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

MODULE_DESCRIPTION("TW9903 I2C subdev driver");
MODULE_LICENSE("GPL v2");

/*
 * This driver is based on the wis-tw9903.c source that was in
 * drivers/staging/media/go7007. That source had commented out code for
 * saturation and scaling (neither seemed to work). If anyone ever gets
 * hardware to test this driver, then that code might be useful to look at.
 * You need to get the kernel sources of, say, kernel 3.8 where that
 * wis-tw9903 driver is still present.
 */

struct tw9903 {
        struct v4l2_subdev sd;
        struct v4l2_ctrl_handler hdl;
        v4l2_std_id norm;
};

static inline struct tw9903 *to_state(struct v4l2_subdev *sd)
{
        return container_of(sd, struct tw9903, sd);
}

static const u8 initial_registers[] = {
        0x02, 0x44, /* input 1, composite */
        0x03, 0x92, /* correct digital format */
        0x04, 0x00,
        0x05, 0x80, /* or 0x00 for PAL */
        0x06, 0x40, /* second internal current reference */
        0x07, 0x02, /* window */
        0x08, 0x14, /* window */
        0x09, 0xf0, /* window */
        0x0a, 0x81, /* window */
        0x0b, 0xd0, /* window */
        0x0c, 0x8c,
        0x0d, 0x00, /* scaling */
        0x0e, 0x11, /* scaling */
        0x0f, 0x00, /* scaling */
        0x10, 0x00, /* brightness */
        0x11, 0x60, /* contrast */
        0x12, 0x01, /* sharpness */
        0x13, 0x7f, /* U gain */
        0x14, 0x5a, /* V gain */
        0x15, 0x00, /* hue */
        0x16, 0xc3, /* sharpness */
        0x18, 0x00,
        0x19, 0x58, /* vbi */
        0x1a, 0x80,
        0x1c, 0x0f, /* video norm */
        0x1d, 0x7f, /* video norm */
        0x20, 0xa0, /* clamping gain (working 0x50) */
        0x21, 0x22,
        0x22, 0xf0,
        0x23, 0xfe,
        0x24, 0x3c,
        0x25, 0x38,
        0x26, 0x44,
        0x27, 0x20,
        0x28, 0x00,
        0x29, 0x15,
        0x2a, 0xa0,
        0x2b, 0x44,
        0x2c, 0x37,
        0x2d, 0x00,
        0x2e, 0xa5, /* burst PLL control (working: a9) */
        0x2f, 0xe0, /* 0xea is blue test frame -- 0xe0 for normal */
        0x31, 0x00,
        0x33, 0x22,
        0x34, 0x11,
        0x35, 0x35,
        0x3b, 0x05,
        0x06, 0xc0, /* reset device */
        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 tw9903_s_video_routing(struct v4l2_subdev *sd, u32 input,
                                      u32 output, u32 config)
{
        write_reg(sd, 0x02, 0x40 | (input << 1));
        return 0;
}

static int tw9903_s_std(struct v4l2_subdev *sd, v4l2_std_id norm)
{
        struct tw9903 *dec = to_state(sd);
        bool is_60hz = norm & V4L2_STD_525_60;
        static const u8 config_60hz[] = {
                0x05, 0x80,
                0x07, 0x02,
                0x08, 0x14,
                0x09, 0xf0,
                0,    0,
        };
        static const u8 config_50hz[] = {
                0x05, 0x00,
                0x07, 0x12,
                0x08, 0x18,
                0x09, 0x20,
                0,    0,
        };

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


static int tw9903_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct tw9903 *dec = container_of(ctrl->handler, struct tw9903, 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 tw9903_log_status(struct v4l2_subdev *sd)
{
        struct tw9903 *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 tw9903_ctrl_ops = {
        .s_ctrl = tw9903_s_ctrl,
};

static const struct v4l2_subdev_core_ops tw9903_core_ops = {
        .log_status = tw9903_log_status,
};

static const struct v4l2_subdev_video_ops tw9903_video_ops = {
        .s_std = tw9903_s_std,
        .s_routing = tw9903_s_video_routing,
};

static const struct v4l2_subdev_ops tw9903_ops = {
        .core = &tw9903_core_ops,
        .video = &tw9903_video_ops,
};

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

static int tw9903_probe(struct i2c_client *client,
                             const struct i2c_device_id *id)
{
        struct tw9903 *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, &tw9903_ops);
        hdl = &dec->hdl;
        v4l2_ctrl_handler_init(hdl, 4);
        v4l2_ctrl_new_std(hdl, &tw9903_ctrl_ops,
                V4L2_CID_BRIGHTNESS, -128, 127, 1, 0);
        v4l2_ctrl_new_std(hdl, &tw9903_ctrl_ops,
                V4L2_CID_CONTRAST, 0, 255, 1, 0x60);
        v4l2_ctrl_new_std(hdl, &tw9903_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 tw9903 */
        dec->norm = V4L2_STD_NTSC;

        if (write_regs(sd, initial_registers) < 0) {
                v4l2_err(client, "error initializing TW9903\n");
                return -EINVAL;
        }

        return 0;
}

static int tw9903_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 tw9903_id[] = {
        { "tw9903", 0 },
        { }
};
MODULE_DEVICE_TABLE(i2c, tw9903_id);

static struct i2c_driver tw9903_driver = {
        .driver = {
                .name   = "tw9903",
        },
        .probe = tw9903_probe,
        .remove = tw9903_remove,
        .id_table = tw9903_id,
};
module_i2c_driver(tw9903_driver);