// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2005-2006 Micronas USA Inc.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/videodev2.h>
#include <linux/ioctl.h>
#include <linux/slab.h>
#include <media/v4l2-subdev.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ctrls.h>

#define TW2804_REG_AUTOGAIN             0x02
#define TW2804_REG_HUE                  0x0f
#define TW2804_REG_SATURATION           0x10
#define TW2804_REG_CONTRAST             0x11
#define TW2804_REG_BRIGHTNESS           0x12
#define TW2804_REG_COLOR_KILLER         0x14
#define TW2804_REG_GAIN                 0x3c
#define TW2804_REG_CHROMA_GAIN          0x3d
#define TW2804_REG_BLUE_BALANCE         0x3e
#define TW2804_REG_RED_BALANCE          0x3f

struct tw2804 {
        struct v4l2_subdev sd;
        struct v4l2_ctrl_handler hdl;
        u8 channel:2;
        u8 input:1;
        int norm;
};

static const u8 global_registers[] = {
        0x39, 0x00,
        0x3a, 0xff,
        0x3b, 0x84,
        0x3c, 0x80,
        0x3d, 0x80,
        0x3e, 0x82,
        0x3f, 0x82,
        0x78, 0x00,
        0xff, 0xff, /* Terminator (reg 0xff does not exist) */
};

static const u8 channel_registers[] = {
        0x01, 0xc4,
        0x02, 0xa5,
        0x03, 0x20,
        0x04, 0xd0,
        0x05, 0x20,
        0x06, 0xd0,
        0x07, 0x88,
        0x08, 0x20,
        0x09, 0x07,
        0x0a, 0xf0,
        0x0b, 0x07,
        0x0c, 0xf0,
        0x0d, 0x40,
        0x0e, 0xd2,
        0x0f, 0x80,
        0x10, 0x80,
        0x11, 0x80,
        0x12, 0x80,
        0x13, 0x1f,
        0x14, 0x00,
        0x15, 0x00,
        0x16, 0x00,
        0x17, 0x00,
        0x18, 0xff,
        0x19, 0xff,
        0x1a, 0xff,
        0x1b, 0xff,
        0x1c, 0xff,
        0x1d, 0xff,
        0x1e, 0xff,
        0x1f, 0xff,
        0x20, 0x07,
        0x21, 0x07,
        0x22, 0x00,
        0x23, 0x91,
        0x24, 0x51,
        0x25, 0x03,
        0x26, 0x00,
        0x27, 0x00,
        0x28, 0x00,
        0x29, 0x00,
        0x2a, 0x00,
        0x2b, 0x00,
        0x2c, 0x00,
        0x2d, 0x00,
        0x2e, 0x00,
        0x2f, 0x00,
        0x30, 0x00,
        0x31, 0x00,
        0x32, 0x00,
        0x33, 0x00,
        0x34, 0x00,
        0x35, 0x00,
        0x36, 0x00,
        0x37, 0x00,
        0xff, 0xff, /* Terminator (reg 0xff does not exist) */
};

static int write_reg(struct i2c_client *client, u8 reg, u8 value, u8 channel)
{
        return i2c_smbus_write_byte_data(client, reg | (channel << 6), value);
}

static int write_regs(struct i2c_client *client, const u8 *regs, u8 channel)
{
        int ret;
        int i;

        for (i = 0; regs[i] != 0xff; i += 2) {
                ret = i2c_smbus_write_byte_data(client,
                                regs[i] | (channel << 6), regs[i + 1]);
                if (ret < 0)
                        return ret;
        }
        return 0;
}

static int read_reg(struct i2c_client *client, u8 reg, u8 channel)
{
        return i2c_smbus_read_byte_data(client, (reg) | (channel << 6));
}

static inline struct tw2804 *to_state(struct v4l2_subdev *sd)
{
        return container_of(sd, struct tw2804, sd);
}

static inline struct tw2804 *to_state_from_ctrl(struct v4l2_ctrl *ctrl)
{
        return container_of(ctrl->handler, struct tw2804, hdl);
}

static int tw2804_log_status(struct v4l2_subdev *sd)
{
        struct tw2804 *state = to_state(sd);

        v4l2_info(sd, "Standard: %s\n",
                        state->norm & V4L2_STD_525_60 ? "60 Hz" : "50 Hz");
        v4l2_info(sd, "Channel: %d\n", state->channel);
        v4l2_info(sd, "Input: %d\n", state->input);
        return v4l2_ctrl_subdev_log_status(sd);
}

/*
 * These volatile controls are needed because all four channels share
 * these controls. So a change made to them through one channel would
 * require another channel to be updated.
 *
 * Normally this would have been done in a different way, but since the one
 * board that uses this driver sees this single chip as if it was on four
 * different i2c adapters (each adapter belonging to a separate instance of
 * the same USB driver) there is no reliable method that I have found to let
 * the instances know about each other.
 *
 * So implementing these global registers as volatile is the best we can do.
 */
static int tw2804_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
{
        struct tw2804 *state = to_state_from_ctrl(ctrl);
        struct i2c_client *client = v4l2_get_subdevdata(&state->sd);

        switch (ctrl->id) {
        case V4L2_CID_GAIN:
                ctrl->val = read_reg(client, TW2804_REG_GAIN, 0);
                return 0;

        case V4L2_CID_CHROMA_GAIN:
                ctrl->val = read_reg(client, TW2804_REG_CHROMA_GAIN, 0);
                return 0;

        case V4L2_CID_BLUE_BALANCE:
                ctrl->val = read_reg(client, TW2804_REG_BLUE_BALANCE, 0);
                return 0;

        case V4L2_CID_RED_BALANCE:
                ctrl->val = read_reg(client, TW2804_REG_RED_BALANCE, 0);
                return 0;
        }
        return 0;
}

static int tw2804_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct tw2804 *state = to_state_from_ctrl(ctrl);
        struct i2c_client *client = v4l2_get_subdevdata(&state->sd);
        int addr;
        int reg;

        switch (ctrl->id) {
        case V4L2_CID_AUTOGAIN:
                addr = TW2804_REG_AUTOGAIN;
                reg = read_reg(client, addr, state->channel);
                if (reg < 0)
                        return reg;
                if (ctrl->val == 0)
                        reg &= ~(1 << 7);
                else
                        reg |= 1 << 7;
                return write_reg(client, addr, reg, state->channel);

        case V4L2_CID_COLOR_KILLER:
                addr = TW2804_REG_COLOR_KILLER;
                reg = read_reg(client, addr, state->channel);
                if (reg < 0)
                        return reg;
                reg = (reg & ~(0x03)) | (ctrl->val == 0 ? 0x02 : 0x03);
                return write_reg(client, addr, reg, state->channel);

        case V4L2_CID_GAIN:
                return write_reg(client, TW2804_REG_GAIN, ctrl->val, 0);

        case V4L2_CID_CHROMA_GAIN:
                return write_reg(client, TW2804_REG_CHROMA_GAIN, ctrl->val, 0);

        case V4L2_CID_BLUE_BALANCE:
                return write_reg(client, TW2804_REG_BLUE_BALANCE, ctrl->val, 0);

        case V4L2_CID_RED_BALANCE:
                return write_reg(client, TW2804_REG_RED_BALANCE, ctrl->val, 0);

        case V4L2_CID_BRIGHTNESS:
                return write_reg(client, TW2804_REG_BRIGHTNESS,
                                ctrl->val, state->channel);

        case V4L2_CID_CONTRAST:
                return write_reg(client, TW2804_REG_CONTRAST,
                                ctrl->val, state->channel);

        case V4L2_CID_SATURATION:
                return write_reg(client, TW2804_REG_SATURATION,
                                ctrl->val, state->channel);

        case V4L2_CID_HUE:
                return write_reg(client, TW2804_REG_HUE,
                                ctrl->val, state->channel);

        default:
                break;
        }
        return -EINVAL;
}

static int tw2804_s_std(struct v4l2_subdev *sd, v4l2_std_id norm)
{
        struct tw2804 *dec = to_state(sd);
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        bool is_60hz = norm & V4L2_STD_525_60;
        u8 regs[] = {
                0x01, is_60hz ? 0xc4 : 0x84,
                0x09, is_60hz ? 0x07 : 0x04,
                0x0a, is_60hz ? 0xf0 : 0x20,
                0x0b, is_60hz ? 0x07 : 0x04,
                0x0c, is_60hz ? 0xf0 : 0x20,
                0x0d, is_60hz ? 0x40 : 0x4a,
                0x16, is_60hz ? 0x00 : 0x40,
                0x17, is_60hz ? 0x00 : 0x40,
                0x20, is_60hz ? 0x07 : 0x0f,
                0x21, is_60hz ? 0x07 : 0x0f,
                0xff, 0xff,
        };

        write_regs(client, regs, dec->channel);
        dec->norm = norm;
        return 0;
}

static int tw2804_s_video_routing(struct v4l2_subdev *sd, u32 input, u32 output,
        u32 config)
{
        struct tw2804 *dec = to_state(sd);
        struct i2c_client *client = v4l2_get_subdevdata(sd);
        int reg;

        if (config && config - 1 != dec->channel) {
                if (config > 4) {
                        dev_err(&client->dev,
                                "channel %d is not between 1 and 4!\n", config);
                        return -EINVAL;
                }
                dec->channel = config - 1;
                dev_dbg(&client->dev, "initializing TW2804 channel %d\n",
                        dec->channel);
                if (dec->channel == 0 &&
                                write_regs(client, global_registers, 0) < 0) {
                        dev_err(&client->dev,
                                "error initializing TW2804 global registers\n");
                        return -EIO;
                }
                if (write_regs(client, channel_registers, dec->channel) < 0) {
                        dev_err(&client->dev,
                                "error initializing TW2804 channel %d\n",
                                dec->channel);
                        return -EIO;
                }
        }

        if (input > 1)
                return -EINVAL;

        if (input == dec->input)
                return 0;

        reg = read_reg(client, 0x22, dec->channel);

        if (reg >= 0) {
                if (input == 0)
                        reg &= ~(1 << 2);
                else
                        reg |= 1 << 2;
                reg = write_reg(client, 0x22, reg, dec->channel);
        }

        if (reg >= 0)
                dec->input = input;
        else
                return reg;
        return 0;
}

static const struct v4l2_ctrl_ops tw2804_ctrl_ops = {
        .g_volatile_ctrl = tw2804_g_volatile_ctrl,
        .s_ctrl = tw2804_s_ctrl,
};

static const struct v4l2_subdev_video_ops tw2804_video_ops = {
        .s_std = tw2804_s_std,
        .s_routing = tw2804_s_video_routing,
};

static const struct v4l2_subdev_core_ops tw2804_core_ops = {
        .log_status = tw2804_log_status,
};

static const struct v4l2_subdev_ops tw2804_ops = {
        .core = &tw2804_core_ops,
        .video = &tw2804_video_ops,
};

static int tw2804_probe(struct i2c_client *client)
{
        struct i2c_adapter *adapter = client->adapter;
        struct tw2804 *state;
        struct v4l2_subdev *sd;
        struct v4l2_ctrl *ctrl;
        int err;

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                return -ENODEV;

        state = devm_kzalloc(&client->dev, sizeof(*state), GFP_KERNEL);
        if (state == NULL)
                return -ENOMEM;
        sd = &state->sd;
        v4l2_i2c_subdev_init(sd, client, &tw2804_ops);
        state->channel = -1;
        state->norm = V4L2_STD_NTSC;

        v4l2_ctrl_handler_init(&state->hdl, 10);
        v4l2_ctrl_new_std(&state->hdl, &tw2804_ctrl_ops,
                                V4L2_CID_BRIGHTNESS, 0, 255, 1, 128);
        v4l2_ctrl_new_std(&state->hdl, &tw2804_ctrl_ops,
                                V4L2_CID_CONTRAST, 0, 255, 1, 128);
        v4l2_ctrl_new_std(&state->hdl, &tw2804_ctrl_ops,
                                V4L2_CID_SATURATION, 0, 255, 1, 128);
        v4l2_ctrl_new_std(&state->hdl, &tw2804_ctrl_ops,
                                V4L2_CID_HUE, 0, 255, 1, 128);
        v4l2_ctrl_new_std(&state->hdl, &tw2804_ctrl_ops,
                                V4L2_CID_COLOR_KILLER, 0, 1, 1, 0);
        v4l2_ctrl_new_std(&state->hdl, &tw2804_ctrl_ops,
                                V4L2_CID_AUTOGAIN, 0, 1, 1, 0);
        ctrl = v4l2_ctrl_new_std(&state->hdl, &tw2804_ctrl_ops,
                                V4L2_CID_GAIN, 0, 255, 1, 128);
        if (ctrl)
                ctrl->flags |= V4L2_CTRL_FLAG_VOLATILE;
        ctrl = v4l2_ctrl_new_std(&state->hdl, &tw2804_ctrl_ops,
                                V4L2_CID_CHROMA_GAIN, 0, 255, 1, 128);
        if (ctrl)
                ctrl->flags |= V4L2_CTRL_FLAG_VOLATILE;
        ctrl = v4l2_ctrl_new_std(&state->hdl, &tw2804_ctrl_ops,
                                V4L2_CID_BLUE_BALANCE, 0, 255, 1, 122);
        if (ctrl)
                ctrl->flags |= V4L2_CTRL_FLAG_VOLATILE;
        ctrl = v4l2_ctrl_new_std(&state->hdl, &tw2804_ctrl_ops,
                                V4L2_CID_RED_BALANCE, 0, 255, 1, 122);
        if (ctrl)
                ctrl->flags |= V4L2_CTRL_FLAG_VOLATILE;
        sd->ctrl_handler = &state->hdl;
        err = state->hdl.error;
        if (err) {
                v4l2_ctrl_handler_free(&state->hdl);
                return err;
        }

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

        return 0;
}

static void tw2804_remove(struct i2c_client *client)
{
        struct v4l2_subdev *sd = i2c_get_clientdata(client);
        struct tw2804 *state = to_state(sd);

        v4l2_device_unregister_subdev(sd);
        v4l2_ctrl_handler_free(&state->hdl);
}

static const struct i2c_device_id tw2804_id[] = {
        { "tw2804" },
        { }
};
MODULE_DEVICE_TABLE(i2c, tw2804_id);

static struct i2c_driver tw2804_driver = {
        .driver = {
                .name   = "tw2804",
        },
        .probe          = tw2804_probe,
        .remove         = tw2804_remove,
        .id_table       = tw2804_id,
};

module_i2c_driver(tw2804_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("TW2804/TW2802 V4L2 i2c driver");
MODULE_AUTHOR("Micronas USA Inc");