// SPDX-License-Identifier: GPL-2.0-only
/*
 * OmniVision ov9282 Camera 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 OV9282_REG_MODE_SELECT  0x0100
#define OV9282_MODE_STANDBY     0x00
#define OV9282_MODE_STREAMING   0x01

/* Lines per frame */
#define OV9282_REG_LPFR         0x380e

/* Chip ID */
#define OV9282_REG_ID           0x300a
#define OV9282_ID               0x9281

/* Exposure control */
#define OV9282_REG_EXPOSURE     0x3500
#define OV9282_EXPOSURE_MIN     1
#define OV9282_EXPOSURE_OFFSET  12
#define OV9282_EXPOSURE_STEP    1
#define OV9282_EXPOSURE_DEFAULT 0x0282

/* Analog gain control */
#define OV9282_REG_AGAIN        0x3509
#define OV9282_AGAIN_MIN        0x10
#define OV9282_AGAIN_MAX        0xff
#define OV9282_AGAIN_STEP       1
#define OV9282_AGAIN_DEFAULT    0x10

/* Group hold register */
#define OV9282_REG_HOLD         0x3308

/* Input clock rate */
#define OV9282_INCLK_RATE       24000000

/* CSI2 HW configuration */
#define OV9282_LINK_FREQ        400000000
#define OV9282_NUM_DATA_LANES   2

#define OV9282_REG_MIN          0x00
#define OV9282_REG_MAX          0xfffff

/**
 * struct ov9282_reg - ov9282 sensor register
 * @address: Register address
 * @val: Register value
 */
struct ov9282_reg {
        u16 address;
        u8 val;
};

/**
 * struct ov9282_reg_list - ov9282 sensor register list
 * @num_of_regs: Number of registers in the list
 * @regs: Pointer to register list
 */
struct ov9282_reg_list {
        u32 num_of_regs;
        const struct ov9282_reg *regs;
};

/**
 * struct ov9282_mode - ov9282 sensor mode structure
 * @width: Frame width
 * @height: Frame height
 * @code: Format code
 * @hblank: Horizontal blanking in lines
 * @vblank: Vertical blanking in lines
 * @vblank_min: Minimum 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 ov9282_mode {
        u32 width;
        u32 height;
        u32 code;
        u32 hblank;
        u32 vblank;
        u32 vblank_min;
        u32 vblank_max;
        u64 pclk;
        u32 link_freq_idx;
        struct ov9282_reg_list reg_list;
};

/**
 * struct ov9282 - ov9282 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 ov9282 {
        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 ov9282_mode *cur_mode;
        struct mutex mutex;
        bool streaming;
};

static const s64 link_freq[] = {
        OV9282_LINK_FREQ,
};

/* Sensor mode registers */
static const struct ov9282_reg mode_1280x720_regs[] = {
        {0x0302, 0x32},
        {0x030d, 0x50},
        {0x030e, 0x02},
        {0x3001, 0x00},
        {0x3004, 0x00},
        {0x3005, 0x00},
        {0x3006, 0x04},
        {0x3011, 0x0a},
        {0x3013, 0x18},
        {0x301c, 0xf0},
        {0x3022, 0x01},
        {0x3030, 0x10},
        {0x3039, 0x32},
        {0x303a, 0x00},
        {0x3500, 0x00},
        {0x3501, 0x5f},
        {0x3502, 0x1e},
        {0x3503, 0x08},
        {0x3505, 0x8c},
        {0x3507, 0x03},
        {0x3508, 0x00},
        {0x3509, 0x10},
        {0x3610, 0x80},
        {0x3611, 0xa0},
        {0x3620, 0x6e},
        {0x3632, 0x56},
        {0x3633, 0x78},
        {0x3666, 0x00},
        {0x366f, 0x5a},
        {0x3680, 0x84},
        {0x3712, 0x80},
        {0x372d, 0x22},
        {0x3731, 0x80},
        {0x3732, 0x30},
        {0x3778, 0x00},
        {0x377d, 0x22},
        {0x3788, 0x02},
        {0x3789, 0xa4},
        {0x378a, 0x00},
        {0x378b, 0x4a},
        {0x3799, 0x20},
        {0x3800, 0x00},
        {0x3801, 0x00},
        {0x3802, 0x00},
        {0x3803, 0x00},
        {0x3804, 0x05},
        {0x3805, 0x0f},
        {0x3806, 0x02},
        {0x3807, 0xdf},
        {0x3808, 0x05},
        {0x3809, 0x00},
        {0x380a, 0x02},
        {0x380b, 0xd0},
        {0x380c, 0x05},
        {0x380d, 0xfa},
        {0x380e, 0x06},
        {0x380f, 0xce},
        {0x3810, 0x00},
        {0x3811, 0x08},
        {0x3812, 0x00},
        {0x3813, 0x08},
        {0x3814, 0x11},
        {0x3815, 0x11},
        {0x3820, 0x3c},
        {0x3821, 0x84},
        {0x3881, 0x42},
        {0x38a8, 0x02},
        {0x38a9, 0x80},
        {0x38b1, 0x00},
        {0x38c4, 0x00},
        {0x38c5, 0xc0},
        {0x38c6, 0x04},
        {0x38c7, 0x80},
        {0x3920, 0xff},
        {0x4003, 0x40},
        {0x4008, 0x02},
        {0x4009, 0x05},
        {0x400c, 0x00},
        {0x400d, 0x03},
        {0x4010, 0x40},
        {0x4043, 0x40},
        {0x4307, 0x30},
        {0x4317, 0x00},
        {0x4501, 0x00},
        {0x4507, 0x00},
        {0x4509, 0x80},
        {0x450a, 0x08},
        {0x4601, 0x04},
        {0x470f, 0x00},
        {0x4f07, 0x00},
        {0x4800, 0x20},
        {0x5000, 0x9f},
        {0x5001, 0x00},
        {0x5e00, 0x00},
        {0x5d00, 0x07},
        {0x5d01, 0x00},
        {0x0101, 0x01},
        {0x1000, 0x03},
        {0x5a08, 0x84},
};

/* Supported sensor mode configurations */
static const struct ov9282_mode supported_mode = {
        .width = 1280,
        .height = 720,
        .hblank = 250,
        .vblank = 1022,
        .vblank_min = 151,
        .vblank_max = 51540,
        .pclk = 160000000,
        .link_freq_idx = 0,
        .code = MEDIA_BUS_FMT_Y10_1X10,
        .reg_list = {
                .num_of_regs = ARRAY_SIZE(mode_1280x720_regs),
                .regs = mode_1280x720_regs,
        },
};

/**
 * to_ov9282() - ov9282 V4L2 sub-device to ov9282 device.
 * @subdev: pointer to ov9282 V4L2 sub-device
 *
 * Return: pointer to ov9282 device
 */
static inline struct ov9282 *to_ov9282(struct v4l2_subdev *subdev)
{
        return container_of(subdev, struct ov9282, sd);
}

/**
 * ov9282_read_reg() - Read registers.
 * @ov9282: pointer to ov9282 device
 * @reg: register address
 * @len: length of bytes to read. Max supported bytes is 4
 * @val: pointer to register value to be filled.
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_read_reg(struct ov9282 *ov9282, u16 reg, u32 len, u32 *val)
{
        struct i2c_client *client = v4l2_get_subdevdata(&ov9282->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[4 - len];

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

        *val = get_unaligned_be32(data_buf);

        return 0;
}

/**
 * ov9282_write_reg() - Write register
 * @ov9282: pointer to ov9282 device
 * @reg: register address
 * @len: length of bytes. Max supported bytes is 4
 * @val: register value
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_write_reg(struct ov9282 *ov9282, u16 reg, u32 len, u32 val)
{
        struct i2c_client *client = v4l2_get_subdevdata(&ov9282->sd);
        u8 buf[6] = {0};

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

        put_unaligned_be16(reg, buf);
        put_unaligned_be32(val << (8 * (4 - len)), buf + 2);
        if (i2c_master_send(client, buf, len + 2) != len + 2)
                return -EIO;

        return 0;
}

/**
 * ov9282_write_regs() - Write a list of registers
 * @ov9282: pointer to ov9282 device
 * @regs: list of registers to be written
 * @len: length of registers array
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_write_regs(struct ov9282 *ov9282,
                             const struct ov9282_reg *regs, u32 len)
{
        unsigned int i;
        int ret;

        for (i = 0; i < len; i++) {
                ret = ov9282_write_reg(ov9282, regs[i].address, 1, regs[i].val);
                if (ret)
                        return ret;
        }

        return 0;
}

/**
 * ov9282_update_controls() - Update control ranges based on streaming mode
 * @ov9282: pointer to ov9282 device
 * @mode: pointer to ov9282_mode sensor mode
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_update_controls(struct ov9282 *ov9282,
                                  const struct ov9282_mode *mode)
{
        int ret;

        ret = __v4l2_ctrl_s_ctrl(ov9282->link_freq_ctrl, mode->link_freq_idx);
        if (ret)
                return ret;

        ret = __v4l2_ctrl_s_ctrl(ov9282->hblank_ctrl, mode->hblank);
        if (ret)
                return ret;

        return __v4l2_ctrl_modify_range(ov9282->vblank_ctrl, mode->vblank_min,
                                        mode->vblank_max, 1, mode->vblank);
}

/**
 * ov9282_update_exp_gain() - Set updated exposure and gain
 * @ov9282: pointer to ov9282 device
 * @exposure: updated exposure value
 * @gain: updated analog gain value
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_update_exp_gain(struct ov9282 *ov9282, u32 exposure, u32 gain)
{
        u32 lpfr;
        int ret;

        lpfr = ov9282->vblank + ov9282->cur_mode->height;

        dev_dbg(ov9282->dev, "Set exp %u, analog gain %u, lpfr %u",
                exposure, gain, lpfr);

        ret = ov9282_write_reg(ov9282, OV9282_REG_HOLD, 1, 1);
        if (ret)
                return ret;

        ret = ov9282_write_reg(ov9282, OV9282_REG_LPFR, 2, lpfr);
        if (ret)
                goto error_release_group_hold;

        ret = ov9282_write_reg(ov9282, OV9282_REG_EXPOSURE, 3, exposure << 4);
        if (ret)
                goto error_release_group_hold;

        ret = ov9282_write_reg(ov9282, OV9282_REG_AGAIN, 1, gain);

error_release_group_hold:
        ov9282_write_reg(ov9282, OV9282_REG_HOLD, 1, 0);

        return ret;
}

/**
 * ov9282_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 ov9282_set_ctrl(struct v4l2_ctrl *ctrl)
{
        struct ov9282 *ov9282 =
                container_of(ctrl->handler, struct ov9282, ctrl_handler);
        u32 analog_gain;
        u32 exposure;
        int ret;

        switch (ctrl->id) {
        case V4L2_CID_VBLANK:
                ov9282->vblank = ov9282->vblank_ctrl->val;

                dev_dbg(ov9282->dev, "Received vblank %u, new lpfr %u",
                        ov9282->vblank,
                        ov9282->vblank + ov9282->cur_mode->height);

                ret = __v4l2_ctrl_modify_range(ov9282->exp_ctrl,
                                               OV9282_EXPOSURE_MIN,
                                               ov9282->vblank +
                                               ov9282->cur_mode->height -
                                               OV9282_EXPOSURE_OFFSET,
                                               1, OV9282_EXPOSURE_DEFAULT);
                break;
        case V4L2_CID_EXPOSURE:
                /* Set controls only if sensor is in power on state */
                if (!pm_runtime_get_if_in_use(ov9282->dev))
                        return 0;

                exposure = ctrl->val;
                analog_gain = ov9282->again_ctrl->val;

                dev_dbg(ov9282->dev, "Received exp %u, analog gain %u",
                        exposure, analog_gain);

                ret = ov9282_update_exp_gain(ov9282, exposure, analog_gain);

                pm_runtime_put(ov9282->dev);

                break;
        default:
                dev_err(ov9282->dev, "Invalid control %d", ctrl->id);
                ret = -EINVAL;
        }

        return ret;
}

/* V4l2 subdevice control ops*/
static const struct v4l2_ctrl_ops ov9282_ctrl_ops = {
        .s_ctrl = ov9282_set_ctrl,
};

/**
 * ov9282_enum_mbus_code() - Enumerate V4L2 sub-device mbus codes
 * @sd: pointer to ov9282 V4L2 sub-device structure
 * @sd_state: V4L2 sub-device configuration
 * @code: V4L2 sub-device code enumeration need to be filled
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_enum_mbus_code(struct v4l2_subdev *sd,
                                 struct v4l2_subdev_state *sd_state,
                                 struct v4l2_subdev_mbus_code_enum *code)
{
        if (code->index > 0)
                return -EINVAL;

        code->code = supported_mode.code;

        return 0;
}

/**
 * ov9282_enum_frame_size() - Enumerate V4L2 sub-device frame sizes
 * @sd: pointer to ov9282 V4L2 sub-device structure
 * @sd_state: V4L2 sub-device configuration
 * @fsize: V4L2 sub-device size enumeration need to be filled
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_enum_frame_size(struct v4l2_subdev *sd,
                                  struct v4l2_subdev_state *sd_state,
                                  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;
}

/**
 * ov9282_fill_pad_format() - Fill subdevice pad format
 *                            from selected sensor mode
 * @ov9282: pointer to ov9282 device
 * @mode: pointer to ov9282_mode sensor mode
 * @fmt: V4L2 sub-device format need to be filled
 */
static void ov9282_fill_pad_format(struct ov9282 *ov9282,
                                   const struct ov9282_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;
}

/**
 * ov9282_get_pad_format() - Get subdevice pad format
 * @sd: pointer to ov9282 V4L2 sub-device structure
 * @sd_state: V4L2 sub-device configuration
 * @fmt: V4L2 sub-device format need to be set
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_get_pad_format(struct v4l2_subdev *sd,
                                 struct v4l2_subdev_state *sd_state,
                                 struct v4l2_subdev_format *fmt)
{
        struct ov9282 *ov9282 = to_ov9282(sd);

        mutex_lock(&ov9282->mutex);

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

                framefmt = v4l2_subdev_get_try_format(sd, sd_state, fmt->pad);
                fmt->format = *framefmt;
        } else {
                ov9282_fill_pad_format(ov9282, ov9282->cur_mode, fmt);
        }

        mutex_unlock(&ov9282->mutex);

        return 0;
}

/**
 * ov9282_set_pad_format() - Set subdevice pad format
 * @sd: pointer to ov9282 V4L2 sub-device structure
 * @sd_state: V4L2 sub-device configuration
 * @fmt: V4L2 sub-device format need to be set
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_set_pad_format(struct v4l2_subdev *sd,
                                 struct v4l2_subdev_state *sd_state,
                                 struct v4l2_subdev_format *fmt)
{
        struct ov9282 *ov9282 = to_ov9282(sd);
        const struct ov9282_mode *mode;
        int ret = 0;

        mutex_lock(&ov9282->mutex);

        mode = &supported_mode;
        ov9282_fill_pad_format(ov9282, mode, fmt);

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

                framefmt = v4l2_subdev_get_try_format(sd, sd_state, fmt->pad);
                *framefmt = fmt->format;
        } else {
                ret = ov9282_update_controls(ov9282, mode);
                if (!ret)
                        ov9282->cur_mode = mode;
        }

        mutex_unlock(&ov9282->mutex);

        return ret;
}

/**
 * ov9282_init_pad_cfg() - Initialize sub-device pad configuration
 * @sd: pointer to ov9282 V4L2 sub-device structure
 * @sd_state: V4L2 sub-device configuration
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_init_pad_cfg(struct v4l2_subdev *sd,
                               struct v4l2_subdev_state *sd_state)
{
        struct ov9282 *ov9282 = to_ov9282(sd);
        struct v4l2_subdev_format fmt = { 0 };

        fmt.which = sd_state ? V4L2_SUBDEV_FORMAT_TRY : V4L2_SUBDEV_FORMAT_ACTIVE;
        ov9282_fill_pad_format(ov9282, &supported_mode, &fmt);

        return ov9282_set_pad_format(sd, sd_state, &fmt);
}

/**
 * ov9282_start_streaming() - Start sensor stream
 * @ov9282: pointer to ov9282 device
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_start_streaming(struct ov9282 *ov9282)
{
        const struct ov9282_reg_list *reg_list;
        int ret;

        /* Write sensor mode registers */
        reg_list = &ov9282->cur_mode->reg_list;
        ret = ov9282_write_regs(ov9282, reg_list->regs, reg_list->num_of_regs);
        if (ret) {
                dev_err(ov9282->dev, "fail to write initial registers");
                return ret;
        }

        /* Setup handler will write actual exposure and gain */
        ret =  __v4l2_ctrl_handler_setup(ov9282->sd.ctrl_handler);
        if (ret) {
                dev_err(ov9282->dev, "fail to setup handler");
                return ret;
        }

        /* Start streaming */
        ret = ov9282_write_reg(ov9282, OV9282_REG_MODE_SELECT,
                               1, OV9282_MODE_STREAMING);
        if (ret) {
                dev_err(ov9282->dev, "fail to start streaming");
                return ret;
        }

        return 0;
}

/**
 * ov9282_stop_streaming() - Stop sensor stream
 * @ov9282: pointer to ov9282 device
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_stop_streaming(struct ov9282 *ov9282)
{
        return ov9282_write_reg(ov9282, OV9282_REG_MODE_SELECT,
                                1, OV9282_MODE_STANDBY);
}

/**
 * ov9282_set_stream() - Enable sensor streaming
 * @sd: pointer to ov9282 subdevice
 * @enable: set to enable sensor streaming
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_set_stream(struct v4l2_subdev *sd, int enable)
{
        struct ov9282 *ov9282 = to_ov9282(sd);
        int ret;

        mutex_lock(&ov9282->mutex);

        if (ov9282->streaming == enable) {
                mutex_unlock(&ov9282->mutex);
                return 0;
        }

        if (enable) {
                ret = pm_runtime_resume_and_get(ov9282->dev);
                if (ret)
                        goto error_unlock;

                ret = ov9282_start_streaming(ov9282);
                if (ret)
                        goto error_power_off;
        } else {
                ov9282_stop_streaming(ov9282);
                pm_runtime_put(ov9282->dev);
        }

        ov9282->streaming = enable;

        mutex_unlock(&ov9282->mutex);

        return 0;

error_power_off:
        pm_runtime_put(ov9282->dev);
error_unlock:
        mutex_unlock(&ov9282->mutex);

        return ret;
}

/**
 * ov9282_detect() - Detect ov9282 sensor
 * @ov9282: pointer to ov9282 device
 *
 * Return: 0 if successful, -EIO if sensor id does not match
 */
static int ov9282_detect(struct ov9282 *ov9282)
{
        int ret;
        u32 val;

        ret = ov9282_read_reg(ov9282, OV9282_REG_ID, 2, &val);
        if (ret)
                return ret;

        if (val != OV9282_ID) {
                dev_err(ov9282->dev, "chip id mismatch: %x!=%x",
                        OV9282_ID, val);
                return -ENXIO;
        }

        return 0;
}

/**
 * ov9282_parse_hw_config() - Parse HW configuration and check if supported
 * @ov9282: pointer to ov9282 device
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_parse_hw_config(struct ov9282 *ov9282)
{
        struct fwnode_handle *fwnode = dev_fwnode(ov9282->dev);
        struct v4l2_fwnode_endpoint bus_cfg = {
                .bus_type = V4L2_MBUS_CSI2_DPHY
        };
        struct fwnode_handle *ep;
        unsigned long rate;
        unsigned int i;
        int ret;

        if (!fwnode)
                return -ENXIO;

        /* Request optional reset pin */
        ov9282->reset_gpio = devm_gpiod_get_optional(ov9282->dev, "reset",
                                                     GPIOD_OUT_LOW);
        if (IS_ERR(ov9282->reset_gpio)) {
                dev_err(ov9282->dev, "failed to get reset gpio %ld",
                        PTR_ERR(ov9282->reset_gpio));
                return PTR_ERR(ov9282->reset_gpio);
        }

        /* Get sensor input clock */
        ov9282->inclk = devm_clk_get(ov9282->dev, NULL);
        if (IS_ERR(ov9282->inclk)) {
                dev_err(ov9282->dev, "could not get inclk");
                return PTR_ERR(ov9282->inclk);
        }

        rate = clk_get_rate(ov9282->inclk);
        if (rate != OV9282_INCLK_RATE) {
                dev_err(ov9282->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 != OV9282_NUM_DATA_LANES) {
                dev_err(ov9282->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(ov9282->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] == OV9282_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 ov9282_video_ops = {
        .s_stream = ov9282_set_stream,
};

static const struct v4l2_subdev_pad_ops ov9282_pad_ops = {
        .init_cfg = ov9282_init_pad_cfg,
        .enum_mbus_code = ov9282_enum_mbus_code,
        .enum_frame_size = ov9282_enum_frame_size,
        .get_fmt = ov9282_get_pad_format,
        .set_fmt = ov9282_set_pad_format,
};

static const struct v4l2_subdev_ops ov9282_subdev_ops = {
        .video = &ov9282_video_ops,
        .pad = &ov9282_pad_ops,
};

/**
 * ov9282_power_on() - Sensor power on sequence
 * @dev: pointer to i2c device
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_power_on(struct device *dev)
{
        struct v4l2_subdev *sd = dev_get_drvdata(dev);
        struct ov9282 *ov9282 = to_ov9282(sd);
        int ret;

        usleep_range(400, 600);

        gpiod_set_value_cansleep(ov9282->reset_gpio, 1);

        ret = clk_prepare_enable(ov9282->inclk);
        if (ret) {
                dev_err(ov9282->dev, "fail to enable inclk");
                goto error_reset;
        }

        usleep_range(400, 600);

        return 0;

error_reset:
        gpiod_set_value_cansleep(ov9282->reset_gpio, 0);

        return ret;
}

/**
 * ov9282_power_off() - Sensor power off sequence
 * @dev: pointer to i2c device
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_power_off(struct device *dev)
{
        struct v4l2_subdev *sd = dev_get_drvdata(dev);
        struct ov9282 *ov9282 = to_ov9282(sd);

        gpiod_set_value_cansleep(ov9282->reset_gpio, 0);

        clk_disable_unprepare(ov9282->inclk);

        return 0;
}

/**
 * ov9282_init_controls() - Initialize sensor subdevice controls
 * @ov9282: pointer to ov9282 device
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_init_controls(struct ov9282 *ov9282)
{
        struct v4l2_ctrl_handler *ctrl_hdlr = &ov9282->ctrl_handler;
        const struct ov9282_mode *mode = ov9282->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 = &ov9282->mutex;

        /* Initialize exposure and gain */
        lpfr = mode->vblank + mode->height;
        ov9282->exp_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
                                             &ov9282_ctrl_ops,
                                             V4L2_CID_EXPOSURE,
                                             OV9282_EXPOSURE_MIN,
                                             lpfr - OV9282_EXPOSURE_OFFSET,
                                             OV9282_EXPOSURE_STEP,
                                             OV9282_EXPOSURE_DEFAULT);

        ov9282->again_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
                                               &ov9282_ctrl_ops,
                                               V4L2_CID_ANALOGUE_GAIN,
                                               OV9282_AGAIN_MIN,
                                               OV9282_AGAIN_MAX,
                                               OV9282_AGAIN_STEP,
                                               OV9282_AGAIN_DEFAULT);

        v4l2_ctrl_cluster(2, &ov9282->exp_ctrl);

        ov9282->vblank_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
                                                &ov9282_ctrl_ops,
                                                V4L2_CID_VBLANK,
                                                mode->vblank_min,
                                                mode->vblank_max,
                                                1, mode->vblank);

        /* Read only controls */
        ov9282->pclk_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
                                              &ov9282_ctrl_ops,
                                              V4L2_CID_PIXEL_RATE,
                                              mode->pclk, mode->pclk,
                                              1, mode->pclk);

        ov9282->link_freq_ctrl = v4l2_ctrl_new_int_menu(ctrl_hdlr,
                                                        &ov9282_ctrl_ops,
                                                        V4L2_CID_LINK_FREQ,
                                                        ARRAY_SIZE(link_freq) -
                                                        1,
                                                        mode->link_freq_idx,
                                                        link_freq);
        if (ov9282->link_freq_ctrl)
                ov9282->link_freq_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;

        ov9282->hblank_ctrl = v4l2_ctrl_new_std(ctrl_hdlr,
                                                &ov9282_ctrl_ops,
                                                V4L2_CID_HBLANK,
                                                OV9282_REG_MIN,
                                                OV9282_REG_MAX,
                                                1, mode->hblank);
        if (ov9282->hblank_ctrl)
                ov9282->hblank_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;

        if (ctrl_hdlr->error) {
                dev_err(ov9282->dev, "control init failed: %d",
                        ctrl_hdlr->error);
                v4l2_ctrl_handler_free(ctrl_hdlr);
                return ctrl_hdlr->error;
        }

        ov9282->sd.ctrl_handler = ctrl_hdlr;

        return 0;
}

/**

 * ov9282_probe() - I2C client device binding
 * @client: pointer to i2c client device
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_probe(struct i2c_client *client)
{
        struct ov9282 *ov9282;
        int ret;

        ov9282 = devm_kzalloc(&client->dev, sizeof(*ov9282), GFP_KERNEL);
        if (!ov9282)
                return -ENOMEM;

        ov9282->dev = &client->dev;

        /* Initialize subdev */
        v4l2_i2c_subdev_init(&ov9282->sd, client, &ov9282_subdev_ops);

        ret = ov9282_parse_hw_config(ov9282);
        if (ret) {
                dev_err(ov9282->dev, "HW configuration is not supported");
                return ret;
        }

        mutex_init(&ov9282->mutex);

        ret = ov9282_power_on(ov9282->dev);
        if (ret) {
                dev_err(ov9282->dev, "failed to power-on the sensor");
                goto error_mutex_destroy;
        }

        /* Check module identity */
        ret = ov9282_detect(ov9282);
        if (ret) {
                dev_err(ov9282->dev, "failed to find sensor: %d", ret);
                goto error_power_off;
        }

        /* Set default mode to max resolution */
        ov9282->cur_mode = &supported_mode;
        ov9282->vblank = ov9282->cur_mode->vblank;

        ret = ov9282_init_controls(ov9282);
        if (ret) {
                dev_err(ov9282->dev, "failed to init controls: %d", ret);
                goto error_power_off;
        }

        /* Initialize subdev */
        ov9282->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
        ov9282->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;

        /* Initialize source pad */
        ov9282->pad.flags = MEDIA_PAD_FL_SOURCE;
        ret = media_entity_pads_init(&ov9282->sd.entity, 1, &ov9282->pad);
        if (ret) {
                dev_err(ov9282->dev, "failed to init entity pads: %d", ret);
                goto error_handler_free;
        }

        ret = v4l2_async_register_subdev_sensor(&ov9282->sd);
        if (ret < 0) {
                dev_err(ov9282->dev,
                        "failed to register async subdev: %d", ret);
                goto error_media_entity;
        }

        pm_runtime_set_active(ov9282->dev);
        pm_runtime_enable(ov9282->dev);
        pm_runtime_idle(ov9282->dev);

        return 0;

error_media_entity:
        media_entity_cleanup(&ov9282->sd.entity);
error_handler_free:
        v4l2_ctrl_handler_free(ov9282->sd.ctrl_handler);
error_power_off:
        ov9282_power_off(ov9282->dev);
error_mutex_destroy:
        mutex_destroy(&ov9282->mutex);

        return ret;
}

/**
 * ov9282_remove() - I2C client device unbinding
 * @client: pointer to I2C client device
 *
 * Return: 0 if successful, error code otherwise.
 */
static int ov9282_remove(struct i2c_client *client)
{
        struct v4l2_subdev *sd = i2c_get_clientdata(client);
        struct ov9282 *ov9282 = to_ov9282(sd);

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

        pm_runtime_disable(&client->dev);
        if (!pm_runtime_status_suspended(&client->dev))
                ov9282_power_off(&client->dev);
        pm_runtime_set_suspended(&client->dev);

        mutex_destroy(&ov9282->mutex);

        return 0;
}

static const struct dev_pm_ops ov9282_pm_ops = {
        SET_RUNTIME_PM_OPS(ov9282_power_off, ov9282_power_on, NULL)
};

static const struct of_device_id ov9282_of_match[] = {
        { .compatible = "ovti,ov9282" },
        { }
};

MODULE_DEVICE_TABLE(of, ov9282_of_match);

static struct i2c_driver ov9282_driver = {
        .probe_new = ov9282_probe,
        .remove = ov9282_remove,
        .driver = {
                .name = "ov9282",
                .pm = &ov9282_pm_ops,
                .of_match_table = ov9282_of_match,
        },
};

module_i2c_driver(ov9282_driver);

MODULE_DESCRIPTION("OmniVision ov9282 sensor driver");
MODULE_LICENSE("GPL");