path: root/drivers/media/dvb/frontends/lgs8gxx.c

/*
 *    Support for Legend Silicon GB20600 (a.k.a DMB-TH) demodulator
 *    LGS8913, LGS8GL5, LGS8G75
 *    experimental support LGS8G42, LGS8G52
 *
 *    Copyright (C) 2007-2009 David T.L. Wong <davidtlwong@gmail.com>
 *    Copyright (C) 2008 Sirius International (Hong Kong) Limited
 *    Timothy Lee <timothy.lee@siriushk.com> (for initial work on LGS8GL5)
 *
 *    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 <asm/div64.h>
#include <linux/firmware.h>

#include "dvb_frontend.h"

#include "lgs8gxx.h"
#include "lgs8gxx_priv.h"

#define dprintk(args...) \
	do { \
		if (debug) \
			printk(KERN_DEBUG "lgs8gxx: " args); \
	} while (0)

static int debug;
static int fake_signal_str = 1;

module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");

module_param(fake_signal_str, int, 0644);
MODULE_PARM_DESC(fake_signal_str, "fake signal strength for LGS8913."
"Signal strength calculation is slow.(default:on).");

/* LGS8GXX internal helper functions */

static int lgs8gxx_write_reg(struct lgs8gxx_state *priv, u8 reg, u8 data)
{
	int ret;
	u8 buf[] = { reg, data };
	struct i2c_msg msg = { .flags = 0, .buf = buf, .len = 2 };

	msg.addr = priv->config->demod_address;
	if (priv->config->prod != LGS8GXX_PROD_LGS8G75 && reg >= 0xC0)
		msg.addr += 0x02;

	if (debug >= 2)
		dprintk("%s: reg=0x%02X, data=0x%02X\n", __func__, reg, data);

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

	if (ret != 1)
		dprintk("%s: error reg=0x%x, data=0x%x, ret=%i\n",
			__func__, reg, data, ret);

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

static int lgs8gxx_read_reg(struct lgs8gxx_state *priv, u8 reg, u8 *p_data)
{
	int ret;
	u8 dev_addr;

	u8 b0[] = { reg };
	u8 b1[] = { 0 };
	struct i2c_msg msg[] = {
		{ .flags = 0, .buf = b0, .len = 1 },
		{ .flags = I2C_M_RD, .buf = b1, .len = 1 },
	};

	dev_addr = priv->config->demod_address;
	if (priv->config->prod != LGS8GXX_PROD_LGS8G75 && reg >= 0xC0)
		dev_addr += 0x02;
	msg[1].addr =  msg[0].addr = dev_addr;

	ret = i2c_transfer(priv->i2c, msg, 2);
	if (ret != 2) {
		dprintk("%s: error reg=0x%x, ret=%i\n", __func__, reg, ret);
		return -1;
	}

	*p_data = b1[0];
	if (debug >= 2)
		dprintk("%s: reg=0x%02X, data=0x%02X\n", __func__, reg, b1[0]);
	return 0;
}

static int lgs8gxx_soft_reset(struct lgs8gxx_state *priv)
{
	lgs8gxx_write_reg(priv, 0x02, 0x00);
	msleep(1);
	lgs8gxx_write_reg(priv, 0x02, 0x01);
	msleep(100);

	return 0;
}

static int wait_reg_mask(struct lgs8gxx_state *priv, u8 reg, u8 mask,
	u8 val, u8 delay, u8 tries)
{
	u8 t;
	int i;

	for (i = 0; i < tries; i++) {
		lgs8gxx_read_reg(priv, reg, &t);

		if ((t & mask) == val)
			return