root/drivers/media/i2c/ov2735.c
// SPDX-License-Identifier: GPL-2.0
/*
 * V4L2 Support for the OV2735
 *
 * Copyright (C) 2025 Silicon Signals Pvt. Ltd.
 *
 * Based on Rockchip ov2735 Camera Driver
 * Copyright (C) 2017 Fuzhou Rockchip Electronics Co., Ltd.
 *
 * Inspired from ov8858, imx219, imx283 camera drivers.
 */

#include <linux/array_size.h>
#include <linux/bitops.h>
#include <linux/cleanup.h>
#include <linux/clk.h>
#include <linux/container_of.h>
#include <linux/delay.h>
#include <linux/device/devres.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/pm_runtime.h>
#include <linux/property.h>
#include <linux/regulator/consumer.h>
#include <linux/units.h>
#include <linux/types.h>
#include <linux/time.h>

#include <media/v4l2-cci.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
#include <media/v4l2-fwnode.h>
#include <media/v4l2-mediabus.h>

#define OV2735_XCLK_FREQ                        (24 * HZ_PER_MHZ)

/* Add page number in CCI private bits [31:28] of the register address */
#define OV2735_PAGE_REG8(p, x)  (((p) << CCI_REG_PRIVATE_SHIFT) | CCI_REG8(x))
#define OV2735_PAGE_REG16(p, x) (((p) << CCI_REG_PRIVATE_SHIFT) | CCI_REG16(x))

#define OV2735_REG_PAGE_SELECT                  CCI_REG8(0xfd)

/* Page 0 */
#define OV2735_REG_CHIPID                       OV2735_PAGE_REG16(0x00, 0x02)
#define OV2735_CHIPID                           0x2735

#define OV2735_REG_SOFT_RESET                   OV2735_PAGE_REG8(0x00, 0x20)

/* Clock Settings */
#define OV2735_REG_PLL_CTRL                     OV2735_PAGE_REG8(0x00, 0x2f)
#define OV2735_PLL_CTRL_ENABLE                  0x7f
#define OV2735_REG_PLL_OUTDIV                   OV2735_PAGE_REG8(0x00, 0x34)
#define OV2735_REG_CLK_MODE                     OV2735_PAGE_REG8(0x00, 0x30)
#define OV2735_REG_CLOCK_REG1                   OV2735_PAGE_REG8(0x00, 0x33)
#define OV2735_REG_CLOCK_REG2                   OV2735_PAGE_REG8(0x00, 0x35)

/* Page 1 */
#define OV2735_REG_STREAM_CTRL                  OV2735_PAGE_REG8(0x01, 0xa0)
#define OV2735_STREAM_CTRL_ON                   0x01
#define OV2735_STREAM_CTRL_OFF                  0x00

#define OV2735_REG_UPDOWN_MIRROR                OV2735_PAGE_REG8(0x01, 0x3f)
#define OV2735_REG_BINNING_DAC_CODE_MODE        OV2735_PAGE_REG8(0x01, 0x30)
#define OV2735_REG_FRAME_LENGTH                 OV2735_PAGE_REG16(0x01, 0x0e)
#define OV2735_FRAME_LENGTH_MAX                 0x0fff
#define OV2735_REG_FRAME_EXP_SEPERATE_EN        OV2735_PAGE_REG8(0x01, 0x0d)
#define OV2735_FRAME_EXP_SEPERATE_EN            0x10
#define OV2735_REG_FRAME_SYNC                   OV2735_PAGE_REG8(0x01, 0x01)

#define OV2735_REG_HBLANK                       OV2735_PAGE_REG16(0x01, 0x09)

#define OV2735_REG_HS_MIPI                      OV2735_PAGE_REG8(0x01, 0xb1)
#define OV2735_REG_MIPI_CTRL1                   OV2735_PAGE_REG8(0x01, 0x92)
#define OV2735_REG_MIPI_CTRL2                   OV2735_PAGE_REG8(0x01, 0x94)
#define OV2735_REG_MIPI_CTRL3                   OV2735_PAGE_REG8(0x01, 0xa1)
#define OV2735_REG_MIPI_CTRL4                   OV2735_PAGE_REG8(0x01, 0xb2)
#define OV2735_REG_MIPI_CTRL5                   OV2735_PAGE_REG8(0x01, 0xb3)
#define OV2735_REG_MIPI_CTRL6                   OV2735_PAGE_REG8(0x01, 0xb4)
#define OV2735_REG_MIPI_CTRL7                   OV2735_PAGE_REG8(0x01, 0xb5)
#define OV2735_REG_HIGH_SPEED                   OV2735_PAGE_REG8(0x01, 0x9d)
#define OV2735_REG_PREPARE                      OV2735_PAGE_REG8(0x01, 0x95)
#define OV2735_REG_R_HS_ZERO                    OV2735_PAGE_REG8(0x01, 0x96)
#define OV2735_REG_TRAIL                        OV2735_PAGE_REG8(0x01, 0x98)
#define OV2735_REG_R_CLK_ZERO                   OV2735_PAGE_REG8(0x01, 0x9c)
#define OV2735_REG_MIPI_COLOMN_NUMBER           OV2735_PAGE_REG16(0x01, 0x8e)
#define OV2735_REG_MIPI_LINE_NUMBER             OV2735_PAGE_REG16(0x01, 0x90)

/* Timing control registers */
#define OV2735_REG_TIMING_CTRL2                 OV2735_PAGE_REG8(0x01, 0x1a)
#define OV2735_REG_TIMING_CTRL3                 OV2735_PAGE_REG8(0x01, 0x1c)
#define OV2735_REG_TIMING_CTRL1                 OV2735_PAGE_REG8(0x01, 0x16)
#define OV2735_REG_RST_NUM                      OV2735_PAGE_REG16(0x01, 0x10)
#define OV2735_REG_RST_NUM2                     OV2735_PAGE_REG16(0x01, 0x32)
#define OV2735_REG_BOOST_EN                     OV2735_PAGE_REG8(0x01, 0xd0)
#define OV2735_REG_B2_NUM                       OV2735_PAGE_REG16(0x01, 0xd1)
#define OV2735_REG_B4_NUM                       OV2735_PAGE_REG16(0x01, 0xd3)
#define OV2735_REG_PIXEL_CYCLE_P0               OV2735_PAGE_REG8(0x01, 0x50)
#define OV2735_REG_PIXEL_CYCLE_P1               OV2735_PAGE_REG8(0x01, 0x51)
#define OV2735_REG_PIXEL_CYCLE_P2               OV2735_PAGE_REG8(0x01, 0x52)
#define OV2735_REG_PIXEL_CYCLE_P3               OV2735_PAGE_REG8(0x01, 0x53)
#define OV2735_REG_PIXEL_CYCLE_P5               OV2735_PAGE_REG8(0x01, 0x55)
#define OV2735_REG_PIXEL_CYCLE_P7               OV2735_PAGE_REG16(0x01, 0x57)
#define OV2735_REG_PIXEL_CYCLE_P9               OV2735_PAGE_REG8(0x01, 0x5a)
#define OV2735_REG_PIXEL_CYCLE_P10              OV2735_PAGE_REG8(0x01, 0x5b)
#define OV2735_REG_PIXEL_CYCLE_P12              OV2735_PAGE_REG8(0x01, 0x5d)
#define OV2735_REG_PIXEL_CYCLE_P18              OV2735_PAGE_REG8(0x01, 0x64)
#define OV2735_REG_PIXEL_CYCLE_P20              OV2735_PAGE_REG8(0x01, 0x66)
#define OV2735_REG_PIXEL_CYCLE_P22              OV2735_PAGE_REG8(0x01, 0x68)
#define OV2735_REG_PIXEL_CYCLE_P33              OV2735_PAGE_REG16(0x01, 0x74)
#define OV2735_REG_PIXEL_CYCLE_P34              OV2735_PAGE_REG8(0x01, 0x76)
#define OV2735_REG_PIXEL_CYCLE_P35_P36          OV2735_PAGE_REG8(0x01, 0x77)
#define OV2735_REG_PIXEL_CYCLE_P37_P38          OV2735_PAGE_REG8(0x01, 0x78)
#define OV2735_REG_PIXEL_CYCLE_P31              OV2735_PAGE_REG8(0x01, 0x72)
#define OV2735_REG_PIXEL_CYCLE_P32              OV2735_PAGE_REG8(0x01, 0x73)
#define OV2735_REG_PIXEL_CYCLE_P44              OV2735_PAGE_REG8(0x01, 0x7d)
#define OV2735_REG_PIXEL_CYCLE_P45              OV2735_PAGE_REG8(0x01, 0x7e)
#define OV2735_REG_PIXEL_BIAS_CTRL_RH_RL        OV2735_PAGE_REG8(0x01, 0x8a)
#define OV2735_REG_PIXEL_BIAS_CTRL_SH_SL        OV2735_PAGE_REG8(0x01, 0x8b)

/* Analog Control registers */
#define OV2735_REG_ICOMP                        OV2735_PAGE_REG8(0x01, 0x19)
#define OV2735_REG_PCP_RST_SEL                  OV2735_PAGE_REG8(0x01, 0x21)
#define OV2735_REG_VNCP                         OV2735_PAGE_REG8(0x01, 0x20)
#define OV2735_REG_ANALOG_CTRL3                 OV2735_PAGE_REG8(0x01, 0x25)
#define OV2735_REG_ANALOG_CTRL4                 OV2735_PAGE_REG8(0x01, 0x26)
#define OV2735_REG_ANALOG_CTRL5                 OV2735_PAGE_REG8(0x01, 0x29)
#define OV2735_REG_ANALOG_CTRL6                 OV2735_PAGE_REG8(0x01, 0x2a)
#define OV2735_REG_ANALOG_CTRL8                 OV2735_PAGE_REG8(0x01, 0x2c)

/* BLC registers */
#define OV2735_REG_BLC_GAIN_BLUE                OV2735_PAGE_REG8(0x01, 0x86)
#define OV2735_REG_BLC_GAIN_RED                 OV2735_PAGE_REG8(0x01, 0x87)
#define OV2735_REG_BLC_GAIN_GR                  OV2735_PAGE_REG8(0x01, 0x88)
#define OV2735_REG_BLC_GAIN_GB                  OV2735_PAGE_REG8(0x01, 0x89)
#define OV2735_REG_GB_SUBOFFSET                 OV2735_PAGE_REG8(0x01, 0xf0)
#define OV2735_REG_BLUE_SUBOFFSET               OV2735_PAGE_REG8(0x01, 0xf1)
#define OV2735_REG_RED_SUBOFFSET                OV2735_PAGE_REG8(0x01, 0xf2)
#define OV2735_REG_GR_SUBOFFSET                 OV2735_PAGE_REG8(0x01, 0xf3)
#define OV2735_REG_BLC_BPC_TH_P                 OV2735_PAGE_REG8(0x01, 0xfc)
#define OV2735_REG_BLC_BPC_TH_N                 OV2735_PAGE_REG8(0x01, 0xfe)
#define OV2735_REG_ABL                          OV2735_PAGE_REG8(0x01, 0xfb)

#define OV2735_REG_TEST_PATTERN                 OV2735_PAGE_REG8(0x01, 0xb2)
#define OV2735_TEST_PATTERN_ENABLE              0x01
#define OV2735_TEST_PATTERN_DISABLE             0xfe

#define OV2735_REG_LONG_EXPOSURE                OV2735_PAGE_REG16(0x01, 0x03)
#define OV2735_EXPOSURE_MIN                     4
#define OV2735_EXPOSURE_STEP                    1
#define OV2735_EXPOSURE_MARGIN                  4

#define OV2735_REG_ANALOG_GAIN                  OV2735_PAGE_REG8(0x01, 0x24)
#define OV2735_ANALOG_GAIN_MIN                  0x10
#define OV2735_ANALOG_GAIN_MAX                  0xff
#define OV2735_ANALOG_GAIN_STEP                 1
#define OV2735_ANALOG_GAIN_DEFAULT              0x10

/* Page 2 */
#define OV2735_REG_V_START                      OV2735_PAGE_REG16(0x02, 0xa0)
#define OV2735_REG_V_SIZE                       OV2735_PAGE_REG16(0x02, 0xa2)
#define OV2735_REG_H_START                      OV2735_PAGE_REG16(0x02, 0xa4)
#define OV2735_REG_H_SIZE                       OV2735_PAGE_REG16(0x02, 0xa6)

#define OV2735_LINK_FREQ_420MHZ                 (420 * HZ_PER_MHZ)
#define OV2735_PIXEL_RATE                       (168 * HZ_PER_MHZ)

/* OV2735 native and active pixel array size */
static const struct v4l2_rect ov2735_native_area = {
        .top = 0,
        .left = 0,
        .width = 1936,
        .height = 1096,
};

static const struct v4l2_rect ov2735_active_area = {
        .top = 8,
        .left = 8,
        .width = 1920,
        .height = 1080,
};

static const char * const ov2735_supply_name[] = {
        "avdd",         /* Analog power */
        "dovdd",        /* Digital I/O power */
        "dvdd",         /* Digital core power */
};

/* PLL_OUT = [PLL_IN * (pll_nc +3)] / [(pll_mc + 1) * (pll_outdiv + 1)] */
struct ov2735_pll_parameters {
        u8 pll_nc;
        u8 pll_mc;
        u8 pll_outdiv;
};

struct ov2735 {
        struct device *dev;
        struct regmap *cci;
        struct v4l2_subdev sd;
        struct media_pad pad;
        struct clk *xclk;
        struct gpio_desc *reset_gpio;
        struct gpio_desc *enable_gpio;
        struct regulator_bulk_data supplies[ARRAY_SIZE(ov2735_supply_name)];

        /* V4L2 Controls */
        struct v4l2_ctrl_handler handler;
        struct v4l2_ctrl *link_freq;
        struct v4l2_ctrl *pixel_rate;
        struct v4l2_ctrl *hblank;
        struct v4l2_ctrl *vblank;
        struct v4l2_ctrl *gain;
        struct v4l2_ctrl *exposure;
        struct v4l2_ctrl *test_pattern;

        u32 link_freq_index;

        u8 current_page;
        struct mutex page_lock;
};

struct ov2735_mode {
        u32 width;
        u32 height;
        u32 hts_def;
        u32 vts_def;
        u32 exp_def;
        struct v4l2_rect crop;
};

static const struct cci_reg_sequence ov2735_common_regs[] = {
        { OV2735_REG_CLK_MODE,                  0x15 },
        { OV2735_REG_CLOCK_REG1,                0x01 },
        { OV2735_REG_CLOCK_REG2,                0x20 },
        { OV2735_REG_BINNING_DAC_CODE_MODE,     0x00 },
        { OV2735_REG_ABL,                       0x73 },
        { OV2735_REG_FRAME_SYNC,                0x01 },

        /* Timing ctrl */
        { OV2735_REG_TIMING_CTRL2,              0x6b },
        { OV2735_REG_TIMING_CTRL3,              0xea },
        { OV2735_REG_TIMING_CTRL1,              0x0c },
        { OV2735_REG_RST_NUM,                   0x0063 },
        { OV2735_REG_RST_NUM2,                  0x006f },
        { OV2735_REG_BOOST_EN,                  0x02 },
        { OV2735_REG_B2_NUM,                    0x0120 },
        { OV2735_REG_B4_NUM,                    0x042a },
        { OV2735_REG_PIXEL_CYCLE_P0,            0x00 },
        { OV2735_REG_PIXEL_CYCLE_P1,            0x2c },
        { OV2735_REG_PIXEL_CYCLE_P2,            0x29 },
        { OV2735_REG_PIXEL_CYCLE_P3,            0x00 },
        { OV2735_REG_PIXEL_CYCLE_P5,            0x44 },
        { OV2735_REG_PIXEL_CYCLE_P7,            0x0029 },
        { OV2735_REG_PIXEL_CYCLE_P9,            0x00 },
        { OV2735_REG_PIXEL_CYCLE_P10,           0x00 },
        { OV2735_REG_PIXEL_CYCLE_P12,           0x00 },
        { OV2735_REG_PIXEL_CYCLE_P18,           0x2f },
        { OV2735_REG_PIXEL_CYCLE_P20,           0x62 },
        { OV2735_REG_PIXEL_CYCLE_P22,           0x5b },
        { OV2735_REG_PIXEL_CYCLE_P33,           0x0046 },
        { OV2735_REG_PIXEL_CYCLE_P34,           0x36 },
        { OV2735_REG_PIXEL_CYCLE_P35_P36,       0x4f },
        { OV2735_REG_PIXEL_CYCLE_P37_P38,       0xef },
        { OV2735_REG_PIXEL_CYCLE_P31,           0xcf },
        { OV2735_REG_PIXEL_CYCLE_P32,           0x36 },
        { OV2735_REG_PIXEL_CYCLE_P44,           0x0d },
        { OV2735_REG_PIXEL_CYCLE_P45,           0x0d },
        { OV2735_REG_PIXEL_BIAS_CTRL_RH_RL,     0x77 },
        { OV2735_REG_PIXEL_BIAS_CTRL_SH_SL,     0x77 },

        /* Analog ctrl */
        { OV2735_REG_ANALOG_CTRL4,              0x5a },
        { OV2735_REG_ANALOG_CTRL5,              0x01 },
        { OV2735_REG_ANALOG_CTRL6,              0xd2 },
        { OV2735_REG_ANALOG_CTRL8,              0x40 },
        { OV2735_REG_PCP_RST_SEL,               0x00 },
        { OV2735_REG_ICOMP,                     0xc3 },

        { OV2735_REG_HS_MIPI,                   0x83 },
        { OV2735_REG_MIPI_CTRL5,                0x0b },
        { OV2735_REG_MIPI_CTRL6,                0x14 },
        { OV2735_REG_HIGH_SPEED,                0x40 },
        { OV2735_REG_MIPI_CTRL3,                0x05 },
        { OV2735_REG_MIPI_CTRL2,                0x44 },
        { OV2735_REG_PREPARE,                   0x33 },
        { OV2735_REG_R_HS_ZERO,                 0x1f },
        { OV2735_REG_TRAIL,                     0x45 },
        { OV2735_REG_R_CLK_ZERO,                0x10 },
        { OV2735_REG_MIPI_CTRL7,                0x70 },
        { OV2735_REG_ANALOG_CTRL3,              0xe0 },
        { OV2735_REG_VNCP,                      0x7b },

        /* BLC */
        { OV2735_REG_BLC_GAIN_BLUE,             0x77 },
        { OV2735_REG_BLC_GAIN_GB,               0x77 },
        { OV2735_REG_BLC_GAIN_RED,              0x74 },
        { OV2735_REG_BLC_GAIN_GR,               0x74 },
        { OV2735_REG_BLC_BPC_TH_P,              0xe0 },
        { OV2735_REG_BLC_BPC_TH_N,              0xe0 },
        { OV2735_REG_GB_SUBOFFSET,              0x40 },
        { OV2735_REG_BLUE_SUBOFFSET,            0x40 },
        { OV2735_REG_RED_SUBOFFSET,             0x40 },
        { OV2735_REG_GR_SUBOFFSET,              0x40 },
};

static const struct ov2735_mode supported_modes[] = {
        {
                .width = 1920,
                .height = 1080,
                .exp_def = 399,
                .hts_def = 2200,
                .vts_def = 2545,
                .crop = {
                        .top = 8,
                        .left = 8,
                        .width = 1920,
                        .height = 1080,
                },
        },
};

static const s64 link_freq_menu_items[] = {
        OV2735_LINK_FREQ_420MHZ,
};

static const struct ov2735_pll_parameters pll_configs[] = {
        /* For 420MHz pll_configs */
        {
                .pll_nc = 4,
                .pll_mc = 0,
                .pll_outdiv = 1,
        },
};

static const char * const ov2735_test_pattern_menu[] = {
        "Disabled",
        "Vertical Color",
};

static int ov2735_page_access(struct ov2735 *ov2735, u32 reg, int *err)
{
        u8 page = reg >> CCI_REG_PRIVATE_SHIFT;
        int ret = 0;

        if (err && *err)
                return *err;

        guard(mutex)(&ov2735->page_lock);

        /* Perform page access before read/write */
        if (ov2735->current_page == page)
                return ret;

        ret = cci_write(ov2735->cci, OV2735_REG_PAGE_SELECT, page, err);
        if (!ret)
                ov2735->current_page = page;

        return ret;
}

static int ov2735_read(struct ov2735 *ov2735, u32 reg, u64 *val, int *err)
{
        u32 addr = reg & ~CCI_REG_PRIVATE_MASK;
        int ret;

        ret = ov2735_page_access(ov2735, reg, err);
        if (ret)
                return ret;

        return cci_read(ov2735->cci, addr, val, err);
}

static int ov2735_write(struct ov2735 *ov2735, u32 reg, u64 val, int *err)
{
        u32 addr = reg & ~CCI_REG_PRIVATE_MASK;
        int ret;

        ret = ov2735_page_access(ov2735, reg, err);
        if (ret)
                return ret;

        return cci_write(ov2735->cci, addr, val, err);
}

static int ov2735_multi_reg_write(struct ov2735 *ov2735,
                                  const struct cci_reg_sequence *regs,
                                  unsigned int num_regs, int *err)
{
        unsigned int i;
        int ret;

        for (i = 0; i < num_regs; i++) {
                ret = ov2735_write(ov2735, regs[i].reg, regs[i].val, err);
                if (ret)
                        return ret;
        }

        return 0;
}

static inline struct ov2735 *to_ov2735(struct v4l2_subdev *_sd)
{
        return container_of_const(_sd, struct ov2735, sd);
}

static int ov2735_enable_test_pattern(struct ov2735 *ov2735, u32 pattern)
{
        int ret;
        u64 val;

        ret = ov2735_read(ov2735, OV2735_REG_TEST_PATTERN, &val, NULL);
        if (ret)
                return ret;

        switch (pattern) {
        case 0:
                val &= ~OV2735_TEST_PATTERN_ENABLE;
                break;
        case 1:
                val |= OV2735_TEST_PATTERN_ENABLE;
                break;
        }

        return ov2735_write(ov2735, OV2735_REG_TEST_PATTERN, val, NULL);
}

static int ov2735_set_ctrl(struct v4l2_ctrl *ctrl)
{
        struct ov2735 *ov2735 =
                container_of_const(ctrl->handler, struct ov2735, handler);
        struct v4l2_mbus_framefmt *fmt;
        struct v4l2_subdev_state *state;
        u64 vts;
        int ret = 0;

        state = v4l2_subdev_get_locked_active_state(&ov2735->sd);
        fmt = v4l2_subdev_state_get_format(state, 0);

        if (ctrl->id == V4L2_CID_VBLANK) {
                /* Honour the VBLANK limits when setting exposure */
                s64 max = fmt->height + ctrl->val - OV2735_EXPOSURE_MARGIN;

                ret = __v4l2_ctrl_modify_range(ov2735->exposure,
                                               ov2735->exposure->minimum, max,
                                               ov2735->exposure->step,
                                               ov2735->exposure->default_value);
                if (ret)
                        return ret;
        }

        if (pm_runtime_get_if_in_use(ov2735->dev) == 0)
                return 0;

        switch (ctrl->id) {
        case V4L2_CID_EXPOSURE:
                ov2735_write(ov2735, OV2735_REG_LONG_EXPOSURE, ctrl->val, &ret);
                break;
        case V4L2_CID_ANALOGUE_GAIN:
                ov2735_write(ov2735, OV2735_REG_ANALOG_GAIN, ctrl->val, &ret);
                break;
        case V4L2_CID_HBLANK:
                ov2735_write(ov2735, OV2735_REG_HBLANK, ctrl->val, &ret);
                break;
        case V4L2_CID_VBLANK:
                vts = ctrl->val + fmt->height;
                ov2735_write(ov2735, OV2735_REG_FRAME_EXP_SEPERATE_EN,
                             OV2735_FRAME_EXP_SEPERATE_EN, &ret);
                ov2735_write(ov2735, OV2735_REG_FRAME_LENGTH, vts, &ret);
                break;
        case V4L2_CID_TEST_PATTERN:
                ret = ov2735_enable_test_pattern(ov2735, ctrl->val);
                break;
        default:
                ret = -EINVAL;
                break;
        }
        ov2735_write(ov2735, OV2735_REG_FRAME_SYNC, 0x01, &ret);

        pm_runtime_put(ov2735->dev);

        return ret;
}

static const struct v4l2_ctrl_ops ov2735_ctrl_ops = {
        .s_ctrl = ov2735_set_ctrl,
};

static int ov2735_init_controls(struct ov2735 *ov2735)
{
        struct v4l2_ctrl_handler *ctrl_hdlr;
        struct v4l2_fwnode_device_properties props;
        const struct ov2735_mode *mode = &supported_modes[0];
        u64 hblank_def, vblank_def, exp_max;
        int ret;

        ctrl_hdlr = &ov2735->handler;
        v4l2_ctrl_handler_init(ctrl_hdlr, 9);

        ov2735->pixel_rate = v4l2_ctrl_new_std(ctrl_hdlr, &ov2735_ctrl_ops,
                                               V4L2_CID_PIXEL_RATE, 0,
                                               OV2735_PIXEL_RATE, 1,
                                               OV2735_PIXEL_RATE);

        ov2735->link_freq = v4l2_ctrl_new_int_menu(ctrl_hdlr, &ov2735_ctrl_ops,
                                                   V4L2_CID_LINK_FREQ,
                                                   ov2735->link_freq_index,
                                                   0, link_freq_menu_items);
        if (ov2735->link_freq)
                ov2735->link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY;

        hblank_def = mode->hts_def - mode->width;
        ov2735->hblank = v4l2_ctrl_new_std(ctrl_hdlr, &ov2735_ctrl_ops,
                                           V4L2_CID_HBLANK, hblank_def,
                                           hblank_def, 1, hblank_def);

        vblank_def = mode->vts_def - mode->height;
        ov2735->vblank = v4l2_ctrl_new_std(ctrl_hdlr, &ov2735_ctrl_ops,
                                           V4L2_CID_VBLANK, vblank_def,
                                           OV2735_FRAME_LENGTH_MAX - mode->height,
                                           1, vblank_def);

        exp_max = mode->vts_def - OV2735_EXPOSURE_MARGIN;
        ov2735->exposure =
                v4l2_ctrl_new_std(ctrl_hdlr, &ov2735_ctrl_ops,
                                  V4L2_CID_EXPOSURE,
                                  OV2735_EXPOSURE_MIN, exp_max,
                                  OV2735_EXPOSURE_STEP, mode->exp_def);

        ov2735->gain =
                v4l2_ctrl_new_std(ctrl_hdlr, &ov2735_ctrl_ops,
                                  V4L2_CID_ANALOGUE_GAIN, OV2735_ANALOG_GAIN_MIN,
                                  OV2735_ANALOG_GAIN_MAX, OV2735_ANALOG_GAIN_STEP,
                                  OV2735_ANALOG_GAIN_DEFAULT);

        ov2735->test_pattern =
                v4l2_ctrl_new_std_menu_items(ctrl_hdlr, &ov2735_ctrl_ops,
                                             V4L2_CID_TEST_PATTERN,
                                             ARRAY_SIZE(ov2735_test_pattern_menu) - 1,
                                             0, 0, ov2735_test_pattern_menu);

        if (ctrl_hdlr->error) {
                ret = ctrl_hdlr->error;
                dev_err(ov2735->dev, "control init failed (%d)\n", ret);
                goto err_handler_free;
        }

        ret = v4l2_fwnode_device_parse(ov2735->dev, &props);
        if (ret)
                goto err_handler_free;

        ret = v4l2_ctrl_new_fwnode_properties(ctrl_hdlr,
                                              &ov2735_ctrl_ops, &props);
        if (ret)
                goto err_handler_free;

        ov2735->sd.ctrl_handler = ctrl_hdlr;

        return 0;

err_handler_free:
        v4l2_ctrl_handler_free(ctrl_hdlr);

        return ret;
}

static int ov2735_set_pll_ctrl(struct ov2735 *ov2735)
{
        const struct ov2735_pll_parameters *pll_parameters;
        u8 pll_ctrl;
        u8 pll_outdiv;
        int ret = 0;

        pll_parameters = &pll_configs[ov2735->link_freq_index];

        /* BIT[7]: pll_clk_sel, BIT[6:2]: pll_nc, BIT[1:0]: pll_mc */
        pll_ctrl = ((pll_parameters->pll_nc << 2) | (pll_parameters->pll_mc << 0)) &
                    OV2735_PLL_CTRL_ENABLE;

        pll_outdiv = pll_parameters->pll_outdiv;

        ov2735_write(ov2735, OV2735_REG_PLL_CTRL, pll_ctrl, &ret);
        ov2735_write(ov2735, OV2735_REG_PLL_OUTDIV, pll_outdiv, &ret);

        return ret;
}

static int ov2735_set_framefmt(struct ov2735 *ov2735,
                               struct v4l2_subdev_state *state)
{
        const struct v4l2_mbus_framefmt *format;
        const struct v4l2_rect *crop;
        int ret = 0;

        format = v4l2_subdev_state_get_format(state, 0);
        crop = v4l2_subdev_state_get_crop(state, 0);

        ov2735_write(ov2735, OV2735_REG_V_START, crop->top, &ret);
        ov2735_write(ov2735, OV2735_REG_V_SIZE, format->height, &ret);
        ov2735_write(ov2735, OV2735_REG_MIPI_LINE_NUMBER, format->height, &ret);
        ov2735_write(ov2735, OV2735_REG_H_START, crop->left, &ret);
        /* OV2735_REG_H_SIZE: Image half horizontal size */
        ov2735_write(ov2735, OV2735_REG_H_SIZE, (format->width / 2), &ret);
        ov2735_write(ov2735, OV2735_REG_MIPI_COLOMN_NUMBER, format->width, &ret);

        return ret;
}

static int ov2735_enable_streams(struct v4l2_subdev *sd,
                                 struct v4l2_subdev_state *state, u32 pad,
                                 u64 streams_mask)
{
        struct ov2735 *ov2735 = to_ov2735(sd);
        int ret;

        ret = pm_runtime_resume_and_get(ov2735->dev);
        if (ret < 0)
                return ret;

        /* Apply pll settings */
        ret = ov2735_set_pll_ctrl(ov2735);
        if (ret) {
                dev_err(ov2735->dev, "failed to set frame format: %d\n", ret);
                goto err_rpm_put;
        }

        ret = ov2735_multi_reg_write(ov2735, ov2735_common_regs,
                                     ARRAY_SIZE(ov2735_common_regs), NULL);
        if (ret) {
                dev_err(ov2735->dev, "failed to write common registers\n");
                goto err_rpm_put;
        }

        /* Apply format settings */
        ret = ov2735_set_framefmt(ov2735, state);
        if (ret) {
                dev_err(ov2735->dev, "failed to set frame format: %d\n", ret);
                goto err_rpm_put;
        }

        /* Apply customized values from user */
        ret = __v4l2_ctrl_handler_setup(ov2735->sd.ctrl_handler);
        if (ret)
                goto err_rpm_put;

        ret = ov2735_write(ov2735, OV2735_REG_STREAM_CTRL,
                           OV2735_STREAM_CTRL_ON, NULL);
        if (ret)
                goto err_rpm_put;

        return 0;

err_rpm_put:
        pm_runtime_put(ov2735->dev);
        return ret;
}

static int ov2735_disable_streams(struct v4l2_subdev *sd,
                                  struct v4l2_subdev_state *state, u32 pad,
                                  u64 streams_mask)
{
        struct ov2735 *ov2735 = to_ov2735(sd);
        int ret;

        ret = ov2735_write(ov2735, OV2735_REG_STREAM_CTRL,
                           OV2735_STREAM_CTRL_OFF, NULL);
        if (ret)
                dev_err(ov2735->dev, "%s failed to set stream\n", __func__);

        pm_runtime_put(ov2735->dev);

        return ret;
}

static int ov2735_get_selection(struct v4l2_subdev *sd,
                                struct v4l2_subdev_state *sd_state,
                                struct v4l2_subdev_selection *sel)
{
        switch (sel->target) {
        case V4L2_SEL_TGT_CROP:
                sel->r = *v4l2_subdev_state_get_crop(sd_state, 0);
                return 0;
        case V4L2_SEL_TGT_NATIVE_SIZE:
                sel->r = ov2735_native_area;
                return 0;
        case V4L2_SEL_TGT_CROP_DEFAULT:
        case V4L2_SEL_TGT_CROP_BOUNDS:
                sel->r = ov2735_active_area;
                return 0;
        default:
                return -EINVAL;
        }
}

static int ov2735_enum_mbus_code(struct v4l2_subdev *sd,
                                 struct v4l2_subdev_state *sd_state,
                                 struct v4l2_subdev_mbus_code_enum *code)
{
        if (code->index)
                return -EINVAL;

        code->code = MEDIA_BUS_FMT_SGRBG10_1X10;

        return 0;
}

static int ov2735_enum_frame_size(struct v4l2_subdev *sd,
                                  struct v4l2_subdev_state *sd_state,
                                  struct v4l2_subdev_frame_size_enum *fse)
{
        if (fse->index >= ARRAY_SIZE(supported_modes))
                return -EINVAL;

        if (fse->code != MEDIA_BUS_FMT_SGRBG10_1X10)
                return -EINVAL;

        fse->min_width = supported_modes[fse->index].width;
        fse->max_width = fse->min_width;
        fse->min_height = supported_modes[fse->index].height;
        fse->max_height = fse->min_height;

        return 0;
}

static int ov2735_set_framing_limits(struct ov2735 *ov2735,
                                     const struct ov2735_mode *mode)
{
        u32 hblank, vblank_def;
        int ret;

        hblank = mode->hts_def - mode->width;
        ret = __v4l2_ctrl_modify_range(ov2735->hblank, hblank, hblank, 1,
                                       hblank);
        if (ret)
                return ret;

        vblank_def = mode->vts_def - mode->height;
        return __v4l2_ctrl_modify_range(ov2735->vblank, vblank_def,
                                        OV2735_FRAME_LENGTH_MAX - mode->height,
                                        1, vblank_def);
}

static int ov2735_set_pad_format(struct v4l2_subdev *sd,
                                 struct v4l2_subdev_state *sd_state,
                                 struct v4l2_subdev_format *fmt)
{
        struct v4l2_mbus_framefmt *format;
        const struct ov2735_mode *mode;
        struct v4l2_rect *crop;
        struct ov2735 *ov2735 = to_ov2735(sd);
        int ret;

        format = v4l2_subdev_state_get_format(sd_state, 0);

        mode = v4l2_find_nearest_size(supported_modes,
                                      ARRAY_SIZE(supported_modes),
                                      width, height,
                                      fmt->format.width, fmt->format.height);

        fmt->format.width = mode->width;
        fmt->format.height = mode->height;
        fmt->format.field = V4L2_FIELD_NONE;
        fmt->format.colorspace = V4L2_COLORSPACE_RAW;
        fmt->format.quantization = V4L2_QUANTIZATION_FULL_RANGE;
        fmt->format.xfer_func = V4L2_XFER_FUNC_NONE;

        if (fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
                ret = ov2735_set_framing_limits(ov2735, mode);
                if (ret)
                        return ret;
        }

        *format = fmt->format;

        /* Initialize crop rectangle */
        crop = v4l2_subdev_state_get_crop(sd_state, 0);
        *crop = mode->crop;

        return 0;
}

static int ov2735_init_state(struct v4l2_subdev *sd,
                             struct v4l2_subdev_state *state)
{
        struct v4l2_subdev_format fmt = {
                .which = V4L2_SUBDEV_FORMAT_TRY,
                .format = {
                        .code = MEDIA_BUS_FMT_SGRBG10_1X10,
                        .width = supported_modes[0].width,
                        .height = supported_modes[0].height,
                },
        };

        ov2735_set_pad_format(sd, state, &fmt);

        return 0;
}

static const struct v4l2_subdev_video_ops ov2735_video_ops = {
        .s_stream = v4l2_subdev_s_stream_helper,
};

static const struct v4l2_subdev_pad_ops ov2735_pad_ops = {
        .enum_mbus_code = ov2735_enum_mbus_code,
        .get_fmt = v4l2_subdev_get_fmt,
        .set_fmt = ov2735_set_pad_format,
        .get_selection = ov2735_get_selection,
        .enum_frame_size = ov2735_enum_frame_size,
        .enable_streams = ov2735_enable_streams,
        .disable_streams = ov2735_disable_streams,
};

static const struct v4l2_subdev_ops ov2735_subdev_ops = {
        .video = &ov2735_video_ops,
        .pad = &ov2735_pad_ops,
};

static const struct v4l2_subdev_internal_ops ov2735_internal_ops = {
        .init_state = ov2735_init_state,
};

static int ov2735_power_on(struct device *dev)
{
        struct v4l2_subdev *sd = dev_get_drvdata(dev);
        struct ov2735 *ov2735 = to_ov2735(sd);
        int ret;

        ret = regulator_bulk_enable(ARRAY_SIZE(ov2735_supply_name),
                                    ov2735->supplies);
        if (ret) {
                dev_err(ov2735->dev, "failed to enable regulators\n");
                return ret;
        }

        gpiod_set_value_cansleep(ov2735->enable_gpio, 1);
        /* T4: delay from PWDN pulling low to RSTB pulling high */
        fsleep(4 * USEC_PER_MSEC);

        ret = clk_prepare_enable(ov2735->xclk);
        if (ret) {
                dev_err(ov2735->dev, "failed to enable clock\n");
                goto err_regulator_off;
        }

        gpiod_set_value_cansleep(ov2735->reset_gpio, 0);
        /* T5: delay from RSTB pulling high to first I2C command */
        fsleep(5 * USEC_PER_MSEC);

        return 0;

err_regulator_off:
        regulator_bulk_disable(ARRAY_SIZE(ov2735_supply_name), ov2735->supplies);
        return ret;
}

static int ov2735_power_off(struct device *dev)
{
        struct v4l2_subdev *sd = dev_get_drvdata(dev);
        struct ov2735 *ov2735 = to_ov2735(sd);

        gpiod_set_value_cansleep(ov2735->enable_gpio, 0);
        clk_disable_unprepare(ov2735->xclk);
        gpiod_set_value_cansleep(ov2735->reset_gpio, 1);
        regulator_bulk_disable(ARRAY_SIZE(ov2735_supply_name), ov2735->supplies);

        return 0;
}

static int ov2735_get_regulators(struct ov2735 *ov2735)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(ov2735_supply_name); i++)
                ov2735->supplies[i].supply = ov2735_supply_name[i];

        return devm_regulator_bulk_get(ov2735->dev,
                                       ARRAY_SIZE(ov2735_supply_name),
                                       ov2735->supplies);
}

static int ov2735_identify_module(struct ov2735 *ov2735)
{
        u64 chip_id;
        int ret;

        ret = ov2735_read(ov2735, OV2735_REG_CHIPID, &chip_id, NULL);
        if (ret)
                return dev_err_probe(ov2735->dev, ret,
                                     "failed to read chip id %x\n",
                                     OV2735_CHIPID);

        if (chip_id != OV2735_CHIPID)
                return dev_err_probe(ov2735->dev, -EIO,
                                     "chip id mismatch: %x!=%llx\n",
                                     OV2735_CHIPID, chip_id);

        return 0;
}

static int ov2735_parse_endpoint(struct ov2735 *ov2735)
{
        struct v4l2_fwnode_endpoint bus_cfg = {
                .bus_type = V4L2_MBUS_CSI2_DPHY,
        };
        struct fwnode_handle *ep;
        unsigned long link_freq_bitmap;
        int ret;

        ep = fwnode_graph_get_next_endpoint(dev_fwnode(ov2735->dev), NULL);
        if (!ep)
                return dev_err_probe(ov2735->dev, -ENXIO,
                                     "Failed to get next endpoint\n");

        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 != 2) {
                ret = dev_err_probe(ov2735->dev, -EINVAL,
                                    "only 2 data lanes are supported\n");
                goto error_out;
        }

        ret = v4l2_link_freq_to_bitmap(ov2735->dev, bus_cfg.link_frequencies,
                                       bus_cfg.nr_of_link_frequencies,
                                       link_freq_menu_items,
                                       ARRAY_SIZE(link_freq_menu_items),
                                       &link_freq_bitmap);
        if (ret) {
                ret = dev_err_probe(ov2735->dev, -EINVAL,
                                    "only 420MHz frequency is available\n");
                goto error_out;
        }

        ov2735->link_freq_index = __ffs(link_freq_bitmap);

error_out:
        v4l2_fwnode_endpoint_free(&bus_cfg);

        return ret;
};

static int ov2735_probe(struct i2c_client *client)
{
        struct ov2735 *ov2735;
        unsigned int xclk_freq;
        int ret;

        ov2735 = devm_kzalloc(&client->dev, sizeof(*ov2735), GFP_KERNEL);
        if (!ov2735)
                return -ENOMEM;

        ov2735->dev = &client->dev;

        v4l2_i2c_subdev_init(&ov2735->sd, client, &ov2735_subdev_ops);
        ov2735->sd.internal_ops = &ov2735_internal_ops;

        ov2735->cci = devm_cci_regmap_init_i2c(client, 8);
        if (IS_ERR(ov2735->cci))
                return dev_err_probe(ov2735->dev, PTR_ERR(ov2735->cci),
                                     "failed to initialize CCI\n");

        /* Set Current page to 0 */
        ov2735->current_page = 0;

        ret = devm_mutex_init(ov2735->dev, &ov2735->page_lock);
        if (ret)
                return dev_err_probe(ov2735->dev, ret,
                                     "Failed to initialize lock\n");

        /* Get system clock (xvclk) */
        ov2735->xclk = devm_v4l2_sensor_clk_get(ov2735->dev, NULL);
        if (IS_ERR(ov2735->xclk))
                return dev_err_probe(ov2735->dev, PTR_ERR(ov2735->xclk),
                                     "failed to get xclk\n");

        xclk_freq = clk_get_rate(ov2735->xclk);
        if (xclk_freq != OV2735_XCLK_FREQ)
                return dev_err_probe(ov2735->dev, -EINVAL,
                                     "xclk frequency not supported: %u Hz\n",
                                     xclk_freq);

        ret = ov2735_get_regulators(ov2735);
        if (ret)
                return dev_err_probe(ov2735->dev, ret,
                                     "failed to get regulators\n");

        ret = ov2735_parse_endpoint(ov2735);
        if (ret)
                return dev_err_probe(ov2735->dev, ret,
                                     "failed to parse endpoint configuration\n");

        ov2735->reset_gpio = devm_gpiod_get_optional(ov2735->dev,
                                                     "reset", GPIOD_OUT_HIGH);
        if (IS_ERR(ov2735->reset_gpio))
                return dev_err_probe(ov2735->dev, PTR_ERR(ov2735->reset_gpio),
                                     "failed to get reset GPIO\n");

        ov2735->enable_gpio = devm_gpiod_get_optional(ov2735->dev,
                                                      "enable", GPIOD_OUT_LOW);
        if (IS_ERR(ov2735->enable_gpio))
                return dev_err_probe(ov2735->dev, PTR_ERR(ov2735->enable_gpio),
                                     "failed to get enable GPIO\n");

        ret = ov2735_power_on(ov2735->dev);
        if (ret)
                return ret;

        ret = ov2735_identify_module(ov2735);
        if (ret)
                goto error_power_off;

        ret = ov2735_init_controls(ov2735);
        if (ret)
                goto error_power_off;

        /* Initialize subdev */
        ov2735->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
        ov2735->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
        ov2735->pad.flags = MEDIA_PAD_FL_SOURCE;

        ret = media_entity_pads_init(&ov2735->sd.entity, 1, &ov2735->pad);
        if (ret) {
                dev_err_probe(ov2735->dev, ret, "failed to init entity pads\n");
                goto error_handler_free;
        }

        ov2735->sd.state_lock = ov2735->handler.lock;
        ret = v4l2_subdev_init_finalize(&ov2735->sd);
        if (ret) {
                dev_err_probe(ov2735->dev, ret, "subdev init error\n");
                goto error_media_entity;
        }

        ret = devm_pm_runtime_get_noresume(ov2735->dev);
        if (ret) {
                dev_err_probe(ov2735->dev, ret,
                              "failed to get runtime PM noresume\n");
                goto error_subdev_cleanup;
        }

        ret = devm_pm_runtime_set_active_enabled(ov2735->dev);
        if (ret) {
                dev_err_probe(ov2735->dev, ret,
                              "failed to set runtime PM active+enabled\n");
                goto error_subdev_cleanup;
        }

        ret = v4l2_async_register_subdev_sensor(&ov2735->sd);
        if (ret) {
                dev_err_probe(ov2735->dev, ret,
                              "failed to register ov2735 sub-device\n");
                goto error_subdev_cleanup;
        }

        return 0;

error_subdev_cleanup:
        v4l2_subdev_cleanup(&ov2735->sd);

error_media_entity:
        media_entity_cleanup(&ov2735->sd.entity);

error_handler_free:
        v4l2_ctrl_handler_free(ov2735->sd.ctrl_handler);

error_power_off:
        ov2735_power_off(ov2735->dev);

        return ret;
}

static void ov2735_remove(struct i2c_client *client)
{
        struct v4l2_subdev *sd = i2c_get_clientdata(client);
        struct ov2735 *ov2735 = to_ov2735(sd);

        v4l2_async_unregister_subdev(sd);
        v4l2_subdev_cleanup(&ov2735->sd);
        media_entity_cleanup(&sd->entity);
        v4l2_ctrl_handler_free(ov2735->sd.ctrl_handler);
}

static DEFINE_RUNTIME_DEV_PM_OPS(ov2735_pm_ops,
                                 ov2735_power_off, ov2735_power_on, NULL);

static const struct of_device_id ov2735_id[] = {
        { .compatible = "ovti,ov2735" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, ov2735_id);

static struct i2c_driver ov2735_driver = {
        .driver = {
                .name = "ov2735",
                .pm = pm_ptr(&ov2735_pm_ops),
                .of_match_table = ov2735_id,
        },
        .probe = ov2735_probe,
        .remove = ov2735_remove,
};
module_i2c_driver(ov2735_driver);

MODULE_DESCRIPTION("OV2735 Camera Sensor Driver");
MODULE_AUTHOR("Hardevsinh Palaniya <hardevsinh.palaniya@siliconsignals.io>");
MODULE_AUTHOR("Himanshu Bhavani <himanshu.bhavani@siliconsignals.io>");
MODULE_LICENSE("GPL");