drivers/media/video/gspca/stv06xx/stv06xx.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright (c) 2001 Jean-Fredric Clere, Nikolas Zimmermann, Georg Acher
  *		      Mark Cave-Ayland, Carlo E Prelz, Dick Streefland
  * Copyright (c) 2002, 2003 Tuukka Toivonen
  * Copyright (c) 2008 Erik Andrén
  *
  * 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
  * (at your option) 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
  *
  * P/N 861037:      Sensor HDCS1000        ASIC STV0600
  * P/N 861050-0010: Sensor HDCS1000        ASIC STV0600
  * P/N 861050-0020: Sensor Photobit PB100  ASIC STV0600-1 - QuickCam Express
  * P/N 861055:      Sensor ST VV6410       ASIC STV0610   - LEGO cam
  * P/N 861075-0040: Sensor HDCS1000        ASIC
  * P/N 961179-0700: Sensor ST VV6410       ASIC STV0602   - Dexxa WebCam USB
  * P/N 861040-0000: Sensor ST VV6410       ASIC STV0610   - QuickCam Web
  */

 #include "stv06xx_sensor.h"

 MODULE_AUTHOR("Erik Andrén");
 MODULE_DESCRIPTION("STV06XX USB Camera Driver");
 MODULE_LICENSE("GPL");

 static int dump_bridge;
 static int dump_sensor;

 int stv06xx_write_bridge(struct sd *sd, u16 address, u16 i2c_data)
 {
 	int err;
 	struct usb_device *udev = sd->gspca_dev.dev;
 	__u8 *buf = sd->gspca_dev.usb_buf;
 	u8 len = (i2c_data > 0xff) ? 2 : 1;

 	buf[0] = i2c_data & 0xff;
 	buf[1] = (i2c_data >> 8) & 0xff;

 	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 			      0x04, 0x40, address, 0, buf, len,
 			      STV06XX_URB_MSG_TIMEOUT);

 	PDEBUG(D_CONF, "Written 0x%x to address 0x%x, status: %d",
 	       i2c_data, address, err);

 	return (err < 0) ? err : 0;
 }

 int stv06xx_read_bridge(struct sd *sd, u16 address, u8 *i2c_data)
 {
 	int err;
 	struct usb_device *udev = sd->gspca_dev.dev;
 	__u8 *buf = sd->gspca_dev.usb_buf;

 	err = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
 			      0x04, 0xc0, address, 0, buf, 1,
 			      STV06XX_URB_MSG_TIMEOUT);

 	*i2c_data = buf[0];

 	PDEBUG(D_CONF, "Reading 0x%x from address 0x%x, status %d",
 	       *i2c_data, address, err);

 	return (err < 0) ? err : 0;
 }

 /* Wraps the normal write sensor bytes / words functions for writing a
    single value */
 int stv06xx_write_sensor(struct sd *sd, u8 address, u16 value)
 {
 	if (sd->sensor->i2c_len == 2) {
 		u16 data[2] = { address, value };
 		return stv06xx_write_sensor_words(sd, data, 1);
 	} else {
 		u8 data[2] = { address, value };
 		return stv06xx_write_sensor_bytes(sd, data, 1);
 	}
 }

 static int stv06xx_write_sensor_finish(struct sd *sd)
 {
 	int err = 0;

 	if (sd->bridge == BRIDGE_STV610) {
 		struct usb_device *udev = sd->gspca_dev.dev;
 		__u8 *buf = sd->gspca_dev.usb_buf;

 		buf[0] = 0;
 		err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 				      0x04, 0x40, 0x1704, 0, buf, 1,
 				      STV06XX_URB_MSG_TIMEOUT);
 	}

 	return (err < 0) ? err : 0;
 }

 int stv06xx_write_sensor_bytes(struct sd *sd, const u8 *data, u8 len)
 {
 	int err, i, j;
 	struct usb_device *udev = sd->gspca_dev.dev;
 	__u8 *buf = sd->gspca_dev.usb_buf;

 	PDEBUG(D_CONF, "I2C: Command buffer contains %d entries", len);
 	for (i = 0; i < len;) {
 		/* Build the command buffer */
 		memset(buf, 0, I2C_BUFFER_LENGTH);
 		for (j = 0; j < I2C_MAX_BYTES && i < len; j++, i++) {
 			buf[j] = data[2*i];
 			buf[0x10 + j] = data[2*i+1];
 			PDEBUG(D_CONF, "I2C: Writing 0x%02x to reg 0x%02x",
 			data[2*i+1], data[2*i]);
 		}
 		buf[0x20] = sd->sensor->i2c_addr;
 		buf[0x21] = j - 1; /* Number of commands to send - 1 */
 		buf[0x22] = I2C_WRITE_CMD;
 		err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 				      0x04, 0x40, 0x0400, 0, buf,
 				      I2C_BUFFER_LENGTH,
 				      STV06XX_URB_MSG_TIMEOUT);
 		if (err < 0)
 			return err;
 	}
 	return stv06xx_write_sensor_finish(sd);
 }

 int stv06xx_write_sensor_words(struct sd *sd, const u16 *data, u8 len)
 {
 	int err, i, j;
 	struct usb_device *udev = sd->gspca_dev.dev;
 	__u8 *buf = sd->gspca_dev.usb_buf;

 	PDEBUG(D_CONF, "I2C: Command buffer contains %d entries", len);

 	for (i = 0; i < len;) {
 		/* Build the command buffer */
 		memset(buf, 0, I2C_BUFFER_LENGTH);
 		for (j = 0; j < I2C_MAX_WORDS && i < len; j++, i++) {
 			buf[j] = data[2*i];
 			buf[0x10 + j * 2] = data[2*i+1];
 			buf[0x10 + j * 2 + 1] = data[2*i+1] >> 8;
 			PDEBUG(D_CONF, "I2C: Writing 0x%04x to reg 0x%02x",
 				data[2*i+1], data[2*i]);
 		}
 		buf[0x20] = sd->sensor->i2c_addr;
 		buf[0x21] = j - 1; /* Number of commands to send - 1 */
 		buf[0x22] = I2C_WRITE_CMD;
 		err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 				0x04, 0x40, 0x0400, 0, buf,
 				I2C_BUFFER_LENGTH,
 				STV06XX_URB_MSG_TIMEOUT);
 		if (err < 0)
 			return err;
 	}
 	return stv06xx_write_sensor_finish(sd);
 }

 int stv06xx_read_sensor(struct sd *sd, const u8 address, u16 *value)
 {
 	int err;
 	struct usb_device *udev = sd->gspca_dev.dev;
 	__u8 *buf = sd->gspca_dev.usb_buf;

 	err = stv06xx_write_bridge(sd, STV_I2C_FLUSH, sd->sensor->i2c_flush);
 	if (err < 0)
 		return err;

 	/* Clear mem */
 	memset(buf, 0, I2C_BUFFER_LENGTH);

 	buf[0] = address;
 	buf[0x20] = sd->sensor->i2c_addr;
 	buf[0x21] = 0;

 	/* Read I2C register */
 	buf[0x22] = I2C_READ_CMD;

 	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 			      0x04, 0x40, 0x1400, 0, buf, I2C_BUFFER_LENGTH,
 			      STV06XX_URB_MSG_TIMEOUT);
 	if (err < 0) {
 		PDEBUG(D_ERR, "I2C: Read error writing address: %d", err);
 		return err;
 	}

 	err = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
 			      0x04, 0xc0, 0x1410, 0, buf, sd->sensor->i2c_len,
 			      STV06XX_URB_MSG_TIMEOUT);
 	if (sd->sensor->i2c_len == 2)
 		*value = buf[0] | (buf[1] << 8);
 	else
 		*value = buf[0];

 	PDEBUG(D_CONF, "I2C: Read 0x%x from address 0x%x, status: %d",
 	       *value, address, err);

 	return (err < 0) ? err : 0;
 }

 /* Dumps all bridge registers */
 static void stv06xx_dump_bridge(struct sd *sd)
 {
 	int i;
 	u8 data, buf;

 	info("Dumping all stv06xx bridge registers");
 	for (i = 0x1400; i < 0x160f; i++) {
 		stv06xx_read_bridge(sd, i, &data);

 		info("Read 0x%x from address 0x%x", data, i);
 	}

 	for (i = 0x1400; i < 0x160f; i++) {
 		stv06xx_read_bridge(sd, i, &data);
 		buf = data;

 		stv06xx_write_bridge(sd, i, 0xff);
 		stv06xx_read_bridge(sd, i, &data);
 		if (data == 0xff)
 			info("Register 0x%x is read/write", i);
 		else if (data != buf)
 			info("Register 0x%x is read/write,"
 			     "but only partially", i);
 		else
 			info("Register 0x%x is read-only", i);

 		stv06xx_write_bridge(sd, i, buf);
 	}
 }

 /* this function is called at probe and resume time */
 static int stv06xx_init(struct gspca_dev *gspca_dev)
 {
 	struct sd *sd = (struct sd *) gspca_dev;
 	int err;

 	PDEBUG(D_PROBE, "Initializing camera");

 	/* Let the usb init settle for a bit
 	   before performing the initialization */
 	msleep(250);

 	err = sd->sensor->init(sd);

 	if (dump_sensor && sd->sensor->dump)
 		sd->sensor->dump(sd);

 	return (err < 0) ? err : 0;
 }

 /* Start the camera */
 static int stv06xx_start(struct gspca_dev *gspca_dev)
 {
 	struct sd *sd = (struct sd *) gspca_dev;
 	int err;

 	/* Prepare the sensor for start */
 	err = sd->sensor->start(sd);
 	if (err < 0)
 		goto out;

 	/* Start isochronous streaming */
 	err = stv06xx_write_bridge(sd, STV_ISO_ENABLE, 1);

 out:
 	if (err < 0)
 		PDEBUG(D_STREAM, "Starting stream failed");
 	else
 		PDEBUG(D_STREAM, "Started streaming");

 	return (err < 0) ? err : 0;
 }

 static void stv06xx_stopN(struct gspca_dev *gspca_dev)
 {
 	int err;
 	struct sd *sd = (struct sd *) gspca_dev;

 	/* stop ISO-streaming */
 	err = stv06xx_write_bridge(sd, STV_ISO_ENABLE, 0);
 	if (err < 0)
 		goto out;

 	err = sd->sensor->stop(sd);

 out:
 	if (err < 0)
 		PDEBUG(D_STREAM, "Failed to stop stream");
 	else
 		PDEBUG(D_STREAM, "Stopped streaming");
 }

 /*
  * Analyse an USB packet of the data stream and store it appropriately.
  * Each packet contains an integral number of chunks. Each chunk has
  * 2-bytes identification, followed by 2-bytes that describe the chunk
  * length. Known/guessed chunk identifications are:
  * 8001/8005/C001/C005 - Begin new frame
  * 8002/8006/C002/C006 - End frame
  * 0200/4200           - Contains actual image data, bayer or compressed
  * 0005                - 11 bytes of unknown data
  * 0100                - 2 bytes of unknown data
  * The 0005 and 0100 chunks seem to appear only in compressed stream.
  */
 static void stv06xx_pkt_scan(struct gspca_dev *gspca_dev,
 			struct gspca_frame *frame,	/* target */
 			__u8 *data,			/* isoc packet */
 			int len)			/* iso packet length */
 {
 	struct sd *sd = (struct sd *) gspca_dev;

 	PDEBUG(D_PACK, "Packet of length %d arrived", len);

 	/* A packet may contain several frames
 	   loop until the whole packet is reached */
 	while (len) {
 		int id, chunk_len;

 		if (len < 4) {
 			PDEBUG(D_PACK, "Packet is smaller than 4 bytes");
 			return;
 		}

 		/* Capture the id */
 		id = (data[0] << 8) | data[1];

 		/* Capture the chunk length */
 		chunk_len = (data[2] << 8) | data[3];
 		PDEBUG(D_PACK, "Chunk id: %x, length: %d", id, chunk_len);

 		data += 4;
 		len -= 4;

 		if (len < chunk_len) {
 			PDEBUG(D_ERR, "URB packet length is smaller"
 				" than the specified chunk length");
 			gspca_dev->last_packet_type = DISCARD_PACKET;
 			return;
 		}

 		/* First byte seem to be 02=data 2nd byte is unknown??? */
 		if (sd->bridge == BRIDGE_ST6422 && (id & 0xFF00) == 0x0200)
 			goto frame_data;

 		switch (id) {
 		case 0x0200:
 		case 0x4200:
 frame_data:
 			PDEBUG(D_PACK, "Frame data packet detected");

 			if (sd->to_skip) {
 				int skip = (sd->to_skip < chunk_len) ?
 					    sd->to_skip : chunk_len;
 				data += skip;
 				len -= skip;
 				chunk_len -= skip;
 				sd->to_skip -= skip;
 			}

 			gspca_frame_add(gspca_dev, INTER_PACKET, frame,
 					data, chunk_len);
 			break;

 		case 0x8001:
 		case 0x8005:
 		case 0xc001:
 		case 0xc005:
 			PDEBUG(D_PACK, "Starting new frame");

 			/* Create a new frame, chunk length should be zero */
 			gspca_frame_add(gspca_dev, FIRST_PACKET,
 					frame, data, 0);

 			if (sd->bridge == BRIDGE_ST6422)
 				sd->to_skip = gspca_dev->width * 4;

 			if (chunk_len)
 				PDEBUG(D_ERR, "Chunk length is "
 					      "non-zero on a SOF");
 			break;

 		case 0x8002:
 		case 0x8006:
 		case 0xc002:
 			PDEBUG(D_PACK, "End of frame detected");

 			/* Complete the last frame (if any) */
 			gspca_frame_add(gspca_dev, LAST_PACKET, frame, data, 0);

 			if (chunk_len)
 				PDEBUG(D_ERR, "Chunk length is "
 					      "non-zero on a EOF");
 			break;

 		case 0x0005:
 			PDEBUG(D_PACK, "Chunk 0x005 detected");
 			/* Unknown chunk with 11 bytes of data,
 			   occurs just before end of each frame
 			   in compressed mode */
 			break;

 		case 0x0100:
 			PDEBUG(D_PACK, "Chunk 0x0100 detected");
 			/* Unknown chunk with 2 bytes of data,
 			   occurs 2-3 times per USB interrupt */
 			break;
 		case 0x42ff:
 			PDEBUG(D_PACK, "Chunk 0x42ff detected");
 			/* Special chunk seen sometimes on the ST6422 */
 			break;
 		default:
 			PDEBUG(D_PACK, "Unknown chunk 0x%04x detected", id);
 			/* Unknown chunk */
 		}
 		data    += chunk_len;
 		len     -= chunk_len;
 	}
 }

 static int stv06xx_config(struct gspca_dev *gspca_dev,
 			  const struct usb_device_id *id);

 /* sub-driver description */
 static const struct sd_desc sd_desc = {
 	.name = MODULE_NAME,
 	.config = stv06xx_config,
 	.init = stv06xx_init,
 	.start = stv06xx_start,
 	.stopN = stv06xx_stopN,
 	.pkt_scan = stv06xx_pkt_scan
 };

 /* This function is called at probe time */
 static int stv06xx_config(struct gspca_dev *gspca_dev,
 			  const struct usb_device_id *id)
 {
 	struct sd *sd = (struct sd *) gspca_dev;
 	struct cam *cam;

 	PDEBUG(D_PROBE, "Configuring camera");

 	cam = &gspca_dev->cam;
 	sd->desc = sd_desc;
 	sd->bridge = id->driver_info;
 	gspca_dev->sd_desc = &sd->desc;

 	if (dump_bridge)
 		stv06xx_dump_bridge(sd);

 	sd->sensor = &stv06xx_sensor_st6422;
 	if (!sd->sensor->probe(sd))
 		return 0;

 	sd->sensor = &stv06xx_sensor_vv6410;
 	if (!sd->sensor->probe(sd))
 		return 0;

 	sd->sensor = &stv06xx_sensor_hdcs1x00;
 	if (!sd->sensor->probe(sd))
 		return 0;

 	sd->sensor = &stv06xx_sensor_hdcs1020;
 	if (!sd->sensor->probe(sd))
 		return 0;

 	sd->sensor = &stv06xx_sensor_pb0100;
 	if (!sd->sensor->probe(sd))
 		return 0;

 	sd->sensor = NULL;
 	return -ENODEV;
 }


 /* -- module initialisation -- */
 static const __devinitdata struct usb_device_id device_table[] = {
 	/* QuickCam Express */
 	{USB_DEVICE(0x046d, 0x0840), .driver_info = BRIDGE_STV600 },
 	/* LEGO cam / QuickCam Web */
 	{USB_DEVICE(0x046d, 0x0850), .driver_info = BRIDGE_STV610 },
 	/* Dexxa WebCam USB */
 	{USB_DEVICE(0x046d, 0x0870), .driver_info = BRIDGE_STV602 },
 	/* QuickCam Messenger */
 	{USB_DEVICE(0x046D, 0x08F0), .driver_info = BRIDGE_ST6422 },
 	/* QuickCam Communicate */
 	{USB_DEVICE(0x046D, 0x08F5), .driver_info = BRIDGE_ST6422 },
 	/* QuickCam Messenger (new) */
 	{USB_DEVICE(0x046D, 0x08F6), .driver_info = BRIDGE_ST6422 },
 	/* QuickCam Messenger (new) */
 	{USB_DEVICE(0x046D, 0x08DA), .driver_info = BRIDGE_ST6422 },
 	{}
 };
 MODULE_DEVICE_TABLE(usb, device_table);

 /* -- device connect -- */
 static int sd_probe(struct usb_interface *intf,
 			const struct usb_device_id *id)
 {
 	PDEBUG(D_PROBE, "Probing for a stv06xx device");
 	return gspca_dev_probe(intf, id, &sd_desc, sizeof(struct sd),
 			       THIS_MODULE);
 }

 static void sd_disconnect(struct usb_interface *intf)
 {
 	struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
 	struct sd *sd = (struct sd *) gspca_dev;
 	PDEBUG(D_PROBE, "Disconnecting the stv06xx device");

 	if (sd->sensor->disconnect)
 		sd->sensor->disconnect(sd);
 	gspca_disconnect(intf);
 }

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

 /* -- module insert / remove -- */
 static int __init sd_mod_init(void)
 {
 	int ret;
 	ret = usb_register(&sd_driver);
 	if (ret < 0)
 		return ret;
 	PDEBUG(D_PROBE, "registered");
 	return 0;
 }
 static void __exit sd_mod_exit(void)
 {
 	usb_deregister(&sd_driver);
 	PDEBUG(D_PROBE, "deregistered");
 }

 module_init(sd_mod_init);
 module_exit(sd_mod_exit);

 module_param(dump_bridge, bool, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(dump_bridge, "Dumps all usb bridge registers at startup");

 module_param(dump_sensor, bool, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(dump_sensor, "Dumps all sensor registers at startup");
	/*
	* Copyright (c) 2001 Jean-Fredric Clere, Nikolas Zimmermann, Georg Acher
	* Mark Cave-Ayland, Carlo E Prelz, Dick Streefland
	* Copyright (c) 2002, 2003 Tuukka Toivonen
	* Copyright (c) 2008 Erik Andrén
	*
	* 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
	* (at your option) 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
	*
	* P/N 861037: Sensor HDCS1000 ASIC STV0600
	* P/N 861050-0010: Sensor HDCS1000 ASIC STV0600
	* P/N 861050-0020: Sensor Photobit PB100 ASIC STV0600-1 - QuickCam Express
	* P/N 861055: Sensor ST VV6410 ASIC STV0610 - LEGO cam
	* P/N 861075-0040: Sensor HDCS1000 ASIC
	* P/N 961179-0700: Sensor ST VV6410 ASIC STV0602 - Dexxa WebCam USB
	* P/N 861040-0000: Sensor ST VV6410 ASIC STV0610 - QuickCam Web
	*/

	#include "stv06xx_sensor.h"

	MODULE_AUTHOR("Erik Andrén");
	MODULE_DESCRIPTION("STV06XX USB Camera Driver");
	MODULE_LICENSE("GPL");

	static int dump_bridge;
	static int dump_sensor;

	int stv06xx_write_bridge(struct sd *sd, u16 address, u16 i2c_data)
	{
	int err;
	struct usb_device *udev = sd->gspca_dev.dev;
	__u8 *buf = sd->gspca_dev.usb_buf;
	u8 len = (i2c_data > 0xff) ? 2 : 1;

	buf[0] = i2c_data & 0xff;
	buf[1] = (i2c_data >> 8) & 0xff;

	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
	0x04, 0x40, address, 0, buf, len,
	STV06XX_URB_MSG_TIMEOUT);

	PDEBUG(D_CONF, "Written 0x%x to address 0x%x, status: %d",
	i2c_data, address, err);

	return (err < 0) ? err : 0;
	}

	int stv06xx_read_bridge(struct sd sd, u16 address, u8 i2c_data)
	{
	int err;
	struct usb_device *udev = sd->gspca_dev.dev;
	__u8 *buf = sd->gspca_dev.usb_buf;

	err = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
	0x04, 0xc0, address, 0, buf, 1,
	STV06XX_URB_MSG_TIMEOUT);

	*i2c_data = buf[0];

	PDEBUG(D_CONF, "Reading 0x%x from address 0x%x, status %d",
	*i2c_data, address, err);

	return (err < 0) ? err : 0;
	}

	/* Wraps the normal write sensor bytes / words functions for writing a
	single value */
	int stv06xx_write_sensor(struct sd *sd, u8 address, u16 value)
	{
	if (sd->sensor->i2c_len == 2) {
	u16 data[2] = { address, value };
	return stv06xx_write_sensor_words(sd, data, 1);
	} else {
	u8 data[2] = { address, value };
	return stv06xx_write_sensor_bytes(sd, data, 1);
	}
	}

	static int stv06xx_write_sensor_finish(struct sd *sd)
	{
	int err = 0;

	if (sd->bridge == BRIDGE_STV610) {
	struct usb_device *udev = sd->gspca_dev.dev;
	__u8 *buf = sd->gspca_dev.usb_buf;

	buf[0] = 0;
	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
	0x04, 0x40, 0x1704, 0, buf, 1,
	STV06XX_URB_MSG_TIMEOUT);
	}

	return (err < 0) ? err : 0;
	}

	int stv06xx_write_sensor_bytes(struct sd sd, const u8 data, u8 len)
	{
	int err, i, j;
	struct usb_device *udev = sd->gspca_dev.dev;
	__u8 *buf = sd->gspca_dev.usb_buf;

	PDEBUG(D_CONF, "I2C: Command buffer contains %d entries", len);
	for (i = 0; i < len;) {
	/* Build the command buffer */
	memset(buf, 0, I2C_BUFFER_LENGTH);
	for (j = 0; j < I2C_MAX_BYTES && i < len; j++, i++) {
	buf[j] = data[2*i];
	buf[0x10 + j] = data[2*i+1];
	PDEBUG(D_CONF, "I2C: Writing 0x%02x to reg 0x%02x",
	data[2i+1], data[2i]);
	}
	buf[0x20] = sd->sensor->i2c_addr;
	buf[0x21] = j - 1; /* Number of commands to send - 1 */
	buf[0x22] = I2C_WRITE_CMD;
	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
	0x04, 0x40, 0x0400, 0, buf,
	I2C_BUFFER_LENGTH,
	STV06XX_URB_MSG_TIMEOUT);
	if (err < 0)
	return err;
	}
	return stv06xx_write_sensor_finish(sd);
	}

	int stv06xx_write_sensor_words(struct sd sd, const u16 data, u8 len)
	{
	int err, i, j;
	struct usb_device *udev = sd->gspca_dev.dev;
	__u8 *buf = sd->gspca_dev.usb_buf;

	PDEBUG(D_CONF, "I2C: Command buffer contains %d entries", len);

	for (i = 0; i < len;) {
	/* Build the command buffer */
	memset(buf, 0, I2C_BUFFER_LENGTH);
	for (j = 0; j < I2C_MAX_WORDS && i < len; j++, i++) {
	buf[j] = data[2*i];
	buf[0x10 + j * 2] = data[2*i+1];
	buf[0x10 + j * 2 + 1] = data[2*i+1] >> 8;
	PDEBUG(D_CONF, "I2C: Writing 0x%04x to reg 0x%02x",
	data[2i+1], data[2i]);
	}
	buf[0x20] = sd->sensor->i2c_addr;
	buf[0x21] = j - 1; /* Number of commands to send - 1 */
	buf[0x22] = I2C_WRITE_CMD;
	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
	0x04, 0x40, 0x0400, 0, buf,
	I2C_BUFFER_LENGTH,
	STV06XX_URB_MSG_TIMEOUT);
	if (err < 0)
	return err;
	}
	return stv06xx_write_sensor_finish(sd);
	}

	int stv06xx_read_sensor(struct sd sd, const u8 address, u16 value)
	{
	int err;
	struct usb_device *udev = sd->gspca_dev.dev;
	__u8 *buf = sd->gspca_dev.usb_buf;

	err = stv06xx_write_bridge(sd, STV_I2C_FLUSH, sd->sensor->i2c_flush);
	if (err < 0)
	return err;

	/* Clear mem */
	memset(buf, 0, I2C_BUFFER_LENGTH);

	buf[0] = address;
	buf[0x20] = sd->sensor->i2c_addr;
	buf[0x21] = 0;

	/* Read I2C register */
	buf[0x22] = I2C_READ_CMD;

	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
	0x04, 0x40, 0x1400, 0, buf, I2C_BUFFER_LENGTH,
	STV06XX_URB_MSG_TIMEOUT);
	if (err < 0) {
	PDEBUG(D_ERR, "I2C: Read error writing address: %d", err);
	return err;
	}

	err = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
	0x04, 0xc0, 0x1410, 0, buf, sd->sensor->i2c_len,
	STV06XX_URB_MSG_TIMEOUT);
	if (sd->sensor->i2c_len == 2)
	*value = buf[0] \| (buf[1] << 8);
	else
	*value = buf[0];

	PDEBUG(D_CONF, "I2C: Read 0x%x from address 0x%x, status: %d",
	*value, address, err);

	return (err < 0) ? err : 0;
	}

	/* Dumps all bridge registers */
	static void stv06xx_dump_bridge(struct sd *sd)
	{
	int i;
	u8 data, buf;

	info("Dumping all stv06xx bridge registers");
	for (i = 0x1400; i < 0x160f; i++) {
	stv06xx_read_bridge(sd, i, &data);

	info("Read 0x%x from address 0x%x", data, i);
	}

	for (i = 0x1400; i < 0x160f; i++) {
	stv06xx_read_bridge(sd, i, &data);
	buf = data;

	stv06xx_write_bridge(sd, i, 0xff);
	stv06xx_read_bridge(sd, i, &data);
	if (data == 0xff)
	info("Register 0x%x is read/write", i);
	else if (data != buf)
	info("Register 0x%x is read/write,"
	"but only partially", i);
	else
	info("Register 0x%x is read-only", i);

	stv06xx_write_bridge(sd, i, buf);
	}
	}

	/* this function is called at probe and resume time */
	static int stv06xx_init(struct gspca_dev *gspca_dev)
	{
	struct sd sd = (struct sd ) gspca_dev;
	int err;

	PDEBUG(D_PROBE, "Initializing camera");

	/* Let the usb init settle for a bit
	before performing the initialization */
	msleep(250);

	err = sd->sensor->init(sd);

	if (dump_sensor && sd->sensor->dump)
	sd->sensor->dump(sd);

	return (err < 0) ? err : 0;
	}

	/* Start the camera */
	static int stv06xx_start(struct gspca_dev *gspca_dev)
	{
	struct sd sd = (struct sd ) gspca_dev;
	int err;

	/* Prepare the sensor for start */
	err = sd->sensor->start(sd);
	if (err < 0)
	goto out;

	/* Start isochronous streaming */
	err = stv06xx_write_bridge(sd, STV_ISO_ENABLE, 1);

	out:
	if (err < 0)
	PDEBUG(D_STREAM, "Starting stream failed");
	else
	PDEBUG(D_STREAM, "Started streaming");

	return (err < 0) ? err : 0;
	}

	static void stv06xx_stopN(struct gspca_dev *gspca_dev)
	{
	int err;
	struct sd sd = (struct sd ) gspca_dev;

	/* stop ISO-streaming */
	err = stv06xx_write_bridge(sd, STV_ISO_ENABLE, 0);
	if (err < 0)
	goto out;

	err = sd->sensor->stop(sd);

	out:
	if (err < 0)
	PDEBUG(D_STREAM, "Failed to stop stream");
	else
	PDEBUG(D_STREAM, "Stopped streaming");
	}

	/*
	* Analyse an USB packet of the data stream and store it appropriately.
	* Each packet contains an integral number of chunks. Each chunk has
	* 2-bytes identification, followed by 2-bytes that describe the chunk
	* length. Known/guessed chunk identifications are:
	* 8001/8005/C001/C005 - Begin new frame
	* 8002/8006/C002/C006 - End frame
	* 0200/4200 - Contains actual image data, bayer or compressed
	* 0005 - 11 bytes of unknown data
	* 0100 - 2 bytes of unknown data
	* The 0005 and 0100 chunks seem to appear only in compressed stream.
	*/
	static void stv06xx_pkt_scan(struct gspca_dev *gspca_dev,
	struct gspca_frame frame, / target */
	__u8 data, / isoc packet */
	int len) /* iso packet length */
	{
	struct sd sd = (struct sd ) gspca_dev;

	PDEBUG(D_PACK, "Packet of length %d arrived", len);

	/* A packet may contain several frames
	loop until the whole packet is reached */
	while (len) {
	int id, chunk_len;

	if (len < 4) {
	PDEBUG(D_PACK, "Packet is smaller than 4 bytes");
	return;
	}

	/* Capture the id */
	id = (data[0] << 8) \| data[1];

	/* Capture the chunk length */
	chunk_len = (data[2] << 8) \| data[3];
	PDEBUG(D_PACK, "Chunk id: %x, length: %d", id, chunk_len);

	data += 4;
	len -= 4;

	if (len < chunk_len) {
	PDEBUG(D_ERR, "URB packet length is smaller"
	" than the specified chunk length");
	gspca_dev->last_packet_type = DISCARD_PACKET;
	return;
	}

	/* First byte seem to be 02=data 2nd byte is unknown??? */
	if (sd->bridge == BRIDGE_ST6422 && (id & 0xFF00) == 0x0200)
	goto frame_data;

	switch (id) {
	case 0x0200:
	case 0x4200:
	frame_data:
	PDEBUG(D_PACK, "Frame data packet detected");

	if (sd->to_skip) {
	int skip = (sd->to_skip < chunk_len) ?
	sd->to_skip : chunk_len;
	data += skip;
	len -= skip;
	chunk_len -= skip;
	sd->to_skip -= skip;
	}

	gspca_frame_add(gspca_dev, INTER_PACKET, frame,
	data, chunk_len);
	break;

	case 0x8001:
	case 0x8005:
	case 0xc001:
	case 0xc005:
	PDEBUG(D_PACK, "Starting new frame");

	/* Create a new frame, chunk length should be zero */
	gspca_frame_add(gspca_dev, FIRST_PACKET,
	frame, data, 0);

	if (sd->bridge == BRIDGE_ST6422)
	sd->to_skip = gspca_dev->width * 4;

	if (chunk_len)
	PDEBUG(D_ERR, "Chunk length is "
	"non-zero on a SOF");
	break;

	case 0x8002:
	case 0x8006:
	case 0xc002:
	PDEBUG(D_PACK, "End of frame detected");

	/* Complete the last frame (if any) */
	gspca_frame_add(gspca_dev, LAST_PACKET, frame, data, 0);

	if (chunk_len)
	PDEBUG(D_ERR, "Chunk length is "
	"non-zero on a EOF");
	break;

	case 0x0005:
	PDEBUG(D_PACK, "Chunk 0x005 detected");
	/* Unknown chunk with 11 bytes of data,
	occurs just before end of each frame
	in compressed mode */
	break;

	case 0x0100:
	PDEBUG(D_PACK, "Chunk 0x0100 detected");
	/* Unknown chunk with 2 bytes of data,
	occurs 2-3 times per USB interrupt */
	break;
	case 0x42ff:
	PDEBUG(D_PACK, "Chunk 0x42ff detected");
	/* Special chunk seen sometimes on the ST6422 */
	break;
	default:
	PDEBUG(D_PACK, "Unknown chunk 0x%04x detected", id);
	/* Unknown chunk */
	}
	data += chunk_len;
	len -= chunk_len;
	}
	}

	static int stv06xx_config(struct gspca_dev *gspca_dev,
	const struct usb_device_id *id);

	/* sub-driver description */
	static const struct sd_desc sd_desc = {
	.name = MODULE_NAME,
	.config = stv06xx_config,
	.init = stv06xx_init,
	.start = stv06xx_start,
	.stopN = stv06xx_stopN,
	.pkt_scan = stv06xx_pkt_scan
	};

	/* This function is called at probe time */
	static int stv06xx_config(struct gspca_dev *gspca_dev,
	const struct usb_device_id *id)
	{
	struct sd sd = (struct sd ) gspca_dev;
	struct cam *cam;

	PDEBUG(D_PROBE, "Configuring camera");

	cam = &gspca_dev->cam;
	sd->desc = sd_desc;
	sd->bridge = id->driver_info;
	gspca_dev->sd_desc = &sd->desc;

	if (dump_bridge)
	stv06xx_dump_bridge(sd);

	sd->sensor = &stv06xx_sensor_st6422;
	if (!sd->sensor->probe(sd))
	return 0;

	sd->sensor = &stv06xx_sensor_vv6410;
	if (!sd->sensor->probe(sd))
	return 0;

	sd->sensor = &stv06xx_sensor_hdcs1x00;
	if (!sd->sensor->probe(sd))
	return 0;

	sd->sensor = &stv06xx_sensor_hdcs1020;
	if (!sd->sensor->probe(sd))
	return 0;

	sd->sensor = &stv06xx_sensor_pb0100;
	if (!sd->sensor->probe(sd))
	return 0;

	sd->sensor = NULL;
	return -ENODEV;
	}



	/* -- module initialisation -- */
	static const __devinitdata struct usb_device_id device_table[] = {
	/* QuickCam Express */
	{USB_DEVICE(0x046d, 0x0840), .driver_info = BRIDGE_STV600 },
	/* LEGO cam / QuickCam Web */
	{USB_DEVICE(0x046d, 0x0850), .driver_info = BRIDGE_STV610 },
	/* Dexxa WebCam USB */
	{USB_DEVICE(0x046d, 0x0870), .driver_info = BRIDGE_STV602 },
	/* QuickCam Messenger */
	{USB_DEVICE(0x046D, 0x08F0), .driver_info = BRIDGE_ST6422 },
	/* QuickCam Communicate */
	{USB_DEVICE(0x046D, 0x08F5), .driver_info = BRIDGE_ST6422 },
	/* QuickCam Messenger (new) */
	{USB_DEVICE(0x046D, 0x08F6), .driver_info = BRIDGE_ST6422 },
	/* QuickCam Messenger (new) */
	{USB_DEVICE(0x046D, 0x08DA), .driver_info = BRIDGE_ST6422 },
	{}
	};
	MODULE_DEVICE_TABLE(usb, device_table);

	/* -- device connect -- */
	static int sd_probe(struct usb_interface *intf,
	const struct usb_device_id *id)
	{
	PDEBUG(D_PROBE, "Probing for a stv06xx device");
	return gspca_dev_probe(intf, id, &sd_desc, sizeof(struct sd),
	THIS_MODULE);
	}

	static void sd_disconnect(struct usb_interface *intf)
	{
	struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
	struct sd sd = (struct sd ) gspca_dev;
	PDEBUG(D_PROBE, "Disconnecting the stv06xx device");

	if (sd->sensor->disconnect)
	sd->sensor->disconnect(sd);
	gspca_disconnect(intf);
	}

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

	/* -- module insert / remove -- */
	static int __init sd_mod_init(void)
	{
	int ret;
	ret = usb_register(&sd_driver);
	if (ret < 0)
	return ret;
	PDEBUG(D_PROBE, "registered");
	return 0;
	}
	static void __exit sd_mod_exit(void)
	{
	usb_deregister(&sd_driver);
	PDEBUG(D_PROBE, "deregistered");
	}

	module_init(sd_mod_init);
	module_exit(sd_mod_exit);

	module_param(dump_bridge, bool, S_IRUGO \| S_IWUSR);
	MODULE_PARM_DESC(dump_bridge, "Dumps all usb bridge registers at startup");

	module_param(dump_sensor, bool, S_IRUGO \| S_IWUSR);
	MODULE_PARM_DESC(dump_sensor, "Dumps all sensor registers at startup");