/* cx25840 - Conexant CX25840 audio/video decoder driver
 *
 * Copyright (C) 2004 Ulf Eklund
 *
 * Based on the saa7115 driver and on the first verison of Chris Kennedy's
 * cx25840 driver.
 *
 * Changes by Tyler Trafford <tatrafford@comcast.net>
 *    - cleanup/rewrite for V4L2 API (2005)
 *
 * VBI support by Hans Verkuil <hverkuil@xs4all.nl>.
 *
 * NTSC sliced VBI support by Christopher Neufeld <television@cneufeld.ca>
 * with additional fixes by Hans Verkuil <hverkuil@xs4all.nl>.
 *
 * CX23885 support by Steven Toth <stoth@linuxtv.org>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */


#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/videodev2.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <media/v4l2-common.h>
#include <media/v4l2-chip-ident.h>
#include <media/v4l2-i2c-drv.h>
#include <media/cx25840.h>

#include "cx25840-core.h"

MODULE_DESCRIPTION("Conexant CX25840 audio/video decoder driver");
MODULE_AUTHOR("Ulf Eklund, Chris Kennedy, Hans Verkuil, Tyler Trafford");
MODULE_LICENSE("GPL");

static int cx25840_debug;

module_param_named(debug,cx25840_debug, int, 0644);

MODULE_PARM_DESC(debug, "Debugging messages [0=Off (default) 1=On]");


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

int cx25840_write(struct i2c_client *client, u16 addr, u8 value)
{
	u8 buffer[3];
	buffer[0] = addr >> 8;
	buffer[1] = addr & 0xff;
	buffer[2] = value;
	return i2c_master_send(client, buffer, 3);
}

int cx25840_write4(struct i2c_client *client, u16 addr, u32 value)
{
	u8 buffer[6];
	buffer[0] = addr >> 8;
	buffer[1] = addr & 0xff;
	buffer[2] = value & 0xff;
	buffer[3] = (value >> 8) & 0xff;
	buffer[4] = (value >> 16) & 0xff;
	buffer[5] = value >> 24;
	return i2c_master_send(client, buffer, 6);
}

u8 cx25840_read(struct i2c_client * client, u16 addr)
{
	u8 buffer[2];
	buffer[0] = addr >> 8;
	buffer[1] = addr & 0xff;

	if (i2c_master_send(client, buffer, 2) < 2)
		return 0;

	if (i2c_master_recv(client, buffer, 1) < 1)
		return 0;

	return buffer[0];
}

u32 cx25840_read4(struct i2c_client * client, u16 addr)
{
	u8 buffer[4];
	buffer[0] = addr >> 8;
	buffer[1] = addr & 0xff;

	if (i2c_master_send(client, buffer, 2) < 2)
		return 0;

	if (i2c_master_recv(client, buffer, 4) < 4)
		return 0;

	return (buffer[3] << 24) | (buffer[2] << 16) |
	    (buffer[1] << 8) | buffer[0];
}

int cx25840_and_or(struct i2c_client *client, u16 addr, unsigned and_mask,
		   u8 or_value)
{
	return cx25840_write(client, addr,
			     (cx25840_read(client, addr) & and_mask) |
			     or_value);
}

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

static int set_input(struct i2c_client *client, enum cx25840_video_input vid_input,
						enum cx25840_audio_input aud_input);

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

static void init_dll1(struct i2c_client *client)
{
	/* This is the Hauppauge sequence used to
	 * initialize the Delay Lock Loop 1 (ADC DLL). */
	cx25840_write(client, 0x159, 0x23);
	cx25840_write(client, 0x15a, 0x87);
	cx25840_write(client, 0x15b, 0x06);
	udelay(10);
	cx25840_write(client, 0x159, 0xe1);
	udelay(10);
	cx25840_write(client, 0x15a, 0x86);
	cx25840_write(client, 0x159, 0xe0);
	cx25840_write(client, 0x159, 0xe1);
	cx25840_write(client, 0x15b, 0x10);
}

static void init_dll2(struct i2c_client *client)
{
	/* This is the Hauppauge sequence used to
	 * initialize the Delay Lock Loop 2 (ADC DLL). */
	cx25840_write(client, 0x15d, 0xe3);
	cx25840_write(client, 0x15e, 0x86);
	cx25840_write(client, 0x15f, 0x06);
	udelay(10);
	cx25840_write(client, 0x15d, 0xe1);
	cx25840_write(client, 0x15d, 0xe0);
	cx25840_write(client, 0x15d, 0xe1);
}

static void cx25836_initialize(struct i2c_client *client)
{
	/* reset configuration is described on page 3-77 of the CX25836 datasheet */
	/* 2. */
	cx25840_and_or(client, 0x000, ~0x01, 0x01);
	cx25840_and_or(client, 0x000, ~0x01, 0x00);
	/* 3a. */
	cx25840_and_or(client, 0x15a, ~0x70, 0x00);
	/* 3b. */
	cx25840_and_or(client, 0x15b, ~0x1e, 0x06);
	/* 3c. */
	cx25840_and_or(client, 0x159, ~0x02, 0x02);
	/* 3d. */
	udelay(10);
	/* 3e. */
	cx25840_and_or(client, 0x159, ~0x02, 0x00);
	/* 3f. */
	cx25840_and_or(client, 0x159, ~0xc0, 0xc0);
	/* 3g. */
	cx25840_and_or(client, 0x159, ~0x01, 0x00);
	cx25840_and_or(client, 0x159, ~0x01, 0x01);
	/* 3h. */
	cx25840_and_or(client, 0x15b, ~0x1e, 0x10);
}

static void cx25840_work_handler(struct work_struct *work)
{
	struct cx25840_state *state = container_of(work, struct cx25840_state, fw_work);
	cx25840_loadfw(state->c);
	wake_up(&state->fw_wait);
}

static void cx25840_initialize(struct i2c_client *client)
{
	DEFINE_WAIT(wait);
	struct cx25840_state *state = to_state(i2c_get_clientdata(client));
	struct workqueue_struct *q;

	/* datasheet startup in numbered steps, refer to page 3-77 */
	/* 2. */
	cx25840_and_or(client, 0x803, ~0x10, 0x00);
	/* The default of this register should be 4, but I get 0 instead.
	 * Set this register to 4 manually. */
	cx25840_write(client, 0x000, 0x04);
	/* 3. */
	init_dll1(client);
	init_dll2(client);
	cx25840_write(client, 0x136, 0x0a);
	/* 4. */
	cx25840_write(client, 0x13c, 0x01);
	cx25840_write(client, 0x13c, 0x00);
	/* 5. */
	/* Do the firmware load in a work handler to prevent.
	   Otherwise the kernel is blocked waiting for the
	   bit-banging i2c interface to finish uploading the
	   firmware. */
	INIT_WORK(&state->fw_work, cx25840_work_handler);
	init_waitqueue_head(&state->fw_wait);
	q = create_singlethread_workqueue("cx25840_fw");
	prepare_to_wait(&state->fw_wait, &wait, TASK_UNINTERRUPTIBLE);
	queue_work(q, &state->fw_work);
	schedule();
	finish_wait(&state->fw_wait, &wait);
	destroy_workqueue(q);

	/* 6. */
	cx25840_write(client, 0x115, 0x8c);
	cx25840_write(client, 0x116, 0x07);
	cx25840_write(client, 0x118, 0x02);
	/* 7. */
	cx25840_write(client, 0x4a5, 0x80);
	cx25840_write(client, 0x4a5, 0x00);
	cx25840_write(client, 0x402, 0x00);
	/* 8. */
	cx25840_and_or(client, 0x401, ~0x18, 0);
	cx25840_and_or(client, 0x4a2, ~0x10, 0x10);
	/* steps 8c and 8d are done in change_input() */
	/* 10. */
	cx25840_write(client, 0x8d3, 0x1f);
	cx25840_write(client, 0x8e3, 0x03);

	cx25840_std_setup(client);

	/* trial and error says these are needed to get audio */
	cx25840_write(client, 0x914, 0xa0);
	cx25840_write(client, 0x918, 0xa0);
	cx25840_write(client, 0x919, 0x01);

	/* stereo prefered */
	cx25840_write(client, 0x809, 0x04);
	/* AC97 shift */
	cx25840_write(client, 0x8cf, 0x0f);

	/* (re)set input */
	set_input(client, state->vid_input, state->aud_input);

	/* start microcontroller */
	cx25840_and_or(client, 0x803, ~0x10, 0x10);
}

static void cx23885_initialize(struct i2c_client *client)
{
	DEFINE_WAIT(wait);
	struct cx25840_state *state = to_state(i2c_get_clientdata(client));
	struct workqueue_struct *q;

	/*
	 * Come out of digital power down
	 * The CX23888, at least, needs this, otherwise registers aside from
	 * 0x0-0x2 can't be read or written.
	 */
	cx25840_write(client, 0x000, 0);

	/* Internal Reset */
	cx25840_and_or(client, 0x102, ~0x01, 0x01);
	cx25840_and_or(client, 0x102, ~0x01, 0x00);

	/* Stop microcontroller */
	cx25840_and_or(client, 0x803, ~0x10, 0x00);

	/* DIF in reset? */
	cx25840_write(client, 0x398, 0);

	/*
	 * Trust the default xtal, no division
	 * '885: 28.636363... MHz
	 * '887: 25.000000 MHz
	 * '888: 50.000000 MHz
	 */
	cx25840_write(client, 0x2, 0x76);

	/* Power up all the PLL's and DLL */
	cx25840_write(client, 0x1, 0x40);

	/* Sys PLL */
	switch (state->id) {
	case V4L2_IDENT_CX23888_AV:
		/*
		 * 50.0 MHz * (0xb + 0xe8ba26/0x2000000)/4 = 5 * 28.636363 MHz
		 * 572.73 MHz before post divide
		 */
		cx25840_write4(client, 0x11c, 0x00e8ba26);
		cx25840_write4(client, 0x118, 0x0000040b);
		break;
	case V4L2_IDENT_CX23887_AV:
		/*
		 * 25.0 MHz * (0x16 + 0x1d1744c/0x2000000)/4 = 5 * 28.636363 MHz
		 * 572.73 MHz before post divide
		 */
		cx25840_write4(client, 0x11c, 0x01d1744c);
		cx25840_write4(client, 0x118, 0x00000416);
		break;
	case V4L2_IDENT_CX23885_AV:
	default:
		/*
		 * 28.636363 MHz * (0x14 + 0x0/0x2000000)/4 = 5 * 28.636363 MHz
		 * 572.73 MHz before post divide
		 */
		cx25840_write4(client, 0x11c, 0x00000000);
		cx25840_write4(client, 0x118, 0x00000414);
		break;
	}

	/* Disable DIF bypass */
	cx25840_write4(client, 0x33c, 0x00000001);

	/* DIF Src phase inc */
	cx25840_write4(client, 0x340, 0x0df7df83);

	/*
	 * Vid PLL
	 * Setup for a BT.656 pixel clock of 13.5 Mpixels/second
	 *
	 * 28.636363 MHz * (0xf + 0x02be2c9/0x2000000)/4 = 8 * 13.5 MHz
	 * 432.0 MHz before post divide
	 */
	cx25840_write4(client, 0x10c, 0x002be2c9);
	cx25840_write4(client, 0x108, 0x0000040f);

	/* Luma */
	cx25840_write4(client, 0x414, 0x00107d12);

	/* Chroma */
	cx25840_write4(client, 0x420, 0x3d008282);

	/*
	 * Aux PLL
	 * Initial setup for audio sample clock:
	 * 48 ksps, 16 bits/sample, x160 multiplier = 122.88 MHz
	 * Intial I2S output/master clock(?):
	 * 48 ksps, 16 bits/sample, x16 multiplier = 12.288 MHz
	 */
	switch (state->id) {
	case V4L2_IDENT_CX23888_AV:
		/*
		 * 50.0 MHz * (0x7 + 0x0bedfa4/0x2000000)/3 = 122.88 MHz
		 * 368.64 MHz before post divide
		 * 122.88 MHz / 0xa = 12.288 MHz
		 */
		cx25840_write4(client, 0x114, 0x00bedfa4);
		cx25840_write4(client, 0x110, 0x000a0307);
		break;
	case V4L2_IDENT_CX23887_AV:
		/*
		 * 25.0 MHz * (0xe + 0x17dbf48/0x2000000)/3 = 122.88 MHz
		 * 368.64 MHz before post divide
		 * 122.88 MHz / 0xa = 12.288 MHz
		 */
		cx25840_write4(client, 0x114, 0x017dbf48);
		cx25840_write4(client, 0x110, 0x000a030e);
		break;
	case V4L2_IDENT_CX23885_AV:
	default:
		/*
		 * 28.636363 MHz * (0xc + 0x1bf0c9e/0x2000000)/3 = 122.88 MHz
		 * 368.64 MHz before post divide
		 * 122.88 MHz / 0xa = 12.288 MHz
		 */
		cx25840_write4(client, 0x114, 0x01bf0c9e);
		cx25840_write4(client, 0x110, 0x000a030c);
		break;
	};

	/* ADC2 input select */
	cx25840_write(client, 0x102, 0x10);

	/* VIN1 & VIN5 */
	cx25840_write(client, 0x103, 0x11);

	/* Enable format auto detect */
	cx25840_write(client, 0x400, 0);
	/* Fast subchroma lock */
	/* White crush, Chroma AGC & Chroma Killer enabled */
	cx25840_write(client, 0x401, 0xe8);

	/* Select AFE clock pad output source */
	cx25840_write(client, 0x144, 0x05);

	/* Drive GPIO2 direction and values for HVR1700
	 * where an onboard mux selects the output of demodulator
	 * vs the 417. Failure to set this results in no DTV.
	 * It's safe to set this across all Hauppauge boards
	 * currently, regardless of the board type.
	 */
	cx25840_write(client, 0x160, 0x1d);
	cx25840_write(client, 0x164, 0x00);

	/* Do the firmware load in a work handler to prevent.
	   Otherwise the kernel is blocked waiting for the
	   bit-banging i2c interface to finish uploading the
	   firmware. */
	INIT_WORK(&state->fw_work, cx25840_work_handler);
	init_waitqueue_head(&state->fw_wait);
	q = create_singlethread_workqueue("cx25840_fw");
	prepare_to_wait(&state->fw_wait, &wait, TASK_UNINTERRUPTIBLE);
	queue_work(q, &state->fw_work);
	schedule();
	finish_wait(&state->fw_wait, &wait);
	destroy_workqueue(q);

	cx25840_std_setup(client);

	/* (re)set input */
	set_input(client, state->vid_input, state->aud_input);

	/* start microcontroller */
	cx25840_and_or(client, 0x803, ~0x10, 0x10);
}

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

static void cx231xx_initialize(struct i2c_client *client)
{
	DEFINE_WAIT(wait);
	struct cx25840_state *state = to_state(i2c_get_clientdata(client));
	struct workqueue_struct *q;

	/* Internal Reset */
	cx25840_and_or(client, 0x102, ~0x01, 0x01);
	cx25840_and_or(client, 0x102, ~0x01, 0x00);

	/* Stop microcontroller */
	cx25840_and_or(client, 0x803, ~0x10, 0x00);

	/* DIF in reset? */
	cx25840_write(client, 0x398, 0);

	/* Trust the default xtal, no division */
	/* This changes for the cx23888 products */
	cx25840_write(client, 0x2, 0x76);

	/* Bring down the regulator for AUX clk */
	cx25840_write(client, 0x1, 0x40);

	/* Disable DIF bypass */
	cx25840_write4(client, 0x33c, 0x00000001);

	/* DIF Src phase inc */
	cx25840_write4(client, 0x340, 0x0df7df83);

	/* Luma */
	cx25840_write4(client, 0x414, 0x00107d12);

	/* Chroma */
	cx25840_write4(client, 0x420, 0x3d008282);

	/* ADC2 input select */
	cx25840_write(client, 0x102, 0x10);

	/* VIN1 & VIN5 */
	cx25840_write(client, 0x103, 0x11);

	/* Enable format auto detect */
	cx25840_write(client, 0x400, 0);
	/* Fast subchroma lock */
	/* White crush, Chroma AGC & Chroma Killer enabled */
	cx25840_write(client, 0x401, 0xe8);

	/* Do the firmware load in a work handler to prevent.
	   Otherwise the kernel is blocked waiting for the
	   bit-banging i2c interface to finish uploading the
	   firmware. */
	INIT_WORK(&state->fw_work, cx25840_work_handler);
	init_waitqueue_head(&state->fw_wait);
	q = create_singlethread_workqueue("cx25840_fw");
	prepare_to_wait(&state->fw_wait, &wait, TASK_UNINTERRUPTIBLE);
	queue_work(q, &state->fw_work);
	schedule();
	finish_wait(&state->fw_wait, &wait);
	destroy_workqueue(q);

	cx25840_std_setup(client);

	/* (re)set input */
	set_input(client, state->vid_input, state->aud_input);

	/* start microcontroller */
	cx25840_and_or(client, 0x803, ~0x10, 0x10);
}

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

void cx25840_std_setup(struct i2c_client *client)
{
	struct cx25840_state *state = to_state(i2c_get_clientdata(client));
	v4l2_std_id std = state->std;
	int hblank, hactive, burst, vblank, vactive, sc;
	int vblank656, src_decimation;
	int luma_lpf, uv_lpf, comb;
	u32 pll_int, pll_frac, pll_post;

	/* datasheet startup, step 8d */
	if (std & ~V4L2_STD_NTSC)
		cx25840_write(client, 0x49f, 0x11);
	else
		cx25840_write(client, 0x49f, 0x14);

	if (std & V4L2_STD_625_50) {
		hblank = 132;
		hactive = 720;
		burst = 93;
		vblank = 36;
		vactive = 580;
		vblank656 = 40;
		src_decimation = 0x21f;
		luma_lpf = 2;

		if (std & V4L2_STD_SECAM) {
			uv_lpf = 0;
			comb = 0;
			sc = 0x0a425f;
		} else if (std == V4L2_STD_PAL_Nc) {
			uv_lpf = 1;
			comb = 0x20;
			sc = 556453;
		} else {
			uv_lpf = 1;
			comb = 0x20;
			sc = 688739;
		}
	} else {
		hactive = 720;
		hblank = 122;
		vactive = 487;
		luma_lpf = 1;
		uv_lpf = 1;

		src_decimation = 0x21f;
		if (std == V4L2_STD_PAL_60) {
			vblank = 26;
			vblank656 = 26;
			burst = 0x5b;
			luma_lpf = 2;
			comb = 0x20;
			sc = 688739;
		} else if (std == V4L2_STD_PAL_M) {
			vblank = 20;
			vblank656 = 24;
			burst = 0x61;
			comb = 0x20;
			sc = 555452;
		} else {
			vblank = 26;
			vblank656 = 26;
			burst = 0x5b;
			comb = 0x66;
			sc = 556063;
		}
	}

	/* DEBUG: Displays configured PLL frequency */
	if (!is_cx231xx(state)) {
		pll_int = cx25840_read(client, 0x108);
		pll_frac = cx25840_read4(client, 0x10c) & 0x1ffffff;
		pll_post = cx25840_read(client, 0x109);
		v4l_dbg(1, cx25840_debug, client,
			"PLL regs = int: %u, frac: %u, post: %u\n",
			pll_int, pll_frac, pll_post);

		if (pll_post) {
			int fin, fsc;
			int pll = (28636363L * ((((u64)pll_int) << 25L) + pll_frac)) >> 25L;

			pll /= pll_post;
			v4l_dbg(1, cx25840_debug, client, "PLL = %d.%06d MHz\n",
					pll / 1000000, pll % 1000000);
			v4l_dbg(1, cx25840_debug, client, "PLL/8 = %d.%06d MHz\n",
					pll / 8000000, (pll / 8) % 1000000);

			fin = ((u64)src_decimation * pll) >> 12;
			v4l_dbg(1, cx25840_debug, client,
					"ADC Sampling freq = %d.%06d MHz\n",
					fin / 1000000, fin % 1000000);

			fsc = (((u64)sc) * pll) >> 24L;
			v4l_dbg(1, cx25840_debug, client,
					"Chroma sub-carrier freq = %d.%06d MHz\n",
					fsc / 1000000, fsc % 1000000);

			v4l_dbg(1, cx25840_debug, client, "hblank %i, hactive %i, "
				"vblank %i, vactive %i, vblank656 %i, src_dec %i, "
				"burst 0x%02x, luma_lpf %i, uv_lpf %i, comb 0x%02x, "
				"sc 0x%06x\n",
				hblank, hactive, vblank, vactive, vblank656,
				src_decimation, burst, luma_lpf, uv_lpf, comb, sc);
		}
	}

	/* Sets horizontal blanking delay and active lines */
	cx25840_write(client, 0x470, hblank);
	cx25840_write(client, 0x471,
			0xff & (((hblank >> 8) & 0x3) | (hactive << 4)));
	cx25840_write(client, 0x472, hactive >> 4);

	/* Sets burst gate delay */
	cx25840_write(client, 0x473, burst);

	/* Sets vertical blanking delay and active duration */
	cx25840_write(client, 0x474, vblank);
	cx25840_write(client, 0x475,
			0xff & (((vblank >> 8) & 0x3) | (vactive << 4)));
	cx25840_write(client, 0x476, vactive >> 4);
	cx25840_write(client, 0x477, vblank656);

	/* Sets src decimation rate */
	cx25840_write(client, 0x478, 0xff & src_decimation);
	cx25840_write(client, 0x479, 0xff & (src_decimation >> 8));

	/* Sets Luma and UV Low pass filters */
	cx25840_write(client, 0x47a, luma_lpf << 6 | ((uv_lpf << 4) & 0x30));

	/* Enables comb filters */
	cx25840_write(client, 0x47b, comb);

	/* Sets SC Step*/
	cx25840_write(client, 0x47c, sc);
	cx25840_write(client, 0x47d, 0xff & sc >> 8);
	cx25840_write(client, 0x47e, 0xff & sc >> 16);

	/* Sets VBI parameters */
	if (std & V4L2_STD_625_50) {
		cx25840_write(client, 0x47f, 0x01);
		state->vbi_line_offset = 5;
	} else {
		cx25840_write(client, 0x47f, 0x00);
		state->vbi_line_offset = 8;
	}
}

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

static void input_change(struct i2c_client *client)
{
	struct cx25840_state *state = to_state(i2c_get_clientdata(client));
	v4l2_std_id std = state->std;

	/* Follow step 8c and 8d of section 3.16 in the cx25840 datasheet */
	if (std & V4L2_STD_SECAM) {
		cx25840_write(client, 0x402, 0);
	}
	else {
		cx25840_write(client, 0x402, 0x04);
		cx25840_write(client, 0x49f, (std & V4L2_STD_NTSC) ? 0x14 : 0x11);
	}
	cx25840_and_or(client, 0x401, ~0x60, 0);
	cx25840_and_or(client, 0x401, ~0x60, 0x60);
	cx25840_and_or(client, 0x810, ~0x01, 1);

	if (state->radio) {
		cx25840_write(client, 0x808, 0xf9);
		cx25840_write(client, 0x80b, 0x00);
	}
	else if (std & V4L2_STD_525_60) {
		/* Certain Hauppauge PVR150 models have a hardware bug
		   that causes audio to drop out. For these models the
		   audio standard must be set explicitly.
		   To be precise: it affects cards with tuner models
		   85, 99 and 112 (model numbers from tveeprom). */
		int hw_fix = state->pvr150_workaround;

		if (std == V4L2_STD_NTSC_M_JP) {
			/* Japan uses EIAJ audio standard */
			cx25840_write(client, 0x808, hw_fix ? 0x2f : 0xf7);
		} else if (std == V4L2_STD_NTSC_M_KR) {
			/* South Korea uses A2 audio standard */
			cx25840_write(client, 0x808, hw_fix ? 0x3f : 0xf8);
		} else {
			/* Others use the BTSC audio standard */
			cx25840_write(client, 0x808, hw_fix ? 0x1f : 0xf6);
		}
		cx25840_write(client, 0x80b, 0x00);
	} else if (std & V4L2_STD_PAL) {
		/* Autodetect audio standard and audio system */
		cx25840_write(client, 0x808, 0xff);
		/* Since system PAL-L is pretty much non-existant and
		   not used by any public broadcast network, force
		   6.5 MHz carrier to be interpreted as System DK,
		   this avoids DK audio detection instability */
	       cx25840_write(client, 0x80b, 0x00);
	} else if (std & V4L2_STD_SECAM) {
		/* Autodetect audio standard and audio system */
		cx25840_write(client, 0x808, 0xff);
		/* If only one of SECAM-DK / SECAM-L is required, then force
		  6.5MHz carrier, else autodetect it */
		if ((std & V4L2_STD_SECAM_DK) &&
		    !(std & (V4L2_STD_SECAM_L | V4L2_STD_SECAM_LC))) {
			/* 6.5 MHz carrier to be interpreted as System DK */
			cx25840_write(client, 0x80b, 0x00);
	       } else if (!(std & V4L2_STD_SECAM_DK) &&
			  (std & (V4L2_STD_SECAM_L | V4L2_STD_SECAM_LC))) {
			/* 6.5 MHz carrier to be interpreted as System L */
			cx25840_write(client, 0x80b, 0x08);
	       } else {
			/* 6.5 MHz carrier to be autodetected */
			cx25840_write(client, 0x80b, 0x10);
	       }
	}

	cx25840_and_or(client, 0x810, ~0x01, 0);
}

static int set_input(struct i2c_client *client, enum cx25840_video_input vid_input,
						enum cx25840_audio_input aud_input)
{
	struct cx25840_state *state = to_state(i2c_get_clientdata(client));
	u8 is_composite = (vid_input >= CX25840_COMPOSITE1 &&
			   vid_input <= CX25840_COMPOSITE8);
	u8 is_component = (vid_input & CX25840_COMPONENT_ON) ==
			CX25840_COMPONENT_ON;
	int luma = vid_input & 0xf0;
	int chroma = vid_input & 0xf00;
	u8 reg;

	v4l_dbg(1, cx25840_debug, client,
		"decoder set video input %d, audio input %d\n",
		vid_input, aud_input);

	if (vid_input >= CX25840_VIN1_CH1) {
		v4l_dbg(1, cx25840_debug, client, "vid_input 0x%x\n",
			vid_input);
		reg = vid_input & 0xff;
		if ((vid_input & CX25840_SVIDEO_ON) == CX25840_SVIDEO_ON)
			is_composite = 0;
		else if ((vid_input & CX25840_COMPONENT_ON) == 0)
			is_composite = 1;

		v4l_dbg(1, cx25840_debug, client, "mux cfg 0x%x comp=%d\n",
			reg, is_composite);
	} else if (is_composite) {
		reg = 0xf0 + (vid_input - CX25840_COMPOSITE1);
	} else {
		if ((vid_input & ~0xff0) ||
		    luma < CX25840_SVIDEO_LUMA1 || luma > CX25840_SVIDEO_LUMA8 ||
		    chroma < CX25840_SVIDEO_CHROMA4 || chroma > CX25840_SVIDEO_CHROMA8) {
			v4l_err(client, "0x%04x is not a valid video input!\n",
				vid_input);
			return -EINVAL;
		}
		reg = 0xf0 + ((luma - CX25840_SVIDEO_LUMA1) >> 4);
		if (chroma >= CX25840_SVIDEO_CHROMA7) {
			reg &= 0x3f;
			reg |= (chroma - CX25840_SVIDEO_CHROMA7) >> 2;
		} else {
			reg &= 0xcf;
			reg |= (chroma - CX25840_SVIDEO_CHROMA4) >> 4;
		}
	}

	/* The caller has previously prepared the correct routing
	 * configuration in reg (for the cx23885) so we have no
	 * need to attempt to flip bits for earlier av decoders.
	 */
	if (!is_cx2388x(state) && !is_cx231xx(state)) {
		switch (aud_input) {
		case CX25840_AUDIO_SERIAL:
			/* do nothing, use serial audio input */
			break;
		case CX25840_AUDIO4: reg &= ~0x30; break;
		case CX25840_AUDIO5: reg &= ~0x30; reg |= 0x10; break;
		case CX25840_AUDIO6: reg &= ~0x30; reg |= 0x20; break;
		case CX25840_AUDIO7: reg &= ~0xc0; break;
		case CX25840_AUDIO8: reg &= ~0xc0; reg |= 0x40; break;

		default:
			v4l_err(client, "0x%04x is not a valid audio input!\n",
				aud_input);
			return -EINVAL;
		}
	}

	cx25840_write(client, 0x103, reg);

	/* Set INPUT_MODE to Composite, S-Video or Component */
	if (is_component)
		cx25840_and_or(client, 0x401, ~0x6, 0x6);
	else
		cx25840_and_or(client, 0x401, ~0x6, is_composite ? 0 : 0x02);

	if (!is_cx2388x(state) && !is_cx231xx(state)) {
		/* Set CH_SEL_ADC2 to 1 if input comes from CH3 */
		cx25840_and_or(client, 0x102, ~0x2, (reg & 0x80) == 0 ? 2 : 0);
		/* Set DUAL_MODE_ADC2 to 1 if input comes from both CH2&CH3 */
		if ((reg & 0xc0) != 0xc0 && (reg & 0x30) != 0x30)
			cx25840_and_or(client, 0x102, ~0x4, 4);
		else
			cx25840_and_or(client, 0x102, ~0x4, 0);
	} else {
		/* Set DUAL_MODE_ADC2 to 1 if component*/
		cx25840_and_or(client, 0x102, ~0x4, is_component ? 0x4 : 0x0);
		if (is_composite) {
			/* ADC2 input select channel 2 */
			cx25840_and_or(client, 0x102, ~0x2, 0);
		} else if (!is_component) {
			/* S-Video */
			if (chroma >= CX25840_SVIDEO_CHROMA7) {
				/* ADC2 input select channel 3 */
				cx25840_and_or(client, 0x102, ~0x2, 2);
			} else {
				/* ADC2 input select channel 2 */
				cx25840_and_or(client, 0x102, ~0x2, 0);
			}
		}
	}

	state->vid_input = vid_input;
	state->aud_input = aud_input;
	if (!is_cx2583x(state)) {
		cx25840_audio_set_path(client);
		input_change(client);
	}

	if (is_cx2388x(state)) {
		/* Audio channel 1 src : Parallel 1 */
		cx25840_write(client, 0x124, 0x03);

		/* Select AFE clock pad output source */
		cx25840_write(client, 0x144, 0x05);

		/* I2S_IN_CTL: I2S_IN_SONY_MODE, LEFT SAMPLE on WS=1 */
		cx25840_write(client, 0x914, 0xa0);

		/* I2S_OUT_CTL:
		 * I2S_IN_SONY_MODE, LEFT SAMPLE on WS=1
		 * I2S_OUT_MASTER_MODE = Master
		 */
		cx25840_write(client, 0x918, 0xa0);
		cx25840_write(client, 0x919, 0x01);
	} else if (is_cx231xx(state)) {
		/* Audio channel 1 src : Parallel 1 */
		cx25840_write(client, 0x124, 0x03);

		/* I2S_IN_CTL: I2S_IN_SONY_MODE, LEFT SAMPLE on WS=1 */
		cx25840_write(client, 0x914, 0xa0);

		/* I2S_OUT_CTL:
		 * I2S_IN_SONY_MODE, LEFT SAMPLE on WS=1
		 * I2S_OUT_MASTER_MODE = Master
		 */
		cx25840_write(client, 0x918, 0xa0);
		cx25840_write(client, 0x919, 0x01);
	}

	return 0;
}

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

static int set_v4lstd(struct i2c_client *client)
{
	struct cx25840_state *state = to_state(i2c_get_clientdata(client));
	u8 fmt = 0; 	/* zero is autodetect */
	u8 pal_m = 0;

	/* First tests should be against specific std */
	if (state->std == V4L2_STD_NTSC_M_JP) {
		fmt = 0x2;
	} else if (state->std == V4L2_STD_NTSC_443) {
		fmt = 0x3;
	} else if (state->std == V4L2_STD_PAL_M) {
		pal_m = 1;
		fmt = 0x5;
	} else if (state->std == V4L2_STD_PAL_N) {
		fmt = 0x6;
	} else if (state->std == V4L2_STD_PAL_Nc) {
		fmt = 0x7;
	} else if (state->std == V4L2_STD_PAL_60) {
		fmt = 0x8;
	} else {
		/* Then, test against generic ones */
		if (state->std & V4L2_STD_NTSC)
			fmt = 0x1;
		else if (state->std & V4L2_STD_PAL)
			fmt = 0x4;
		else if (state->std & V4L2_STD_SECAM)
			fmt = 0xc;
	}

	v4l_dbg(1, cx25840_debug, client, "changing video std to fmt %i\n",fmt);

	/* Follow step 9 of section 3.16 in the cx25840 datasheet.
	   Without this PAL may display a vertical ghosting effect.
	   This happens for example with the Yuan MPC622. */
	if (fmt >= 4 && fmt < 8) {
		/* Set format to NTSC-M */
		cx25840_and_or(client, 0x400, ~0xf, 1);
		/* Turn off LCOMB */
		cx25840_and_or(client, 0x47b, ~6, 0);
	}
	cx25840_and_or(client, 0x400, ~0xf, fmt);
	cx25840_and_or(client, 0x403, ~0x3, pal_m);
	cx25840_std_setup(client);
	if (!is_cx2583x(state))
		input_change(client);
	return 0;
}

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

static int cx25840_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
{
	struct cx25840_state *state = to_state(sd);
	struct i2c_client *client = v4l2_get_subdevdata(sd);

	switch (ctrl->id) {
	case CX25840_CID_ENABLE_PVR150_WORKAROUND:
		state->pvr150_workaround = ctrl->value;
		set_input(client, state->vid_input, state->aud_input);
		break;

	case V4L2_CID_BRIGHTNESS:
		if (ctrl->value < 0 || ctrl->value > 255) {
			v4l_err(client, "invalid brightness setting %d\n",
				    ctrl->value);
			return -ERANGE;
		}

		cx25840_write(client, 0x414, ctrl->value - 128);
		break;

	case V4L2_CID_CONTRAST:
		if (ctrl->value < 0 || ctrl->value > 127) {
			v4l_err(client, "invalid contrast setting %d\n",
				    ctrl->value);
			return -ERANGE;
		}

		cx25840_write(client, 0x415, ctrl->value << 1);
		break;

	case V4L2_CID_SATURATION:
		if (ctrl->value < 0 || ctrl->value > 127) {
			v4l_err(client, "invalid saturation setting %d\n",
				    ctrl->value);
			return -ERANGE;
		}

		cx25840_write(client, 0x420, ctrl->value << 1);
		cx25840_write(client, 0x421, ctrl->value << 1);
		break;

	case V4L2_CID_HUE:
		if (ctrl->value < -128 || ctrl->value > 127) {
			v4l_err(client, "invalid hue setting %d\n", ctrl->value);
			return -ERANGE;
		}

		cx25840_write(client, 0x422, ctrl->value);
		break;

	case V4L2_CID_AUDIO_VOLUME:
	case V4L2_CID_AUDIO_BASS:
	case V4L2_CID_AUDIO_TREBLE:
	case V4L2_CID_AUDIO_BALANCE:
	case V4L2_CID_AUDIO_MUTE:
		if (is_cx2583x(state))
			return -EINVAL;
		return cx25840_audio_s_ctrl(sd, ctrl);

	default:
		return -EINVAL;
	}

	return 0;
}

static int cx25840_g_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl)
{
	struct cx25840_state *state = to_state(sd);
	struct i2c_client *client = v4l2_get_subdevdata(sd);

	switch (ctrl->id) {
	case CX25840_CID_ENABLE_PVR150_WORKAROUND:
		ctrl->value = state->pvr150_workaround;
		break;
	case V4L2_CID_BRIGHTNESS:
		ctrl->value = (s8)cx25840_read(client, 0x414) + 128;
		break;
	case V4L2_CID_CONTRAST:
		ctrl->value = cx25840_read(client, 0x415) >> 1;
		break;
	case V4L2_CID_SATURATION:
		ctrl->value = cx25840_read(client, 0x420) >> 1;
		break;
	case V4L2_CID_HUE:
		ctrl->value = (s8)cx25840_read(client, 0x422);
		break;
	case V4L2_CID_AUDIO_VOLUME:
	case V4L2_CID_AUDIO_BASS:
	case V4L2_CID_AUDIO_TREBLE:
	case V4L2_CID_AUDIO_BALANCE:
	case V4L2_CID_AUDIO_MUTE:
		if (is_cx2583x(state))
			return -EINVAL;
		return cx25840_audio_g_ctrl(sd, ctrl);
	default:
		return -EINVAL;
	}

	return 0;
}

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

static int cx25840_g_fmt(struct v4l2_subdev *sd, struct v4l2_format *fmt)
{
	switch (fmt->type) {
	case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
		return cx25840_vbi_g_fmt(sd, fmt);
	default:
		return -EINVAL;
	}
	return 0;
}

static int cx25840_s_fmt(struct v4l2_subdev *sd, struct v4l2_format *fmt)
{
	struct cx25840_state *state = to_state(sd);
	struct i2c_client *client = v4l2_get_subdevdata(sd);
	struct v4l2_pix_format *pix;
	int HSC, VSC, Vsrc, Hsrc, filter, Vlines;
	int is_50Hz = !(state->std & V4L2_STD_525_60);

	switch (fmt->type) {
	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
		pix = &(fmt->fmt.pix);

		Vsrc = (cx25840_read(client, 0x476) & 0x3f) << 4;
		Vsrc |= (cx25840_read(client, 0x475) & 0xf0) >> 4;

		Hsrc = (cx25840_read(client, 0x472) & 0x3f) << 4;
		Hsrc |= (cx25840_read(client, 0x471) & 0xf0) >> 4;

		Vlines = pix->height + (is_50Hz ? 4 : 7);

		if ((pix->width * 16 < Hsrc) || (Hsrc < pix->width) ||
		    (Vlines * 8 < Vsrc) || (Vsrc < Vlines)) {
			v4l_err(client, "%dx%d is not a valid size!\n",
				    pix->width, pix->height);
			return -ERANGE;
		}

		HSC = (Hsrc * (1 << 20)) / pix->width - (1 << 20);
		VSC = (1 << 16) - (Vsrc * (1 << 9) / Vlines - (1 << 9));
		VSC &= 0x1fff;

		if (pix->width >= 385)
			filter = 0;
		else if (pix->width > 192)
			filter = 1;
		else if (pix->width > 96)
			filter = 2;
		else
			filter = 3;

		v4l_dbg(1, cx25840_debug, client, "decoder set size %dx%d -> scale  %ux%u\n",
			    pix->width, pix->height, HSC, VSC);

		/* HSCALE=HSC */
		cx25840_write(client, 0x418, HSC & 0xff);
		cx25840_write(client, 0x419, (HSC >> 8) & 0xff);
		cx25840_write(client, 0x41a, HSC >> 16);
		/* VSCALE=VSC */
		cx25840_write(client, 0x41c, VSC & 0xff);
		cx25840_write(client, 0x41d, VSC >> 8);
		/* VS_INTRLACE=1 VFILT=filter */
		cx25840_write(client, 0x41e, 0x8 | filter);
		break;

	case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
		return cx25840_vbi_s_fmt(sd, fmt);

	case V4L2_BUF_TYPE_VBI_CAPTURE:
		return cx25840_vbi_s_fmt(sd, fmt);

	default:
		return -EINVAL;
	}

	return 0;
}

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

static void log_video_status(struct i2c_client *client)
{
	static const char *const fmt_strs[] = {
		"0x0",
		"NTSC-M", "NTSC-J", "NTSC-4.43",
		"PAL-BDGHI", "PAL-M", "PAL-N", "PAL-Nc", "PAL-60",
		"0x9", "0xA", "0xB",
		"SECAM",
		"0xD", "0xE", "0xF"
	};

	struct cx25840_state *state = to_state(i2c_get_clientdata(client));
	u8 vidfmt_sel = cx25840_read(client, 0x400) & 0xf;
	u8 gen_stat1 = cx25840_read(client, 0x40d);
	u8 gen_stat2 = cx25840_read(client, 0x40e);
	int vid_input = state->vid_input;

	v4l_info(client, "Video signal:              %spresent\n",
		    (gen_stat2 & 0x20) ? "" : "not ");
	v4l_info(client, "Detected format:           %s\n",
		    fmt_strs[gen_stat1 & 0xf]);

	v4l_info(client, "Specified standard:        %s\n",
		    vidfmt_sel ? fmt_strs[vidfmt_sel] : "automatic detection");

	if (vid_input >= CX25840_COMPOSITE1 &&
	    vid_input <= CX25840_COMPOSITE8) {
		v4l_info(client, "Specified video input:     Composite %d\n",
			vid_input - CX25840_COMPOSITE1 + 1);
	} else {
		v4l_info(client, "Specified video input:     S-Video (Luma In%d, Chroma In%d)\n",
			(vid_input & 0xf0) >> 4, (vid_input & 0xf00) >> 8);
	}

	v4l_info(client, "Specified audioclock freq: %d Hz\n", state->audclk_freq);
}

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

static void log_audio_status(struct i2c_client *client)
{
	struct cx25840_state *state = to_state(i2c_get_clientdata(client));
	u8 download_ctl = cx25840_read(client, 0x803);
	u8 mod_det_stat0 = cx25840_read(client, 0x804);
	u8 mod_det_stat1 = cx25840_read(client, 0x805);
	u8 audio_config = cx25840_read(client, 0x808);
	u8 pref_mode = cx25840_read(client, 0x809);
	u8 afc0 = cx25840_read(client, 0x80b);
	u8 mute_ctl = cx25840_read(client, 0x8d3);
	int aud_input = state->aud_input;
	char *p;

	switch (mod_det_stat0) {
	case 0x00: p = "mono"; break;
	case 0x01: p = "stereo"; break;
	case 0x02: p = "dual"; break;
	case 0x04: p = "tri"; break;
	case 0x10: p = "mono with SAP"; break;
	case 0x11: p = "stereo with SAP"; break;
	case 0x12: p = "dual with SAP"; break;
	case 0x14: p = "tri with SAP"; break;
	case 0xfe: p = "forced mode"; break;
	default: p = "not defined";
	}
	v4l_info(client, "Detected audio mode:       %s\n", p);

	switch (mod_det_stat1) {
	case 0x00: p = "not defined"; break;
	case 0x01: p = "EIAJ"; break;
	case 0x02: p = "A2-M"; break;
	case 0x03: p = "A2-BG"; break;
	case 0x04: p = "A2-DK1"; break;
	case 0x05: p = "A2-DK2"; break;
	case 0x06: p = "A2-DK3"; break;
	case 0x07: p = "A1 (6.0 MHz FM Mono)"; break;
	case 0x08: p = "AM-L"; break;
	case 0x09: p = "NICAM-BG"; break;
	case 0x0a: p = "NICAM-DK"; break;
	case 0x0b: p = "NICAM-I"; break;
	case 0x0c: p = "NICAM-L"; break;
	case 0x0d: p = "BTSC/EIAJ/A2-M Mono (4.5 MHz FMMono)"; break;
	case 0x0e: p = "IF FM Radio"; break;
	case 0x0f: p = "BTSC"; break;
	case 0x10: p = "high-deviation FM"; break;
	case 0x11: p = "very high-deviation FM"; break;
	case 0xfd: p = "unknown audio standard"; break;
	case 0xfe: p = "forced audio standard"; break;
	case 0xff: p = "no detected audio standard"; break;
	default: p = "not defined";
	}
	v4l_info(client, "Detected audio standard:   %s\n", p);
	v4l_info(client, "Audio muted:               %s\n",
		    (state->unmute_volume >= 0) ? "yes" : "no");
	v4l_info(client, "Audio microcontroller:     %s\n",
		    (download_ctl & 0x10) ?
				((mute_ctl & 0x2) ? "detecting" : "running") : "stopped");

	switch (audio_config >> 4) {
	case 0x00: p = "undefined"; break;
	case 0x01: p = "BTSC"; break;
	case 0x02: p = "EIAJ"; break;
	case 0x03: p = "A2-M"; break;
	case 0x04: p = "A2-BG"; break;
	case 0x05: p = "A2-DK1"; break;
	case 0x06: p = "A2-DK2"; break;
	case 0x07: p = "A2-DK3"; break;
	case 0x08: p = "A1 (6.0 MHz FM Mono)"; break;
	case 0x09: p = "AM-L"; break;
	case 0x0a: p = "NICAM-BG"; break;
	case 0x0b: p = "NICAM-DK"; break;
	case 0x0c: p = "NICAM-I"; break;
	case 0x0d: p = "NICAM-L"; break;
	case 0x0e: p = "FM radio"; break;
	case 0x0f: p = "automatic detection"; break;
	default: p = "undefined";
	}
	v4l_info(client, "Configured audio standard: %s\n", p);

	if ((audio_config >> 4) < 0xF) {
		switch (audio_config & 0xF) {
		case 0x00: p = "MONO1 (LANGUAGE A/Mono L+R channel for BTSC, EIAJ, A2)"; break;
		case 0x01: p = "MONO2 (LANGUAGE B)"; break;
		case 0x02: p = "MONO3 (STEREO forced MONO)"; break;
		case 0x03: p = "MONO4 (NICAM ANALOG-Language C/Analog Fallback)"; break;
		case 0x04: p = "STEREO"; break;
		case 0x05: p = "DUAL1 (AB)"; break;
		case 0x06: p = "DUAL2 (AC) (FM)"; break;
		case 0x07: p = "DUAL3 (BC) (FM)"; break;
		case 0x08: p = "DUAL4 (AC) (AM)"; break;
		case 0x09: p = "DUAL5 (BC) (AM)"; break;
		case 0x0a: p = "SAP"; break;
		default: p = "undefined";
		}
		v4l_info(client, "Configured audio mode:     %s\n", p);
	} else {
		switch (audio_config & 0xF) {
		case 0x00: p = "BG"; break;
		case 0x01: p = "DK1"; break;
		case 0x02: p = "DK2"; break;
		case 0x03: p = "DK3"; break;
		case 0x04: p = "I"; break;
		case 0x05: p = "L"; break;
		case 0x06: p = "BTSC"; break;
		case 0x07: p = "EIAJ"; break;
		case 0x08: p = "A2-M"; break;
		case 0x09: p = "FM Radio"; break;
		case 0x0f: p = "automatic standard and mode detection"; break;
		default: p = "undefined";
		}
		v4l_info(client, "Configured audio system:   %s\n", p);
	}

	if (aud_input) {
		v4l_info(client, "Specified audio input:     Tuner (In%d)\n", aud_input);
	} else {
		v4l_info(client, "Specified audio input:     External\n");
	}

	switch (pref_mode & 0xf) {
	case 0: p = "mono/language A"; break;
	case 1: p = "language B"; break;
	case 2: p = "language C"; break;
	case 3: p = "analog fallback"; break;
	case 4: p = "stereo"; break;
	case 5: p = "language AC"; break;
	case 6: p = "language BC"; break;
	case 7: p = "language AB"; break;
	default: p = "undefined";
	}
	v4l_info(client, "Preferred audio mode:      %s\n", p);

	if ((audio_config & 0xf) == 0xf) {
		switch ((afc0 >> 3) & 0x3) {
		case 0: p = "system DK"; break;
		case 1: p = "system L"; break;
		case 2: p = "autodetect"; break;
		default: p = "undefined";
		}
		v4l_info(client, "Selected 65 MHz format:    %s\n", p);

		switch (afc0 & 0x7) {
		case 0: p = "chroma"; break;
		case 1: p = "BTSC"; break;
		case 2: p = "EIAJ"; break;
		case 3: p = "A2-M"; break;
		case 4: p = "autodetect"; break;
		default: p = "undefined";
		}
		v4l_info(client, "Selected 45 MHz format:    %s\n", p);
	}
}

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

/* This load_fw operation must be called to load the driver's firmware.
   Without this the audio standard detection will fail and you will
   only get mono.

   Since loading the firmware is often problematic when the driver is
   compiled into the kernel I recommend postponing calling this function
   until the first open of the video device. Another reason for
   postponing it is that loading this firmware takes a long time (seconds)
   due to the slow i2c bus speed. So it will speed up the boot process if
   you can avoid loading the fw as long as the video device isn't used.  */
static int cx25840_load_fw(struct v4l2_subdev *sd)
{
	struct cx25840_state *state = to_state(sd);
	struct i2c_client *client = v4l2_get_subdevdata(sd);

	if (!state->is_initialized) {
		/* initialize and load firmware */
		state->is_initialized = 1;
		if (is_cx2583x(state))
			cx25836_initialize(client);
		else if (is_cx2388x(state))
			cx23885_initialize(client);
		else if (is_cx231xx(state))
			cx231xx_initialize(client);
		else
			cx25840_initialize(client);
	}
	return 0;
}

#ifdef CONFIG_VIDEO_ADV_DEBUG
static int cx25840_g_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
{
	struct i2c_client *client = v4l2_get_subdevdata(sd);

	if (!v4l2_chip_match_i2c_client(client, &reg->match))
		return -EINVAL;
	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;
	reg->size = 1;
	reg->val = cx25840_read(client, reg->reg & 0x0fff);
	return 0;
}

static int cx25840_s_register(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg)
{
	struct i2c_client *client = v4l2_get_subdevdata(sd);

	if (!v4l2_chip_match_i2c_client(client, &reg->match))
		return -EINVAL;
	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;
	cx25840_write(client, reg->reg & 0x0fff, reg->val & 0xff);
	return 0;
}
#endif

static int cx25840_s_stream(struct v4l2_subdev *sd, int enable)
{
	struct cx25840_state *state = to_state(sd);
	struct i2c_client *client = v4l2_get_subdevdata(sd);

	v4l_dbg(1, cx25840_debug, client, "%s output\n",
			enable ? "enable" : "disable");
	if (enable) {
		if (is_cx2388x(state) || is_cx231xx(state)) {
			u8 v = (cx25840_read(client, 0x421) | 0x0b);
			cx25840_write(client, 0x421, v);
		} else {
			cx25840_write(client, 0x115,
					is_cx2583x(state) ? 0x0c : 0x8c);
			cx25840_write(client, 0x116,
					is_cx2583x(state) ? 0x04 : 0x07);
		}
	} else {
		if (is_cx2388x(state) || is_cx231xx(state)) {
			u8 v = cx25840_read(client, 0x421) & ~(0x0b);
			cx25840_write(client, 0x421, v);
		} else {
			cx25840_write(client, 0x115, 0x00);
			cx25840_write(client, 0x116, 0x00);
		}
	}
	return 0;
}

static int cx25840_queryctrl(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc)
{
	struct cx25840_state *state = to_state(sd);

	switch (qc->id) {
	case V4L2_CID_BRIGHTNESS:
		return v4l2_ctrl_query_fill(qc, 0, 255, 1, 128);
	case V4L2_CID_CONTRAST:
	case V4L2_CID_SATURATION:
		return v4l2_ctrl_query_fill(qc, 0, 127, 1, 64);
	case V4L2_CID_HUE:
		return v4l2_ctrl_query_fill(qc, -128, 127, 1, 0);
	default:
		break;
	}
	if (is_cx2583x(state))
		return -EINVAL;

	switch (qc->id) {
	case V4L2_CID_AUDIO_VOLUME:
		return v4l2_ctrl_query_fill(qc, 0, 65535,
				65535 / 100, state->default_volume);
	case V4L2_CID_AUDIO_MUTE:
		return v4l2_ctrl_query_fill(qc, 0, 1, 1, 0);
	case V4L2_CID_AUDIO_BALANCE:
	case V4L2_CID_AUDIO_BASS:
	case V4L2_CID_AUDIO_TREBLE:
		return v4l2_ctrl_query_fill(qc, 0, 65535, 65535 / 100, 32768);
	default:
		return -EINVAL;
	}
	return -EINVAL;
}

static int cx25840_s_std(struct v4l2_subdev *sd, v4l2_std_id std)
{
	struct cx25840_state *state = to_state(sd);
	struct i2c_client *client = v4l2_get_subdevdata(sd);

	if (state->radio == 0 && state->std == std)
		return 0;
	state->radio = 0;
	state->std = std;
	return set_v4lstd(client);
}

static int cx25840_s_radio(struct v4l2_subdev *sd)
{
	struct cx25840_state *state = to_state(sd);

	state->radio = 1;
	return 0;
}

static int cx25840_s_video_routing(struct v4l2_subdev *sd,
				   u32 input, u32 output, u32 config)
{
	struct cx25840_state *state = to_state(sd);
	struct i2c_client *client = v4l2_get_subdevdata(sd);

	return set_input(client, input, state->aud_input);
}

static int cx25840_s_audio_routing(struct v4l2_subdev *sd,
				   u32 input, u32 output, u32 config)
{
	struct cx25840_state *state = to_state(sd);
	struct i2c_client *client = v4l2_get_subdevdata(sd);

	if (is_cx2583x(state))
		return -EINVAL;
	return set_input(client, state->vid_input, input);
}

static int cx25840_s_frequency(struct v4l2_subdev *sd, struct v4l2_frequency *freq)
{
	struct cx25840_state *state = to_state(sd);
	struct i2c_client *client = v4l2_get_subdevdata(sd);

	if (!is_cx2583x(state))
		input_change(client);
	return 0;
}

static int cx25840_g_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *vt)
{
	struct cx25840_state *state = to_state(sd);
	struct i2c_client *client = v4l2_get_subdevdata(sd);
	u8 vpres = cx25840_read(client, 0x40e) & 0x20;
	u8 mode;
	int val = 0;

	if (state->radio)
		return 0;

	vt->signal = vpres ? 0xffff : 0x0;
	if (is_cx2583x(state))
		return 0;

	vt->capability |=
		V4L2_TUNER_CAP_STEREO | V4L2_TUNER_CAP_LANG1 |
		V4L2_TUNER_CAP_LANG2 | V4L2_TUNER_CAP_SAP;

	mode = cx25840_read(client, 0x804);

	/* get rxsubchans and audmode */
	if ((mode & 0xf) == 1)
		val |= V4L2_TUNER_SUB_STEREO;
	else
		val |= V4L2_TUNER_SUB_MONO;

	if (mode == 2 || mode == 4)
		val = V4L2_TUNER_SUB_LANG1 | V4L2_TUNER_SUB_LANG2;

	if (mode & 0x10)
		val |= V4L2_TUNER_SUB_SAP;

	vt->rxsubchans = val;
	vt->audmode = state->audmode;
	return 0;
}

static int cx25840_s_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *vt)
{
	struct cx25840_state *state = to_state(sd);
	struct i2c_client *client = v4l2_get_subdevdata(sd);

	if (state->radio || is_cx2583x(state))
		return 0;

	switch (vt->audmode) {
		case V4L2_TUNER_MODE_MONO:
			/* mono      -> mono
			   stereo    -> mono
			   bilingual -> lang1 */
			cx25840_and_or(client, 0x809, ~0xf, 0x00);
			break;
		case V4L2_TUNER_MODE_STEREO:
		case V4L2_TUNER_MODE_LANG1:
			/* mono      -> mono
			   stereo    -> stereo
			   bilingual -> lang1 */
			cx25840_and_or(client, 0x809, ~0xf, 0x04);
			break;
		case V4L2_TUNER_MODE_LANG1_LANG2:
			/* mono      -> mono
			   stereo    -> stereo
			   bilingual -> lang1/lang2 */
			cx25840_and_or(client, 0x809, ~0xf, 0x07);
			break;
		case V4L2_TUNER_MODE_LANG2:
			/* mono      -> mono
			   stereo    -> stereo
			   bilingual -> lang2 */
			cx25840_and_or(client, 0x809, ~0xf, 0x01);
			break;
		default:
			return -EINVAL;
	}
	state->audmode = vt->audmode;
	return 0;
}

static int cx25840_reset(struct v4l2_subdev *sd, u32 val)
{
	struct cx25840_state *state = to_state(sd);
	struct i2c_client *client = v4l2_get_subdevdata(sd);

	if (is_cx2583x(state))
		cx25836_initialize(client);
	else if (is_cx2388x(state))
		cx23885_initialize(client);
	else if (is_cx231xx(state))
		cx231xx_initialize(client);
	else
		cx25840_initialize(client);
	return 0;
}

static int cx25840_g_chip_ident(struct v4l2_subdev *sd, struct v4l2_dbg_chip_ident *chip)
{
	struct cx25840_state *state = to_state(sd);
	struct i2c_client *client = v4l2_get_subdevdata(sd);

	return v4l2_chip_ident_i2c_client(client, chip, state->id, state->rev);
}

static int cx25840_log_status(struct v4l2_subdev *sd)
{
	struct cx25840_state *state = to_state(sd);
	struct i2c_client *client = v4l2_get_subdevdata(sd);

	log_video_status(client);
	if (!is_cx2583x(state))
		log_audio_status(client);
	return 0;
}

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

static const struct v4l2_subdev_core_ops cx25840_core_ops = {
	.log_status = cx25840_log_status,
	.g_chip_ident = cx25840_g_chip_ident,
	.g_ctrl = cx25840_g_ctrl,
	.s_ctrl = cx25840_s_ctrl,
	.queryctrl = cx25840_queryctrl,
	.s_std = cx25840_s_std,
	.reset = cx25840_reset,
	.load_fw = cx25840_load_fw,
#ifdef CONFIG_VIDEO_ADV_DEBUG
	.g_register = cx25840_g_register,
	.s_register = cx25840_s_register,
#endif
};

static const struct v4l2_subdev_tuner_ops cx25840_tuner_ops = {
	.s_frequency = cx25840_s_frequency,
	.s_radio = cx25840_s_radio,
	.g_tuner = cx25840_g_tuner,
	.s_tuner = cx25840_s_tuner,
};

static const struct v4l2_subdev_audio_ops cx25840_audio_ops = {
	.s_clock_freq = cx25840_s_clock_freq,
	.s_routing = cx25840_s_audio_routing,
};

static const struct v4l2_subdev_video_ops cx25840_video_ops = {
	.s_routing = cx25840_s_video_routing,
	.g_fmt = cx25840_g_fmt,
	.s_fmt = cx25840_s_fmt,
	.decode_vbi_line = cx25840_decode_vbi_line,
	.s_stream = cx25840_s_stream,
};

static const struct v4l2_subdev_ops cx25840_ops = {
	.core = &cx25840_core_ops,
	.tuner = &cx25840_tuner_ops,
	.audio = &cx25840_audio_ops,
	.video = &cx25840_video_ops,
};

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

static u32 get_cx2388x_ident(struct i2c_client *client)
{
	u32 ret;

	/* Come out of digital power down */
	cx25840_write(client, 0x000, 0);

	/* Detecting whether the part is cx23885/7/8 is more
	 * difficult than it needs to be. No ID register. Instead we
	 * probe certain registers indicated in the datasheets to look
	 * for specific defaults that differ between the silicon designs. */

	/* It's either 885/7 if the IR Tx Clk Divider register exists */
	if (cx25840_read4(client, 0x204) & 0xffff) {
		/* CX23885 returns bogus repetitive byte values for the DIF,
		 * which doesn't exist for it. (Ex. 8a8a8a8a or 31313131) */
		ret = cx25840_read4(client, 0x300);
		if (((ret & 0xffff0000) >> 16) == (ret & 0xffff)) {
			/* No DIF */
			ret = V4L2_IDENT_CX23885_AV;
		} else {
			/* CX23887 has a broken DIF, but the registers
			 * appear valid (but unsed), good enough to detect. */
			ret = V4L2_IDENT_CX23887_AV;
		}
	} else if (cx25840_read4(client, 0x300) & 0x0fffffff) {
		/* DIF PLL Freq Word reg exists; chip must be a CX23888 */
		ret = V4L2_IDENT_CX23888_AV;
	} else {
		v4l_err(client, "Unable to detect h/w, assuming cx23887\n");
		ret = V4L2_IDENT_CX23887_AV;
	}

	/* Back into digital power down */
	cx25840_write(client, 0x000, 2);
	return ret;
}

static int cx25840_probe(struct i2c_client *client,
			 const struct i2c_device_id *did)
{
	struct cx25840_state *state;
	struct v4l2_subdev *sd;
	u32 id = V4L2_IDENT_NONE;
	u16 device_id;

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

	v4l_dbg(1, cx25840_debug, client, "detecting cx25840 client on address 0x%x\n", client->addr << 1);

	device_id = cx25840_read(client, 0x101) << 8;
	device_id |= cx25840_read(client, 0x100);
	v4l_dbg(1, cx25840_debug, client, "device_id = 0x%04x\n", device_id);

	/* The high byte of the device ID should be
	 * 0x83 for the cx2583x and 0x84 for the cx2584x */
	if ((device_id & 0xff00) == 0x8300) {
		id = V4L2_IDENT_CX25836 + ((device_id >> 4) & 0xf) - 6;
	} else if ((device_id & 0xff00) == 0x8400) {
		id = V4L2_IDENT_CX25840 + ((device_id >> 4) & 0xf);
	} else if (device_id == 0x0000) {
		id = get_cx2388x_ident(client);
	} else if ((device_id & 0xfff0) == 0x5A30) {
		/* The CX23100 (0x5A3C = 23100) doesn't have an A/V decoder */
		id = V4L2_IDENT_CX2310X_AV;
	} else if ((device_id & 0xff) == (device_id >> 8)) {
		v4l_err(client,
			"likely a confused/unresponsive cx2388[578] A/V decoder"
			" found @ 0x%x (%s)\n",
			client->addr << 1, client->adapter->name);
		v4l_err(client, "A method to reset it from the cx25840 driver"
			" software is not known at this time\n");
		return -ENODEV;
	} else {
		v4l_dbg(1, cx25840_debug, client, "cx25840 not found\n");
		return -ENODEV;
	}

	state = kzalloc(sizeof(struct cx25840_state), GFP_KERNEL);
	if (state == NULL)
		return -ENOMEM;

	sd = &state->sd;
	v4l2_i2c_subdev_init(sd, client, &cx25840_ops);
	switch (id) {
	case V4L2_IDENT_CX23885_AV:
		v4l_info(client, "cx23885 A/V decoder found @ 0x%x (%s)\n",
			 client->addr << 1, client->adapter->name);
		break;
	case V4L2_IDENT_CX23887_AV:
		v4l_info(client, "cx23887 A/V decoder found @ 0x%x (%s)\n",
			 client->addr << 1, client->adapter->name);
		break;
	case V4L2_IDENT_CX23888_AV:
		v4l_info(client, "cx23888 A/V decoder found @ 0x%x (%s)\n",
			 client->addr << 1, client->adapter->name);
		break;
	case V4L2_IDENT_CX2310X_AV:
		v4l_info(client, "cx%d A/V decoder found @ 0x%x (%s)\n",
			 device_id, client->addr << 1, client->adapter->name);
		break;
	case V4L2_IDENT_CX25840:
	case V4L2_IDENT_CX25841:
	case V4L2_IDENT_CX25842:
	case V4L2_IDENT_CX25843:
		/* Note: revision '(device_id & 0x0f) == 2' was never built. The
		   marking skips from 0x1 == 22 to 0x3 == 23. */
		v4l_info(client, "cx25%3x-2%x found @ 0x%x (%s)\n",
			 (device_id & 0xfff0) >> 4,
			 (device_id & 0x0f) < 3 ? (device_id & 0x0f) + 1
						: (device_id & 0x0f),
			 client->addr << 1, client->adapter->name);
		break;
	case V4L2_IDENT_CX25836:
	case V4L2_IDENT_CX25837:
	default:
		v4l_info(client, "cx25%3x-%x found @ 0x%x (%s)\n",
			 (device_id & 0xfff0) >> 4, device_id & 0x0f,
			 client->addr << 1, client->adapter->name);
		break;
	}

	state->c = client;
	state->vid_input = CX25840_COMPOSITE7;
	state->aud_input = CX25840_AUDIO8;
	state->audclk_freq = 48000;
	state->pvr150_workaround = 0;
	state->audmode = V4L2_TUNER_MODE_LANG1;
	state->unmute_volume = -1;
	state->default_volume = 228 - cx25840_read(client, 0x8d4);
	state->default_volume = ((state->default_volume / 2) + 23) << 9;
	state->vbi_line_offset = 8;
	state->id = id;
	state->rev = device_id;

	return 0;
}

static int cx25840_remove(struct i2c_client *client)
{
	struct v4l2_subdev *sd = i2c_get_clientdata(client);

	v4l2_device_unregister_subdev(sd);
	kfree(to_state(sd));
	return 0;
}

static const struct i2c_device_id cx25840_id[] = {
	{ "cx25840", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, cx25840_id);

static struct v4l2_i2c_driver_data v4l2_i2c_data = {
	.name = "cx25840",
	.probe = cx25840_probe,
	.remove = cx25840_remove,
	.id_table = cx25840_id,
};