root/drivers/media/i2c/st-mipid02.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Driver for ST MIPID02 CSI-2 to PARALLEL bridge
 *
 * Copyright (C) STMicroelectronics SA 2019
 * Authors: Mickael Guene <mickael.guene@st.com>
 *          for STMicroelectronics.
 *
 *
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/of_graph.h>
#include <linux/regulator/consumer.h>
#include <media/mipi-csi2.h>
#include <media/v4l2-async.h>
#include <media/v4l2-cci.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
#include <media/v4l2-fwnode.h>
#include <media/v4l2-subdev.h>

#define MIPID02_CLK_LANE_WR_REG1        CCI_REG8(0x01)
#define MIPID02_CLK_LANE_REG1           CCI_REG8(0x02)
#define MIPID02_CLK_LANE_REG3           CCI_REG8(0x04)
#define MIPID02_DATA_LANE0_REG1         CCI_REG8(0x05)
#define MIPID02_DATA_LANE0_REG2         CCI_REG8(0x06)
#define MIPID02_DATA_LANE1_REG1         CCI_REG8(0x09)
#define MIPID02_DATA_LANE1_REG2         CCI_REG8(0x0a)
#define MIPID02_MODE_REG1               CCI_REG8(0x14)
#define MIPID02_MODE_REG2               CCI_REG8(0x15)
#define MIPID02_DATA_ID_RREG            CCI_REG8(0x17)
#define MIPID02_DATA_SELECTION_CTRL     CCI_REG8(0x19)
#define MIPID02_PIX_WIDTH_CTRL          CCI_REG8(0x1e)
#define MIPID02_PIX_WIDTH_CTRL_EMB      CCI_REG8(0x1f)

/* Bits definition for MIPID02_CLK_LANE_REG1 */
#define CLK_ENABLE                                      BIT(0)
/* Bits definition for MIPID02_CLK_LANE_REG3 */
#define CLK_MIPI_CSI                                    BIT(1)
/* Bits definition for MIPID02_DATA_LANE0_REG1 */
#define DATA_ENABLE                                     BIT(0)
/* Bits definition for MIPID02_DATA_LANEx_REG2 */
#define DATA_MIPI_CSI                                   BIT(0)
/* Bits definition for MIPID02_MODE_REG1 */
#define MODE_DATA_SWAP                                  BIT(2)
#define MODE_NO_BYPASS                                  BIT(6)
/* Bits definition for MIPID02_MODE_REG2 */
#define MODE_HSYNC_ACTIVE_HIGH                          BIT(1)
#define MODE_VSYNC_ACTIVE_HIGH                          BIT(2)
#define MODE_PCLK_SAMPLE_RISING                         BIT(3)
/* Bits definition for MIPID02_DATA_SELECTION_CTRL */
#define SELECTION_MANUAL_DATA                           BIT(2)
#define SELECTION_MANUAL_WIDTH                          BIT(3)

static const u32 mipid02_supported_fmt_codes[] = {
        MEDIA_BUS_FMT_SBGGR8_1X8, MEDIA_BUS_FMT_SGBRG8_1X8,
        MEDIA_BUS_FMT_SGRBG8_1X8, MEDIA_BUS_FMT_SRGGB8_1X8,
        MEDIA_BUS_FMT_SBGGR10_1X10, MEDIA_BUS_FMT_SGBRG10_1X10,
        MEDIA_BUS_FMT_SGRBG10_1X10, MEDIA_BUS_FMT_SRGGB10_1X10,
        MEDIA_BUS_FMT_SBGGR12_1X12, MEDIA_BUS_FMT_SGBRG12_1X12,
        MEDIA_BUS_FMT_SGRBG12_1X12, MEDIA_BUS_FMT_SRGGB12_1X12,
        MEDIA_BUS_FMT_YUYV8_1X16, MEDIA_BUS_FMT_YVYU8_1X16,
        MEDIA_BUS_FMT_UYVY8_1X16, MEDIA_BUS_FMT_VYUY8_1X16,
        MEDIA_BUS_FMT_RGB565_1X16, MEDIA_BUS_FMT_BGR888_1X24,
        MEDIA_BUS_FMT_Y8_1X8, MEDIA_BUS_FMT_JPEG_1X8
};

/* regulator supplies */
static const char * const mipid02_supply_name[] = {
        "VDDE", /* 1.8V digital I/O supply */
        "VDDIN", /* 1V8 voltage regulator supply */
};

#define MIPID02_NUM_SUPPLIES            ARRAY_SIZE(mipid02_supply_name)

#define MIPID02_SINK_0                  0
#define MIPID02_SINK_1                  1
#define MIPID02_SOURCE                  2
#define MIPID02_PAD_NB                  3

struct mipid02_dev {
        struct i2c_client *i2c_client;
        struct regulator_bulk_data supplies[MIPID02_NUM_SUPPLIES];
        struct v4l2_subdev sd;
        struct regmap *regmap;
        struct media_pad pad[MIPID02_PAD_NB];
        struct clk *xclk;
        struct gpio_desc *reset_gpio;
        /* endpoints info */
        struct v4l2_fwnode_endpoint rx;
        struct v4l2_fwnode_endpoint tx;
        /* remote source */
        struct v4l2_async_notifier notifier;
        struct v4l2_subdev *s_subdev;
        u16 s_subdev_pad_id;
        /* registers */
        struct {
                u8 clk_lane_reg1;
                u8 data_lane0_reg1;
                u8 data_lane1_reg1;
                u8 mode_reg1;
                u8 mode_reg2;
                u8 data_selection_ctrl;
                u8 data_id_rreg;
                u8 pix_width_ctrl;
                u8 pix_width_ctrl_emb;
        } r;
};

static int bpp_from_code(__u32 code)
{
        switch (code) {
        case MEDIA_BUS_FMT_SBGGR8_1X8:
        case MEDIA_BUS_FMT_SGBRG8_1X8:
        case MEDIA_BUS_FMT_SGRBG8_1X8:
        case MEDIA_BUS_FMT_SRGGB8_1X8:
        case MEDIA_BUS_FMT_Y8_1X8:
                return 8;
        case MEDIA_BUS_FMT_SBGGR10_1X10:
        case MEDIA_BUS_FMT_SGBRG10_1X10:
        case MEDIA_BUS_FMT_SGRBG10_1X10:
        case MEDIA_BUS_FMT_SRGGB10_1X10:
                return 10;
        case MEDIA_BUS_FMT_SBGGR12_1X12:
        case MEDIA_BUS_FMT_SGBRG12_1X12:
        case MEDIA_BUS_FMT_SGRBG12_1X12:
        case MEDIA_BUS_FMT_SRGGB12_1X12:
                return 12;
        case MEDIA_BUS_FMT_YUYV8_1X16:
        case MEDIA_BUS_FMT_YVYU8_1X16:
        case MEDIA_BUS_FMT_UYVY8_1X16:
        case MEDIA_BUS_FMT_VYUY8_1X16:
        case MEDIA_BUS_FMT_RGB565_1X16:
                return 16;
        case MEDIA_BUS_FMT_BGR888_1X24:
                return 24;
        default:
                return 0;
        }
}

static u8 data_type_from_code(__u32 code)
{
        switch (code) {
        case MEDIA_BUS_FMT_SBGGR8_1X8:
        case MEDIA_BUS_FMT_SGBRG8_1X8:
        case MEDIA_BUS_FMT_SGRBG8_1X8:
        case MEDIA_BUS_FMT_SRGGB8_1X8:
        case MEDIA_BUS_FMT_Y8_1X8:
                return MIPI_CSI2_DT_RAW8;
        case MEDIA_BUS_FMT_SBGGR10_1X10:
        case MEDIA_BUS_FMT_SGBRG10_1X10:
        case MEDIA_BUS_FMT_SGRBG10_1X10:
        case MEDIA_BUS_FMT_SRGGB10_1X10:
                return MIPI_CSI2_DT_RAW10;
        case MEDIA_BUS_FMT_SBGGR12_1X12:
        case MEDIA_BUS_FMT_SGBRG12_1X12:
        case MEDIA_BUS_FMT_SGRBG12_1X12:
        case MEDIA_BUS_FMT_SRGGB12_1X12:
                return MIPI_CSI2_DT_RAW12;
        case MEDIA_BUS_FMT_YUYV8_1X16:
        case MEDIA_BUS_FMT_YVYU8_1X16:
        case MEDIA_BUS_FMT_UYVY8_1X16:
        case MEDIA_BUS_FMT_VYUY8_1X16:
                return MIPI_CSI2_DT_YUV422_8B;
        case MEDIA_BUS_FMT_BGR888_1X24:
                return MIPI_CSI2_DT_RGB888;
        case MEDIA_BUS_FMT_RGB565_1X16:
                return MIPI_CSI2_DT_RGB565;
        default:
                return 0;
        }
}

static __u32 get_fmt_code(__u32 code)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(mipid02_supported_fmt_codes); i++) {
                if (code == mipid02_supported_fmt_codes[i])
                        return code;
        }

        return mipid02_supported_fmt_codes[0];
}

static __u32 serial_to_parallel_code(__u32 serial)
{
        if (serial == MEDIA_BUS_FMT_RGB565_1X16)
                return MEDIA_BUS_FMT_RGB565_2X8_LE;
        if (serial == MEDIA_BUS_FMT_YUYV8_1X16)
                return MEDIA_BUS_FMT_YUYV8_2X8;
        if (serial == MEDIA_BUS_FMT_YVYU8_1X16)
                return MEDIA_BUS_FMT_YVYU8_2X8;
        if (serial == MEDIA_BUS_FMT_UYVY8_1X16)
                return MEDIA_BUS_FMT_UYVY8_2X8;
        if (serial == MEDIA_BUS_FMT_VYUY8_1X16)
                return MEDIA_BUS_FMT_VYUY8_2X8;
        if (serial == MEDIA_BUS_FMT_BGR888_1X24)
                return MEDIA_BUS_FMT_BGR888_3X8;

        return serial;
}

static inline struct mipid02_dev *to_mipid02_dev(struct v4l2_subdev *sd)
{
        return container_of(sd, struct mipid02_dev, sd);
}

static int mipid02_get_regulators(struct mipid02_dev *bridge)
{
        unsigned int i;

        for (i = 0; i < MIPID02_NUM_SUPPLIES; i++)
                bridge->supplies[i].supply = mipid02_supply_name[i];

        return devm_regulator_bulk_get(&bridge->i2c_client->dev,
                                       MIPID02_NUM_SUPPLIES,
                                       bridge->supplies);
}

static void mipid02_apply_reset(struct mipid02_dev *bridge)
{
        gpiod_set_value_cansleep(bridge->reset_gpio, 0);
        usleep_range(5000, 10000);
        gpiod_set_value_cansleep(bridge->reset_gpio, 1);
        usleep_range(5000, 10000);
        gpiod_set_value_cansleep(bridge->reset_gpio, 0);
        usleep_range(5000, 10000);
}

static int mipid02_set_power_on(struct device *dev)
{
        struct v4l2_subdev *sd = dev_get_drvdata(dev);
        struct mipid02_dev *bridge = to_mipid02_dev(sd);
        struct i2c_client *client = bridge->i2c_client;
        int ret;

        ret = clk_prepare_enable(bridge->xclk);
        if (ret) {
                dev_err(&client->dev, "%s: failed to enable clock\n", __func__);
                return ret;
        }

        ret = regulator_bulk_enable(MIPID02_NUM_SUPPLIES,
                                    bridge->supplies);
        if (ret) {
                dev_err(&client->dev, "%s: failed to enable regulators\n",
                            __func__);
                goto xclk_off;
        }

        if (bridge->reset_gpio) {
                dev_dbg(&client->dev, "apply reset");
                mipid02_apply_reset(bridge);
        } else {
                dev_dbg(&client->dev, "don't apply reset");
                usleep_range(5000, 10000);
        }

        return 0;

xclk_off:
        clk_disable_unprepare(bridge->xclk);
        return ret;
}

static int mipid02_set_power_off(struct device *dev)
{
        struct v4l2_subdev *sd = dev_get_drvdata(dev);
        struct mipid02_dev *bridge = to_mipid02_dev(sd);

        regulator_bulk_disable(MIPID02_NUM_SUPPLIES, bridge->supplies);
        clk_disable_unprepare(bridge->xclk);

        return 0;
}

static int mipid02_detect(struct mipid02_dev *bridge)
{
        u64 reg;

        /*
         * There is no version registers. Just try to read register
         * MIPID02_CLK_LANE_WR_REG1.
         */
        return cci_read(bridge->regmap, MIPID02_CLK_LANE_WR_REG1, &reg, NULL);
}

/*
 * We need to know link frequency to setup clk_lane_reg1 timings. Link frequency
 * will be retrieve from connected device via v4l2_get_link_freq, bit per pixel
 * and number of lanes.
 */
static int mipid02_configure_from_rx_speed(struct mipid02_dev *bridge,
                                           struct v4l2_mbus_framefmt *fmt)
{
        struct media_pad *remote =
                &bridge->s_subdev->entity.pads[bridge->s_subdev_pad_id];
        struct i2c_client *client = bridge->i2c_client;
        struct v4l2_fwnode_endpoint *ep = &bridge->rx;
        u32 bpp = bpp_from_code(fmt->code);
        /*
         * clk_lane_reg1 requires 4 times the unit interval time, and bitrate
         * is twice the link frequency, hence ui_4 = 1000000000 * 4 / 2
         */
        u64 ui_4 = 2000000000;
        s64 link_freq;

        link_freq = v4l2_get_link_freq(remote, bpp,
                                       2 * ep->bus.mipi_csi2.num_data_lanes);
        if (link_freq < 0) {
                dev_err(&client->dev, "Failed to get link frequency");
                return -EINVAL;
        }

        dev_dbg(&client->dev, "detect link_freq = %lld Hz", link_freq);
        ui_4 = div64_u64(ui_4, link_freq);
        bridge->r.clk_lane_reg1 |= ui_4 << 2;

        return 0;
}

static int mipid02_configure_clk_lane(struct mipid02_dev *bridge)
{
        struct i2c_client *client = bridge->i2c_client;
        struct v4l2_fwnode_endpoint *ep = &bridge->rx;
        bool *polarities = ep->bus.mipi_csi2.lane_polarities;

        /* midid02 doesn't support clock lane remapping */
        if (ep->bus.mipi_csi2.clock_lane != 0) {
                dev_err(&client->dev, "clk lane must be map to lane 0\n");
                return -EINVAL;
        }
        bridge->r.clk_lane_reg1 |= (polarities[0] << 1) | CLK_ENABLE;

        return 0;
}

static int mipid02_configure_data0_lane(struct mipid02_dev *bridge, int nb,
                                        bool are_lanes_swap, bool *polarities)
{
        bool are_pin_swap = are_lanes_swap ? polarities[2] : polarities[1];

        if (nb == 1 && are_lanes_swap)
                return 0;

        /*
         * data lane 0 as pin swap polarity reversed compared to clock and
         * data lane 1
         */
        if (!are_pin_swap)
                bridge->r.data_lane0_reg1 = 1 << 1;
        bridge->r.data_lane0_reg1 |= DATA_ENABLE;

        return 0;
}

static int mipid02_configure_data1_lane(struct mipid02_dev *bridge, int nb,
                                        bool are_lanes_swap, bool *polarities)
{
        bool are_pin_swap = are_lanes_swap ? polarities[1] : polarities[2];

        if (nb == 1 && !are_lanes_swap)
                return 0;

        if (are_pin_swap)
                bridge->r.data_lane1_reg1 = 1 << 1;
        bridge->r.data_lane1_reg1 |= DATA_ENABLE;

        return 0;
}

static int mipid02_configure_from_rx(struct mipid02_dev *bridge,
                                     struct v4l2_mbus_framefmt *fmt)
{
        struct v4l2_fwnode_endpoint *ep = &bridge->rx;
        bool are_lanes_swap = ep->bus.mipi_csi2.data_lanes[0] == 2;
        bool *polarities = ep->bus.mipi_csi2.lane_polarities;
        int nb = ep->bus.mipi_csi2.num_data_lanes;
        int ret;

        ret = mipid02_configure_clk_lane(bridge);
        if (ret)
                return ret;

        ret = mipid02_configure_data0_lane(bridge, nb, are_lanes_swap,
                                           polarities);
        if (ret)
                return ret;

        ret = mipid02_configure_data1_lane(bridge, nb, are_lanes_swap,
                                           polarities);
        if (ret)
                return ret;

        bridge->r.mode_reg1 |= are_lanes_swap ? MODE_DATA_SWAP : 0;
        bridge->r.mode_reg1 |= (nb - 1) << 1;

        return mipid02_configure_from_rx_speed(bridge, fmt);
}

static int mipid02_configure_from_tx(struct mipid02_dev *bridge)
{
        struct v4l2_fwnode_endpoint *ep = &bridge->tx;

        bridge->r.data_selection_ctrl = SELECTION_MANUAL_WIDTH;
        bridge->r.pix_width_ctrl = ep->bus.parallel.bus_width;
        bridge->r.pix_width_ctrl_emb = ep->bus.parallel.bus_width;
        if (ep->bus.parallel.flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH)
                bridge->r.mode_reg2 |= MODE_HSYNC_ACTIVE_HIGH;
        if (ep->bus.parallel.flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH)
                bridge->r.mode_reg2 |= MODE_VSYNC_ACTIVE_HIGH;
        if (ep->bus.parallel.flags & V4L2_MBUS_PCLK_SAMPLE_RISING)
                bridge->r.mode_reg2 |= MODE_PCLK_SAMPLE_RISING;

        return 0;
}

static int mipid02_configure_from_code(struct mipid02_dev *bridge,
                                       struct v4l2_mbus_framefmt *fmt)
{
        u8 data_type;

        bridge->r.data_id_rreg = 0;

        if (fmt->code != MEDIA_BUS_FMT_JPEG_1X8) {
                bridge->r.data_selection_ctrl |= SELECTION_MANUAL_DATA;

                data_type = data_type_from_code(fmt->code);
                if (!data_type)
                        return -EINVAL;
                bridge->r.data_id_rreg = data_type;
        }

        return 0;
}

static int mipid02_disable_streams(struct v4l2_subdev *sd,
                                   struct v4l2_subdev_state *state, u32 pad,
                                   u64 streams_mask)
{
        struct mipid02_dev *bridge = to_mipid02_dev(sd);
        struct i2c_client *client = bridge->i2c_client;
        int ret = -EINVAL;

        if (!bridge->s_subdev)
                goto error;

        ret = v4l2_subdev_disable_streams(bridge->s_subdev,
                                          bridge->s_subdev_pad_id, BIT(0));
        if (ret)
                goto error;

        /* Disable all lanes */
        cci_write(bridge->regmap, MIPID02_CLK_LANE_REG1, 0, &ret);
        cci_write(bridge->regmap, MIPID02_DATA_LANE0_REG1, 0, &ret);
        cci_write(bridge->regmap, MIPID02_DATA_LANE1_REG1, 0, &ret);
        if (ret)
                goto error;

        pm_runtime_put_autosuspend(&client->dev);

error:
        if (ret)
                dev_err(&client->dev, "failed to stream off %d", ret);

        return ret;
}

static int mipid02_enable_streams(struct v4l2_subdev *sd,
                                  struct v4l2_subdev_state *state, u32 pad,
                                  u64 streams_mask)
{
        struct mipid02_dev *bridge = to_mipid02_dev(sd);
        struct i2c_client *client = bridge->i2c_client;
        struct v4l2_mbus_framefmt *fmt;
        int ret = -EINVAL;

        if (!bridge->s_subdev)
                return ret;

        memset(&bridge->r, 0, sizeof(bridge->r));

        fmt = v4l2_subdev_state_get_format(state, MIPID02_SINK_0);

        /* build registers content */
        ret = mipid02_configure_from_rx(bridge, fmt);
        if (ret)
                return ret;
        ret = mipid02_configure_from_tx(bridge);
        if (ret)
                return ret;
        ret = mipid02_configure_from_code(bridge, fmt);
        if (ret)
                return ret;

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

        /* write mipi registers */
        cci_write(bridge->regmap, MIPID02_CLK_LANE_REG1,
                  bridge->r.clk_lane_reg1, &ret);
        cci_write(bridge->regmap, MIPID02_CLK_LANE_REG3, CLK_MIPI_CSI, &ret);
        cci_write(bridge->regmap, MIPID02_DATA_LANE0_REG1,
                  bridge->r.data_lane0_reg1, &ret);
        cci_write(bridge->regmap, MIPID02_DATA_LANE0_REG2, DATA_MIPI_CSI, &ret);
        cci_write(bridge->regmap, MIPID02_DATA_LANE1_REG1,
                  bridge->r.data_lane1_reg1, &ret);
        cci_write(bridge->regmap, MIPID02_DATA_LANE1_REG2, DATA_MIPI_CSI, &ret);
        cci_write(bridge->regmap, MIPID02_MODE_REG1,
                  MODE_NO_BYPASS | bridge->r.mode_reg1, &ret);
        cci_write(bridge->regmap, MIPID02_MODE_REG2, bridge->r.mode_reg2, &ret);
        cci_write(bridge->regmap, MIPID02_DATA_ID_RREG, bridge->r.data_id_rreg,
                  &ret);
        cci_write(bridge->regmap, MIPID02_DATA_SELECTION_CTRL,
                  bridge->r.data_selection_ctrl, &ret);
        cci_write(bridge->regmap, MIPID02_PIX_WIDTH_CTRL,
                  bridge->r.pix_width_ctrl, &ret);
        cci_write(bridge->regmap, MIPID02_PIX_WIDTH_CTRL_EMB,
                  bridge->r.pix_width_ctrl_emb, &ret);
        if (ret)
                goto error;

        ret = v4l2_subdev_enable_streams(bridge->s_subdev,
                                         bridge->s_subdev_pad_id, BIT(0));
        if (ret)
                goto error;

        return 0;

error:
        cci_write(bridge->regmap, MIPID02_CLK_LANE_REG1, 0, &ret);
        cci_write(bridge->regmap, MIPID02_DATA_LANE0_REG1, 0, &ret);
        cci_write(bridge->regmap, MIPID02_DATA_LANE1_REG1, 0, &ret);

        pm_runtime_put_autosuspend(&client->dev);
        return ret;
}

static const struct v4l2_mbus_framefmt default_fmt = {
        .code = MEDIA_BUS_FMT_SBGGR8_1X8,
        .field = V4L2_FIELD_NONE,
        .colorspace = V4L2_COLORSPACE_SRGB,
        .ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT,
        .quantization = V4L2_QUANTIZATION_FULL_RANGE,
        .xfer_func = V4L2_XFER_FUNC_DEFAULT,
        .width = 640,
        .height = 480,
};

static int mipid02_init_state(struct v4l2_subdev *sd,
                              struct v4l2_subdev_state *state)
{
        *v4l2_subdev_state_get_format(state, MIPID02_SINK_0) = default_fmt;
        /* MIPID02_SINK_1 isn't supported yet */
        *v4l2_subdev_state_get_format(state, MIPID02_SOURCE) = default_fmt;

        return 0;
}

static int mipid02_enum_mbus_code(struct v4l2_subdev *sd,
                                 struct v4l2_subdev_state *sd_state,
                                 struct v4l2_subdev_mbus_code_enum *code)
{
        struct v4l2_mbus_framefmt *sink_fmt;
        int ret = 0;

        switch (code->pad) {
        case MIPID02_SINK_0:
                if (code->index >= ARRAY_SIZE(mipid02_supported_fmt_codes))
                        ret = -EINVAL;
                else
                        code->code = mipid02_supported_fmt_codes[code->index];
                break;
        case MIPID02_SOURCE:
                if (code->index == 0) {
                        sink_fmt = v4l2_subdev_state_get_format(sd_state,
                                                                MIPID02_SINK_0);
                        code->code = serial_to_parallel_code(sink_fmt->code);
                } else {
                        ret = -EINVAL;
                }
                break;
        default:
                ret = -EINVAL;
        }

        return ret;
}

static int mipid02_set_fmt(struct v4l2_subdev *sd,
                           struct v4l2_subdev_state *sd_state,
                           struct v4l2_subdev_format *fmt)
{
        struct mipid02_dev *bridge = to_mipid02_dev(sd);
        struct i2c_client *client = bridge->i2c_client;
        struct v4l2_mbus_framefmt *pad_fmt;

        dev_dbg(&client->dev, "%s for %d", __func__, fmt->pad);

        /* second CSI-2 pad not yet supported */
        if (fmt->pad == MIPID02_SINK_1)
                return -EINVAL;

        pad_fmt = v4l2_subdev_state_get_format(sd_state, fmt->pad);
        fmt->format.code = get_fmt_code(fmt->format.code);

        /* code may need to be converted */
        if (fmt->pad == MIPID02_SOURCE)
                fmt->format.code = serial_to_parallel_code(fmt->format.code);

        *pad_fmt = fmt->format;

        /* Propagate the format to the source pad in case of sink pad update */
        if (fmt->pad == MIPID02_SINK_0) {
                pad_fmt = v4l2_subdev_state_get_format(sd_state,
                                                       MIPID02_SOURCE);
                *pad_fmt = fmt->format;
                pad_fmt->code = serial_to_parallel_code(fmt->format.code);
        }

        return 0;
}

static const struct v4l2_subdev_video_ops mipid02_video_ops = {
        .s_stream = v4l2_subdev_s_stream_helper,
};

static const struct v4l2_subdev_pad_ops mipid02_pad_ops = {
        .enum_mbus_code = mipid02_enum_mbus_code,
        .get_fmt = v4l2_subdev_get_fmt,
        .set_fmt = mipid02_set_fmt,
        .enable_streams = mipid02_enable_streams,
        .disable_streams = mipid02_disable_streams,
};

static const struct v4l2_subdev_ops mipid02_subdev_ops = {
        .video = &mipid02_video_ops,
        .pad = &mipid02_pad_ops,
};

static const struct v4l2_subdev_internal_ops mipid02_subdev_internal_ops = {
        .init_state = mipid02_init_state,
};

static const struct media_entity_operations mipid02_subdev_entity_ops = {
        .link_validate = v4l2_subdev_link_validate,
};

static int mipid02_async_bound(struct v4l2_async_notifier *notifier,
                               struct v4l2_subdev *s_subdev,
                               struct v4l2_async_connection *asd)
{
        struct mipid02_dev *bridge = to_mipid02_dev(notifier->sd);
        struct i2c_client *client = bridge->i2c_client;
        int source_pad;
        int ret;

        dev_dbg(&client->dev, "sensor_async_bound call %p", s_subdev);

        source_pad = media_entity_get_fwnode_pad(&s_subdev->entity,
                                                 s_subdev->fwnode,
                                                 MEDIA_PAD_FL_SOURCE);
        if (source_pad < 0) {
                dev_err(&client->dev, "Couldn't find output pad for subdev %s\n",
                        s_subdev->name);
                return source_pad;
        }

        ret = media_create_pad_link(&s_subdev->entity, source_pad,
                                    &bridge->sd.entity, 0,
                                    MEDIA_LNK_FL_ENABLED |
                                    MEDIA_LNK_FL_IMMUTABLE);
        if (ret) {
                dev_err(&client->dev, "Couldn't create media link %d", ret);
                return ret;
        }

        bridge->s_subdev = s_subdev;
        bridge->s_subdev_pad_id = source_pad;

        return 0;
}

static void mipid02_async_unbind(struct v4l2_async_notifier *notifier,
                                 struct v4l2_subdev *s_subdev,
                                 struct v4l2_async_connection *asd)
{
        struct mipid02_dev *bridge = to_mipid02_dev(notifier->sd);

        bridge->s_subdev = NULL;
}

static const struct v4l2_async_notifier_operations mipid02_notifier_ops = {
        .bound          = mipid02_async_bound,
        .unbind         = mipid02_async_unbind,
};

static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
{
        struct v4l2_fwnode_endpoint ep = { .bus_type = V4L2_MBUS_CSI2_DPHY };
        struct i2c_client *client = bridge->i2c_client;
        struct v4l2_async_connection *asd;
        struct device_node *ep_node;
        int ret;

        /* parse rx (endpoint 0) */
        ep_node = of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node,
                                                0, 0);
        if (!ep_node) {
                dev_err(&client->dev, "unable to find port0 ep");
                ret = -EINVAL;
                goto error;
        }

        ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep_node), &ep);
        if (ret) {
                dev_err(&client->dev, "Could not parse v4l2 endpoint %d\n",
                        ret);
                goto error_of_node_put;
        }

        /* do some sanity checks */
        if (ep.bus.mipi_csi2.num_data_lanes > 2) {
                dev_err(&client->dev, "max supported data lanes is 2 / got %d",
                        ep.bus.mipi_csi2.num_data_lanes);
                ret = -EINVAL;
                goto error_of_node_put;
        }

        /* register it for later use */
        bridge->rx = ep;

        /* register async notifier so we get noticed when sensor is connected */
        v4l2_async_subdev_nf_init(&bridge->notifier, &bridge->sd);
        asd = v4l2_async_nf_add_fwnode_remote(&bridge->notifier,
                                              of_fwnode_handle(ep_node),
                                              struct v4l2_async_connection);
        of_node_put(ep_node);

        if (IS_ERR(asd)) {
                dev_err(&client->dev, "fail to register asd to notifier %pe",
                        asd);
                return PTR_ERR(asd);
        }
        bridge->notifier.ops = &mipid02_notifier_ops;

        ret = v4l2_async_nf_register(&bridge->notifier);
        if (ret)
                v4l2_async_nf_cleanup(&bridge->notifier);

        return ret;

error_of_node_put:
        of_node_put(ep_node);
error:

        return ret;
}

static int mipid02_parse_tx_ep(struct mipid02_dev *bridge)
{
        struct v4l2_fwnode_endpoint ep = { .bus_type = V4L2_MBUS_PARALLEL };
        struct i2c_client *client = bridge->i2c_client;
        struct device_node *ep_node;
        int ret;

        /* parse tx (endpoint 2) */
        ep_node = of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node,
                                                2, 0);
        if (!ep_node) {
                dev_err(&client->dev, "unable to find port1 ep");
                ret = -EINVAL;
                goto error;
        }

        ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep_node), &ep);
        if (ret) {
                dev_err(&client->dev, "Could not parse v4l2 endpoint\n");
                goto error_of_node_put;
        }

        of_node_put(ep_node);
        bridge->tx = ep;

        return 0;

error_of_node_put:
        of_node_put(ep_node);
error:

        return -EINVAL;
}

static int mipid02_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct mipid02_dev *bridge;
        u32 clk_freq;
        int ret;

        bridge = devm_kzalloc(dev, sizeof(*bridge), GFP_KERNEL);
        if (!bridge)
                return -ENOMEM;

        bridge->i2c_client = client;
        v4l2_i2c_subdev_init(&bridge->sd, client, &mipid02_subdev_ops);

        /* got and check clock */
        bridge->xclk = devm_clk_get(dev, "xclk");
        if (IS_ERR(bridge->xclk)) {
                dev_err(dev, "failed to get xclk\n");
                return PTR_ERR(bridge->xclk);
        }

        clk_freq = clk_get_rate(bridge->xclk);
        if (clk_freq < 6000000 || clk_freq > 27000000) {
                dev_err(dev, "xclk freq must be in 6-27 Mhz range. got %d Hz\n",
                        clk_freq);
                return -EINVAL;
        }

        bridge->reset_gpio = devm_gpiod_get_optional(dev, "reset",
                                                     GPIOD_OUT_HIGH);

        if (IS_ERR(bridge->reset_gpio)) {
                dev_err(dev, "failed to get reset GPIO\n");
                return PTR_ERR(bridge->reset_gpio);
        }

        ret = mipid02_get_regulators(bridge);
        if (ret) {
                dev_err(dev, "failed to get regulators %d", ret);
                return ret;
        }

        /* Initialise the regmap for further cci access */
        bridge->regmap = devm_cci_regmap_init_i2c(client, 16);
        if (IS_ERR(bridge->regmap))
                return dev_err_probe(dev, PTR_ERR(bridge->regmap),
                                     "failed to get cci regmap\n");

        bridge->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
        bridge->sd.entity.function = MEDIA_ENT_F_VID_IF_BRIDGE;
        bridge->sd.internal_ops = &mipid02_subdev_internal_ops;
        bridge->sd.entity.ops = &mipid02_subdev_entity_ops;
        bridge->pad[0].flags = MEDIA_PAD_FL_SINK;
        bridge->pad[1].flags = MEDIA_PAD_FL_SINK;
        bridge->pad[2].flags = MEDIA_PAD_FL_SOURCE;
        ret = media_entity_pads_init(&bridge->sd.entity, MIPID02_PAD_NB,
                                     bridge->pad);
        if (ret) {
                dev_err(&client->dev, "pads init failed %d", ret);
                return ret;
        }

        ret = v4l2_subdev_init_finalize(&bridge->sd);
        if (ret < 0) {
                dev_err(dev, "subdev init error: %d\n", ret);
                goto entity_cleanup;
        }

        /* enable clock, power and reset device if available */
        ret = mipid02_set_power_on(&client->dev);
        if (ret)
                goto entity_cleanup;

        ret = mipid02_detect(bridge);
        if (ret) {
                dev_err(&client->dev, "failed to detect mipid02 %d", ret);
                goto power_off;
        }

        ret = mipid02_parse_tx_ep(bridge);
        if (ret) {
                dev_err(&client->dev, "failed to parse tx %d", ret);
                goto power_off;
        }

        ret = mipid02_parse_rx_ep(bridge);
        if (ret) {
                dev_err(&client->dev, "failed to parse rx %d", ret);
                goto power_off;
        }

        /* Enable runtime PM and turn off the device */
        pm_runtime_set_active(dev);
        pm_runtime_get_noresume(&client->dev);
        pm_runtime_enable(dev);

        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(&bridge->sd);
        if (ret < 0) {
                dev_err(&client->dev, "v4l2_async_register_subdev failed %d",
                            ret);
                goto unregister_notifier;
        }

        dev_info(&client->dev, "mipid02 device probe successfully");

        return 0;

unregister_notifier:
        v4l2_async_nf_unregister(&bridge->notifier);
        v4l2_async_nf_cleanup(&bridge->notifier);
        pm_runtime_disable(&client->dev);
        pm_runtime_set_suspended(&client->dev);
power_off:
        mipid02_set_power_off(&client->dev);
entity_cleanup:
        media_entity_cleanup(&bridge->sd.entity);

        return ret;
}

static void mipid02_remove(struct i2c_client *client)
{
        struct v4l2_subdev *sd = i2c_get_clientdata(client);
        struct mipid02_dev *bridge = to_mipid02_dev(sd);

        v4l2_async_nf_unregister(&bridge->notifier);
        v4l2_async_nf_cleanup(&bridge->notifier);
        v4l2_async_unregister_subdev(&bridge->sd);

        pm_runtime_disable(&client->dev);
        if (!pm_runtime_status_suspended(&client->dev))
                mipid02_set_power_off(&client->dev);
        pm_runtime_set_suspended(&client->dev);
        media_entity_cleanup(&bridge->sd.entity);
}

static const struct of_device_id mipid02_dt_ids[] = {
        { .compatible = "st,st-mipid02" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mipid02_dt_ids);

static const struct dev_pm_ops mipid02_pm_ops = {
        RUNTIME_PM_OPS(mipid02_set_power_off, mipid02_set_power_on, NULL)
};

static struct i2c_driver mipid02_i2c_driver = {
        .driver = {
                .name  = "st-mipid02",
                .of_match_table = mipid02_dt_ids,
                .pm = pm_ptr(&mipid02_pm_ops),
        },
        .probe = mipid02_probe,
        .remove = mipid02_remove,
};

module_i2c_driver(mipid02_i2c_driver);

MODULE_AUTHOR("Mickael Guene <mickael.guene@st.com>");
MODULE_DESCRIPTION("STMicroelectronics MIPID02 CSI-2 bridge driver");
MODULE_LICENSE("GPL v2");