drivers/media/i2c/mt9v011.c - vendor/opensource/backports - Git at Google

 /*
  * mt9v011 -Micron 1/4-Inch VGA Digital Image Sensor
  *
  * Copyright (c) 2009 Mauro Carvalho Chehab
  * This code is placed under the terms of the GNU General Public License v2
  */

 #include <linux/i2c.h>
 #include <linux/slab.h>
 #include <linux/videodev2.h>
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <asm/div64.h>
 #include <media/v4l2-device.h>
 #include <media/v4l2-ctrls.h>
 #include <media/i2c/mt9v011.h>

 MODULE_DESCRIPTION("Micron mt9v011 sensor driver");
 MODULE_AUTHOR("Mauro Carvalho Chehab");
 MODULE_LICENSE("GPL");

 static int debug;
 module_param(debug, int, 0);
 MODULE_PARM_DESC(debug, "Debug level (0-2)");

 #define R00_MT9V011_CHIP_VERSION	0x00
 #define R01_MT9V011_ROWSTART		0x01
 #define R02_MT9V011_COLSTART		0x02
 #define R03_MT9V011_HEIGHT		0x03
 #define R04_MT9V011_WIDTH		0x04
 #define R05_MT9V011_HBLANK		0x05
 #define R06_MT9V011_VBLANK		0x06
 #define R07_MT9V011_OUT_CTRL		0x07
 #define R09_MT9V011_SHUTTER_WIDTH	0x09
 #define R0A_MT9V011_CLK_SPEED		0x0a
 #define R0B_MT9V011_RESTART		0x0b
 #define R0C_MT9V011_SHUTTER_DELAY	0x0c
 #define R0D_MT9V011_RESET		0x0d
 #define R1E_MT9V011_DIGITAL_ZOOM	0x1e
 #define R20_MT9V011_READ_MODE		0x20
 #define R2B_MT9V011_GREEN_1_GAIN	0x2b
 #define R2C_MT9V011_BLUE_GAIN		0x2c
 #define R2D_MT9V011_RED_GAIN		0x2d
 #define R2E_MT9V011_GREEN_2_GAIN	0x2e
 #define R35_MT9V011_GLOBAL_GAIN		0x35
 #define RF1_MT9V011_CHIP_ENABLE		0xf1

 #define MT9V011_VERSION			0x8232
 #define MT9V011_REV_B_VERSION		0x8243

 struct mt9v011 {
 	struct v4l2_subdev sd;
 	struct v4l2_ctrl_handler ctrls;
 	unsigned width, height;
 	unsigned xtal;
 	unsigned hflip:1;
 	unsigned vflip:1;

 	u16 global_gain, exposure;
 	s16 red_bal, blue_bal;
 };

 static inline struct mt9v011 *to_mt9v011(struct v4l2_subdev *sd)
 {
 	return container_of(sd, struct mt9v011, sd);
 }

 static int mt9v011_read(struct v4l2_subdev *sd, unsigned char addr)
 {
 	struct i2c_client *c = v4l2_get_subdevdata(sd);
 	__be16 buffer;
 	int rc, val;

 	rc = i2c_master_send(c, &addr, 1);
 	if (rc != 1)
 		v4l2_dbg(0, debug, sd,
 			 "i2c i/o error: rc == %d (should be 1)\n", rc);

 	msleep(10);

 	rc = i2c_master_recv(c, (char *)&buffer, 2);
 	if (rc != 2)
 		v4l2_dbg(0, debug, sd,
 			 "i2c i/o error: rc == %d (should be 2)\n", rc);

 	val = be16_to_cpu(buffer);

 	v4l2_dbg(2, debug, sd, "mt9v011: read 0x%02x = 0x%04x\n", addr, val);

 	return val;
 }

 static void mt9v011_write(struct v4l2_subdev *sd, unsigned char addr,
 				 u16 value)
 {
 	struct i2c_client *c = v4l2_get_subdevdata(sd);
 	unsigned char buffer[3];
 	int rc;

 	buffer[0] = addr;
 	buffer[1] = value >> 8;
 	buffer[2] = value & 0xff;

 	v4l2_dbg(2, debug, sd,
 		 "mt9v011: writing 0x%02x 0x%04x\n", buffer[0], value);
 	rc = i2c_master_send(c, buffer, 3);
 	if (rc != 3)
 		v4l2_dbg(0, debug, sd,
 			 "i2c i/o error: rc == %d (should be 3)\n", rc);
 }


 struct i2c_reg_value {
 	unsigned char reg;
 	u16           value;
 };

 /*
  * Values used at the original driver
  * Some values are marked as Reserved at the datasheet
  */
 static const struct i2c_reg_value mt9v011_init_default[] = {
 		{ R0D_MT9V011_RESET, 0x0001 },
 		{ R0D_MT9V011_RESET, 0x0000 },

 		{ R0C_MT9V011_SHUTTER_DELAY, 0x0000 },
 		{ R09_MT9V011_SHUTTER_WIDTH, 0x1fc },

 		{ R0A_MT9V011_CLK_SPEED, 0x0000 },
 		{ R1E_MT9V011_DIGITAL_ZOOM,  0x0000 },

 		{ R07_MT9V011_OUT_CTRL, 0x0002 },	/* chip enable */
 };


 static u16 calc_mt9v011_gain(s16 lineargain)
 {

 	u16 digitalgain = 0;
 	u16 analogmult = 0;
 	u16 analoginit = 0;

 	if (lineargain < 0)
 		lineargain = 0;

 	/* recommended minimum */
 	lineargain += 0x0020;

 	if (lineargain > 2047)
 		lineargain = 2047;

 	if (lineargain > 1023) {
 		digitalgain = 3;
 		analogmult = 3;
 		analoginit = lineargain / 16;
 	} else if (lineargain > 511) {
 		digitalgain = 1;
 		analogmult = 3;
 		analoginit = lineargain / 8;
 	} else if (lineargain > 255) {
 		analogmult = 3;
 		analoginit = lineargain / 4;
 	} else if (lineargain > 127) {
 		analogmult = 1;
 		analoginit = lineargain / 2;
 	} else
 		analoginit = lineargain;

 	return analoginit + (analogmult << 7) + (digitalgain << 9);

 }

 static void set_balance(struct v4l2_subdev *sd)
 {
 	struct mt9v011 *core = to_mt9v011(sd);
 	u16 green_gain, blue_gain, red_gain;
 	u16 exposure;
 	s16 bal;

 	exposure = core->exposure;

 	green_gain = calc_mt9v011_gain(core->global_gain);

 	bal = core->global_gain;
 	bal += (core->blue_bal * core->global_gain / (1 << 7));
 	blue_gain = calc_mt9v011_gain(bal);

 	bal = core->global_gain;
 	bal += (core->red_bal * core->global_gain / (1 << 7));
 	red_gain = calc_mt9v011_gain(bal);

 	mt9v011_write(sd, R2B_MT9V011_GREEN_1_GAIN, green_gain);
 	mt9v011_write(sd, R2E_MT9V011_GREEN_2_GAIN, green_gain);
 	mt9v011_write(sd, R2C_MT9V011_BLUE_GAIN, blue_gain);
 	mt9v011_write(sd, R2D_MT9V011_RED_GAIN, red_gain);
 	mt9v011_write(sd, R09_MT9V011_SHUTTER_WIDTH, exposure);
 }

 static void calc_fps(struct v4l2_subdev *sd, u32 *numerator, u32 *denominator)
 {
 	struct mt9v011 *core = to_mt9v011(sd);
 	unsigned height, width, hblank, vblank, speed;
 	unsigned row_time, t_time;
 	u64 frames_per_ms;
 	unsigned tmp;

 	height = mt9v011_read(sd, R03_MT9V011_HEIGHT);
 	width = mt9v011_read(sd, R04_MT9V011_WIDTH);
 	hblank = mt9v011_read(sd, R05_MT9V011_HBLANK);
 	vblank = mt9v011_read(sd, R06_MT9V011_VBLANK);
 	speed = mt9v011_read(sd, R0A_MT9V011_CLK_SPEED);

 	row_time = (width + 113 + hblank) * (speed + 2);
 	t_time = row_time * (height + vblank + 1);

 	frames_per_ms = core->xtal * 1000l;
 	do_div(frames_per_ms, t_time);
 	tmp = frames_per_ms;

 	v4l2_dbg(1, debug, sd, "Programmed to %u.%03u fps (%d pixel clcks)\n",
 		tmp / 1000, tmp % 1000, t_time);

 	if (numerator && denominator) {
 		*numerator = 1000;
 		*denominator = (u32)frames_per_ms;
 	}
 }

 static u16 calc_speed(struct v4l2_subdev *sd, u32 numerator, u32 denominator)
 {
 	struct mt9v011 *core = to_mt9v011(sd);
 	unsigned height, width, hblank, vblank;
 	unsigned row_time, line_time;
 	u64 t_time, speed;

 	/* Avoid bogus calculus */
 	if (!numerator || !denominator)
 		return 0;

 	height = mt9v011_read(sd, R03_MT9V011_HEIGHT);
 	width = mt9v011_read(sd, R04_MT9V011_WIDTH);
 	hblank = mt9v011_read(sd, R05_MT9V011_HBLANK);
 	vblank = mt9v011_read(sd, R06_MT9V011_VBLANK);

 	row_time = width + 113 + hblank;
 	line_time = height + vblank + 1;

 	t_time = core->xtal * ((u64)numerator);
 	/* round to the closest value */
 	t_time += denominator / 2;
 	do_div(t_time, denominator);

 	speed = t_time;
 	do_div(speed, row_time * line_time);

 	/* Avoid having a negative value for speed */
 	if (speed < 2)
 		speed = 0;
 	else
 		speed -= 2;

 	/* Avoid speed overflow */
 	if (speed > 15)
 		return 15;

 	return (u16)speed;
 }

 static void set_res(struct v4l2_subdev *sd)
 {
 	struct mt9v011 *core = to_mt9v011(sd);
 	unsigned vstart, hstart;

 	/*
 	 * The mt9v011 doesn't have scaling. So, in order to select the desired
 	 * resolution, we're cropping at the middle of the sensor.
 	 * hblank and vblank should be adjusted, in order to warrant that
 	 * we'll preserve the line timings for 30 fps, no matter what resolution
 	 * is selected.
 	 * NOTE: datasheet says that width (and height) should be filled with
 	 * width-1. However, this doesn't work, since one pixel per line will
 	 * be missing.
 	 */

 	hstart = 20 + (640 - core->width) / 2;
 	mt9v011_write(sd, R02_MT9V011_COLSTART, hstart);
 	mt9v011_write(sd, R04_MT9V011_WIDTH, core->width);
 	mt9v011_write(sd, R05_MT9V011_HBLANK, 771 - core->width);

 	vstart = 8 + (480 - core->height) / 2;
 	mt9v011_write(sd, R01_MT9V011_ROWSTART, vstart);
 	mt9v011_write(sd, R03_MT9V011_HEIGHT, core->height);
 	mt9v011_write(sd, R06_MT9V011_VBLANK, 508 - core->height);

 	calc_fps(sd, NULL, NULL);
 };

 static void set_read_mode(struct v4l2_subdev *sd)
 {
 	struct mt9v011 *core = to_mt9v011(sd);
 	unsigned mode = 0x1000;

 	if (core->hflip)
 		mode |= 0x4000;

 	if (core->vflip)
 		mode |= 0x8000;

 	mt9v011_write(sd, R20_MT9V011_READ_MODE, mode);
 }

 static int mt9v011_reset(struct v4l2_subdev *sd, u32 val)
 {
 	int i;

 	for (i = 0; i < ARRAY_SIZE(mt9v011_init_default); i++)
 		mt9v011_write(sd, mt9v011_init_default[i].reg,
 			       mt9v011_init_default[i].value);

 	set_balance(sd);
 	set_res(sd);
 	set_read_mode(sd);

 	return 0;
 }

 static int mt9v011_enum_mbus_code(struct v4l2_subdev *sd,
 		struct v4l2_subdev_pad_config *cfg,
 		struct v4l2_subdev_mbus_code_enum *code)
 {
 	if (code->pad || code->index > 0)
 		return -EINVAL;

 	code->code = MEDIA_BUS_FMT_SGRBG8_1X8;
 	return 0;
 }

 static int mt9v011_set_fmt(struct v4l2_subdev *sd,
 		struct v4l2_subdev_pad_config *cfg,
 		struct v4l2_subdev_format *format)
 {
 	struct v4l2_mbus_framefmt *fmt = &format->format;
 	struct mt9v011 *core = to_mt9v011(sd);

 	if (format->pad || fmt->code != MEDIA_BUS_FMT_SGRBG8_1X8)
 		return -EINVAL;

 	v4l_bound_align_image(&fmt->width, 48, 639, 1,
 			      &fmt->height, 32, 480, 1, 0);
 	fmt->field = V4L2_FIELD_NONE;
 	fmt->colorspace = V4L2_COLORSPACE_SRGB;

 	if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
 		core->width = fmt->width;
 		core->height = fmt->height;

 		set_res(sd);
 	} else {
 		cfg->try_fmt = *fmt;
 	}

 	return 0;
 }

 static int mt9v011_g_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms)
 {
 	struct v4l2_captureparm *cp = &parms->parm.capture;

 	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
 		return -EINVAL;

 	memset(cp, 0, sizeof(struct v4l2_captureparm));
 	cp->capability = V4L2_CAP_TIMEPERFRAME;
 	calc_fps(sd,
 		 &cp->timeperframe.numerator,
 		 &cp->timeperframe.denominator);

 	return 0;
 }

 static int mt9v011_s_parm(struct v4l2_subdev *sd, struct v4l2_streamparm *parms)
 {
 	struct v4l2_captureparm *cp = &parms->parm.capture;
 	struct v4l2_fract *tpf = &cp->timeperframe;
 	u16 speed;

 	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
 		return -EINVAL;
 	if (cp->extendedmode != 0)
 		return -EINVAL;

 	speed = calc_speed(sd, tpf->numerator, tpf->denominator);

 	mt9v011_write(sd, R0A_MT9V011_CLK_SPEED, speed);
 	v4l2_dbg(1, debug, sd, "Setting speed to %d\n", speed);

 	/* Recalculate and update fps info */
 	calc_fps(sd, &tpf->numerator, &tpf->denominator);

 	return 0;
 }

 #ifdef CPTCFG_VIDEO_ADV_DEBUG
 static int mt9v011_g_register(struct v4l2_subdev *sd,
 			      struct v4l2_dbg_register *reg)
 {
 	reg->val = mt9v011_read(sd, reg->reg & 0xff);
 	reg->size = 2;

 	return 0;
 }

 static int mt9v011_s_register(struct v4l2_subdev *sd,
 			      const struct v4l2_dbg_register *reg)
 {
 	mt9v011_write(sd, reg->reg & 0xff, reg->val & 0xffff);

 	return 0;
 }
 #endif

 static int mt9v011_s_ctrl(struct v4l2_ctrl *ctrl)
 {
 	struct mt9v011 *core =
 		container_of(ctrl->handler, struct mt9v011, ctrls);
 	struct v4l2_subdev *sd = &core->sd;

 	switch (ctrl->id) {
 	case V4L2_CID_GAIN:
 		core->global_gain = ctrl->val;
 		break;
 	case V4L2_CID_EXPOSURE:
 		core->exposure = ctrl->val;
 		break;
 	case V4L2_CID_RED_BALANCE:
 		core->red_bal = ctrl->val;
 		break;
 	case V4L2_CID_BLUE_BALANCE:
 		core->blue_bal = ctrl->val;
 		break;
 	case V4L2_CID_HFLIP:
 		core->hflip = ctrl->val;
 		set_read_mode(sd);
 		return 0;
 	case V4L2_CID_VFLIP:
 		core->vflip = ctrl->val;
 		set_read_mode(sd);
 		return 0;
 	default:
 		return -EINVAL;
 	}

 	set_balance(sd);
 	return 0;
 }

 static const struct v4l2_ctrl_ops mt9v011_ctrl_ops = {
 	.s_ctrl = mt9v011_s_ctrl,
 };

 static const struct v4l2_subdev_core_ops mt9v011_core_ops = {
 	.reset = mt9v011_reset,
 #ifdef CPTCFG_VIDEO_ADV_DEBUG
 	.g_register = mt9v011_g_register,
 	.s_register = mt9v011_s_register,
 #endif
 };

 static const struct v4l2_subdev_video_ops mt9v011_video_ops = {
 	.g_parm = mt9v011_g_parm,
 	.s_parm = mt9v011_s_parm,
 };

 static const struct v4l2_subdev_pad_ops mt9v011_pad_ops = {
 	.enum_mbus_code = mt9v011_enum_mbus_code,
 	.set_fmt = mt9v011_set_fmt,
 };

 static const struct v4l2_subdev_ops mt9v011_ops = {
 	.core  = &mt9v011_core_ops,
 	.video = &mt9v011_video_ops,
 	.pad   = &mt9v011_pad_ops,
 };


 /****************************************************************************
 			I2C Client & Driver
  ****************************************************************************/

 static int mt9v011_probe(struct i2c_client *c,
 			 const struct i2c_device_id *id)
 {
 	u16 version;
 	struct mt9v011 *core;
 	struct v4l2_subdev *sd;

 	/* Check if the adapter supports the needed features */
 	if (!i2c_check_functionality(c->adapter,
 	     I2C_FUNC_SMBUS_READ_BYTE | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
 		return -EIO;

 	core = devm_kzalloc(&c->dev, sizeof(struct mt9v011), GFP_KERNEL);
 	if (!core)
 		return -ENOMEM;

 	sd = &core->sd;
 	v4l2_i2c_subdev_init(sd, c, &mt9v011_ops);

 	/* Check if the sensor is really a MT9V011 */
 	version = mt9v011_read(sd, R00_MT9V011_CHIP_VERSION);
 	if ((version != MT9V011_VERSION) &&
 	    (version != MT9V011_REV_B_VERSION)) {
 		v4l2_info(sd, "*** unknown micron chip detected (0x%04x).\n",
 			  version);
 		return -EINVAL;
 	}

 	v4l2_ctrl_handler_init(&core->ctrls, 5);
 	v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
 			  V4L2_CID_GAIN, 0, (1 << 12) - 1 - 0x20, 1, 0x20);
 	v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
 			  V4L2_CID_EXPOSURE, 0, 2047, 1, 0x01fc);
 	v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
 			  V4L2_CID_RED_BALANCE, -(1 << 9), (1 << 9) - 1, 1, 0);
 	v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
 			  V4L2_CID_BLUE_BALANCE, -(1 << 9), (1 << 9) - 1, 1, 0);
 	v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
 			  V4L2_CID_HFLIP, 0, 1, 1, 0);
 	v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
 			  V4L2_CID_VFLIP, 0, 1, 1, 0);

 	if (core->ctrls.error) {
 		int ret = core->ctrls.error;

 		v4l2_err(sd, "control initialization error %d\n", ret);
 		v4l2_ctrl_handler_free(&core->ctrls);
 		return ret;
 	}
 	core->sd.ctrl_handler = &core->ctrls;

 	core->global_gain = 0x0024;
 	core->exposure = 0x01fc;
 	core->width  = 640;
 	core->height = 480;
 	core->xtal = 27000000;	/* Hz */

 	if (c->dev.platform_data) {
 		struct mt9v011_platform_data *pdata = c->dev.platform_data;

 		core->xtal = pdata->xtal;
 		v4l2_dbg(1, debug, sd, "xtal set to %d.%03d MHz\n",
 			core->xtal / 1000000, (core->xtal / 1000) % 1000);
 	}

 	v4l_info(c, "chip found @ 0x%02x (%s - chip version 0x%04x)\n",
 		 c->addr << 1, c->adapter->name, version);

 	return 0;
 }

 static int mt9v011_remove(struct i2c_client *c)
 {
 	struct v4l2_subdev *sd = i2c_get_clientdata(c);
 	struct mt9v011 *core = to_mt9v011(sd);

 	v4l2_dbg(1, debug, sd,
 		"mt9v011.c: removing mt9v011 adapter on address 0x%x\n",
 		c->addr << 1);

 	v4l2_device_unregister_subdev(sd);
 	v4l2_ctrl_handler_free(&core->ctrls);

 	return 0;
 }

 /* ----------------------------------------------------------------------- */

 static const struct i2c_device_id mt9v011_id[] = {
 	{ "mt9v011", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, mt9v011_id);

 static struct i2c_driver mt9v011_driver = {
 	.driver = {
 		.name	= "mt9v011",
 	},
 	.probe		= mt9v011_probe,
 	.remove		= mt9v011_remove,
 	.id_table	= mt9v011_id,
 };

 module_i2c_driver(mt9v011_driver);
	/*
	* mt9v011 -Micron 1/4-Inch VGA Digital Image Sensor
	*
	* Copyright (c) 2009 Mauro Carvalho Chehab
	* This code is placed under the terms of the GNU General Public License v2
	*/

	#include <linux/i2c.h>
	#include <linux/slab.h>
	#include <linux/videodev2.h>
	#include <linux/delay.h>
	#include <linux/module.h>
	#include <asm/div64.h>
	#include <media/v4l2-device.h>
	#include <media/v4l2-ctrls.h>
	#include <media/i2c/mt9v011.h>

	MODULE_DESCRIPTION("Micron mt9v011 sensor driver");
	MODULE_AUTHOR("Mauro Carvalho Chehab");
	MODULE_LICENSE("GPL");

	static int debug;
	module_param(debug, int, 0);
	MODULE_PARM_DESC(debug, "Debug level (0-2)");

	#define R00_MT9V011_CHIP_VERSION 0x00
	#define R01_MT9V011_ROWSTART 0x01
	#define R02_MT9V011_COLSTART 0x02
	#define R03_MT9V011_HEIGHT 0x03
	#define R04_MT9V011_WIDTH 0x04
	#define R05_MT9V011_HBLANK 0x05
	#define R06_MT9V011_VBLANK 0x06
	#define R07_MT9V011_OUT_CTRL 0x07
	#define R09_MT9V011_SHUTTER_WIDTH 0x09
	#define R0A_MT9V011_CLK_SPEED 0x0a
	#define R0B_MT9V011_RESTART 0x0b
	#define R0C_MT9V011_SHUTTER_DELAY 0x0c
	#define R0D_MT9V011_RESET 0x0d
	#define R1E_MT9V011_DIGITAL_ZOOM 0x1e
	#define R20_MT9V011_READ_MODE 0x20
	#define R2B_MT9V011_GREEN_1_GAIN 0x2b
	#define R2C_MT9V011_BLUE_GAIN 0x2c
	#define R2D_MT9V011_RED_GAIN 0x2d
	#define R2E_MT9V011_GREEN_2_GAIN 0x2e
	#define R35_MT9V011_GLOBAL_GAIN 0x35
	#define RF1_MT9V011_CHIP_ENABLE 0xf1

	#define MT9V011_VERSION 0x8232
	#define MT9V011_REV_B_VERSION 0x8243

	struct mt9v011 {
	struct v4l2_subdev sd;
	struct v4l2_ctrl_handler ctrls;
	unsigned width, height;
	unsigned xtal;
	unsigned hflip:1;
	unsigned vflip:1;

	u16 global_gain, exposure;
	s16 red_bal, blue_bal;
	};

	static inline struct mt9v011 to_mt9v011(struct v4l2_subdev sd)
	{
	return container_of(sd, struct mt9v011, sd);
	}

	static int mt9v011_read(struct v4l2_subdev *sd, unsigned char addr)
	{
	struct i2c_client *c = v4l2_get_subdevdata(sd);
	__be16 buffer;
	int rc, val;

	rc = i2c_master_send(c, &addr, 1);
	if (rc != 1)
	v4l2_dbg(0, debug, sd,
	"i2c i/o error: rc == %d (should be 1)\n", rc);

	msleep(10);

	rc = i2c_master_recv(c, (char *)&buffer, 2);
	if (rc != 2)
	v4l2_dbg(0, debug, sd,
	"i2c i/o error: rc == %d (should be 2)\n", rc);

	val = be16_to_cpu(buffer);

	v4l2_dbg(2, debug, sd, "mt9v011: read 0x%02x = 0x%04x\n", addr, val);

	return val;
	}

	static void mt9v011_write(struct v4l2_subdev *sd, unsigned char addr,
	u16 value)
	{
	struct i2c_client *c = v4l2_get_subdevdata(sd);
	unsigned char buffer[3];
	int rc;

	buffer[0] = addr;
	buffer[1] = value >> 8;
	buffer[2] = value & 0xff;

	v4l2_dbg(2, debug, sd,
	"mt9v011: writing 0x%02x 0x%04x\n", buffer[0], value);
	rc = i2c_master_send(c, buffer, 3);
	if (rc != 3)
	v4l2_dbg(0, debug, sd,
	"i2c i/o error: rc == %d (should be 3)\n", rc);
	}


	struct i2c_reg_value {
	unsigned char reg;
	u16 value;
	};

	/*
	* Values used at the original driver
	* Some values are marked as Reserved at the datasheet
	*/
	static const struct i2c_reg_value mt9v011_init_default[] = {
	{ R0D_MT9V011_RESET, 0x0001 },
	{ R0D_MT9V011_RESET, 0x0000 },

	{ R0C_MT9V011_SHUTTER_DELAY, 0x0000 },
	{ R09_MT9V011_SHUTTER_WIDTH, 0x1fc },

	{ R0A_MT9V011_CLK_SPEED, 0x0000 },
	{ R1E_MT9V011_DIGITAL_ZOOM, 0x0000 },

	{ R07_MT9V011_OUT_CTRL, 0x0002 }, /* chip enable */
	};


	static u16 calc_mt9v011_gain(s16 lineargain)
	{

	u16 digitalgain = 0;
	u16 analogmult = 0;
	u16 analoginit = 0;

	if (lineargain < 0)
	lineargain = 0;

	/* recommended minimum */
	lineargain += 0x0020;

	if (lineargain > 2047)
	lineargain = 2047;

	if (lineargain > 1023) {
	digitalgain = 3;
	analogmult = 3;
	analoginit = lineargain / 16;
	} else if (lineargain > 511) {
	digitalgain = 1;
	analogmult = 3;
	analoginit = lineargain / 8;
	} else if (lineargain > 255) {
	analogmult = 3;
	analoginit = lineargain / 4;
	} else if (lineargain > 127) {
	analogmult = 1;
	analoginit = lineargain / 2;
	} else
	analoginit = lineargain;

	return analoginit + (analogmult << 7) + (digitalgain << 9);

	}

	static void set_balance(struct v4l2_subdev *sd)
	{
	struct mt9v011 *core = to_mt9v011(sd);
	u16 green_gain, blue_gain, red_gain;
	u16 exposure;
	s16 bal;

	exposure = core->exposure;

	green_gain = calc_mt9v011_gain(core->global_gain);

	bal = core->global_gain;
	bal += (core->blue_bal * core->global_gain / (1 << 7));
	blue_gain = calc_mt9v011_gain(bal);

	bal = core->global_gain;
	bal += (core->red_bal * core->global_gain / (1 << 7));
	red_gain = calc_mt9v011_gain(bal);

	mt9v011_write(sd, R2B_MT9V011_GREEN_1_GAIN, green_gain);
	mt9v011_write(sd, R2E_MT9V011_GREEN_2_GAIN, green_gain);
	mt9v011_write(sd, R2C_MT9V011_BLUE_GAIN, blue_gain);
	mt9v011_write(sd, R2D_MT9V011_RED_GAIN, red_gain);
	mt9v011_write(sd, R09_MT9V011_SHUTTER_WIDTH, exposure);
	}

	static void calc_fps(struct v4l2_subdev sd, u32 numerator, u32 *denominator)
	{
	struct mt9v011 *core = to_mt9v011(sd);
	unsigned height, width, hblank, vblank, speed;
	unsigned row_time, t_time;
	u64 frames_per_ms;
	unsigned tmp;

	height = mt9v011_read(sd, R03_MT9V011_HEIGHT);
	width = mt9v011_read(sd, R04_MT9V011_WIDTH);
	hblank = mt9v011_read(sd, R05_MT9V011_HBLANK);
	vblank = mt9v011_read(sd, R06_MT9V011_VBLANK);
	speed = mt9v011_read(sd, R0A_MT9V011_CLK_SPEED);

	row_time = (width + 113 + hblank) * (speed + 2);
	t_time = row_time * (height + vblank + 1);

	frames_per_ms = core->xtal * 1000l;
	do_div(frames_per_ms, t_time);
	tmp = frames_per_ms;

	v4l2_dbg(1, debug, sd, "Programmed to %u.%03u fps (%d pixel clcks)\n",
	tmp / 1000, tmp % 1000, t_time);

	if (numerator && denominator) {
	*numerator = 1000;
	*denominator = (u32)frames_per_ms;
	}
	}

	static u16 calc_speed(struct v4l2_subdev *sd, u32 numerator, u32 denominator)
	{
	struct mt9v011 *core = to_mt9v011(sd);
	unsigned height, width, hblank, vblank;
	unsigned row_time, line_time;
	u64 t_time, speed;

	/* Avoid bogus calculus */
	if (!numerator \|\| !denominator)
	return 0;

	height = mt9v011_read(sd, R03_MT9V011_HEIGHT);
	width = mt9v011_read(sd, R04_MT9V011_WIDTH);
	hblank = mt9v011_read(sd, R05_MT9V011_HBLANK);
	vblank = mt9v011_read(sd, R06_MT9V011_VBLANK);

	row_time = width + 113 + hblank;
	line_time = height + vblank + 1;

	t_time = core->xtal * ((u64)numerator);
	/* round to the closest value */
	t_time += denominator / 2;
	do_div(t_time, denominator);

	speed = t_time;
	do_div(speed, row_time * line_time);

	/* Avoid having a negative value for speed */
	if (speed < 2)
	speed = 0;
	else
	speed -= 2;

	/* Avoid speed overflow */
	if (speed > 15)
	return 15;

	return (u16)speed;
	}

	static void set_res(struct v4l2_subdev *sd)
	{
	struct mt9v011 *core = to_mt9v011(sd);
	unsigned vstart, hstart;

	/*
	* The mt9v011 doesn't have scaling. So, in order to select the desired
	* resolution, we're cropping at the middle of the sensor.
	* hblank and vblank should be adjusted, in order to warrant that
	* we'll preserve the line timings for 30 fps, no matter what resolution
	* is selected.
	* NOTE: datasheet says that width (and height) should be filled with
	* width-1. However, this doesn't work, since one pixel per line will
	* be missing.
	*/

	hstart = 20 + (640 - core->width) / 2;
	mt9v011_write(sd, R02_MT9V011_COLSTART, hstart);
	mt9v011_write(sd, R04_MT9V011_WIDTH, core->width);
	mt9v011_write(sd, R05_MT9V011_HBLANK, 771 - core->width);

	vstart = 8 + (480 - core->height) / 2;
	mt9v011_write(sd, R01_MT9V011_ROWSTART, vstart);
	mt9v011_write(sd, R03_MT9V011_HEIGHT, core->height);
	mt9v011_write(sd, R06_MT9V011_VBLANK, 508 - core->height);

	calc_fps(sd, NULL, NULL);
	};

	static void set_read_mode(struct v4l2_subdev *sd)
	{
	struct mt9v011 *core = to_mt9v011(sd);
	unsigned mode = 0x1000;

	if (core->hflip)
	mode \|= 0x4000;

	if (core->vflip)
	mode \|= 0x8000;

	mt9v011_write(sd, R20_MT9V011_READ_MODE, mode);
	}

	static int mt9v011_reset(struct v4l2_subdev *sd, u32 val)
	{
	int i;

	for (i = 0; i < ARRAY_SIZE(mt9v011_init_default); i++)
	mt9v011_write(sd, mt9v011_init_default[i].reg,
	mt9v011_init_default[i].value);

	set_balance(sd);
	set_res(sd);
	set_read_mode(sd);

	return 0;
	}

	static int mt9v011_enum_mbus_code(struct v4l2_subdev *sd,
	struct v4l2_subdev_pad_config *cfg,
	struct v4l2_subdev_mbus_code_enum *code)
	{
	if (code->pad \|\| code->index > 0)
	return -EINVAL;

	code->code = MEDIA_BUS_FMT_SGRBG8_1X8;
	return 0;
	}

	static int mt9v011_set_fmt(struct v4l2_subdev *sd,
	struct v4l2_subdev_pad_config *cfg,
	struct v4l2_subdev_format *format)
	{
	struct v4l2_mbus_framefmt *fmt = &format->format;
	struct mt9v011 *core = to_mt9v011(sd);

	if (format->pad \|\| fmt->code != MEDIA_BUS_FMT_SGRBG8_1X8)
	return -EINVAL;

	v4l_bound_align_image(&fmt->width, 48, 639, 1,
	&fmt->height, 32, 480, 1, 0);
	fmt->field = V4L2_FIELD_NONE;
	fmt->colorspace = V4L2_COLORSPACE_SRGB;

	if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
	core->width = fmt->width;
	core->height = fmt->height;

	set_res(sd);
	} else {
	cfg->try_fmt = *fmt;
	}

	return 0;
	}

	static int mt9v011_g_parm(struct v4l2_subdev sd, struct v4l2_streamparm parms)
	{
	struct v4l2_captureparm *cp = &parms->parm.capture;

	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
	return -EINVAL;

	memset(cp, 0, sizeof(struct v4l2_captureparm));
	cp->capability = V4L2_CAP_TIMEPERFRAME;
	calc_fps(sd,
	&cp->timeperframe.numerator,
	&cp->timeperframe.denominator);

	return 0;
	}

	static int mt9v011_s_parm(struct v4l2_subdev sd, struct v4l2_streamparm parms)
	{
	struct v4l2_captureparm *cp = &parms->parm.capture;
	struct v4l2_fract *tpf = &cp->timeperframe;
	u16 speed;

	if (parms->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
	return -EINVAL;
	if (cp->extendedmode != 0)
	return -EINVAL;

	speed = calc_speed(sd, tpf->numerator, tpf->denominator);

	mt9v011_write(sd, R0A_MT9V011_CLK_SPEED, speed);
	v4l2_dbg(1, debug, sd, "Setting speed to %d\n", speed);

	/* Recalculate and update fps info */
	calc_fps(sd, &tpf->numerator, &tpf->denominator);

	return 0;
	}

	#ifdef CPTCFG_VIDEO_ADV_DEBUG
	static int mt9v011_g_register(struct v4l2_subdev *sd,
	struct v4l2_dbg_register *reg)
	{
	reg->val = mt9v011_read(sd, reg->reg & 0xff);
	reg->size = 2;

	return 0;
	}

	static int mt9v011_s_register(struct v4l2_subdev *sd,
	const struct v4l2_dbg_register *reg)
	{
	mt9v011_write(sd, reg->reg & 0xff, reg->val & 0xffff);

	return 0;
	}
	#endif

	static int mt9v011_s_ctrl(struct v4l2_ctrl *ctrl)
	{
	struct mt9v011 *core =
	container_of(ctrl->handler, struct mt9v011, ctrls);
	struct v4l2_subdev *sd = &core->sd;

	switch (ctrl->id) {
	case V4L2_CID_GAIN:
	core->global_gain = ctrl->val;
	break;
	case V4L2_CID_EXPOSURE:
	core->exposure = ctrl->val;
	break;
	case V4L2_CID_RED_BALANCE:
	core->red_bal = ctrl->val;
	break;
	case V4L2_CID_BLUE_BALANCE:
	core->blue_bal = ctrl->val;
	break;
	case V4L2_CID_HFLIP:
	core->hflip = ctrl->val;
	set_read_mode(sd);
	return 0;
	case V4L2_CID_VFLIP:
	core->vflip = ctrl->val;
	set_read_mode(sd);
	return 0;
	default:
	return -EINVAL;
	}

	set_balance(sd);
	return 0;
	}

	static const struct v4l2_ctrl_ops mt9v011_ctrl_ops = {
	.s_ctrl = mt9v011_s_ctrl,
	};

	static const struct v4l2_subdev_core_ops mt9v011_core_ops = {
	.reset = mt9v011_reset,
	#ifdef CPTCFG_VIDEO_ADV_DEBUG
	.g_register = mt9v011_g_register,
	.s_register = mt9v011_s_register,
	#endif
	};

	static const struct v4l2_subdev_video_ops mt9v011_video_ops = {
	.g_parm = mt9v011_g_parm,
	.s_parm = mt9v011_s_parm,
	};

	static const struct v4l2_subdev_pad_ops mt9v011_pad_ops = {
	.enum_mbus_code = mt9v011_enum_mbus_code,
	.set_fmt = mt9v011_set_fmt,
	};

	static const struct v4l2_subdev_ops mt9v011_ops = {
	.core = &mt9v011_core_ops,
	.video = &mt9v011_video_ops,
	.pad = &mt9v011_pad_ops,
	};


	/****************************************************************************
	I2C Client & Driver
	****************************************************************************/

	static int mt9v011_probe(struct i2c_client *c,
	const struct i2c_device_id *id)
	{
	u16 version;
	struct mt9v011 *core;
	struct v4l2_subdev *sd;

	/* Check if the adapter supports the needed features */
	if (!i2c_check_functionality(c->adapter,
	I2C_FUNC_SMBUS_READ_BYTE \| I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
	return -EIO;

	core = devm_kzalloc(&c->dev, sizeof(struct mt9v011), GFP_KERNEL);
	if (!core)
	return -ENOMEM;

	sd = &core->sd;
	v4l2_i2c_subdev_init(sd, c, &mt9v011_ops);

	/* Check if the sensor is really a MT9V011 */
	version = mt9v011_read(sd, R00_MT9V011_CHIP_VERSION);
	if ((version != MT9V011_VERSION) &&
	(version != MT9V011_REV_B_VERSION)) {
	v4l2_info(sd, "*** unknown micron chip detected (0x%04x).\n",
	version);
	return -EINVAL;
	}

	v4l2_ctrl_handler_init(&core->ctrls, 5);
	v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
	V4L2_CID_GAIN, 0, (1 << 12) - 1 - 0x20, 1, 0x20);
	v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
	V4L2_CID_EXPOSURE, 0, 2047, 1, 0x01fc);
	v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
	V4L2_CID_RED_BALANCE, -(1 << 9), (1 << 9) - 1, 1, 0);
	v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
	V4L2_CID_BLUE_BALANCE, -(1 << 9), (1 << 9) - 1, 1, 0);
	v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
	V4L2_CID_HFLIP, 0, 1, 1, 0);
	v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
	V4L2_CID_VFLIP, 0, 1, 1, 0);

	if (core->ctrls.error) {
	int ret = core->ctrls.error;

	v4l2_err(sd, "control initialization error %d\n", ret);
	v4l2_ctrl_handler_free(&core->ctrls);
	return ret;
	}
	core->sd.ctrl_handler = &core->ctrls;

	core->global_gain = 0x0024;
	core->exposure = 0x01fc;
	core->width = 640;
	core->height = 480;
	core->xtal = 27000000; /* Hz */

	if (c->dev.platform_data) {
	struct mt9v011_platform_data *pdata = c->dev.platform_data;

	core->xtal = pdata->xtal;
	v4l2_dbg(1, debug, sd, "xtal set to %d.%03d MHz\n",
	core->xtal / 1000000, (core->xtal / 1000) % 1000);
	}

	v4l_info(c, "chip found @ 0x%02x (%s - chip version 0x%04x)\n",
	c->addr << 1, c->adapter->name, version);

	return 0;
	}

	static int mt9v011_remove(struct i2c_client *c)
	{
	struct v4l2_subdev *sd = i2c_get_clientdata(c);
	struct mt9v011 *core = to_mt9v011(sd);

	v4l2_dbg(1, debug, sd,
	"mt9v011.c: removing mt9v011 adapter on address 0x%x\n",
	c->addr << 1);

	v4l2_device_unregister_subdev(sd);
	v4l2_ctrl_handler_free(&core->ctrls);

	return 0;
	}

	/* ----------------------------------------------------------------------- */

	static const struct i2c_device_id mt9v011_id[] = {
	{ "mt9v011", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, mt9v011_id);

	static struct i2c_driver mt9v011_driver = {
	.driver = {
	.name = "mt9v011",
	},
	.probe = mt9v011_probe,
	.remove = mt9v011_remove,
	.id_table = mt9v011_id,
	};

	module_i2c_driver(mt9v011_driver);