V4L/DVB (11398): Support for Legend Silicon LGS8913/LGS8GL5/LGS8GXX China DMB-TH digital demodulator

This patch contains the unified driver for Legend Silicon LGS8913 and
LGS8GL5. It should replace lgs8gl5.c in media/dvb/frontends in the future.

Signed-off-by: David T.L. Wong <davidtlwong@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 816 insertions, 0 deletions

diff --git a/drivers/media/dvb/frontends/lgs8gxx.c b/drivers/media/dvb/frontends/lgs8gxx.c
new file mode 100644
index 00000000000..f9785dfe735
--- /dev/null
+++ b/drivers/media/dvb/frontends/lgs8gxx.c
@@ -0,0 +1,816 @@
+/*
+ *    Support for Legend Silicon DMB-TH demodulator
+ *    LGS8913, LGS8GL5
+ *    experimental support LGS8G42, LGS8G52
+ *
+ *    Copyright (C) 2007,2008 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 "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;
+
+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:off).");
+
+/* 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 (reg >= 0xC0)
+		msg.addr += 0x02;
+
+	if (debug >= 2)
+		printk(KERN_DEBUG "%s: reg=0x%02X, data=0x%02X\n",
+			__func__, reg, data);
+
+	ret = i2c_transfer(priv->i2c, &msg, 1);
+
+	if (ret != 1)
+		dprintk(KERN_DEBUG "%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 (reg >= 0xC0)
+		dev_addr += 0x02;
+	msg[1].addr =  msg[0].addr = dev_addr;
+
+	ret = i2c_transfer(priv->i2c, msg, 2);
+	if (ret != 2) {
+		dprintk(KERN_DEBUG "%s: error reg=0x%x, ret=%i\n",
+			__func__, reg, ret);
+		return -1;
+	}
+
+	*p_data = b1[0];
+	if (debug >= 2)
+		printk(KERN_DEBUG "%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 lgs8gxx_set_ad_mode(struct lgs8gxx_state *priv)
+{
+	const struct lgs8gxx_config *config = priv->config;
+	u8 if_conf;
+
+	if_conf = 0x10; /* AGC output on; */
+
+	if_conf |=
+		((config->ext_adc) ? 0x80 : 0x00) |
+		((config->if_neg_center) ? 0x04 : 0x00) |
+		((config->if_freq == 0) ? 0x08 : 0x00) | /* Baseband */
+		((config->ext_adc && config->adc_signed) ? 0x02 : 0x00) |
+		((config->ext_adc && config->if_neg_edge) ? 0x01 : 0x00);
+
+	if (config->ext_adc &&
+		(config->prod == LGS8GXX_PROD_LGS8G52)) {
+		lgs8gxx_write_reg(priv, 0xBA, 0x40);
+	}
+
+	lgs8gxx_write_reg(priv, 0x07, if_conf);
+
+	return 0;
+}
+
+static int lgs8gxx_set_if_freq(struct lgs8gxx_state *priv, u32 freq /*in kHz*/)
+{
+	u64 val;
+	u32 v32;
+	u32 if_clk;
+
+	if_clk = priv->config->if_clk_freq;
+
+	val = freq;
+	if (freq != 0) {
+		val *= (u64)1 << 32;
+		if (if_clk != 0)
+			do_div(val, if_clk);
+		v32 = val & 0xFFFFFFFF;
+		dprintk("Set IF Freq to %dkHz\n", freq);
+	} else {
+		v32 = 0;
+		dprintk("Set IF Freq to baseband\n");
+	}
+	dprintk("AFC_INIT_FREQ = 0x%08X\n", v32);
+
+	lgs8gxx_write_reg(priv, 0x09, 0xFF & (v32));
+	lgs8gxx_write_reg(priv, 0x0A, 0xFF & (v32 >> 8));
+	lgs8gxx_write_reg(priv, 0x0B, 0xFF & (v32 >> 16));
+	lgs8gxx_write_reg(priv, 0x0C, 0xFF & (v32 >> 24));
+
+	return 0;
+}
+
+static int lgs8gxx_set_mode_auto(struct lgs8gxx_state *priv)
+{
+	u8 t;
+
+	if (priv->config->prod == LGS8GXX_PROD_LGS8913)
+		lgs8gxx_write_reg(priv, 0xC6, 0x01);
+
+	lgs8gxx_read_reg(priv, 0x7E, &t);
+	lgs8gxx_write_reg(priv, 0x7E, t | 0x01);
+
+	/* clear FEC self reset */
+	lgs8gxx_read_reg(priv, 0xC5, &t);
+	lgs8gxx_write_reg(priv, 0xC5, t & 0xE0);
+
+	if (priv->config->prod == LGS8GXX_PROD_LGS8913) {
+		/* FEC auto detect */
+		lgs8gxx_write_reg(priv, 0xC1, 0x03);
+
+		lgs8gxx_read_reg(priv, 0x7C, &t);
+		t = (t & 0x8C) | 0x03;
+		lgs8gxx_write_reg(priv, 0x7C, t);
+	}
+
+
+	if (priv->config->prod == LGS8GXX_PROD_LGS8913) {
+		/* BER test mode */
+		lgs8gxx_read_reg(priv, 0xC3, &t);
+		t = (t & 0xEF) |  0x10;
+		lgs8gxx_write_reg(priv, 0xC3, t);
+	}
+
+	if (priv->config->prod == LGS8GXX_PROD_LGS8G52)
+		lgs8gxx_write_reg(priv, 0xD9, 0x40);
+
+	return 0;
+}
+
+static int lgs8gxx_set_mode_manual(struct lgs8gxx_state *priv)
+{
+	int ret = 0;
+	u8 t;
+
+	/* turn off auto-detect; manual settings */
+	lgs8gxx_write_reg(priv, 0x7E, 0);
+	if (priv->config->prod == LGS8GXX_PROD_LGS8913)
+		lgs8gxx_write_reg(priv, 0xC1, 0);
+
+	ret = lgs8gxx_read_reg(priv, 0xC5, &t);
+	t = (t & 0xE0) | 0x06;
+	lgs8gxx_write_reg(priv, 0xC5, t);
+
+	lgs8gxx_soft_reset(priv);
+
+	return 0;
+}
+
+static int lgs8gxx_is_locked(struct lgs8gxx_state *priv, u8 *locked)
+{
+	int ret = 0;
+	u8 t;
+
+	ret = lgs8gxx_read_reg(priv, 0x4B, &t);
+	if (ret != 0)
+		return ret;
+
+	*locked = ((t & 0xC0) == 0xC0) ? 1 : 0;
+	return 0;
+}
+
+static int lgs8gxx_is_autodetect_finished(struct lgs8gxx_state *priv,
+					  u8 *finished)
+{
+	int ret = 0;
+	u8 t;
+
+	ret = lgs8gxx_read_reg(priv, 0xA4, &t);
+	if (ret != 0)
+		return ret;
+
+	*finished = ((t & 0x3) == 0x1) ? 1 : 0;
+
+	return 0;
+}
+
+static int lgs8gxx_autolock_gi(struct lgs8gxx_state *priv, u8 gi, u8 *locked)
+{
+	int err;
+	u8 ad_fini = 0;
+
+	if (gi == GI_945)
+		dprintk("try GI 945\n");
+	else if (gi == GI_595)
+		dprintk("try GI 595\n");
+	else if (gi == GI_420)
+		dprintk("try GI 420\n");
+	lgs8gxx_write_reg(priv, 0x04, gi);
+	lgs8gxx_soft_reset(priv);
+	msleep(50);
+	err = lgs8gxx_is_autodetect_finished(priv, &ad_fini);
+	if (err != 0)
+		return err;
+	if (ad_fini) {
+		err = lgs8gxx_is_locked(priv, locked);
+		if (err != 0)
+			return err;
+	}
+
+	return 0;
+}
+
+static int lgs8gxx_auto_detect(struct lgs8gxx_state *priv,
+			       u8 *detected_param, u8 *gi)
+{
+	int i, j;
+	int err = 0;
+	u8 locked = 0, tmp_gi;
+
+	dprintk("%s\n", __func__);
+
+	lgs8gxx_set_mode_auto(priv);
+	/* Guard Interval */
+	lgs8gxx_write_reg(priv, 0x03, 00);
+
+	for (i = 0; i < 2; i++) {
+		for (j = 0; j < 2; j++) {
+			tmp_gi = GI_945;
+			err = lgs8gxx_autolock_gi(priv, GI_945, &locked);
+			if (err)
+				goto out;
+			if (locked)
+				goto locked;
+		}
+		for (j = 0; j < 2; j++) {
+			tmp_gi = GI_420;
+			err = lgs8gxx_autolock_gi(priv, GI_420, &locked);
+			if (err)
+				goto out;
+			if (locked)
+				goto locked;
+		}
+		tmp_gi = GI_595;
+		err = lgs8gxx_autolock_gi(priv, GI_595, &locked);
+		if (err)
+			goto out;
+		if (locked)
+			goto locked;
+	}
+
+locked:
+	if ((err == 0) && (locked == 1)) {
+		u8 t;
+
+		lgs8gxx_read_reg(priv, 0xA2, &t);
+		*detected_param = t;
+
+		if (tmp_gi == GI_945)
+			dprintk("GI 945 locked\n");
+		else if (tmp_gi == GI_595)
+			dprintk("GI 595 locked\n");
+		else if (tmp_gi == GI_420)
+			dprintk("GI 420 locked\n");
+		*gi = tmp_gi;
+	}
+	if (!locked)
+		err = -1;
+
+out:
+	return err;
+}
+
+static void lgs8gxx_auto_lock(struct lgs8gxx_state *priv)
+{
+	s8 err;
+	u8 gi = 0x2;
+	u8 detected_param = 0;
+
+	err = lgs8gxx_auto_detect(priv, &detected_param, &gi);
+
+	if (err != 0) {
+		dprintk("lgs8gxx_auto_detect failed\n");
+	}
+
+	/* Apply detected parameters */
+	if (priv->config->prod == LGS8GXX_PROD_LGS8913) {
+		u8 inter_leave_len = detected_param & TIM_MASK ;
+		inter_leave_len = (inter_leave_len == TIM_LONG) ? 0x60 : 0x40;
+		detected_param &= CF_MASK | SC_MASK  | LGS_FEC_MASK;
+		detected_param |= inter_leave_len;
+	}
+	lgs8gxx_write_reg(priv, 0x7D, detected_param);
+	if (priv->config->prod == LGS8GXX_PROD_LGS8913)
+		lgs8gxx_write_reg(priv, 0xC0, detected_param);
+	/* lgs8gxx_soft_reset(priv); */
+
+	/* Enter manual mode */
+	lgs8gxx_set_mode_manual(priv);
+
+	switch (gi) {
+	case GI_945:
+		priv->curr_gi = 945; break;
+	case GI_595:
+		priv->curr_gi = 595; break;
+	case GI_420:
+		priv->curr_gi = 420; break;
+	default:
+		priv->curr_gi = 945; break;
+	}
+}
+
+static int lgs8gxx_set_mpeg_mode(struct lgs8gxx_state *priv,
+	u8 serial, u8 clk_pol, u8 clk_gated)
+{
+	int ret = 0;
+	u8 t;
+
+	ret = lgs8gxx_read_reg(priv, 0xC2, &t);
+	if (ret != 0)
+		return ret;
+
+	t &= 0xF8;
+	t |= serial ? TS_SERIAL : TS_PARALLEL;
+	t |= clk_pol ? TS_CLK_INVERTED : TS_CLK_NORMAL;
+	t |= clk_gated ? TS_CLK_GATED : TS_CLK_FREERUN;
+
+	ret = lgs8gxx_write_reg(priv, 0xC2, t);
+	if (ret != 0)
+		return ret;
+
+	return 0;
+}
+
+
+/* LGS8913 demod frontend functions */
+
+static int lgs8913_init(struct lgs8gxx_state *priv)
+{
+	u8 t;
+
+	/* LGS8913 specific */
+	lgs8gxx_write_reg(priv, 0xc1, 0x3);
+
+	lgs8gxx_read_reg(priv, 0x7c, &t);
+	lgs8gxx_write_reg(priv, 0x7c, (t&0x8c) | 0x3);
+
+	/* LGS8913 specific */
+	lgs8gxx_read_reg(priv, 0xc3, &t);
+	lgs8gxx_write_reg(priv, 0xc3, t&0x10);
+
+
+	return 0;
+}
+
+static int lgs8gxx_init(struct dvb_frontend *fe)
+{
+	struct lgs8gxx_state *priv =
+		(struct lgs8gxx_state *)fe->demodulator_priv;
+	const struct lgs8gxx_config *config = priv->config;
+	u8 data = 0;
+	s8 err;
+	dprintk("%s\n", __func__);
+
+	lgs8gxx_read_reg(priv, 0, &data);
+	dprintk("reg 0 = 0x%02X\n", data);
+
+	/* Setup MPEG output format */
+	err = lgs8gxx_set_mpeg_mode(priv, config->serial_ts,
+				    config->ts_clk_pol,
+				    config->ts_clk_gated);
+	if (err != 0)
+		return -EIO;
+
+	if (config->prod == LGS8GXX_PROD_LGS8913)
+		lgs8913_init(priv);
+	lgs8gxx_set_if_freq(priv, priv->config->if_freq);
+	if (config->prod != LGS8GXX_PROD_LGS8913)
+		lgs8gxx_set_ad_mode(priv);
+
+	return 0;
+}
+
+static void lgs8gxx_release(struct dvb_frontend *fe)
+{
+	struct lgs8gxx_state *state = fe->demodulator_priv;
+	dprintk("%s\n", __func__);
+
+	kfree(state);
+}
+
+
+static int lgs8gxx_write(struct dvb_frontend *fe, u8 *buf, int len)
+{
+	struct lgs8gxx_state *priv = fe->demodulator_priv;
+
+	if (len != 2)
+		return -EINVAL;
+
+	return lgs8gxx_write_reg(priv, buf[0], buf[1]);
+}
+
+static int lgs8gxx_set_fe(struct dvb_frontend *fe,
+			  struct dvb_frontend_parameters *fe_params)
+{
+	struct lgs8gxx_state *priv = fe->demodulator_priv;
+
+	dprintk("%s\n", __func__);
+
+	/* set frequency */
+	if (fe->ops.tuner_ops.set_params) {
+		fe->ops.tuner_ops.set_params(fe, fe_params);
+		if (fe->ops.i2c_gate_ctrl)
+			fe->ops.i2c_gate_ctrl(fe, 0);
+	}
+
+	/* start auto lock */
+	lgs8gxx_auto_lock(priv);
+
+	msleep(10);
+
+	return 0;
+}
+
+static int lgs8gxx_get_fe(struct dvb_frontend *fe,
+			  struct dvb_frontend_parameters *fe_params)
+{
+	struct lgs8gxx_state *priv = fe->demodulator_priv;
+	u8 t;
+
+	dprintk("%s\n", __func__);
+
+	/* TODO: get real readings from device */
+	/* inversion status */
+	fe_params->inversion = INVERSION_OFF;
+
+	/* bandwidth */
+	fe_params->u.ofdm.bandwidth = BANDWIDTH_8_MHZ;
+
+
+	lgs8gxx_read_reg(priv, 0x7D, &t);
+	fe_params->u.ofdm.code_rate_HP = FEC_AUTO;
+	fe_params->u.ofdm.code_rate_LP = FEC_AUTO;
+
+	/* constellation */
+	switch (t & SC_MASK) {
+	case SC_QAM64:
+		fe_params->u.ofdm.constellation = QAM_64;
+		break;
+	case SC_QAM32:
+		fe_params->u.ofdm.constellation = QAM_32;
+		break;
+	case SC_QAM16:
+		fe_params->u.ofdm.constellation = QAM_16;
+		break;
+	case SC_QAM4:
+	case SC_QAM4NR:
+		fe_params->u.ofdm.constellation = QPSK;
+		break;
+	default:
+		fe_params->u.ofdm.constellation = QAM_64;
+	}
+
+	/* transmission mode */
+	fe_params->u.ofdm.transmission_mode = TRANSMISSION_MODE_AUTO;
+
+	/* guard interval */
+	fe_params->u.ofdm.guard_interval = GUARD_INTERVAL_AUTO;
+
+	/* hierarchy */
+	fe_params->u.ofdm.hierarchy_information = HIERARCHY_NONE;
+
+	return 0;
+}
+
+static
+int lgs8gxx_get_tune_settings(struct dvb_frontend *fe,
+			      struct dvb_frontend_tune_settings *fesettings)
+{
+	/* FIXME: copy from tda1004x.c */
+	fesettings->min_delay_ms = 800;
+	fesettings->step_size = 0;
+	fesettings->max_drift = 0;
+	return 0;
+}
+
+static int lgs8gxx_read_status(struct dvb_frontend *fe, fe_status_t *fe_status)
+{
+	struct lgs8gxx_state *priv = fe->demodulator_priv;
+	s8 ret;
+	u8 t;
+
+	dprintk("%s\n", __func__);
+
+	ret = lgs8gxx_read_reg(priv, 0x4B, &t);
+	if (ret != 0)
+		return -EIO;
+
+	dprintk("Reg 0x4B: 0x%02X\n", t);
+
+	*fe_status = 0;
+	if (priv->config->prod == LGS8GXX_PROD_LGS8913) {
+		if ((t & 0x40) == 0x40)
+			*fe_status |= FE_HAS_SIGNAL | FE_HAS_CARRIER;
+		if ((t & 0x80) == 0x80)
+			*fe_status |= FE_HAS_VITERBI | FE_HAS_SYNC |
+				FE_HAS_LOCK;
+	} else {
+		if ((t & 0x80) == 0x80)
+			*fe_status |= FE_HAS_SIGNAL | FE_HAS_CARRIER |
+				FE_HAS_VITERBI | FE_HAS_SYNC | FE_HAS_LOCK;
+	}
+
+	/* success */
+	dprintk("%s: fe_status=0x%x\n", __func__, *fe_status);
+	return 0;
+}
+
+static int lgs8gxx_read_signal_agc(struct lgs8gxx_state *priv, u16 *signal)
+{
+	u16 v;
+	u8 agc_lvl[2], cat;
+
+	dprintk("%s()\n", __func__);
+	lgs8gxx_read_reg(priv, 0x3F, &agc_lvl[0]);
+	lgs8gxx_read_reg(priv, 0x3E, &agc_lvl[1]);
+
+	v = agc_lvl[0];
+	v <<= 8;
+	v |= agc_lvl[1];
+
+	dprintk("agc_lvl: 0x%04X\n", v);
+
+	if (v < 0x100)
+		cat = 0;
+	else if (v < 0x190)
+		cat = 5;
+	else if (v < 0x2A8)
+		cat = 4;
+	else if (v < 0x381)
+		cat = 3;
+	else if (v < 0x400)
+		cat = 2;
+	else if (v == 0x400)
+		cat = 1;
+	else
+		cat = 0;
+
+	*signal = cat;
+
+	return 0;
+}
+
+static int lgs8913_read_signal_strength(struct lgs8gxx_state *priv, u16 *signal)
+{
+	u8 t; s8 ret;
+	s16 max_strength = 0;
+	u8 str;
+	u16 i, gi = priv->curr_gi;
+
+	dprintk("%s\n", __func__);
+
+	ret = lgs8gxx_read_reg(priv, 0x4B, &t);
+	if (ret != 0)
+		return -EIO;
+
+	if (fake_signal_str) {
+		if ((t & 0xC0) == 0xC0) {
+			dprintk("Fake signal strength as 50\n");
+			*signal = 0x32;
+		} else
+			*signal = 0;
+		return 0;
+	}
+
+	dprintk("gi = %d\n", gi);
+	for (i = 0; i < gi; i++) {
+
+		if ((i & 0xFF) == 0)
+			lgs8gxx_write_reg(priv, 0x84, 0x03 & (i >> 8));
+		lgs8gxx_write_reg(priv, 0x83, i & 0xFF);
+
+		lgs8gxx_read_reg(priv, 0x94, &str);
+		if (max_strength < str)
+			max_strength = str;
+	}
+
+	*signal = max_strength;
+	dprintk("%s: signal=0x%02X\n", __func__, *signal);
+
+	lgs8gxx_read_reg(priv, 0x95, &t);
+	dprintk("%s: AVG Noise=0x%02X\n", __func__, t);
+
+	return 0;
+}
+
+static int lgs8gxx_read_signal_strength(struct dvb_frontend *fe, u16 *signal)
+{
+	struct lgs8gxx_state *priv = fe->demodulator_priv;
+
+	if (priv->config->prod == LGS8GXX_PROD_LGS8913)
+		return lgs8913_read_signal_strength(priv, signal);
+	else
+		return lgs8gxx_read_signal_agc(priv, signal);
+}
+
+static int lgs8gxx_read_snr(struct dvb_frontend *fe, u16 *snr)
+{
+	struct lgs8gxx_state *priv = fe->demodulator_priv;
+	u8 t;
+	*snr = 0;
+
+	lgs8gxx_read_reg(priv, 0x95, &t);
+	dprintk("AVG Noise=0x%02X\n", t);
+	*snr = 256 - t;
+	*snr <<= 8;
+	dprintk("snr=0x%x\n", *snr);
+
+	return 0;
+}
+
+static int lgs8gxx_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks)
+{
+	*ucblocks = 0;
+	dprintk("%s: ucblocks=0x%x\n", __func__, *ucblocks);
+	return 0;
+}
+
+static int lgs8gxx_read_ber(struct dvb_frontend *fe, u32 *ber)
+{
+	struct lgs8gxx_state *priv = fe->demodulator_priv;
+	u8 r0, r1, r2, r3;
+	u32 total_cnt, err_cnt;
+
+	dprintk("%s\n", __func__);
+
+	lgs8gxx_write_reg(priv, 0xc6, 0x01);
+	lgs8gxx_write_reg(priv, 0xc6, 0x41);
+	lgs8gxx_write_reg(priv, 0xc6, 0x01);
+
+	msleep(200);
+
+	lgs8gxx_write_reg(priv, 0xc6, 0x81);
+	lgs8gxx_read_reg(priv, 0xd0, &r0);
+	lgs8gxx_read_reg(priv, 0xd1, &r1);
+	lgs8gxx_read_reg(priv, 0xd2, &r2);
+	lgs8gxx_read_reg(priv, 0xd3, &r3);
+	total_cnt = (r3 << 24) | (r2 << 16) | (r1 << 8) | (r0);
+	lgs8gxx_read_reg(priv, 0xd4, &r0);
+	lgs8gxx_read_reg(priv, 0xd5, &r1);
+	lgs8gxx_read_reg(priv, 0xd6, &r2);
+	lgs8gxx_read_reg(priv, 0xd7, &r3);
+	err_cnt = (r3 << 24) | (r2 << 16) | (r1 << 8) | (r0);
+	dprintk("error=%d total=%d\n", err_cnt, total_cnt);
+
+	if (total_cnt == 0)
+		*ber = 0;
+	else
+		*ber = err_cnt * 100 / total_cnt;
+
+	dprintk("%s: ber=0x%x\n", __func__, *ber);
+	return 0;
+}
+
+static int lgs8gxx_i2c_gate_ctrl(struct dvb_frontend *fe, int enable)
+{
+	struct lgs8gxx_state *priv = fe->demodulator_priv;
+
+	if (priv->config->tuner_address == 0)
+		return 0;
+	if (enable) {
+		u8 v = 0x80 | priv->config->tuner_address;
+		return lgs8gxx_write_reg(priv, 0x01, v);
+	}
+	return lgs8gxx_write_reg(priv, 0x01, 0);
+}
+
+static struct dvb_frontend_ops lgs8gxx_ops = {
+	.info = {
+		.name = "Legend Silicon LGS8913/LGS8GXX DMB-TH",
+		.type = FE_OFDM,
+		.frequency_min = 474000000,
+		.frequency_max = 858000000,
+		.frequency_stepsize = 10000,
+		.caps =
+			FE_CAN_FEC_AUTO |
+			FE_CAN_QAM_AUTO |
+			FE_CAN_TRANSMISSION_MODE_AUTO |
+			FE_CAN_GUARD_INTERVAL_AUTO
+	},
+
+	.release = lgs8gxx_release,
+
+	.init = lgs8gxx_init,
+	.write = lgs8gxx_write,
+	.i2c_gate_ctrl = lgs8gxx_i2c_gate_ctrl,
+
+	.set_frontend = lgs8gxx_set_fe,
+	.get_frontend = lgs8gxx_get_fe,
+	.get_tune_settings = lgs8gxx_get_tune_settings,
+
+	.read_status = lgs8gxx_read_status,
+	.read_ber = lgs8gxx_read_ber,
+	.read_signal_strength = lgs8gxx_read_signal_strength,
+	.read_snr = lgs8gxx_read_snr,
+	.read_ucblocks = lgs8gxx_read_ucblocks,
+};
+
+struct dvb_frontend *lgs8gxx_attach(const struct lgs8gxx_config *config,
+	struct i2c_adapter *i2c)
+{
+	struct lgs8gxx_state *priv = NULL;
+	u8 data = 0;
+
+	dprintk("%s()\n", __func__);
+
+	if (config == NULL || i2c == NULL)
+		return NULL;
+
+	priv = kzalloc(sizeof(struct lgs8gxx_state), GFP_KERNEL);
+	if (priv == NULL)
+		goto error_out;
+
+	priv->config = config;
+	priv->i2c = i2c;
+
+	/* check if the demod is there */
+	if (lgs8gxx_read_reg(priv, 0, &data) != 0) {
+		dprintk("%s lgs8gxx not found at i2c addr 0x%02X\n",
+			__func__, priv->config->demod_address);
+		goto error_out;
+	}
+
+	lgs8gxx_read_reg(priv, 1, &data);
+
+	memcpy(&priv->frontend.ops, &lgs8gxx_ops,
+	       sizeof(struct dvb_frontend_ops));
+	priv->frontend.demodulator_priv = priv;
+
+	return &priv->frontend;
+
+error_out:
+	dprintk("%s() error_out\n", __func__);
+	kfree(priv);
+	return NULL;
+
+}
+EXPORT_SYMBOL(lgs8gxx_attach);
+
+MODULE_DESCRIPTION("Legend Silicon LGS8913/LGS8GXX DMB-TH demodulator driver");
+MODULE_AUTHOR("David T. L. Wong <davidtlwong@gmail.com>");
+MODULE_LICENSE("GPL");