/*
 * Copyright (C) 2005-2006 Micronas USA Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License (Version 2) as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#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-device.h>
#include <media/v4l2-ctrls.h>

MODULE_DESCRIPTION("TW9906 I2C subdev driver");
MODULE_LICENSE("GPL v2");

struct tw9906 {
        struct v4l2_subdev sd;
        struct v4l2_ctrl_handler hdl;
        v4l2_std_id norm;
};

static inline struct tw9906 *to_state(struct v4l2_subdev *sd)
{
        return container_of(sd, struct tw9906, sd);
}

static const u8 initial_registers[] = {
        0x02, 0x40, /* input 0, composite */
        0x03, 0xa2, /* correct digital format */
        0x05, 0x81, /* or 0x01 for PAL */
        0x07, 0x02, /* window */
        0x08, 0x14, /* window */
        0x09, 0xf0, /* window */
        0x0a, 0x10, /* window */
        0x0b, 0xd0, /* window */
        0x0d, 0x00, /* scaling */
        0x0e, 0x11, /* scaling */
        0x0f, 0x00, /* scaling */
        0x10, 0x00, /* brightness */
        0x11, 0x60, /* contrast */
        0x12, 0x11, /* sharpness */
        0x13, 0x7e, /* U gain */
        0x14, 0x7e, /* V gain */
        0x15, 0x00, /* hue */
        0x19, 0x57, /* vbi */
        0x1a, 0x0f,
        0x1b, 0x40,
        0x29, 0x03,
        0x55, 0x00,
        0x6b, 0x26,
        0x6c, 0x36,
        0x6d, 0xf0,
        0x6e, 0x41,
        0x6f, 0x13,
        0xad, 0x70,
        0x00, 0x00, /* Terminator (reg 0x00 is read-only) */
};

static int write_reg(struct v4l2_subdev *sd, u8 reg, u8 value)
{
        struct i2c_client *client = v4l2_get_subdevdata(sd);

        return i2c_smbus_write_byte_data(client, reg, value);
}

static int write_regs(struct v4l2_subdev *sd, const u8 *regs)
{
        int i;

        for (i = 0; regs[i] != 0x00; i += 2)
                if (write_reg(sd, regs[i], regs[i + 1]) < 0)
                        return -1;
        return 0;
}

static int tw9906_s_video_routing(struct v4l2_subdev *sd, u32 input,
                                      u32 output, u32 config)
{
        write_reg(sd, 0x02, 0x40 | (input << 1));
        return 0;
}

static int tw9906_s_std(struct v4l2_subdev *sd, v4l2_std_id norm)
{
        struct tw9906 *dec = to_state(sd);
        bool is_60hz = norm & V4L2_STD_525_60;
        static const u8 config_60hz[] = {
                0x05, 0x81,
                0x07, 0x02,
                0x08, 0x14,
                0x09, 0xf0,
                0,    0,
        };
        static const u8 config_50hz[] = {
                0x05, 0x01,
                0x07, 0x12,
                0x08, 0x18,
                0x09, 0x20,
                0,    0,
        };

        write_regs(sd, is_60hz ? config_60hz : config_50hz);
        dec->norm = norm;
        return 0;
}

static int tw9906_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct tw9906 *dec = container_of(ctrl->handler, struct tw9906, hdl);
        struct v4l2_subdev *sd = &dec->sd;

        switch (ctrl->id) {
        case V4L2_CID_BRIGHTNESS:
                write_reg(sd, 0x10, ctrl->val);
                break;
        case V4L2_CID_CONTRAST:
                write_reg(sd, 0x11, ctrl->val);
                break;
        case V4L2_CID_HUE:
                write_reg(sd, 0x15, ctrl->val);
                break;
        default:
                return -EINVAL;
        }
        return 0;
}

static int tw9906_log_status(struct v4l2_subdev *sd)
{
        struct tw9906 *dec = to_state(sd);
        bool is_60hz = dec->norm & V4L2_STD_525_60;

        v4l2_info(sd, "Standard: %d Hz\n", is_60hz ? 60 : 50);
        v4l2_ctrl_subdev_log_status(sd);
        return 0;
}

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

static const struct v4l2_ctrl_ops tw9906_ctrl_ops = {
        .s_ctrl = tw9906_s_ctrl,
};

static const struct v4l2_subdev_core_ops tw9906_core_ops = {
        .log_status = tw9906_log_status,
};

static const struct v4l2_subdev_video_ops tw9906_video_ops = {
        .s_std = tw9906_s_std,
        .s_routing = tw9906_s_video_routing,
};

static const struct v4l2_subdev_ops tw9906_ops = {
        .core = &tw9906_core_ops,
        .video = &tw9906_video_ops,
};

static int tw9906_probe(struct i2c_client *client,
                             const struct i2c_device_id *id)
{
        struct tw9906 *dec;
        struct v4l2_subdev *sd;
        struct v4l2_ctrl_handler *hdl;

        /* Check if the adapter supports the needed features */
        if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                return -EIO;

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

        dec = devm_kzalloc(&client->dev, sizeof(*dec), GFP_KERNEL);
        if (dec == NULL)
                return -ENOMEM;
        sd = &dec->sd;
        v4l2_i2c_subdev_init(sd, client, &tw9906_ops);
        hdl = &dec->hdl;
        v4l2_ctrl_handler_init(hdl, 4);
        v4l2_ctrl_new_std(hdl, &tw9906_ctrl_ops,
                V4L2_CID_BRIGHTNESS, -128, 127, 1, 0);
        v4l2_ctrl_new_std(hdl, &tw9906_ctrl_ops,
                V4L2_CID_CONTRAST, 0, 255, 1, 0x60);
        v4l2_ctrl_new_std(hdl, &tw9906_ctrl_ops,
                V4L2_CID_HUE, -128, 127, 1, 0);
        sd->ctrl_handler = hdl;
        if (hdl->error) {
                int err = hdl->error;

                v4l2_ctrl_handler_free(hdl);
                return err;
        }

        /* Initialize tw9906 */
        dec->norm = V4L2_STD_NTSC;

        if (write_regs(sd, initial_registers) < 0) {
                v4l2_err(client, "error initializing TW9906\n");
                return -EINVAL;
        }

        return 0;
}

static int tw9906_remove(struct i2c_client *client)
{
        struct v4l2_subdev *sd = i2c_get_clientdata(client);

        v4l2_device_unregister_subdev(sd);
        v4l2_ctrl_handler_free(&to_state(sd)->hdl);
        return 0;
}

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

static const struct i2c_device_id tw9906_id[] = {
        { "tw9906", 0 },
        { }
};
MODULE_DEVICE_TABLE(i2c, tw9906_id);

static struct i2c_driver tw9906_driver = {
        .driver = {
                .name   = "tw9906",
        },
        .probe = tw9906_probe,
        .remove = tw9906_remove,
        .id_table = tw9906_id,
};
module_i2c_driver(tw9906_driver);