// SPDX-License-Identifier: GPL-2.0-only
/*
 * Sony imx334 sensor driver
 *
 * Copyright (C) 2021 Intel Corporation
 */
#include <asm/unaligned.h>

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>

#include <media/v4l2-ctrls.h>
#include <media/v4l2-fwnode.h>
#include <media/v4l2-subdev.h>

/* Streaming Mode */
#define IMX334_REG_MODE_SELECT  0x3000
#define IMX334_MODE_STANDBY     0x01
#define IMX334_MODE_STREAMING   0x00

/* Lines per frame */
#define IMX334_REG_LPFR         0x3030

/* Chip ID */
#define IMX334_REG_ID           0x3044
#define IMX334_ID               0x1e

/* Exposure control */
#define IMX334_REG_SHUTTER      0x3058
#define IMX334_EXPOSURE_MIN     1
#define IMX334_EXPOSURE_OFFSET  5
#define IMX334_EXPOSURE_STEP    1
#define IMX334_EXPOSURE_DEFAULT 0x0648

/* Analog gain control */
#define IMX334_REG_AGAIN        0x30e8
#define IMX334_AGAIN_MIN        0
#define IMX334_AGAIN_MAX        240
#define IMX334_AGAIN_STEP       1
#define IMX334_AGAIN_DEFAULT    0

/* Group hold register */
#define IMX334_REG_HOLD         0x3001

/* Input clock rate */
#define IMX334_INCLK_RATE       24000000

/* CSI2 HW configuration */
#define IMX334_LINK_FREQ        891000000
#define IMX334_NUM_DATA_LANES   4

#define IMX334_REG_MIN          0x00
#define IMX334_REG_MAX          0xfffff

/**
 * struct imx334_reg - imx334 sensor register
 * @address: Register address
 * @val: Register value
 */
struct imx334_reg {
        u16 address;
        u8 val;
};

/**
 * struct imx334_reg_list - imx334 sensor register list
 * @num_of_regs: Number of registers in the list
 * @regs: Pointer to register list
 */
struct imx334_reg_list {
        u32 num_of_regs;
        const struct imx334_reg *regs;
};

/**
 * struct imx334_mode - imx334 sensor mode structure
 * @width: Frame width
 * @height: Frame height
 * @code: Format code
 * @hblank: Horizontal blanking in lines
 * @vblank: Vertical blanking in lines
 * @vblank_min: Minimal vertical blanking in lines
 * @vblank_max: Maximum vertical blanking in lines
 * @pclk: Sensor pixel clock
 * @link_freq_idx: Link frequency index
 * @reg_list: Register list for sensor mode
 */
struct imx334_mode {
        u32 width;
        u32 height;
        u32 code;
        u32 hblank;
        u32 vblank;
        u32 vblank_min;
        u32 vblank_max;
        u64 pclk;
        u32 link_freq_idx;
        struct imx334_reg_list reg_list;
};

/**
 * struct imx334 - imx334 sensor device structure
 * @dev: Pointer to generic device
 * @client: Pointer to i2c client
 * @sd: V4L2 sub-device
 * @pad: Media pad. Only one pad supported
 * @reset_gpio: Sensor reset gpio
 * @inclk: Sensor input clock
 * @ctrl_handler: V4L2 control handler
 * @link_freq_ctrl: Pointer to link frequency control
 * @pclk_ctrl: Pointer to pixel clock control
 * @hblank_ctrl: Pointer to horizontal blanking control
 * @vblank_ctrl: Pointer to vertical blanking control
 * @exp_ctrl: Pointer to exposure control
 * @again_ctrl: Pointer to analog gain control
 * @vblank: Vertical blanking in lines
 * @cur_mode: Pointer to current selected sensor mode
 * @mutex: Mutex for serializing sensor controls
 * @streaming: Flag indicating streaming state
 */
struct imx334 {
        struct device *dev;
        struct i2c_client *client;
        struct v4l2_subdev sd;
        struct media_pad pad;
        struct gpio_desc *reset_gpio;
        struct clk *inclk;
        struct v4l2_ctrl_handler ctrl_handler;
        struct v4l2_ctrl *link_freq_ctrl;
        struct v4l2_ctrl *pclk_ctrl;
        struct v4l2_ctrl *hblank_ctrl;
        struct v4l2_ctrl *vblank_ctrl;
        struct {
                struct v4l2_ctrl *exp_ctrl;
                struct v4l2_ctrl *again_ctrl;
        };
        u32 vblank;
        const struct imx334_mode *cur_mode;
        struct mutex mutex;
        bool streaming;
};

static const s64 link_freq[] = {
        IMX334_LINK_FREQ,
};

/* Sensor mode registers */
static const struct imx334_reg mode_3840x2160_regs[] = {
        {0x3000, 0x01},
        {0x3002, 0x00},
        {0x3018, 0x04},
        {0x37b0, 0x36},
        {0x304c, 0x00},
        {0x300c, 0x3b},
        {0x300d, 0x2a},
        {0x3034, 0x26},
        {0x3035, 0x02},
        {0x314c, 0x29},
        {0x314d, 0x01},
        {0x315a, 0x02},
        {0x3168, 0xa0},
        {0x316a, 0x7e},
        {0x3288, 0x21},
        {0x328a, 0x02},
        {0x302c, 0x3c},
        {0x302e, 0x00},
        {0x302f, 0x0f},
        {0x3076, 0x70},
        {0x3077, 0x08},
        {0x3090, 0x70},
        {0x3091, 0x08},
        {0x30d8, 0x20},
        {0x30d9, 0x12},
        {0x3308, 0x70},
        {0x3309, 0x08},
        {0x3414, 0x05},
        {0x3416, 0x18},
        {0x35ac, 0x0e},
        {0x3648, 0x01},
        {0x364a, 0x04},
        {0x364c, 0x04},
        {0x3678, 0x01},
        {0x367c, 0x31},
        {0x367e, 0x31},
        {0x3708, 0x02},
        {0x3714, 0x01},
        {0x3715, 0x02},
        {0x3716, 0x02},
        {0x3717, 0x02},
        {0x371c, 0x3d},
        {0x371d, 0x3f},
        {0x372c, 0x00},
        {0x372d, 0x00},
        {0x372e, 0x46},
        {0x372f, 0x00},
        {0x3730, 0x89},
        {0x3731, 0x00},
        {0x3732, 0x08},
        {0x3733, 0x01},
        {0x3734, 0xfe},
        {0x3735, 0x05},
        {0x375d, 0x00},
        {0x375e, 0x00},
        {0x375f, 0x61},
        {0x3760, 0x06},
        {0x3768, 0x1b},
        {0x3769, 0x1b},
        {0x376a, 0x1a},
        {0x376b, 0x19},
        {0x376c, 0x18},
        {0x376d, 0x14},
        {0x376e, 0x0f},
        {0x3776, 0x00},
        {0x3777, 0x00},
        {0x3778, 0x46},
        {0x3779, 0x00},
        {0x377a, 0x08},
        {0x377b, 0x01},
        {0x377c, 0x45},
        {0x377d, 0x01},
        {0x377e, 0x23},
        {0x377f, 0x02},
        {0x3780, 0xd9},
        {0x3781, 0x03},
        {0x3782, 0xf5},
        {0x3783, 0x06},
        {0x3784, 0xa5},
        {0x3788, 0x0f},
        {0x378a, 0xd9},
        {0x378b, 0x03},
        {0x378c, 0xeb},
        {0x378d, 0x05},
        {0x378e, 0x87},
        {0x378f, 0x06},
        {0x3790, 0xf5},
        {0x3792, 0x43},
        {0x3794, 0x7a},
        {0x3796, 0xa1},
        {0x3e04, 0x0e},
        {0x3a00, 0x01},
};

/* Supported sensor mode configurations */
static const struct imx334_mode supported_mode = {
        .width = 3840,
        .height = 2160,
        .hblank = 560,
        .vblank = 2340,
        .vblank_min = 90,
        .vblank_max = 132840,
        .pclk = 594000000,
        .link_freq_idx = 0,
        .code = MEDIA_BUS_FMT_SRGGB12_1X12,
        .reg_list = {
                .num_of_regs = ARRAY_SIZE(mode_3840x2160_regs),
                .regs = mode_3840x2160_regs,
        },
};

/**
 * to_imx334() - imv334 V4L2 sub-device to imx334 device.
 * @subdev: pointer to imx334 V4L2 sub-device
 *
 * Return: pointer to imx334 device
 */
static inline struct imx334 *to_imx334(struct v4l2_subdev *subdev)
{
        return container_of(subdev, struct imx334, sd);
}

/**
 * imx334_read_reg() - Read registers.
 * @imx334: pointer to imx334 device
 * @reg: register address
 * @len: length of bytes to read. Max supported bytes is 4
 * @val: pointer to register value to be filled.
 *
 * Big endian register addresses with little endian values.
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_read_reg(struct imx334 *imx334, u16 reg, u32 len, u32 *val)
{
        struct i2c_client *client = v4l2_get_subdevdata(&imx334->sd);
        struct i2c_msg msgs[2] = {0};
        u8 addr_buf[2] = {0};
        u8 data_buf[4] = {0};
        int ret;

        if (WARN_ON(len > 4))
                return -EINVAL;

        put_unaligned_be16(reg, addr_buf);

        /* Write register address */
        msgs[0].addr = client->addr;
        msgs[0].flags = 0;
        msgs[0].len = ARRAY_SIZE(addr_buf);
        msgs[0].buf = addr_buf;

        /* Read data from register */
        msgs[1].addr = client->addr;
        msgs[1].flags = I2C_M_RD;
        msgs[1].len = len;
        msgs[1].buf = data_buf;

        ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
        if (ret != ARRAY_SIZE(msgs))
                return -EIO;

        *val = get_unaligned_le32(data_buf);

        return 0;
}

/**
 * imx334_write_reg() - Write register
 * @imx334: pointer to imx334 device
 * @reg: register address
 * @len: length of bytes. Max supported bytes is 4
 * @val: register value
 *
 * Big endian register addresses with little endian values.
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_write_reg(struct imx334 *imx334, u16 reg, u32 len, u32 val)
{
        struct i2c_client *client = v4l2_get_subdevdata(&imx334->sd);
        u8 buf[6] = {0};

        if (WARN_ON(len > 4))
                return -EINVAL;

        put_unaligned_be16(reg, buf);
        put_unaligned_le32(val, buf + 2);
        if (i2c_master_send(client, buf, len + 2) != len + 2)
                return -EIO;

        return 0;
}

/**
 * imx334_write_regs() - Write a list of registers
 * @imx334: pointer to imx334 device
 * @regs: list of registers to be written
 * @len: length of registers array
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_write_regs(struct imx334 *imx334,
                             const struct imx334_reg *regs, u32 len)
{
        unsigned int i;
        int ret;

        for (i = 0; i < len; i++) {
                ret = imx334_write_reg(imx334, regs[i].address, 1, regs[i].val);
                if (ret)
                        return ret;
        }

        return 0;
}

/**
 * imx334_update_controls() - Update control ranges based on streaming mode
 * @imx334: pointer to imx334 device
 * @mode: pointer to imx334_mode sensor mode
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_update_controls(struct imx334 *imx334,
                                  const struct imx334_mode *mode)
{
        int ret;

        ret = __v4l2_ctrl_s_ctrl(imx334->link_freq_ctrl, mode->link_freq_idx);
        if (ret)
                return ret;

        ret = __v4l2_ctrl_s_ctrl(imx334->hblank_ctrl, mode->hblank);
        if (ret)
                return ret;

        return __v4l2_ctrl_modify_range(imx334->vblank_ctrl, mode->vblank_min,
                                        mode->vblank_max, 1, mode->vblank);
}

/**
 * imx334_update_exp_gain() - Set updated exposure and gain
 * @imx334: pointer to imx334 device
 * @exposure: updated exposure value
 * @gain: updated analog gain value
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_update_exp_gain(struct imx334 *imx334, u32 exposure, u32 gain)
{
        u32 lpfr, shutter;
        int ret;

        lpfr = imx334->vblank + imx334->cur_mode->height;
        shutter = lpfr - exposure;

        dev_dbg(imx334->dev, "Set long exp %u analog gain %u sh0 %u lpfr %u",
                exposure, gain, shutter, lpfr);

        ret = imx334_write_reg(imx334, IMX334_REG_HOLD, 1, 1);
        if (ret)
                return ret;

        ret = imx334_write_reg(imx334, IMX334_REG_LPFR, 3, lpfr);
        if (ret)
                goto error_release_group_hold;

        ret = imx334_write_reg(imx334, IMX334_REG_SHUTTER, 3, shutter);
        if (ret)
                goto error_release_group_hold;

        ret = imx334_write_reg(imx334, IMX334_REG_AGAIN, 1, gain);

error_release_group_hold:
        imx334_write_reg(imx334, IMX334_REG_HOLD, 1, 0);

        return ret;
}

/**
 * imx334_set_ctrl() - Set subdevice control
 * @ctrl: pointer to v4l2_ctrl structure
 *
 * Supported controls:
 * - V4L2_CID_VBLANK
 * - cluster controls:
 *   - V4L2_CID_ANALOGUE_GAIN
 *   - V4L2_CID_EXPOSURE
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_set_ctrl(struct v4l2_ctrl *ctrl)
{
        struct imx334 *imx334 =
                container_of(ctrl->handler, struct imx334, ctrl_handler);
        u32 analog_gain;
        u32 exposure;
        int ret;

        switch (ctrl->id) {
        case V4L2_CID_VBLANK:
                imx334->vblank = imx334->vblank_ctrl->val;

                dev_dbg(imx334->dev, "Received vblank %u, new lpfr %u",
                        imx334->vblank,
                        imx334->vblank + imx334->cur_mode->height);

                ret = __v4l2_ctrl_modify_range(imx334->exp_ctrl,
                                               IMX334_EXPOSURE_MIN,
                                               imx334->vblank +
                                               imx334->cur_mode->height -
                                               IMX334_EXPOSURE_OFFSET,
                                               1, IMX334_EXPOSURE_DEFAULT);
                break;
        case V4L2_CID_EXPOSURE:

                /* Set controls only if sensor is in power on state */
                if (!pm_runtime_get_if_in_use(imx334->dev))
                        return 0;

                exposure = ctrl->val;
                analog_gain = imx334->again_ctrl->val;

                dev_dbg(imx334->dev, "Received exp %u analog gain %u",
                        exposure, analog_gain);

                ret = imx334_update_exp_gain(imx334, exposure, analog_gain);

                pm_runtime_put(imx334->dev);

                break;
        default:
                dev_err(imx334->dev, "Invalid control %d", ctrl->id);
                ret = -EINVAL;
        }

        return ret;
}

/* V4l2 subdevice control ops*/
static const struct v4l2_ctrl_ops imx334_ctrl_ops = {
        .s_ctrl = imx334_set_ctrl,
};

/**
 * imx334_enum_mbus_code() - Enumerate V4L2 sub-device mbus codes
 * @sd: pointer to imx334 V4L2 sub-device structure
 * @cfg: V4L2 sub-device pad configuration
 * @code: V4L2 sub-device code enumeration need to be filled
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_enum_mbus_code(struct v4l2_subdev *sd,
                                 struct v4l2_subdev_pad_config *cfg,
                                 struct v4l2_subdev_mbus_code_enum *code)
{
        if (code->index > 0)
                return -EINVAL;

        code->code = supported_mode.code;

        return 0;
}

/**
 * imx334_enum_frame_size() - Enumerate V4L2 sub-device frame sizes
 * @sd: pointer to imx334 V4L2 sub-device structure
 * @cfg: V4L2 sub-device pad configuration
 * @fsize: V4L2 sub-device size enumeration need to be filled
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_enum_frame_size(struct v4l2_subdev *sd,
                                  struct v4l2_subdev_pad_config *cfg,
                                  struct v4l2_subdev_frame_size_enum *fsize)
{
        if (fsize->index > 0)
                return -EINVAL;

        if (fsize->code != supported_mode.code)
                return -EINVAL;

        fsize->min_width = supported_mode.width;
        fsize->max_width = fsize->min_width;
        fsize->min_height = supported_mode.height;
        fsize->max_height = fsize->min_height;

        return 0;
}

/**
 * imx334_fill_pad_format() - Fill subdevice pad format
 *                            from selected sensor mode
 * @imx334: pointer to imx334 device
 * @mode: pointer to imx334_mode sensor mode
 * @fmt: V4L2 sub-device format need to be filled
 */
static void imx334_fill_pad_format(struct imx334 *imx334,
                                   const struct imx334_mode *mode,
                                   struct v4l2_subdev_format *fmt)
{
        fmt->format.width = mode->width;
        fmt->format.height = mode->height;
        fmt->format.code = mode->code;
        fmt->format.field = V4L2_FIELD_NONE;
        fmt->format.colorspace = V4L2_COLORSPACE_RAW;
        fmt->format.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
        fmt->format.quantization = V4L2_QUANTIZATION_DEFAULT;
        fmt->format.xfer_func = V4L2_XFER_FUNC_NONE;
}

/**
 * imx334_get_pad_format() - Get subdevice pad format
 * @sd: pointer to imx334 V4L2 sub-device structure
 * @cfg: V4L2 sub-device pad configuration
 * @fmt: V4L2 sub-device format need to be set
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_get_pad_format(struct v4l2_subdev *sd,
                                 struct v4l2_subdev_pad_config *cfg,
                                 struct v4l2_subdev_format *fmt)
{
        struct imx334 *imx334 = to_imx334(sd);

        mutex_lock(&imx334->mutex);

        if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
                struct v4l2_mbus_framefmt *framefmt;

                framefmt = v4l2_subdev_get_try_format(sd, cfg, fmt->pad);
                fmt->format = *framefmt;
        } else {
                imx334_fill_pad_format(imx334, imx334->cur_mode, fmt);
        }

        mutex_unlock(&imx334->mutex);

        return 0;
}

/**
 * imx334_set_pad_format() - Set subdevice pad format
 * @sd: pointer to imx334 V4L2 sub-device structure
 * @cfg: V4L2 sub-device pad configuration
 * @fmt: V4L2 sub-device format need to be set
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_set_pad_format(struct v4l2_subdev *sd,
                                 struct v4l2_subdev_pad_config *cfg,
                                 struct v4l2_subdev_format *fmt)
{
        struct imx334 *imx334 = to_imx334(sd);
        const struct imx334_mode *mode;
        int ret = 0;

        mutex_lock(&imx334->mutex);

        mode = &supported_mode;
        imx334_fill_pad_format(imx334, mode, fmt);

        if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
                struct v4l2_mbus_framefmt *framefmt;

                framefmt = v4l2_subdev_get_try_format(sd, cfg, fmt->pad);
                *framefmt = fmt->format;
        } else {
                ret = imx334_update_controls(imx334, mode);
                if (!ret)
                        imx334->cur_mode = mode;
        }

        mutex_unlock(&imx334->mutex);

        return ret;
}

/**
 * imx334_init_pad_cfg() - Initialize sub-device pad configuration
 * @sd: pointer to imx334 V4L2 sub-device structure
 * @cfg: V4L2 sub-device pad configuration
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_init_pad_cfg(struct v4l2_subdev *sd,
                               struct v4l2_subdev_pad_config *cfg)
{
        struct imx334 *imx334 = to_imx334(sd);
        struct v4l2_subdev_format fmt = { 0 };

        fmt.which = cfg ? V4L2_SUBDEV_FORMAT_TRY : V4L2_SUBDEV_FORMAT_ACTIVE;
        imx334_fill_pad_format(imx334, &supported_mode, &fmt);

        return imx334_set_pad_format(sd, cfg, &fmt);
}

/**
 * imx334_start_streaming() - Start sensor stream
 * @imx334: pointer to imx334 device
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_start_streaming(struct imx334 *imx334)
{
        const struct imx334_reg_list *reg_list;
        int ret;

        /* Write sensor mode registers */
        reg_list = &imx334->cur_mode->reg_list;
        ret = imx334_write_regs(imx334, reg_list->regs,
                                reg_list->num_of_regs);
        if (ret) {
                dev_err(imx334->dev, "fail to write initial registers");
                return ret;
        }

        /* Setup handler will write actual exposure and gain */
        ret =  __v4l2_ctrl_handler_setup(imx334->sd.ctrl_handler);
        if (ret) {
                dev_err(imx334->dev, "fail to setup handler");
                return ret;
        }

        /* Start streaming */
        ret = imx334_write_reg(imx334, IMX334_REG_MODE_SELECT,
                               1, IMX334_MODE_STREAMING);
        if (ret) {
                dev_err(imx334->dev, "fail to start streaming");
                return ret;
        }

        return 0;
}

/**
 * imx334_stop_streaming() - Stop sensor stream
 * @imx334: pointer to imx334 device
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_stop_streaming(struct imx334 *imx334)
{
        return imx334_write_reg(imx334, IMX334_REG_MODE_SELECT,
                                1, IMX334_MODE_STANDBY);
}

/**
 * imx334_set_stream() - Enable sensor streaming
 * @sd: pointer to imx334 subdevice
 * @enable: set to enable sensor streaming
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_set_stream(struct v4l2_subdev *sd, int enable)
{
        struct imx334 *imx334 = to_imx334(sd);
        int ret;

        mutex_lock(&imx334->mutex);

        if (imx334->streaming == enable) {
                mutex_unlock(&imx334->mutex);
                return 0;
        }

        if (enable) {
                ret = pm_runtime_get_sync(imx334->dev);
                if (ret)
                        goto error_power_off;

                ret = imx334_start_streaming(imx334);
                if (ret)
                        goto error_power_off;
        } else {
                imx334_stop_streaming(imx334);
                pm_runtime_put(imx334->dev);
        }

        imx334->streaming = enable;

        mutex_unlock(&imx334->mutex);

        return 0;

error_power_off:
        pm_runtime_put(imx334->dev);
        mutex_unlock(&imx334->mutex);

        return ret;
}

/**
 * imx334_detect() - Detect imx334 sensor
 * @imx334: pointer to imx334 device
 *
 * Return: 0 if successful, -EIO if sensor id does not match
 */
static int imx334_detect(struct imx334 *imx334)
{
        int ret;
        u32 val;

        ret = imx334_read_reg(imx334, IMX334_REG_ID, 2, &val);
        if (ret)
                return ret;

        if (val != IMX334_ID) {
                dev_err(imx334->dev, "chip id mismatch: %x!=%x",
                        IMX334_ID, val);
                return -ENXIO;
        }

        return 0;
}

/**
 * imx334_parse_hw_config() - Parse HW configuration and check if supported
 * @imx334: pointer to imx334 device
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_parse_hw_config(struct imx334 *imx334)
{
        struct fwnode_handle *fwnode = dev_fwnode(imx334->dev);
        struct v4l2_fwnode_endpoint bus_cfg = {
                .bus_type = V4L2_MBUS_CSI2_DPHY
        };
        struct fwnode_handle *ep;
        unsigned long rate;
        int ret;
        int i;

        if (!fwnode)
                return -ENXIO;

        /* Request optional reset pin */
        imx334->reset_gpio = devm_gpiod_get_optional(imx334->dev, "reset",
                                                     GPIOD_OUT_LOW);
        if (IS_ERR(imx334->reset_gpio)) {
                dev_err(imx334->dev, "failed to get reset gpio %ld",
                        PTR_ERR(imx334->reset_gpio));
                return PTR_ERR(imx334->reset_gpio);
        }

        /* Get sensor input clock */
        imx334->inclk = devm_clk_get(imx334->dev, NULL);
        if (IS_ERR(imx334->inclk)) {
                dev_err(imx334->dev, "could not get inclk");
                return PTR_ERR(imx334->inclk);
        }

        rate = clk_get_rate(imx334->inclk);
        if (rate != IMX334_INCLK_RATE) {
                dev_err(imx334->dev, "inclk frequency mismatch");
                return -EINVAL;
        }

        ep = fwnode_graph_get_next_endpoint(fwnode, NULL);
        if (!ep)
                return -ENXIO;

        ret = v4l2_fwnode_endpoint_alloc_parse(ep, &bus_cfg);
        fwnode_handle_put(ep);
        if (ret)
                return ret;

        if (bus_cfg.bus.mipi_csi2.num_data_lanes != IMX334_NUM_DATA_LANES) {
                dev_err(imx334->dev,
                        "number of CSI2 data lanes %d is not supported",
                        bus_cfg.bus.mipi_csi2.num_data_lanes);
                ret = -EINVAL;
                goto done_endpoint_free;
        }

        if (!bus_cfg.nr_of_link_frequencies) {
                dev_err(imx334->dev, "no link frequencies defined");
                ret = -EINVAL;
                goto done_endpoint_free;
        }

        for (i = 0; i < bus_cfg.nr_of_link_frequencies; i++)
                if (bus_cfg.link_frequencies[i] == IMX334_LINK_FREQ)
                        goto done_endpoint_free;

        ret = -EINVAL;

done_endpoint_free:
        v4l2_fwnode_endpoint_free(&bus_cfg);

        return ret;
}

/* V4l2 subdevice ops */
static const struct v4l2_subdev_video_ops imx334_video_ops = {
        .s_stream = imx334_set_stream,
};

static const struct v4l2_subdev_pad_ops imx334_pad_ops = {
        .init_cfg = imx334_init_pad_cfg,
        .enum_mbus_code = imx334_enum_mbus_code,
        .enum_frame_size = imx334_enum_frame_size,
        .get_fmt = imx334_get_pad_format,
        .set_fmt = imx334_set_pad_format,
};

static const struct v4l2_subdev_ops imx334_subdev_ops = {
        .video = &imx334_video_ops,
        .pad = &imx334_pad_ops,
};

/**
 * imx334_power_on() - Sensor power on sequence
 * @dev: pointer to i2c device
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_power_on(struct device *dev)
{
        struct v4l2_subdev *sd = dev_get_drvdata(dev);
        struct imx334 *imx334 = to_imx334(sd);
        int ret;

        gpiod_set_value_cansleep(imx334->reset_gpio, 1);

        ret = clk_prepare_enable(imx334->inclk);
        if (ret) {
                dev_err(imx334->dev, "fail to enable inclk");
                goto error_reset;
        }

        usleep_range(18000, 20000);

        return 0;

error_reset:
        gpiod_set_value_cansleep(imx334->reset_gpio, 0);

        return ret;
}

/**
 * imx334_power_off() - Sensor power off sequence
 * @dev: pointer to i2c device
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_power_off(struct device *dev)
{
        struct v4l2_subdev *sd = dev_get_drvdata(dev);
        struct imx334 *imx334 = to_imx334(sd);

        gpiod_set_value_cansleep(imx334->reset_gpio, 0);

        clk_disable_unprepare(imx334->inclk);

        return 0;
}

/**
 * imx334_init_controls() - Initialize sensor subdevice controls
 * @imx334: pointer to imx334 device
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_init_controls(struct imx334 *imx334)
{
        struct v4l2_ctrl_handler *ctrl_hdlr = &imx334->ctrl_handler;
        const struct imx334_mode *mode = imx334->cur_mode;
        u32 lpfr;
        int ret;

        ret = v4l2_ctrl_handler_init(ctrl_hdlr, 6);
        if (ret)
                return ret;

        /* Serialize controls with sensor device */
        ctrl_hdlr->lock = &imx334->mutex;

        /* Initialize exposure and gain */
        lpfr = mode->vblank + mode->height;
        imx334->exp_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
                                             &imx334_ctrl_ops,
                                             V4L2_CID_EXPOSURE,
                                             IMX334_EXPOSURE_MIN,
                                             lpfr - IMX334_EXPOSURE_OFFSET,
                                             IMX334_EXPOSURE_STEP,
                                             IMX334_EXPOSURE_DEFAULT);

        imx334->again_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
                                               &imx334_ctrl_ops,
                                               V4L2_CID_ANALOGUE_GAIN,
                                               IMX334_AGAIN_MIN,
                                               IMX334_AGAIN_MAX,
                                               IMX334_AGAIN_STEP,
                                               IMX334_AGAIN_DEFAULT);

        v4l2_ctrl_cluster(2, &imx334->exp_ctrl);

        imx334->vblank_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
                                                &imx334_ctrl_ops,
                                                V4L2_CID_VBLANK,
                                                mode->vblank_min,
                                                mode->vblank_max,
                                                1, mode->vblank);

        /* Read only controls */
        imx334->pclk_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
                                              &imx334_ctrl_ops,
                                              V4L2_CID_PIXEL_RATE,
                                              mode->pclk, mode->pclk,
                                              1, mode->pclk);

        imx334->link_freq_ctrl = v4l2_ctrl_new_int_menu(ctrl_hdlr,
                                                        &imx334_ctrl_ops,
                                                        V4L2_CID_LINK_FREQ,
                                                        ARRAY_SIZE(link_freq) -
                                                        1,
                                                        mode->link_freq_idx,
                                                        link_freq);
        if (imx334->link_freq_ctrl)
                imx334->link_freq_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;

        imx334->hblank_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
                                                &imx334_ctrl_ops,
                                                V4L2_CID_HBLANK,
                                                IMX334_REG_MIN,
                                                IMX334_REG_MAX,
                                                1, mode->hblank);
        if (imx334->hblank_ctrl)
                imx334->hblank_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;

        if (ctrl_hdlr->error) {
                dev_err(imx334->dev, "control init failed: %d",
                        ctrl_hdlr->error);
                v4l2_ctrl_handler_free(ctrl_hdlr);
                return ctrl_hdlr->error;
        }

        imx334->sd.ctrl_handler = ctrl_hdlr;

        return 0;
}

/**
 * imx334_probe() - I2C client device binding
 * @client: pointer to i2c client device
 *

 * Return: 0 if successful, error code otherwise.
 */
static int imx334_probe(struct i2c_client *client)
{
        struct imx334 *imx334;
        int ret;

        imx334 = devm_kzalloc(&client->dev, sizeof(*imx334), GFP_KERNEL);
        if (!imx334)
                return -ENOMEM;

        imx334->dev = &client->dev;

        /* Initialize subdev */
        v4l2_i2c_subdev_init(&imx334->sd, client, &imx334_subdev_ops);

        ret = imx334_parse_hw_config(imx334);
        if (ret) {
                dev_err(imx334->dev, "HW configuration is not supported");
                return ret;
        }

        mutex_init(&imx334->mutex);

        ret = imx334_power_on(imx334->dev);
        if (ret) {
                dev_err(imx334->dev, "failed to power-on the sensor");
                goto error_mutex_destroy;
        }

        /* Check module identity */
        ret = imx334_detect(imx334);
        if (ret) {
                dev_err(imx334->dev, "failed to find sensor: %d", ret);
                goto error_power_off;
        }

        /* Set default mode to max resolution */
        imx334->cur_mode = &supported_mode;
        imx334->vblank = imx334->cur_mode->vblank;

        ret = imx334_init_controls(imx334);
        if (ret) {
                dev_err(imx334->dev, "failed to init controls: %d", ret);
                goto error_power_off;
        }

        /* Initialize subdev */
        imx334->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
        imx334->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;

        /* Initialize source pad */
        imx334->pad.flags = MEDIA_PAD_FL_SOURCE;
        ret = media_entity_pads_init(&imx334->sd.entity, 1, &imx334->pad);
        if (ret) {
                dev_err(imx334->dev, "failed to init entity pads: %d", ret);
                goto error_handler_free;
        }

        ret = v4l2_async_register_subdev_sensor(&imx334->sd);
        if (ret < 0) {
                dev_err(imx334->dev,
                        "failed to register async subdev: %d", ret);
                goto error_media_entity;
        }

        pm_runtime_set_active(imx334->dev);
        pm_runtime_enable(imx334->dev);
        pm_runtime_idle(imx334->dev);

        return 0;

error_media_entity:
        media_entity_cleanup(&imx334->sd.entity);
error_handler_free:
        v4l2_ctrl_handler_free(imx334->sd.ctrl_handler);
error_power_off:
        imx334_power_off(imx334->dev);
error_mutex_destroy:
        mutex_destroy(&imx334->mutex);

        return ret;
}

/**
 * imx334_remove() - I2C client device unbinding
 * @client: pointer to I2C client device
 *
 * Return: 0 if successful, error code otherwise.
 */
static int imx334_remove(struct i2c_client *client)
{
        struct v4l2_subdev *sd = i2c_get_clientdata(client);
        struct imx334 *imx334 = to_imx334(sd);

        v4l2_async_unregister_subdev(sd);
        media_entity_cleanup(&sd->entity);
        v4l2_ctrl_handler_free(sd->ctrl_handler);

        pm_runtime_disable(&client->dev);
        pm_runtime_suspended(&client->dev);

        mutex_destroy(&imx334->mutex);

        return 0;
}

static const struct dev_pm_ops imx334_pm_ops = {
        SET_RUNTIME_PM_OPS(imx334_power_off, imx334_power_on, NULL)
};

static const struct of_device_id imx334_of_match[] = {
        { .compatible = "sony,imx334" },
        { }
};

MODULE_DEVICE_TABLE(of, imx334_of_match);

static struct i2c_driver imx334_driver = {
        .probe_new = imx334_probe,
        .remove = imx334_remove,
        .driver = {
                .name = "imx334",
                .pm = &imx334_pm_ops,
                .of_match_table = imx334_of_match,
        },
};

module_i2c_driver(imx334_driver);

MODULE_DESCRIPTION("Sony imx334 sensor driver");
MODULE_LICENSE("GPL");