path: root/drivers/media/video/mt9t031.c

/*
 * Driver for MT9T031 CMOS Image Sensor from Micron
 *
 * Copyright (C) 2008, Guennadi Liakhovetski, DENX Software Engineering <lg@denx.de>
 *
 * 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/device.h>
#include <linux/i2c.h>
#include <linux/log2.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/videodev2.h>

#include <media/soc_camera.h>
#include <media/v4l2-chip-ident.h>
#include <media/v4l2-subdev.h>

/*
 * mt9t031 i2c address 0x5d
 * The platform has to define i2c_board_info and link to it from
 * struct soc_camera_link
 */

/* mt9t031 selected register addresses */
#define MT9T031_CHIP_VERSION		0x00
#define MT9T031_ROW_START		0x01
#define MT9T031_COLUMN_START		0x02
#define MT9T031_WINDOW_HEIGHT		0x03
#define MT9T031_WINDOW_WIDTH		0x04
#define MT9T031_HORIZONTAL_BLANKING	0x05
#define MT9T031_VERTICAL_BLANKING	0x06
#define MT9T031_OUTPUT_CONTROL		0x07
#define MT9T031_SHUTTER_WIDTH_UPPER	0x08
#define MT9T031_SHUTTER_WIDTH		0x09
#define MT9T031_PIXEL_CLOCK_CONTROL	0x0a
#define MT9T031_FRAME_RESTART		0x0b
#define MT9T031_SHUTTER_DELAY		0x0c
#define MT9T031_RESET			0x0d
#define MT9T031_READ_MODE_1		0x1e
#define MT9T031_READ_MODE_2		0x20
#define MT9T031_READ_MODE_3		0x21
#define MT9T031_ROW_ADDRESS_MODE	0x22
#define MT9T031_COLUMN_ADDRESS_MODE	0x23
#define MT9T031_GLOBAL_GAIN		0x35
#define MT9T031_CHIP_ENABLE		0xF8

#define MT9T031_MAX_HEIGHT		1536
#define MT9T031_MAX_WIDTH		2048
#define MT9T031_MIN_HEIGHT		2
#define MT9T031_MIN_WIDTH		18
#define MT9T031_HORIZONTAL_BLANK	142
#define MT9T031_VERTICAL_BLANK		25
#define MT9T031_COLUMN_SKIP		32
#define MT9T031_ROW_SKIP		20

#define MT9T031_BUS_PARAM	(SOCAM_PCLK_SAMPLE_RISING |	\
	SOCAM_PCLK_SAMPLE_FALLING | SOCAM_HSYNC_ACTIVE_HIGH |	\
	SOCAM_VSYNC_ACTIVE_HIGH | SOCAM_DATA_ACTIVE_HIGH |	\
	SOCAM_MASTER | SOCAM_DATAWIDTH_10)

struct mt9t031 {
	struct v4l2_subdev subdev;
	struct v4l2_rect rect;	/* Sensor window */
	int model;	/* V4L2_IDENT_MT9T031* codes from v4l2-chip-ident.h */
	u16 xskip;
	u16 yskip;
	unsigned int gain;
	unsigned short y_skip_top;	/* Lines to skip at the top */
	unsigned int exposure;
	unsigned char autoexposure;
};

static struct mt9t031 *to_mt9t031(const struct i2c_client *client)
{
	return container_of(i2c_get_clientdata(client), struct mt9t031, subdev);
}

static int reg_read(struct i2c_client *client, const u8 reg)
{
	s32 data = i2c_smbus_read_word_data(client, reg);
	return data < 0 ? data : swab16(data);
}

static int reg_write(struct i2c_client *client, const u8 reg,
		     const u16 data)
{
	return i2c_smbus_write_word_data(client, reg, swab16(data));
}

static int reg_set(struct i2c_client *client, const u8 reg,
		   const u16 data)
{
	int ret;

	ret = reg_read(client, reg);
	if (ret < 0)
		return ret;
	return reg_write(client, reg, ret | data);
}

static int reg_clear(struct i2c_client *client, const u8 reg,
		     const u16 data)
{
	int ret;

	ret = reg_read(client, reg);
	if (ret < 0)
		return ret;
	return reg_write(client, reg, ret & ~data);
}

static int set_shutter(struct i2c_client *client, const u32 data)
{
	int ret;

	ret = reg_write(client, MT9T031_SHUTTER_WIDTH_UPPER, data >> 16);

	if (ret >= 0)
		ret = reg_write(client, MT9T031_SHUTTER_WIDTH, data & 0xffff);

	return ret;
}

static int get_shutter(struct i2c_client *client, u32 *data)
{
	int ret;

	ret = reg_read(client, MT9T031_SHUTTER_WIDTH_UPPER);
	*data = ret << 16;

	if (ret >= 0)
		ret = reg_read(client, MT9T031_SHUTTER_WIDTH);
	*data |= ret & 0xffff;

	return ret < 0 ? ret : 0;
}

static int mt9t031_idle(struct i2c_client *client)
{
	int ret;

	/* Disable chip output, synchronous option update */
	ret = reg_write(client, MT9T031_RESET, 1);
	if (ret >= 0)
		ret = reg_write(client, MT9T031_RESET, 0);
	if (ret >= 0)
		ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);

	return ret >= 0 ? 0 : -EIO;
}

static int mt9t031_disable(struct i2c_client *client)
{
	/* Disable the chip */
	reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);

	return 0;
}

static int mt9t031_s_stream(struct v4l2_subdev *sd, int enable)
{
	struct i2c_client *client = sd->priv;
	int ret;

	if (enable)
		/* Switch to master "normal" mode */
		ret = reg_set(client, MT9T031_OUTPUT_CONTROL, 2);
	else
		/* Stop sensor readout */
		ret = reg_clear(client, MT9T031_OUTPUT_CONTROL, 2);

	if (ret < 0)
		return -EIO;

	return 0;
}

static int mt9t031_set_bus_param(struct soc_camera_device *icd,
				 unsigned long flags)
{
	struct i2c_client