
	{
	struct sd *dev = container_of(work, struct sd, work_struct);
	struct gspca_dev *gspca_dev = &dev->gspca_dev;
	int blocks_left; /* 0x200-sized blocks remaining in current frame. */
	int act_len;
	int packet_type;
	int ret;
	u8 *buffer;

	buffer = kmalloc(JEILINJ_MAX_TRANSFER, GFP_KERNEL \| GFP_DMA);
	if (!buffer) {
	err("Couldn't allocate USB buffer");
	goto quit_stream;
	}
	while (gspca_dev->present && gspca_dev->streaming) {
	/*
	* Now request data block 0. Line 0 reports the size
	* to download, in blocks of size 0x200, and also tells the
	* "actual" data size, in bytes, which seems best to ignore.
	*/
	ret = usb_bulk_msg(gspca_dev->dev,
	usb_rcvbulkpipe(gspca_dev->dev, 0x82),
	buffer, JEILINJ_MAX_TRANSFER, &act_len,
	JEILINJ_DATA_TIMEOUT);
	PDEBUG(D_STREAM,
	"Got %d bytes out of %d for Block 0",
	act_len, JEILINJ_MAX_TRANSFER);
	if (ret < 0 \|\| act_len < FRAME_HEADER_LEN)
	goto quit_stream;
	blocks_left = buffer[0x0a] - 1;
	PDEBUG(D_STREAM, "blocks_left = 0x%x", blocks_left);

	/* Start a new frame, and add the JPEG header, first thing */
	gspca_frame_add(gspca_dev, FIRST_PACKET,
	dev->jpeg_hdr, JPEG_HDR_SZ);
	/* Toss line 0 of data block 0, keep the rest. */
	gspca_frame_add(gspca_dev, INTER_PACKET,
	buffer + FRAME_HEADER_LEN,
	JEILINJ_MAX_TRANSFER - FRAME_HEADER_LEN);

	while (blocks_left > 0) {
	if (!gspca_dev->present)
	goto quit_stream;
	ret = usb_bulk_msg(gspca_dev->dev,
	usb_rcvbulkpipe(gspca_dev->dev, 0x82),
	buffer, JEILINJ_MAX_TRANSFER, &act_len,
	JEILINJ_DATA_TIMEOUT);
	if (ret < 0 \|\| act_len < JEILINJ_MAX_TRANSFER)
	goto quit_stream;
	PDEBUG(D_STREAM,
	"%d blocks remaining for frame", blocks_left);
	blocks_left -= 1;
	if (blocks_left == 0)
	packet_type = LAST_PACKET;
	else
	packet_type = INTER_PACKET;
	gspca_frame_add(gspca_dev, packet_type,
	buffer, JEILINJ_MAX_TRANSFER);
	}
	}
	quit_stream:
	mutex_lock(&gspca_dev->usb_lock);
	if (gspca_dev->present)
	jlj_stop(gspca_dev);
	mutex_unlock(&gspca_dev->usb_lock);
	kfree(buffer);
	}

	/* This function is called at probe time just before sd_init */
	static int sd_config(struct gspca_dev *gspca_dev,
	const struct usb_device_id *id)
	{
	struct cam *cam = &gspca_dev->cam;
	struct sd dev = (struct sd ) gspca_dev;

	dev->quality = 85;
	dev->jpegqual = 85;
	PDEBUG(D_PROBE,
	"JEILINJ camera detected"
	" (vid/pid 0x%04X:0x%04X)", id->idVendor, id->idProduct);
	cam->cam_mode = jlj_mode;
	cam->nmodes = 1;
	cam->bulk = 1;
	/* We don't use the buffer gspca allocates so make it small. */
	cam->bulk_size = 32;
	INIT_WORK(&dev->work_struct, jlj_dostream);
	return 0;
	}

	/* called on streamoff with alt==0 and on disconnect */
	/* the usb_lock is held at entry - restore on exit */
	static void sd_stop0(struct gspca_dev *gspca_dev)
	{
	struct sd dev = (struct sd ) gspca_dev;

	/* wait for the work queue to terminate */
	mutex_unlock(&gspca_dev->usb_lock);
	/* This waits for jlj_dostream to finish */
	destroy_workqueue(dev->work_thread);
	dev->work_thread = NULL;
	mutex_lock(&gspca_dev->usb_lock);
	}

	/* this function is called at probe and resume time */
	static int sd_init(struct gspca_dev *gspca_dev)
	{
	return 0;
	}

	/* Set up for getting frames. */
	static int sd_start(struct gspca_dev *gspca_dev)
	{
	struct sd dev = (struct sd ) gspca_dev;
	int ret;

	/* create the JPEG header */
	jpeg_define(dev->jpeg_hdr, gspca_dev->height, gspca_dev->width,
	0x21); /* JPEG 422 */
	jpeg_set_qual(dev->jpeg_hdr, dev->quality);
	PDEBUG(D_STREAM, "Start streaming at 320x240");
	ret = jlj_start(gspca_dev);
	if (ret < 0) {
	PDEBUG(D_ERR, "Start streaming command failed");
	return ret;
	}
	/* Start the workqueue function to do the streaming */
	dev->work_thread = create_singlethread_workqueue(MODULE_NAME);
	queue_work(dev->work_thread, &dev->work_struct);

	return 0;
	}

	/* Table of supported USB devices */
	static const struct usb_device_id device_table[] = {
	{USB_DEVICE(0x0979, 0x0280)},
	{}
	};

	MODULE_DEVICE_TABLE(usb, device_table);

	/* sub-driver description */
	static const struct sd_desc sd_desc = {
	.name = MODULE_NAME,
	.config = sd_config,
	.init = sd_init,
	.start = sd_start,
	.stop0 = sd_stop0,
	};

	/* -- device connect -- */
	static int sd_probe(struct usb_interface *intf,
	const struct usb_device_id *id)
	{
	return gspca_dev_probe(intf, id,
	&sd_desc,
	sizeof(struct sd),
	THIS_MODULE);
	}

	static struct usb_driver sd_driver = {
	.name = MODULE_NAME,
	.id_table = device_table,
	.probe = sd_probe,
	.disconnect = gspca_disconnect,
	#ifdef CONFIG_PM
	.suspend = gspca_suspend,
	.resume = gspca_resume,
	#endif
	};

	/* -- module insert / remove -- */
	static int __init sd_mod_init(void)
	{
	return usb_register(&sd_driver);
	}

	static void __exit sd_mod_exit(void)
	{
	usb_deregister(&sd_driver);
	}

	module_init(sd_mod_init);
	module_exit(sd_mod_exit);