// SPDX-License-Identifier: GPL-2.0
//
// mt9v011 -Micron 1/4-Inch VGA Digital Image Sensor
//
// Copyright (c) 2009 Mauro Carvalho Chehab <mchehab@kernel.org>

#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/videodev2.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <asm/div64.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ctrls.h>
#include <media/i2c/mt9v011.h>

MODULE_DESCRIPTION("Micron mt9v011 sensor driver");
MODULE_AUTHOR("Mauro Carvalho Chehab");
MODULE_LICENSE("GPL v2");

static int debug;
module_param(debug, int, 0);
MODULE_PARM_DESC(debug, "Debug level (0-2)");

#define R00_MT9V011_CHIP_VERSION        0x00
#define R01_MT9V011_ROWSTART            0x01
#define R02_MT9V011_COLSTART            0x02
#define R03_MT9V011_HEIGHT              0x03
#define R04_MT9V011_WIDTH               0x04
#define R05_MT9V011_HBLANK              0x05
#define R06_MT9V011_VBLANK              0x06
#define R07_MT9V011_OUT_CTRL            0x07
#define R09_MT9V011_SHUTTER_WIDTH       0x09
#define R0A_MT9V011_CLK_SPEED           0x0a
#define R0B_MT9V011_RESTART             0x0b
#define R0C_MT9V011_SHUTTER_DELAY       0x0c
#define R0D_MT9V011_RESET               0x0d
#define R1E_MT9V011_DIGITAL_ZOOM        0x1e
#define R20_MT9V011_READ_MODE           0x20
#define R2B_MT9V011_GREEN_1_GAIN        0x2b
#define R2C_MT9V011_BLUE_GAIN           0x2c
#define R2D_MT9V011_RED_GAIN            0x2d
#define R2E_MT9V011_GREEN_2_GAIN        0x2e
#define R35_MT9V011_GLOBAL_GAIN         0x35
#define RF1_MT9V011_CHIP_ENABLE         0xf1

#define MT9V011_VERSION                 0x8232
#define MT9V011_REV_B_VERSION           0x8243

struct mt9v011 {
        struct v4l2_subdev sd;
        struct media_pad pad;
        struct v4l2_ctrl_handler ctrls;
        unsigned width, height;
        unsigned xtal;
        unsigned hflip:1;
        unsigned vflip:1;

        u16 global_gain, exposure;
        s16 red_bal, blue_bal;
};

static inline struct mt9v011 *to_mt9v011(struct v4l2_subdev *sd)
{
        return container_of(sd, struct mt9v011, sd);
}

static int mt9v011_read(struct v4l2_subdev *sd, unsigned char addr)
{
        struct i2c_client *c = v4l2_get_subdevdata(sd);
        __be16 buffer;
        int rc, val;

        rc = i2c_master_send(c, &addr, 1);
        if (rc != 1)
                v4l2_dbg(0, debug, sd,
                         "i2c i/o error: rc == %d (should be 1)\n", rc);

        msleep(10);

        rc = i2c_master_recv(c, (char *)&buffer, 2);
        if (rc != 2)
                v4l2_dbg(0, debug, sd,
                         "i2c i/o error: rc == %d (should be 2)\n", rc);

        val = be16_to_cpu(buffer);

        v4l2_dbg(2, debug, sd, "mt9v011: read 0x%02x = 0x%04x\n", addr, val);

        return val;
}

static void mt9v011_write(struct v4l2_subdev *sd, unsigned char addr,
                                 u16 value)
{
        struct i2c_client *c = v4l2_get_subdevdata(sd);
        unsigned char buffer[3];
        int rc;

        buffer[0] = addr;
        buffer[1] = value >> 8;
        buffer[2] = value & 0xff;

        v4l2_dbg(2, debug, sd,
                 "mt9v011: writing 0x%02x 0x%04x\n", buffer[0], value);
        rc = i2c_master_send(c, buffer, 3);
        if (rc != 3)
                v4l2_dbg(0, debug, sd,
                         "i2c i/o error: rc == %d (should be 3)\n", rc);
}


struct i2c_reg_value {
        unsigned char reg;
        u16           value;
};

/*
 * Values used at the original driver
 * Some values are marked as Reserved at the datasheet
 */
static const struct i2c_reg_value mt9v011_init_default[] = {
                { R0D_MT9V011_RESET, 0x0001 },
                { R0D_MT9V011_RESET, 0x0000 },

                { R0C_MT9V011_SHUTTER_DELAY, 0x0000 },
                { R09_MT9V011_SHUTTER_WIDTH, 0x1fc },

                { R0A_MT9V011_CLK_SPEED, 0x0000 },
                { R1E_MT9V011_DIGITAL_ZOOM,  0x0000 },

                { R07_MT9V011_OUT_CTRL, 0x0002 },       /* chip enable */
};


static u16 calc_mt9v011_gain(s16 lineargain)
{

        u16 digitalgain = 0;
        u16 analogmult = 0;
        u16 analoginit = 0;

        if (lineargain < 0)
                lineargain = 0;

        /* recommended minimum */
        lineargain += 0x0020;

        if (lineargain > 2047)
                lineargain = 2047;

        if (lineargain > 1023) {
                digitalgain = 3;
                analogmult = 3;
                analoginit = lineargain / 16;
        } else if (lineargain > 511) {
                digitalgain = 1;
                analogmult = 3;
                analoginit = lineargain / 8;
        } else if (lineargain > 255) {
                analogmult = 3;
                analoginit = lineargain / 4;
        } else if (lineargain > 127) {
                analogmult = 1;
                analoginit = lineargain / 2;
        } else
                analoginit = lineargain;

        return analoginit + (analogmult << 7) + (digitalgain << 9);

}

static void set_balance(struct v4l2_subdev *sd)
{
        struct mt9v011 *core = to_mt9v011(sd);
        u16 green_gain, blue_gain, red_gain;
        u16 exposure;
        s16 bal;

        exposure = core->exposure;

        green_gain = calc_mt9v011_gain(core->global_gain);

        bal = core->global_gain;
        bal += (core->blue_bal * core->global_gain / (1 << 7));
        blue_gain = calc_mt9v011_gain(bal);

        bal = core->global_gain;
        bal += (core->red_bal * core->global_gain / (1 << 7));
        red_gain = calc_mt9v011_gain(bal);

        mt9v011_write(sd, R2B_MT9V011_GREEN_1_GAIN, green_gain);
        mt9v011_write(sd, R2E_MT9V011_GREEN_2_GAIN, green_gain);
        mt9v011_write(sd, R2C_MT9V011_BLUE_GAIN, blue_gain);
        mt9v011_write(sd, R2D_MT9V011_RED_GAIN, red_gain);
        mt9v011_write(sd, R09_MT9V011_SHUTTER_WIDTH, exposure);
}

static void calc_fps(struct v4l2_subdev *sd, u32 *numerator, u32 *denominator)
{
        struct mt9v011 *core = to_mt9v011(sd);
        unsigned height, width, hblank, vblank, speed;
        unsigned row_time, t_time;
        u64 frames_per_ms;
        unsigned tmp;

        height = mt9v011_read(sd, R03_MT9V011_HEIGHT);
        width = mt9v011_read(sd, R04_MT9V011_WIDTH);
        hblank = mt9v011_read(sd, R05_MT9V011_HBLANK);
        vblank = mt9v011_read(sd, R06_MT9V011_VBLANK);
        speed = mt9v011_read(sd, R0A_MT9V011_CLK_SPEED);

        row_time = (width + 113 + hblank) * (speed + 2);
        t_time = row_time * (height + vblank + 1);

        frames_per_ms = core->xtal * 1000l;
        do_div(frames_per_ms, t_time);
        tmp = frames_per_ms;

        v4l2_dbg(1, debug, sd, "Programmed to %u.%03u fps (%d pixel clcks)\n",
                tmp / 1000, tmp % 1000, t_time);

        if (numerator && denominator) {
                *numerator = 1000;
                *denominator = (u32)frames_per_ms;
        }
}

static u16 calc_speed(struct v4l2_subdev *sd, u32 numerator, u32 denominator)
{
        struct mt9v011 *core = to_mt9v011(sd);
        unsigned height, width, hblank, vblank;
        unsigned row_time, line_time;
        u64 t_time, speed;

        /* Avoid bogus calculus */
        if (!numerator || !denominator)
                return 0;

        height = mt9v011_read(sd, R03_MT9V011_HEIGHT);
        width = mt9v011_read(sd, R04_MT9V011_WIDTH);
        hblank = mt9v011_read(sd, R05_MT9V011_HBLANK);
        vblank = mt9v011_read(sd, R06_MT9V011_VBLANK);

        row_time = width + 113 + hblank;
        line_time = height + vblank + 1;

        t_time = core->xtal * ((u64)numerator);
        /* round to the closest value */
        t_time += denominator / 2;
        do_div(t_time, denominator);

        speed = t_time;
        do_div(speed, row_time * line_time);

        /* Avoid having a negative value for speed */
        if (speed < 2)
                speed = 0;
        else
                speed -= 2;

        /* Avoid speed overflow */
        if (speed > 15)
                return 15;

        return (u16)speed;
}

static void set_res(struct v4l2_subdev *sd)
{
        struct mt9v011 *core = to_mt9v011(sd);
        unsigned vstart, hstart;

        /*
         * The mt9v011 doesn't have scaling. So, in order to select the desired
         * resolution, we're cropping at the middle of the sensor.
         * hblank and vblank should be adjusted, in order to warrant that
         * we'll preserve the line timings for 30 fps, no matter what resolution
         * is selected.
         * NOTE: datasheet says that width (and height) should be filled with
         * width-1. However, this doesn't work, since one pixel per line will
         * be missing.
         */

        hstart = 20 + (640 - core->width) / 2;
        mt9v011_write(sd, R02_MT9V011_COLSTART, hstart);
        mt9v011_write(sd, R04_MT9V011_WIDTH, core->width);
        mt9v011_write(sd, R05_MT9V011_HBLANK, 771 - core->width);

        vstart = 8 + (480 - core->height) / 2;
        mt9v011_write(sd, R01_MT9V011_ROWSTART, vstart);
        mt9v011_write(sd, R03_MT9V011_HEIGHT, core->height);
        mt9v011_write(sd, R06_MT9V011_VBLANK, 508 - core->height);

        calc_fps(sd, NULL, NULL);
};

static void set_read_mode(struct v4l2_subdev *sd)
{
        struct mt9v011 *core = to_mt9v011(sd);
        unsigned mode = 0x1000;

        if (core->hflip)
                mode |= 0x4000;

        if (core->vflip)
                mode |= 0x8000;

        mt9v011_write(sd, R20_MT9V011_READ_MODE, mode);
}

static int mt9v011_reset(struct v4l2_subdev *sd, u32 val)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(mt9v011_init_default); i++)
                mt9v011_write(sd, mt9v011_init_default[i].reg,
                               mt9v011_init_default[i].value);

        set_balance(sd);
        set_res(sd);
        set_read_mode(sd);

        return 0;
}

static int mt9v011_enum_mbus_code(struct v4l2_subdev *sd,
                struct v4l2_subdev_state *sd_state,
                struct v4l2_subdev_mbus_code_enum *code)
{
        if (code->pad || code->index > 0)
                return -EINVAL;

        code->code = MEDIA_BUS_FMT_SGRBG8_1X8;
        return 0;
}

static int mt9v011_set_fmt(struct v4l2_subdev *sd,
                struct v4l2_subdev_state *sd_state,
                struct v4l2_subdev_format *format)
{
        struct v4l2_mbus_framefmt *fmt = &format->format;
        struct mt9v011 *core = to_mt9v011(sd);

        if (format->pad || fmt->code != MEDIA_BUS_FMT_SGRBG8_1X8)
                return -EINVAL;

        v4l_bound_align_image(&fmt->width, 48, 639, 1,
                              &fmt->height, 32, 480, 1, 0);
        fmt->field = V4L2_FIELD_NONE;
        fmt->colorspace = V4L2_COLORSPACE_SRGB;

        if (format->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
                core->width = fmt->width;
                core->height = fmt->height;

                set_res(sd);
        } else {
                *v4l2_subdev_state_get_format(sd_state, 0) = *fmt;
        }

        return 0;
}

static int mt9v011_get_frame_interval(struct v4l2_subdev *sd,
                                      struct v4l2_subdev_state *sd_state,
                                      struct v4l2_subdev_frame_interval *ival)
{
        /*
         * FIXME: Implement support for V4L2_SUBDEV_FORMAT_TRY, using the V4L2
         * subdev active state API.
         */
        if (ival->which != V4L2_SUBDEV_FORMAT_ACTIVE)
                return -EINVAL;

        calc_fps(sd,
                 &ival->interval.numerator,
                 &ival->interval.denominator);

        return 0;
}

static int mt9v011_set_frame_interval(struct v4l2_subdev *sd,
                                      struct v4l2_subdev_state *sd_state,
                                      struct v4l2_subdev_frame_interval *ival)
{
        struct v4l2_fract *tpf = &ival->interval;
        u16 speed;

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

        speed = calc_speed(sd, tpf->numerator, tpf->denominator);

        mt9v011_write(sd, R0A_MT9V011_CLK_SPEED, speed);
        v4l2_dbg(1, debug, sd, "Setting speed to %d\n", speed);

        /* Recalculate and update fps info */
        calc_fps(sd, &tpf->numerator, &tpf->denominator);

        return 0;
}

#ifdef CONFIG_VIDEO_ADV_DEBUG
static int mt9v011_g_register(struct v4l2_subdev *sd,
                              struct v4l2_dbg_register *reg)
{
        reg->val = mt9v011_read(sd, reg->reg & 0xff);
        reg->size = 2;

        return 0;
}

static int mt9v011_s_register(struct v4l2_subdev *sd,
                              const struct v4l2_dbg_register *reg)
{
        mt9v011_write(sd, reg->reg & 0xff, reg->val & 0xffff);

        return 0;
}
#endif

static int mt9v011_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct mt9v011 *core =
                container_of(ctrl->handler, struct mt9v011, ctrls);
        struct v4l2_subdev *sd = &core->sd;

        switch (ctrl->id) {
        case V4L2_CID_GAIN:
                core->global_gain = ctrl->val;
                break;
        case V4L2_CID_EXPOSURE:
                core->exposure = ctrl->val;
                break;
        case V4L2_CID_RED_BALANCE:
                core->red_bal = ctrl->val;
                break;
        case V4L2_CID_BLUE_BALANCE:
                core->blue_bal = ctrl->val;
                break;
        case V4L2_CID_HFLIP:
                core->hflip = ctrl->val;
                set_read_mode(sd);
                return 0;
        case V4L2_CID_VFLIP:
                core->vflip = ctrl->val;
                set_read_mode(sd);
                return 0;
        default:
                return -EINVAL;
        }

        set_balance(sd);
        return 0;
}

static const struct v4l2_ctrl_ops mt9v011_ctrl_ops = {
        .s_ctrl = mt9v011_s_ctrl,
};

static const struct v4l2_subdev_core_ops mt9v011_core_ops = {
        .reset = mt9v011_reset,
#ifdef CONFIG_VIDEO_ADV_DEBUG
        .g_register = mt9v011_g_register,
        .s_register = mt9v011_s_register,
#endif
};

static const struct v4l2_subdev_pad_ops mt9v011_pad_ops = {
        .enum_mbus_code = mt9v011_enum_mbus_code,
        .set_fmt = mt9v011_set_fmt,
        .get_frame_interval = mt9v011_get_frame_interval,
        .set_frame_interval = mt9v011_set_frame_interval,
};

static const struct v4l2_subdev_ops mt9v011_ops = {
        .core  = &mt9v011_core_ops,
        .pad   = &mt9v011_pad_ops,
};


/****************************************************************************
                        I2C Client & Driver
 ****************************************************************************/

static int mt9v011_probe(struct i2c_client *c)
{
        u16 version;
        struct mt9v011 *core;
        struct v4l2_subdev *sd;
        int ret;

        /* Check if the adapter supports the needed features */
        if (!i2c_check_functionality(c->adapter,
             I2C_FUNC_SMBUS_READ_BYTE | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
                return -EIO;

        core = devm_kzalloc(&c->dev, sizeof(struct mt9v011), GFP_KERNEL);
        if (!core)
                return -ENOMEM;

        sd = &core->sd;
        v4l2_i2c_subdev_init(sd, c, &mt9v011_ops);

        core->pad.flags = MEDIA_PAD_FL_SOURCE;
        sd->entity.function = MEDIA_ENT_F_CAM_SENSOR;

        ret = media_entity_pads_init(&sd->entity, 1, &core->pad);
        if (ret < 0)
                return ret;

        /* Check if the sensor is really a MT9V011 */
        version = mt9v011_read(sd, R00_MT9V011_CHIP_VERSION);
        if ((version != MT9V011_VERSION) &&
            (version != MT9V011_REV_B_VERSION)) {
                v4l2_info(sd, "*** unknown micron chip detected (0x%04x).\n",
                          version);
                return -EINVAL;
        }

        v4l2_ctrl_handler_init(&core->ctrls, 5);
        v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
                          V4L2_CID_GAIN, 0, (1 << 12) - 1 - 0x20, 1, 0x20);
        v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
                          V4L2_CID_EXPOSURE, 0, 2047, 1, 0x01fc);
        v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
                          V4L2_CID_RED_BALANCE, -(1 << 9), (1 << 9) - 1, 1, 0);
        v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
                          V4L2_CID_BLUE_BALANCE, -(1 << 9), (1 << 9) - 1, 1, 0);
        v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
                          V4L2_CID_HFLIP, 0, 1, 1, 0);
        v4l2_ctrl_new_std(&core->ctrls, &mt9v011_ctrl_ops,
                          V4L2_CID_VFLIP, 0, 1, 1, 0);

        if (core->ctrls.error) {
                int ret = core->ctrls.error;

                v4l2_err(sd, "control initialization error %d\n", ret);
                v4l2_ctrl_handler_free(&core->ctrls);
                return ret;
        }
        core->sd.ctrl_handler = &core->ctrls;

        core->global_gain = 0x0024;
        core->exposure = 0x01fc;
        core->width  = 640;
        core->height = 480;
        core->xtal = 27000000;  /* Hz */

        if (c->dev.platform_data) {
                struct mt9v011_platform_data *pdata = c->dev.platform_data;

                core->xtal = pdata->xtal;
                v4l2_dbg(1, debug, sd, "xtal set to %d.%03d MHz\n",
                        core->xtal / 1000000, (core->xtal / 1000) % 1000);
        }

        v4l_info(c, "chip found @ 0x%02x (%s - chip version 0x%04x)\n",
                 c->addr << 1, c->adapter->name, version);

        return 0;
}

static void mt9v011_remove(struct i2c_client *c)
{
        struct v4l2_subdev *sd = i2c_get_clientdata(c);
        struct mt9v011 *core = to_mt9v011(sd);

        v4l2_dbg(1, debug, sd,
                "mt9v011.c: removing mt9v011 adapter on address 0x%x\n",
                c->addr << 1);

        v4l2_device_unregister_subdev(sd);
        v4l2_ctrl_handler_free(&core->ctrls);
}

/* ----------------------------------------------------------------------- */

static const struct i2c_device_id mt9v011_id[] = {
        { "mt9v011" },
        { }
};
MODULE_DEVICE_TABLE(i2c, mt9v011_id);

static struct i2c_driver mt9v011_driver = {
        .driver = {
                .name   = "mt9v011",
        },
        .probe          = mt9v011_probe,
        .remove         = mt9v011_remove,
        .id_table       = mt9v011_id,
};

module_i2c_driver(mt9v011_driver);