/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Sony IMX377 12‑Mp MIPI CSI‑2 image sensor driver
 *
 * Copyright (c) 2025
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/regulator/consumer.h>
#include <linux/of_graph.h>
#include <linux/videodev2.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
#include <media/v4l2-fwnode.h>
#include <media/v4l2-subdev.h>

#define IMX377_REG_STANDBY   0x3000 /* bit0 */
#define IMX377_REG_MODE_SEL  0x0100 /* standby/streaming */ /* not listed but standard */
#define IMX377_REG_GAIN      0x3009 /* + 8:2 */
#define IMX377_REG_EXPOSURE  0x300B /* +C */
#define IMX377_REG_VMAX      0x30F7 /* +F8 +F9[3:0] */
#define IMX377_REG_HMAX      0x30F5 /* +F6 */
/* ...additional key registers here... */

struct imx377_mode {
        u32 width;
        u32 height;
        u32 code;          /* MEDIA_BUS_FMT */
        u32 hts;           /* line length in pixels */
        u32 vts;           /* frame length in lines */
        u64 link_freq;     /* Hz */
};

static const struct imx377_mode mode_12mp_raw12 = {
        .width      = 4056,
        .height     = 3040,
        .code       = MEDIA_BUS_FMT_SRGGB12_1X12,
        .hts        = 0x0172, /* 0x30F5 default */
        .vts        = 0x0CB2, /* 0x30F7 default */
        .link_freq  = 576000000ULL,
};

struct imx377 {
        struct v4l2_subdev     sd;
        struct media_pad       pad;
        struct v4l2_ctrl_handler ctrls;
        struct mutex           lock; /* serialize controls */

        struct clk             *xclk;
        struct regulator       *avdd; /* 2.8V */
        struct regulator       *dvdd; /* 1.1V */
        struct regulator       *dovdd;/* 1.8V */
        struct gpio_desc       *reset_gpio;
        struct gpio_desc       *pwdn_gpio;

        const struct imx377_mode *cur_mode;
        bool                   streaming;
};

static inline int imx377_write_reg(struct i2c_client *client, u16 reg, u8 val)
{
        u8 buf[3] = {reg >> 8, reg & 0xff, val};
        int ret = i2c_master_send(client, buf, 3);
        return (ret == 3) ? 0 : (ret < 0 ? ret : -EIO);
}

static int imx377_set_streaming(struct imx377 *priv, bool on)
{
        struct i2c_client *client = v4l2_get_subdevdata(&priv->sd);
        int ret;

        if (on) {
                /* power up */
                regulator_bulk_enable(3, (struct regulator_bulk_data[]){
                        {"dvdd", priv->dvdd}, {"avdd", priv->avdd}, {"dovdd", priv->dovdd}
                });
                clk_prepare_enable(priv->xclk);
                gpiod_set_value_cansleep(priv->reset_gpio, 1);
                gpiod_set_value_cansleep(priv->pwdn_gpio, 0);
                usleep_range(5000, 6000);
                /* TODO: write mode registers */
                ret = imx377_write_reg(client, IMX377_REG_MODE_SEL, 0x01);
                if (ret)
                        return ret;
                priv->streaming = true;
        } else {
                ret = imx377_write_reg(client, IMX377_REG_MODE_SEL, 0x00);
                priv->streaming = false;
                clk_disable_unprepare(priv->xclk);
                gpiod_set_value_cansleep(priv->pwdn_gpio, 1);
                gpiod_set_value_cansleep(priv->reset_gpio, 0);
                regulator_bulk_disable(3, (struct regulator_bulk_data[]){
                        {"dvdd", priv->dvdd}, {"avdd", priv->avdd}, {"dovdd", priv->dovdd}
                });
        }
        return 0;
}

static int imx377_s_stream(struct v4l2_subdev *sd, int enable)
{
        struct imx377 *priv = container_of(sd, struct imx377, sd);
        int ret;

        mutex_lock(&priv->lock);
        ret = imx377_set_streaming(priv, enable);
        mutex_unlock(&priv->lock);
        return ret;
}

/* --- control ops, pad ops, probe(), remove() omitted for brevity --- */

static const struct i2c_device_id imx377_id[] = {
        {"imx377", 0},
        {}
};
MODULE_DEVICE_TABLE(i2c, imx377_id);

static const struct of_device_id imx377_of[] = {
        { .compatible = "sony,imx377" },
        {}
};
MODULE_DEVICE_TABLE(of, imx377_of);

static struct i2c_driver imx377_i2c_driver = {
        .driver = {
                .name  = "imx377",
                .of_match_table = imx377_of,
        },
        .probe  = imx377_probe,
        .remove = imx377_remove,
        .id_table = imx377_id,
};
module_i2c_driver(imx377_i2c_driver);

MODULE_DESCRIPTION("Sony IMX377 CMOS Image Sensor driver");
MODULE_LICENSE("GPL v2");