linux/drivers/media/usb/gspca/touptek.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * ToupTek UCMOS / AmScope MU series camera driver
 * TODO: contrast with ScopeTek / AmScope MDC cameras
 *
 * Copyright (C) 2012-2014 John McMaster <[email protected]>
 *
 * Special thanks to Bushing for helping with the decrypt algorithm and
 * Sean O'Sullivan / the Rensselaer Center for Open Source
 * Software (RCOS) for helping me learn kernel development
 */

#include "gspca.h"

#define MODULE_NAME "touptek"

MODULE_AUTHOR("John McMaster");
MODULE_DESCRIPTION("ToupTek UCMOS / Amscope MU microscope camera driver");
MODULE_LICENSE("GPL");

/*
 * Exposure reg is linear with exposure time
 * Exposure (sec), E (reg)
 * 0.000400, 0x0002
 * 0.001000, 0x0005
 * 0.005000, 0x0019
 * 0.020000, 0x0064
 * 0.080000, 0x0190
 * 0.400000, 0x07D0
 * 1.000000, 0x1388
 * 2.000000, 0x2710
 *
 * Three gain stages
 * 0x1000: master channel enable bit
 * 0x007F: low gain bits
 * 0x0080: medium gain bit
 * 0x0100: high gain bit
 * gain = enable * (1 + regH) * (1 + regM) * z * regL
 *
 * Gain implementation
 * Want to do something similar to mt9v011.c's set_balance
 *
 * Gain does not vary with resolution (checked 640x480 vs 1600x1200)
 *
 * Constant derivation:
 *
 * Raw data:
 * Gain,   GTOP,   B,	  R,	  GBOT
 * 1.00,   0x105C, 0x1068, 0x10C8, 0x105C
 * 1.20,   0x106E, 0x107E, 0x10D6, 0x106E
 * 1.40,   0x10C0, 0x10CA, 0x10E5, 0x10C0
 * 1.60,   0x10C9, 0x10D4, 0x10F3, 0x10C9
 * 1.80,   0x10D2, 0x10DE, 0x11C1, 0x10D2
 * 2.00,   0x10DC, 0x10E9, 0x11C8, 0x10DC
 * 2.20,   0x10E5, 0x10F3, 0x11CF, 0x10E5
 * 2.40,   0x10EE, 0x10FE, 0x11D7, 0x10EE
 * 2.60,   0x10F7, 0x11C4, 0x11DE, 0x10F7
 * 2.80,   0x11C0, 0x11CA, 0x11E5, 0x11C0
 * 3.00,   0x11C5, 0x11CF, 0x11ED, 0x11C5
 *
 * zR = 0.0069605943152454778
 *	about 3/431 = 0.0069605568445475635
 * zB = 0.0095695970695970703
 *	about 6/627 = 0.0095693779904306216
 * zG = 0.010889328063241107
 *	about 6/551 = 0.010889292196007259
 * about 10 bits for constant + 7 bits for value => at least 17 bit
 * intermediate with 32 bit ints should be fine for overflow etc
 * Essentially gains are in range 0-0x001FF
 *
 * However, V4L expects a main gain channel + R and B balance
 * To keep things simple for now saturate the values of balance is too high/low
 * This isn't really ideal but easy way to fit the Linux model
 *
 * Converted using gain model turns out to be quite linear:
 * Gain, GTOP, B, R, GBOT
 * 1.00, 92, 104, 144, 92
 * 1.20, 110, 126, 172, 110
 * 1.40, 128, 148, 202, 128
 * 1.60, 146, 168, 230, 146
 * 1.80, 164, 188, 260, 164
 * 2.00, 184, 210, 288, 184
 * 2.20, 202, 230, 316, 202
 * 2.40, 220, 252, 348, 220
 * 2.60, 238, 272, 376, 238
 * 2.80, 256, 296, 404, 256
 * 3.00, 276, 316, 436, 276
 *
 * Maximum gain is 0x7FF * 2 * 2 => 0x1FFC (8188)
 * or about 13 effective bits of gain
 * The highest the commercial driver goes in my setup 436
 * However, because could *maybe* damage circuits
 * limit the gain until have a reason to go higher
 * Solution: gain clipped and warning emitted
 */
#define GAIN_MAX		511

/* Frame sync is a short read */
#define BULK_SIZE		0x4000

/* MT9E001 reg names to give a rough approximation */
#define REG_COARSE_INTEGRATION_TIME_	0x3012
#define REG_GROUPED_PARAMETER_HOLD_	0x3022
#define REG_MODE_SELECT			0x0100
#define REG_OP_SYS_CLK_DIV		0x030A
#define REG_VT_SYS_CLK_DIV		0x0302
#define REG_PRE_PLL_CLK_DIV		0x0304
#define REG_VT_PIX_CLK_DIV		0x0300
#define REG_OP_PIX_CLK_DIV		0x0308
#define REG_PLL_MULTIPLIER		0x0306
#define REG_COARSE_INTEGRATION_TIME_	0x3012
#define REG_FRAME_LENGTH_LINES		0x0340
#define REG_FRAME_LENGTH_LINES_		0x300A
#define REG_GREEN1_GAIN			0x3056
#define REG_GREEN2_GAIN			0x305C
#define REG_GROUPED_PARAMETER_HOLD	0x0104
#define REG_LINE_LENGTH_PCK_		0x300C
#define REG_MODE_SELECT			0x0100
#define REG_PLL_MULTIPLIER		0x0306
#define REG_READ_MODE			0x3040
#define REG_BLUE_GAIN			0x3058
#define REG_RED_GAIN			0x305A
#define REG_RESET_REGISTER		0x301A
#define REG_SCALE_M			0x0404
#define REG_SCALING_MODE		0x0400
#define REG_SOFTWARE_RESET		0x0103
#define REG_X_ADDR_END			0x0348
#define REG_X_ADDR_START		0x0344
#define REG_X_ADDR_START		0x0344
#define REG_X_OUTPUT_SIZE		0x034C
#define REG_Y_ADDR_END			0x034A
#define REG_Y_ADDR_START		0x0346
#define REG_Y_OUTPUT_SIZE		0x034E


/* specific webcam descriptor */
struct sd {
	struct gspca_dev gspca_dev;	/* !! must be the first item */
	/* How many bytes this frame */
	unsigned int this_f;

	/*
	Device has separate gains for each Bayer quadrant
	V4L supports master gain which is referenced to G1/G2 and supplies
	individual balance controls for R/B
	*/
	struct v4l2_ctrl *blue;
	struct v4l2_ctrl *red;
};

/* Used to simplify reg write error handling */
struct cmd {
	u16 value;
	u16 index;
};

static const struct v4l2_pix_format vga_mode[] = {
	{800, 600,
		V4L2_PIX_FMT_SGRBG8,
		V4L2_FIELD_NONE,
		.bytesperline = 800,
		.sizeimage = 800 * 600,
		.colorspace = V4L2_COLORSPACE_SRGB},
	{1600, 1200,
		V4L2_PIX_FMT_SGRBG8,
		V4L2_FIELD_NONE,
		.bytesperline = 1600,
		.sizeimage = 1600 * 1200,
		.colorspace = V4L2_COLORSPACE_SRGB},
	{3264, 2448,
		V4L2_PIX_FMT_SGRBG8,
		V4L2_FIELD_NONE,
		.bytesperline = 3264,
		.sizeimage = 3264 * 2448,
		.colorspace = V4L2_COLORSPACE_SRGB},
};

/*
 * As there's no known frame sync, the only way to keep synced is to try hard
 * to never miss any packets
 */
#if MAX_NURBS < 4
#error "Not enough URBs in the gspca table"
#endif

static int val_reply(struct gspca_dev *gspca_dev, const char *reply, int rc)
{
	if (rc < 0) {
		gspca_err(gspca_dev, "reply has error %d\n", rc);
		return -EIO;
	}
	if (rc != 1) {
		gspca_err(gspca_dev, "Bad reply size %d\n", rc);
		return -EIO;
	}
	if (reply[0] != 0x08) {
		gspca_err(gspca_dev, "Bad reply 0x%02x\n", (int)reply[0]);
		return -EIO;
	}
	return 0;
}

static void reg_w(struct gspca_dev *gspca_dev, u16 value, u16 index)
{
	char *buff = gspca_dev->usb_buf;
	int rc;

	gspca_dbg(gspca_dev, D_USBO,
		  "reg_w bReq=0x0B, bReqT=0xC0, wVal=0x%04X, wInd=0x%04X\n\n",
		  value, index);
	rc = usb_control_msg(gspca_dev->dev, usb_rcvctrlpipe(gspca_dev->dev, 0),
		0x0B, 0xC0, value, index, buff, 1, 500);
	gspca_dbg(gspca_dev, D_USBO, "rc=%d, ret={0x%02x}\n", rc, (int)buff[0]);
	if (rc < 0) {
		gspca_err(gspca_dev, "Failed reg_w(0x0B, 0xC0, 0x%04X, 0x%04X) w/ rc %d\n",
			  value, index, rc);
		gspca_dev->usb_err = rc;
		return;
	}
	if (val_reply(gspca_dev, buff, rc)) {
		gspca_err(gspca_dev, "Bad reply to reg_w(0x0B, 0xC0, 0x%04X, 0x%04X\n",
			  value, index);
		gspca_dev->usb_err = -EIO;
	}
}

static void reg_w_buf(struct gspca_dev *gspca_dev,
		const struct cmd *p, int l)
{
	do {
		reg_w(gspca_dev, p->value, p->index);
		p++;
	} while (--l > 0);
}

static void setexposure(struct gspca_dev *gspca_dev, s32 val)
{
	u16 value;
	unsigned int w = gspca_dev->pixfmt.width;

	if (w == 800)
		value = val * 5;
	else if (w == 1600)
		value = val * 3;
	else if (w == 3264)
		value = val * 3 / 2;
	else {
		gspca_err(gspca_dev, "Invalid width %u\n", w);
		gspca_dev->usb_err = -EINVAL;
		return;
	}
	gspca_dbg(gspca_dev, D_STREAM, "exposure: 0x%04X ms\n\n", value);
	/* Wonder if there's a good reason for sending it twice */
	/* probably not but leave it in because...why not */
	reg_w(gspca_dev, value, REG_COARSE_INTEGRATION_TIME_);
	reg_w(gspca_dev, value, REG_COARSE_INTEGRATION_TIME_);
}

static int gainify(int in)
{
	/*
	 * TODO: check if there are any issues with corner cases
	 * 0x000 (0):0x07F (127): regL
	 * 0x080 (128) - 0x0FF (255): regM, regL
	 * 0x100 (256) - max: regH, regM, regL
	 */
	if (in <= 0x7F)
		return 0x1000 | in;
	else if (in <= 0xFF)
		return 0x1080 | in / 2;
	else
		return 0x1180 | in / 4;
}

static void setggain(struct gspca_dev *gspca_dev, u16 global_gain)
{
	u16 normalized;

	normalized = gainify(global_gain);
	gspca_dbg(gspca_dev, D_STREAM, "gain G1/G2 (0x%04X): 0x%04X (src 0x%04X)\n\n",
		  REG_GREEN1_GAIN,
		  normalized, global_gain);

	reg_w(gspca_dev, normalized, REG_GREEN1_GAIN);
	reg_w(gspca_dev, normalized, REG_GREEN2_GAIN);
}

static void setbgain(struct gspca_dev *gspca_dev,
		u16 gain, u16 global_gain)
{
	u16 normalized;

	normalized = global_gain +
		((u32)global_gain) * gain / GAIN_MAX;
	if (normalized > GAIN_MAX) {
		gspca_dbg(gspca_dev, D_STREAM, "Truncating blue 0x%04X w/ value 0x%04X\n\n",
			  GAIN_MAX, normalized);
		normalized = GAIN_MAX;
	}
	normalized = gainify(normalized);
	gspca_dbg(gspca_dev, D_STREAM, "gain B (0x%04X): 0x%04X w/ source 0x%04X\n\n",
		  REG_BLUE_GAIN, normalized, gain);

	reg_w(gspca_dev, normalized, REG_BLUE_GAIN);
}

static void setrgain(struct gspca_dev *gspca_dev,
		u16 gain, u16 global_gain)
{
	u16 normalized;

	normalized = global_gain +
		((u32)global_gain) * gain / GAIN_MAX;
	if (normalized > GAIN_MAX) {
		gspca_dbg(gspca_dev, D_STREAM, "Truncating gain 0x%04X w/ value 0x%04X\n\n",
			  GAIN_MAX, normalized);
		normalized = GAIN_MAX;
	}
	normalized = gainify(normalized);
	gspca_dbg(gspca_dev, D_STREAM, "gain R (0x%04X): 0x%04X w / source 0x%04X\n\n",
		  REG_RED_GAIN, normalized, gain);

	reg_w(gspca_dev, normalized, REG_RED_GAIN);
}

static void configure_wh(struct gspca_dev *gspca_dev)
{
	unsigned int w = gspca_dev->pixfmt.width;

	gspca_dbg(gspca_dev, D_STREAM, "configure_wh\n\n");

	if (w == 800) {
		static const struct cmd reg_init_res[] = {
			{0x0060, REG_X_ADDR_START},
			{0x0CD9, REG_X_ADDR_END},
			{0x0036, REG_Y_ADDR_START},
			{0x098F, REG_Y_ADDR_END},
			{0x07C7, REG_READ_MODE},
		};

		reg_w_buf(gspca_dev,
			       reg_init_res, ARRAY_SIZE(reg_init_res));
	} else if (w == 1600) {
		static const struct cmd reg_init_res[] = {
			{0x009C, REG_X_ADDR_START},
			{0x0D19, REG_X_ADDR_END},
			{0x0068, REG_Y_ADDR_START},
			{0x09C5, REG_Y_ADDR_END},
			{0x06C3, REG_READ_MODE},
		};

		reg_w_buf(gspca_dev,
			       reg_init_res, ARRAY_SIZE(reg_init_res));
	} else if (w == 3264) {
		static const struct cmd reg_init_res[] = {
			{0x00E8, REG_X_ADDR_START},
			{0x0DA7, REG_X_ADDR_END},
			{0x009E, REG_Y_ADDR_START},
			{0x0A2D, REG_Y_ADDR_END},
			{0x0241, REG_READ_MODE},
		};

		reg_w_buf(gspca_dev,
			       reg_init_res, ARRAY_SIZE(reg_init_res));
	} else {
		gspca_err(gspca_dev, "bad width %u\n", w);
		gspca_dev->usb_err = -EINVAL;
		return;
	}

	reg_w(gspca_dev, 0x0000, REG_SCALING_MODE);
	reg_w(gspca_dev, 0x0010, REG_SCALE_M);
	reg_w(gspca_dev, w, REG_X_OUTPUT_SIZE);
	reg_w(gspca_dev, gspca_dev->pixfmt.height, REG_Y_OUTPUT_SIZE);

	if (w == 800) {
		reg_w(gspca_dev, 0x0384, REG_FRAME_LENGTH_LINES_);
		reg_w(gspca_dev, 0x0960, REG_LINE_LENGTH_PCK_);
	} else if (w == 1600) {
		reg_w(gspca_dev, 0x0640, REG_FRAME_LENGTH_LINES_);
		reg_w(gspca_dev, 0x0FA0, REG_LINE_LENGTH_PCK_);
	} else if (w == 3264) {
		reg_w(gspca_dev, 0x0B4B, REG_FRAME_LENGTH_LINES_);
		reg_w(gspca_dev, 0x1F40, REG_LINE_LENGTH_PCK_);
	} else {
		gspca_err(gspca_dev, "bad width %u\n", w);
		gspca_dev->usb_err = -EINVAL;
		return;
	}
}

/* Packets that were encrypted, no idea if the grouping is significant */
static void configure_encrypted(struct gspca_dev *gspca_dev)
{
	static const struct cmd reg_init_begin[] = {
		{0x0100, REG_SOFTWARE_RESET},
		{0x0000, REG_MODE_SELECT},
		{0x0100, REG_GROUPED_PARAMETER_HOLD},
		{0x0004, REG_VT_PIX_CLK_DIV},
		{0x0001, REG_VT_SYS_CLK_DIV},
		{0x0008, REG_OP_PIX_CLK_DIV},
		{0x0001, REG_OP_SYS_CLK_DIV},
		{0x0004, REG_PRE_PLL_CLK_DIV},
		{0x0040, REG_PLL_MULTIPLIER},
		{0x0000, REG_GROUPED_PARAMETER_HOLD},
		{0x0100, REG_GROUPED_PARAMETER_HOLD},
	};
	static const struct cmd reg_init_end[] = {
		{0x0000, REG_GROUPED_PARAMETER_HOLD},
		{0x0301, 0x31AE},
		{0x0805, 0x3064},
		{0x0071, 0x3170},
		{0x10DE, REG_RESET_REGISTER},
		{0x0000, REG_MODE_SELECT},
		{0x0010, REG_PLL_MULTIPLIER},
		{0x0100, REG_MODE_SELECT},
	};

	gspca_dbg(gspca_dev, D_STREAM, "Encrypted begin, w = %u\n\n",
		  gspca_dev->pixfmt.width);
	reg_w_buf(gspca_dev, reg_init_begin, ARRAY_SIZE(reg_init_begin));
	configure_wh(gspca_dev);
	reg_w_buf(gspca_dev, reg_init_end, ARRAY_SIZE(reg_init_end));
	reg_w(gspca_dev, 0x0100, REG_GROUPED_PARAMETER_HOLD);
	reg_w(gspca_dev, 0x0000, REG_GROUPED_PARAMETER_HOLD);

	gspca_dbg(gspca_dev, D_STREAM, "Encrypted end\n\n");
}

static int configure(struct gspca_dev *gspca_dev)
{
	int rc;
	char *buff = gspca_dev->usb_buf;

	gspca_dbg(gspca_dev, D_STREAM, "configure()\n\n");

	/*
	 * First driver sets a sort of encryption key
	 * A number of futur requests of this type have wValue and wIndex
	 * encrypted as follows:
	 * -Compute key = this wValue rotate left by 4 bits
	 *	(decrypt.py rotates right because we are decrypting)
	 * -Later packets encrypt packets by XOR'ing with key
	 *	XOR encrypt/decrypt is symmetrical
	 *	wValue, and wIndex are encrypted
	 *	bRequest is not and bRequestType is always 0xC0
	 *		This allows resyncing if key is unknown?
	 * By setting 0 we XOR with 0 and the shifting and XOR drops out
	 */
	rc = usb_control_msg(gspca_dev->dev, usb_rcvctrlpipe(gspca_dev->dev, 0),
			     0x16, 0xC0, 0x0000, 0x0000, buff, 2, 500);
	if (val_reply(gspca_dev, buff, rc)) {
		gspca_err(gspca_dev, "failed key req\n");
		return -EIO;
	}

	/*
	 * Next does some sort of 2 packet challenge / response
	 * evidence suggests its an Atmel I2C crypto part but nobody cares to
	 * look
	 * (to make sure its not cloned hardware?)
	 * Ignore: I want to work with their hardware, not clone it
	 * 16 bytes out challenge, requestType: 0x40
	 * 16 bytes in response, requestType: 0xC0
	 */

	rc = usb_control_msg(gspca_dev->dev, usb_sndctrlpipe(gspca_dev->dev, 0),
			     0x01, 0x40, 0x0001, 0x000F, NULL, 0, 500);
	if (rc < 0) {
		gspca_err(gspca_dev, "failed to replay packet 176 w/ rc %d\n",
			  rc);
		return rc;
	}

	rc = usb_control_msg(gspca_dev->dev, usb_sndctrlpipe(gspca_dev->dev, 0),
			     0x01, 0x40, 0x0000, 0x000F, NULL, 0, 500);
	if (rc < 0) {
		gspca_err(gspca_dev, "failed to replay packet 178 w/ rc %d\n",
			  rc);
		return rc;
	}

	rc = usb_control_msg(gspca_dev->dev, usb_sndctrlpipe(gspca_dev->dev, 0),
			     0x01, 0x40, 0x0001, 0x000F, NULL, 0, 500);
	if (rc < 0) {
		gspca_err(gspca_dev, "failed to replay packet 180 w/ rc %d\n",
			  rc);
		return rc;
	}

	/*
	 * Serial number?  Doesn't seem to be required
	 * cam1: \xE6\x0D\x00\x00, cam2: \x70\x19\x00\x00
	 * rc = usb_control_msg(gspca_dev->dev,
	 *			usb_rcvctrlpipe(gspca_dev->dev, 0),
	 *			0x20, 0xC0, 0x0000, 0x0000, buff, 4, 500);
	 */

	/* Large (EEPROM?) read, skip it since no idea what to do with it */
	gspca_dev->usb_err = 0;
	configure_encrypted(gspca_dev);
	if (gspca_dev->usb_err)
		return gspca_dev->usb_err;

	/* Omitted this by accident, does not work without it */
	rc = usb_control_msg(gspca_dev->dev, usb_sndctrlpipe(gspca_dev->dev, 0),
			     0x01, 0x40, 0x0003, 0x000F, NULL, 0, 500);
	if (rc < 0) {
		gspca_err(gspca_dev, "failed to replay final packet w/ rc %d\n",
			  rc);
		return rc;
	}

	gspca_dbg(gspca_dev, D_STREAM, "Configure complete\n\n");
	return 0;
}

static int sd_config(struct gspca_dev *gspca_dev,
		     const struct usb_device_id *id)
{
	gspca_dev->cam.cam_mode = vga_mode;
	gspca_dev->cam.nmodes = ARRAY_SIZE(vga_mode);

	/* Yes we want URBs and we want them now! */
	gspca_dev->cam.no_urb_create = 0;
	gspca_dev->cam.bulk_nurbs = 4;
	/* Largest size the windows driver uses */
	gspca_dev->cam.bulk_size = BULK_SIZE;
	/* Def need to use bulk transfers */
	gspca_dev->cam.bulk = 1;

	return 0;
}

static int sd_start(struct gspca_dev *gspca_dev)
{
	struct sd *sd = (struct sd *) gspca_dev;
	int rc;

	sd->this_f = 0;

	rc = configure(gspca_dev);
	if (rc < 0) {
		gspca_err(gspca_dev, "Failed configure\n");
		return rc;
	}
	/* First two frames have messed up gains
	Drop them to avoid special cases in user apps? */
	return 0;
}

static void sd_pkt_scan(struct gspca_dev *gspca_dev,
			u8 *data,	/* isoc packet */
			int len)	/* iso packet length */
{
	struct sd *sd = (struct sd *) gspca_dev;

	if (len != BULK_SIZE) {
		/* can we finish a frame? */
		if (sd->this_f + len == gspca_dev->pixfmt.sizeimage) {
			gspca_frame_add(gspca_dev, LAST_PACKET, data, len);
			gspca_dbg(gspca_dev, D_FRAM, "finish frame sz %u/%u w/ len %u\n\n",
				  sd->this_f, gspca_dev->pixfmt.sizeimage, len);
		/* lost some data, discard the frame */
		} else {
			gspca_frame_add(gspca_dev, DISCARD_PACKET, NULL, 0);
			gspca_dbg(gspca_dev, D_FRAM, "abort frame sz %u/%u w/ len %u\n\n",
				  sd->this_f, gspca_dev->pixfmt.sizeimage, len);
		}
		sd->this_f = 0;
	} else {
		if (sd->this_f == 0)
			gspca_frame_add(gspca_dev, FIRST_PACKET, data, len);
		else
			gspca_frame_add(gspca_dev, INTER_PACKET, data, len);
		sd->this_f += len;
	}
}

static int sd_init(struct gspca_dev *gspca_dev)
{
	return 0;
}

static int sd_s_ctrl(struct v4l2_ctrl *ctrl)
{
	struct gspca_dev *gspca_dev =
		container_of(ctrl->handler, struct gspca_dev, ctrl_handler);
	struct sd *sd = (struct sd *) gspca_dev;

	gspca_dev->usb_err = 0;

	if (!gspca_dev->streaming)
		return 0;

	switch (ctrl->id) {
	case V4L2_CID_EXPOSURE:
		setexposure(gspca_dev, ctrl->val);
		break;
	case V4L2_CID_GAIN:
		/* gspca_dev->gain automatically updated */
		setggain(gspca_dev, gspca_dev->gain->val);
		break;
	case V4L2_CID_BLUE_BALANCE:
		sd->blue->val = ctrl->val;
		setbgain(gspca_dev, sd->blue->val, gspca_dev->gain->val);
		break;
	case V4L2_CID_RED_BALANCE:
		sd->red->val = ctrl->val;
		setrgain(gspca_dev, sd->red->val, gspca_dev->gain->val);
		break;
	}
	return gspca_dev->usb_err;
}

static const struct v4l2_ctrl_ops sd_ctrl_ops = {
	.s_ctrl = sd_s_ctrl,
};

static int sd_init_controls(struct gspca_dev *gspca_dev)
{
	struct sd *sd = (struct sd *) gspca_dev;
	struct v4l2_ctrl_handler *hdl = &gspca_dev->ctrl_handler;

	gspca_dev->vdev.ctrl_handler = hdl;
	v4l2_ctrl_handler_init(hdl, 4);

	gspca_dev->exposure = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
	/* Mostly limited by URB timeouts */
	/* XXX: make dynamic based on frame rate? */
		V4L2_CID_EXPOSURE, 0, 800, 1, 350);
	gspca_dev->gain = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
			V4L2_CID_GAIN, 0, 511, 1, 128);
	sd->blue = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
			V4L2_CID_BLUE_BALANCE, 0, 1023, 1, 80);
	sd->red = v4l2_ctrl_new_std(hdl, &sd_ctrl_ops,
			V4L2_CID_RED_BALANCE, 0, 1023, 1, 295);

	if (hdl->error) {
		gspca_err(gspca_dev, "Could not initialize controls\n");
		return hdl->error;
	}
	return 0;
}

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

/* Table of supported USB devices */
static const struct usb_device_id device_table[] = {
	/* Commented out devices should be related */
	/* AS: AmScope, TT: ToupTek */
	/* { USB_DEVICE(0x0547, 0x6035) },  TT UCMOS00350KPA */
	/* { USB_DEVICE(0x0547, 0x6130) },  TT UCMOS01300KPA */
	/* { USB_DEVICE(0x0547, 0x6200) },  TT UCMOS02000KPA */
	/* { USB_DEVICE(0x0547, 0x6310) },  TT UCMOS03100KPA */
	/* { USB_DEVICE(0x0547, 0x6510) },  TT UCMOS05100KPA */
	/* { USB_DEVICE(0x0547, 0x6800) },  TT UCMOS08000KPA */
	/* { USB_DEVICE(0x0547, 0x6801) },  TT UCMOS08000KPB */
	{ USB_DEVICE(0x0547, 0x6801) }, /* TT UCMOS08000KPB, AS MU800 */
	/* { USB_DEVICE(0x0547, 0x6900) },  TT UCMOS09000KPA */
	/* { USB_DEVICE(0x0547, 0x6901) },  TT UCMOS09000KPB */
	/* { USB_DEVICE(0x0547, 0x6010) },  TT UCMOS10000KPA */
	/* { USB_DEVICE(0x0547, 0x6014) },  TT UCMOS14000KPA */
	/* { USB_DEVICE(0x0547, 0x6131) },  TT UCMOS01300KMA */
	/* { USB_DEVICE(0x0547, 0x6511) },  TT UCMOS05100KMA */
	/* { USB_DEVICE(0x0547, 0x8080) },  TT UHCCD00800KPA */
	/* { USB_DEVICE(0x0547, 0x8140) },  TT UHCCD01400KPA */
	/* { USB_DEVICE(0x0547, 0x8141) },  TT EXCCD01400KPA */
	/* { USB_DEVICE(0x0547, 0x8200) },  TT UHCCD02000KPA */
	/* { USB_DEVICE(0x0547, 0x8201) },  TT UHCCD02000KPB */
	/* { USB_DEVICE(0x0547, 0x8310) },  TT UHCCD03100KPA */
	/* { USB_DEVICE(0x0547, 0x8500) },  TT UHCCD05000KPA */
	/* { USB_DEVICE(0x0547, 0x8510) },  TT UHCCD05100KPA */
	/* { USB_DEVICE(0x0547, 0x8600) },  TT UHCCD06000KPA */
	/* { USB_DEVICE(0x0547, 0x8800) },  TT UHCCD08000KPA */
	/* { USB_DEVICE(0x0547, 0x8315) },  TT UHCCD03150KPA */
	/* { USB_DEVICE(0x0547, 0x7800) },  TT UHCCD00800KMA */
	/* { USB_DEVICE(0x0547, 0x7140) },  TT UHCCD01400KMA */
	/* { USB_DEVICE(0x0547, 0x7141) },  TT UHCCD01400KMB */
	/* { USB_DEVICE(0x0547, 0x7200) },  TT UHCCD02000KMA */
	/* { USB_DEVICE(0x0547, 0x7315) },  TT UHCCD03150KMA */
	{ }
};
MODULE_DEVICE_TABLE(usb, device_table);

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
};

static int __init sd_mod_init(void)
{
	int ret;

	ret = usb_register(&sd_driver);
	if (ret < 0)
		return ret;
	return 0;
}
static void __exit sd_mod_exit(void)
{
	usb_deregister(&sd_driver);
}

module_init(sd_mod_init);
module_exit(sd_mod_exit);