/*
 * Driver for MT9M001 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/log2.h>
#include <linux/module.h>

#include <media/soc_camera.h>
#include <media/soc_mediabus.h>
#include <media/v4l2-clk.h>
#include <media/v4l2-subdev.h>
#include <media/v4l2-ctrls.h>

/*
 * mt9m001 i2c address 0x5d
 * The platform has to define struct i2c_board_info objects and link to them
 * from struct soc_camera_host_desc
 */

/* mt9m001 selected register addresses */
#define MT9M001_CHIP_VERSION            0x00
#define MT9M001_ROW_START               0x01
#define MT9M001_COLUMN_START            0x02
#define MT9M001_WINDOW_HEIGHT           0x03
#define MT9M001_WINDOW_WIDTH            0x04
#define MT9M001_HORIZONTAL_BLANKING     0x05
#define MT9M001_VERTICAL_BLANKING       0x06
#define MT9M001_OUTPUT_CONTROL          0x07
#define MT9M001_SHUTTER_WIDTH           0x09
#define MT9M001_FRAME_RESTART           0x0b
#define MT9M001_SHUTTER_DELAY           0x0c
#define MT9M001_RESET                   0x0d
#define MT9M001_READ_OPTIONS1           0x1e
#define MT9M001_READ_OPTIONS2           0x20
#define MT9M001_GLOBAL_GAIN             0x35
#define MT9M001_CHIP_ENABLE             0xF1

#define MT9M001_MAX_WIDTH               1280
#define MT9M001_MAX_HEIGHT              1024
#define MT9M001_MIN_WIDTH               48
#define MT9M001_MIN_HEIGHT              32
#define MT9M001_COLUMN_SKIP             20
#define MT9M001_ROW_SKIP                12

/* MT9M001 has only one fixed colorspace per pixelcode */
struct mt9m001_datafmt {
        u32     code;
        enum v4l2_colorspace            colorspace;
};

/* Find a data format by a pixel code in an array */
static const struct mt9m001_datafmt *mt9m001_find_datafmt(
        u32 code, const struct mt9m001_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 mt9m001_datafmt mt9m001_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 mt9m001_datafmt mt9m001_monochrome_fmts[] = {
        /* Order important - see above */
        {MEDIA_BUS_FMT_Y10_1X10, V4L2_COLORSPACE_JPEG},
        {MEDIA_BUS_FMT_Y8_1X8, V4L2_COLORSPACE_JPEG},
};

struct mt9m001 {
        struct v4l2_subdev subdev;
        struct v4l2_ctrl_handler hdl;
        struct {
                /* exposure/auto-exposure cluster */
                struct v4l2_ctrl *autoexposure;
                struct v4l2_ctrl *exposure;
        };
        struct v4l2_rect rect;  /* Sensor window */
        struct v4l2_clk *clk;
        const struct mt9m001_datafmt *fmt;
        const struct mt9m001_datafmt *fmts;
        int num_fmts;
        unsigned int total_h;
        unsigned short y_skip_top;      /* Lines to skip at the top */
};

static struct mt9m001 *to_mt9m001(const struct i2c_client *client)
{
        return container_of(i2c_get_clientdata(client), struct mt9m001, 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 mt9m001_init(struct i2c_client *client)
{
        int ret;

        dev_dbg(&client->dev, "%s\n", __func__);

        /*
         * We don't know, whether platform provides reset, issue a soft reset
         * too. This returns all registers to their default values.
         */
        ret = reg_write(client, MT9M001_RESET, 1);
        if (!ret)
                ret = reg_write(client, MT9M001_RESET, 0);

        /* Disable chip, synchronous option update */
        if (!ret)
                ret = reg_write(client, MT9M001_OUTPUT_CONTROL, 0);

        return ret;
}

static int mt9m001_s_stream(struct v4l2_subdev *sd, int enable)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);

        /* Switch to master "normal" mode or stop sensor readout */
        if (reg_write(client, MT9M001_OUTPUT_CONTROL, enable ? 2 : 0) < 0)
                return -EIO;
        return 0;
}

static int mt9m001_s_crop(struct v4l2_subdev *sd, const struct v4l2_crop *a)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct mt9m001 *mt9m001 = to_mt9m001(client);
        struct v4l2_rect rect = a->c;
        int ret;
        const u16 hblank = 9, vblank = 25;

        if (mt9m001->fmts == mt9m001_colour_fmts)
                /*
                 * Bayer format - even number of rows for simplicity,
                 * but let the user play with the top row.
                 */
                rect.height = ALIGN(rect.height, 2);

        /* Datasheet requirement: see register description */
        rect.width = ALIGN(rect.width, 2);
        rect.left = ALIGN(rect.left, 2);

        soc_camera_limit_side(&rect.left, &rect.width,
                     MT9M001_COLUMN_SKIP, MT9M001_MIN_WIDTH, MT9M001_MAX_WIDTH);

        soc_camera_limit_side(&rect.top, &rect.height,
                     MT9M001_ROW_SKIP, MT9M001_MIN_HEIGHT, MT9M001_MAX_HEIGHT);

        mt9m001->total_h = rect.height + mt9m001->y_skip_top + vblank;

        /* Blanking and start values - default... */
        ret = reg_write(client, MT9M001_HORIZONTAL_BLANKING, hblank);
        if (!ret)
                ret = reg_write(client, MT9M001_VERTICAL_BLANKING, vblank);

        /*
         * The caller provides a supported format, as verified per
         * call to .try_mbus_fmt()
         */
        if (!ret)
                ret = reg_write(client, MT9M001_COLUMN_START, rect.left);
        if (!ret)
                ret = reg_write(client, MT9M001_ROW_START, rect.top);
        if (!ret)
                ret = reg_write(client, MT9M001_WINDOW_WIDTH, rect.width - 1);
        if (!ret)
                ret = reg_write(client, MT9M001_WINDOW_HEIGHT,
                                rect.height + mt9m001->y_skip_top - 1);
        if (!ret && v4l2_ctrl_g_ctrl(mt9m001->autoexposure) == V4L2_EXPOSURE_AUTO)
                ret = reg_write(client, MT9M001_SHUTTER_WIDTH, mt9m001->total_h);

        if (!ret)
                mt9m001->rect = rect;

        return ret;
}

static int mt9m001_g_crop(struct v4l2_subdev *sd, struct v4l2_crop *a)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct mt9m001 *mt9m001 = to_mt9m001(client);

        a->c    = mt9m001->rect;
        a->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

        return 0;
}

static int mt9m001_cropcap(struct v4l2_subdev *sd, struct v4l2_cropcap *a)
{
        a->bounds.left                  = MT9M001_COLUMN_SKIP;
        a->bounds.top                   = MT9M001_ROW_SKIP;
        a->bounds.width                 = MT9M001_MAX_WIDTH;
        a->bounds.height                = MT9M001_MAX_HEIGHT;
        a->defrect                      = a->bounds;
        a->type                         = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        a->pixelaspect.numerator        = 1;
        a->pixelaspect.denominator      = 1;

        return 0;
}

static int mt9m001_g_fmt(struct v4l2_subdev *sd,
                         struct v4l2_mbus_framefmt *mf)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct mt9m001 *mt9m001 = to_mt9m001(client);

        mf->width       = mt9m001->rect.width;
        mf->height      = mt9m001->rect.height;
        mf->code        = mt9m001->fmt->code;
        mf->colorspace  = mt9m001->fmt->colorspace;
        mf->field       = V4L2_FIELD_NONE;

        return 0;
}

static int mt9m001_s_fmt(struct v4l2_subdev *sd,
                         struct v4l2_mbus_framefmt *mf)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct mt9m001 *mt9m001 = to_mt9m001(client);
        struct v4l2_crop a = {
                .c = {
                        .left   = mt9m001->rect.left,
                        .top    = mt9m001->rect.top,
                        .width  = mf->width,
                        .height = mf->height,
                },
        };
        int ret;

        /* No support for scaling so far, just crop. TODO: use skipping */
        ret = mt9m001_s_crop(sd, &a);
        if (!ret) {
                mf->width       = mt9m001->rect.width;
                mf->height      = mt9m001->rect.height;
                mt9m001->fmt    = mt9m001_find_datafmt(mf->code,
                                        mt9m001->fmts, mt9m001->num_fmts);
                mf->colorspace  = mt9m001->fmt->colorspace;
        }

        return ret;
}

static int mt9m001_try_fmt(struct v4l2_subdev *sd,
                           struct v4l2_mbus_framefmt *mf)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct mt9m001 *mt9m001 = to_mt9m001(client);
        const struct mt9m001_datafmt *fmt;

        v4l_bound_align_image(&mf->width, MT9M001_MIN_WIDTH,
                MT9M001_MAX_WIDTH, 1,
                &mf->height, MT9M001_MIN_HEIGHT + mt9m001->y_skip_top,
                MT9M001_MAX_HEIGHT + mt9m001->y_skip_top, 0, 0);

        if (mt9m001->fmts == mt9m001_colour_fmts)
                mf->height = ALIGN(mf->height - 1, 2);

        fmt = mt9m001_find_datafmt(mf->code, mt9m001->fmts,
                                   mt9m001->num_fmts);
        if (!fmt) {
                fmt = mt9m001->fmt;
                mf->code = fmt->code;
        }

        mf->colorspace  = fmt->colorspace;

        return 0;
}

#ifdef CONFIG_VIDEO_ADV_DEBUG
static int mt9m001_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 mt9m001_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 mt9m001_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 mt9m001 *mt9m001 = to_mt9m001(client);

        return soc_camera_set_power(&client->dev, ssdd, mt9m001->clk, on);
}

static int mt9m001_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
{
        struct mt9m001 *mt9m001 = container_of(ctrl->handler,
                                               struct mt9m001, hdl);
        s32 min, max;

        switch (ctrl->id) {
        case V4L2_CID_EXPOSURE_AUTO:
                min = mt9m001->exposure->minimum;
                max = mt9m001->exposure->maximum;
                mt9m001->exposure->val =
                        (524 + (mt9m001->total_h - 1) * (max - min)) / 1048 + min;
                break;
        }
        return 0;
}

static int mt9m001_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct mt9m001 *mt9m001 = container_of(ctrl->handler,
                                               struct mt9m001, hdl);
        struct v4l2_subdev *sd = &mt9m001->subdev;
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct v4l2_ctrl *exp = mt9m001->exposure;
        int data;

        switch (ctrl->id) {
        case V4L2_CID_VFLIP:
                if (ctrl->val)
                        data = reg_set(client, MT9M001_READ_OPTIONS2, 0x8000);
                else
                        data = reg_clear(client, MT9M001_READ_OPTIONS2, 0x8000);
                if (data < 0)
                        return -EIO;
                return 0;

        case V4L2_CID_GAIN:
                /* See Datasheet Table 7, Gain settings. */
                if (ctrl->val <= ctrl->default_value) {
                        /* Pack it into 0..1 step 0.125, register values 0..8 */
                        unsigned long range = ctrl->default_value - ctrl->minimum;
                        data = ((ctrl->val - (s32)ctrl->minimum) * 8 + range / 2) / range;

                        dev_dbg(&client->dev, "Setting gain %d\n", data);
                        data = reg_write(client, MT9M001_GLOBAL_GAIN, data);
                        if (data < 0)
                                return -EIO;
                } else {
                        /* Pack it into 1.125..15 variable step, register values 9..67 */
                        /* We assume qctrl->maximum - qctrl->default_value - 1 > 0 */
                        unsigned long range = ctrl->maximum - ctrl->default_value - 1;
                        unsigned long gain = ((ctrl->val - (s32)ctrl->default_value - 1) *
                                               111 + range / 2) / range + 9;

                        if (gain <= 32)
                                data = gain;
                        else if (gain <= 64)
                                data = ((gain - 32) * 16 + 16) / 32 + 80;
                        else
                                data = ((gain - 64) * 7 + 28) / 56 + 96;

                        dev_dbg(&client->dev, "Setting gain from %d to %d\n",
                                 reg_read(client, MT9M001_GLOBAL_GAIN), data);
                        data = reg_write(client, MT9M001_GLOBAL_GAIN, data);
                        if (data < 0)
                                return -EIO;
                }
                return 0;

        case V4L2_CID_EXPOSURE_AUTO:
                if (ctrl->val == V4L2_EXPOSURE_MANUAL) {
                        unsigned long range = exp->maximum - exp->minimum;
                        unsigned long shutter = ((exp->val - (s32)exp->minimum) * 1048 +
                                                 range / 2) / range + 1;

                        dev_dbg(&client->dev,
                                "Setting shutter width from %d to %lu\n",
                                reg_read(client, MT9M001_SHUTTER_WIDTH), shutter);
                        if (reg_write(client, MT9M001_SHUTTER_WIDTH, shutter) < 0)
                                return -EIO;
                } else {
                        const u16 vblank = 25;

                        mt9m001->total_h = mt9m001->rect.height +
                                mt9m001->y_skip_top + vblank;
                        if (reg_write(client, MT9M001_SHUTTER_WIDTH, mt9m001->total_h) < 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 mt9m001_video_probe(struct soc_camera_subdev_desc *ssdd,
                               struct i2c_client *client)
{
        struct mt9m001 *mt9m001 = to_mt9m001(client);
        s32 data;
        unsigned long flags;
        int ret;

        ret = mt9m001_s_power(&mt9m001->subdev, 1);
        if (ret < 0)
                return ret;

        /* Enable the chip */
        data = reg_write(client, MT9M001_CHIP_ENABLE, 1);
        dev_dbg(&client->dev, "write: %d\n", data);

        /* Read out the chip version register */
        data = reg_read(client, MT9M001_CHIP_VERSION);

        /* must be 0x8411 or 0x8421 for colour sensor and 8431 for bw */
        switch (data) {
        case 0x8411:
        case 0x8421:
                mt9m001->fmts = mt9m001_colour_fmts;
                break;
        case 0x8431:
                mt9m001->fmts = mt9m001_monochrome_fmts;
                break;
        default:
                dev_err(&client->dev,
                        "No MT9M001 chip detected, register read %x\n", data);
                ret = -ENODEV;
                goto done;
        }

        mt9m001->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)
                mt9m001->num_fmts++;
        else
                mt9m001->fmts++;

        if (flags & SOCAM_DATAWIDTH_8)
                mt9m001->num_fmts++;

        mt9m001->fmt = &mt9m001->fmts[0];

        dev_info(&client->dev, "Detected a MT9M001 chip ID %x (%s)\n", data,
                 data == 0x8431 ? "C12STM" : "C12ST");

        ret = mt9m001_init(client);
        if (ret < 0) {
                dev_err(&client->dev, "Failed to initialise the camera\n");
                goto done;
        }

        /* mt9m001_init() has reset the chip, returning registers to defaults */
        ret = v4l2_ctrl_handler_setup(&mt9m001->hdl);

done:
        mt9m001_s_power(&mt9m001->subdev, 0);
        return ret;
}

static void mt9m001_video_remove(struct soc_camera_subdev_desc *ssdd)
{
        if (ssdd->free_bus)
                ssdd->free_bus(ssdd);
}

static int mt9m001_g_skip_top_lines(struct v4l2_subdev *sd, u32 *lines)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct mt9m001 *mt9m001 = to_mt9m001(client);

        *lines = mt9m001->y_skip_top;

        return 0;
}

static const struct v4l2_ctrl_ops mt9m001_ctrl_ops = {
        .g_volatile_ctrl = mt9m001_g_volatile_ctrl,
        .s_ctrl = mt9m001_s_ctrl,
};

static struct v4l2_subdev_core_ops mt9m001_subdev_core_ops = {
#ifdef CONFIG_VIDEO_ADV_DEBUG
        .g_register     = mt9m001_g_register,
        .s_register     = mt9m001_s_register,
#endif
        .s_power        = mt9m001_s_power,
};

static int mt9m001_enum_fmt(struct v4l2_subdev *sd, unsigned int index,
                            u32 *code)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct mt9m001 *mt9m001 = to_mt9m001(client);

        if (index >= mt9m001->num_fmts)
                return -EINVAL;

        *code = mt9m001->fmts[index].code;
        return 0;
}

static int mt9m001_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);

        /* MT9M001 has all capture_format parameters fixed */
        cfg->flags = V4L2_MBUS_PCLK_SAMPLE_FALLING |
                V4L2_MBUS_HSYNC_ACTIVE_HIGH | V4L2_MBUS_VSYNC_ACTIVE_HIGH |
                V4L2_MBUS_DATA_ACTIVE_HIGH | V4L2_MBUS_MASTER;
        cfg->type = V4L2_MBUS_PARALLEL;
        cfg->flags = soc_camera_apply_board_flags(ssdd, cfg);

        return 0;
}

static int mt9m001_s_mbus_config(struct v4l2_subdev *sd,
                                const struct v4l2_mbus_config *cfg)
{
        const struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct soc_camera_subdev_desc *ssdd = soc_camera_i2c_to_desc(client);
        struct mt9m001 *mt9m001 = to_mt9m001(client);
        unsigned int bps = soc_mbus_get_fmtdesc(mt9m001->fmt->code)->bits_per_sample;

        if (ssdd->set_bus_param)
                return ssdd->set_bus_param(ssdd, 1 << (bps - 1));

        /*
         * Without board specific bus width settings we only support the
         * sensors native bus width
         */
        return bps == 10 ? 0 : -EINVAL;
}

static struct v4l2_subdev_video_ops mt9m001_subdev_video_ops = {
        .s_stream       = mt9m001_s_stream,
        .s_mbus_fmt     = mt9m001_s_fmt,
        .g_mbus_fmt     = mt9m001_g_fmt,
        .try_mbus_fmt   = mt9m001_try_fmt,
        .s_crop         = mt9m001_s_crop,
        .g_crop         = mt9m001_g_crop,
        .cropcap        = mt9m001_cropcap,
        .enum_mbus_fmt  = mt9m001_enum_fmt,
        .g_mbus_config  = mt9m001_g_mbus_config,
        .s_mbus_config  = mt9m001_s_mbus_config,
};

static struct v4l2_subdev_sensor_ops mt9m001_subdev_sensor_ops = {
        .g_skip_top_lines       = mt9m001_g_skip_top_lines,
};

static struct v4l2_subdev_ops mt9m001_subdev_ops = {
        .core   = &mt9m001_subdev_core_ops,
        .video  = &mt9m001_subdev_video_ops,
        .sensor = &mt9m001_subdev_sensor_ops,
};

static int mt9m001_probe(struct i2c_client *client,
                         const struct i2c_device_id *did)
{
        struct mt9m001 *mt9m001;
        struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
        struct soc_camera_subdev_desc *ssdd = soc_camera_i2c_to_desc(client);
        int ret;

        if (!ssdd) {
                dev_err(&client->dev, "MT9M001 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;
        }

        mt9m001 = devm_kzalloc(&client->dev, sizeof(struct mt9m001), GFP_KERNEL);
        if (!mt9m001)
                return -ENOMEM;

        v4l2_i2c_subdev_init(&mt9m001->subdev, client, &mt9m001_subdev_ops);
        v4l2_ctrl_handler_init(&mt9m001->hdl, 4);
        v4l2_ctrl_new_std(&mt9m001->hdl, &mt9m001_ctrl_ops,
                        V4L2_CID_VFLIP, 0, 1, 1, 0);
        v4l2_ctrl_new_std(&mt9m001->hdl, &mt9m001_ctrl_ops,
                        V4L2_CID_GAIN, 0, 127, 1, 64);
        mt9m001->exposure = v4l2_ctrl_new_std(&mt9m001->hdl, &mt9m001_ctrl_ops,
                        V4L2_CID_EXPOSURE, 1, 255, 1, 255);
        /*
         * Simulated autoexposure. If enabled, we calculate shutter width
         * ourselves in the driver based on vertical blanking and frame width
         */
        mt9m001->autoexposure = v4l2_ctrl_new_std_menu(&mt9m001->hdl,
                        &mt9m001_ctrl_ops, V4L2_CID_EXPOSURE_AUTO, 1, 0,
                        V4L2_EXPOSURE_AUTO);
        mt9m001->subdev.ctrl_handler = &mt9m001->hdl;
        if (mt9m001->hdl.error)
                return mt9m001->hdl.error;

        v4l2_ctrl_auto_cluster(2, &mt9m001->autoexposure,
                                        V4L2_EXPOSURE_MANUAL, true);

        /* Second stage probe - when a capture adapter is there */
        mt9m001->y_skip_top     = 0;
        mt9m001->rect.left      = MT9M001_COLUMN_SKIP;
        mt9m001->rect.top       = MT9M001_ROW_SKIP;
        mt9m001->rect.width     = MT9M001_MAX_WIDTH;
        mt9m001->rect.height    = MT9M001_MAX_HEIGHT;

        mt9m001->clk = v4l2_clk_get(&client->dev, "mclk");
        if (IS_ERR(mt9m001->clk)) {
                ret = PTR_ERR(mt9m001->clk);
                goto eclkget;
        }

        ret = mt9m001_video_probe(ssdd, client);
        if (ret) {
                v4l2_clk_put(mt9m001->clk);
eclkget:
                v4l2_ctrl_handler_free(&mt9m001->hdl);
        }

        return ret;
}

static int mt9m001_remove(struct i2c_client *client)
{
        struct mt9m001 *mt9m001 = to_mt9m001(client);
        struct soc_camera_subdev_desc *ssdd = soc_camera_i2c_to_desc(client);

        v4l2_clk_put(mt9m001->clk);
        v4l2_device_unregister_subdev(&mt9m001->subdev);
        v4l2_ctrl_handler_free(&mt9m001->hdl);
        mt9m001_video_remove(ssdd);

        return 0;
}

static const struct i2c_device_id mt9m001_id[] = {
        { "mt9m001", 0 },
        { }
};
MODULE_DEVICE_TABLE(i2c, mt9m001_id);

static struct i2c_driver mt9m001_i2c_driver = {
        .driver = {
                .name = "mt9m001",
        },
        .probe          = mt9m001_probe,
        .remove         = mt9m001_remove,
        .id_table       = mt9m001_id,
};

module_i2c_driver(mt9m001_i2c_driver);

MODULE_DESCRIPTION("Micron MT9M001 Camera driver");
MODULE_AUTHOR("Guennadi Liakhovetski <kernel@pengutronix.de>");
MODULE_LICENSE("GPL");