drivers/media/usb/gspca/m5602/m5602_core.c - linux - Git at Google

  /*
  * USB Driver for ALi m5602 based webcams
  *
  * Copyright (C) 2008 Erik Andrén
  * Copyright (C) 2007 Ilyes Gouta. Based on the m5603x Linux Driver Project.
  * Copyright (C) 2005 m5603x Linux Driver Project <m5602@x3ng.com.br>
  *
  * Portions of code to USB interface and ALi driver software,
  * Copyright (c) 2006 Willem Duinker
  * v4l2 interface modeled after the V4L2 driver
  * for SN9C10x PC Camera Controllers
  *
  * 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, version 2.
  *
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include "m5602_ov9650.h"
 #include "m5602_ov7660.h"
 #include "m5602_mt9m111.h"
 #include "m5602_po1030.h"
 #include "m5602_s5k83a.h"
 #include "m5602_s5k4aa.h"

 /* Kernel module parameters */
 int force_sensor;
 static bool dump_bridge;
 bool dump_sensor;

 static const struct usb_device_id m5602_table[] = {
 	{USB_DEVICE(0x0402, 0x5602)},
 	{}
 };

 MODULE_DEVICE_TABLE(usb, m5602_table);

 /* A skeleton used for sending messages to the sensor */
 static const unsigned char sensor_urb_skeleton[] = {
 	0x23, M5602_XB_GPIO_EN_H, 0x81, 0x06,
 	0x23, M5602_XB_MISC_CTRL, 0x81, 0x80,
 	0x13, M5602_XB_I2C_DEV_ADDR, 0x81, 0x00,
 	0x13, M5602_XB_I2C_REG_ADDR, 0x81, 0x00,
 	0x13, M5602_XB_I2C_DATA, 0x81, 0x00,
 	0x13, M5602_XB_I2C_CTRL, 0x81, 0x11
 };

 /* A skeleton used for sending messages to the m5602 bridge */
 static const unsigned char bridge_urb_skeleton[] = {
 	0x13, 0x00, 0x81, 0x00
 };

 /* Reads a byte from the m5602 */
 int m5602_read_bridge(struct sd *sd, const u8 address, u8 *i2c_data)
 {
 	int err;
 	struct gspca_dev *gspca_dev = (struct gspca_dev *) sd;
 	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, 0x14,
 			      0x8100 + address, buf,
 			      1, M5602_URB_MSG_TIMEOUT);
 	*i2c_data = buf[0];

 	PDEBUG(D_CONF, "Reading bridge register 0x%x containing 0x%x",
 	       address, *i2c_data);

 	/* usb_control_msg(...) returns the number of bytes sent upon success,
 	mask that and return zero instead*/
 	return (err < 0) ? err : 0;
 }

 /* Writes a byte to the m5602 */
 int m5602_write_bridge(struct sd *sd, const u8 address, const u8 i2c_data)
 {
 	int err;
 	struct gspca_dev *gspca_dev = (struct gspca_dev *) sd;
 	struct usb_device *udev = sd->gspca_dev.dev;
 	__u8 *buf = sd->gspca_dev.usb_buf;

 	PDEBUG(D_CONF, "Writing bridge register 0x%x with 0x%x",
 	       address, i2c_data);

 	memcpy(buf, bridge_urb_skeleton,
 	       sizeof(bridge_urb_skeleton));
 	buf[1] = address;
 	buf[3] = i2c_data;

 	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 				0x04, 0x40, 0x19,
 				0x0000, buf,
 				4, M5602_URB_MSG_TIMEOUT);

 	/* usb_control_msg(...) returns the number of bytes sent upon success,
 	   mask that and return zero instead */
 	return (err < 0) ? err : 0;
 }

 static int m5602_wait_for_i2c(struct sd *sd)
 {
 	int err;
 	u8 data;

 	do {
 		err = m5602_read_bridge(sd, M5602_XB_I2C_STATUS, &data);
 	} while ((data & I2C_BUSY) && !err);
 	return err;
 }

 int m5602_read_sensor(struct sd *sd, const u8 address,
 		       u8 *i2c_data, const u8 len)
 {
 	int err, i;
 	struct gspca_dev *gspca_dev = (struct gspca_dev *) sd;

 	if (!len || len > sd->sensor->i2c_regW)
 		return -EINVAL;

 	err = m5602_wait_for_i2c(sd);
 	if (err < 0)
 		return err;

 	err = m5602_write_bridge(sd, M5602_XB_I2C_DEV_ADDR,
 				 sd->sensor->i2c_slave_id);
 	if (err < 0)
 		return err;

 	err = m5602_write_bridge(sd, M5602_XB_I2C_REG_ADDR, address);
 	if (err < 0)
 		return err;

 	/* Sensors with registers that are of only
 	   one byte width are differently read */

 	/* FIXME: This works with the ov9650, but has issues with the po1030 */
 	if (sd->sensor->i2c_regW == 1) {
 		err = m5602_write_bridge(sd, M5602_XB_I2C_CTRL, 1);
 		if (err < 0)
 			return err;

 		err = m5602_write_bridge(sd, M5602_XB_I2C_CTRL, 0x08);
 	} else {
 		err = m5602_write_bridge(sd, M5602_XB_I2C_CTRL, 0x18 + len);
 	}

 	for (i = 0; (i < len) && !err; i++) {
 		err = m5602_wait_for_i2c(sd);
 		if (err < 0)
 			return err;

 		err = m5602_read_bridge(sd, M5602_XB_I2C_DATA, &(i2c_data[i]));

 		PDEBUG(D_CONF, "Reading sensor register "
 			       "0x%x containing 0x%x ", address, *i2c_data);
 	}
 	return err;
 }

 int m5602_write_sensor(struct sd *sd, const u8 address,
 			u8 *i2c_data, const u8 len)
 {
 	int err, i;
 	u8 *p;
 	struct gspca_dev *gspca_dev = (struct gspca_dev *) sd;
 	struct usb_device *udev = sd->gspca_dev.dev;
 	__u8 *buf = sd->gspca_dev.usb_buf;

 	/* No sensor with a data width larger than 16 bits has yet been seen */
 	if (len > sd->sensor->i2c_regW || !len)
 		return -EINVAL;

 	memcpy(buf, sensor_urb_skeleton,
 	       sizeof(sensor_urb_skeleton));

 	buf[11] = sd->sensor->i2c_slave_id;
 	buf[15] = address;

 	/* Special case larger sensor writes */
 	p = buf + 16;

 	/* Copy a four byte write sequence for each byte to be written to */
 	for (i = 0; i < len; i++) {
 		memcpy(p, sensor_urb_skeleton + 16, 4);
 		p[3] = i2c_data[i];
 		p += 4;
 		PDEBUG(D_CONF, "Writing sensor register 0x%x with 0x%x",
 		       address, i2c_data[i]);
 	}

 	/* Copy the tailer */
 	memcpy(p, sensor_urb_skeleton + 20, 4);

 	/* Set the total length */
 	p[3] = 0x10 + len;

 	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
 			      0x04, 0x40, 0x19,
 			      0x0000, buf,
 			      20 + len * 4, M5602_URB_MSG_TIMEOUT);

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

 /* Dump all the registers of the m5602 bridge,
    unfortunately this breaks the camera until it's power cycled */
 static void m5602_dump_bridge(struct sd *sd)
 {
 	int i;
 	for (i = 0; i < 0x80; i++) {
 		unsigned char val = 0;
 		m5602_read_bridge(sd, i, &val);
 		pr_info("ALi m5602 address 0x%x contains 0x%x\n", i, val);
 	}
 	pr_info("Warning: The ALi m5602 webcam probably won't work until it's power cycled\n");
 }

 static int m5602_probe_sensor(struct sd *sd)
 {
 	/* Try the po1030 */
 	sd->sensor = &po1030;
 	if (!sd->sensor->probe(sd))
 		return 0;

 	/* Try the mt9m111 sensor */
 	sd->sensor = &mt9m111;
 	if (!sd->sensor->probe(sd))
 		return 0;

 	/* Try the s5k4aa */
 	sd->sensor = &s5k4aa;
 	if (!sd->sensor->probe(sd))
 		return 0;

 	/* Try the ov9650 */
 	sd->sensor = &ov9650;
 	if (!sd->sensor->probe(sd))
 		return 0;

 	/* Try the ov7660 */
 	sd->sensor = &ov7660;
 	if (!sd->sensor->probe(sd))
 		return 0;

 	/* Try the s5k83a */
 	sd->sensor = &s5k83a;
 	if (!sd->sensor->probe(sd))
 		return 0;

 	/* More sensor probe function goes here */
 	pr_info("Failed to find a sensor\n");
 	sd->sensor = NULL;
 	return -ENODEV;
 }

 static int m5602_configure(struct gspca_dev *gspca_dev,
 			   const struct usb_device_id *id);

 static int m5602_init(struct gspca_dev *gspca_dev)
 {
 	struct sd *sd = (struct sd *) gspca_dev;
 	int err;

 	PDEBUG(D_CONF, "Initializing ALi m5602 webcam");
 	/* Run the init sequence */
 	err = sd->sensor->init(sd);

 	return err;
 }

 static int m5602_init_controls(struct gspca_dev *gspca_dev)
 {
 	struct sd *sd = (struct sd *) gspca_dev;

 	if (!sd->sensor->init_controls)
 		return 0;

 	return sd->sensor->init_controls(sd);
 }

 static int m5602_start_transfer(struct gspca_dev *gspca_dev)
 {
 	struct sd *sd = (struct sd *) gspca_dev;
 	__u8 *buf = sd->gspca_dev.usb_buf;
 	int err;

 	/* Send start command to the camera */
 	const u8 buffer[4] = {0x13, 0xf9, 0x0f, 0x01};

 	if (sd->sensor->start)
 		sd->sensor->start(sd);

 	memcpy(buf, buffer, sizeof(buffer));
 	err = usb_control_msg(gspca_dev->dev,
 			      usb_sndctrlpipe(gspca_dev->dev, 0),
 			      0x04, 0x40, 0x19, 0x0000, buf,
 			      sizeof(buffer), M5602_URB_MSG_TIMEOUT);

 	PDEBUG(D_STREAM, "Transfer started");
 	return (err < 0) ? err : 0;
 }

 static void m5602_urb_complete(struct gspca_dev *gspca_dev,
 				u8 *data, int len)
 {
 	struct sd *sd = (struct sd *) gspca_dev;

 	if (len < 6) {
 		PDEBUG(D_PACK, "Packet is less than 6 bytes");
 		return;
 	}

 	/* Frame delimiter: ff xx xx xx ff ff */
 	if (data[0] == 0xff && data[4] == 0xff && data[5] == 0xff &&
 	    data[2] != sd->frame_id) {
 		PDEBUG(D_FRAM, "Frame delimiter detected");
 		sd->frame_id = data[2];

 		/* Remove the extra fluff appended on each header */
 		data += 6;
 		len -= 6;

 		/* Complete the last frame (if any) */
 		gspca_frame_add(gspca_dev, LAST_PACKET,
 				NULL, 0);
 		sd->frame_count++;

 		/* Create a new frame */
 		gspca_frame_add(gspca_dev, FIRST_PACKET, data, len);

 		PDEBUG(D_FRAM, "Starting new frame %d",
 		       sd->frame_count);

 	} else {
 		int cur_frame_len;

 		cur_frame_len = gspca_dev->image_len;
 		/* Remove urb header */
 		data += 4;
 		len -= 4;

 		if (cur_frame_len + len <= gspca_dev->frsz) {
 			PDEBUG(D_FRAM, "Continuing frame %d copying %d bytes",
 			       sd->frame_count, len);

 			gspca_frame_add(gspca_dev, INTER_PACKET,
 					data, len);
 		} else {
 			/* Add the remaining data up to frame size */
 			gspca_frame_add(gspca_dev, INTER_PACKET, data,
 				    gspca_dev->frsz - cur_frame_len);
 		}
 	}
 }

 static void m5602_stop_transfer(struct gspca_dev *gspca_dev)
 {
 	struct sd *sd = (struct sd *) gspca_dev;

 	/* Run the sensor specific end transfer sequence */
 	if (sd->sensor->stop)
 		sd->sensor->stop(sd);
 }

 /* sub-driver description */
 static const struct sd_desc sd_desc = {
 	.name		= MODULE_NAME,
 	.config		= m5602_configure,
 	.init		= m5602_init,
 	.init_controls	= m5602_init_controls,
 	.start		= m5602_start_transfer,
 	.stopN		= m5602_stop_transfer,
 	.pkt_scan	= m5602_urb_complete
 };

 /* this function is called at probe time */
 static int m5602_configure(struct gspca_dev *gspca_dev,
 			   const struct usb_device_id *id)
 {
 	struct sd *sd = (struct sd *) gspca_dev;
 	struct cam *cam;
 	int err;

 	cam = &gspca_dev->cam;

 	if (dump_bridge)
 		m5602_dump_bridge(sd);

 	/* Probe sensor */
 	err = m5602_probe_sensor(sd);
 	if (err)
 		goto fail;

 	return 0;

 fail:
 	PERR("ALi m5602 webcam failed");
 	cam->cam_mode = NULL;
 	cam->nmodes = 0;

 	return err;
 }

 static int m5602_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 void m5602_disconnect(struct usb_interface *intf)
 {
 	struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
 	struct sd *sd = (struct sd *) gspca_dev;

 	if (sd->sensor->disconnect)
 		sd->sensor->disconnect(sd);

 	gspca_disconnect(intf);
 }

 static struct usb_driver sd_driver = {
 	.name = MODULE_NAME,
 	.id_table = m5602_table,
 	.probe = m5602_probe,
 #ifdef CONFIG_PM
 	.suspend = gspca_suspend,
 	.resume = gspca_resume,
 	.reset_resume = gspca_resume,
 #endif
 	.disconnect = m5602_disconnect
 };

 module_usb_driver(sd_driver);

 MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_LICENSE("GPL");
 module_param(force_sensor, int, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(force_sensor,
 		"forces detection of a sensor, "
 		"1 = OV9650, 2 = S5K83A, 3 = S5K4AA, "
 		"4 = MT9M111, 5 = PO1030, 6 = OV7660");

 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 usb sensor registers "
 		"at startup providing a sensor is found");
	/*
	* USB Driver for ALi m5602 based webcams
	*
	* Copyright (C) 2008 Erik Andrén
	* Copyright (C) 2007 Ilyes Gouta. Based on the m5603x Linux Driver Project.
	* Copyright (C) 2005 m5603x Linux Driver Project <m5602@x3ng.com.br>
	*
	* Portions of code to USB interface and ALi driver software,
	* Copyright (c) 2006 Willem Duinker
	* v4l2 interface modeled after the V4L2 driver
	* for SN9C10x PC Camera Controllers
	*
	* 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, version 2.
	*
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include "m5602_ov9650.h"
	#include "m5602_ov7660.h"
	#include "m5602_mt9m111.h"
	#include "m5602_po1030.h"
	#include "m5602_s5k83a.h"
	#include "m5602_s5k4aa.h"

	/* Kernel module parameters */
	int force_sensor;
	static bool dump_bridge;
	bool dump_sensor;

	static const struct usb_device_id m5602_table[] = {
	{USB_DEVICE(0x0402, 0x5602)},
	{}
	};

	MODULE_DEVICE_TABLE(usb, m5602_table);

	/* A skeleton used for sending messages to the sensor */
	static const unsigned char sensor_urb_skeleton[] = {
	0x23, M5602_XB_GPIO_EN_H, 0x81, 0x06,
	0x23, M5602_XB_MISC_CTRL, 0x81, 0x80,
	0x13, M5602_XB_I2C_DEV_ADDR, 0x81, 0x00,
	0x13, M5602_XB_I2C_REG_ADDR, 0x81, 0x00,
	0x13, M5602_XB_I2C_DATA, 0x81, 0x00,
	0x13, M5602_XB_I2C_CTRL, 0x81, 0x11
	};

	/* A skeleton used for sending messages to the m5602 bridge */
	static const unsigned char bridge_urb_skeleton[] = {
	0x13, 0x00, 0x81, 0x00
	};

	/* Reads a byte from the m5602 */
	int m5602_read_bridge(struct sd sd, const u8 address, u8 i2c_data)
	{
	int err;
	struct gspca_dev gspca_dev = (struct gspca_dev ) sd;
	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, 0x14,
	0x8100 + address, buf,
	1, M5602_URB_MSG_TIMEOUT);
	*i2c_data = buf[0];

	PDEBUG(D_CONF, "Reading bridge register 0x%x containing 0x%x",
	address, *i2c_data);

	/* usb_control_msg(...) returns the number of bytes sent upon success,
	mask that and return zero instead*/
	return (err < 0) ? err : 0;
	}

	/* Writes a byte to the m5602 */
	int m5602_write_bridge(struct sd *sd, const u8 address, const u8 i2c_data)
	{
	int err;
	struct gspca_dev gspca_dev = (struct gspca_dev ) sd;
	struct usb_device *udev = sd->gspca_dev.dev;
	__u8 *buf = sd->gspca_dev.usb_buf;

	PDEBUG(D_CONF, "Writing bridge register 0x%x with 0x%x",
	address, i2c_data);

	memcpy(buf, bridge_urb_skeleton,
	sizeof(bridge_urb_skeleton));
	buf[1] = address;
	buf[3] = i2c_data;

	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
	0x04, 0x40, 0x19,
	0x0000, buf,
	4, M5602_URB_MSG_TIMEOUT);

	/* usb_control_msg(...) returns the number of bytes sent upon success,
	mask that and return zero instead */
	return (err < 0) ? err : 0;
	}

	static int m5602_wait_for_i2c(struct sd *sd)
	{
	int err;
	u8 data;

	do {
	err = m5602_read_bridge(sd, M5602_XB_I2C_STATUS, &data);
	} while ((data & I2C_BUSY) && !err);
	return err;
	}

	int m5602_read_sensor(struct sd *sd, const u8 address,
	u8 *i2c_data, const u8 len)
	{
	int err, i;
	struct gspca_dev gspca_dev = (struct gspca_dev ) sd;

	if (!len \|\| len > sd->sensor->i2c_regW)
	return -EINVAL;

	err = m5602_wait_for_i2c(sd);
	if (err < 0)
	return err;

	err = m5602_write_bridge(sd, M5602_XB_I2C_DEV_ADDR,
	sd->sensor->i2c_slave_id);
	if (err < 0)
	return err;

	err = m5602_write_bridge(sd, M5602_XB_I2C_REG_ADDR, address);
	if (err < 0)
	return err;

	/* Sensors with registers that are of only
	one byte width are differently read */

	/* FIXME: This works with the ov9650, but has issues with the po1030 */
	if (sd->sensor->i2c_regW == 1) {
	err = m5602_write_bridge(sd, M5602_XB_I2C_CTRL, 1);
	if (err < 0)
	return err;

	err = m5602_write_bridge(sd, M5602_XB_I2C_CTRL, 0x08);
	} else {
	err = m5602_write_bridge(sd, M5602_XB_I2C_CTRL, 0x18 + len);
	}

	for (i = 0; (i < len) && !err; i++) {
	err = m5602_wait_for_i2c(sd);
	if (err < 0)
	return err;

	err = m5602_read_bridge(sd, M5602_XB_I2C_DATA, &(i2c_data[i]));

	PDEBUG(D_CONF, "Reading sensor register "
	"0x%x containing 0x%x ", address, *i2c_data);
	}
	return err;
	}

	int m5602_write_sensor(struct sd *sd, const u8 address,
	u8 *i2c_data, const u8 len)
	{
	int err, i;
	u8 *p;
	struct gspca_dev gspca_dev = (struct gspca_dev ) sd;
	struct usb_device *udev = sd->gspca_dev.dev;
	__u8 *buf = sd->gspca_dev.usb_buf;

	/* No sensor with a data width larger than 16 bits has yet been seen */
	if (len > sd->sensor->i2c_regW \|\| !len)
	return -EINVAL;

	memcpy(buf, sensor_urb_skeleton,
	sizeof(sensor_urb_skeleton));

	buf[11] = sd->sensor->i2c_slave_id;
	buf[15] = address;

	/* Special case larger sensor writes */
	p = buf + 16;

	/* Copy a four byte write sequence for each byte to be written to */
	for (i = 0; i < len; i++) {
	memcpy(p, sensor_urb_skeleton + 16, 4);
	p[3] = i2c_data[i];
	p += 4;
	PDEBUG(D_CONF, "Writing sensor register 0x%x with 0x%x",
	address, i2c_data[i]);
	}

	/* Copy the tailer */
	memcpy(p, sensor_urb_skeleton + 20, 4);

	/* Set the total length */
	p[3] = 0x10 + len;

	err = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
	0x04, 0x40, 0x19,
	0x0000, buf,
	20 + len * 4, M5602_URB_MSG_TIMEOUT);

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

	/* Dump all the registers of the m5602 bridge,
	unfortunately this breaks the camera until it's power cycled */
	static void m5602_dump_bridge(struct sd *sd)
	{
	int i;
	for (i = 0; i < 0x80; i++) {
	unsigned char val = 0;
	m5602_read_bridge(sd, i, &val);
	pr_info("ALi m5602 address 0x%x contains 0x%x\n", i, val);
	}
	pr_info("Warning: The ALi m5602 webcam probably won't work until it's power cycled\n");
	}

	static int m5602_probe_sensor(struct sd *sd)
	{
	/* Try the po1030 */
	sd->sensor = &po1030;
	if (!sd->sensor->probe(sd))
	return 0;

	/* Try the mt9m111 sensor */
	sd->sensor = &mt9m111;
	if (!sd->sensor->probe(sd))
	return 0;

	/* Try the s5k4aa */
	sd->sensor = &s5k4aa;
	if (!sd->sensor->probe(sd))
	return 0;

	/* Try the ov9650 */
	sd->sensor = &ov9650;
	if (!sd->sensor->probe(sd))
	return 0;

	/* Try the ov7660 */
	sd->sensor = &ov7660;
	if (!sd->sensor->probe(sd))
	return 0;

	/* Try the s5k83a */
	sd->sensor = &s5k83a;
	if (!sd->sensor->probe(sd))
	return 0;

	/* More sensor probe function goes here */
	pr_info("Failed to find a sensor\n");
	sd->sensor = NULL;
	return -ENODEV;
	}

	static int m5602_configure(struct gspca_dev *gspca_dev,
	const struct usb_device_id *id);

	static int m5602_init(struct gspca_dev *gspca_dev)
	{
	struct sd sd = (struct sd ) gspca_dev;
	int err;

	PDEBUG(D_CONF, "Initializing ALi m5602 webcam");
	/* Run the init sequence */
	err = sd->sensor->init(sd);

	return err;
	}

	static int m5602_init_controls(struct gspca_dev *gspca_dev)
	{
	struct sd sd = (struct sd ) gspca_dev;

	if (!sd->sensor->init_controls)
	return 0;

	return sd->sensor->init_controls(sd);
	}

	static int m5602_start_transfer(struct gspca_dev *gspca_dev)
	{
	struct sd sd = (struct sd ) gspca_dev;
	__u8 *buf = sd->gspca_dev.usb_buf;
	int err;

	/* Send start command to the camera */
	const u8 buffer[4] = {0x13, 0xf9, 0x0f, 0x01};

	if (sd->sensor->start)
	sd->sensor->start(sd);

	memcpy(buf, buffer, sizeof(buffer));
	err = usb_control_msg(gspca_dev->dev,
	usb_sndctrlpipe(gspca_dev->dev, 0),
	0x04, 0x40, 0x19, 0x0000, buf,
	sizeof(buffer), M5602_URB_MSG_TIMEOUT);

	PDEBUG(D_STREAM, "Transfer started");
	return (err < 0) ? err : 0;
	}

	static void m5602_urb_complete(struct gspca_dev *gspca_dev,
	u8 *data, int len)
	{
	struct sd sd = (struct sd ) gspca_dev;

	if (len < 6) {
	PDEBUG(D_PACK, "Packet is less than 6 bytes");
	return;
	}

	/* Frame delimiter: ff xx xx xx ff ff */
	if (data[0] == 0xff && data[4] == 0xff && data[5] == 0xff &&
	data[2] != sd->frame_id) {
	PDEBUG(D_FRAM, "Frame delimiter detected");
	sd->frame_id = data[2];

	/* Remove the extra fluff appended on each header */
	data += 6;
	len -= 6;

	/* Complete the last frame (if any) */
	gspca_frame_add(gspca_dev, LAST_PACKET,
	NULL, 0);
	sd->frame_count++;

	/* Create a new frame */
	gspca_frame_add(gspca_dev, FIRST_PACKET, data, len);

	PDEBUG(D_FRAM, "Starting new frame %d",
	sd->frame_count);

	} else {
	int cur_frame_len;

	cur_frame_len = gspca_dev->image_len;
	/* Remove urb header */
	data += 4;
	len -= 4;

	if (cur_frame_len + len <= gspca_dev->frsz) {
	PDEBUG(D_FRAM, "Continuing frame %d copying %d bytes",
	sd->frame_count, len);

	gspca_frame_add(gspca_dev, INTER_PACKET,
	data, len);
	} else {
	/* Add the remaining data up to frame size */
	gspca_frame_add(gspca_dev, INTER_PACKET, data,
	gspca_dev->frsz - cur_frame_len);
	}
	}
	}

	static void m5602_stop_transfer(struct gspca_dev *gspca_dev)
	{
	struct sd sd = (struct sd ) gspca_dev;

	/* Run the sensor specific end transfer sequence */
	if (sd->sensor->stop)
	sd->sensor->stop(sd);
	}

	/* sub-driver description */
	static const struct sd_desc sd_desc = {
	.name = MODULE_NAME,
	.config = m5602_configure,
	.init = m5602_init,
	.init_controls = m5602_init_controls,
	.start = m5602_start_transfer,
	.stopN = m5602_stop_transfer,
	.pkt_scan = m5602_urb_complete
	};

	/* this function is called at probe time */
	static int m5602_configure(struct gspca_dev *gspca_dev,
	const struct usb_device_id *id)
	{
	struct sd sd = (struct sd ) gspca_dev;
	struct cam *cam;
	int err;

	cam = &gspca_dev->cam;

	if (dump_bridge)
	m5602_dump_bridge(sd);

	/* Probe sensor */
	err = m5602_probe_sensor(sd);
	if (err)
	goto fail;

	return 0;

	fail:
	PERR("ALi m5602 webcam failed");
	cam->cam_mode = NULL;
	cam->nmodes = 0;

	return err;
	}

	static int m5602_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 void m5602_disconnect(struct usb_interface *intf)
	{
	struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
	struct sd sd = (struct sd ) gspca_dev;

	if (sd->sensor->disconnect)
	sd->sensor->disconnect(sd);

	gspca_disconnect(intf);
	}

	static struct usb_driver sd_driver = {
	.name = MODULE_NAME,
	.id_table = m5602_table,
	.probe = m5602_probe,
	#ifdef CONFIG_PM
	.suspend = gspca_suspend,
	.resume = gspca_resume,
	.reset_resume = gspca_resume,
	#endif
	.disconnect = m5602_disconnect
	};

	module_usb_driver(sd_driver);

	MODULE_AUTHOR(DRIVER_AUTHOR);
	MODULE_DESCRIPTION(DRIVER_DESC);
	MODULE_LICENSE("GPL");
	module_param(force_sensor, int, S_IRUGO \| S_IWUSR);
	MODULE_PARM_DESC(force_sensor,
	"forces detection of a sensor, "
	"1 = OV9650, 2 = S5K83A, 3 = S5K4AA, "
	"4 = MT9M111, 5 = PO1030, 6 = OV7660");

	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 usb sensor registers "
	"at startup providing a sensor is found");