/*
 * Driver for MT9V022 CMOS Image Sensor from Micron
 *
 * Copyright (C) 2008, Guennadi Liakhovetski <kernel@pengutronix.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/videodev2.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/log2.h>
#include <linux/module.h>

#include <media/i2c/mt9v022.h>
#include <media/soc_camera.h>
#include <media/drv-intf/soc_mediabus.h>
#include <media/v4l2-subdev.h>
#include <media/v4l2-clk.h>
#include <media/v4l2-ctrls.h>

/*
 * mt9v022 i2c address 0x48, 0x4c, 0x58, 0x5c
 * The platform has to define struct i2c_board_info objects and link to them
 * from struct soc_camera_host_desc
 */

static char *sensor_type;
module_param(sensor_type, charp, S_IRUGO);
MODULE_PARM_DESC(sensor_type, "Sensor type: \"colour\" or \"monochrome\"");

/* mt9v022 selected register addresses */
#define MT9V022_CHIP_VERSION            0x00
#define MT9V022_COLUMN_START            0x01
#define MT9V022_ROW_START               0x02
#define MT9V022_WINDOW_HEIGHT           0x03
#define MT9V022_WINDOW_WIDTH            0x04
#define MT9V022_HORIZONTAL_BLANKING     0x05
#define MT9V022_VERTICAL_BLANKING       0x06
#define MT9V022_CHIP_CONTROL            0x07
#define MT9V022_SHUTTER_WIDTH1          0x08
#define MT9V022_SHUTTER_WIDTH2          0x09
#define MT9V022_SHUTTER_WIDTH_CTRL      0x0a
#define MT9V022_TOTAL_SHUTTER_WIDTH     0x0b
#define MT9V022_RESET                   0x0c
#define MT9V022_READ_MODE               0x0d
#define MT9V022_MONITOR_MODE            0x0e
#define MT9V022_PIXEL_OPERATION_MODE    0x0f
#define MT9V022_LED_OUT_CONTROL         0x1b
#define MT9V022_ADC_MODE_CONTROL        0x1c
#define MT9V022_REG32                   0x20
#define MT9V022_ANALOG_GAIN             0x35
#define MT9V022_BLACK_LEVEL_CALIB_CTRL  0x47
#define MT9V022_PIXCLK_FV_LV            0x74
#define MT9V022_DIGITAL_TEST_PATTERN    0x7f
#define MT9V022_AEC_AGC_ENABLE          0xAF
#define MT9V022_MAX_TOTAL_SHUTTER_WIDTH 0xBD

/* mt9v024 partial list register addresses changes with respect to mt9v022 */
#define MT9V024_PIXCLK_FV_LV            0x72
#define MT9V024_MAX_TOTAL_SHUTTER_WIDTH 0xAD

/* Progressive scan, master, defaults */
#define MT9V022_CHIP_CONTROL_DEFAULT    0x188

#define MT9V022_MAX_WIDTH               752
#define MT9V022_MAX_HEIGHT              480
#define MT9V022_MIN_WIDTH               48
#define MT9V022_MIN_HEIGHT              32
#define MT9V022_COLUMN_SKIP             1
#define MT9V022_ROW_SKIP                4

#define MT9V022_HORIZONTAL_BLANKING_MIN 43
#define MT9V022_HORIZONTAL_BLANKING_MAX 1023
#define MT9V022_HORIZONTAL_BLANKING_DEF 94
#define MT9V022_VERTICAL_BLANKING_MIN   2
#define MT9V022_VERTICAL_BLANKING_MAX   3000
#define MT9V022_VERTICAL_BLANKING_DEF   45

#define is_mt9v022_rev3(id)     (id == 0x1313)
#define is_mt9v024(id)          (id == 0x1324)

/* MT9V022 has only one fixed colorspace per pixelcode */
struct mt9v022_datafmt {
        u32     code;
        enum v4l2_colorspace            colorspace;
};

/* Find a data format by a pixel code in an array */
static const struct mt9v022_datafmt *mt9v022_find_datafmt(
        u32 code, const struct mt9v022_datafmt *fmt,
        int n)
{
        int i;
        for (i = 0; i < n; i++)
                if (fmt[i].code == code)
                        return fmt + i;

        return NULL;
}

static const struct mt9v022_datafmt mt9v022_colour_fmts[] = {
        /*
         * Order important: first natively supported,
         * second supported with a GPIO extender
         */
        {MEDIA_BUS_FMT_SBGGR10_1X10, V4L2_COLORSPACE_SRGB},
        {MEDIA_BUS_FMT_SBGGR8_1X8, V4L2_COLORSPACE_SRGB},
};

static const struct mt9v022_datafmt mt9v022_monochrome_fmts[] = {
        /* Order important - see above */
        {MEDIA_BUS_FMT_Y10_1X10, V4L2_COLORSPACE_JPEG},
        {MEDIA_BUS_FMT_Y8_1X8, V4L2_COLORSPACE_JPEG},
};

/* only registers with different addresses on different mt9v02x sensors */
struct mt9v02x_register {
        u8      max_total_shutter_width;
        u8      pixclk_fv_lv;
};

static const struct mt9v02x_register mt9v022_register = {
        .max_total_shutter_width        = MT9V022_MAX_TOTAL_SHUTTER_WIDTH,
        .pixclk_fv_lv                   = MT9V022_PIXCLK_FV_LV,
};

static const struct mt9v02x_register mt9v024_register = {
        .max_total_shutter_width        = MT9V024_MAX_TOTAL_SHUTTER_WIDTH,
        .pixclk_fv_lv                   = MT9V024_PIXCLK_FV_LV,
};

enum mt9v022_model {
        MT9V022IX7ATM,
        MT9V022IX7ATC,
};

struct mt9v022 {
        struct v4l2_subdev subdev;
        struct v4l2_ctrl_handler hdl;
        struct {
                /* exposure/auto-exposure cluster */
                struct v4l2_ctrl *autoexposure;
                struct v4l2_ctrl *exposure;
        };
        struct {
                /* gain/auto-gain cluster */
                struct v4l2_ctrl *autogain;
                struct v4l2_ctrl *gain;
        };
        struct v4l2_ctrl *hblank;
        struct v4l2_ctrl *vblank;
        struct v4l2_rect rect;  /* Sensor window */
        struct v4l2_clk *clk;
        const struct mt9v022_datafmt *fmt;
        const struct mt9v022_datafmt *fmts;
        const struct mt9v02x_register *reg;
        int num_fmts;
        enum mt9v022_model model;
        u16 chip_control;
        u16 chip_version;
        unsigned short y_skip_top;      /* Lines to skip at the top */
};

static struct mt9v022 *to_mt9v022(const struct i2c_client *client)
{
        return container_of(i2c_get_clientdata(client), struct mt9v022, subdev);
}

static int reg_read(struct i2c_client *client, const u8 reg)
{
        return i2c_smbus_read_word_swapped(client, reg);
}

static int reg_write(struct i2c_client *client, const u8 reg,
                     const u16 data)
{
        return i2c_smbus_write_word_swapped(client, reg, 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 mt9v022_init(struct i2c_client *client)
{
        struct mt9v022 *mt9v022 = to_mt9v022(client);
        int ret;

        /*
         * Almost the default mode: master, parallel, simultaneous, and an
         * undocumented bit 0x200, which is present in table 7, but not in 8,
         * plus snapshot mode to disable scan for now
         */
        mt9v022->chip_control |= 0x10;
        ret = reg_write(client, MT9V022_CHIP_CONTROL, mt9v022->chip_control);
        if (!ret)
                ret = reg_write(client, MT9V022_READ_MODE, 0x300);

        /* All defaults */
        if (!ret)
                /* AEC, AGC on */
                ret = reg_set(client, MT9V022_AEC_AGC_ENABLE, 0x3);
        if (!ret)
                ret = reg_write(client, MT9V022_ANALOG_GAIN, 16);
        if (!ret)
                ret = reg_write(client, MT9V022_TOTAL_SHUTTER_WIDTH, 480);
        if (!ret)
                ret = reg_write(client, mt9v022->reg->max_total_shutter_width, 480);
        if (!ret)
                /* default - auto */
                ret = reg_clear(client, MT9V022_BLACK_LEVEL_CALIB_CTRL, 1);
        if (!ret)
                ret = reg_write(client, MT9V022_DIGITAL_TEST_PATTERN, 0);
        if (!ret)
                return v4l2_ctrl_handler_setup(&mt9v022->hdl);

        return ret;
}

static int mt9v022_s_stream(struct v4l2_subdev *sd, int enable)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct mt9v022 *mt9v022 = to_mt9v022(client);

        if (enable) {
                /* Switch to master "normal" mode */
                mt9v022->chip_control &= ~0x10;
                if (is_mt9v022_rev3(mt9v022->chip_version) ||
                    is_mt9v024(mt9v022->chip_version)) {
                        /*
                         * Unset snapshot mode specific settings: clear bit 9
                         * and bit 2 in reg. 0x20 when in normal mode.
                         */
                        if (reg_clear(client, MT9V022_REG32, 0x204))
                                return -EIO;
                }
        } else {
                /* Switch to snapshot mode */
                mt9v022->chip_control |= 0x10;
                if (is_mt9v022_rev3(mt9v022->chip_version) ||
                    is_mt9v024(mt9v022->chip_version)) {
                        /*
                         * Required settings for snapshot mode: set bit 9
                         * (RST enable) and bit 2 (CR enable) in reg. 0x20
                         * See TechNote TN0960 or TN-09-225.
                         */
                        if (reg_set(client, MT9V022_REG32, 0x204))
                                return -EIO;
                }
        }

        if (reg_write(client, MT9V022_CHIP_CONTROL, mt9v022->chip_control) < 0)
                return -EIO;
        return 0;
}

static int mt9v022_set_selection(struct v4l2_subdev *sd,
                struct v4l2_subdev_pad_config *cfg,
                struct v4l2_subdev_selection *sel)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct mt9v022 *mt9v022 = to_mt9v022(client);
        struct v4l2_rect rect = sel->r;
        int min_row, min_blank;
        int ret;

        if (sel->which != V4L2_SUBDEV_FORMAT_ACTIVE ||
            sel->target != V4L2_SEL_TGT_CROP)
                return -EINVAL;

        /* Bayer format - even size lengths */
        if (mt9v022->fmts == mt9v022_colour_fmts) {
                rect.width      = ALIGN(rect.width, 2);
                rect.height     = ALIGN(rect.height, 2);
                /* Let the user play with the starting pixel */
        }

        soc_camera_limit_side(&rect.left, &rect.width,
                     MT9V022_COLUMN_SKIP, MT9V022_MIN_WIDTH, MT9V022_MAX_WIDTH);

        soc_camera_limit_side(&rect.top, &rect.height,
                     MT9V022_ROW_SKIP, MT9V022_MIN_HEIGHT, MT9V022_MAX_HEIGHT);

        /* Like in example app. Contradicts the datasheet though */
        ret = reg_read(client, MT9V022_AEC_AGC_ENABLE);
        if (ret >= 0) {
                if (ret & 1) /* Autoexposure */
                        ret = reg_write(client, mt9v022->reg->max_total_shutter_width,
                                        rect.height + mt9v022->y_skip_top + 43);
                /*
                 * If autoexposure is off, there is no need to set
                 * MT9V022_TOTAL_SHUTTER_WIDTH here. Autoexposure can be off
                 * only if the user has set exposure manually, using the
                 * V4L2_CID_EXPOSURE_AUTO with the value V4L2_EXPOSURE_MANUAL.
                 * In this case the register MT9V022_TOTAL_SHUTTER_WIDTH
                 * already contains the correct value.
                 */
        }
        /* Setup frame format: defaults apart from width and height */
        if (!ret)
                ret = reg_write(client, MT9V022_COLUMN_START, rect.left);
        if (!ret)
                ret = reg_write(client, MT9V022_ROW_START, rect.top);
        /*
         * mt9v022: min total row time is 660 columns, min blanking is 43
         * mt9v024: min total row time is 690 columns, min blanking is 61
         */
        if (is_mt9v024(mt9v022->chip_version)) {
                min_row = 690;
                min_blank = 61;
        } else {
                min_row = 660;
                min_blank = 43;
        }
        if (!ret)
                ret = v4l2_ctrl_s_ctrl(mt9v022->hblank,
                                rect.width > min_row - min_blank ?
                                min_blank : min_row - rect.width);
        if (!ret)
                ret = v4l2_ctrl_s_ctrl(mt9v022->vblank, 45);
        if (!ret)
                ret = reg_write(client, MT9V022_WINDOW_WIDTH, rect.width);
        if (!ret)
                ret = reg_write(client, MT9V022_WINDOW_HEIGHT,
                                rect.height + mt9v022->y_skip_top);

        if (ret < 0)
                return ret;

        dev_dbg(&client->dev, "Frame %dx%d pixel\n", rect.width, rect.height);

        mt9v022->rect = rect;

        return 0;
}

static int mt9v022_get_selection(struct v4l2_subdev *sd,
                struct v4l2_subdev_pad_config *cfg,
                struct v4l2_subdev_selection *sel)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct mt9v022 *mt9v022 = to_mt9v022(client);

        if (sel->which != V4L2_SUBDEV_FORMAT_ACTIVE)
                return -EINVAL;

        switch (sel->target) {
        case V4L2_SEL_TGT_CROP_BOUNDS:
        case V4L2_SEL_TGT_CROP_DEFAULT:
                sel->r.left = MT9V022_COLUMN_SKIP;
                sel->r.top = MT9V022_ROW_SKIP;
                sel->r.width = MT9V022_MAX_WIDTH;
                sel->r.height = MT9V022_MAX_HEIGHT;
                return 0;
        case V4L2_SEL_TGT_CROP:
                sel->r = mt9v022->rect;
                return 0;
        default:
                return -EINVAL;
        }
}

static int mt9v022_get_fmt(struct v4l2_subdev *sd,
                struct v4l2_subdev_pad_config *cfg,
                struct v4l2_subdev_format *format)
{
        struct v4l2_mbus_framefmt *mf = &format->format;
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct mt9v022 *mt9v022 = to_mt9v022(client);

        if (format->pad)
                return -EINVAL;

        mf->width       = mt9v022->rect.width;
        mf->height      = mt9v022->rect.height;
        mf->code        = mt9v022->fmt->code;
        mf->colorspace  = mt9v022->fmt->colorspace;
        mf->field       = V4L2_FIELD_NONE;

        return 0;
}

static int mt9v022_s_fmt(struct v4l2_subdev *sd,
                         const struct mt9v022_datafmt *fmt,
                         struct v4l2_mbus_framefmt *mf)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct mt9v022 *mt9v022 = to_mt9v022(client);
        struct v4l2_subdev_selection sel = {
                .which = V4L2_SUBDEV_FORMAT_ACTIVE,
                .target = V4L2_SEL_TGT_CROP,
                .r.left = mt9v022->rect.left,
                .r.top = mt9v022->rect.top,
                .r.width = mf->width,
                .r.height = mf->height,
        };
        int ret;

        /*
         * The caller provides a supported format, as verified per call to
         * .set_fmt(FORMAT_TRY), datawidth is from our supported format list
         */
        switch (mf->code) {
        case MEDIA_BUS_FMT_Y8_1X8:
        case MEDIA_BUS_FMT_Y10_1X10:
                if (mt9v022->model != MT9V022IX7ATM)
                        return -EINVAL;
                break;
        case MEDIA_BUS_FMT_SBGGR8_1X8:
        case MEDIA_BUS_FMT_SBGGR10_1X10:
                if (mt9v022->model != MT9V022IX7ATC)
                        return -EINVAL;
                break;
        default:
                return -EINVAL;
        }

        /* No support for scaling on this camera, just crop. */
        ret = mt9v022_set_selection(sd, NULL, &sel);
        if (!ret) {
                mf->width       = mt9v022->rect.width;
                mf->height      = mt9v022->rect.height;
                mt9v022->fmt    = fmt;
                mf->colorspace  = fmt->colorspace;
        }

        return ret;
}

static int mt9v022_set_fmt(struct v4l2_subdev *sd,
                struct v4l2_subdev_pad_config *cfg,
                struct v4l2_subdev_format *format)
{
        struct v4l2_mbus_framefmt *mf = &format->format;
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct mt9v022 *mt9v022 = to_mt9v022(client);
        const struct mt9v022_datafmt *fmt;
        int align = mf->code == MEDIA_BUS_FMT_SBGGR8_1X8 ||
                mf->code == MEDIA_BUS_FMT_SBGGR10_1X10;

        if (format->pad)
                return -EINVAL;

        v4l_bound_align_image(&mf->width, MT9V022_MIN_WIDTH,
                MT9V022_MAX_WIDTH, align,
                &mf->height, MT9V022_MIN_HEIGHT + mt9v022->y_skip_top,
                MT9V022_MAX_HEIGHT + mt9v022->y_skip_top, align, 0);

        fmt = mt9v022_find_datafmt(mf->code, mt9v022->fmts,
                                   mt9v022->num_fmts);
        if (!fmt) {
                fmt = mt9v022->fmt;
                mf->code = fmt->code;
        }

        mf->colorspace  = fmt->colorspace;

        if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE)
                return mt9v022_s_fmt(sd, fmt, mf);
        cfg->try_fmt = *mf;
        return 0;
}

#ifdef CONFIG_VIDEO_ADV_DEBUG
static int mt9v022_g_register(struct v4l2_subdev *sd,
                              struct v4l2_dbg_register *reg)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);

        if (reg->reg > 0xff)
                return -EINVAL;

        reg->size = 2;
        reg->val = reg_read(client, reg->reg);

        if (reg->val > 0xffff)
                return -EIO;

        return 0;
}

static int mt9v022_s_register(struct v4l2_subdev *sd,
                              const struct v4l2_dbg_register *reg)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);

        if (reg->reg > 0xff)
                return -EINVAL;

        if (reg_write(client, reg->reg, reg->val) < 0)
                return -EIO;

        return 0;
}
#endif

static int mt9v022_s_power(struct v4l2_subdev *sd, int on)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct soc_camera_subdev_desc *ssdd = soc_camera_i2c_to_desc(client);
        struct mt9v022 *mt9v022 = to_mt9v022(client);

        return soc_camera_set_power(&client->dev, ssdd, mt9v022->clk, on);
}

static int mt9v022_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
{
        struct mt9v022 *mt9v022 = container_of(ctrl->handler,
                                               struct mt9v022, hdl);
        struct v4l2_subdev *sd = &mt9v022->subdev;
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct v4l2_ctrl *gain = mt9v022->gain;
        struct v4l2_ctrl *exp = mt9v022->exposure;
        unsigned long range;
        int data;

        switch (ctrl->id) {
        case V4L2_CID_AUTOGAIN:
                data = reg_read(client, MT9V022_ANALOG_GAIN);
                if (data < 0)
                        return -EIO;

                range = gain->maximum - gain->minimum;
                gain->val = ((data - 16) * range + 24) / 48 + gain->minimum;
                return 0;
        case V4L2_CID_EXPOSURE_AUTO:
                data = reg_read(client, MT9V022_TOTAL_SHUTTER_WIDTH);
                if (data < 0)
                        return -EIO;

                range = exp->maximum - exp->minimum;
                exp->val = ((data - 1) * range + 239) / 479 + exp->minimum;
                return 0;
        case V4L2_CID_HBLANK:
                data = reg_read(client, MT9V022_HORIZONTAL_BLANKING);
                if (data < 0)
                        return -EIO;
                ctrl->val = data;
                return 0;
        case V4L2_CID_VBLANK:
                data = reg_read(client, MT9V022_VERTICAL_BLANKING);
                if (data < 0)
                        return -EIO;
                ctrl->val = data;
                return 0;
        }
        return -EINVAL;
}

static int mt9v022_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct mt9v022 *mt9v022 = container_of(ctrl->handler,
                                               struct mt9v022, hdl);
        struct v4l2_subdev *sd = &mt9v022->subdev;
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        int data;

        switch (ctrl->id) {
        case V4L2_CID_VFLIP:
                if (ctrl->val)
                        data = reg_set(client, MT9V022_READ_MODE, 0x10);
                else
                        data = reg_clear(client, MT9V022_READ_MODE, 0x10);
                if (data < 0)
                        return -EIO;
                return 0;
        case V4L2_CID_HFLIP:
                if (ctrl->val)
                        data = reg_set(client, MT9V022_READ_MODE, 0x20);
                else
                        data = reg_clear(client, MT9V022_READ_MODE, 0x20);
                if (data < 0)
                        return -EIO;
                return 0;
        case V4L2_CID_AUTOGAIN:
                if (ctrl->val) {
                        if (reg_set(client, MT9V022_AEC_AGC_ENABLE, 0x2) < 0)
                                return -EIO;
                } else {
                        struct v4l2_ctrl *gain = mt9v022->gain;
                        /* mt9v022 has minimum == default */
                        unsigned long range = gain->maximum - gain->minimum;
                        /* Valid values 16 to 64, 32 to 64 must be even. */
                        unsigned long gain_val = ((gain->val - (s32)gain->minimum) *
                                              48 + range / 2) / range + 16;

                        if (gain_val >= 32)
                                gain_val &= ~1;

                        /*
                         * The user wants to set gain manually, hope, she
                         * knows, what she's doing... Switch AGC off.
                         */
                        if (reg_clear(client, MT9V022_AEC_AGC_ENABLE, 0x2) < 0)
                                return -EIO;

                        dev_dbg(&client->dev, "Setting gain from %d to %lu\n",
                                reg_read(client, MT9V022_ANALOG_GAIN), gain_val);
                        if (reg_write(client, MT9V022_ANALOG_GAIN, gain_val) < 0)
                                return -EIO;
                }
                return 0;
        case V4L2_CID_EXPOSURE_AUTO:
                if (ctrl->val == V4L2_EXPOSURE_AUTO) {
                        data = reg_set(client, MT9V022_AEC_AGC_ENABLE, 0x1);
                } else {
                        struct v4l2_ctrl *exp = mt9v022->exposure;
                        unsigned long range = exp->maximum - exp->minimum;
                        unsigned long shutter = ((exp->val - (s32)exp->minimum) *
                                        479 + range / 2) / range + 1;

                        /*
                         * The user wants to set shutter width manually, hope,
                         * she knows, what she's doing... Switch AEC off.
                         */
                        data = reg_clear(client, MT9V022_AEC_AGC_ENABLE, 0x1);
                        if (data < 0)
                                return -EIO;
                        dev_dbg(&client->dev, "Shutter width from %d to %lu\n",
                                        reg_read(client, MT9V022_TOTAL_SHUTTER_WIDTH),
                                        shutter);
                        if (reg_write(client, MT9V022_TOTAL_SHUTTER_WIDTH,
                                                shutter) < 0)
                                return -EIO;
                }
                return 0;
        case V4L2_CID_HBLANK:
                if (reg_write(client, MT9V022_HORIZONTAL_BLANKING,
                                ctrl->val) < 0)
                        return -EIO;
                return 0;
        case V4L2_CID_VBLANK:
                if (reg_write(client, MT9V022_VERTICAL_BLANKING,
                                ctrl->val) < 0)
                        return -EIO;
                return 0;
        }
        return -EINVAL;
}

/*
 * Interface active, can use i2c. If it fails, it can indeed mean, that
 * this wasn't our capture interface, so, we wait for the right one
 */
static int mt9v022_video_probe(struct i2c_client *client)
{
        struct mt9v022 *mt9v022 = to_mt9v022(client);
        struct soc_camera_subdev_desc *ssdd = soc_camera_i2c_to_desc(client);
        s32 data;
        int ret;
        unsigned long flags;

        ret = mt9v022_s_power(&mt9v022->subdev, 1);
        if (ret < 0)
                return ret;

        /* Read out the chip version register */
        data = reg_read(client, MT9V022_CHIP_VERSION);

        /* must be 0x1311, 0x1313 or 0x1324 */
        if (data != 0x1311 && data != 0x1313 && data != 0x1324) {
                ret = -ENODEV;
                dev_info(&client->dev, "No MT9V022 found, ID register 0x%x\n",
                         data);
                goto ei2c;
        }

        mt9v022->chip_version = data;

        mt9v022->reg = is_mt9v024(data) ? &mt9v024_register :
                        &mt9v022_register;

        /* Soft reset */
        ret = reg_write(client, MT9V022_RESET, 1);
        if (ret < 0)
                goto ei2c;
        /* 15 clock cycles */
        udelay(200);
        if (reg_read(client, MT9V022_RESET)) {
                dev_err(&client->dev, "Resetting MT9V022 failed!\n");
                if (ret > 0)
                        ret = -EIO;
                goto ei2c;
        }

        /* Set monochrome or colour sensor type */
        if (sensor_type && (!strcmp("colour", sensor_type) ||
                            !strcmp("color", sensor_type))) {
                ret = reg_write(client, MT9V022_PIXEL_OPERATION_MODE, 4 | 0x11);
                mt9v022->model = MT9V022IX7ATC;
                mt9v022->fmts = mt9v022_colour_fmts;
        } else {
                ret = reg_write(client, MT9V022_PIXEL_OPERATION_MODE, 0x11);
                mt9v022->model = MT9V022IX7ATM;
                mt9v022->fmts = mt9v022_monochrome_fmts;
        }

        if (ret < 0)
                goto ei2c;

        mt9v022->num_fmts = 0;

        /*
         * This is a 10bit sensor, so by default we only allow 10bit.
         * The platform may support different bus widths due to
         * different routing of the data lines.
         */
        if (ssdd->query_bus_param)
                flags = ssdd->query_bus_param(ssdd);
        else
                flags = SOCAM_DATAWIDTH_10;

        if (flags & SOCAM_DATAWIDTH_10)
                mt9v022->num_fmts++;
        else
                mt9v022->fmts++;

        if (flags & SOCAM_DATAWIDTH_8)
                mt9v022->num_fmts++;

        mt9v022->fmt = &mt9v022->fmts[0];

        dev_info(&client->dev, "Detected a MT9V022 chip ID %x, %s sensor\n",
                 data, mt9v022->model == MT9V022IX7ATM ?
                 "monochrome" : "colour");

        ret = mt9v022_init(client);
        if (ret < 0)
                dev_err(&client->dev, "Failed to initialise the camera\n");

ei2c:
        mt9v022_s_power(&mt9v022->subdev, 0);
        return ret;
}

static int mt9v022_g_skip_top_lines(struct v4l2_subdev *sd, u32 *lines)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct mt9v022 *mt9v022 = to_mt9v022(client);

        *lines = mt9v022->y_skip_top;

        return 0;
}

static const struct v4l2_ctrl_ops mt9v022_ctrl_ops = {
        .g_volatile_ctrl = mt9v022_g_volatile_ctrl,
        .s_ctrl = mt9v022_s_ctrl,
};

static const struct v4l2_subdev_core_ops mt9v022_subdev_core_ops = {
#ifdef CONFIG_VIDEO_ADV_DEBUG
        .g_register     = mt9v022_g_register,
        .s_register     = mt9v022_s_register,
#endif
        .s_power        = mt9v022_s_power,
};

static int mt9v022_enum_mbus_code(struct v4l2_subdev *sd,
                struct v4l2_subdev_pad_config *cfg,
                struct v4l2_subdev_mbus_code_enum *code)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct mt9v022 *mt9v022 = to_mt9v022(client);

        if (code->pad || code->index >= mt9v022->num_fmts)
                return -EINVAL;

        code->code = mt9v022->fmts[code->index].code;
        return 0;
}

static int mt9v022_g_mbus_config(struct v4l2_subdev *sd,
                                struct v4l2_mbus_config *cfg)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct soc_camera_subdev_desc *ssdd = soc_camera_i2c_to_desc(client);

        cfg->flags = V4L2_MBUS_MASTER | V4L2_MBUS_SLAVE |
                V4L2_MBUS_PCLK_SAMPLE_RISING | V4L2_MBUS_PCLK_SAMPLE_FALLING |
                V4L2_MBUS_HSYNC_ACTIVE_HIGH | V4L2_MBUS_HSYNC_ACTIVE_LOW |
                V4L2_MBUS_VSYNC_ACTIVE_HIGH | V4L2_MBUS_VSYNC_ACTIVE_LOW |
                V4L2_MBUS_DATA_ACTIVE_HIGH;
        cfg->type = V4L2_MBUS_PARALLEL;
        cfg->flags = soc_camera_apply_board_flags(ssdd, cfg);

        return 0;
}

static int mt9v022_s_mbus_config(struct v4l2_subdev *sd,
                                 const struct v4l2_mbus_config *cfg)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct soc_camera_subdev_desc *ssdd = soc_camera_i2c_to_desc(client);
        struct mt9v022 *mt9v022 = to_mt9v022(client);
        unsigned long flags = soc_camera_apply_board_flags(ssdd, cfg);
        unsigned int bps = soc_mbus_get_fmtdesc(mt9v022->fmt->code)->bits_per_sample;
        int ret;
        u16 pixclk = 0;

        if (ssdd->set_bus_param) {
                ret = ssdd->set_bus_param(ssdd, 1 << (bps - 1));
                if (ret)
                        return ret;
        } else if (bps != 10) {
                /*
                 * Without board specific bus width settings we only support the
                 * sensors native bus width
                 */
                return -EINVAL;
        }

        if (flags & V4L2_MBUS_PCLK_SAMPLE_FALLING)
                pixclk |= 0x10;

        if (!(flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH))
                pixclk |= 0x1;

        if (!(flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH))
                pixclk |= 0x2;

        ret = reg_write(client, mt9v022->reg->pixclk_fv_lv, pixclk);
        if (ret < 0)
                return ret;

        if (!(flags & V4L2_MBUS_MASTER))
                mt9v022->chip_control &= ~0x8;

        ret = reg_write(client, MT9V022_CHIP_CONTROL, mt9v022->chip_control);
        if (ret < 0)
                return ret;

        dev_dbg(&client->dev, "Calculated pixclk 0x%x, chip control 0x%x\n",
                pixclk, mt9v022->chip_control);

        return 0;
}

static const struct v4l2_subdev_video_ops mt9v022_subdev_video_ops = {
        .s_stream       = mt9v022_s_stream,
        .g_mbus_config  = mt9v022_g_mbus_config,
        .s_mbus_config  = mt9v022_s_mbus_config,
};

static const struct v4l2_subdev_sensor_ops mt9v022_subdev_sensor_ops = {
        .g_skip_top_lines       = mt9v022_g_skip_top_lines,
};

static const struct v4l2_subdev_pad_ops mt9v022_subdev_pad_ops = {
        .enum_mbus_code = mt9v022_enum_mbus_code,
        .get_selection  = mt9v022_get_selection,
        .set_selection  = mt9v022_set_selection,
        .get_fmt        = mt9v022_get_fmt,
        .set_fmt        = mt9v022_set_fmt,
};

static const struct v4l2_subdev_ops mt9v022_subdev_ops = {
        .core   = &mt9v022_subdev_core_ops,
        .video  = &mt9v022_subdev_video_ops,
        .sensor = &mt9v022_subdev_sensor_ops,
        .pad    = &mt9v022_subdev_pad_ops,
};

static int mt9v022_probe(struct i2c_client *client,
                         const struct i2c_device_id *did)
{
        struct mt9v022 *mt9v022;
        struct soc_camera_subdev_desc *ssdd = soc_camera_i2c_to_desc(client);
        struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
        struct mt9v022_platform_data *pdata;
        int ret;

        if (!ssdd) {
                dev_err(&client->dev, "MT9V022 driver needs platform data\n");
                return -EINVAL;
        }

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
                dev_warn(&adapter->dev,
                         "I2C-Adapter doesn't support I2C_FUNC_SMBUS_WORD\n");
                return -EIO;
        }

        mt9v022 = devm_kzalloc(&client->dev, sizeof(struct mt9v022), GFP_KERNEL);
        if (!mt9v022)
                return -ENOMEM;

        pdata = ssdd->drv_priv;
        v4l2_i2c_subdev_init(&mt9v022->subdev, client, &mt9v022_subdev_ops);
        v4l2_ctrl_handler_init(&mt9v022->hdl, 6);
        v4l2_ctrl_new_std(&mt9v022->hdl, &mt9v022_ctrl_ops,
                        V4L2_CID_VFLIP, 0, 1, 1, 0);
        v4l2_ctrl_new_std(&mt9v022->hdl, &mt9v022_ctrl_ops,
                        V4L2_CID_HFLIP, 0, 1, 1, 0);
        mt9v022->autogain = v4l2_ctrl_new_std(&mt9v022->hdl, &mt9v022_ctrl_ops,
                        V4L2_CID_AUTOGAIN, 0, 1, 1, 1);
        mt9v022->gain = v4l2_ctrl_new_std(&mt9v022->hdl, &mt9v022_ctrl_ops,
                        V4L2_CID_GAIN, 0, 127, 1, 64);

        /*
         * Simulated autoexposure. If enabled, we calculate shutter width
         * ourselves in the driver based on vertical blanking and frame width
         */
        mt9v022->autoexposure = v4l2_ctrl_new_std_menu(&mt9v022->hdl,
                        &mt9v022_ctrl_ops, V4L2_CID_EXPOSURE_AUTO, 1, 0,
                        V4L2_EXPOSURE_AUTO);
        mt9v022->exposure = v4l2_ctrl_new_std(&mt9v022->hdl, &mt9v022_ctrl_ops,
                        V4L2_CID_EXPOSURE, 1, 255, 1, 255);

        mt9v022->hblank = v4l2_ctrl_new_std(&mt9v022->hdl, &mt9v022_ctrl_ops,
                        V4L2_CID_HBLANK, MT9V022_HORIZONTAL_BLANKING_MIN,
                        MT9V022_HORIZONTAL_BLANKING_MAX, 1,
                        MT9V022_HORIZONTAL_BLANKING_DEF);

        mt9v022->vblank = v4l2_ctrl_new_std(&mt9v022->hdl, &mt9v022_ctrl_ops,
                        V4L2_CID_VBLANK, MT9V022_VERTICAL_BLANKING_MIN,
                        MT9V022_VERTICAL_BLANKING_MAX, 1,
                        MT9V022_VERTICAL_BLANKING_DEF);

        mt9v022->subdev.ctrl_handler = &mt9v022->hdl;
        if (mt9v022->hdl.error) {
                int err = mt9v022->hdl.error;

                dev_err(&client->dev, "control initialisation err %d\n", err);
                return err;
        }
        v4l2_ctrl_auto_cluster(2, &mt9v022->autoexposure,
                                V4L2_EXPOSURE_MANUAL, true);
        v4l2_ctrl_auto_cluster(2, &mt9v022->autogain, 0, true);

        mt9v022->chip_control = MT9V022_CHIP_CONTROL_DEFAULT;

        /*
         * On some platforms the first read out line is corrupted.
         * Workaround it by skipping if indicated by platform data.
         */
        mt9v022->y_skip_top     = pdata ? pdata->y_skip_top : 0;
        mt9v022->rect.left      = MT9V022_COLUMN_SKIP;
        mt9v022->rect.top       = MT9V022_ROW_SKIP;
        mt9v022->rect.width     = MT9V022_MAX_WIDTH;
        mt9v022->rect.height    = MT9V022_MAX_HEIGHT;

        mt9v022->clk = v4l2_clk_get(&client->dev, "mclk");
        if (IS_ERR(mt9v022->clk)) {
                ret = PTR_ERR(mt9v022->clk);
                goto eclkget;
        }

        ret = mt9v022_video_probe(client);
        if (ret) {
                v4l2_clk_put(mt9v022->clk);
eclkget:
                v4l2_ctrl_handler_free(&mt9v022->hdl);
        }

        return ret;
}

static int mt9v022_remove(struct i2c_client *client)
{
        struct mt9v022 *mt9v022 = to_mt9v022(client);
        struct soc_camera_subdev_desc *ssdd = soc_camera_i2c_to_desc(client);

        v4l2_clk_put(mt9v022->clk);
        v4l2_device_unregister_subdev(&mt9v022->subdev);
        if (ssdd->free_bus)
                ssdd->free_bus(ssdd);
        v4l2_ctrl_handler_free(&mt9v022->hdl);

        return 0;
}
static const struct i2c_device_id mt9v022_id[] = {
        { "mt9v022", 0 },
        { }
};
MODULE_DEVICE_TABLE(i2c, mt9v022_id);

static struct i2c_driver mt9v022_i2c_driver = {

        .driver = {
                .name = "mt9v022",
        },
        .probe          = mt9v022_probe,
        .remove         = mt9v022_remove,
        .id_table       = mt9v022_id,
};

module_i2c_driver(mt9v022_i2c_driver);

MODULE_DESCRIPTION("Micron MT9V022 Camera driver");
MODULE_AUTHOR("Guennadi Liakhovetski <kernel@pengutronix.de>");
MODULE_LICENSE("GPL");