Merge branch 'topic/r820t' into patchwork

* topic/r820t: (31 commits)
  [media] r820t: Don't divide the IF by two
  [media] r820t: disable auto gain/VGA setting
  [media] rtl2832: Fix IF calculus
  [media] r820t: put it into automatic gain mode
  [media] r820t: Fix hp_cor filter mask
  [media] r820t: fix PLL calculus
  [media] r820t: Don't put it in standby if not initialized yet
  [media] r820t: avoid rewrite all regs when not needed
  [media] r820t: Allow disabling IMR callibration
  [media] r820t: add a commented code for GPIO
  [media] r820t: add IMR calibrate code
  [media] r820t: proper initialize the PLL register
  [media] r820t: use usleep_range()
  [media] r820t: fix prefix of the r820t_read() function
  [media] r820t: split the function that read cached regs
  [media] r820t: better report signal strength
  [media] r820t: add support for diplexer
  [media] r820t: Show the read data in the bit-reversed order
  [media] r820t: use the second table for 7MHz
  [media] r820t: Invert bits for read ops
  ...

10 files changed, 2548 insertions, 20 deletions

diff --git a/drivers/media/dvb-frontends/rtl2832.c b/drivers/media/dvb-frontends/rtl2832.c
index 73887690b046..facb84841518 100644
--- a/drivers/media/dvb-frontends/rtl2832.c
+++ b/drivers/media/dvb-frontends/rtl2832.c
@@ -380,13 +380,41 @@ err:
 	return ret;
 }
 
-static int rtl2832_init(struct dvb_frontend *fe)
+
+static int rtl2832_set_if(struct dvb_frontend *fe, u32 if_freq)
 {
 	struct rtl2832_priv *priv = fe->demodulator_priv;
-	int i, ret, len;
-	u8 en_bbin;
+	int ret;
 	u64 pset_iffreq;
+	u8 en_bbin = (if_freq == 0 ? 0x1 : 0x0);
+
+	/*
+	* PSET_IFFREQ = - floor((IfFreqHz % CrystalFreqHz) * pow(2, 22)
+	*		/ CrystalFreqHz)
+	*/
+
+	pset_iffreq = if_freq % priv->cfg.xtal;
+	pset_iffreq *= 0x400000;
+	pset_iffreq = div_u64(pset_iffreq, priv->cfg.xtal);
+	pset_iffreq = -pset_iffreq;
+	pset_iffreq = pset_iffreq & 0x3fffff;
+	dev_dbg(&priv->i2c->dev, "%s: if_frequency=%d pset_iffreq=%08x\n",
+			__func__, if_freq, (unsigned)pset_iffreq);
+
+	ret = rtl2832_wr_demod_reg(priv, DVBT_EN_BBIN, en_bbin);
+	if (ret)
+		return ret;
+
+	ret = rtl2832_wr_demod_reg(priv, DVBT_PSET_IFFREQ, pset_iffreq);
+
+	return (ret);
+}
+
+static int rtl2832_init(struct dvb_frontend *fe)
+{
+	struct rtl2832_priv *priv = fe->demodulator_priv;
 	const struct rtl2832_reg_value *init;
+	int i, ret, len;
 
 	/* initialization values for the demodulator registers */
 	struct rtl2832_reg_value rtl2832_initial_regs[] = {
@@ -432,22 +460,10 @@ static int rtl2832_init(struct dvb_frontend *fe)
 		{DVBT_TR_THD_SET2,		0x6},
 		{DVBT_TRK_KC_I2,		0x5},
 		{DVBT_CR_THD_SET2,		0x1},
-		{DVBT_SPEC_INV,			0x0},
 	};
 
 	dev_dbg(&priv->i2c->dev, "%s:\n", __func__);
 
-	en_bbin = (priv->cfg.if_dvbt == 0 ? 0x1 : 0x0);
-
-	/*
-	* PSET_IFFREQ = - floor((IfFreqHz % CrystalFreqHz) * pow(2, 22)
-	*		/ CrystalFreqHz)
-	*/
-	pset_iffreq = priv->cfg.if_dvbt % priv->cfg.xtal;
-	pset_iffreq *= 0x400000;
-	pset_iffreq = div_u64(pset_iffreq, priv->cfg.xtal);
-	pset_iffreq = pset_iffreq & 0x3fffff;
-
 	for (i = 0; i < ARRAY_SIZE(rtl2832_initial_regs); i++) {
 		ret = rtl2832_wr_demod_reg(priv, rtl2832_initial_regs[i].reg,
 			rtl2832_initial_regs[i].value);
@@ -472,6 +488,10 @@ static int rtl2832_init(struct dvb_frontend *fe)
 		len = ARRAY_SIZE(rtl2832_tuner_init_e4000);
 		init = rtl2832_tuner_init_e4000;
 		break;
+	case RTL2832_TUNER_R820T:
+		len = ARRAY_SIZE(rtl2832_tuner_init_r820t);
+		init = rtl2832_tuner_init_r820t;
+		break;
 	default:
 		ret = -EINVAL;
 		goto err;
@@ -483,14 +503,26 @@ static int rtl2832_init(struct dvb_frontend *fe)
 			goto err;
 	}
 
-	/* if frequency settings */
-	ret = rtl2832_wr_demod_reg(priv, DVBT_EN_BBIN, en_bbin);
+	if (!fe->ops.tuner_ops.get_if_frequency) {
+		ret = rtl2832_set_if(fe, priv->cfg.if_dvbt);
 		if (ret)
 			goto err;
+	}
 
-	ret = rtl2832_wr_demod_reg(priv, DVBT_PSET_IFFREQ, pset_iffreq);
-		if (ret)
-			goto err;
+	/*
+	 * r820t NIM code does a software reset here at the demod -
+	 * may not be needed, as there's already a software reset at set_params()
+	 */
+#if 1
+	/* soft reset */
+	ret = rtl2832_wr_demod_reg(priv, DVBT_SOFT_RST, 0x1);
+	if (ret)
+		goto err;
+
+	ret = rtl2832_wr_demod_reg(priv, DVBT_SOFT_RST, 0x0);
+	if (ret)
+		goto err;
+#endif
 
 	priv->sleeping = false;
 
@@ -564,6 +596,19 @@ static int rtl2832_set_frontend(struct dvb_frontend *fe)
 	if (fe->ops.tuner_ops.set_params)
 		fe->ops.tuner_ops.set_params(fe);
 
+	/* If the frontend has get_if_frequency(), use it */
+	if (fe->ops.tuner_ops.get_if_frequency) {
+		u32 if_freq;
+
+		ret = fe->ops.tuner_ops.get_if_frequency(fe, &if_freq);
+		if (ret)
+			goto err;
+
+		ret = rtl2832_set_if(fe, if_freq);
+		if (ret)
+			goto err;
+	}
+
 	switch (c->bandwidth_hz) {
 	case 6000000:
 		i = 0;
diff --git a/drivers/media/dvb-frontends/rtl2832.h b/drivers/media/dvb-frontends/rtl2832.h
index fefba0e9ba30..91b2dcf5a6ea 100644
--- a/drivers/media/dvb-frontends/rtl2832.h
+++ b/drivers/media/dvb-frontends/rtl2832.h
@@ -52,6 +52,7 @@ struct rtl2832_config {
 #define RTL2832_TUNER_FC0012    0x26
 #define RTL2832_TUNER_E4000     0x27
 #define RTL2832_TUNER_FC0013    0x29
+#define RTL2832_TUNER_R820T	0x2a
 	u8 tuner;
 };
 
diff --git a/drivers/media/dvb-frontends/rtl2832_priv.h b/drivers/media/dvb-frontends/rtl2832_priv.h
index 7d97ce9d2193..b5f2b80092ee 100644
--- a/drivers/media/dvb-frontends/rtl2832_priv.h
+++ b/drivers/media/dvb-frontends/rtl2832_priv.h
@@ -267,6 +267,7 @@ static const struct rtl2832_reg_value rtl2832_tuner_init_tua9001[] = {
 	{DVBT_OPT_ADC_IQ,                0x1},
 	{DVBT_AD_AVI,                    0x0},
 	{DVBT_AD_AVQ,                    0x0},
+	{DVBT_SPEC_INV,			 0x0},
 };
 
 static const struct rtl2832_reg_value rtl2832_tuner_init_fc0012[] = {
@@ -300,6 +301,7 @@ static const struct rtl2832_reg_value rtl2832_tuner_init_fc0012[] = {
 	{DVBT_GI_PGA_STATE,              0x0},
 	{DVBT_EN_AGC_PGA,                0x1},
 	{DVBT_IF_AGC_MAN,                0x0},
+	{DVBT_SPEC_INV,			 0x0},
 };
 
 static const struct rtl2832_reg_value rtl2832_tuner_init_e4000[] = {
@@ -337,6 +339,32 @@ static const struct rtl2832_reg_value rtl2832_tuner_init_e4000[] = {
 	{DVBT_REG_MONSEL,                0x1},
 	{DVBT_REG_MON,                   0x1},
 	{DVBT_REG_4MSEL,                 0x0},
+	{DVBT_SPEC_INV,			 0x0},
+};
+
+static const struct rtl2832_reg_value rtl2832_tuner_init_r820t[] = {
+	{DVBT_DAGC_TRG_VAL,		0x39},
+	{DVBT_AGC_TARG_VAL_0,		0x0},
+	{DVBT_AGC_TARG_VAL_8_1,		0x40},
+	{DVBT_AAGC_LOOP_GAIN,		0x16},
+	{DVBT_LOOP_GAIN2_3_0,		0x8},
+	{DVBT_LOOP_GAIN2_4,		0x1},
+	{DVBT_LOOP_GAIN3,		0x18},
+	{DVBT_VTOP1,			0x35},
+	{DVBT_VTOP2,			0x21},
+	{DVBT_VTOP3,			0x21},
+	{DVBT_KRF1,			0x0},
+	{DVBT_KRF2,			0x40},
+	{DVBT_KRF3,			0x10},
+	{DVBT_KRF4,			0x10},
+	{DVBT_IF_AGC_MIN,		0x80},
+	{DVBT_IF_AGC_MAX,		0x7f},
+	{DVBT_RF_AGC_MIN,		0x80},
+	{DVBT_RF_AGC_MAX,		0x7f},
+	{DVBT_POLAR_RF_AGC,		0x0},
+	{DVBT_POLAR_IF_AGC,		0x0},
+	{DVBT_AD7_SETTING,		0xe9f4},
+	{DVBT_SPEC_INV,			0x1},
 };
 
 #endif /* RTL2832_PRIV_H */
diff --git a/drivers/media/tuners/Kconfig b/drivers/media/tuners/Kconfig
index ffabd66dd14d..f6768cad001a 100644
--- a/drivers/media/tuners/Kconfig
+++ b/drivers/media/tuners/Kconfig
@@ -248,4 +248,11 @@ config MEDIA_TUNER_IT913X
 	default m if !MEDIA_SUBDRV_AUTOSELECT
 	help
 	  ITE Tech IT913x silicon tuner driver.
+
+config MEDIA_TUNER_R820T
+	tristate "Rafael Micro R820T silicon tuner"
+	depends on MEDIA_SUPPORT && I2C
+	default m if !MEDIA_SUBDRV_AUTOSELECT
+	help
+	  Rafael Micro R820T silicon tuner driver.
 endmenu
diff --git a/drivers/media/tuners/Makefile b/drivers/media/tuners/Makefile
index 2ebe4b725b51..308f108eadba 100644
--- a/drivers/media/tuners/Makefile
+++ b/drivers/media/tuners/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_MEDIA_TUNER_FC0011) += fc0011.o
 obj-$(CONFIG_MEDIA_TUNER_FC0012) += fc0012.o
 obj-$(CONFIG_MEDIA_TUNER_FC0013) += fc0013.o
 obj-$(CONFIG_MEDIA_TUNER_IT913X) += tuner_it913x.o
+obj-$(CONFIG_MEDIA_TUNER_R820T) += r820t.o
 
 ccflags-y += -I$(srctree)/drivers/media/dvb-core
 ccflags-y += -I$(srctree)/drivers/media/dvb-frontends
diff --git a/drivers/media/tuners/r820t.c b/drivers/media/tuners/r820t.c
new file mode 100644
index 000000000000..905a10615e52
--- /dev/null
+++ b/drivers/media/tuners/r820t.c
@@ -0,0 +1,2352 @@
+/*
+ * Rafael Micro R820T driver
+ *
+ * Copyright (C) 2013 Mauro Carvalho Chehab <mchehab@redhat.com>
+ *
+ * This driver was written from scratch, based on an existing driver
+ * that it is part of rtl-sdr git tree, released under GPLv2:
+ *	https://groups.google.com/forum/#!topic/ultra-cheap-sdr/Y3rBEOFtHug
+ *	https://github.com/n1gp/gr-baz
+ *
+ * From what I understood from the threads, the original driver was converted
+ * to userspace from a Realtek tree. I couldn't find the original tree.
+ * However, the original driver look awkward on my eyes. So, I decided to
+ * write a new version from it from the scratch, while trying to reproduce
+ * everything found there.
+ *
+ * TODO:
+ *	After locking, the original driver seems to have some routines to
+ *		improve reception. This was not implemented here yet.
+ *
+ *	RF Gain set/get is not implemented.
+ *
+ *    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.
+ *
+ */
+
+#include <linux/videodev2.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/bitrev.h>
+
+#include "tuner-i2c.h"
+#include "r820t.h"
+
+/*
+ * FIXME: I think that there are only 32 registers, but better safe than
+ *	  sorry. After finishing the driver, we may review it.
+ */
+#define REG_SHADOW_START	5
+#define NUM_REGS		27
+#define NUM_IMR			5
+#define IMR_TRIAL		9
+
+#define VER_NUM  49
+
+static int debug;
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug, "enable verbose debug messages");
+
+static int no_imr_cal;
+module_param(no_imr_cal, int, 0444);
+MODULE_PARM_DESC(no_imr_cal, "Disable IMR calibration at module init");
+
+
+/*
+ * enums and structures
+ */
+
+enum xtal_cap_value {
+	XTAL_LOW_CAP_30P = 0,
+	XTAL_LOW_CAP_20P,
+	XTAL_LOW_CAP_10P,
+	XTAL_LOW_CAP_0P,
+	XTAL_HIGH_CAP_0P
+};
+
+struct r820t_sect_type {
+	u8	phase_y;
+	u8	gain_x;
+	u16	value;
+};
+
+struct r820t_priv {
+	struct list_head		hybrid_tuner_instance_list;
+	const struct r820t_config	*cfg;
+	struct tuner_i2c_props		i2c_props;
+	struct mutex			lock;
+
+	u8				regs[NUM_REGS];
+	u8				buf[NUM_REGS + 1];
+	enum xtal_cap_value		xtal_cap_sel;
+	u16				pll;	/* kHz */
+	u32				int_freq;
+	u8				fil_cal_code;
+	bool				imr_done;
+	bool				has_lock;
+	bool				init_done;
+	struct r820t_sect_type		imr_data[NUM_IMR];
+
+	/* Store current mode */
+	u32				delsys;
+	enum v4l2_tuner_type		type;
+	v4l2_std_id			std;
+	u32				bw;	/* in MHz */
+};
+
+struct r820t_freq_range {
+	u32	freq;
+	u8	open_d;
+	u8	rf_mux_ploy;
+	u8	tf_c;
+	u8	xtal_cap20p;
+	u8	xtal_cap10p;
+	u8	xtal_cap0p;
+	u8	imr_mem;		/* Not used, currently */
+};
+
+#define VCO_POWER_REF   0x02
+#define DIP_FREQ	32000000
+
+/*
+ * Static constants
+ */
+
+static LIST_HEAD(hybrid_tuner_instance_list);
+static DEFINE_MUTEX(r820t_list_mutex);
+
+/* Those initial values start from REG_SHADOW_START */
+static const u8 r820t_init_array[NUM_REGS] = {
+	0x83, 0x32, 0x75,			/* 05 to 07 */
+	0xc0, 0x40, 0xd6, 0x6c,			/* 08 to 0b */
+	0xf5, 0x63, 0x75, 0x68,			/* 0c to 0f */
+	0x6c, 0x83, 0x80, 0x00,			/* 10 to 13 */
+	0x0f, 0x00, 0xc0, 0x30,			/* 14 to 17 */
+	0x48, 0xcc, 0x60, 0x00,			/* 18 to 1b */
+	0x54, 0xae, 0x4a, 0xc0			/* 1c to 1f */
+};
+
+/* Tuner frequency ranges */
+static const struct r820t_freq_range freq_ranges[] = {
+	{
+		.freq = 0,
+		.open_d = 0x08,		/* low */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0xdf,		/* R27[7:0]  band2,band0 */
+		.xtal_cap20p = 0x02,	/* R16[1:0]  20pF (10)   */
+		.xtal_cap10p = 0x01,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 0,
+	}, {
+		.freq = 50,		/* Start freq, in MHz */
+		.open_d = 0x08,		/* low */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0xbe,		/* R27[7:0]  band4,band1  */
+		.xtal_cap20p = 0x02,	/* R16[1:0]  20pF (10)   */
+		.xtal_cap10p = 0x01,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 0,
+	}, {
+		.freq = 55,		/* Start freq, in MHz */
+		.open_d = 0x08,		/* low */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0x8b,		/* R27[7:0]  band7,band4 */
+		.xtal_cap20p = 0x02,	/* R16[1:0]  20pF (10)   */
+		.xtal_cap10p = 0x01,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 0,
+	}, {
+		.freq = 60,		/* Start freq, in MHz */
+		.open_d = 0x08,		/* low */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0x7b,		/* R27[7:0]  band8,band4 */
+		.xtal_cap20p = 0x02,	/* R16[1:0]  20pF (10)   */
+		.xtal_cap10p = 0x01,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 0,
+	}, {
+		.freq = 65,		/* Start freq, in MHz */
+		.open_d = 0x08,		/* low */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0x69,		/* R27[7:0]  band9,band6 */
+		.xtal_cap20p = 0x02,	/* R16[1:0]  20pF (10)   */
+		.xtal_cap10p = 0x01,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 0,
+	}, {
+		.freq = 70,		/* Start freq, in MHz */
+		.open_d = 0x08,		/* low */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0x58,		/* R27[7:0]  band10,band7 */
+		.xtal_cap20p = 0x02,	/* R16[1:0]  20pF (10)   */
+		.xtal_cap10p = 0x01,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 0,
+	}, {
+		.freq = 75,		/* Start freq, in MHz */
+		.open_d = 0x00,		/* high */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0x44,		/* R27[7:0]  band11,band11 */
+		.xtal_cap20p = 0x02,	/* R16[1:0]  20pF (10)   */
+		.xtal_cap10p = 0x01,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 0,
+	}, {
+		.freq = 80,		/* Start freq, in MHz */
+		.open_d = 0x00,		/* high */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0x44,		/* R27[7:0]  band11,band11 */
+		.xtal_cap20p = 0x02,	/* R16[1:0]  20pF (10)   */
+		.xtal_cap10p = 0x01,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 0,
+	}, {
+		.freq = 90,		/* Start freq, in MHz */
+		.open_d = 0x00,		/* high */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0x34,		/* R27[7:0]  band12,band11 */
+		.xtal_cap20p = 0x01,	/* R16[1:0]  10pF (01)   */
+		.xtal_cap10p = 0x01,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 0,
+	}, {
+		.freq = 100,		/* Start freq, in MHz */
+		.open_d = 0x00,		/* high */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0x34,		/* R27[7:0]  band12,band11 */
+		.xtal_cap20p = 0x01,	/* R16[1:0]  10pF (01)    */
+		.xtal_cap10p = 0x01,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 0,
+	}, {
+		.freq = 110,		/* Start freq, in MHz */
+		.open_d = 0x00,		/* high */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0x24,		/* R27[7:0]  band13,band11 */
+		.xtal_cap20p = 0x01,	/* R16[1:0]  10pF (01)   */
+		.xtal_cap10p = 0x01,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 1,
+	}, {
+		.freq = 120,		/* Start freq, in MHz */
+		.open_d = 0x00,		/* high */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0x24,		/* R27[7:0]  band13,band11 */
+		.xtal_cap20p = 0x01,	/* R16[1:0]  10pF (01)   */
+		.xtal_cap10p = 0x01,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 1,
+	}, {
+		.freq = 140,		/* Start freq, in MHz */
+		.open_d = 0x00,		/* high */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0x14,		/* R27[7:0]  band14,band11 */
+		.xtal_cap20p = 0x01,	/* R16[1:0]  10pF (01)   */
+		.xtal_cap10p = 0x01,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 1,
+	}, {
+		.freq = 180,		/* Start freq, in MHz */
+		.open_d = 0x00,		/* high */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0x13,		/* R27[7:0]  band14,band12 */
+		.xtal_cap20p = 0x00,	/* R16[1:0]  0pF (00)   */
+		.xtal_cap10p = 0x00,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 1,
+	}, {
+		.freq = 220,		/* Start freq, in MHz */
+		.open_d = 0x00,		/* high */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0x13,		/* R27[7:0]  band14,band12 */
+		.xtal_cap20p = 0x00,	/* R16[1:0]  0pF (00)   */
+		.xtal_cap10p = 0x00,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 2,
+	}, {
+		.freq = 250,		/* Start freq, in MHz */
+		.open_d = 0x00,		/* high */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0x11,		/* R27[7:0]  highest,highest */
+		.xtal_cap20p = 0x00,	/* R16[1:0]  0pF (00)   */
+		.xtal_cap10p = 0x00,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 2,
+	}, {
+		.freq = 280,		/* Start freq, in MHz */
+		.open_d = 0x00,		/* high */
+		.rf_mux_ploy = 0x02,	/* R26[7:6]=0 (LPF)  R26[1:0]=2 (low) */
+		.tf_c = 0x00,		/* R27[7:0]  highest,highest */
+		.xtal_cap20p = 0x00,	/* R16[1:0]  0pF (00)   */
+		.xtal_cap10p = 0x00,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 2,
+	}, {
+		.freq = 310,		/* Start freq, in MHz */
+		.open_d = 0x00,		/* high */
+		.rf_mux_ploy = 0x41,	/* R26[7:6]=1 (bypass)  R26[1:0]=1 (middle) */
+		.tf_c = 0x00,		/* R27[7:0]  highest,highest */
+		.xtal_cap20p = 0x00,	/* R16[1:0]  0pF (00)   */
+		.xtal_cap10p = 0x00,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 2,
+	}, {
+		.freq = 450,		/* Start freq, in MHz */
+		.open_d = 0x00,		/* high */
+		.rf_mux_ploy = 0x41,	/* R26[7:6]=1 (bypass)  R26[1:0]=1 (middle) */
+		.tf_c = 0x00,		/* R27[7:0]  highest,highest */
+		.xtal_cap20p = 0x00,	/* R16[1:0]  0pF (00)   */
+		.xtal_cap10p = 0x00,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 3,
+	}, {
+		.freq = 588,		/* Start freq, in MHz */
+		.open_d = 0x00,		/* high */
+		.rf_mux_ploy = 0x40,	/* R26[7:6]=1 (bypass)  R26[1:0]=0 (highest) */
+		.tf_c = 0x00,		/* R27[7:0]  highest,highest */
+		.xtal_cap20p = 0x00,	/* R16[1:0]  0pF (00)   */
+		.xtal_cap10p = 0x00,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 3,
+	}, {
+		.freq = 650,		/* Start freq, in MHz */
+		.open_d = 0x00,		/* high */
+		.rf_mux_ploy = 0x40,	/* R26[7:6]=1 (bypass)  R26[1:0]=0 (highest) */
+		.tf_c = 0x00,		/* R27[7:0]  highest,highest */
+		.xtal_cap20p = 0x00,	/* R16[1:0]  0pF (00)   */
+		.xtal_cap10p = 0x00,
+		.xtal_cap0p = 0x00,
+		.imr_mem = 4,
+	}
+};
+
+static int r820t_xtal_capacitor[][2] = {
+	{ 0x0b, XTAL_LOW_CAP_30P },
+	{ 0x02, XTAL_LOW_CAP_20P },
+	{ 0x01, XTAL_LOW_CAP_10P },
+	{ 0x00, XTAL_LOW_CAP_0P  },
+	{ 0x10, XTAL_HIGH_CAP_0P },
+};
+
+/*
+ * measured with a Racal 6103E GSM test set at 928 MHz with -60 dBm
+ * input power, for raw results see:
+ *	http://steve-m.de/projects/rtl-sdr/gain_measurement/r820t/
+ */
+
+static const int r820t_lna_gain_steps[]  = {
+	0, 9, 13, 40, 38, 13, 31, 22, 26, 31, 26, 14, 19, 5, 35, 13
+};
+
+static const int r820t_mixer_gain_steps[]  = {
+	0, 5, 10, 10, 19, 9, 10, 25, 17, 10, 8, 16, 13, 6, 3, -8
+};
+
+/*
+ * I2C read/write code and shadow registers logic
+ */
+static void shadow_store(struct r820t_priv *priv, u8 reg, const u8 *val,
+			 int len)
+{
+	int r = reg - REG_SHADOW_START;
+
+	if (r < 0) {
+		len += r;
+		r = 0;
+	}
+	if (len <= 0)
+		return;
+	if (len > NUM_REGS)
+		len = NUM_REGS;
+
+	tuner_dbg("%s: prev  reg=%02x len=%d: %*ph\n",
+		  __func__, r + REG_SHADOW_START, len, len, val);
+
+	memcpy(&priv->regs[r], val, len);
+}
+
+static int r820t_write(struct r820t_priv *priv, u8 reg, const u8 *val,
+		       int len)
+{
+	int rc, size, pos = 0;
+
+	/* Store the shadow registers */
+	shadow_store(priv, reg, val, len);
+
+	do {
+		if (len > priv->cfg->max_i2c_msg_len - 1)
+			size = priv->cfg->max_i2c_msg_len - 1;
+		else
+			size = len;
+
+		/* Fill I2C buffer */
+		priv->buf[0] = reg;
+		memcpy(&priv->buf[1], &val[pos], size);
+
+		rc = tuner_i2c_xfer_send(&priv->i2c_props, priv->buf, size + 1);
+		if (rc != size + 1) {
+			tuner_info("%s: i2c wr failed=%d reg=%02x len=%d: %*ph\n",
+				   __func__, rc, reg, size, size, &priv->buf[1]);
+			if (rc < 0)
+				return rc;
+			return -EREMOTEIO;
+		}
+		tuner_dbg("%s: i2c wr reg=%02x len=%d: %*ph\n",
+			  __func__, reg, size, size, &priv->buf[1]);
+
+		reg += size;
+		len -= size;
+		pos += size;
+	} while (len > 0);
+
+	return 0;
+}
+
+static int r820t_write_reg(struct r820t_priv *priv, u8 reg, u8 val)
+{
+	return r820t_write(priv, reg, &val, 1);
+}
+
+static int r820t_read_cache_reg(struct r820t_priv *priv, int reg)
+{
+	reg -= REG_SHADOW_START;
+
+	if (reg >= 0 && reg < NUM_REGS)
+		return priv->regs[reg];
+	else
+		return -EINVAL;
+}
+
+static int r820t_write_reg_mask(struct r820t_priv *priv, u8 reg, u8 val,
+				u8 bit_mask)
+{
+	int rc = r820t_read_cache_reg(priv, reg);
+
+	if (rc < 0)
+		return rc;
+
+	val = (rc & ~bit_mask) | (val & bit_mask);
+
+	return r820t_write(priv, reg, &val, 1);
+}
+
+static int r820t_read(struct r820t_priv *priv, u8 reg, u8 *val, int len)
+{
+	int rc, i;
+	u8 *p = &priv->buf[1];
+
+	priv->buf[0] = reg;
+
+	rc = tuner_i2c_xfer_send_recv(&priv->i2c_props, priv->buf, 1, p, len);
+	if (rc != len) {
+		tuner_info("%s: i2c rd failed=%d reg=%02x len=%d: %*ph\n",
+			   __func__, rc, reg, len, len, p);
+		if (rc < 0)
+			return rc;
+		return -EREMOTEIO;
+	}
+
+	/* Copy data to the output buffer */
+	for (i = 0; i < len; i++)
+		val[i] = bitrev8(p[i]);
+
+	tuner_dbg("%s: i2c rd reg=%02x len=%d: %*ph\n",
+		  __func__, reg, len, len, val);
+
+	return 0;
+}
+
+/*
+ * r820t tuning logic
+ */
+
+static int r820t_set_mux(struct r820t_priv *priv, u32 freq)
+{
+	const struct r820t_freq_range *range;
+	int i, rc;
+	u8 val, reg08, reg09;
+
+	/* Get the proper frequency range */
+	freq = freq / 1000000;
+	for (i = 0; i < ARRAY_SIZE(freq_ranges) - 1; i++) {
+		if (freq < freq_ranges[i + 1].freq)
+			break;
+	}
+	range = &freq_ranges[i];
+
+	tuner_dbg("set r820t range#%d for frequency %d MHz\n", i, freq);
+
+	/* Open Drain */
+	rc = r820t_write_reg_mask(priv, 0x17, range->open_d, 0x08);
+	if (rc < 0)
+		return rc;
+
+	/* RF_MUX,Polymux */
+	rc = r820t_write_reg_mask(priv, 0x1a, range->rf_mux_ploy, 0xc3);
+	if (rc < 0)
+		return rc;
+
+	/* TF BAND */
+	rc = r820t_write_reg(priv, 0x1b, range->tf_c);
+	if (rc < 0)
+		return rc;
+
+	/* XTAL CAP & Drive */
+	switch (priv->xtal_cap_sel) {
+	case XTAL_LOW_CAP_30P:
+	case XTAL_LOW_CAP_20P:
+		val = range->xtal_cap20p | 0x08;
+		break;
+	case XTAL_LOW_CAP_10P:
+		val = range->xtal_cap10p | 0x08;
+		break;
+	case XTAL_HIGH_CAP_0P:
+		val = range->xtal_cap0p | 0x00;
+		break;
+	default:
+	case XTAL_LOW_CAP_0P:
+		val = range->xtal_cap0p | 0x08;
+		break;
+	}
+	rc = r820t_write_reg_mask(priv, 0x10, val, 0x0b);
+	if (rc < 0)
+		return rc;
+
+	if (priv->imr_done) {
+		reg08 = priv->imr_data[range->imr_mem].gain_x;
+		reg09 = priv->imr_data[range->imr_mem].phase_y;
+	} else {
+		reg08 = 0;
+		reg09 = 0;
+	}
+	rc = r820t_write_reg_mask(priv, 0x08, reg08, 0x3f);
+	if (rc < 0)
+		return rc;
+
+	rc = r820t_write_reg_mask(priv, 0x09, reg09, 0x3f);
+
+	return rc;
+}
+
+static int r820t_set_pll(struct r820t_priv *priv, enum v4l2_tuner_type type,
+			 u32 freq)
+{
+	u32 vco_freq;
+	int rc, i;
+	unsigned sleep_time = 10000;
+	u32 vco_fra;		/* VCO contribution by SDM (kHz) */
+	u32 vco_min  = 1770000;
+	u32 vco_max  = vco_min * 2;
+	u32 pll_ref;
+	u16 n_sdm = 2;
+	u16 sdm = 0;
+	u8 mix_div = 2;
+	u8 div_buf = 0;
+	u8 div_num = 0;
+	u8 refdiv2 = 0;
+	u8 ni, si, nint, vco_fine_tune, val;
+	u8 data[5];
+
+	/* Frequency in kHz */
+	freq = freq / 1000;
+	pll_ref = priv->cfg->xtal / 1000;
+
+#if 0
+	/* Doesn't exist on rtl-sdk, and on field tests, caused troubles */
+	if ((priv->cfg->rafael_chip == CHIP_R620D) ||
+	   (priv->cfg->rafael_chip == CHIP_R828D) ||
+	   (priv->cfg->rafael_chip == CHIP_R828)) {
+		/* ref set refdiv2, reffreq = Xtal/2 on ATV application */
+		if (type != V4L2_TUNER_DIGITAL_TV) {
+			pll_ref /= 2;
+			refdiv2 = 0x10;
+			sleep_time = 20000;
+		}
+	} else {
+		if (priv->cfg->xtal > 24000000) {
+			pll_ref /= 2;
+			refdiv2 = 0x10;
+		}
+	}
+#endif
+
+	rc = r820t_write_reg_mask(priv, 0x10, refdiv2, 0x10);
+	if (rc < 0)
+		return rc;
+
+	/* set pll autotune = 128kHz */
+	rc = r820t_write_reg_mask(priv, 0x1a, 0x00, 0x0c);
+	if (rc < 0)
+		return rc;
+
+	/* set VCO current = 100 */
+	rc = r820t_write_reg_mask(priv, 0x12, 0x80, 0xe0);
+	if (rc < 0)
+		return rc;
+
+	/* Calculate divider */
+	while (mix_div <= 64) {
+		if (((freq * mix_div) >= vco_min) &&
+		   ((freq * mix_div) < vco_max)) {
+			div_buf = mix_div;
+			while (div_buf > 2) {
+				div_buf = div_buf >> 1;
+				div_num++;
+			}
+			break;
+		}
+		mix_div = mix_div << 1;
+	}
+
+	rc = r820t_read(priv, 0x00, data, sizeof(data));
+	if (rc < 0)
+		return rc;
+
+	vco_fine_tune = (data[4] & 0x30) >> 4;
+
+	if (vco_fine_tune > VCO_POWER_REF)
+		div_num = div_num - 1;
+	else if (vco_fine_tune < VCO_POWER_REF)
+		div_num = div_num + 1;
+
+	rc = r820t_write_reg_mask(priv, 0x10, div_num << 5, 0xe0);
+	if (rc < 0)
+		return rc;
+
+	vco_freq = freq * mix_div;
+	nint = vco_freq / (2 * pll_ref);
+	vco_fra = vco_freq - 2 * pll_ref * nint;
+
+	/* boundary spur prevention */
+	if (vco_fra < pll_ref / 64) {
+		vco_fra = 0;
+	} else if (vco_fra > pll_ref * 127 / 64) {
+		vco_fra = 0;
+		nint++;
+	} else if ((vco_fra > pll_ref * 127 / 128) && (vco_fra < pll_ref)) {
+		vco_fra = pll_ref * 127 / 128;
+	} else if ((vco_fra > pll_ref) && (vco_fra < pll_ref * 129 / 128)) {
+		vco_fra = pll_ref * 129 / 128;
+	}
+
+	if (nint > 63) {
+		tuner_info("No valid PLL values for %u kHz!\n", freq);
+		return -EINVAL;
+	}
+
+	ni = (nint - 13) / 4;
+	si = nint - 4 * ni - 13;
+
+	rc = r820t_write_reg(priv, 0x14, ni + (si << 6));
+	if (rc < 0)
+		return rc;
+
+	/* pw_sdm */
+	if (!vco_fra)
+		val = 0x08;
+	else
+		val = 0x00;
+
+	rc = r820t_write_reg_mask(priv, 0x12, val, 0x08);
+	if (rc < 0)
+		return rc;
+
+	/* sdm calculator */
+	while (vco_fra > 1) {
+		if (vco_fra > (2 * pll_ref / n_sdm)) {
+			sdm = sdm + 32768 / (n_sdm / 2);
+			vco_fra = vco_fra - 2 * pll_ref / n_sdm;
+			if (n_sdm >= 0x8000)
+				break;
+		}
+		n_sdm = n_sdm << 1;
+	}
+
+	tuner_dbg("freq %d kHz, pll ref %d%s, sdm=0x%04x\n",
+		  freq, pll_ref, refdiv2 ? " / 2" : "", sdm);
+
+	rc = r820t_write_reg(priv, 0x16, sdm >> 8);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg(priv, 0x15, sdm & 0xff);
+	if (rc < 0)
+		return rc;
+
+	for (i = 0; i < 2; i++) {
+		usleep_range(sleep_time, sleep_time + 1000);
+
+		/* Check if PLL has locked */
+		rc = r820t_read(priv, 0x00, data, 3);
+		if (rc < 0)
+			return rc;
+		if (data[2] & 0x40)
+			break;
+
+		if (!i) {
+			/* Didn't lock. Increase VCO current */
+			rc = r820t_write_reg_mask(priv, 0x12, 0x60, 0xe0);
+			if (rc < 0)
+				return rc;
+		}
+	}
+
+	if (!(data[2] & 0x40)) {
+		priv->has_lock = false;
+		return 0;
+	}
+
+	priv->has_lock = true;
+	tuner_dbg("tuner has lock at frequency %d kHz\n", freq);
+
+	/* set pll autotune = 8kHz */
+	rc = r820t_write_reg_mask(priv, 0x1a, 0x08, 0x08);
+
+	return rc;
+}
+
+static int r820t_sysfreq_sel(struct r820t_priv *priv, u32 freq,
+			     enum v4l2_tuner_type type,
+			     v4l2_std_id std,
+			     u32 delsys)
+{
+	int rc;
+	u8 mixer_top, lna_top, cp_cur, div_buf_cur, lna_vth_l, mixer_vth_l;
+	u8 air_cable1_in, cable2_in, pre_dect, lna_discharge, filter_cur;
+
+	tuner_dbg("adjusting tuner parameters for the standard\n");
+
+	switch (delsys) {
+	case SYS_DVBT:
+		if ((freq == 506000000) || (freq == 666000000) ||
+		   (freq == 818000000)) {
+			mixer_top = 0x14;	/* mixer top:14 , top-1, low-discharge */
+			lna_top = 0xe5;		/* detect bw 3, lna top:4, predet top:2 */
+			cp_cur = 0x28;		/* 101, 0.2 */
+			div_buf_cur = 0x20;	/* 10, 200u */
+		} else {
+			mixer_top = 0x24;	/* mixer top:13 , top-1, low-discharge */
+			lna_top = 0xe5;		/* detect bw 3, lna top:4, predet top:2 */
+			cp_cur = 0x38;		/* 111, auto */
+			div_buf_cur = 0x30;	/* 11, 150u */
+		}
+		lna_vth_l = 0x53;		/* lna vth 0.84	,  vtl 0.64 */
+		mixer_vth_l = 0x75;		/* mixer vth 1.04, vtl 0.84 */
+		air_cable1_in = 0x00;
+		cable2_in = 0x00;
+		pre_dect = 0x40;
+		lna_discharge = 14;
+		filter_cur = 0x40;		/* 10, low */
+		break;
+	case SYS_DVBT2:
+		mixer_top = 0x24;	/* mixer top:13 , top-1, low-discharge */
+		lna_top = 0xe5;		/* detect bw 3, lna top:4, predet top:2 */
+		lna_vth_l = 0x53;	/* lna vth 0.84	,  vtl 0.64 */
+		mixer_vth_l = 0x75;	/* mixer vth 1.04, vtl 0.84 */
+		air_cable1_in = 0x00;
+		cable2_in = 0x00;
+		pre_dect = 0x40;
+		lna_discharge = 14;
+		cp_cur = 0x38;		/* 111, auto */
+		div_buf_cur = 0x30;	/* 11, 150u */
+		filter_cur = 0x40;	/* 10, low */
+		break;
+	case SYS_ISDBT:
+		mixer_top = 0x24;	/* mixer top:13 , top-1, low-discharge */
+		lna_top = 0xe5;		/* detect bw 3, lna top:4, predet top:2 */
+		lna_vth_l = 0x75;	/* lna vth 1.04	,  vtl 0.84 */
+		mixer_vth_l = 0x75;	/* mixer vth 1.04, vtl 0.84 */
+		air_cable1_in = 0x00;
+		cable2_in = 0x00;
+		pre_dect = 0x40;
+		lna_discharge = 14;
+		cp_cur = 0x38;		/* 111, auto */
+		div_buf_cur = 0x30;	/* 11, 150u */
+		filter_cur = 0x40;	/* 10, low */
+		break;
+	default: /* DVB-T 8M */
+		mixer_top = 0x24;	/* mixer top:13 , top-1, low-discharge */
+		lna_top = 0xe5;		/* detect bw 3, lna top:4, predet top:2 */
+		lna_vth_l = 0x53;	/* lna vth 0.84	,  vtl 0.64 */
+		mixer_vth_l = 0x75;	/* mixer vth 1.04, vtl 0.84 */
+		air_cable1_in = 0x00;
+		cable2_in = 0x00;
+		pre_dect = 0x40;
+		lna_discharge = 14;
+		cp_cur = 0x38;		/* 111, auto */
+		div_buf_cur = 0x30;	/* 11, 150u */
+		filter_cur = 0x40;	/* 10, low */
+		break;
+	}
+
+	if (priv->cfg->use_diplexer &&
+	   ((priv->cfg->rafael_chip == CHIP_R820T) ||
+	   (priv->cfg->rafael_chip == CHIP_R828S) ||
+	   (priv->cfg->rafael_chip == CHIP_R820C))) {
+		if (freq > DIP_FREQ)
+			air_cable1_in = 0x00;
+		else
+			air_cable1_in = 0x60;
+		cable2_in = 0x00;
+	}
+
+	rc = r820t_write_reg_mask(priv, 0x1d, lna_top, 0xc7);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg_mask(priv, 0x1c, mixer_top, 0xf8);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg(priv, 0x0d, lna_vth_l);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg(priv, 0x0e, mixer_vth_l);
+	if (rc < 0)
+		return rc;
+
+	/* Air-IN only for Astrometa */
+	rc = r820t_write_reg_mask(priv, 0x05, air_cable1_in, 0x60);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg_mask(priv, 0x06, cable2_in, 0x08);
+	if (rc < 0)
+		return rc;
+
+	rc = r820t_write_reg_mask(priv, 0x11, cp_cur, 0x38);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg_mask(priv, 0x17, div_buf_cur, 0x30);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg_mask(priv, 0x0a, filter_cur, 0x60);
+	if (rc < 0)
+		return rc;
+	/*
+	 * Original driver initializes regs 0x05 and 0x06 with the
+	 * same value again on this point. Probably, it is just an
+	 * error there
+	 */
+
+	/*
+	 * Set LNA
+	 */
+
+	tuner_dbg("adjusting LNA parameters\n");
+	if (type != V4L2_TUNER_ANALOG_TV) {
+		/* LNA TOP: lowest */
+		rc = r820t_write_reg_mask(priv, 0x1d, 0, 0x38);
+		if (rc < 0)
+			return rc;
+
+		/* 0: normal mode */
+		rc = r820t_write_reg_mask(priv, 0x1c, 0, 0x04);
+		if (rc < 0)
+			return rc;
+
+		/* 0: PRE_DECT off */
+		rc = r820t_write_reg_mask(priv, 0x06, 0, 0x40);
+		if (rc < 0)
+			return rc;
+
+		/* agc clk 250hz */
+		rc = r820t_write_reg_mask(priv, 0x1a, 0x30, 0x30);
+		if (rc < 0)
+			return rc;
+
+		msleep(250);
+
+		/* write LNA TOP = 3 */
+		rc = r820t_write_reg_mask(priv, 0x1d, 0x18, 0x38);
+		if (rc < 0)
+			return rc;
+
+		/*
+		 * write discharge mode
+		 * FIXME: IMHO, the mask here is wrong, but it matches
+		 * what's there at the original driver
+		 */
+		rc = r820t_write_reg_mask(priv, 0x1c, mixer_top, 0x04);
+		if (rc < 0)
+			return rc;
+
+		/* LNA discharge current */
+		rc = r820t_write_reg_mask(priv, 0x1e, lna_discharge, 0x1f);
+		if (rc < 0)
+			return rc;
+
+		/* agc clk 60hz */
+		rc = r820t_write_reg_mask(priv, 0x1a, 0x20, 0x30);
+		if (rc < 0)
+			return rc;
+	} else {
+		/* PRE_DECT off */
+		rc = r820t_write_reg_mask(priv, 0x06, 0, 0x40);
+		if (rc < 0)
+			return rc;
+
+		/* write LNA TOP */
+		rc = r820t_write_reg_mask(priv, 0x1d, lna_top, 0x38);
+		if (rc < 0)
+			return rc;
+
+		/*
+		 * write discharge mode
+		 * FIXME: IMHO, the mask here is wrong, but it matches
+		 * what's there at the original driver
+		 */
+		rc = r820t_write_reg_mask(priv, 0x1c, mixer_top, 0x04);
+		if (rc < 0)
+			return rc;
+
+		/* LNA discharge current */
+		rc = r820t_write_reg_mask(priv, 0x1e, lna_discharge, 0x1f);
+		if (rc < 0)
+			return rc;
+
+		/* agc clk 1Khz, external det1 cap 1u */
+		rc = r820t_write_reg_mask(priv, 0x1a, 0x00, 0x30);
+		if (rc < 0)
+			return rc;
+
+		rc = r820t_write_reg_mask(priv, 0x10, 0x00, 0x04);
+		if (rc < 0)
+			return rc;
+	 }
+	 return 0;
+}
+
+static int r820t_set_tv_standard(struct r820t_priv *priv,
+				 unsigned bw,
+				 enum v4l2_tuner_type type,
+				 v4l2_std_id std, u32 delsys)
+
+{
+	int rc, i;
+	u32 if_khz, filt_cal_lo;
+	u8 data[5], val;
+	u8 filt_gain, img_r, filt_q, hp_cor, ext_enable, loop_through;
+	u8 lt_att, flt_ext_widest, polyfil_cur;
+	bool need_calibration;
+
+	tuner_dbg("selecting the delivery system\n");
+
+	if (delsys == SYS_ISDBT) {
+		if_khz = 4063;
+		filt_cal_lo = 59000;
+		filt_gain = 0x10;	/* +3db, 6mhz on */
+		img_r = 0x00;		/* image negative */
+		filt_q = 0x10;		/* r10[4]:low q(1'b1) */
+		hp_cor = 0x6a;		/* 1.7m disable, +2cap, 1.25mhz */
+		ext_enable = 0x40;	/* r30[6], ext enable; r30[5]:0 ext at lna max */
+		loop_through = 0x00;	/* r5[7], lt on */
+		lt_att = 0x00;		/* r31[7], lt att enable */
+		flt_ext_widest = 0x00;	/* r15[7]: flt_ext_wide off */
+		polyfil_cur = 0x60;	/* r25[6:5]:min */
+	} else {
+		if (bw <= 6) {
+			if_khz = 3570;
+			filt_cal_lo = 56000;	/* 52000->56000 */
+			filt_gain = 0x10;	/* +3db, 6mhz on */
+			img_r = 0x00;		/* image negative */
+			filt_q = 0x10;		/* r10[4]:low q(1'b1) */
+			hp_cor = 0x6b;		/* 1.7m disable, +2cap, 1.0mhz */
+			ext_enable = 0x60;	/* r30[6]=1 ext enable; r30[5]:1 ext at lna max-1 */
+			loop_through = 0x00;	/* r5[7], lt on */
+			lt_att = 0x00;		/* r31[7], lt att enable */
+			flt_ext_widest = 0x00;	/* r15[7]: flt_ext_wide off */
+			polyfil_cur = 0x60;	/* r25[6:5]:min */
+		} else if (bw == 7) {
+#if 0
+			/*
+			 * There are two 7 MHz tables defined on the original
+			 * driver, but just the second one seems to be visible
+			 * by rtl2832. Keep this one here commented, as it
+			 * might be needed in the future
+			 */
+
+			if_khz = 4070;
+			filt_cal_lo = 60000;
+			filt_gain = 0x10;	/* +3db, 6mhz on */
+			img_r = 0x00;		/* image negative */
+			filt_q = 0x10;		/* r10[4]:low q(1'b1) */
+			hp_cor = 0x2b;		/* 1.7m disable, +1cap, 1.0mhz */
+			ext_enable = 0x60;	/* r30[6]=1 ext enable; r30[5]:1 ext at lna max-1 */
+			loop_through = 0x00;	/* r5[7], lt on */
+			lt_att = 0x00;		/* r31[7], lt att enable */
+			flt_ext_widest = 0x00;	/* r15[7]: flt_ext_wide off */
+			polyfil_cur = 0x60;	/* r25[6:5]:min */
+#endif
+			/* 7 MHz, second table */
+			if_khz = 4570;
+			filt_cal_lo = 63000;
+			filt_gain = 0x10;	/* +3db, 6mhz on */
+			img_r = 0x00;		/* image negative */
+			filt_q = 0x10;		/* r10[4]:low q(1'b1) */
+			hp_cor = 0x2a;		/* 1.7m disable, +1cap, 1.25mhz */
+			ext_enable = 0x60;	/* r30[6]=1 ext enable; r30[5]:1 ext at lna max-1 */
+			loop_through = 0x00;	/* r5[7], lt on */
+			lt_att = 0x00;		/* r31[7], lt att enable */
+			flt_ext_widest = 0x00;	/* r15[7]: flt_ext_wide off */
+			polyfil_cur = 0x60;	/* r25[6:5]:min */
+		} else {
+			if_khz = 4570;
+			filt_cal_lo = 68500;
+			filt_gain = 0x10;	/* +3db, 6mhz on */
+			img_r = 0x00;		/* image negative */
+			filt_q = 0x10;		/* r10[4]:low q(1'b1) */
+			hp_cor = 0x0b;		/* 1.7m disable, +0cap, 1.0mhz */
+			ext_enable = 0x60;	/* r30[6]=1 ext enable; r30[5]:1 ext at lna max-1 */
+			loop_through = 0x00;	/* r5[7], lt on */
+			lt_att = 0x00;		/* r31[7], lt att enable */
+			flt_ext_widest = 0x00;	/* r15[7]: flt_ext_wide off */
+			polyfil_cur = 0x60;	/* r25[6:5]:min */
+		}
+	}
+
+	/* Initialize the shadow registers */
+	memcpy(priv->regs, r820t_init_array, sizeof(r820t_init_array));
+
+	/* Init Flag & Xtal_check Result */
+	if (priv->imr_done)
+		val = 1 | priv->xtal_cap_sel << 1;
+	else
+		val = 0;
+	rc = r820t_write_reg_mask(priv, 0x0c, val, 0x0f);
+	if (rc < 0)
+		return rc;
+
+	/* version */
+	rc = r820t_write_reg_mask(priv, 0x13, VER_NUM, 0x3f);
+	if (rc < 0)
+		return rc;
+
+	/* for LT Gain test */
+	if (type != V4L2_TUNER_ANALOG_TV) {
+		rc = r820t_write_reg_mask(priv, 0x1d, 0x00, 0x38);
+		if (rc < 0)
+			return rc;
+		usleep_range(1000, 2000);
+	}
+	priv->int_freq = if_khz * 1000;
+
+	/* Check if standard changed. If so, filter calibration is needed */
+	if (type != priv->type)
+		need_calibration = true;
+	else if ((type == V4L2_TUNER_ANALOG_TV) && (std != priv->std))
+		need_calibration = true;
+	else if ((type == V4L2_TUNER_DIGITAL_TV) &&
+		 ((delsys != priv->delsys) || bw != priv->bw))
+		need_calibration = true;
+	else
+		need_calibration = false;
+
+	if (need_calibration) {
+		tuner_dbg("calibrating the tuner\n");
+		for (i = 0; i < 2; i++) {
+			/* Set filt_cap */
+			rc = r820t_write_reg_mask(priv, 0x0b, hp_cor, 0x60);
+			if (rc < 0)
+				return rc;
+
+			/* set cali clk =on */
+			rc = r820t_write_reg_mask(priv, 0x0f, 0x04, 0x04);
+			if (rc < 0)
+				return rc;
+
+			/* X'tal cap 0pF for PLL */
+			rc = r820t_write_reg_mask(priv, 0x10, 0x00, 0x03);
+			if (rc < 0)
+				return rc;
+
+			rc = r820t_set_pll(priv, type, filt_cal_lo * 1000);
+			if (rc < 0 || !priv->has_lock)
+				return rc;
+
+			/* Start Trigger */
+			rc = r820t_write_reg_mask(priv, 0x0b, 0x10, 0x10);
+			if (rc < 0)
+				return rc;
+
+			usleep_range(1000, 2000);
+
+			/* Stop Trigger */
+			rc = r820t_write_reg_mask(priv, 0x0b, 0x00, 0x10);
+			if (rc < 0)
+				return rc;
+
+			/* set cali clk =off */
+			rc = r820t_write_reg_mask(priv, 0x0f, 0x00, 0x04);
+			if (rc < 0)
+				return rc;
+
+			/* Check if calibration worked */
+			rc = r820t_read(priv, 0x00, data, sizeof(data));
+			if (rc < 0)
+				return rc;
+
+			priv->fil_cal_code = data[4] & 0x0f;
+			if (priv->fil_cal_code && priv->fil_cal_code != 0x0f)
+				break;
+		}
+		/* narrowest */
+		if (priv->fil_cal_code == 0x0f)
+			priv->fil_cal_code = 0;
+	}
+
+	rc = r820t_write_reg_mask(priv, 0x0a,
+				  filt_q | priv->fil_cal_code, 0x1f);
+	if (rc < 0)
+		return rc;
+
+	/* Set BW, Filter_gain, & HP corner */
+	rc = r820t_write_reg_mask(priv, 0x0b, hp_cor, 0xef);
+	if (rc < 0)
+		return rc;
+
+
+	/* Set Img_R */
+	rc = r820t_write_reg_mask(priv, 0x07, img_r, 0x80);
+	if (rc < 0)
+		return rc;
+
+	/* Set filt_3dB, V6MHz */
+	rc = r820t_write_reg_mask(priv, 0x06, filt_gain, 0x30);
+	if (rc < 0)
+		return rc;
+
+	/* channel filter extension */
+	rc = r820t_write_reg_mask(priv, 0x1e, ext_enable, 0x60);
+	if (rc < 0)
+		return rc;
+
+	/* Loop through */
+	rc = r820t_write_reg_mask(priv, 0x05, loop_through, 0x80);
+	if (rc < 0)
+		return rc;
+
+	/* Loop through attenuation */
+	rc = r820t_write_reg_mask(priv, 0x1f, lt_att, 0x80);
+	if (rc < 0)
+		return rc;
+
+	/* filter extension widest */
+	rc = r820t_write_reg_mask(priv, 0x0f, flt_ext_widest, 0x80);
+	if (rc < 0)
+		return rc;
+
+	/* RF poly filter current */
+	rc = r820t_write_reg_mask(priv, 0x19, polyfil_cur, 0x60);
+	if (rc < 0)
+		return rc;
+
+	/* Store current standard. If it changes, re-calibrate the tuner */
+	priv->delsys = delsys;
+	priv->type = type;
+	priv->std = std;
+	priv->bw = bw;
+
+	return 0;
+}
+
+static int r820t_read_gain(struct r820t_priv *priv)
+{
+	u8 data[4];
+	int rc;
+
+	rc = r820t_read(priv, 0x00, data, sizeof(data));
+	if (rc < 0)
+		return rc;
+
+	return ((data[3] & 0x0f) << 1) + ((data[3] & 0xf0) >> 4);
+}
+
+#if 0
+/* FIXME: This routine requires more testing */
+static int r820t_set_gain_mode(struct r820t_priv *priv,
+			       bool set_manual_gain,
+			       int gain)
+{
+	int rc;
+
+	if (set_manual_gain) {
+		int i, total_gain = 0;
+		uint8_t mix_index = 0, lna_index = 0;
+		u8 data[4];
+
+		/* LNA auto off */
+		rc = r820t_write_reg_mask(priv, 0x05, 0x10, 0x10);
+		if (rc < 0)
+			return rc;
+
+		 /* Mixer auto off */
+		rc = r820t_write_reg_mask(priv, 0x07, 0, 0x10);
+		if (rc < 0)
+			return rc;
+
+		rc = r820t_read(priv, 0x00, data, sizeof(data));
+		if (rc < 0)
+			return rc;
+
+		/* set fixed VGA gain for now (16.3 dB) */
+		rc = r820t_write_reg_mask(priv, 0x0c, 0x08, 0x9f);
+		if (rc < 0)
+			return rc;
+
+		for (i = 0; i < 15; i++) {
+			if (total_gain >= gain)
+				break;
+
+			total_gain += r820t_lna_gain_steps[++lna_index];
+
+			if (total_gain >= gain)
+				break;
+
+			total_gain += r820t_mixer_gain_steps[++mix_index];
+		}
+
+		/* set LNA gain */
+		rc = r820t_write_reg_mask(priv, 0x05, lna_index, 0x0f);
+		if (rc < 0)
+			return rc;
+
+		/* set Mixer gain */
+		rc = r820t_write_reg_mask(priv, 0x07, mix_index, 0x0f);
+		if (rc < 0)
+			return rc;
+	} else {
+		/* LNA */
+		rc = r820t_write_reg_mask(priv, 0x05, 0, 0x10);
+		if (rc < 0)
+			return rc;
+
+		/* Mixer */
+		rc = r820t_write_reg_mask(priv, 0x07, 0x10, 0x10);
+		if (rc < 0)
+			return rc;
+
+		/* set fixed VGA gain for now (26.5 dB) */
+		rc = r820t_write_reg_mask(priv, 0x0c, 0x0b, 0x9f);
+		if (rc < 0)
+			return rc;
+	}
+
+	return 0;
+}
+#endif
+
+static int generic_set_freq(struct dvb_frontend *fe,
+			    u32 freq /* in HZ */,
+			    unsigned bw,
+			    enum v4l2_tuner_type type,
+			    v4l2_std_id std, u32 delsys)
+{
+	struct r820t_priv		*priv = fe->tuner_priv;
+	int				rc = -EINVAL;
+	u32				lo_freq;
+
+	tuner_dbg("should set frequency to %d kHz, bw %d MHz\n",
+		  freq / 1000, bw);
+
+	rc = r820t_set_tv_standard(priv, bw, type, std, delsys);
+	if (rc < 0)
+		goto err;
+
+	if ((type == V4L2_TUNER_ANALOG_TV) && (std == V4L2_STD_SECAM_LC))
+		lo_freq = freq - priv->int_freq;
+	 else
+		lo_freq = freq + priv->int_freq;
+
+	rc = r820t_set_mux(priv, lo_freq);
+	if (rc < 0)
+		goto err;
+
+	rc = r820t_set_pll(priv, type, lo_freq);
+	if (rc < 0 || !priv->has_lock)
+		goto err;
+
+	rc = r820t_sysfreq_sel(priv, freq, type, std, delsys);
+	if (rc < 0)
+		goto err;
+
+	tuner_dbg("%s: PLL locked on frequency %d Hz, gain=%d\n",
+		  __func__, freq, r820t_read_gain(priv));
+
+err:
+
+	if (rc < 0)
+		tuner_dbg("%s: failed=%d\n", __func__, rc);
+	return rc;
+}
+
+/*
+ * r820t standby logic
+ */
+
+static int r820t_standby(struct r820t_priv *priv)
+{
+	int rc;
+
+	/* If device was not initialized yet, don't need to standby */
+	if (!priv->init_done)
+		return 0;
+
+	rc = r820t_write_reg(priv, 0x06, 0xb1);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg(priv, 0x05, 0x03);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg(priv, 0x07, 0x3a);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg(priv, 0x08, 0x40);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg(priv, 0x09, 0xc0);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg(priv, 0x0a, 0x36);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg(priv, 0x0c, 0x35);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg(priv, 0x0f, 0x68);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg(priv, 0x11, 0x03);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg(priv, 0x17, 0xf4);
+	if (rc < 0)
+		return rc;
+	rc = r820t_write_reg(priv, 0x19, 0x0c);
+
+	/* Force initial calibration */
+	priv->type = -1;
+
+	return rc;
+}
+
+/*
+ * r820t device init logic
+ */
+
+static int r820t_xtal_check(struct r820t_priv *priv)
+{
+	int rc, i;
+	u8 data[3], val;
+
+	/* Initialize the shadow registers */
+	memcpy(priv->regs, r820t_init_array, sizeof(r820t_init_array));
+
+	/* cap 30pF & Drive Low */
+	rc = r820t_write_reg_mask(priv, 0x10, 0x0b, 0x0b);
+	if (rc < 0)
+		return rc;
+
+	/* set pll autotune = 128kHz */
+	rc = r820t_write_reg_mask(priv, 0x1a, 0x00, 0x0c);
+	if (rc < 0)
+		return rc;
+
+	/* set manual initial reg = 111111;  */
+	rc = r820t_write_reg_mask(priv, 0x13, 0x7f, 0x7f);
+	if (rc < 0)
+		return rc;
+
+	/* set auto */
+	rc = r820t_write_reg_mask(priv, 0x13, 0x00, 0x40);
+	if (rc < 0)
+		return rc;
+
+	/* Try several xtal capacitor alternatives */
+	for (i = 0; i < ARRAY_SIZE(r820t_xtal_capacitor); i++) {
+		rc = r820t_write_reg_mask(priv, 0x10,
+					  r820t_xtal_capacitor[i][0], 0x1b);
+		if (rc < 0)
+			return rc;
+
+		usleep_range(5000, 6000);
+
+		rc = r820t_read(priv, 0x00, data, sizeof(data));
+		if (rc < 0)
+			return rc;
+		if ((!data[2]) & 0x40)
+			continue;
+
+		val = data[2] & 0x3f;
+
+		if (priv->cfg->xtal == 16000000 && (val > 29 || val < 23))
+			break;
+
+		if (val != 0x3f)
+			break;
+	}
+
+	if (i == ARRAY_SIZE(r820t_xtal_capacitor))
+		return -EINVAL;
+
+	return r820t_xtal_capacitor[i][1];
+}
+
+static int r820t_imr_prepare(struct r820t_priv *priv)
+{
+	int rc;
+
+	/* Initialize the shadow registers */
+	memcpy(priv->regs, r820t_init_array, sizeof(r820t_init_array));
+
+	/* lna off (air-in off) */
+	rc = r820t_write_reg_mask(priv, 0x05, 0x20, 0x20);
+	if (rc < 0)
+		return rc;
+
+	/* mixer gain mode = manual */
+	rc = r820t_write_reg_mask(priv, 0x07, 0, 0x10);
+	if (rc < 0)
+		return rc;
+
+	/* filter corner = lowest */
+	rc = r820t_write_reg_mask(priv, 0x0a, 0x0f, 0x0f);
+	if (rc < 0)
+		return rc;
+
+	/* filter bw=+2cap, hp=5M */
+	rc = r820t_write_reg_mask(priv, 0x0b, 0x60, 0x6f);
+	if (rc < 0)
+		return rc;
+
+	/* adc=on, vga code mode, gain = 26.5dB   */
+	rc = r820t_write_reg_mask(priv, 0x0c, 0x0b, 0x9f);
+	if (rc < 0)
+		return rc;
+
+	/* ring clk = on */
+	rc = r820t_write_reg_mask(priv, 0x0f, 0, 0x08);
+	if (rc < 0)
+		return rc;
+
+	/* ring power = on */
+	rc = r820t_write_reg_mask(priv, 0x18, 0x10, 0x10);
+	if (rc < 0)
+		return rc;
+
+	/* from ring = ring pll in */
+	rc = r820t_write_reg_mask(priv, 0x1c, 0x02, 0x02);
+	if (rc < 0)
+		return rc;
+
+	/* sw_pdect = det3 */
+	rc = r820t_write_reg_mask(priv, 0x1e, 0x80, 0x80);
+	if (rc < 0)
+		return rc;
+
+	/* Set filt_3dB */
+	rc = r820t_write_reg_mask(priv, 0x06, 0x20, 0x20);
+
+	return rc;
+}
+
+static int r820t_multi_read(struct r820t_priv *priv)
+{
+	int rc, i;
+	u8 data[2], min = 0, max = 255, sum = 0;
+
+	usleep_range(5000, 6000);
+
+	for (i = 0; i < 6; i++) {
+		rc = r820t_read(priv, 0x00, data, sizeof(data));
+		if (rc < 0)
+			return rc;
+
+		sum += data[1];
+
+		if (data[1] < min)
+			min = data[1];
+
+		if (data[1] > max)
+			max = data[1];
+	}
+	rc = sum - max - min;
+
+	return rc;
+}
+
+static int r820t_imr_cross(struct r820t_priv *priv,
+			   struct r820t_sect_type iq_point[3],
+			   u8 *x_direct)
+{
+	struct r820t_sect_type cross[5]; /* (0,0)(0,Q-1)(0,I-1)(Q-1,0)(I-1,0) */
+	struct r820t_sect_type tmp;
+	int i, rc;
+	u8 reg08, reg09;
+
+	reg08 = r820t_read_cache_reg(priv, 8) & 0xc0;
+	reg09 = r820t_read_cache_reg(priv, 9) & 0xc0;
+
+	tmp.gain_x = 0;
+	tmp.phase_y = 0;
+	tmp.value = 255;
+
+	for (i = 0; i < 5; i++) {
+		switch (i) {
+		case 0:
+			cross[i].gain_x  = reg08;
+			cross[i].phase_y = reg09;
+			break;
+		case 1:
+			cross[i].gain_x  = reg08;		/* 0 */
+			cross[i].phase_y = reg09 + 1;		/* Q-1 */
+			break;
+		case 2:
+			cross[i].gain_x  = reg08;		/* 0 */
+			cross[i].phase_y = (reg09 | 0x20) + 1;	/* I-1 */
+			break;
+		case 3:
+			cross[i].gain_x  = reg08 + 1;		/* Q-1 */
+			cross[i].phase_y = reg09;
+			break;
+		default:
+			cross[i].gain_x  = (reg08 | 0x20) + 1;	/* I-1 */
+			cross[i].phase_y = reg09;
+		}
+
+		rc = r820t_write_reg(priv, 0x08, cross[i].gain_x);
+		if (rc < 0)
+			return rc;
+
+		rc = r820t_write_reg(priv, 0x09, cross[i].phase_y);
+		if (rc < 0)
+			return rc;
+
+		rc = r820t_multi_read(priv);
+		if (rc < 0)
+			return rc;
+
+		cross[i].value = rc;
+
+		if (cross[i].value < tmp.value)
+			memcpy(&tmp, &cross[i], sizeof(tmp));
+	}
+
+	if ((tmp.phase_y & 0x1f) == 1) {	/* y-direction */
+		*x_direct = 0;
+
+		iq_point[0] = cross[0];
+		iq_point[1] = cross[1];
+		iq_point[2] = cross[2];
+	} else {				/* (0,0) or x-direction */
+		*x_direct = 1;
+
+		iq_point[0] = cross[0];
+		iq_point[1] = cross[3];
+		iq_point[2] = cross[4];
+	}
+	return 0;
+}
+
+static void r820t_compre_cor(struct r820t_sect_type iq[3])
+{
+	int i;
+
+	for (i = 3; i > 0; i--) {
+		if (iq[0].value > iq[i - 1].value)
+			swap(iq[0], iq[i - 1]);
+	}
+}
+
+static int r820t_compre_step(struct r820t_priv *priv,
+			     struct r820t_sect_type iq[3], u8 reg)
+{
+	int rc;
+	struct r820t_sect_type tmp;
+
+	/*
+	 * Purpose: if (Gain<9 or Phase<9), Gain+1 or Phase+1 and compare
+	 * with min value:
+	 *  new < min => update to min and continue
+	 *  new > min => Exit
+	 */
+
+	/* min value already saved in iq[0] */
+	tmp.phase_y = iq[0].phase_y;
+	tmp.gain_x  = iq[0].gain_x;
+
+	while (((tmp.gain_x & 0x1f) < IMR_TRIAL) &&
+	      ((tmp.phase_y & 0x1f) < IMR_TRIAL)) {
+		if (reg == 0x08)
+			tmp.gain_x++;
+		else
+			tmp.phase_y++;
+
+		rc = r820t_write_reg(priv, 0x08, tmp.gain_x);
+		if (rc < 0)
+			return rc;
+
+		rc = r820t_write_reg(priv, 0x09, tmp.phase_y);
+		if (rc < 0)
+			return rc;
+
+		rc = r820t_multi_read(priv);
+		if (rc < 0)
+			return rc;
+		tmp.value = rc;
+
+		if (tmp.value <= iq[0].value) {
+			iq[0].gain_x  = tmp.gain_x;
+			iq[0].phase_y = tmp.phase_y;
+			iq[0].value   = tmp.value;
+		} else {
+			return 0;
+		}
+
+	}
+
+	return 0;
+}
+
+static int r820t_iq_tree(struct r820t_priv *priv,
+			 struct r820t_sect_type iq[3],
+			 u8 fix_val, u8 var_val, u8 fix_reg)
+{
+	int rc, i;
+	u8 tmp, var_reg;
+
+	/*
+	 * record IMC results by input gain/phase location then adjust
+	 * gain or phase positive 1 step and negtive 1 step,
+	 * both record results
+	 */
+
+	if (fix_reg == 0x08)
+		var_reg = 0x09;
+	else
+		var_reg = 0x08;
+
+	for (i = 0; i < 3; i++) {
+		rc = r820t_write_reg(priv, fix_reg, fix_val);
+		if (rc < 0)
+			return rc;
+
+		rc = r820t_write_reg(priv, var_reg, var_val);
+		if (rc < 0)
+			return rc;
+
+		rc = r820t_multi_read(priv);
+		if (rc < 0)
+			return rc;
+		iq[i].value = rc;
+
+		if (fix_reg == 0x08) {
+			iq[i].gain_x  = fix_val;
+			iq[i].phase_y = var_val;
+		} else {
+			iq[i].phase_y = fix_val;
+			iq[i].gain_x  = var_val;
+		}
+
+		if (i == 0) {  /* try right-side point */
+			var_val++;
+		} else if (i == 1) { /* try left-side point */
+			 /* if absolute location is 1, change I/Q direction */
+			if ((var_val & 0x1f) < 0x02) {
+				tmp = 2 - (var_val & 0x1f);
+
+				/* b[5]:I/Q selection. 0:Q-path, 1:I-path */
+				if (var_val & 0x20) {
+					var_val &= 0xc0;
+					var_val |= tmp;
+				} else {
+					var_val |= 0x20 | tmp;
+				}
+			} else {
+				var_val -= 2;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int r820t_section(struct r820t_priv *priv,
+			 struct r820t_sect_type *iq_point)
+{
+	int rc;
+	struct r820t_sect_type compare_iq[3], compare_bet[3];
+
+	/* Try X-1 column and save min result to compare_bet[0] */
+	if (!(iq_point->gain_x & 0x1f))
+		compare_iq[0].gain_x = ((iq_point->gain_x) & 0xdf) + 1;  /* Q-path, Gain=1 */
+	else
+		compare_iq[0].gain_x  = iq_point->gain_x - 1;  /* left point */
+	compare_iq[0].phase_y = iq_point->phase_y;
+
+	/* y-direction */
+	rc = r820t_iq_tree(priv, compare_iq,  compare_iq[0].gain_x,
+			compare_iq[0].phase_y, 0x08);
+	if (rc < 0)
+		return rc;
+
+	r820t_compre_cor(compare_iq);
+
+	compare_bet[0] = compare_iq[0];
+
+	/* Try X column and save min result to compare_bet[1] */
+	compare_iq[0].gain_x  = iq_point->gain_x;
+	compare_iq[0].phase_y = iq_point->phase_y;
+
+	rc = r820t_iq_tree(priv, compare_iq,  compare_iq[0].gain_x,
+			   compare_iq[0].phase_y, 0x08);
+	if (rc < 0)
+		return rc;
+
+	r820t_compre_cor(compare_iq);
+
+	compare_bet[1] = compare_iq[0];
+
+	/* Try X+1 column and save min result to compare_bet[2] */
+	if ((iq_point->gain_x & 0x1f) == 0x00)
+		compare_iq[0].gain_x = ((iq_point->gain_x) | 0x20) + 1;  /* I-path, Gain=1 */
+	else
+		compare_iq[0].gain_x = iq_point->gain_x + 1;
+	compare_iq[0].phase_y = iq_point->phase_y;
+
+	rc = r820t_iq_tree(priv, compare_iq,  compare_iq[0].gain_x,
+			   compare_iq[0].phase_y, 0x08);
+	if (rc < 0)
+		return rc;
+
+	r820t_compre_cor(compare_iq);
+
+	compare_bet[2] = compare_iq[0];
+
+	r820t_compre_cor(compare_bet);
+
+	*iq_point = compare_bet[0];
+
+	return 0;
+}
+
+static int r820t_vga_adjust(struct r820t_priv *priv)
+{
+	int rc;
+	u8 vga_count;
+
+	/* increase vga power to let image significant */
+	for (vga_count = 12; vga_count < 16; vga_count++) {
+		rc = r820t_write_reg_mask(priv, 0x0c, vga_count, 0x0f);
+		if (rc < 0)
+			return rc;
+
+		usleep_range(10000, 11000);
+
+		rc = r820t_multi_read(priv);
+		if (rc < 0)
+			return rc;
+
+		if (rc > 40 * 4)
+			break;
+	}
+
+	return 0;
+}
+
+static int r820t_iq(struct r820t_priv *priv, struct r820t_sect_type *iq_pont)
+{
+	struct r820t_sect_type compare_iq[3];
+	int rc;
+	u8 x_direction = 0;  /* 1:x, 0:y */
+	u8 dir_reg, other_reg;
+
+	r820t_vga_adjust(priv);
+
+	rc = r820t_imr_cross(priv, compare_iq, &x_direction);
+	if (rc < 0)
+		return rc;
+
+	if (x_direction == 1) {
+		dir_reg   = 0x08;
+		other_reg = 0x09;
+	} else {
+		dir_reg   = 0x09;
+		other_reg = 0x08;
+	}
+
+	/* compare and find min of 3 points. determine i/q direction */
+	r820t_compre_cor(compare_iq);
+
+	/* increase step to find min value of this direction */
+	rc = r820t_compre_step(priv, compare_iq, dir_reg);
+	if (rc < 0)
+		return rc;
+
+	/* the other direction */
+	rc = r820t_iq_tree(priv, compare_iq,  compare_iq[0].gain_x,
+				compare_iq[0].phase_y, dir_reg);
+	if (rc < 0)
+		return rc;
+
+	/* compare and find min of 3 points. determine i/q direction */
+	r820t_compre_cor(compare_iq);
+
+	/* increase step to find min value on this direction */
+	rc = r820t_compre_step(priv, compare_iq, other_reg);
+	if (rc < 0)
+		return rc;
+
+	/* check 3 points again */
+	rc = r820t_iq_tree(priv, compare_iq,  compare_iq[0].gain_x,
+				compare_iq[0].phase_y, other_reg);
+	if (rc < 0)
+		return rc;
+
+	r820t_compre_cor(compare_iq);
+
+	/* section-9 check */
+	rc = r820t_section(priv, compare_iq);
+
+	*iq_pont = compare_iq[0];
+
+	/* reset gain/phase control setting */
+	rc = r820t_write_reg_mask(priv, 0x08, 0, 0x3f);
+	if (rc < 0)
+		return rc;
+
+	rc = r820t_write_reg_mask(priv, 0x09, 0, 0x3f);
+
+	return rc;
+}
+
+static int r820t_f_imr(struct r820t_priv *priv, struct r820t_sect_type *iq_pont)
+{
+	int rc;
+
+	r820t_vga_adjust(priv);
+
+	/*
+	 * search surrounding points from previous point
+	 * try (x-1), (x), (x+1) columns, and find min IMR result point
+	 */
+	rc = r820t_section(priv, iq_pont);
+	if (rc < 0)
+		return rc;
+
+	return 0;
+}
+
+static int r820t_imr(struct r820t_priv *priv, unsigned imr_mem, bool im_flag)
+{
+	struct r820t_sect_type imr_point;
+	int rc;
+	u32 ring_vco, ring_freq, ring_ref;
+	u8 n_ring, n;
+	int reg18, reg19, reg1f;
+
+	if (priv->cfg->xtal > 24000000)
+		ring_ref = priv->cfg->xtal / 2;
+	else
+		ring_ref = priv->cfg->xtal;
+
+	for (n = 0; n < 16; n++) {
+		if ((16 + n) * 8 * ring_ref >= 3100000) {
+			n_ring = n;
+			break;
+		}
+
+		/* n_ring not found */
+		if (n == 15)
+			n_ring = n;
+	}
+
+	reg18 = r820t_read_cache_reg(priv, 0x18);
+	reg19 = r820t_read_cache_reg(priv, 0x19);
+	reg1f = r820t_read_cache_reg(priv, 0x1f);
+
+	reg18 &= 0xf0;      /* set ring[3:0] */
+	reg18 |= n_ring;
+
+	ring_vco = (16 + n_ring) * 8 * ring_ref;
+
+	reg18 &= 0xdf;   /* clear ring_se23 */
+	reg19 &= 0xfc;   /* clear ring_seldiv */
+	reg1f &= 0xfc;   /* clear ring_att */
+
+	switch (imr_mem) {
+	case 0:
+		ring_freq = ring_vco / 48;
+		reg18 |= 0x20;  /* ring_se23 = 1 */
+		reg19 |= 0x03;  /* ring_seldiv = 3 */
+		reg1f |= 0x02;  /* ring_att 10 */
+		break;
+	case 1:
+		ring_freq = ring_vco / 16;
+		reg18 |= 0x00;  /* ring_se23 = 0 */
+		reg19 |= 0x02;  /* ring_seldiv = 2 */
+		reg1f |= 0x00;  /* pw_ring 00 */
+		break;
+	case 2:
+		ring_freq = ring_vco / 8;
+		reg18 |= 0x00;  /* ring_se23 = 0 */
+		reg19 |= 0x01;  /* ring_seldiv = 1 */
+		reg1f |= 0x03;  /* pw_ring 11 */
+		break;
+	case 3:
+		ring_freq = ring_vco / 6;
+		reg18 |= 0x20;  /* ring_se23 = 1 */
+		reg19 |= 0x00;  /* ring_seldiv = 0 */
+		reg1f |= 0x03;  /* pw_ring 11 */
+		break;
+	case 4:
+		ring_freq = ring_vco / 4;
+		reg18 |= 0x00;  /* ring_se23 = 0 */
+		reg19 |= 0x00;  /* ring_seldiv = 0 */
+		reg1f |= 0x01;  /* pw_ring 01 */
+		break;
+	default:
+		ring_freq = ring_vco / 4;
+		reg18 |= 0x00;  /* ring_se23 = 0 */
+		reg19 |= 0x00;  /* ring_seldiv = 0 */
+		reg1f |= 0x01;  /* pw_ring 01 */
+		break;
+	}
+
+
+	/* write pw_ring, n_ring, ringdiv2 registers */
+
+	/* n_ring, ring_se23 */
+	rc = r820t_write_reg(priv, 0x18, reg18);
+	if (rc < 0)
+		return rc;
+
+	/* ring_sediv */
+	rc = r820t_write_reg(priv, 0x19, reg19);
+	if (rc < 0)
+		return rc;
+
+	/* pw_ring */
+	rc = r820t_write_reg(priv, 0x1f, reg1f);
+	if (rc < 0)
+		return rc;
+
+	/* mux input freq ~ rf_in freq */
+	rc = r820t_set_mux(priv, (ring_freq - 5300) * 1000);
+	if (rc < 0)
+		return rc;
+
+	rc = r820t_set_pll(priv, V4L2_TUNER_DIGITAL_TV,
+			   (ring_freq - 5300) * 1000);
+	if (!priv->has_lock)
+		rc = -EINVAL;
+	if (rc < 0)
+		return rc;
+
+	if (im_flag) {
+		rc = r820t_iq(priv, &imr_point);
+	} else {
+		imr_point.gain_x  = priv->imr_data[3].gain_x;
+		imr_point.phase_y = priv->imr_data[3].phase_y;
+		imr_point.value   = priv->imr_data[3].value;
+
+		rc = r820t_f_imr(priv, &imr_point);
+	}
+	if (rc < 0)
+		return rc;
+
+	/* save IMR value */
+	switch (imr_mem) {
+	case 0:
+		priv->imr_data[0].gain_x  = imr_point.gain_x;
+		priv->imr_data[0].phase_y = imr_point.phase_y;
+		priv->imr_data[0].value   = imr_point.value;
+		break;
+	case 1:
+		priv->imr_data[1].gain_x  = imr_point.gain_x;
+		priv->imr_data[1].phase_y = imr_point.phase_y;
+		priv->imr_data[1].value   = imr_point.value;
+		break;
+	case 2:
+		priv->imr_data[2].gain_x  = imr_point.gain_x;
+		priv->imr_data[2].phase_y = imr_point.phase_y;
+		priv->imr_data[2].value   = imr_point.value;
+		break;
+	case 3:
+		priv->imr_data[3].gain_x  = imr_point.gain_x;
+		priv->imr_data[3].phase_y = imr_point.phase_y;
+		priv->imr_data[3].value   = imr_point.value;
+		break;
+	case 4:
+		priv->imr_data[4].gain_x  = imr_point.gain_x;
+		priv->imr_data[4].phase_y = imr_point.phase_y;
+		priv->imr_data[4].value   = imr_point.value;
+		break;
+	default:
+		priv->imr_data[4].gain_x  = imr_point.gain_x;
+		priv->imr_data[4].phase_y = imr_point.phase_y;
+		priv->imr_data[4].value   = imr_point.value;
+		break;
+	}
+
+	return 0;
+}
+
+static int r820t_imr_callibrate(struct r820t_priv *priv)
+{
+	int rc, i;
+	int xtal_cap = 0;
+
+	if (priv->init_done)
+		return 0;
+
+	/* Detect Xtal capacitance */
+	if ((priv->cfg->rafael_chip == CHIP_R820T) ||
+	    (priv->cfg->rafael_chip == CHIP_R828S) ||
+	    (priv->cfg->rafael_chip == CHIP_R820C)) {
+		priv->xtal_cap_sel = XTAL_HIGH_CAP_0P;
+	} else {
+		/* Initialize registers */
+		rc = r820t_write(priv, 0x05,
+				r820t_init_array, sizeof(r820t_init_array));
+		if (rc < 0)
+			return rc;
+		for (i = 0; i < 3; i++) {
+			rc = r820t_xtal_check(priv);
+			if (rc < 0)
+				return rc;
+			if (!i || rc > xtal_cap)
+				xtal_cap = rc;
+		}
+		priv->xtal_cap_sel = xtal_cap;
+	}
+
+	/*
+	 * Disables IMR callibration. That emulates the same behaviour
+	 * as what is done by rtl-sdr userspace library. Useful for testing
+	 */
+	if (no_imr_cal) {
+		priv->init_done = true;
+
+		return 0;
+	}
+
+	/* Initialize registers */
+	rc = r820t_write(priv, 0x05,
+			 r820t_init_array, sizeof(r820t_init_array));
+	if (rc < 0)
+		return rc;
+
+	rc = r820t_imr_prepare(priv);
+	if (rc < 0)
+		return rc;
+
+	rc = r820t_imr(priv, 3, true);
+	if (rc < 0)
+		return rc;
+	rc = r820t_imr(priv, 1, false);
+	if (rc < 0)
+		return rc;
+	rc = r820t_imr(priv, 0, false);
+	if (rc < 0)
+		return rc;
+	rc = r820t_imr(priv, 2, false);
+	if (rc < 0)
+		return rc;
+	rc = r820t_imr(priv, 4, false);
+	if (rc < 0)
+		return rc;
+
+	priv->init_done = true;
+	priv->imr_done = true;
+
+	return 0;
+}
+
+#if 0
+/* Not used, for now */
+static int r820t_gpio(struct r820t_priv *priv, bool enable)
+{
+	return r820t_write_reg_mask(priv, 0x0f, enable ? 1 : 0, 0x01);
+}
+#endif
+
+/*
+ *  r820t frontend operations and tuner attach code
+ *
+ * All driver locks and i2c control are only in this part of the code
+ */
+
+static int r820t_init(struct dvb_frontend *fe)
+{
+	struct r820t_priv *priv = fe->tuner_priv;
+	int rc;
+
+	tuner_dbg("%s:\n", __func__);
+
+	mutex_lock(&priv->lock);
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 1);
+
+	rc = r820t_imr_callibrate(priv);
+	if (rc < 0)
+		goto err;
+
+	/* Initialize registers */
+	rc = r820t_write(priv, 0x05,
+			 r820t_init_array, sizeof(r820t_init_array));
+
+err:
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 0);
+	mutex_unlock(&priv->lock);
+
+	if (rc < 0)
+		tuner_dbg("%s: failed=%d\n", __func__, rc);
+	return rc;
+}
+
+static int r820t_sleep(struct dvb_frontend *fe)
+{
+	struct r820t_priv *priv = fe->tuner_priv;
+	int rc;
+
+	tuner_dbg("%s:\n", __func__);
+
+	mutex_lock(&priv->lock);
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 1);
+
+	rc = r820t_standby(priv);
+
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 0);
+	mutex_unlock(&priv->lock);
+
+	tuner_dbg("%s: failed=%d\n", __func__, rc);
+	return rc;
+}
+
+static int r820t_set_analog_freq(struct dvb_frontend *fe,
+				 struct analog_parameters *p)
+{
+	struct r820t_priv *priv = fe->tuner_priv;
+	unsigned bw;
+	int rc;
+
+	tuner_dbg("%s called\n", __func__);
+
+	/* if std is not defined, choose one */
+	if (!p->std)
+		p->std = V4L2_STD_MN;
+
+	if ((p->std == V4L2_STD_PAL_M) || (p->std == V4L2_STD_NTSC))
+		bw = 6;
+	else
+		bw = 8;
+
+	mutex_lock(&priv->lock);
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 1);
+
+	rc = generic_set_freq(fe, 62500l * p->frequency, bw,
+			      V4L2_TUNER_ANALOG_TV, p->std, SYS_UNDEFINED);
+
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 0);
+	mutex_unlock(&priv->lock);
+
+	return rc;
+}
+
+static int r820t_set_params(struct dvb_frontend *fe)
+{
+	struct r820t_priv *priv = fe->tuner_priv;
+	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+	int rc;
+	unsigned bw;
+
+	tuner_dbg("%s: delivery_system=%d frequency=%d bandwidth_hz=%d\n",
+		__func__, c->delivery_system, c->frequency, c->bandwidth_hz);
+
+	mutex_lock(&priv->lock);
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 1);
+
+	bw = (c->bandwidth_hz + 500000) / 1000000;
+	if (!bw)
+		bw = 8;
+
+	rc = generic_set_freq(fe, c->frequency, bw,
+			      V4L2_TUNER_DIGITAL_TV, 0, c->delivery_system);
+
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 0);
+	mutex_unlock(&priv->lock);
+
+	if (rc)
+		tuner_dbg("%s: failed=%d\n", __func__, rc);
+	return rc;
+}
+
+static int r820t_signal(struct dvb_frontend *fe, u16 *strength)
+{
+	struct r820t_priv *priv = fe->tuner_priv;
+	int rc = 0;
+
+	mutex_lock(&priv->lock);
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 1);
+
+	if (priv->has_lock) {
+		rc = r820t_read_gain(priv);
+		if (rc < 0)
+			goto err;
+
+		/* A higher gain at LNA means a lower signal strength */
+		*strength = (45 - rc) << 4 | 0xff;
+		if (*strength == 0xff)
+			*strength = 0;
+	} else {
+		*strength = 0;
+	}
+
+err:
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 0);
+	mutex_unlock(&priv->lock);
+
+	tuner_dbg("%s: %s, gain=%d strength=%d\n",
+		  __func__,
+		  priv->has_lock ? "PLL locked" : "no signal",
+		  rc, *strength);
+
+	return 0;
+}
+
+static int r820t_get_if_frequency(struct dvb_frontend *fe, u32 *frequency)
+{
+	struct r820t_priv *priv = fe->tuner_priv;
+
+	tuner_dbg("%s:\n", __func__);
+
+	*frequency = priv->int_freq;
+
+	return 0;
+}
+
+static int r820t_release(struct dvb_frontend *fe)
+{
+	struct r820t_priv *priv = fe->tuner_priv;
+
+	tuner_dbg("%s:\n", __func__);
+
+	mutex_lock(&r820t_list_mutex);
+
+	if (priv)
+		hybrid_tuner_release_state(priv);
+
+	mutex_unlock(&r820t_list_mutex);
+
+	fe->tuner_priv = NULL;
+
+	kfree(fe->tuner_priv);
+
+	return 0;
+}
+
+static const struct dvb_tuner_ops r820t_tuner_ops = {
+	.info = {
+		.name           = "Rafael Micro R820T",
+		.frequency_min  =   42000000,
+		.frequency_max  = 1002000000,
+	},
+	.init = r820t_init,
+	.release = r820t_release,
+	.sleep = r820t_sleep,
+	.set_params = r820t_set_params,
+	.set_analog_params = r820t_set_analog_freq,
+	.get_if_frequency = r820t_get_if_frequency,
+	.get_rf_strength = r820t_signal,
+};
+
+struct dvb_frontend *r820t_attach(struct dvb_frontend *fe,
+				  struct i2c_adapter *i2c,
+				  const struct r820t_config *cfg)
+{
+	struct r820t_priv *priv;
+	int rc = -ENODEV;
+	u8 data[5];
+	int instance;
+
+	mutex_lock(&r820t_list_mutex);
+
+	instance = hybrid_tuner_request_state(struct r820t_priv, priv,
+					      hybrid_tuner_instance_list,
+					      i2c, cfg->i2c_addr,
+					      "r820t");
+	switch (instance) {
+	case 0:
+		/* memory allocation failure */
+		goto err_no_gate;
+		break;
+	case 1:
+		/* new tuner instance */
+		priv->cfg = cfg;
+
+		mutex_init(&priv->lock);
+
+		fe->tuner_priv = priv;
+		break;
+	case 2:
+		/* existing tuner instance */
+		fe->tuner_priv = priv;
+		break;
+	}
+
+	memcpy(&fe->ops.tuner_ops, &r820t_tuner_ops, sizeof(r820t_tuner_ops));
+
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 1);
+
+	/* check if the tuner is there */
+	rc = r820t_read(priv, 0x00, data, sizeof(data));
+	if (rc < 0)
+		goto err;
+
+	rc = r820t_sleep(fe);
+	if (rc < 0)
+		goto err;
+
+	tuner_info("Rafael Micro r820t successfully identified\n");
+
+	fe->tuner_priv = priv;
+	memcpy(&fe->ops.tuner_ops, &r820t_tuner_ops,
+			sizeof(struct dvb_tuner_ops));
+
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 0);
+
+	mutex_unlock(&r820t_list_mutex);
+
+	return fe;
+err:
+	if (fe->ops.i2c_gate_ctrl)
+		fe->ops.i2c_gate_ctrl(fe, 0);
+
+err_no_gate:
+	mutex_unlock(&r820t_list_mutex);
+
+	tuner_info("%s: failed=%d\n", __func__, rc);
+	r820t_release(fe);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(r820t_attach);
+
+MODULE_DESCRIPTION("Rafael Micro r820t silicon tuner driver");
+MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/media/tuners/r820t.h b/drivers/media/tuners/r820t.h
new file mode 100644
index 000000000000..4c0823b21693
--- /dev/null
+++ b/drivers/media/tuners/r820t.h
@@ -0,0 +1,58 @@
+/*
+ * Elonics R820T silicon tuner driver
+ *
+ * Copyright (C) 2012 Antti Palosaari <crope@iki.fi>
+ *
+ *    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.
+ */
+
+#ifndef R820T_H
+#define R820T_H
+
+#include <linux/kconfig.h>
+#include "dvb_frontend.h"
+
+enum r820t_chip {
+	CHIP_R820T,
+	CHIP_R620D,
+	CHIP_R828D,
+	CHIP_R828,
+	CHIP_R828S,
+	CHIP_R820C,
+};
+
+struct r820t_config {
+	u8 i2c_addr;		/* 0x34 */
+	u32 xtal;
+	enum r820t_chip rafael_chip;
+	unsigned max_i2c_msg_len;
+	bool use_diplexer;
+};
+
+#if IS_ENABLED(CONFIG_MEDIA_TUNER_R820T)
+struct dvb_frontend *r820t_attach(struct dvb_frontend *fe,
+				  struct i2c_adapter *i2c,
+				  const struct r820t_config *cfg);
+#else
+static inline struct dvb_frontend *r820t_attach(struct dvb_frontend *fe,
+						struct i2c_adapter *i2c,
+						const struct r820t_config *cfg)
+{
+	pr_warn("%s: driver disabled by Kconfig\n", __func__);
+	return NULL;
+}
+#endif
+
+#endif
diff --git a/drivers/media/usb/dvb-usb-v2/Kconfig b/drivers/media/usb/dvb-usb-v2/Kconfig
index 9aff03555464..a3c8ecf22078 100644
--- a/drivers/media/usb/dvb-usb-v2/Kconfig
+++ b/drivers/media/usb/dvb-usb-v2/Kconfig
@@ -143,6 +143,7 @@ config DVB_USB_RTL28XXU
 	select MEDIA_TUNER_FC0013 if MEDIA_SUBDRV_AUTOSELECT
 	select MEDIA_TUNER_E4000 if MEDIA_SUBDRV_AUTOSELECT
 	select MEDIA_TUNER_FC2580 if MEDIA_SUBDRV_AUTOSELECT
+	select MEDIA_TUNER_R820T if MEDIA_SUBDRV_AUTOSELECT
 	help
 	  Say Y here to support the Realtek RTL28xxU DVB USB receiver.
 
diff --git a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
index 3d128a5e4794..22015fe1a0f3 100644
--- a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
+++ b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
@@ -33,6 +33,7 @@
 #include "e4000.h"
 #include "fc2580.h"
 #include "tua9001.h"
+#include "r820t.h"
 
 DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr);
 
@@ -375,6 +376,7 @@ static int rtl2832u_read_config(struct dvb_usb_device *d)
 	struct rtl28xxu_req req_mxl5007t = {0xd9c0, CMD_I2C_RD, 1, buf};
 	struct rtl28xxu_req req_e4000 = {0x02c8, CMD_I2C_RD, 1, buf};
 	struct rtl28xxu_req req_tda18272 = {0x00c0, CMD_I2C_RD, 2, buf};
+	struct rtl28xxu_req req_r820t = {0x0034, CMD_I2C_RD, 5, buf};
 
 	dev_dbg(&d->udev->dev, "%s:\n", __func__);
 
@@ -479,6 +481,14 @@ static int rtl2832u_read_config(struct dvb_usb_device *d)
 		goto found;
 	}
 
+	/* check R820T by reading tuner stats at I2C addr 0x1a */
+	ret = rtl28xxu_ctrl_msg(d, &req_r820t);
+	if (ret == 0) {
+		priv->tuner = TUNER_RTL2832_R820T;
+		priv->tuner_name = "R820T";
+		goto found;
+	}
+
 found:
 	dev_dbg(&d->udev->dev, "%s: tuner=%s\n", __func__, priv->tuner_name);
 
@@ -589,6 +599,12 @@ static struct rtl2832_config rtl28xxu_rtl2832_e4000_config = {
 	.tuner = TUNER_RTL2832_E4000,
 };
 
+static struct rtl2832_config rtl28xxu_rtl2832_r820t_config = {
+	.i2c_addr = 0x10,
+	.xtal = 28800000,
+	.tuner = TUNER_RTL2832_R820T,
+};
+
 static int rtl2832u_fc0012_tuner_callback(struct dvb_usb_device *d,
 		int cmd, int arg)
 {
@@ -728,6 +744,9 @@ static int rtl2832u_frontend_attach(struct dvb_usb_adapter *adap)
 	case TUNER_RTL2832_E4000:
 		rtl2832_config = &rtl28xxu_rtl2832_e4000_config;
 		break;
+	case TUNER_RTL2832_R820T:
+		rtl2832_config = &rtl28xxu_rtl2832_r820t_config;
+		break;
 	default:
 		dev_err(&d->udev->dev, "%s: unknown tuner=%s\n",
 				KBUILD_MODNAME, priv->tuner_name);
@@ -840,6 +859,13 @@ static const struct fc0012_config rtl2832u_fc0012_config = {
 	.xtal_freq = FC_XTAL_28_8_MHZ,
 };
 
+static const struct r820t_config rtl2832u_r820t_config = {
+	.i2c_addr = 0x1a,
+	.xtal = 28800000,
+	.max_i2c_msg_len = 2,
+	.rafael_chip = CHIP_R820T,
+};
+
 static int rtl2832u_tuner_attach(struct dvb_usb_adapter *adap)
 {
 	int ret;
@@ -889,6 +915,14 @@ static int rtl2832u_tuner_attach(struct dvb_usb_adapter *adap)
 		fe = dvb_attach(tua9001_attach, adap->fe[0], &d->i2c_adap,
 				&rtl2832u_tua9001_config);
 		break;
+	case TUNER_RTL2832_R820T:
+		fe = dvb_attach(r820t_attach, adap->fe[0], &d->i2c_adap,
+				&rtl2832u_r820t_config);
+
+		/* Use tuner to get the signal strength */
+		adap->fe[0]->ops.read_signal_strength =
+				adap->fe[0]->ops.tuner_ops.get_rf_strength;
+		break;
 	default:
 		fe = NULL;
 		dev_err(&d->udev->dev, "%s: unknown tuner=%d\n", KBUILD_MODNAME,
diff --git a/drivers/media/usb/dvb-usb-v2/rtl28xxu.h b/drivers/media/usb/dvb-usb-v2/rtl28xxu.h
index 2f3af2d3b6ce..533a33127289 100644
--- a/drivers/media/usb/dvb-usb-v2/rtl28xxu.h
+++ b/drivers/media/usb/dvb-usb-v2/rtl28xxu.h
@@ -82,6 +82,7 @@ enum rtl28xxu_tuner {
 	TUNER_RTL2832_E4000,
 	TUNER_RTL2832_TDA18272,
 	TUNER_RTL2832_FC0013,
+	TUNER_RTL2832_R820T,
 };
 
 struct rtl28xxu_req {