path: root/drivers/media/dvb/frontends/au8522.c

/*
    Auvitek AU8522 QAM/8VSB demodulator driver

    Copyright (C) 2008 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., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include "dvb_frontend.h"
#include "au8522.h"

struct au8522_state {

	struct i2c_adapter *i2c;

	/* configuration settings */
	const struct au8522_config *config;

	struct dvb_frontend frontend;

	u32 current_frequency;
	fe_modulation_t current_modulation;

};

static int debug;

#define dprintk(arg...) do {		\
	if (debug) 			\
		 printk(arg); 		\
	} while (0)

/* 16 bit registers, 8 bit values */
static int au8522_writereg(struct au8522_state *state, u16 reg, u8 data)
{
	int ret;
	u8 buf [] = { reg >> 8, reg & 0xff, data };

	struct i2c_msg msg = { .addr = state->config->demod_address,
			       .flags = 0, .buf = buf, .len = 3 };

	ret = i2c_transfer(state->i2c, &msg, 1);

	if (ret != 1)
		printk("%s: writereg error (reg == 0x%02x, val == 0x%04x, "
		       "ret == %i)\n", __func__, reg, data, ret);

	return (ret != 1) ? -1 : 0;
}

static u8 au8522_readreg(struct au8522_state *state, u16 reg)
{
	int ret;
	u8 b0 [] = { reg >> 8, reg & 0xff };
	u8 b1 [] = { 0 };

	struct i2c_msg msg [] = {
		{ .addr = state->config->demod_address, .flags = 0,
		  .buf = b0, .len = 2 },
		{ .addr = state->config->demod_address, .flags = I2C_M_RD,
		  .buf = b1, .len = 1 } };

	ret = i2c_transfer(state->i2c, msg, 2);

	if (ret != 2)
		printk(KERN_ERR "%s: readreg error (ret == %i)\n",
		       __func__, ret);
	return b1[0];
}

static int au8522_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
{
	struct au8522_state *state = fe->demodulator_priv;

	dprintk("%s(%d)\n", __func__, enable);

	if (enable)
		return au8522_writereg(state, 0x106, 1);
	else
		return au8522_writereg(state, 0x106, 0);
}

struct mse2snr_tab {
	u16 val;
	u16 data;
};

/* VSB SNR lookup table */
static struct mse2snr_tab vsb_mse2snr_tab[] = {
	{   0, 270 },
	{   2, 250 },
	{   3, 240 },
	{   5, 230 },
	{   7, 220 },
	{   9, 210 },
	{  12, 200 },
	{  13, 195 },
	{  15, 190 },
	{  17, 185 },
	{  19, 180 },
	{  21, 175 },
	{  24, 170 },
	{  27, 165 },
	{  31, 160 },
	{  32, 158 },
	{  33, 156 },
	{  36, 152 },
	{  37, 150 },
	{  39, 148 },
	{  40, 146 },
	{  41, 144 },
	{  43, 142 },
	{  44, 140 },
	{  48, 135 },
	{  50, 130 },
	{  43, 142 },
	{  53, 125 },
	{  56, 120 },
	{ 256, 115 },
};

/* QAM64 SNR lookup table */
static struct mse2snr_tab qam64_mse2snr_tab[] = {
	{  15,   0 },
	{  16, 290 },
	{  17, 288 },
	{  18, 286 },
	{  19, 284 },
	{  20, 282 },
	{  21, 281 },
	{  22, 279 },
	{  23, 277 },
	{  24, 275 },
	{  25, 273 },
	{  26, 271 },
	{  27, 269 },
	{  28, 268 },
	{  29, 266 },
	{  30, 264 },
	{  31, 262 },
	{  32, 260 },
	{  33, 259 },
	{  34, 258 },
	{  35, 256 },
	{  36, 255 },
	{  37, 254 },
	{  38, 252 },
	{  39, 251 },
	{  40, 250 },
	{  41, 249 },
	{  42, 248 },
	{  43, 246 },
	{  44, 245 },
	{  45, 244 },
	{  46, 242 },
	{  47, 241 },
	{  48, 240 },
	{  50, 239 },
	{  51, 238 },
	{  53, 237 </