// SPDX-License-Identifier: GPL-2.0-only
/*
 * Driver for AK8813 / AK8814 TV-ecoders from Asahi Kasei Microsystems Co., Ltd. (AKM)
 *
 * Copyright (C) 2010, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
 */

#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/videodev2.h>
#include <linux/module.h>

#include <media/i2c/ak881x.h>
#include <media/v4l2-common.h>
#include <media/v4l2-device.h>

#define AK881X_INTERFACE_MODE   0
#define AK881X_VIDEO_PROCESS1   1
#define AK881X_VIDEO_PROCESS2   2
#define AK881X_VIDEO_PROCESS3   3
#define AK881X_DAC_MODE         5
#define AK881X_STATUS           0x24
#define AK881X_DEVICE_ID        0x25
#define AK881X_DEVICE_REVISION  0x26

struct ak881x {
        struct v4l2_subdev subdev;
        struct ak881x_pdata *pdata;
        unsigned int lines;
        char revision;  /* DEVICE_REVISION content */
};

static int reg_read(struct i2c_client *client, const u8 reg)
{
        return i2c_smbus_read_byte_data(client, reg);
}

static int reg_write(struct i2c_client *client, const u8 reg,
                     const u8 data)
{
        return i2c_smbus_write_byte_data(client, reg, data);
}

static int reg_set(struct i2c_client *client, const u8 reg,
                   const u8 data, u8 mask)
{
        int ret = reg_read(client, reg);
        if (ret < 0)
                return ret;
        return reg_write(client, reg, (ret & ~mask) | (data & mask));
}

static struct ak881x *to_ak881x(const struct i2c_client *client)
{
        return container_of(i2c_get_clientdata(client), struct ak881x, subdev);
}

#ifdef CONFIG_VIDEO_ADV_DEBUG
static int ak881x_g_register(struct v4l2_subdev *sd,
                             struct v4l2_dbg_register *reg)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);

        if (reg->reg > 0x26)
                return -EINVAL;

        reg->size = 1;
        reg->val = reg_read(client, reg->reg);

        if (reg->val > 0xffff)
                return -EIO;

        return 0;
}

static int ak881x_s_register(struct v4l2_subdev *sd,
                             const struct v4l2_dbg_register *reg)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);

        if (reg->reg > 0x26)
                return -EINVAL;

        if (reg_write(client, reg->reg, reg->val) < 0)
                return -EIO;

        return 0;
}
#endif

static int ak881x_fill_fmt(struct v4l2_subdev *sd,
                struct v4l2_subdev_state *sd_state,
                struct v4l2_subdev_format *format)
{
        struct v4l2_mbus_framefmt *mf = &format->format;
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct ak881x *ak881x = to_ak881x(client);

        if (format->pad)
                return -EINVAL;

        v4l_bound_align_image(&mf->width, 0, 720, 2,
                              &mf->height, 0, ak881x->lines, 1, 0);
        mf->field       = V4L2_FIELD_INTERLACED;
        mf->code        = MEDIA_BUS_FMT_YUYV8_2X8;
        mf->colorspace  = V4L2_COLORSPACE_SMPTE170M;

        return 0;
}

static int ak881x_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)
                return -EINVAL;

        code->code = MEDIA_BUS_FMT_YUYV8_2X8;
        return 0;
}

static int ak881x_get_selection(struct v4l2_subdev *sd,
                                struct v4l2_subdev_state *sd_state,
                                struct v4l2_subdev_selection *sel)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct ak881x *ak881x = to_ak881x(client);

        if (sel->which != V4L2_SUBDEV_FORMAT_ACTIVE)
                return -EINVAL;

        switch (sel->target) {
        case V4L2_SEL_TGT_CROP_BOUNDS:
                sel->r.left = 0;
                sel->r.top = 0;
                sel->r.width = 720;
                sel->r.height = ak881x->lines;
                return 0;
        default:
                return -EINVAL;
        }
}

static int ak881x_s_std_output(struct v4l2_subdev *sd, v4l2_std_id std)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct ak881x *ak881x = to_ak881x(client);
        u8 vp1;

        if (std == V4L2_STD_NTSC_443) {
                vp1 = 3;
                ak881x->lines = 480;
        } else if (std == V4L2_STD_PAL_M) {
                vp1 = 5;
                ak881x->lines = 480;
        } else if (std == V4L2_STD_PAL_60) {
                vp1 = 7;
                ak881x->lines = 480;
        } else if (std & V4L2_STD_NTSC) {
                vp1 = 0;
                ak881x->lines = 480;
        } else if (std & V4L2_STD_PAL) {
                vp1 = 0xf;
                ak881x->lines = 576;
        } else {
                /* No SECAM or PAL_N/Nc supported */
                return -EINVAL;
        }

        reg_set(client, AK881X_VIDEO_PROCESS1, vp1, 0xf);

        return 0;
}

static int ak881x_s_stream(struct v4l2_subdev *sd, int enable)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        struct ak881x *ak881x = to_ak881x(client);

        if (enable) {
                u8 dac;
                /* For colour-bar testing set bit 6 of AK881X_VIDEO_PROCESS1 */
                /* Default: composite output */
                if (ak881x->pdata->flags & AK881X_COMPONENT)
                        dac = 3;
                else
                        dac = 4;
                /* Turn on the DAC(s) */
                reg_write(client, AK881X_DAC_MODE, dac);
                dev_dbg(&client->dev, "chip status 0x%x\n",
                        reg_read(client, AK881X_STATUS));
        } else {
                /* ...and clear bit 6 of AK881X_VIDEO_PROCESS1 here */
                reg_write(client, AK881X_DAC_MODE, 0);
                dev_dbg(&client->dev, "chip status 0x%x\n",
                        reg_read(client, AK881X_STATUS));
        }

        return 0;
}

static const struct v4l2_subdev_core_ops ak881x_subdev_core_ops = {
#ifdef CONFIG_VIDEO_ADV_DEBUG
        .g_register     = ak881x_g_register,
        .s_register     = ak881x_s_register,
#endif
};

static const struct v4l2_subdev_video_ops ak881x_subdev_video_ops = {
        .s_std_output   = ak881x_s_std_output,
        .s_stream       = ak881x_s_stream,
};

static const struct v4l2_subdev_pad_ops ak881x_subdev_pad_ops = {
        .enum_mbus_code = ak881x_enum_mbus_code,
        .get_selection  = ak881x_get_selection,
        .set_fmt        = ak881x_fill_fmt,
        .get_fmt        = ak881x_fill_fmt,
};

static const struct v4l2_subdev_ops ak881x_subdev_ops = {
        .core   = &ak881x_subdev_core_ops,
        .video  = &ak881x_subdev_video_ops,
        .pad    = &ak881x_subdev_pad_ops,
};

static int ak881x_probe(struct i2c_client *client)
{
        struct i2c_adapter *adapter = client->adapter;
        struct ak881x *ak881x;
        u8 ifmode, data;

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
                dev_warn(&adapter->dev,
                         "I2C-Adapter doesn't support I2C_FUNC_SMBUS_WORD\n");
                return -EIO;
        }

        ak881x = devm_kzalloc(&client->dev, sizeof(*ak881x), GFP_KERNEL);
        if (!ak881x)
                return -ENOMEM;

        v4l2_i2c_subdev_init(&ak881x->subdev, client, &ak881x_subdev_ops);

        data = reg_read(client, AK881X_DEVICE_ID);

        switch (data) {
        case 0x13:
        case 0x14:
                break;
        default:
                dev_err(&client->dev,
                        "No ak881x chip detected, register read %x\n", data);
                return -ENODEV;
        }

        ak881x->revision = reg_read(client, AK881X_DEVICE_REVISION);
        ak881x->pdata = client->dev.platform_data;

        if (ak881x->pdata) {
                if (ak881x->pdata->flags & AK881X_FIELD)
                        ifmode = 4;
                else
                        ifmode = 0;

                switch (ak881x->pdata->flags & AK881X_IF_MODE_MASK) {
                case AK881X_IF_MODE_BT656:
                        ifmode |= 1;
                        break;
                case AK881X_IF_MODE_MASTER:
                        ifmode |= 2;
                        break;
                case AK881X_IF_MODE_SLAVE:
                default:
                        break;
                }

                dev_dbg(&client->dev, "IF mode %x\n", ifmode);

                /*
                 * "Line Blanking No." seems to be the same as the number of
                 * "black" lines on, e.g., SuperH VOU, whose default value of 20
                 * "incidentally" matches ak881x' default
                 */
                reg_write(client, AK881X_INTERFACE_MODE, ifmode | (20 << 3));
        }

        /* Hardware default: NTSC-M */
        ak881x->lines = 480;

        dev_info(&client->dev, "Detected an ak881x chip ID %x, revision %x\n",
                 data, ak881x->revision);

        return 0;
}

static void ak881x_remove(struct i2c_client *client)
{
        struct ak881x *ak881x = to_ak881x(client);

        v4l2_device_unregister_subdev(&ak881x->subdev);
}

static const struct i2c_device_id ak881x_id[] = {
        { .name = "ak8813" },
        { .name = "ak8814" },
        { }
};
MODULE_DEVICE_TABLE(i2c, ak881x_id);

static struct i2c_driver ak881x_i2c_driver = {
        .driver = {
                .name = "ak881x",
        },
        .probe          = ak881x_probe,
        .remove         = ak881x_remove,
        .id_table       = ak881x_id,
};

module_i2c_driver(ak881x_i2c_driver);

MODULE_DESCRIPTION("TV-output driver for ak8813/ak8814");
MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");
MODULE_LICENSE("GPL v2");