Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 738 insertions, 0 deletions

diff --git a/drivers/media/dvb-frontends/ts2020.c b/drivers/media/dvb-frontends/ts2020.c
new file mode 100644
index 000000000..8775083f4
--- /dev/null
+++ b/drivers/media/dvb-frontends/ts2020.c
@@ -0,0 +1,738 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+    Montage Technology TS2020 - Silicon Tuner driver
+    Copyright (C) 2009-2012 Konstantin Dimitrov <kosio.dimitrov@gmail.com>
+
+    Copyright (C) 2009-2012 TurboSight.com
+
+ */
+
+#include <media/dvb_frontend.h>
+#include "ts2020.h"
+#include <linux/regmap.h>
+#include <linux/math64.h>
+
+#define TS2020_XTAL_FREQ   27000 /* in kHz */
+#define FREQ_OFFSET_LOW_SYM_RATE 3000
+
+struct ts2020_priv {
+	struct i2c_client *client;
+	struct mutex regmap_mutex;
+	struct regmap_config regmap_config;
+	struct regmap *regmap;
+	struct dvb_frontend *fe;
+	struct delayed_work stat_work;
+	int (*get_agc_pwm)(struct dvb_frontend *fe, u8 *_agc_pwm);
+	/* i2c details */
+	struct i2c_adapter *i2c;
+	int i2c_address;
+	bool loop_through:1;
+	u8 clk_out:2;
+	u8 clk_out_div:5;
+	bool dont_poll:1;
+	u32 frequency_div; /* LO output divider switch frequency */
+	u32 frequency_khz; /* actual used LO frequency */
+#define TS2020_M88TS2020 0
+#define TS2020_M88TS2022 1
+	u8 tuner;
+};
+
+struct ts2020_reg_val {
+	u8 reg;
+	u8 val;
+};
+
+static void ts2020_stat_work(struct work_struct *work);
+
+static void ts2020_release(struct dvb_frontend *fe)
+{
+	struct ts2020_priv *priv = fe->tuner_priv;
+	struct i2c_client *client = priv->client;
+
+	dev_dbg(&client->dev, "\n");
+
+	i2c_unregister_device(client);
+}
+
+static int ts2020_sleep(struct dvb_frontend *fe)
+{
+	struct ts2020_priv *priv = fe->tuner_priv;
+	int ret;
+	u8 u8tmp;
+
+	if (priv->tuner == TS2020_M88TS2020)
+		u8tmp = 0x0a; /* XXX: probably wrong */
+	else
+		u8tmp = 0x00;
+
+	ret = regmap_write(priv->regmap, u8tmp, 0x00);
+	if (ret < 0)
+		return ret;
+
+	/* stop statistics polling */
+	if (!priv->dont_poll)
+		cancel_delayed_work_sync(&priv->stat_work);
+	return 0;
+}
+
+static int ts2020_init(struct dvb_frontend *fe)
+{
+	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+	struct ts2020_priv *priv = fe->tuner_priv;
+	int i;
+	u8 u8tmp;
+
+	if (priv->tuner == TS2020_M88TS2020) {
+		regmap_write(priv->regmap, 0x42, 0x73);
+		regmap_write(priv->regmap, 0x05, priv->clk_out_div);
+		regmap_write(priv->regmap, 0x20, 0x27);
+		regmap_write(priv->regmap, 0x07, 0x02);
+		regmap_write(priv->regmap, 0x11, 0xff);
+		regmap_write(priv->regmap, 0x60, 0xf9);
+		regmap_write(priv->regmap, 0x08, 0x01);
+		regmap_write(priv->regmap, 0x00, 0x41);
+	} else {
+		static const struct ts2020_reg_val reg_vals[] = {
+			{0x7d, 0x9d},
+			{0x7c, 0x9a},
+			{0x7a, 0x76},
+			{0x3b, 0x01},
+			{0x63, 0x88},
+			{0x61, 0x85},
+			{0x22, 0x30},
+			{0x30, 0x40},
+			{0x20, 0x23},
+			{0x24, 0x02},
+			{0x12, 0xa0},
+		};
+
+		regmap_write(priv->regmap, 0x00, 0x01);
+		regmap_write(priv->regmap, 0x00, 0x03);
+
+		switch (priv->clk_out) {
+		case TS2020_CLK_OUT_DISABLED:
+			u8tmp = 0x60;
+			break;
+		case TS2020_CLK_OUT_ENABLED:
+			u8tmp = 0x70;
+			regmap_write(priv->regmap, 0x05, priv->clk_out_div);
+			break;
+		case TS2020_CLK_OUT_ENABLED_XTALOUT:
+			u8tmp = 0x6c;
+			break;
+		default:
+			u8tmp = 0x60;
+			break;
+		}
+
+		regmap_write(priv->regmap, 0x42, u8tmp);
+
+		if (priv->loop_through)
+			u8tmp = 0xec;
+		else
+			u8tmp = 0x6c;
+
+		regmap_write(priv->regmap, 0x62, u8tmp);
+
+		for (i = 0; i < ARRAY_SIZE(reg_vals); i++)
+			regmap_write(priv->regmap, reg_vals[i].reg,
+				     reg_vals[i].val);
+	}
+
+	/* Initialise v5 stats here */
+	c->strength.len = 1;
+	c->strength.stat[0].scale = FE_SCALE_DECIBEL;
+	c->strength.stat[0].uvalue = 0;
+
+	/* Start statistics polling by invoking the work function */
+	ts2020_stat_work(&priv->stat_work.work);
+	return 0;
+}
+
+static int ts2020_tuner_gate_ctrl(struct dvb_frontend *fe, u8 offset)
+{
+	struct ts2020_priv *priv = fe->tuner_priv;
+	int ret;
+	ret = regmap_write(priv->regmap, 0x51, 0x1f - offset);
+	ret |= regmap_write(priv->regmap, 0x51, 0x1f);
+	ret |= regmap_write(priv->regmap, 0x50, offset);
+	ret |= regmap_write(priv->regmap, 0x50, 0x00);
+	msleep(20);
+	return ret;
+}
+
+static int ts2020_set_tuner_rf(struct dvb_frontend *fe)
+{
+	struct ts2020_priv *dev = fe->tuner_priv;
+	int ret;
+	unsigned int utmp;
+
+	ret = regmap_read(dev->regmap, 0x3d, &utmp);
+	if (ret)
+		return ret;
+
+	utmp &= 0x7f;
+	if (utmp < 0x16)
+		utmp = 0xa1;
+	else if (utmp == 0x16)
+		utmp = 0x99;
+	else
+		utmp = 0xf9;
+
+	regmap_write(dev->regmap, 0x60, utmp);
+	ret = ts2020_tuner_gate_ctrl(fe, 0x08);
+
+	return ret;
+}
+
+static int ts2020_set_params(struct dvb_frontend *fe)
+{
+	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+	struct ts2020_priv *priv = fe->tuner_priv;
+	int ret;
+	unsigned int utmp;
+	u32 f3db, gdiv28;
+	u16 u16tmp, value, lpf_coeff;
+	u8 buf[3], reg10, lpf_mxdiv, mlpf_max, mlpf_min, nlpf;
+	unsigned int f_ref_khz, f_vco_khz, div_ref, div_out, pll_n;
+	unsigned int frequency_khz = c->frequency;
+
+	/*
+	 * Integer-N PLL synthesizer
+	 * kHz is used for all calculations to keep calculations within 32-bit
+	 */
+	f_ref_khz = TS2020_XTAL_FREQ;
+	div_ref = DIV_ROUND_CLOSEST(f_ref_khz, 2000);
+
+	/* select LO output divider */
+	if (frequency_khz < priv->frequency_div) {
+		div_out = 4;
+		reg10 = 0x10;
+	} else {
+		div_out = 2;
+		reg10 = 0x00;
+	}
+
+	f_vco_khz = frequency_khz * div_out;
+	pll_n = f_vco_khz * div_ref / f_ref_khz;
+	pll_n += pll_n % 2;
+	priv->frequency_khz = pll_n * f_ref_khz / div_ref / div_out;
+
+	pr_debug("frequency=%u offset=%d f_vco_khz=%u pll_n=%u div_ref=%u div_out=%u\n",
+		 priv->frequency_khz, priv->frequency_khz - c->frequency,
+		 f_vco_khz, pll_n, div_ref, div_out);
+
+	if (priv->tuner == TS2020_M88TS2020) {
+		lpf_coeff = 2766;
+		reg10 |= 0x01;
+		ret = regmap_write(priv->regmap, 0x10, reg10);
+	} else {
+		lpf_coeff = 3200;
+		reg10 |= 0x0b;
+		ret = regmap_write(priv->regmap, 0x10, reg10);
+		ret |= regmap_write(priv->regmap, 0x11, 0x40);
+	}
+
+	u16tmp = pll_n - 1024;
+	buf[0] = (u16tmp >> 8) & 0xff;
+	buf[1] = (u16tmp >> 0) & 0xff;
+	buf[2] = div_ref - 8;
+
+	ret |= regmap_write(priv->regmap, 0x01, buf[0]);
+	ret |= regmap_write(priv->regmap, 0x02, buf[1]);
+	ret |= regmap_write(priv->regmap, 0x03, buf[2]);
+
+	ret |= ts2020_tuner_gate_ctrl(fe, 0x10);
+	if (ret < 0)
+		return -ENODEV;
+
+	ret |= ts2020_tuner_gate_ctrl(fe, 0x08);
+
+	/* Tuner RF */
+	if (priv->tuner == TS2020_M88TS2020)
+		ret |= ts2020_set_tuner_rf(fe);
+
+	gdiv28 = (TS2020_XTAL_FREQ / 1000 * 1694 + 500) / 1000;
+	ret |= regmap_write(priv->regmap, 0x04, gdiv28 & 0xff);
+	ret |= ts2020_tuner_gate_ctrl(fe, 0x04);
+	if (ret < 0)
+		return -ENODEV;
+
+	if (priv->tuner == TS2020_M88TS2022) {
+		ret = regmap_write(priv->regmap, 0x25, 0x00);
+		ret |= regmap_write(priv->regmap, 0x27, 0x70);
+		ret |= regmap_write(priv->regmap, 0x41, 0x09);
+		ret |= regmap_write(priv->regmap, 0x08, 0x0b);
+		if (ret < 0)
+			return -ENODEV;
+	}
+
+	regmap_read(priv->regmap, 0x26, &utmp);
+	value = utmp;
+
+	f3db = (c->bandwidth_hz / 1000 / 2) + 2000;
+	f3db += FREQ_OFFSET_LOW_SYM_RATE; /* FIXME: ~always too wide filter */
+	f3db = clamp(f3db, 7000U, 40000U);
+
+	gdiv28 = gdiv28 * 207 / (value * 2 + 151);
+	mlpf_max = gdiv28 * 135 / 100;
+	mlpf_min = gdiv28 * 78 / 100;
+	if (mlpf_max > 63)
+		mlpf_max = 63;
+
+	nlpf = (f3db * gdiv28 * 2 / lpf_coeff /
+		(TS2020_XTAL_FREQ / 1000)  + 1) / 2;
+	if (nlpf > 23)
+		nlpf = 23;
+	if (nlpf < 1)
+		nlpf = 1;
+
+	lpf_mxdiv = (nlpf * (TS2020_XTAL_FREQ / 1000)
+		* lpf_coeff * 2  / f3db + 1) / 2;
+
+	if (lpf_mxdiv < mlpf_min) {
+		nlpf++;
+		lpf_mxdiv = (nlpf * (TS2020_XTAL_FREQ / 1000)
+			* lpf_coeff * 2  / f3db + 1) / 2;
+	}
+
+	if (lpf_mxdiv > mlpf_max)
+		lpf_mxdiv = mlpf_max;
+
+	ret = regmap_write(priv->regmap, 0x04, lpf_mxdiv);
+	ret |= regmap_write(priv->regmap, 0x06, nlpf);
+
+	ret |= ts2020_tuner_gate_ctrl(fe, 0x04);
+
+	ret |= ts2020_tuner_gate_ctrl(fe, 0x01);
+
+	msleep(80);
+
+	return (ret < 0) ? -EINVAL : 0;
+}
+
+static int ts2020_get_frequency(struct dvb_frontend *fe, u32 *frequency)
+{
+	struct ts2020_priv *priv = fe->tuner_priv;
+
+	*frequency = priv->frequency_khz;
+	return 0;
+}
+
+static int ts2020_get_if_frequency(struct dvb_frontend *fe, u32 *frequency)
+{
+	*frequency = 0; /* Zero-IF */
+	return 0;
+}
+
+/*
+ * Get the tuner gain.
+ * @fe: The front end for which we're determining the gain
+ * @v_agc: The voltage of the AGC from the demodulator (0-2600mV)
+ * @_gain: Where to store the gain (in 0.001dB units)
+ *
+ * Returns 0 or a negative error code.
+ */
+static int ts2020_read_tuner_gain(struct dvb_frontend *fe, unsigned v_agc,
+				  __s64 *_gain)
+{
+	struct ts2020_priv *priv = fe->tuner_priv;
+	unsigned long gain1, gain2, gain3;
+	unsigned utmp;
+	int ret;
+
+	/* Read the RF gain */
+	ret = regmap_read(priv->regmap, 0x3d, &utmp);
+	if (ret < 0)
+		return ret;
+	gain1 = utmp & 0x1f;
+
+	/* Read the baseband gain */
+	ret = regmap_read(priv->regmap, 0x21, &utmp);
+	if (ret < 0)
+		return ret;
+	gain2 = utmp & 0x1f;
+
+	switch (priv->tuner) {
+	case TS2020_M88TS2020:
+		gain1 = clamp_t(long, gain1, 0, 15);
+		gain2 = clamp_t(long, gain2, 0, 13);
+		v_agc = clamp_t(long, v_agc, 400, 1100);
+
+		*_gain = -((__s64)gain1 * 2330 +
+			   gain2 * 3500 +
+			   v_agc * 24 / 10 * 10 +
+			   10000);
+		/* gain in range -19600 to -116850 in units of 0.001dB */
+		break;
+
+	case TS2020_M88TS2022:
+		ret = regmap_read(priv->regmap, 0x66, &utmp);
+		if (ret < 0)
+			return ret;
+		gain3 = (utmp >> 3) & 0x07;
+
+		gain1 = clamp_t(long, gain1, 0, 15);
+		gain2 = clamp_t(long, gain2, 2, 16);
+		gain3 = clamp_t(long, gain3, 0, 6);
+		v_agc = clamp_t(long, v_agc, 600, 1600);
+
+		*_gain = -((__s64)gain1 * 2650 +
+			   gain2 * 3380 +
+			   gain3 * 2850 +
+			   v_agc * 176 / 100 * 10 -
+			   30000);
+		/* gain in range -47320 to -158950 in units of 0.001dB */
+		break;
+	}
+
+	return 0;
+}
+
+/*
+ * Get the AGC information from the demodulator and use that to calculate the
+ * tuner gain.
+ */
+static int ts2020_get_tuner_gain(struct dvb_frontend *fe, __s64 *_gain)
+{
+	struct ts2020_priv *priv = fe->tuner_priv;
+	int v_agc = 0, ret;
+	u8 agc_pwm;
+
+	/* Read the AGC PWM rate from the demodulator */
+	if (priv->get_agc_pwm) {
+		ret = priv->get_agc_pwm(fe, &agc_pwm);
+		if (ret < 0)
+			return ret;
+
+		switch (priv->tuner) {
+		case TS2020_M88TS2020:
+			v_agc = (int)agc_pwm * 20 - 1166;
+			break;
+		case TS2020_M88TS2022:
+			v_agc = (int)agc_pwm * 16 - 670;
+			break;
+		}
+
+		if (v_agc < 0)
+			v_agc = 0;
+	}
+
+	return ts2020_read_tuner_gain(fe, v_agc, _gain);
+}
+
+/*
+ * Gather statistics on a regular basis
+ */
+static void ts2020_stat_work(struct work_struct *work)
+{
+	struct ts2020_priv *priv = container_of(work, struct ts2020_priv,
+					       stat_work.work);
+	struct i2c_client *client = priv->client;
+	struct dtv_frontend_properties *c = &priv->fe->dtv_property_cache;
+	int ret;
+
+	dev_dbg(&client->dev, "\n");
+
+	ret = ts2020_get_tuner_gain(priv->fe, &c->strength.stat[0].svalue);
+	if (ret < 0)
+		goto err;
+
+	c->strength.stat[0].scale = FE_SCALE_DECIBEL;
+
+	if (!priv->dont_poll)
+		schedule_delayed_work(&priv->stat_work, msecs_to_jiffies(2000));
+	return;
+err:
+	dev_dbg(&client->dev, "failed=%d\n", ret);
+}
+
+/*
+ * Read TS2020 signal strength in v3 format.
+ */
+static int ts2020_read_signal_strength(struct dvb_frontend *fe,
+				       u16 *_signal_strength)
+{
+	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+	struct ts2020_priv *priv = fe->tuner_priv;
+	unsigned strength;
+	__s64 gain;
+
+	if (priv->dont_poll)
+		ts2020_stat_work(&priv->stat_work.work);
+
+	if (c->strength.stat[0].scale == FE_SCALE_NOT_AVAILABLE) {
+		*_signal_strength = 0;
+		return 0;
+	}
+
+	gain = c->strength.stat[0].svalue;
+
+	/* Calculate the signal strength based on the total gain of the tuner */
+	if (gain < -85000)
+		/* 0%: no signal or weak signal */
+		strength = 0;
+	else if (gain < -65000)
+		/* 0% - 60%: weak signal */
+		strength = 0 + div64_s64((85000 + gain) * 3, 1000);
+	else if (gain < -45000)
+		/* 60% - 90%: normal signal */
+		strength = 60 + div64_s64((65000 + gain) * 3, 2000);
+	else
+		/* 90% - 99%: strong signal */
+		strength = 90 + div64_s64((45000 + gain), 5000);
+
+	*_signal_strength = strength * 65535 / 100;
+	return 0;
+}
+
+static const struct dvb_tuner_ops ts2020_tuner_ops = {
+	.info = {
+		.name = "TS2020",
+		.frequency_min_hz =  950 * MHz,
+		.frequency_max_hz = 2150 * MHz
+	},
+	.init = ts2020_init,
+	.release = ts2020_release,
+	.sleep = ts2020_sleep,
+	.set_params = ts2020_set_params,
+	.get_frequency = ts2020_get_frequency,
+	.get_if_frequency = ts2020_get_if_frequency,
+	.get_rf_strength = ts2020_read_signal_strength,
+};
+
+struct dvb_frontend *ts2020_attach(struct dvb_frontend *fe,
+					const struct ts2020_config *config,
+					struct i2c_adapter *i2c)
+{
+	struct i2c_client *client;
+	struct i2c_board_info board_info;
+
+	/* This is only used by ts2020_probe() so can be on the stack */
+	struct ts2020_config pdata;
+
+	memcpy(&pdata, config, sizeof(pdata));
+	pdata.fe = fe;
+	pdata.attach_in_use = true;
+
+	memset(&board_info, 0, sizeof(board_info));
+	strscpy(board_info.type, "ts2020", I2C_NAME_SIZE);
+	board_info.addr = config->tuner_address;
+	board_info.platform_data = &pdata;
+	client = i2c_new_client_device(i2c, &board_info);
+	if (!i2c_client_has_driver(client))
+		return NULL;
+
+	return fe;
+}
+EXPORT_SYMBOL_GPL(ts2020_attach);
+
+/*
+ * We implement own regmap locking due to legacy DVB attach which uses frontend
+ * gate control callback to control I2C bus access. We can open / close gate and
+ * serialize whole open / I2C-operation / close sequence at the same.
+ */
+static void ts2020_regmap_lock(void *__dev)
+{
+	struct ts2020_priv *dev = __dev;
+
+	mutex_lock(&dev->regmap_mutex);
+	if (dev->fe->ops.i2c_gate_ctrl)
+		dev->fe->ops.i2c_gate_ctrl(dev->fe, 1);
+}
+
+static void ts2020_regmap_unlock(void *__dev)
+{
+	struct ts2020_priv *dev = __dev;
+
+	if (dev->fe->ops.i2c_gate_ctrl)
+		dev->fe->ops.i2c_gate_ctrl(dev->fe, 0);
+	mutex_unlock(&dev->regmap_mutex);
+}
+
+static int ts2020_probe(struct i2c_client *client)
+{
+	struct ts2020_config *pdata = client->dev.platform_data;
+	struct dvb_frontend *fe;
+	struct ts2020_priv *dev;
+	int ret;
+	u8 u8tmp;
+	unsigned int utmp;
+	char *chip_str;
+
+	if (!pdata) {
+		dev_err(&client->dev, "platform data is mandatory\n");
+		return -EINVAL;
+	}
+
+	fe = pdata->fe;
+	dev = kzalloc_obj(*dev);
+	if (!dev) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	/* create regmap */
+	mutex_init(&dev->regmap_mutex);
+	dev->regmap_config.reg_bits = 8;
+	dev->regmap_config.val_bits = 8;
+	dev->regmap_config.lock = ts2020_regmap_lock;
+	dev->regmap_config.unlock = ts2020_regmap_unlock;
+	dev->regmap_config.lock_arg = dev;
+	dev->regmap = regmap_init_i2c(client, &dev->regmap_config);
+	if (IS_ERR(dev->regmap)) {
+		ret = PTR_ERR(dev->regmap);
+		goto err_kfree;
+	}
+
+	dev->i2c = client->adapter;
+	dev->i2c_address = client->addr;
+	dev->loop_through = pdata->loop_through;
+	dev->clk_out = pdata->clk_out;
+	dev->clk_out_div = pdata->clk_out_div;
+	dev->dont_poll = pdata->dont_poll;
+	dev->frequency_div = pdata->frequency_div;
+	dev->fe = fe;
+	dev->get_agc_pwm = pdata->get_agc_pwm;
+	fe->tuner_priv = dev;
+	dev->client = client;
+	INIT_DELAYED_WORK(&dev->stat_work, ts2020_stat_work);
+
+	/* check if the tuner is there */
+	ret = regmap_read(dev->regmap, 0x00, &utmp);
+	if (ret)
+		goto err_regmap_exit;
+
+	if ((utmp & 0x03) == 0x00) {
+		ret = regmap_write(dev->regmap, 0x00, 0x01);
+		if (ret)
+			goto err_regmap_exit;
+
+		usleep_range(2000, 50000);
+	}
+
+	ret = regmap_write(dev->regmap, 0x00, 0x03);
+	if (ret)
+		goto err_regmap_exit;
+
+	usleep_range(2000, 50000);
+
+	ret = regmap_read(dev->regmap, 0x00, &utmp);
+	if (ret)
+		goto err_regmap_exit;
+
+	dev_dbg(&client->dev, "chip_id=%02x\n", utmp);
+
+	switch (utmp) {
+	case 0x01:
+	case 0x41:
+	case 0x81:
+		dev->tuner = TS2020_M88TS2020;
+		chip_str = "TS2020";
+		if (!dev->frequency_div)
+			dev->frequency_div = 1060000;
+		break;
+	case 0xc3:
+	case 0x83:
+		dev->tuner = TS2020_M88TS2022;
+		chip_str = "TS2022";
+		if (!dev->frequency_div)
+			dev->frequency_div = 1103000;
+		break;
+	default:
+		ret = -ENODEV;
+		goto err_regmap_exit;
+	}
+
+	if (dev->tuner == TS2020_M88TS2022) {
+		switch (dev->clk_out) {
+		case TS2020_CLK_OUT_DISABLED:
+			u8tmp = 0x60;
+			break;
+		case TS2020_CLK_OUT_ENABLED:
+			u8tmp = 0x70;
+			ret = regmap_write(dev->regmap, 0x05, dev->clk_out_div);
+			if (ret)
+				goto err_regmap_exit;
+			break;
+		case TS2020_CLK_OUT_ENABLED_XTALOUT:
+			u8tmp = 0x6c;
+			break;
+		default:
+			ret = -EINVAL;
+			goto err_regmap_exit;
+		}
+
+		ret = regmap_write(dev->regmap, 0x42, u8tmp);
+		if (ret)
+			goto err_regmap_exit;
+
+		if (dev->loop_through)
+			u8tmp = 0xec;
+		else
+			u8tmp = 0x6c;
+
+		ret = regmap_write(dev->regmap, 0x62, u8tmp);
+		if (ret)
+			goto err_regmap_exit;
+	}
+
+	/* sleep */
+	ret = regmap_write(dev->regmap, 0x00, 0x00);
+	if (ret)
+		goto err_regmap_exit;
+
+	dev_info(&client->dev,
+		 "Montage Technology %s successfully identified\n", chip_str);
+
+	memcpy(&fe->ops.tuner_ops, &ts2020_tuner_ops,
+			sizeof(struct dvb_tuner_ops));
+	if (!pdata->attach_in_use)
+		fe->ops.tuner_ops.release = NULL;
+
+	i2c_set_clientdata(client, dev);
+	return 0;
+err_regmap_exit:
+	regmap_exit(dev->regmap);
+err_kfree:
+	kfree(dev);
+err:
+	dev_dbg(&client->dev, "failed=%d\n", ret);
+	return ret;
+}
+
+static void ts2020_remove(struct i2c_client *client)
+{
+	struct ts2020_priv *dev = i2c_get_clientdata(client);
+
+	dev_dbg(&client->dev, "\n");
+
+	/* stop statistics polling */
+	if (!dev->dont_poll)
+		cancel_delayed_work_sync(&dev->stat_work);
+
+	regmap_exit(dev->regmap);
+	kfree(dev);
+}
+
+static const struct i2c_device_id ts2020_id_table[] = {
+	{ .name = "ts2020" },
+	{ .name = "ts2022" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ts2020_id_table);
+
+static struct i2c_driver ts2020_driver = {
+	.driver = {
+		.name	= "ts2020",
+	},
+	.probe		= ts2020_probe,
+	.remove		= ts2020_remove,
+	.id_table	= ts2020_id_table,
+};
+
+module_i2c_driver(ts2020_driver);
+
+MODULE_AUTHOR("Konstantin Dimitrov <kosio.dimitrov@gmail.com>");
+MODULE_DESCRIPTION("Montage Technology TS2020 - Silicon tuner driver module");
+MODULE_LICENSE("GPL");