root/drivers/media/i2c/ov7251.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Driver for the OV7251 camera sensor.
 *
 * Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
 * Copyright (c) 2017-2018, Linaro Ltd.
 */

#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-fwnode.h>
#include <media/v4l2-subdev.h>

#define OV7251_SC_MODE_SELECT           0x0100
#define OV7251_SC_MODE_SELECT_SW_STANDBY        0x0
#define OV7251_SC_MODE_SELECT_STREAMING         0x1

#define OV7251_CHIP_ID_HIGH             0x300a
#define OV7251_CHIP_ID_HIGH_BYTE        0x77
#define OV7251_CHIP_ID_LOW              0x300b
#define OV7251_CHIP_ID_LOW_BYTE         0x50
#define OV7251_SC_GP_IO_IN1             0x3029
#define OV7251_AEC_EXPO_0               0x3500
#define OV7251_AEC_EXPO_1               0x3501
#define OV7251_AEC_EXPO_2               0x3502
#define OV7251_AEC_AGC_ADJ_0            0x350a
#define OV7251_AEC_AGC_ADJ_1            0x350b
#define OV7251_TIMING_FORMAT1           0x3820
#define OV7251_TIMING_FORMAT1_VFLIP     BIT(2)
#define OV7251_TIMING_FORMAT2           0x3821
#define OV7251_TIMING_FORMAT2_MIRROR    BIT(2)
#define OV7251_PRE_ISP_00               0x5e00
#define OV7251_PRE_ISP_00_TEST_PATTERN  BIT(7)
#define OV7251_PLL1_PRE_DIV_REG         0x30b4
#define OV7251_PLL1_MULT_REG            0x30b3
#define OV7251_PLL1_DIVIDER_REG         0x30b1
#define OV7251_PLL1_PIX_DIV_REG         0x30b0
#define OV7251_PLL1_MIPI_DIV_REG        0x30b5
#define OV7251_PLL2_PRE_DIV_REG         0x3098
#define OV7251_PLL2_MULT_REG            0x3099
#define OV7251_PLL2_DIVIDER_REG         0x309d
#define OV7251_PLL2_SYS_DIV_REG         0x309a
#define OV7251_PLL2_ADC_DIV_REG         0x309b

#define OV7251_NATIVE_WIDTH             656
#define OV7251_NATIVE_HEIGHT            496
#define OV7251_ACTIVE_START_LEFT        4
#define OV7251_ACTIVE_START_TOP         4
#define OV7251_ACTIVE_WIDTH             648
#define OV7251_ACTIVE_HEIGHT            488

#define OV7251_FIXED_PPL                928
#define OV7251_TIMING_VTS_REG           0x380e
#define OV7251_TIMING_MIN_VTS           1
#define OV7251_TIMING_MAX_VTS           0xffff
#define OV7251_INTEGRATION_MARGIN       20

struct reg_value {
        u16 reg;
        u8 val;
};

struct ov7251_mode_info {
        u32 width;
        u32 height;
        u32 vts;
        const struct reg_value *data;
        u32 data_size;
        u32 pixel_clock;
        u32 link_freq;
        u16 exposure_max;
        u16 exposure_def;
        struct v4l2_fract timeperframe;
};

struct ov7251_pll1_cfg {
        unsigned int pre_div;
        unsigned int mult;
        unsigned int div;
        unsigned int pix_div;
        unsigned int mipi_div;
};

struct ov7251_pll2_cfg {
        unsigned int pre_div;
        unsigned int mult;
        unsigned int div;
        unsigned int sys_div;
        unsigned int adc_div;
};

/*
 * Rubbish ordering, but only PLL1 needs to have a separate configuration per
 * link frequency and the array member needs to be last.
 */
struct ov7251_pll_cfgs {
        const struct ov7251_pll2_cfg *pll2;
        const struct ov7251_pll1_cfg *pll1[];
};

enum xclk_rate {
        OV7251_19_2_MHZ,
        OV7251_24_MHZ,
        OV7251_NUM_SUPPORTED_RATES
};

enum supported_link_freqs {
        OV7251_LINK_FREQ_240_MHZ,
        OV7251_LINK_FREQ_319_2_MHZ,
        OV7251_NUM_SUPPORTED_LINK_FREQS
};

struct ov7251 {
        struct i2c_client *i2c_client;
        struct device *dev;
        struct v4l2_subdev sd;
        struct media_pad pad;
        struct v4l2_fwnode_endpoint ep;
        struct v4l2_mbus_framefmt fmt;
        struct v4l2_rect crop;
        struct clk *xclk;
        u32 xclk_freq;

        struct regulator *io_regulator;
        struct regulator *core_regulator;
        struct regulator *analog_regulator;

        const struct ov7251_pll_cfgs *pll_cfgs;
        enum supported_link_freqs link_freq_idx;
        const struct ov7251_mode_info *current_mode;

        struct v4l2_ctrl_handler ctrls;
        struct v4l2_ctrl *pixel_clock;
        struct v4l2_ctrl *link_freq;
        struct v4l2_ctrl *exposure;
        struct v4l2_ctrl *gain;
        struct v4l2_ctrl *hblank;
        struct v4l2_ctrl *vblank;

        /* Cached register values */
        u8 aec_pk_manual;
        u8 pre_isp_00;
        u8 timing_format1;
        u8 timing_format2;

        struct mutex lock; /* lock to protect power state, ctrls and mode */
        bool power_on;

        struct gpio_desc *enable_gpio;
};

static inline struct ov7251 *to_ov7251(struct v4l2_subdev *sd)
{
        return container_of(sd, struct ov7251, sd);
}

static const struct ov7251_pll1_cfg ov7251_pll1_cfg_19_2_mhz_240_mhz = {
        .pre_div = 0x03,
        .mult = 0x4b,
        .div = 0x01,
        .pix_div = 0x0a,
        .mipi_div = 0x05,
};

static const struct ov7251_pll1_cfg ov7251_pll1_cfg_19_2_mhz_319_2_mhz = {
        .pre_div = 0x01,
        .mult = 0x85,
        .div = 0x04,
        .pix_div = 0x0a,
        .mipi_div = 0x05,
};

static const struct ov7251_pll1_cfg ov7251_pll1_cfg_24_mhz_240_mhz = {
        .pre_div = 0x03,
        .mult = 0x64,
        .div = 0x01,
        .pix_div = 0x0a,
        .mipi_div = 0x05,
};

static const struct ov7251_pll1_cfg ov7251_pll1_cfg_24_mhz_319_2_mhz = {
        .pre_div = 0x05,
        .mult = 0x85,
        .div = 0x02,
        .pix_div = 0x0a,
        .mipi_div = 0x05,
};

static const struct ov7251_pll2_cfg ov7251_pll2_cfg_19_2_mhz = {
        .pre_div = 0x04,
        .mult = 0x32,
        .div = 0x00,
        .sys_div = 0x05,
        .adc_div = 0x04,
};

static const struct ov7251_pll2_cfg ov7251_pll2_cfg_24_mhz = {
        .pre_div = 0x04,
        .mult = 0x28,
        .div = 0x00,
        .sys_div = 0x05,
        .adc_div = 0x04,
};

static const struct ov7251_pll_cfgs ov7251_pll_cfgs_19_2_mhz = {
        .pll2 = &ov7251_pll2_cfg_19_2_mhz,
        .pll1 = {
                [OV7251_LINK_FREQ_240_MHZ] = &ov7251_pll1_cfg_19_2_mhz_240_mhz,
                [OV7251_LINK_FREQ_319_2_MHZ] = &ov7251_pll1_cfg_19_2_mhz_319_2_mhz,
        },
};

static const struct ov7251_pll_cfgs ov7251_pll_cfgs_24_mhz = {
        .pll2 = &ov7251_pll2_cfg_24_mhz,
        .pll1 = {
                [OV7251_LINK_FREQ_240_MHZ] = &ov7251_pll1_cfg_24_mhz_240_mhz,
                [OV7251_LINK_FREQ_319_2_MHZ] = &ov7251_pll1_cfg_24_mhz_319_2_mhz,
        },
};

static const struct ov7251_pll_cfgs *ov7251_pll_cfgs[] = {
        [OV7251_19_2_MHZ] = &ov7251_pll_cfgs_19_2_mhz,
        [OV7251_24_MHZ] = &ov7251_pll_cfgs_24_mhz,
};

static const struct reg_value ov7251_global_init_setting[] = {
        { 0x0103, 0x01 },
        { 0x303b, 0x02 },
};

static const struct reg_value ov7251_setting_vga_30fps[] = {
        { 0x3005, 0x00 },
        { 0x3012, 0xc0 },
        { 0x3013, 0xd2 },
        { 0x3014, 0x04 },
        { 0x3016, 0xf0 },
        { 0x3017, 0xf0 },
        { 0x3018, 0xf0 },
        { 0x301a, 0xf0 },
        { 0x301b, 0xf0 },
        { 0x301c, 0xf0 },
        { 0x3023, 0x05 },
        { 0x3037, 0xf0 },
        { 0x3106, 0xda },
        { 0x3503, 0x07 },
        { 0x3509, 0x10 },
        { 0x3600, 0x1c },
        { 0x3602, 0x62 },
        { 0x3620, 0xb7 },
        { 0x3622, 0x04 },
        { 0x3626, 0x21 },
        { 0x3627, 0x30 },
        { 0x3630, 0x44 },
        { 0x3631, 0x35 },
        { 0x3634, 0x60 },
        { 0x3636, 0x00 },
        { 0x3662, 0x01 },
        { 0x3663, 0x70 },
        { 0x3664, 0x50 },
        { 0x3666, 0x0a },
        { 0x3669, 0x1a },
        { 0x366a, 0x00 },
        { 0x366b, 0x50 },
        { 0x3673, 0x01 },
        { 0x3674, 0xff },
        { 0x3675, 0x03 },
        { 0x3705, 0xc1 },
        { 0x3709, 0x40 },
        { 0x373c, 0x08 },
        { 0x3742, 0x00 },
        { 0x3757, 0xb3 },
        { 0x3788, 0x00 },
        { 0x37a8, 0x01 },
        { 0x37a9, 0xc0 },
        { 0x3800, 0x00 },
        { 0x3801, 0x04 },
        { 0x3802, 0x00 },
        { 0x3803, 0x04 },
        { 0x3804, 0x02 },
        { 0x3805, 0x8b },
        { 0x3806, 0x01 },
        { 0x3807, 0xeb },
        { 0x3808, 0x02 }, /* width high */
        { 0x3809, 0x80 }, /* width low */
        { 0x380a, 0x01 }, /* height high */
        { 0x380b, 0xe0 }, /* height low */
        { 0x380c, 0x03 }, /* total horiz timing high */
        { 0x380d, 0xa0 }, /* total horiz timing low */
        { 0x380e, 0x06 }, /* total vertical timing high */
        { 0x380f, 0xbc }, /* total vertical timing low */
        { 0x3810, 0x00 },
        { 0x3811, 0x04 },
        { 0x3812, 0x00 },
        { 0x3813, 0x05 },
        { 0x3814, 0x11 },
        { 0x3815, 0x11 },
        { 0x3820, 0x40 },
        { 0x3821, 0x00 },
        { 0x382f, 0x0e },
        { 0x3832, 0x00 },
        { 0x3833, 0x05 },
        { 0x3834, 0x00 },
        { 0x3835, 0x0c },
        { 0x3837, 0x00 },
        { 0x3b80, 0x00 },
        { 0x3b81, 0xa5 },
        { 0x3b82, 0x10 },
        { 0x3b83, 0x00 },
        { 0x3b84, 0x08 },
        { 0x3b85, 0x00 },
        { 0x3b86, 0x01 },
        { 0x3b87, 0x00 },
        { 0x3b88, 0x00 },
        { 0x3b89, 0x00 },
        { 0x3b8a, 0x00 },
        { 0x3b8b, 0x05 },
        { 0x3b8c, 0x00 },
        { 0x3b8d, 0x00 },
        { 0x3b8e, 0x00 },
        { 0x3b8f, 0x1a },
        { 0x3b94, 0x05 },
        { 0x3b95, 0xf2 },
        { 0x3b96, 0x40 },
        { 0x3c00, 0x89 },
        { 0x3c01, 0x63 },
        { 0x3c02, 0x01 },
        { 0x3c03, 0x00 },
        { 0x3c04, 0x00 },
        { 0x3c05, 0x03 },
        { 0x3c06, 0x00 },
        { 0x3c07, 0x06 },
        { 0x3c0c, 0x01 },
        { 0x3c0d, 0xd0 },
        { 0x3c0e, 0x02 },
        { 0x3c0f, 0x0a },
        { 0x4001, 0x42 },
        { 0x4004, 0x04 },
        { 0x4005, 0x00 },
        { 0x404e, 0x01 },
        { 0x4300, 0xff },
        { 0x4301, 0x00 },
        { 0x4315, 0x00 },
        { 0x4501, 0x48 },
        { 0x4600, 0x00 },
        { 0x4601, 0x4e },
        { 0x4801, 0x0f },
        { 0x4806, 0x0f },
        { 0x4819, 0xaa },
        { 0x4823, 0x3e },
        { 0x4837, 0x19 },
        { 0x4a0d, 0x00 },
        { 0x4a47, 0x7f },
        { 0x4a49, 0xf0 },
        { 0x4a4b, 0x30 },
        { 0x5000, 0x85 },
        { 0x5001, 0x80 },
};

static const struct reg_value ov7251_setting_vga_60fps[] = {
        { 0x3005, 0x00 },
        { 0x3012, 0xc0 },
        { 0x3013, 0xd2 },
        { 0x3014, 0x04 },
        { 0x3016, 0x10 },
        { 0x3017, 0x00 },
        { 0x3018, 0x00 },
        { 0x301a, 0x00 },
        { 0x301b, 0x00 },
        { 0x301c, 0x00 },
        { 0x3023, 0x05 },
        { 0x3037, 0xf0 },
        { 0x3106, 0xda },
        { 0x3503, 0x07 },
        { 0x3509, 0x10 },
        { 0x3600, 0x1c },
        { 0x3602, 0x62 },
        { 0x3620, 0xb7 },
        { 0x3622, 0x04 },
        { 0x3626, 0x21 },
        { 0x3627, 0x30 },
        { 0x3630, 0x44 },
        { 0x3631, 0x35 },
        { 0x3634, 0x60 },
        { 0x3636, 0x00 },
        { 0x3662, 0x01 },
        { 0x3663, 0x70 },
        { 0x3664, 0x50 },
        { 0x3666, 0x0a },
        { 0x3669, 0x1a },
        { 0x366a, 0x00 },
        { 0x366b, 0x50 },
        { 0x3673, 0x01 },
        { 0x3674, 0xff },
        { 0x3675, 0x03 },
        { 0x3705, 0xc1 },
        { 0x3709, 0x40 },
        { 0x373c, 0x08 },
        { 0x3742, 0x00 },
        { 0x3757, 0xb3 },
        { 0x3788, 0x00 },
        { 0x37a8, 0x01 },
        { 0x37a9, 0xc0 },
        { 0x3800, 0x00 },
        { 0x3801, 0x04 },
        { 0x3802, 0x00 },
        { 0x3803, 0x04 },
        { 0x3804, 0x02 },
        { 0x3805, 0x8b },
        { 0x3806, 0x01 },
        { 0x3807, 0xeb },
        { 0x3808, 0x02 }, /* width high */
        { 0x3809, 0x80 }, /* width low */
        { 0x380a, 0x01 }, /* height high */
        { 0x380b, 0xe0 }, /* height low */
        { 0x380c, 0x03 }, /* total horiz timing high */
        { 0x380d, 0xa0 }, /* total horiz timing low */
        { 0x380e, 0x03 }, /* total vertical timing high */
        { 0x380f, 0x5c }, /* total vertical timing low */
        { 0x3810, 0x00 },
        { 0x3811, 0x04 },
        { 0x3812, 0x00 },
        { 0x3813, 0x05 },
        { 0x3814, 0x11 },
        { 0x3815, 0x11 },
        { 0x3820, 0x40 },
        { 0x3821, 0x00 },
        { 0x382f, 0x0e },
        { 0x3832, 0x00 },
        { 0x3833, 0x05 },
        { 0x3834, 0x00 },
        { 0x3835, 0x0c },
        { 0x3837, 0x00 },
        { 0x3b80, 0x00 },
        { 0x3b81, 0xa5 },
        { 0x3b82, 0x10 },
        { 0x3b83, 0x00 },
        { 0x3b84, 0x08 },
        { 0x3b85, 0x00 },
        { 0x3b86, 0x01 },
        { 0x3b87, 0x00 },
        { 0x3b88, 0x00 },
        { 0x3b89, 0x00 },
        { 0x3b8a, 0x00 },
        { 0x3b8b, 0x05 },
        { 0x3b8c, 0x00 },
        { 0x3b8d, 0x00 },
        { 0x3b8e, 0x00 },
        { 0x3b8f, 0x1a },
        { 0x3b94, 0x05 },
        { 0x3b95, 0xf2 },
        { 0x3b96, 0x40 },
        { 0x3c00, 0x89 },
        { 0x3c01, 0x63 },
        { 0x3c02, 0x01 },
        { 0x3c03, 0x00 },
        { 0x3c04, 0x00 },
        { 0x3c05, 0x03 },
        { 0x3c06, 0x00 },
        { 0x3c07, 0x06 },
        { 0x3c0c, 0x01 },
        { 0x3c0d, 0xd0 },
        { 0x3c0e, 0x02 },
        { 0x3c0f, 0x0a },
        { 0x4001, 0x42 },
        { 0x4004, 0x04 },
        { 0x4005, 0x00 },
        { 0x404e, 0x01 },
        { 0x4300, 0xff },
        { 0x4301, 0x00 },
        { 0x4315, 0x00 },
        { 0x4501, 0x48 },
        { 0x4600, 0x00 },
        { 0x4601, 0x4e },
        { 0x4801, 0x0f },
        { 0x4806, 0x0f },
        { 0x4819, 0xaa },
        { 0x4823, 0x3e },
        { 0x4837, 0x19 },
        { 0x4a0d, 0x00 },
        { 0x4a47, 0x7f },
        { 0x4a49, 0xf0 },
        { 0x4a4b, 0x30 },
        { 0x5000, 0x85 },
        { 0x5001, 0x80 },
};

static const struct reg_value ov7251_setting_vga_90fps[] = {
        { 0x3005, 0x00 },
        { 0x3012, 0xc0 },
        { 0x3013, 0xd2 },
        { 0x3014, 0x04 },
        { 0x3016, 0x10 },
        { 0x3017, 0x00 },
        { 0x3018, 0x00 },
        { 0x301a, 0x00 },
        { 0x301b, 0x00 },
        { 0x301c, 0x00 },
        { 0x3023, 0x05 },
        { 0x3037, 0xf0 },
        { 0x3106, 0xda },
        { 0x3503, 0x07 },
        { 0x3509, 0x10 },
        { 0x3600, 0x1c },
        { 0x3602, 0x62 },
        { 0x3620, 0xb7 },
        { 0x3622, 0x04 },
        { 0x3626, 0x21 },
        { 0x3627, 0x30 },
        { 0x3630, 0x44 },
        { 0x3631, 0x35 },
        { 0x3634, 0x60 },
        { 0x3636, 0x00 },
        { 0x3662, 0x01 },
        { 0x3663, 0x70 },
        { 0x3664, 0x50 },
        { 0x3666, 0x0a },
        { 0x3669, 0x1a },
        { 0x366a, 0x00 },
        { 0x366b, 0x50 },
        { 0x3673, 0x01 },
        { 0x3674, 0xff },
        { 0x3675, 0x03 },
        { 0x3705, 0xc1 },
        { 0x3709, 0x40 },
        { 0x373c, 0x08 },
        { 0x3742, 0x00 },
        { 0x3757, 0xb3 },
        { 0x3788, 0x00 },
        { 0x37a8, 0x01 },
        { 0x37a9, 0xc0 },
        { 0x3800, 0x00 },
        { 0x3801, 0x04 },
        { 0x3802, 0x00 },
        { 0x3803, 0x04 },
        { 0x3804, 0x02 },
        { 0x3805, 0x8b },
        { 0x3806, 0x01 },
        { 0x3807, 0xeb },
        { 0x3808, 0x02 }, /* width high */
        { 0x3809, 0x80 }, /* width low */
        { 0x380a, 0x01 }, /* height high */
        { 0x380b, 0xe0 }, /* height low */
        { 0x380c, 0x03 }, /* total horiz timing high */
        { 0x380d, 0xa0 }, /* total horiz timing low */
        { 0x380e, 0x02 }, /* total vertical timing high */
        { 0x380f, 0x3c }, /* total vertical timing low */
        { 0x3810, 0x00 },
        { 0x3811, 0x04 },
        { 0x3812, 0x00 },
        { 0x3813, 0x05 },
        { 0x3814, 0x11 },
        { 0x3815, 0x11 },
        { 0x3820, 0x40 },
        { 0x3821, 0x00 },
        { 0x382f, 0x0e },
        { 0x3832, 0x00 },
        { 0x3833, 0x05 },
        { 0x3834, 0x00 },
        { 0x3835, 0x0c },
        { 0x3837, 0x00 },
        { 0x3b80, 0x00 },
        { 0x3b81, 0xa5 },
        { 0x3b82, 0x10 },
        { 0x3b83, 0x00 },
        { 0x3b84, 0x08 },
        { 0x3b85, 0x00 },
        { 0x3b86, 0x01 },
        { 0x3b87, 0x00 },
        { 0x3b88, 0x00 },
        { 0x3b89, 0x00 },
        { 0x3b8a, 0x00 },
        { 0x3b8b, 0x05 },
        { 0x3b8c, 0x00 },
        { 0x3b8d, 0x00 },
        { 0x3b8e, 0x00 },
        { 0x3b8f, 0x1a },
        { 0x3b94, 0x05 },
        { 0x3b95, 0xf2 },
        { 0x3b96, 0x40 },
        { 0x3c00, 0x89 },
        { 0x3c01, 0x63 },
        { 0x3c02, 0x01 },
        { 0x3c03, 0x00 },
        { 0x3c04, 0x00 },
        { 0x3c05, 0x03 },
        { 0x3c06, 0x00 },
        { 0x3c07, 0x06 },
        { 0x3c0c, 0x01 },
        { 0x3c0d, 0xd0 },
        { 0x3c0e, 0x02 },
        { 0x3c0f, 0x0a },
        { 0x4001, 0x42 },
        { 0x4004, 0x04 },
        { 0x4005, 0x00 },
        { 0x404e, 0x01 },
        { 0x4300, 0xff },
        { 0x4301, 0x00 },
        { 0x4315, 0x00 },
        { 0x4501, 0x48 },
        { 0x4600, 0x00 },
        { 0x4601, 0x4e },
        { 0x4801, 0x0f },
        { 0x4806, 0x0f },
        { 0x4819, 0xaa },
        { 0x4823, 0x3e },
        { 0x4837, 0x19 },
        { 0x4a0d, 0x00 },
        { 0x4a47, 0x7f },
        { 0x4a49, 0xf0 },
        { 0x4a4b, 0x30 },
        { 0x5000, 0x85 },
        { 0x5001, 0x80 },
};

static const unsigned long supported_xclk_rates[] = {
        [OV7251_19_2_MHZ] = 19200000,
        [OV7251_24_MHZ] = 24000000,
};

static const s64 link_freq[] = {
        [OV7251_LINK_FREQ_240_MHZ] = 240000000,
        [OV7251_LINK_FREQ_319_2_MHZ] = 319200000,
};

static const s64 pixel_rates[] = {
        [OV7251_LINK_FREQ_240_MHZ] = 48000000,
        [OV7251_LINK_FREQ_319_2_MHZ] = 63840000,
};

static const struct ov7251_mode_info ov7251_mode_info_data[] = {
        {
                .width = 640,
                .height = 480,
                .vts = 1724,
                .data = ov7251_setting_vga_30fps,
                .data_size = ARRAY_SIZE(ov7251_setting_vga_30fps),
                .exposure_max = 1704,
                .exposure_def = 504,
                .timeperframe = {
                        .numerator = 100,
                        .denominator = 3000
                }
        },
        {
                .width = 640,
                .height = 480,
                .vts = 860,
                .data = ov7251_setting_vga_60fps,
                .data_size = ARRAY_SIZE(ov7251_setting_vga_60fps),
                .exposure_max = 840,
                .exposure_def = 504,
                .timeperframe = {
                        .numerator = 100,
                        .denominator = 6014
                }
        },
        {
                .width = 640,
                .height = 480,
                .vts = 572,
                .data = ov7251_setting_vga_90fps,
                .data_size = ARRAY_SIZE(ov7251_setting_vga_90fps),
                .exposure_max = 552,
                .exposure_def = 504,
                .timeperframe = {
                        .numerator = 100,
                        .denominator = 9043
                }
        },
};

static int ov7251_regulators_enable(struct ov7251 *ov7251)
{
        int ret;

        /* OV7251 power up sequence requires core regulator
         * to be enabled not earlier than io regulator
         */

        ret = regulator_enable(ov7251->io_regulator);
        if (ret < 0) {
                dev_err(ov7251->dev, "set io voltage failed\n");
                return ret;
        }

        ret = regulator_enable(ov7251->analog_regulator);
        if (ret) {
                dev_err(ov7251->dev, "set analog voltage failed\n");
                goto err_disable_io;
        }

        ret = regulator_enable(ov7251->core_regulator);
        if (ret) {
                dev_err(ov7251->dev, "set core voltage failed\n");
                goto err_disable_analog;
        }

        return 0;

err_disable_analog:
        regulator_disable(ov7251->analog_regulator);

err_disable_io:
        regulator_disable(ov7251->io_regulator);

        return ret;
}

static void ov7251_regulators_disable(struct ov7251 *ov7251)
{
        int ret;

        ret = regulator_disable(ov7251->core_regulator);
        if (ret < 0)
                dev_err(ov7251->dev, "core regulator disable failed\n");

        ret = regulator_disable(ov7251->analog_regulator);
        if (ret < 0)
                dev_err(ov7251->dev, "analog regulator disable failed\n");

        ret = regulator_disable(ov7251->io_regulator);
        if (ret < 0)
                dev_err(ov7251->dev, "io regulator disable failed\n");
}

static int ov7251_write_reg(struct ov7251 *ov7251, u16 reg, u8 val)
{
        u8 regbuf[3];
        int ret;

        regbuf[0] = reg >> 8;
        regbuf[1] = reg & 0xff;
        regbuf[2] = val;

        ret = i2c_master_send(ov7251->i2c_client, regbuf, 3);
        if (ret < 0) {
                dev_err(ov7251->dev, "%s: write reg error %d: reg=%x, val=%x\n",
                        __func__, ret, reg, val);
                return ret;
        }

        return 0;
}

static int ov7251_write_seq_regs(struct ov7251 *ov7251, u16 reg, u8 *val,
                                 u8 num)
{
        u8 regbuf[5];
        u8 nregbuf = sizeof(reg) + num * sizeof(*val);
        int ret = 0;

        if (nregbuf > sizeof(regbuf))
                return -EINVAL;

        regbuf[0] = reg >> 8;
        regbuf[1] = reg & 0xff;

        memcpy(regbuf + 2, val, num);

        ret = i2c_master_send(ov7251->i2c_client, regbuf, nregbuf);
        if (ret < 0) {
                dev_err(ov7251->dev,
                        "%s: write seq regs error %d: first reg=%x\n",
                        __func__, ret, reg);
                return ret;
        }

        return 0;
}

static int ov7251_read_reg(struct ov7251 *ov7251, u16 reg, u8 *val)
{
        u8 regbuf[2];
        int ret;

        regbuf[0] = reg >> 8;
        regbuf[1] = reg & 0xff;

        ret = i2c_master_send(ov7251->i2c_client, regbuf, 2);
        if (ret < 0) {
                dev_err(ov7251->dev, "%s: write reg error %d: reg=%x\n",
                        __func__, ret, reg);
                return ret;
        }

        ret = i2c_master_recv(ov7251->i2c_client, val, 1);
        if (ret < 0) {
                dev_err(ov7251->dev, "%s: read reg error %d: reg=%x\n",
                        __func__, ret, reg);
                return ret;
        }

        return 0;
}

static int ov7251_pll_configure(struct ov7251 *ov7251)
{
        const struct ov7251_pll_cfgs *configs;
        int ret;

        configs = ov7251->pll_cfgs;

        ret = ov7251_write_reg(ov7251, OV7251_PLL1_PRE_DIV_REG,
                               configs->pll1[ov7251->link_freq_idx]->pre_div);
        if (ret < 0)
                return ret;

        ret = ov7251_write_reg(ov7251, OV7251_PLL1_MULT_REG,
                               configs->pll1[ov7251->link_freq_idx]->mult);
        if (ret < 0)
                return ret;
        ret = ov7251_write_reg(ov7251, OV7251_PLL1_DIVIDER_REG,
                               configs->pll1[ov7251->link_freq_idx]->div);
        if (ret < 0)
                return ret;

        ret = ov7251_write_reg(ov7251, OV7251_PLL1_PIX_DIV_REG,
                               configs->pll1[ov7251->link_freq_idx]->pix_div);
        if (ret < 0)
                return ret;

        ret = ov7251_write_reg(ov7251, OV7251_PLL1_MIPI_DIV_REG,
                               configs->pll1[ov7251->link_freq_idx]->mipi_div);
        if (ret < 0)
                return ret;

        ret = ov7251_write_reg(ov7251, OV7251_PLL2_PRE_DIV_REG,
                               configs->pll2->pre_div);
        if (ret < 0)
                return ret;

        ret = ov7251_write_reg(ov7251, OV7251_PLL2_MULT_REG,
                               configs->pll2->mult);
        if (ret < 0)
                return ret;

        ret = ov7251_write_reg(ov7251, OV7251_PLL2_DIVIDER_REG,
                               configs->pll2->div);
        if (ret < 0)
                return ret;

        ret = ov7251_write_reg(ov7251, OV7251_PLL2_SYS_DIV_REG,
                               configs->pll2->sys_div);
        if (ret < 0)
                return ret;

        ret = ov7251_write_reg(ov7251, OV7251_PLL2_ADC_DIV_REG,
                               configs->pll2->adc_div);

        return ret;
}

static int ov7251_set_exposure(struct ov7251 *ov7251, s32 exposure)
{
        u16 reg;
        u8 val[3];

        reg = OV7251_AEC_EXPO_0;
        val[0] = (exposure & 0xf000) >> 12; /* goes to OV7251_AEC_EXPO_0 */
        val[1] = (exposure & 0x0ff0) >> 4;  /* goes to OV7251_AEC_EXPO_1 */
        val[2] = (exposure & 0x000f) << 4;  /* goes to OV7251_AEC_EXPO_2 */

        return ov7251_write_seq_regs(ov7251, reg, val, 3);
}

static int ov7251_set_gain(struct ov7251 *ov7251, s32 gain)
{
        u16 reg;
        u8 val[2];

        reg = OV7251_AEC_AGC_ADJ_0;
        val[0] = (gain & 0x0300) >> 8; /* goes to OV7251_AEC_AGC_ADJ_0 */
        val[1] = gain & 0xff;          /* goes to OV7251_AEC_AGC_ADJ_1 */

        return ov7251_write_seq_regs(ov7251, reg, val, 2);
}

static int ov7251_set_register_array(struct ov7251 *ov7251,
                                     const struct reg_value *settings,
                                     unsigned int num_settings)
{
        unsigned int i;
        int ret;

        for (i = 0; i < num_settings; ++i, ++settings) {
                ret = ov7251_write_reg(ov7251, settings->reg, settings->val);
                if (ret < 0)
                        return ret;
        }

        return 0;
}

static int ov7251_set_power_on(struct device *dev)
{
        struct i2c_client *client = container_of(dev, struct i2c_client, dev);
        struct v4l2_subdev *sd = i2c_get_clientdata(client);
        struct ov7251 *ov7251 = to_ov7251(sd);
        int ret;
        u32 wait_us;

        ret = ov7251_regulators_enable(ov7251);
        if (ret < 0)
                return ret;

        ret = clk_prepare_enable(ov7251->xclk);
        if (ret < 0) {
                dev_err(ov7251->dev, "clk prepare enable failed\n");
                ov7251_regulators_disable(ov7251);
                return ret;
        }

        usleep_range(1000, 1100);

        gpiod_set_value_cansleep(ov7251->enable_gpio, 1);

        /* wait at least 65536 external clock cycles */
        wait_us = DIV_ROUND_UP(65536 * 1000,
                               DIV_ROUND_UP(ov7251->xclk_freq, 1000));
        usleep_range(wait_us, wait_us + 1000);

        ret = ov7251_set_register_array(ov7251,
                                        ov7251_global_init_setting,
                                        ARRAY_SIZE(ov7251_global_init_setting));
        if (ret < 0) {
                dev_err(ov7251->dev, "error during global init\n");
                gpiod_set_value_cansleep(ov7251->enable_gpio, 0);
                clk_disable_unprepare(ov7251->xclk);
                ov7251_regulators_disable(ov7251);
                return ret;
        }

        return ret;
}

static int ov7251_set_power_off(struct device *dev)
{
        struct i2c_client *client = container_of(dev, struct i2c_client, dev);
        struct v4l2_subdev *sd = i2c_get_clientdata(client);
        struct ov7251 *ov7251 = to_ov7251(sd);

        clk_disable_unprepare(ov7251->xclk);
        gpiod_set_value_cansleep(ov7251->enable_gpio, 0);
        ov7251_regulators_disable(ov7251);

        return 0;
}

static int ov7251_set_hflip(struct ov7251 *ov7251, s32 value)
{
        u8 val = ov7251->timing_format2;
        int ret;

        if (value)
                val |= OV7251_TIMING_FORMAT2_MIRROR;
        else
                val &= ~OV7251_TIMING_FORMAT2_MIRROR;

        ret = ov7251_write_reg(ov7251, OV7251_TIMING_FORMAT2, val);
        if (!ret)
                ov7251->timing_format2 = val;

        return ret;
}

static int ov7251_set_vflip(struct ov7251 *ov7251, s32 value)
{
        u8 val = ov7251->timing_format1;
        int ret;

        if (value)
                val |= OV7251_TIMING_FORMAT1_VFLIP;
        else
                val &= ~OV7251_TIMING_FORMAT1_VFLIP;

        ret = ov7251_write_reg(ov7251, OV7251_TIMING_FORMAT1, val);
        if (!ret)
                ov7251->timing_format1 = val;

        return ret;
}

static int ov7251_set_test_pattern(struct ov7251 *ov7251, s32 value)
{
        u8 val = ov7251->pre_isp_00;
        int ret;

        if (value)
                val |= OV7251_PRE_ISP_00_TEST_PATTERN;
        else
                val &= ~OV7251_PRE_ISP_00_TEST_PATTERN;

        ret = ov7251_write_reg(ov7251, OV7251_PRE_ISP_00, val);
        if (!ret)
                ov7251->pre_isp_00 = val;

        return ret;
}

static const char * const ov7251_test_pattern_menu[] = {
        "Disabled",
        "Vertical Pattern Bars",
};

static int ov7251_vts_configure(struct ov7251 *ov7251, s32 vblank)
{
        u8 vts[2];

        vts[0] = ((ov7251->current_mode->height + vblank) & 0xff00) >> 8;
        vts[1] = ((ov7251->current_mode->height + vblank) & 0x00ff);

        return ov7251_write_seq_regs(ov7251, OV7251_TIMING_VTS_REG, vts, 2);
}

static int ov7251_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct ov7251 *ov7251 = container_of(ctrl->handler,
                                             struct ov7251, ctrls);
        int ret;

        /* If VBLANK is altered we need to update exposure to compensate */
        if (ctrl->id == V4L2_CID_VBLANK) {
                int exposure_max;

                exposure_max = ov7251->current_mode->height + ctrl->val -
                               OV7251_INTEGRATION_MARGIN;
                __v4l2_ctrl_modify_range(ov7251->exposure,
                                         ov7251->exposure->minimum,
                                         exposure_max,
                                         ov7251->exposure->step,
                                         min(ov7251->exposure->val,
                                             exposure_max));
        }

        /* v4l2_ctrl_lock() locks our mutex */

        if (!pm_runtime_get_if_in_use(ov7251->dev))
                return 0;

        switch (ctrl->id) {
        case V4L2_CID_EXPOSURE:
                ret = ov7251_set_exposure(ov7251, ctrl->val);
                break;
        case V4L2_CID_GAIN:
                ret = ov7251_set_gain(ov7251, ctrl->val);
                break;
        case V4L2_CID_TEST_PATTERN:
                ret = ov7251_set_test_pattern(ov7251, ctrl->val);
                break;
        case V4L2_CID_HFLIP:
                ret = ov7251_set_hflip(ov7251, ctrl->val);
                break;
        case V4L2_CID_VFLIP:
                ret = ov7251_set_vflip(ov7251, ctrl->val);
                break;
        case V4L2_CID_VBLANK:
                ret = ov7251_vts_configure(ov7251, ctrl->val);
                break;
        default:
                ret = -EINVAL;
                break;
        }

        pm_runtime_put(ov7251->dev);

        return ret;
}

static const struct v4l2_ctrl_ops ov7251_ctrl_ops = {
        .s_ctrl = ov7251_s_ctrl,
};

static int ov7251_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 = MEDIA_BUS_FMT_Y10_1X10;

        return 0;
}

static int ov7251_enum_frame_size(struct v4l2_subdev *subdev,
                                  struct v4l2_subdev_state *sd_state,
                                  struct v4l2_subdev_frame_size_enum *fse)
{
        if (fse->code != MEDIA_BUS_FMT_Y10_1X10)
                return -EINVAL;

        if (fse->index >= ARRAY_SIZE(ov7251_mode_info_data))
                return -EINVAL;

        fse->min_width = ov7251_mode_info_data[fse->index].width;
        fse->max_width = ov7251_mode_info_data[fse->index].width;
        fse->min_height = ov7251_mode_info_data[fse->index].height;
        fse->max_height = ov7251_mode_info_data[fse->index].height;

        return 0;
}

static int ov7251_enum_frame_ival(struct v4l2_subdev *subdev,
                                  struct v4l2_subdev_state *sd_state,
                                  struct v4l2_subdev_frame_interval_enum *fie)
{
        unsigned int index = fie->index;
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(ov7251_mode_info_data); i++) {
                if (fie->width != ov7251_mode_info_data[i].width ||
                    fie->height != ov7251_mode_info_data[i].height)
                        continue;

                if (index-- == 0) {
                        fie->interval = ov7251_mode_info_data[i].timeperframe;
                        return 0;
                }
        }

        return -EINVAL;
}

static struct v4l2_mbus_framefmt *
__ov7251_get_pad_format(struct ov7251 *ov7251,
                        struct v4l2_subdev_state *sd_state,
                        unsigned int pad,
                        enum v4l2_subdev_format_whence which)
{
        switch (which) {
        case V4L2_SUBDEV_FORMAT_TRY:
                return v4l2_subdev_state_get_format(sd_state, pad);
        case V4L2_SUBDEV_FORMAT_ACTIVE:
                return &ov7251->fmt;
        default:
                return NULL;
        }
}

static int ov7251_get_format(struct v4l2_subdev *sd,
                             struct v4l2_subdev_state *sd_state,
                             struct v4l2_subdev_format *format)
{
        struct ov7251 *ov7251 = to_ov7251(sd);

        mutex_lock(&ov7251->lock);
        format->format = *__ov7251_get_pad_format(ov7251, sd_state,
                                                  format->pad,
                                                  format->which);
        mutex_unlock(&ov7251->lock);

        return 0;
}

static struct v4l2_rect *
__ov7251_get_pad_crop(struct ov7251 *ov7251,
                      struct v4l2_subdev_state *sd_state,
                      unsigned int pad, enum v4l2_subdev_format_whence which)
{
        switch (which) {
        case V4L2_SUBDEV_FORMAT_TRY:
                return v4l2_subdev_state_get_crop(sd_state, pad);
        case V4L2_SUBDEV_FORMAT_ACTIVE:
                return &ov7251->crop;
        default:
                return NULL;
        }
}

static inline u32 avg_fps(const struct v4l2_fract *t)
{
        return (t->denominator + (t->numerator >> 1)) / t->numerator;
}

static const struct ov7251_mode_info *
ov7251_find_mode_by_ival(struct ov7251 *ov7251, struct v4l2_fract *timeperframe)
{
        const struct ov7251_mode_info *mode = ov7251->current_mode;
        unsigned int fps_req = avg_fps(timeperframe);
        unsigned int max_dist_match = (unsigned int) -1;
        unsigned int i, n = 0;

        for (i = 0; i < ARRAY_SIZE(ov7251_mode_info_data); i++) {
                unsigned int dist;
                unsigned int fps_tmp;

                if (mode->width != ov7251_mode_info_data[i].width ||
                    mode->height != ov7251_mode_info_data[i].height)
                        continue;

                fps_tmp = avg_fps(&ov7251_mode_info_data[i].timeperframe);

                dist = abs(fps_req - fps_tmp);

                if (dist < max_dist_match) {
                        n = i;
                        max_dist_match = dist;
                }
        }

        return &ov7251_mode_info_data[n];
}

static int ov7251_set_format(struct v4l2_subdev *sd,
                             struct v4l2_subdev_state *sd_state,
                             struct v4l2_subdev_format *format)
{
        struct ov7251 *ov7251 = to_ov7251(sd);
        struct v4l2_mbus_framefmt *__format;
        int vblank_max, vblank_def;
        struct v4l2_rect *__crop;
        const struct ov7251_mode_info *new_mode;
        int ret = 0;

        mutex_lock(&ov7251->lock);

        __crop = __ov7251_get_pad_crop(ov7251, sd_state, format->pad,
                                       format->which);

        new_mode = v4l2_find_nearest_size(ov7251_mode_info_data,
                                ARRAY_SIZE(ov7251_mode_info_data),
                                width, height,
                                format->format.width, format->format.height);

        __crop->width = new_mode->width;
        __crop->height = new_mode->height;

        if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
                ret = __v4l2_ctrl_modify_range(ov7251->exposure,
                                               1, new_mode->exposure_max,
                                               1, new_mode->exposure_def);
                if (ret < 0)
                        goto exit;

                ret = __v4l2_ctrl_s_ctrl(ov7251->exposure,
                                         new_mode->exposure_def);
                if (ret < 0)
                        goto exit;

                ret = __v4l2_ctrl_s_ctrl(ov7251->gain, 16);
                if (ret < 0)
                        goto exit;

                vblank_max = OV7251_TIMING_MAX_VTS - new_mode->height;
                vblank_def = new_mode->vts - new_mode->height;
                ret = __v4l2_ctrl_modify_range(ov7251->vblank,
                                               OV7251_TIMING_MIN_VTS,
                                               vblank_max, 1, vblank_def);
                if (ret < 0)
                        goto exit;

                ov7251->current_mode = new_mode;
        }

        __format = __ov7251_get_pad_format(ov7251, sd_state, format->pad,
                                           format->which);
        __format->width = __crop->width;
        __format->height = __crop->height;
        __format->code = MEDIA_BUS_FMT_Y10_1X10;
        __format->field = V4L2_FIELD_NONE;
        __format->colorspace = V4L2_COLORSPACE_SRGB;
        __format->ycbcr_enc = V4L2_MAP_YCBCR_ENC_DEFAULT(__format->colorspace);
        __format->quantization = V4L2_MAP_QUANTIZATION_DEFAULT(true,
                                __format->colorspace, __format->ycbcr_enc);
        __format->xfer_func = V4L2_MAP_XFER_FUNC_DEFAULT(__format->colorspace);

        format->format = *__format;

exit:
        mutex_unlock(&ov7251->lock);

        return ret;
}

static int ov7251_init_state(struct v4l2_subdev *subdev,
                             struct v4l2_subdev_state *sd_state)
{
        struct v4l2_subdev_format fmt = {
                .which = sd_state ? V4L2_SUBDEV_FORMAT_TRY
                : V4L2_SUBDEV_FORMAT_ACTIVE,
                .format = {
                        .width = 640,
                        .height = 480
                }
        };

        ov7251_set_format(subdev, sd_state, &fmt);

        return 0;
}

static int ov7251_get_selection(struct v4l2_subdev *sd,
                                struct v4l2_subdev_state *sd_state,
                                struct v4l2_subdev_selection *sel)
{
        struct ov7251 *ov7251 = to_ov7251(sd);

        switch (sel->target) {
        case V4L2_SEL_TGT_CROP_DEFAULT:
        case V4L2_SEL_TGT_CROP:
        mutex_lock(&ov7251->lock);
                sel->r = *__ov7251_get_pad_crop(ov7251, sd_state, sel->pad,
                                                sel->which);
                mutex_unlock(&ov7251->lock);
                break;
        case V4L2_SEL_TGT_NATIVE_SIZE:
                sel->r.top = 0;
                sel->r.left = 0;
                sel->r.width = OV7251_NATIVE_WIDTH;
                sel->r.height = OV7251_NATIVE_HEIGHT;
                break;
        case V4L2_SEL_TGT_CROP_BOUNDS:
                sel->r.top = OV7251_ACTIVE_START_TOP;
                sel->r.left = OV7251_ACTIVE_START_LEFT;
                sel->r.width = OV7251_ACTIVE_WIDTH;
                sel->r.height = OV7251_ACTIVE_HEIGHT;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int ov7251_s_stream(struct v4l2_subdev *subdev, int enable)
{
        struct ov7251 *ov7251 = to_ov7251(subdev);
        int ret;

        mutex_lock(&ov7251->lock);

        if (enable) {
                ret = pm_runtime_resume_and_get(ov7251->dev);
                if (ret) {
                        mutex_unlock(&ov7251->lock);
                        return ret;
                }

                ret = ov7251_pll_configure(ov7251);
                if (ret) {
                        dev_err(ov7251->dev, "error configuring PLLs\n");
                        goto err_power_down;
                }

                ret = ov7251_set_register_array(ov7251,
                                        ov7251->current_mode->data,
                                        ov7251->current_mode->data_size);
                if (ret < 0) {
                        dev_err(ov7251->dev, "could not set mode %dx%d\n",
                                ov7251->current_mode->width,
                                ov7251->current_mode->height);
                        goto err_power_down;
                }
                ret = __v4l2_ctrl_handler_setup(&ov7251->ctrls);
                if (ret < 0) {
                        dev_err(ov7251->dev, "could not sync v4l2 controls\n");
                        goto err_power_down;
                }
                ret = ov7251_write_reg(ov7251, OV7251_SC_MODE_SELECT,
                                       OV7251_SC_MODE_SELECT_STREAMING);
                if (ret)
                        goto err_power_down;
        } else {
                ret = ov7251_write_reg(ov7251, OV7251_SC_MODE_SELECT,
                                       OV7251_SC_MODE_SELECT_SW_STANDBY);
                pm_runtime_put(ov7251->dev);
        }

        mutex_unlock(&ov7251->lock);
        return ret;

err_power_down:
        pm_runtime_put(ov7251->dev);
        mutex_unlock(&ov7251->lock);
        return ret;
}

static int ov7251_get_frame_interval(struct v4l2_subdev *subdev,
                                     struct v4l2_subdev_state *sd_state,
                                     struct v4l2_subdev_frame_interval *fi)
{
        struct ov7251 *ov7251 = to_ov7251(subdev);

        /*
         * FIXME: Implement support for V4L2_SUBDEV_FORMAT_TRY, using the V4L2
         * subdev active state API.
         */
        if (fi->which != V4L2_SUBDEV_FORMAT_ACTIVE)
                return -EINVAL;

        mutex_lock(&ov7251->lock);
        fi->interval = ov7251->current_mode->timeperframe;
        mutex_unlock(&ov7251->lock);

        return 0;
}

static int ov7251_set_frame_interval(struct v4l2_subdev *subdev,
                                     struct v4l2_subdev_state *sd_state,
                                     struct v4l2_subdev_frame_interval *fi)
{
        struct ov7251 *ov7251 = to_ov7251(subdev);
        const struct ov7251_mode_info *new_mode;
        int ret = 0;

        /*
         * FIXME: Implement support for V4L2_SUBDEV_FORMAT_TRY, using the V4L2
         * subdev active state API.
         */
        if (fi->which != V4L2_SUBDEV_FORMAT_ACTIVE)
                return -EINVAL;

        mutex_lock(&ov7251->lock);
        new_mode = ov7251_find_mode_by_ival(ov7251, &fi->interval);

        if (new_mode != ov7251->current_mode) {
                ret = __v4l2_ctrl_modify_range(ov7251->exposure,
                                               1, new_mode->exposure_max,
                                               1, new_mode->exposure_def);
                if (ret < 0)
                        goto exit;

                ret = __v4l2_ctrl_s_ctrl(ov7251->exposure,
                                         new_mode->exposure_def);
                if (ret < 0)
                        goto exit;

                ret = __v4l2_ctrl_s_ctrl(ov7251->gain, 16);
                if (ret < 0)
                        goto exit;

                ov7251->current_mode = new_mode;
        }

        fi->interval = ov7251->current_mode->timeperframe;

exit:
        mutex_unlock(&ov7251->lock);

        return ret;
}

static const struct v4l2_subdev_video_ops ov7251_video_ops = {
        .s_stream = ov7251_s_stream,
};

static const struct v4l2_subdev_pad_ops ov7251_subdev_pad_ops = {
        .enum_mbus_code = ov7251_enum_mbus_code,
        .enum_frame_size = ov7251_enum_frame_size,
        .enum_frame_interval = ov7251_enum_frame_ival,
        .get_fmt = ov7251_get_format,
        .set_fmt = ov7251_set_format,
        .get_selection = ov7251_get_selection,
        .get_frame_interval = ov7251_get_frame_interval,
        .set_frame_interval = ov7251_set_frame_interval,
};

static const struct v4l2_subdev_ops ov7251_subdev_ops = {
        .video = &ov7251_video_ops,
        .pad = &ov7251_subdev_pad_ops,
};

static const struct v4l2_subdev_internal_ops ov7251_internal_ops = {
        .init_state = ov7251_init_state,
};

static int ov7251_check_hwcfg(struct ov7251 *ov7251)
{
        struct fwnode_handle *fwnode = dev_fwnode(ov7251->dev);
        struct v4l2_fwnode_endpoint bus_cfg = {
                .bus_type = V4L2_MBUS_CSI2_DPHY,
        };
        struct fwnode_handle *endpoint;
        unsigned int i, j;
        int ret;

        /*
         * Sometimes the fwnode graph is initialized by the bridge driver
         * Bridge drivers doing this may also add GPIO mappings, wait for this.
         */
        endpoint = fwnode_graph_get_next_endpoint(fwnode, NULL);
        if (!endpoint)
                return dev_err_probe(ov7251->dev, -EPROBE_DEFER,
                                     "waiting for fwnode graph endpoint\n");

        ret = v4l2_fwnode_endpoint_alloc_parse(endpoint, &bus_cfg);
        fwnode_handle_put(endpoint);
        if (ret)
                return dev_err_probe(ov7251->dev, ret,
                                     "parsing endpoint node failed\n");

        if (!bus_cfg.nr_of_link_frequencies) {
                ret = dev_err_probe(ov7251->dev, -EINVAL,
                                    "no link frequencies defined\n");
                goto out_free_bus_cfg;
        }

        for (i = 0; i < bus_cfg.nr_of_link_frequencies; i++) {
                for (j = 0; j < ARRAY_SIZE(link_freq); j++)
                        if (bus_cfg.link_frequencies[i] == link_freq[j])
                                break;

                if (j < ARRAY_SIZE(link_freq))
                        break;
        }

        if (i == bus_cfg.nr_of_link_frequencies) {
                ret = dev_err_probe(ov7251->dev, -EINVAL,
                                    "no supported link freq found\n");
                goto out_free_bus_cfg;
        }

        ov7251->link_freq_idx = i;

out_free_bus_cfg:
        v4l2_fwnode_endpoint_free(&bus_cfg);

        return ret;
}

static int ov7251_detect_chip(struct ov7251 *ov7251)
{
        u8 chip_id_high, chip_id_low, chip_rev;
        int ret;

        ret = ov7251_read_reg(ov7251, OV7251_CHIP_ID_HIGH, &chip_id_high);
        if (ret < 0 || chip_id_high != OV7251_CHIP_ID_HIGH_BYTE)
                return dev_err_probe(ov7251->dev, -ENODEV,
                                     "could not read ID high\n");

        ret = ov7251_read_reg(ov7251, OV7251_CHIP_ID_LOW, &chip_id_low);
        if (ret < 0 || chip_id_low != OV7251_CHIP_ID_LOW_BYTE)
                return dev_err_probe(ov7251->dev, -ENODEV,
                                     "could not read ID low\n");

        ret = ov7251_read_reg(ov7251, OV7251_SC_GP_IO_IN1, &chip_rev);
        if (ret < 0)
                return dev_err_probe(ov7251->dev, -ENODEV,
                                     "could not read revision\n");
        chip_rev >>= 4;

        dev_info(ov7251->dev,
                 "OV7251 revision %x (%s) detected at address 0x%02x\n",
                 chip_rev,
                 chip_rev == 0x4 ? "1A / 1B" :
                 chip_rev == 0x5 ? "1C / 1D" :
                 chip_rev == 0x6 ? "1E" :
                 chip_rev == 0x7 ? "1F" : "unknown",
                 ov7251->i2c_client->addr);

        return 0;
}

static int ov7251_init_ctrls(struct ov7251 *ov7251)
{
        int vblank_max, vblank_def;
        s64 pixel_rate;
        int hblank;

        v4l2_ctrl_handler_init(&ov7251->ctrls, 7);
        ov7251->ctrls.lock = &ov7251->lock;

        v4l2_ctrl_new_std(&ov7251->ctrls, &ov7251_ctrl_ops,
                          V4L2_CID_HFLIP, 0, 1, 1, 0);
        v4l2_ctrl_new_std(&ov7251->ctrls, &ov7251_ctrl_ops,
                          V4L2_CID_VFLIP, 0, 1, 1, 0);
        ov7251->exposure = v4l2_ctrl_new_std(&ov7251->ctrls, &ov7251_ctrl_ops,
                                             V4L2_CID_EXPOSURE, 1, 32, 1, 32);
        ov7251->gain = v4l2_ctrl_new_std(&ov7251->ctrls, &ov7251_ctrl_ops,
                                         V4L2_CID_GAIN, 16, 1023, 1, 16);
        v4l2_ctrl_new_std_menu_items(&ov7251->ctrls, &ov7251_ctrl_ops,
                                     V4L2_CID_TEST_PATTERN,
                                     ARRAY_SIZE(ov7251_test_pattern_menu) - 1,
                                     0, 0, ov7251_test_pattern_menu);

        pixel_rate = pixel_rates[ov7251->link_freq_idx];
        ov7251->pixel_clock = v4l2_ctrl_new_std(&ov7251->ctrls,
                                                &ov7251_ctrl_ops,
                                                V4L2_CID_PIXEL_RATE,
                                                pixel_rate, INT_MAX,
                                                pixel_rate, pixel_rate);
        ov7251->link_freq = v4l2_ctrl_new_int_menu(&ov7251->ctrls,
                                                   &ov7251_ctrl_ops,
                                                   V4L2_CID_LINK_FREQ,
                                                   ARRAY_SIZE(link_freq) - 1,
                                                   ov7251->link_freq_idx,
                                                   link_freq);
        if (ov7251->link_freq)
                ov7251->link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY;
        if (ov7251->pixel_clock)
                ov7251->pixel_clock->flags |= V4L2_CTRL_FLAG_READ_ONLY;

        hblank = OV7251_FIXED_PPL - ov7251->current_mode->width;
        ov7251->hblank = v4l2_ctrl_new_std(&ov7251->ctrls, &ov7251_ctrl_ops,
                                           V4L2_CID_HBLANK, hblank, hblank, 1,
                                           hblank);
        if (ov7251->hblank)
                ov7251->hblank->flags |= V4L2_CTRL_FLAG_READ_ONLY;

        vblank_max = OV7251_TIMING_MAX_VTS - ov7251->current_mode->height;
        vblank_def = ov7251->current_mode->vts - ov7251->current_mode->height;
        ov7251->vblank = v4l2_ctrl_new_std(&ov7251->ctrls, &ov7251_ctrl_ops,
                                           V4L2_CID_VBLANK,
                                           OV7251_TIMING_MIN_VTS, vblank_max, 1,
                                           vblank_def);

        ov7251->sd.ctrl_handler = &ov7251->ctrls;

        if (ov7251->ctrls.error) {
                v4l2_ctrl_handler_free(&ov7251->ctrls);
                return ov7251->ctrls.error;
        }

        return 0;
}

static int ov7251_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct ov7251 *ov7251;
        int ret;
        int i;

        ov7251 = devm_kzalloc(dev, sizeof(struct ov7251), GFP_KERNEL);
        if (!ov7251)
                return -ENOMEM;

        ov7251->i2c_client = client;
        ov7251->dev = dev;

        ret = ov7251_check_hwcfg(ov7251);
        if (ret)
                return ret;

        /* get system clock (xclk) */
        ov7251->xclk = devm_v4l2_sensor_clk_get(dev, NULL);
        if (IS_ERR(ov7251->xclk))
                return dev_err_probe(dev, PTR_ERR(ov7251->xclk),
                                     "could not get xclk");

        ov7251->xclk_freq = clk_get_rate(ov7251->xclk);

        for (i = 0; i < ARRAY_SIZE(supported_xclk_rates); i++)
                if (ov7251->xclk_freq == supported_xclk_rates[i])
                        break;

        if (i == ARRAY_SIZE(supported_xclk_rates))
                return dev_err_probe(dev, -EINVAL,
                                     "clock rate %u Hz is unsupported\n",
                                     ov7251->xclk_freq);

        ov7251->pll_cfgs = ov7251_pll_cfgs[i];

        ov7251->io_regulator = devm_regulator_get(dev, "vdddo");
        if (IS_ERR(ov7251->io_regulator)) {
                dev_err(dev, "cannot get io regulator\n");
                return PTR_ERR(ov7251->io_regulator);
        }

        ov7251->core_regulator = devm_regulator_get(dev, "vddd");
        if (IS_ERR(ov7251->core_regulator)) {
                dev_err(dev, "cannot get core regulator\n");
                return PTR_ERR(ov7251->core_regulator);
        }

        ov7251->analog_regulator = devm_regulator_get(dev, "vdda");
        if (IS_ERR(ov7251->analog_regulator)) {
                dev_err(dev, "cannot get analog regulator\n");
                return PTR_ERR(ov7251->analog_regulator);
        }

        ov7251->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
        if (IS_ERR(ov7251->enable_gpio)) {
                dev_err(dev, "cannot get enable gpio\n");
                return PTR_ERR(ov7251->enable_gpio);
        }

        mutex_init(&ov7251->lock);

        ov7251->current_mode = &ov7251_mode_info_data[0];
        ret = ov7251_init_ctrls(ov7251);
        if (ret) {
                dev_err_probe(dev, ret, "error during v4l2 ctrl init\n");
                goto destroy_mutex;
        }

        v4l2_i2c_subdev_init(&ov7251->sd, client, &ov7251_subdev_ops);
        ov7251->sd.internal_ops = &ov7251_internal_ops;
        ov7251->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
        ov7251->pad.flags = MEDIA_PAD_FL_SOURCE;
        ov7251->sd.dev = &client->dev;
        ov7251->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;

        ret = media_entity_pads_init(&ov7251->sd.entity, 1, &ov7251->pad);
        if (ret < 0) {
                dev_err(dev, "could not register media entity\n");
                goto free_ctrl;
        }

        ret = ov7251_set_power_on(ov7251->dev);
        if (ret)
                goto free_entity;

        ret = ov7251_detect_chip(ov7251);
        if (ret)
                goto power_down;

        pm_runtime_set_active(&client->dev);
        pm_runtime_get_noresume(&client->dev);
        pm_runtime_enable(&client->dev);

        ret = ov7251_read_reg(ov7251, OV7251_PRE_ISP_00,
                              &ov7251->pre_isp_00);
        if (ret < 0) {
                dev_err(dev, "could not read test pattern value\n");
                ret = -ENODEV;
                goto err_pm_runtime;
        }

        ret = ov7251_read_reg(ov7251, OV7251_TIMING_FORMAT1,
                              &ov7251->timing_format1);
        if (ret < 0) {
                dev_err(dev, "could not read vflip value\n");
                ret = -ENODEV;
                goto err_pm_runtime;
        }

        ret = ov7251_read_reg(ov7251, OV7251_TIMING_FORMAT2,
                              &ov7251->timing_format2);
        if (ret < 0) {
                dev_err(dev, "could not read hflip value\n");
                ret = -ENODEV;
                goto err_pm_runtime;
        }

        pm_runtime_set_autosuspend_delay(&client->dev, 1000);
        pm_runtime_use_autosuspend(&client->dev);
        pm_runtime_put_autosuspend(&client->dev);

        ret = v4l2_async_register_subdev(&ov7251->sd);
        if (ret < 0) {
                dev_err(dev, "could not register v4l2 device\n");
                goto free_entity;
        }

        ov7251_init_state(&ov7251->sd, NULL);

        return 0;

err_pm_runtime:
        pm_runtime_disable(ov7251->dev);
        pm_runtime_put_noidle(ov7251->dev);
power_down:
        ov7251_set_power_off(ov7251->dev);
free_entity:
        media_entity_cleanup(&ov7251->sd.entity);
free_ctrl:
        v4l2_ctrl_handler_free(&ov7251->ctrls);
destroy_mutex:
        mutex_destroy(&ov7251->lock);

        return ret;
}

static void ov7251_remove(struct i2c_client *client)
{
        struct v4l2_subdev *sd = i2c_get_clientdata(client);
        struct ov7251 *ov7251 = to_ov7251(sd);

        v4l2_async_unregister_subdev(&ov7251->sd);
        media_entity_cleanup(&ov7251->sd.entity);
        v4l2_ctrl_handler_free(&ov7251->ctrls);
        mutex_destroy(&ov7251->lock);

        pm_runtime_disable(ov7251->dev);
        if (!pm_runtime_status_suspended(ov7251->dev))
                ov7251_set_power_off(ov7251->dev);
        pm_runtime_set_suspended(ov7251->dev);
}

static const struct dev_pm_ops ov7251_pm_ops = {
        SET_RUNTIME_PM_OPS(ov7251_set_power_off, ov7251_set_power_on, NULL)
};

static const struct of_device_id ov7251_of_match[] = {
        { .compatible = "ovti,ov7251" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, ov7251_of_match);

static const struct acpi_device_id ov7251_acpi_match[] = {
        { "INT347E" },
        { }
};
MODULE_DEVICE_TABLE(acpi, ov7251_acpi_match);

static struct i2c_driver ov7251_i2c_driver = {
        .driver = {
                .of_match_table = ov7251_of_match,
                .acpi_match_table = ov7251_acpi_match,
                .name  = "ov7251",
                .pm = &ov7251_pm_ops,
        },
        .probe = ov7251_probe,
        .remove = ov7251_remove,
};

module_i2c_driver(ov7251_i2c_driver);

MODULE_DESCRIPTION("Omnivision OV7251 Camera Driver");
MODULE_AUTHOR("Todor Tomov <todor.tomov@linaro.org>");
MODULE_LICENSE("GPL v2");