/*
 * 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-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,
			    const struct i2c_device_id *id)
{
	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 int 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);
	return 0;
}

static const struct i2c_device_id tw2804_id[] = {
	{ "tw2804", 0 },
	{ }
};
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");