[media] mt9p031: Aptina (Micron) MT9P031 5MP sensor driver

The MT9P031 is a parallel 12-bit 5MP sensor from Aptina (formerly
Micron) controlled through I2C.

The driver creates a V4L2 subdevice. It currently supports skipping,
cropping, automatic binning, and gain, exposure, h/v flip and test
pattern controls.
Signed-off-by: Javier Martin <javier.martin@vista-silicon.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/Kconfig

@@ -467,6 +467,13 @@ config VIDEO_OV7670
 	  OV7670 VGA camera.  It currently only works with the M88ALP01
 	  controller.
 
+config VIDEO_MT9P031
+	tristate "Aptina MT9P031 support"
+	depends on I2C && VIDEO_V4L2
+	---help---
+	  This is a Video4Linux2 sensor-level driver for the Aptina
+	  (Micron) mt9p031 5 Mpixel camera.
+
 config VIDEO_MT9V011
 	tristate "Micron mt9v011 sensor support"
 	depends on I2C && VIDEO_V4L2

drivers/media/video/Makefile

@@ -65,6 +65,7 @@ obj-$(CONFIG_VIDEO_UPD64083) += upd64083.o
 obj-$(CONFIG_VIDEO_OV7670) 	+= ov7670.o
 obj-$(CONFIG_VIDEO_TCM825X) += tcm825x.o
 obj-$(CONFIG_VIDEO_TVEEPROM) += tveeprom.o
+obj-$(CONFIG_VIDEO_MT9P031) += mt9p031.o
 obj-$(CONFIG_VIDEO_MT9V011) += mt9v011.o
 obj-$(CONFIG_VIDEO_MT9V032) += mt9v032.o
 obj-$(CONFIG_VIDEO_SR030PC30)	+= sr030pc30.o

drivers/media/video/mt9p031.c

+/*
+ * Driver for MT9P031 CMOS Image Sensor from Aptina
+ *
+ * Copyright (C) 2011, Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ * Copyright (C) 2011, Javier Martin <javier.martin@vista-silicon.com>
+ * Copyright (C) 2011, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
+ *
+ * Based on the MT9V032 driver and Bastian Hecht's code.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/log2.h>
+#include <linux/pm.h>
+#include <linux/slab.h>
+#include <media/v4l2-subdev.h>
+#include <linux/videodev2.h>
+
+#include <media/mt9p031.h>
+#include <media/v4l2-chip-ident.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-subdev.h>
+
+#define MT9P031_PIXEL_ARRAY_WIDTH			2752
+#define MT9P031_PIXEL_ARRAY_HEIGHT			2004
+
+#define MT9P031_CHIP_VERSION				0x00
+#define		MT9P031_CHIP_VERSION_VALUE		0x1801
+#define MT9P031_ROW_START				0x01
+#define		MT9P031_ROW_START_MIN			0
+#define		MT9P031_ROW_START_MAX			2004
+#define		MT9P031_ROW_START_DEF			54
+#define MT9P031_COLUMN_START				0x02
+#define		MT9P031_COLUMN_START_MIN		0
+#define		MT9P031_COLUMN_START_MAX		2750
+#define		MT9P031_COLUMN_START_DEF		16
+#define MT9P031_WINDOW_HEIGHT				0x03
+#define		MT9P031_WINDOW_HEIGHT_MIN		2
+#define		MT9P031_WINDOW_HEIGHT_MAX		2006
+#define		MT9P031_WINDOW_HEIGHT_DEF		1944
+#define MT9P031_WINDOW_WIDTH				0x04
+#define		MT9P031_WINDOW_WIDTH_MIN		2
+#define		MT9P031_WINDOW_WIDTH_MAX		2752
+#define		MT9P031_WINDOW_WIDTH_DEF		2592
+#define MT9P031_HORIZONTAL_BLANK			0x05
+#define		MT9P031_HORIZONTAL_BLANK_MIN		0
+#define		MT9P031_HORIZONTAL_BLANK_MAX		4095
+#define MT9P031_VERTICAL_BLANK				0x06
+#define		MT9P031_VERTICAL_BLANK_MIN		0
+#define		MT9P031_VERTICAL_BLANK_MAX		4095
+#define		MT9P031_VERTICAL_BLANK_DEF		25
+#define MT9P031_OUTPUT_CONTROL				0x07
+#define		MT9P031_OUTPUT_CONTROL_CEN		2
+#define		MT9P031_OUTPUT_CONTROL_SYN		1
+#define		MT9P031_OUTPUT_CONTROL_DEF		0x1f82
+#define MT9P031_SHUTTER_WIDTH_UPPER			0x08
+#define MT9P031_SHUTTER_WIDTH_LOWER			0x09
+#define		MT9P031_SHUTTER_WIDTH_MIN		1
+#define		MT9P031_SHUTTER_WIDTH_MAX		1048575
+#define		MT9P031_SHUTTER_WIDTH_DEF		1943
+#define	MT9P031_PLL_CONTROL				0x10
+#define		MT9P031_PLL_CONTROL_PWROFF		0x0050
+#define		MT9P031_PLL_CONTROL_PWRON		0x0051
+#define		MT9P031_PLL_CONTROL_USEPLL		0x0052
+#define	MT9P031_PLL_CONFIG_1				0x11
+#define	MT9P031_PLL_CONFIG_2				0x12
+#define MT9P031_PIXEL_CLOCK_CONTROL			0x0a
+#define MT9P031_FRAME_RESTART				0x0b
+#define MT9P031_SHUTTER_DELAY				0x0c
+#define MT9P031_RST					0x0d
+#define		MT9P031_RST_ENABLE			1
+#define		MT9P031_RST_DISABLE			0
+#define MT9P031_READ_MODE_1				0x1e
+#define MT9P031_READ_MODE_2				0x20
+#define		MT9P031_READ_MODE_2_ROW_MIR		(1 << 15)
+#define		MT9P031_READ_MODE_2_COL_MIR		(1 << 14)
+#define		MT9P031_READ_MODE_2_ROW_BLC		(1 << 6)
+#define MT9P031_ROW_ADDRESS_MODE			0x22
+#define MT9P031_COLUMN_ADDRESS_MODE			0x23
+#define MT9P031_GLOBAL_GAIN				0x35
+#define		MT9P031_GLOBAL_GAIN_MIN			8
+#define		MT9P031_GLOBAL_GAIN_MAX			1024
+#define		MT9P031_GLOBAL_GAIN_DEF			8
+#define		MT9P031_GLOBAL_GAIN_MULT		(1 << 6)
+#define MT9P031_ROW_BLACK_DEF_OFFSET			0x4b
+#define MT9P031_TEST_PATTERN				0xa0
+#define		MT9P031_TEST_PATTERN_SHIFT		3
+#define		MT9P031_TEST_PATTERN_ENABLE		(1 << 0)
+#define		MT9P031_TEST_PATTERN_DISABLE		(0 << 0)
+#define MT9P031_TEST_PATTERN_GREEN			0xa1
+#define MT9P031_TEST_PATTERN_RED			0xa2
+#define MT9P031_TEST_PATTERN_BLUE			0xa3
+
+struct mt9p031_pll_divs {
+	u32 ext_freq;
+	u32 target_freq;
+	u8 m;
+	u8 n;
+	u8 p1;
+};
+
+struct mt9p031 {
+	struct v4l2_subdev subdev;
+	struct media_pad pad;
+	struct v4l2_rect crop;  /* Sensor window */
+	struct v4l2_mbus_framefmt format;
+	struct v4l2_ctrl_handler ctrls;
+	struct mt9p031_platform_data *pdata;
+	struct mutex power_lock; /* lock to protect power_count */
+	int power_count;
+	u16 xskip;
+	u16 yskip;
+
+	const struct mt9p031_pll_divs *pll;
+
+	/* Registers cache */
+	u16 output_control;
+	u16 mode2;
+};
+
+static struct mt9p031 *to_mt9p031(struct v4l2_subdev *sd)
+{
+	return container_of(sd, struct mt9p031, subdev);
+}
+
+static int mt9p031_read(struct i2c_client *client, u8 reg)
+{
+	s32 data = i2c_smbus_read_word_data(client, reg);
+	return data < 0 ? data : be16_to_cpu(data);
+}
+
+static int mt9p031_write(struct i2c_client *client, u8 reg, u16 data)
+{
+	return i2c_smbus_write_word_data(client, reg, cpu_to_be16(data));
+}
+
+static int mt9p031_set_output_control(struct mt9p031 *mt9p031, u16 clear,
+				      u16 set)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
+	u16 value = (mt9p031->output_control & ~clear) | set;
+	int ret;
+
+	ret = mt9p031_write(client, MT9P031_OUTPUT_CONTROL, value);
+	if (ret < 0)
+		return ret;
+
+	mt9p031->output_control = value;
+	return 0;
+}
+
+static int mt9p031_set_mode2(struct mt9p031 *mt9p031, u16 clear, u16 set)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
+	u16 value = (mt9p031->mode2 & ~clear) | set;
+	int ret;
+
+	ret = mt9p031_write(client, MT9P031_READ_MODE_2, value);
+	if (ret < 0)
+		return ret;
+
+	mt9p031->mode2 = value;
+	return 0;
+}
+
+static int mt9p031_reset(struct mt9p031 *mt9p031)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
+	int ret;
+
+	/* Disable chip output, synchronous option update */
+	ret = mt9p031_write(client, MT9P031_RST, MT9P031_RST_ENABLE);
+	if (ret < 0)
+		return ret;
+	ret = mt9p031_write(client, MT9P031_RST, MT9P031_RST_DISABLE);
+	if (ret < 0)
+		return ret;
+
+	return mt9p031_set_output_control(mt9p031, MT9P031_OUTPUT_CONTROL_CEN,
+					  0);
+}
+
+/*
+ * This static table uses ext_freq and vdd_io values to select suitable
+ * PLL dividers m, n and p1 which have been calculated as specifiec in p36
+ * of Aptina's mt9p031 datasheet. New values should be added here.
+ */
+static const struct mt9p031_pll_divs mt9p031_divs[] = {
+	/* ext_freq	target_freq	m	n	p1 */
+	{21000000,	48000000,	26,	2,	6}
+};
+
+static int mt9p031_pll_get_divs(struct mt9p031 *mt9p031)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(mt9p031_divs); i++) {
+		if (mt9p031_divs[i].ext_freq == mt9p031->pdata->ext_freq &&
+		  mt9p031_divs[i].target_freq == mt9p031->pdata->target_freq) {
+			mt9p031->pll = &mt9p031_divs[i];
+			return 0;
+		}
+	}
+
+	dev_err(&client->dev, "Couldn't find PLL dividers for ext_freq = %d, "
+		"target_freq = %d\n", mt9p031->pdata->ext_freq,
+		mt9p031->pdata->target_freq);
+	return -EINVAL;
+}
+
+static int mt9p031_pll_enable(struct mt9p031 *mt9p031)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
+	int ret;
+
+	ret = mt9p031_write(client, MT9P031_PLL_CONTROL,
+			    MT9P031_PLL_CONTROL_PWRON);
+	if (ret < 0)
+		return ret;
+
+	ret = mt9p031_write(client, MT9P031_PLL_CONFIG_1,
+			    (mt9p031->pll->m << 8) | (mt9p031->pll->n - 1));
+	if (ret < 0)
+		return ret;
+
+	ret = mt9p031_write(client, MT9P031_PLL_CONFIG_2, mt9p031->pll->p1 - 1);
+	if (ret < 0)
+		return ret;
+
+	usleep_range(1000, 2000);
+	ret = mt9p031_write(client, MT9P031_PLL_CONTROL,
+			    MT9P031_PLL_CONTROL_PWRON |
+			    MT9P031_PLL_CONTROL_USEPLL);
+	return ret;
+}
+
+static inline int mt9p031_pll_disable(struct mt9p031 *mt9p031)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
+
+	return mt9p031_write(client, MT9P031_PLL_CONTROL,
+			     MT9P031_PLL_CONTROL_PWROFF);
+}
+
+static int mt9p031_power_on(struct mt9p031 *mt9p031)
+{
+	/* Ensure RESET_BAR is low */
+	if (mt9p031->pdata->reset) {
+		mt9p031->pdata->reset(&mt9p031->subdev, 1);
+		usleep_range(1000, 2000);
+	}
+
+	/* Emable clock */
+	if (mt9p031->pdata->set_xclk)
+		mt9p031->pdata->set_xclk(&mt9p031->subdev,
+					 mt9p031->pdata->ext_freq);
+
+	/* Now RESET_BAR must be high */
+	if (mt9p031->pdata->reset) {
+		mt9p031->pdata->reset(&mt9p031->subdev, 0);
+		usleep_range(1000, 2000);
+	}
+
+	return 0;
+}
+
+static void mt9p031_power_off(struct mt9p031 *mt9p031)
+{
+	if (mt9p031->pdata->reset) {
+		mt9p031->pdata->reset(&mt9p031->subdev, 1);
+		usleep_range(1000, 2000);
+	}
+
+	if (mt9p031->pdata->set_xclk)
+		mt9p031->pdata->set_xclk(&mt9p031->subdev, 0);
+}
+
+static int __mt9p031_set_power(struct mt9p031 *mt9p031, bool on)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
+	int ret;
+
+	if (!on) {
+		mt9p031_power_off(mt9p031);
+		return 0;
+	}
+
+	ret = mt9p031_power_on(mt9p031);
+	if (ret < 0)
+		return ret;
+
+	ret = mt9p031_reset(mt9p031);
+	if (ret < 0) {
+		dev_err(&client->dev, "Failed to reset the camera\n");
+		return ret;
+	}
+
+	return v4l2_ctrl_handler_setup(&mt9p031->ctrls);
+}
+
+/* -----------------------------------------------------------------------------
+ * V4L2 subdev video operations
+ */
+
+static int mt9p031_set_params(struct mt9p031 *mt9p031)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
+	struct v4l2_mbus_framefmt *format = &mt9p031->format;
+	const struct v4l2_rect *crop = &mt9p031->crop;
+	unsigned int hblank;
+	unsigned int vblank;
+	unsigned int xskip;
+	unsigned int yskip;
+	unsigned int xbin;
+	unsigned int ybin;
+	int ret;
+
+	/* Windows position and size.
+	 *
+	 * TODO: Make sure the start coordinates and window size match the
+	 * skipping, binning and mirroring (see description of registers 2 and 4
+	 * in table 13, and Binning section on page 41).
+	 */
+	ret = mt9p031_write(client, MT9P031_COLUMN_START, crop->left);
+	if (ret < 0)
+		return ret;
+	ret = mt9p031_write(client, MT9P031_ROW_START, crop->top);
+	if (ret < 0)
+		return ret;
+	ret = mt9p031_write(client, MT9P031_WINDOW_WIDTH, crop->width - 1);
+	if (ret < 0)
+		return ret;
+	ret = mt9p031_write(client, MT9P031_WINDOW_HEIGHT, crop->height - 1);
+	if (ret < 0)
+		return ret;
+
+	/* Row and column binning and skipping. Use the maximum binning value
+	 * compatible with the skipping settings.
+	 */
+	xskip = DIV_ROUND_CLOSEST(crop->width, format->width);
+	yskip = DIV_ROUND_CLOSEST(crop->height, format->height);
+	xbin = 1 << (ffs(xskip) - 1);
+	ybin = 1 << (ffs(yskip) - 1);
+
+	ret = mt9p031_write(client, MT9P031_COLUMN_ADDRESS_MODE,
+			    ((xbin - 1) << 4) | (xskip - 1));
+	if (ret < 0)
+		return ret;
+	ret = mt9p031_write(client, MT9P031_ROW_ADDRESS_MODE,
+			    ((ybin - 1) << 4) | (yskip - 1));
+	if (ret < 0)
+		return ret;
+
+	/* Blanking - use minimum value for horizontal blanking and default
+	 * value for vertical blanking.
+	 */
+	hblank = 346 * ybin + 64 + (80 >> max_t(unsigned int, xbin, 3));
+	vblank = MT9P031_VERTICAL_BLANK_DEF;
+
+	ret = mt9p031_write(client, MT9P031_HORIZONTAL_BLANK, hblank);
+	if (ret < 0)
+		return ret;
+	ret = mt9p031_write(client, MT9P031_VERTICAL_BLANK, vblank);
+	if (ret < 0)
+		return ret;
+
+	return ret;
+}
+
+static int mt9p031_s_stream(struct v4l2_subdev *subdev, int enable)
+{
+	struct mt9p031 *mt9p031 = to_mt9p031(subdev);
+	int ret;
+
+	if (!enable) {
+		/* Stop sensor readout */
+		ret = mt9p031_set_output_control(mt9p031,
+						 MT9P031_OUTPUT_CONTROL_CEN, 0);
+		if (ret < 0)
+			return ret;
+
+		return mt9p031_pll_disable(mt9p031);
+	}
+
+	ret = mt9p031_set_params(mt9p031);
+	if (ret < 0)
+		return ret;
+
+	/* Switch to master "normal" mode */
+	ret = mt9p031_set_output_control(mt9p031, 0,
+					 MT9P031_OUTPUT_CONTROL_CEN);
+	if (ret < 0)
+		return ret;
+
+	return mt9p031_pll_enable(mt9p031);
+}
+
+static int mt9p031_enum_mbus_code(struct v4l2_subdev *subdev,
+				  struct v4l2_subdev_fh *fh,
+				  struct v4l2_subdev_mbus_code_enum *code)
+{
+	struct mt9p031 *mt9p031 = to_mt9p031(subdev);
+
+	if (code->pad || code->index)
+		return -EINVAL;
+
+	code->code = mt9p031->format.code;
+	return 0;
+}
+
+static int mt9p031_enum_frame_size(struct v4l2_subdev *subdev,
+				   struct v4l2_subdev_fh *fh,
+				   struct v4l2_subdev_frame_size_enum *fse)
+{
+	struct mt9p031 *mt9p031 = to_mt9p031(subdev);
+
+	if (fse->index >= 8 || fse->code != mt9p031->format.code)
+		return -EINVAL;
+
+	fse->min_width = MT9P031_WINDOW_WIDTH_DEF
+		       / min_t(unsigned int, 7, fse->index + 1);
+	fse->max_width = fse->min_width;
+	fse->min_height = MT9P031_WINDOW_HEIGHT_DEF / (fse->index + 1);
+	fse->max_height = fse->min_height;
+
+	return 0;
+}
+
+static struct v4l2_mbus_framefmt *
+__mt9p031_get_pad_format(struct mt9p031 *mt9p031, struct v4l2_subdev_fh *fh,
+			 unsigned int pad, u32 which)
+{
+	switch (which) {
+	case V4L2_SUBDEV_FORMAT_TRY:
+		return v4l2_subdev_get_try_format(fh, pad);
+	case V4L2_SUBDEV_FORMAT_ACTIVE:
+		return &mt9p031->format;
+	default:
+		return NULL;
+	}
+}
+
+static struct v4l2_rect *
+__mt9p031_get_pad_crop(struct mt9p031 *mt9p031, struct v4l2_subdev_fh *fh,
+		     unsigned int pad, u32 which)
+{
+	switch (which) {
+	case V4L2_SUBDEV_FORMAT_TRY:
+		return v4l2_subdev_get_try_crop(fh, pad);
+	case V4L2_SUBDEV_FORMAT_ACTIVE:
+		return &mt9p031->crop;
+	default:
+		return NULL;
+	}
+}
+
+static int mt9p031_get_format(struct v4l2_subdev *subdev,
+			      struct v4l2_subdev_fh *fh,
+			      struct v4l2_subdev_format *fmt)
+{
+	struct mt9p031 *mt9p031 = to_mt9p031(subdev);
+
+	fmt->format = *__mt9p031_get_pad_format(mt9p031, fh, fmt->pad,
+						fmt->which);
+	return 0;
+}
+
+static int mt9p031_set_format(struct v4l2_subdev *subdev,
+			      struct v4l2_subdev_fh *fh,
+			      struct v4l2_subdev_format *format)
+{
+	struct mt9p031 *mt9p031 = to_mt9p031(subdev);
+	struct v4l2_mbus_framefmt *__format;
+	struct v4l2_rect *__crop;
+	unsigned int width;
+	unsigned int height;
+	unsigned int hratio;
+	unsigned int vratio;
+
+	__crop = __mt9p031_get_pad_crop(mt9p031, fh, format->pad,
+					format->which);
+
+	/* Clamp the width and height to avoid dividing by zero. */
+	width = clamp_t(unsigned int, ALIGN(format->format.width, 2),
+			max(__crop->width / 7, MT9P031_WINDOW_WIDTH_MIN),
+			__crop->width);
+	height = clamp_t(unsigned int, ALIGN(format->format.height, 2),
+			max(__crop->height / 8, MT9P031_WINDOW_HEIGHT_MIN),
+			__crop->height);
+
+	hratio = DIV_ROUND_CLOSEST(__crop->width, width);
+	vratio = DIV_ROUND_CLOSEST(__crop->height, height);
+
+	__format = __mt9p031_get_pad_format(mt9p031, fh, format->pad,
+					    format->which);
+	__format->width = __crop->width / hratio;
+	__format->height = __crop->height / vratio;
+
+	format->format = *__format;
+
+	return 0;
+}
+
+static int mt9p031_get_crop(struct v4l2_subdev *subdev,
+			    struct v4l2_subdev_fh *fh,
+			    struct v4l2_subdev_crop *crop)
+{
+	struct mt9p031 *mt9p031 = to_mt9p031(subdev);
+
+	crop->rect = *__mt9p031_get_pad_crop(mt9p031, fh, crop->pad,
+					     crop->which);
+	return 0;
+}
+
+static int mt9p031_set_crop(struct v4l2_subdev *subdev,
+			    struct v4l2_subdev_fh *fh,
+			    struct v4l2_subdev_crop *crop)
+{
+	struct mt9p031 *mt9p031 = to_mt9p031(subdev);
+	struct v4l2_mbus_framefmt *__format;
+	struct v4l2_rect *__crop;
+	struct v4l2_rect rect;
+
+	/* Clamp the crop rectangle boundaries and align them to a multiple of 2
+	 * pixels to ensure a GRBG Bayer pattern.
+	 */
+	rect.left = clamp(ALIGN(crop->rect.left, 2), MT9P031_COLUMN_START_MIN,
+			  MT9P031_COLUMN_START_MAX);
+	rect.top = clamp(ALIGN(crop->rect.top, 2), MT9P031_ROW_START_MIN,
+			 MT9P031_ROW_START_MAX);
+	rect.width = clamp(ALIGN(crop->rect.width, 2),
+			   MT9P031_WINDOW_WIDTH_MIN,
+			   MT9P031_WINDOW_WIDTH_MAX);
+	rect.height = clamp(ALIGN(crop->rect.height, 2),
+			    MT9P031_WINDOW_HEIGHT_MIN,
+			    MT9P031_WINDOW_HEIGHT_MAX);
+
+	rect.width = min(rect.width, MT9P031_PIXEL_ARRAY_WIDTH - rect.left);
+	rect.height = min(rect.height, MT9P031_PIXEL_ARRAY_HEIGHT - rect.top);
+
+	__crop = __mt9p031_get_pad_crop(mt9p031, fh, crop->pad, crop->which);
+
+	if (rect.width != __crop->width || rect.height != __crop->height) {
+		/* Reset the output image size if the crop rectangle size has
+		 * been modified.
+		 */
+		__format = __mt9p031_get_pad_format(mt9p031, fh, crop->pad,
+						    crop->which);
+		__format->width = rect.width;
+		__format->height = rect.height;
+	}
+
+	*__crop = rect;
+	crop->rect = rect;
+
+	return 0;
+}
+
+/* -----------------------------------------------------------------------------
+ * V4L2 subdev control operations
+ */
+
+#define V4L2_CID_TEST_PATTERN		(V4L2_CID_USER_BASE | 0x1001)
+
+static int mt9p031_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct mt9p031 *mt9p031 =
+			container_of(ctrl->handler, struct mt9p031, ctrls);
+	struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
+	u16 data;
+	int ret;
+
+	switch (ctrl->id) {
+	case V4L2_CID_EXPOSURE:
+		ret = mt9p031_write(client, MT9P031_SHUTTER_WIDTH_UPPER,
+				    (ctrl->val >> 16) & 0xffff);
+		if (ret < 0)
+			return ret;
+
+		return mt9p031_write(client, MT9P031_SHUTTER_WIDTH_LOWER,
+				     ctrl->val & 0xffff);
+
+	case V4L2_CID_GAIN:
+		/* Gain is controlled by 2 analog stages and a digital stage.
+		 * Valid values for the 3 stages are
+		 *
+		 * Stage                Min     Max     Step
+		 * ------------------------------------------
+		 * First analog stage   x1      x2      1
+		 * Second analog stage  x1      x4      0.125
+		 * Digital stage        x1      x16     0.125
+		 *
+		 * To minimize noise, the gain stages should be used in the
+		 * second analog stage, first analog stage, digital stage order.
+		 * Gain from a previous stage should be pushed to its maximum
+		 * value before the next stage is used.
+		 */
+		if (ctrl->val <= 32) {
+			data = ctrl->val;
+		} else if (ctrl->val <= 64) {
+			ctrl->val &= ~1;
+			data = (1 << 6) | (ctrl->val >> 1);
+		} else {
+			ctrl->val &= ~7;
+			data = ((ctrl->val - 64) << 5) | (1 << 6) | 32;
+		}
+
+		return mt9p031_write(client, MT9P031_GLOBAL_GAIN, data);
+
+	case V4L2_CID_HFLIP:
+		if (ctrl->val)
+			return mt9p031_set_mode2(mt9p031,
+					0, MT9P031_READ_MODE_2_COL_MIR);
+		else
+			return mt9p031_set_mode2(mt9p031,
+					MT9P031_READ_MODE_2_COL_MIR, 0);
+
+	case V4L2_CID_VFLIP:
+		if (ctrl->val)
+			return mt9p031_set_mode2(mt9p031,
+					0, MT9P031_READ_MODE_2_ROW_MIR);
+		else
+			return mt9p031_set_mode2(mt9p031,
+					MT9P031_READ_MODE_2_ROW_MIR, 0);
+
+	case V4L2_CID_TEST_PATTERN:
+		if (!ctrl->val) {
+			ret = mt9p031_set_mode2(mt9p031,
+					0, MT9P031_READ_MODE_2_ROW_BLC);
+			if (ret < 0)
+				return ret;
+
+			return mt9p031_write(client, MT9P031_TEST_PATTERN,
+					     MT9P031_TEST_PATTERN_DISABLE);
+		}
+
+		ret = mt9p031_write(client, MT9P031_TEST_PATTERN_GREEN, 0x05a0);
+		if (ret < 0)
+			return ret;
+		ret = mt9p031_write(client, MT9P031_TEST_PATTERN_RED, 0x0a50);
+		if (ret < 0)
+			return ret;
+		ret = mt9p031_write(client, MT9P031_TEST_PATTERN_BLUE, 0x0aa0);
+		if (ret < 0)
+			return ret;
+
+		ret = mt9p031_set_mode2(mt9p031, MT9P031_READ_MODE_2_ROW_BLC,
+					0);
+		if (ret < 0)
+			return ret;
+		ret = mt9p031_write(client, MT9P031_ROW_BLACK_DEF_OFFSET, 0);
+		if (ret < 0)
+			return ret;
+
+		return mt9p031_write(client, MT9P031_TEST_PATTERN,
+				((ctrl->val - 1) << MT9P031_TEST_PATTERN_SHIFT)
+				| MT9P031_TEST_PATTERN_ENABLE);
+	}
+	return 0;
+}
+
+static struct v4l2_ctrl_ops mt9p031_ctrl_ops = {
+	.s_ctrl = mt9p031_s_ctrl,
+};
+
+static const char * const mt9p031_test_pattern_menu[] = {
+	"Disabled",
+	"Color Field",
+	"Horizontal Gradient",
+	"Vertical Gradient",
+	"Diagonal Gradient",
+	"Classic Test Pattern",
+	"Walking 1s",
+	"Monochrome Horizontal Bars",
+	"Monochrome Vertical Bars",
+	"Vertical Color Bars",
+};
+
+static const struct v4l2_ctrl_config mt9p031_ctrls[] = {
+	{
+		.ops		= &mt9p031_ctrl_ops,
+		.id		= V4L2_CID_TEST_PATTERN,
+		.type		= V4L2_CTRL_TYPE_MENU,
+		.name		= "Test Pattern",
+		.min		= 0,
+		.max		= ARRAY_SIZE(mt9p031_test_pattern_menu) - 1,
+		.step		= 0,
+		.def		= 0,
+		.flags		= 0,
+		.menu_skip_mask	= 0,
+		.qmenu		= mt9p031_test_pattern_menu,
+	}
+};
+
+/* -----------------------------------------------------------------------------
+ * V4L2 subdev core operations
+ */
+
+static int mt9p031_set_power(struct v4l2_subdev *subdev, int on)
+{
+	struct mt9p031 *mt9p031 = to_mt9p031(subdev);
+	int ret = 0;
+
+	mutex_lock(&mt9p031->power_lock);
+
+	/* If the power count is modified from 0 to != 0 or from != 0 to 0,
+	 * update the power state.
+	 */
+	if (mt9p031->power_count == !on) {
+		ret = __mt9p031_set_power(mt9p031, !!on);
+		if (ret < 0)
+			goto out;
+	}
+
+	/* Update the power count. */
+	mt9p031->power_count += on ? 1 : -1;
+	WARN_ON(mt9p031->power_count < 0);
+
+out:
+	mutex_unlock(&mt9p031->power_lock);
+	return ret;
+}
+
+/* -----------------------------------------------------------------------------
+ * V4L2 subdev internal operations
+ */
+
+static int mt9p031_registered(struct v4l2_subdev *subdev)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(subdev);
+	struct mt9p031 *mt9p031 = to_mt9p031(subdev);
+	s32 data;
+	int ret;
+
+	ret = mt9p031_power_on(mt9p031);
+	if (ret < 0) {
+		dev_err(&client->dev, "MT9P031 power up failed\n");
+		return ret;
+	}
+
+	/* Read out the chip version register */
+	data = mt9p031_read(client, MT9P031_CHIP_VERSION);
+	if (data != MT9P031_CHIP_VERSION_VALUE) {
+		dev_err(&client->dev, "MT9P031 not detected, wrong version "
+			"0x%04x\n", data);
+		return -ENODEV;
+	}
+
+	mt9p031_power_off(mt9p031);
+
+	dev_info(&client->dev, "MT9P031 detected at address 0x%02x\n",
+		 client->addr);
+
+	return ret;
+}
+
+static int mt9p031_open(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh)
+{
+	struct mt9p031 *mt9p031 = to_mt9p031(subdev);
+	struct v4l2_mbus_framefmt *format;
+	struct v4l2_rect *crop;
+
+	crop = v4l2_subdev_get_try_crop(fh, 0);
+	crop->left = MT9P031_COLUMN_START_DEF;
+	crop->top = MT9P031_ROW_START_DEF;
+	crop->width = MT9P031_WINDOW_WIDTH_DEF;
+	crop->height = MT9P031_WINDOW_HEIGHT_DEF;
+
+	format = v4l2_subdev_get_try_format(fh, 0);
+
+	if (mt9p031->pdata->version == MT9P031_MONOCHROME_VERSION)
+		format->code = V4L2_MBUS_FMT_Y12_1X12;
+	else
+		format->code = V4L2_MBUS_FMT_SGRBG12_1X12;
+
+	format->width = MT9P031_WINDOW_WIDTH_DEF;
+	format->height = MT9P031_WINDOW_HEIGHT_DEF;
+	format->field = V4L2_FIELD_NONE;
+	format->colorspace = V4L2_COLORSPACE_SRGB;
+
+	mt9p031->xskip = 1;
+	mt9p031->yskip = 1;
+	return mt9p031_set_power(subdev, 1);
+}
+
+static int mt9p031_close(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh)
+{
+	return mt9p031_set_power(subdev, 0);
+}
+
+static struct v4l2_subdev_core_ops mt9p031_subdev_core_ops = {
+	.s_power        = mt9p031_set_power,
+};
+
+static struct v4l2_subdev_video_ops mt9p031_subdev_video_ops = {
+	.s_stream       = mt9p031_s_stream,
+};
+
+static struct v4l2_subdev_pad_ops mt9p031_subdev_pad_ops = {
+	.enum_mbus_code = mt9p031_enum_mbus_code,
+	.enum_frame_size = mt9p031_enum_frame_size,
+	.get_fmt = mt9p031_get_format,
+	.set_fmt = mt9p031_set_format,
+	.get_crop = mt9p031_get_crop,
+	.set_crop = mt9p031_set_crop,
+};
+
+static struct v4l2_subdev_ops mt9p031_subdev_ops = {
+	.core   = &mt9p031_subdev_core_ops,
+	.video  = &mt9p031_subdev_video_ops,
+	.pad    = &mt9p031_subdev_pad_ops,
+};
+
+static const struct v4l2_subdev_internal_ops mt9p031_subdev_internal_ops = {
+	.registered = mt9p031_registered,
+	.open = mt9p031_open,
+	.close = mt9p031_close,
+};
+
+/* -----------------------------------------------------------------------------
+ * Driver initialization and probing
+ */
+
+static int mt9p031_probe(struct i2c_client *client,
+			 const struct i2c_device_id *did)
+{
+	struct mt9p031_platform_data *pdata = client->dev.platform_data;
+	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+	struct mt9p031 *mt9p031;
+	unsigned int i;
+	int ret;
+
+	if (pdata == NULL) {
+		dev_err(&client->dev, "No platform data\n");
+		return -EINVAL;
+	}
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
+		dev_warn(&client->dev,
+			"I2C-Adapter doesn't support I2C_FUNC_SMBUS_WORD\n");
+		return -EIO;
+	}
+
+	mt9p031 = kzalloc(sizeof(*mt9p031), GFP_KERNEL);
+	if (mt9p031 == NULL)
+		return -ENOMEM;
+
+	mt9p031->pdata = pdata;
+	mt9p031->output_control	= MT9P031_OUTPUT_CONTROL_DEF;
+	mt9p031->mode2 = MT9P031_READ_MODE_2_ROW_BLC;
+
+	v4l2_ctrl_handler_init(&mt9p031->ctrls, ARRAY_SIZE(mt9p031_ctrls) + 4);
+
+	v4l2_ctrl_new_std(&mt9p031->ctrls, &mt9p031_ctrl_ops,
+			  V4L2_CID_EXPOSURE, MT9P031_SHUTTER_WIDTH_MIN,
+			  MT9P031_SHUTTER_WIDTH_MAX, 1,
+			  MT9P031_SHUTTER_WIDTH_DEF);
+	v4l2_ctrl_new_std(&mt9p031->ctrls, &mt9p031_ctrl_ops,
+			  V4L2_CID_GAIN, MT9P031_GLOBAL_GAIN_MIN,
+			  MT9P031_GLOBAL_GAIN_MAX, 1, MT9P031_GLOBAL_GAIN_DEF);
+	v4l2_ctrl_new_std(&mt9p031->ctrls, &mt9p031_ctrl_ops,
+			  V4L2_CID_HFLIP, 0, 1, 1, 0);
+	v4l2_ctrl_new_std(&mt9p031->ctrls, &mt9p031_ctrl_ops,
+			  V4L2_CID_VFLIP, 0, 1, 1, 0);
+
+	for (i = 0; i < ARRAY_SIZE(mt9p031_ctrls); ++i)
+		v4l2_ctrl_new_custom(&mt9p031->ctrls, &mt9p031_ctrls[i], NULL);
+
+	mt9p031->subdev.ctrl_handler = &mt9p031->ctrls;
+
+	if (mt9p031->ctrls.error)
+		printk(KERN_INFO "%s: control initialization error %d\n",
+		       __func__, mt9p031->ctrls.error);
+
+	mutex_init(&mt9p031->power_lock);
+	v4l2_i2c_subdev_init(&mt9p031->subdev, client, &mt9p031_subdev_ops);
+	mt9p031->subdev.internal_ops = &mt9p031_subdev_internal_ops;
+
+	mt9p031->pad.flags = MEDIA_PAD_FL_SOURCE;
+	ret = media_entity_init(&mt9p031->subdev.entity, 1, &mt9p031->pad, 0);
+	if (ret < 0)
+		goto done;
+
+	mt9p031->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+
+	mt9p031->crop.width = MT9P031_WINDOW_WIDTH_DEF;
+	mt9p031->crop.height = MT9P031_WINDOW_HEIGHT_DEF;
+	mt9p031->crop.left = MT9P031_COLUMN_START_DEF;
+	mt9p031->crop.top = MT9P031_ROW_START_DEF;
+
+	if (mt9p031->pdata->version == MT9P031_MONOCHROME_VERSION)
+		mt9p031->format.code = V4L2_MBUS_FMT_Y12_1X12;
+	else
+		mt9p031->format.code = V4L2_MBUS_FMT_SGRBG12_1X12;
+
+	mt9p031->format.width = MT9P031_WINDOW_WIDTH_DEF;
+	mt9p031->format.height = MT9P031_WINDOW_HEIGHT_DEF;
+	mt9p031->format.field = V4L2_FIELD_NONE;
+	mt9p031->format.colorspace = V4L2_COLORSPACE_SRGB;
+
+	ret = mt9p031_pll_get_divs(mt9p031);
+
+done:
+	if (ret < 0) {
+		v4l2_ctrl_handler_free(&mt9p031->ctrls);
+		media_entity_cleanup(&mt9p031->subdev.entity);
+		kfree(mt9p031);
+	}
+
+	return ret;
+}
+
+static int mt9p031_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
+	struct mt9p031 *mt9p031 = to_mt9p031(subdev);
+
+	v4l2_ctrl_handler_free(&mt9p031->ctrls);
+	v4l2_device_unregister_subdev(subdev);
+	media_entity_cleanup(&subdev->entity);
+	kfree(mt9p031);
+
+	return 0;
+}
+
+static const struct i2c_device_id mt9p031_id[] = {
+	{ "mt9p031", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, mt9p031_id);
+
+static struct i2c_driver mt9p031_i2c_driver = {
+	.driver = {
+		.name = "mt9p031",
+	},
+	.probe          = mt9p031_probe,
+	.remove         = mt9p031_remove,
+	.id_table       = mt9p031_id,
+};
+
+static int __init mt9p031_mod_init(void)
+{
+	return i2c_add_driver(&mt9p031_i2c_driver);
+}
+
+static void __exit mt9p031_mod_exit(void)
+{
+	i2c_del_driver(&mt9p031_i2c_driver);
+}
+
+module_init(mt9p031_mod_init);
+module_exit(mt9p031_mod_exit);
+
+MODULE_DESCRIPTION("Aptina MT9P031 Camera driver");
+MODULE_AUTHOR("Bastian Hecht <hechtb@gmail.com>");
+MODULE_LICENSE("GPL v2");

include/media/mt9p031.h

+#ifndef MT9P031_H
+#define MT9P031_H
+
+struct v4l2_subdev;
+
+enum {
+	MT9P031_COLOR_VERSION,
+	MT9P031_MONOCHROME_VERSION,
+};
+
+struct mt9p031_platform_data {
+	int (*set_xclk)(struct v4l2_subdev *subdev, int hz);
+	int (*reset)(struct v4l2_subdev *subdev, int active);
+	int ext_freq; /* input frequency to the mt9p031 for PLL dividers */
+	int target_freq; /* frequency target for the PLL */
+	int version; /* MT9P031_COLOR_VERSION or MT9P031_MONOCHROME_VERSION */
+};
+
+#endif