diff mbox series

[3/3] media: Add support for the AM/FM radio chip KT0913 from KT Micro.

Message ID 20200803020921.64151-4-santiagohssl@gmail.com
State New
Headers show
Series [1/3] dt-bindings: vendor-prefixes: Add KT Micro | expand

Commit Message

Santiago Hormazabal Aug. 3, 2020, 2:09 a.m. UTC
This chip requires almost no support components and can used over I2C.
The driver uses the I2C bus and exposes the controls as a V4L2 radio.
Tested with a module that contains this chip (from SZZSJDZ.com,
part number ZJ-801B, even tho the company seems defunct now), and an H2+
AllWinner SoC running a kernel built off 8f2a4a9 of the media_tree.

Signed-off-by: Santiago Hormazabal <santiagohssl@gmail.com>
---
 drivers/media/radio/Kconfig        |   10 +
 drivers/media/radio/Makefile       |    1 +
 drivers/media/radio/radio-kt0913.c | 1196 ++++++++++++++++++++++++++++
 3 files changed, 1207 insertions(+)
 create mode 100644 drivers/media/radio/radio-kt0913.c
diff mbox series

Patch

diff --git a/drivers/media/radio/Kconfig b/drivers/media/radio/Kconfig
index d29e29645e04..ac9053a95f3a 100644
--- a/drivers/media/radio/Kconfig
+++ b/drivers/media/radio/Kconfig
@@ -226,6 +226,16 @@  config RADIO_WL1273
 # TI's ST based wl128x FM radio
 source "drivers/media/radio/wl128x/Kconfig"
 
+config RADIO_KT0913
+	tristate "KT0913 I2C FM/AM radio support"
+	depends on I2C && VIDEO_V4L2
+	help
+	  Say Y here if you want to use the KT0913 FM/AM chip.
+	  This is a low cost chip that uses the I2C bus.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called radio-kt0913.
+
 #
 # ISA drivers configuration
 #
diff --git a/drivers/media/radio/Makefile b/drivers/media/radio/Makefile
index 53c7ae135460..a314121f7771 100644
--- a/drivers/media/radio/Makefile
+++ b/drivers/media/radio/Makefile
@@ -34,5 +34,6 @@  obj-$(CONFIG_RADIO_WL1273) += radio-wl1273.o
 obj-$(CONFIG_RADIO_WL128X) += wl128x/
 obj-$(CONFIG_RADIO_TEA575X) += tea575x.o
 obj-$(CONFIG_USB_RAREMONO) += radio-raremono.o
+obj-$(CONFIG_RADIO_KT0913) += radio-kt0913.o
 
 shark2-objs := radio-shark2.o radio-tea5777.o
diff --git a/drivers/media/radio/radio-kt0913.c b/drivers/media/radio/radio-kt0913.c
new file mode 100644
index 000000000000..e8c1ff882779
--- /dev/null
+++ b/drivers/media/radio/radio-kt0913.c
@@ -0,0 +1,1196 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * drivers/media/radio/radio-kt0913.c
+ *
+ * Driver for the KT0913 radio chip from KTMicro.
+ * This driver provides a v4l2 interface to the tuner, using the I2C
+ * protocol to communicate with the chip.
+ * It exposes two bands, one for AM and another for FM. If the "campus
+ * band" feature needs to be enabled, set the corresponding module parameter
+ * to 1.
+ * Reference Clock and Audio DAC anti-pop configurations should be
+ * set via a device tree node. Defaults will be used otherwise.
+ *
+ * Audio output should be routed to a speaker or an audio capture
+ * device.
+ *
+ * Based on radio-tea5764 by Fabio Belavenuto <belavenuto@gmail.com>
+ *
+ *  Copyright (c) 2020 Santiago Hormazabal <santiagohssl@gmail.com>
+ *
+ * TODO:
+ *  use rd and wr support for the regmap instead of volatile regs.
+ *  add support for the hardware-assisted frequency seek.
+ *  export FM SNR and AM/FM AFC deviation values as RO controls.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/math64.h>
+#include <linux/regmap.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-ioctl.h>
+#include <media/v4l2-event.h>
+
+ /* ************************************************************************* */
+
+ /* registers of the kt0913 */
+#define KT0913_REG_CHIP_ID      0x01
+#define KT0913_REG_SEEK         0x02
+#define KT0913_REG_TUNE         0x03
+#define KT0913_REG_VOLUME       0x04
+#define KT0913_REG_DSPCFGA      0x05
+#define KT0913_REG_LOCFGA       0x0A
+#define KT0913_REG_LOCFGC       0x0C
+#define KT0913_REG_RXCFG        0x0F
+#define KT0913_REG_STATUSA      0x12
+#define KT0913_REG_STATUSB      0x13
+#define KT0913_REG_STATUSC      0x14
+#define KT0913_REG_AMSYSCFG     0x16
+#define KT0913_REG_AMCHAN       0x17
+#define KT0913_REG_AMCALI       0x18
+#define KT0913_REG_GPIOCFG      0x1D
+#define KT0913_REG_AMDSP        0x22
+#define KT0913_REG_AMSTATUSA    0x24
+#define KT0913_REG_AMSTATUSB    0x25
+#define KT0913_REG_SOFTMUTE     0x2E
+#define KT0913_REG_AMCFG        0x33
+#define KT0913_REG_AMCFG2       0x34
+#define KT0913_REG_AFC          0x3C
+
+/* register symbols masks, values and shift count */
+#define KT0913_TUNE_FMTUNE_MASK 0x8000 /* FM Tune enable */
+#define KT0913_TUNE_FMTUNE_ON 0x8000 /* FM Tune enabled */
+#define KT0913_TUNE_FMTUNE_OFF 0x0000 /* FM Tune disabled */
+#define KT0913_TUNE_FMCHAN_MASK 0x0FFF /* frequency in kHz / 50kHz */
+
+#define KT0913_VOLUME_DMUTE_MASK 0x2000
+#define KT0913_VOLUME_DMUTE_ON 0x0000
+#define KT0913_VOLUME_DMUTE_OFF 0x2000
+#define KT0913_VOLUME_DE_MASK 0x0800 /* de-emphasis time constant */
+#define KT0913_VOLUME_DE_75US 0x0000 /* 75us */
+#define KT0913_VOLUME_DE_50US 0x0800 /* 50us */
+#define KT0913_VOLUME_POP_MASK 0x30 /* audio dac anti-pop config */
+#define KT0913_VOLUME_POP_SHIFT 4
+
+#define KT0913_DSPCFGA_MONO_MASK 0x8000 /* mono select (0=stereo, 1=mono) */
+#define KT0913_DSPCFGA_MONO_ON 0x8000 /* mono */
+#define KT0913_DSPCFGA_MONO_OFF 0x0000 /* stereo */
+
+#define KT0913_LOCFG_CAMPUSBAND_EN_MASK 0x0008 /* campus band fm enable */
+#define KT0913_LOCFG_CAMPUSBAND_EN_ON 0x0008 /* FM range 64-110MHz */
+#define KT0913_LOCFG_CAMPUSBAND_EN_OFF 0x0000 /* FM range 32-110MHz */
+
+#define KT0913_RXCFGA_STDBY_MASK 0x1000 /* standby mode enable */
+#define KT0913_RXCFGA_STDBY_ON 0x1000 /* standby mode enabled */
+#define KT0913_RXCFGA_STDBY_OFF 0x0000 /* standby mode disabled */
+#define KT0913_RXCFGA_VOLUME_MASK 0x001F /* volume control */
+
+#define KT0913_STATUSA_XTAL_OK 0x8000 /* crystal ready indicator */
+#define KT0913_STATUSA_STC 0x4000 /* seek/tune complete */
+
+#define KT0913_STATUSA_PLL_LOCK_MASK 0x800 /* system pll ready indicator */
+#define KT0913_STATUSA_PLL_LOCK_LOCKED 0x800 /* system pll ready */
+#define KT0913_STATUSA_PLL_LOCK_UNLOCKED 0x000 /* not ready */
+#define KT0913_STATUSA_LO_LOCK 0x400 /* LO synthesizer ready indicator */
+#define KT0913_STATUSA_ST_MASK 0x300 /* stereo indicator (0x300=stereo, otherwise mono) */
+#define KT0913_STATUSA_ST_STEREO 0x300 /* stereo */
+#define KT0913_STATUSA_FMRSSI_MASK 0xF8 /* FM RSSI (-100dBm + FMRSSI*3dBm) */
+#define KT0913_STATUSA_FMRSSI_SHIFT 3
+
+#define KT0913_STATUSC_PWSTATUS 0x8000 /* power status indicator */
+#define KT0913_STATUSC_CHIPRDY 0x2000 /* chip ready indicator */
+#define KT0913_STATUSC_FMSNR 0x1FC0 /* FM SNR (unknown units) */
+
+#define KT0913_AMCHAN_AMTUNE_MASK 0x8000 /* AM tune enable */
+#define KT0913_AMCHAN_AMTUNE_ON 0x8000 /* AM tune enabled */
+#define KT0913_AMCHAN_AMTUNE_OFF 0x0000 /* AM tune disabled */
+#define KT0913_AMCHAN_AMCHAN_MASK 0x7FF /* am channel in kHz */
+
+#define KT0913_AMSYSCFG_AM_FM_MASK 0x8000 /* am/fm mode control */
+#define KT0913_AMSYSCFG_AM_FM_AM 0x8000 /* am mode */
+#define KT0913_AMSYSCFG_AM_FM_FM 0x0000 /* fm mode (default) */
+#define KT0913_AMSYSCFG_REFCLK_MASK 0x0F00 /* reference clock selection */
+#define KT0913_AMSYSCFG_REFCLK_SHIFT 8
+#define KT0913_AMSYSCFG_AU_GAIN_MASK 0x00C0 /* audio gain selection */
+#define KT0913_AMSYSCFG_AU_GAIN_6DB 0x0040 /* 6dB audio gain */
+#define KT0913_AMSYSCFG_AU_GAIN_3DB 0x0000 /* 3dB audio gain (default) */
+#define KT0913_AMSYSCFG_AU_GAIN_0DB 0x00C0 /* 0dB audio gain */
+#define KT0913_AMSYSCFG_AU_GAIN_MIN_3DB 0x0080 /* -3dB audio gain */
+
+#define KT0913_AMSTATUSA_AMRSSI_MASK 0x1F00 /* am channel rssi */
+#define KT0913_AMSTATUSA_AMRSSI_SHIFT 8
+
+/* constants */
+#define KT0913_CHIP_ID  0x544B /* ASCII of 'KT' */
+
+#define V4L2_KHZ_FREQ_MUL 16U /* v4l2 uses 16x the kHz value as their freq */
+#define KT0913_FMCHAN_MUL 50U /* kt0913 uses freqs with a 50kHz multiplier */
+#define KT0913_FM_RANGE_LOW_NO_CAMPUS 64000U /* 64MHz lower bound for FM */
+#define KT0913_FM_RANGE_LOW_CAMPUS 32000U /* 32MHz lower bound for campus FM */
+#define KT0913_FM_RANGE_HIGH 110000U /* 110MHz upper bound for FM */
+#define KT0913_AM_RANGE_LOW  500U /* 500kHz lower bound for AM */
+#define KT0913_AM_RANGE_HIGH 1710U /* 1710kHz upper bound for AM */
+
+#define KT0913_FM_AM_DRIVER_NAME "kt0913-fm-am"
+
+/* ************************************************************************* */
+
+/* v4l2 device number to use. -1 will assign the next free one */
+static int kt0913_v4l2_radio_nr = -1;
+/* use the extended range of FM down to 32MHz. disabled by default */
+static int kt0913_use_campus_band;
+
+/* ************************************************************************* */
+
+/* kt0913 status struct */
+struct kt0913_device {
+	struct v4l2_device v4l2_dev;		/* main v4l2 struct */
+	struct i2c_client *client;			/* I2C client */
+	struct video_device vdev;			/* vide_device struct */
+	struct v4l2_ctrl_handler ctrl_handler; /* ctrl_handler struct */
+
+	/* V4L2 Controls */
+	struct v4l2_ctrl *ctrl_pll_lock;    /* PLL lock */
+	struct v4l2_ctrl *ctrl_volume;      /* Overall volume */
+	struct v4l2_ctrl *ctrl_au_gain;     /* Audio Gain */
+	struct v4l2_ctrl *ctrl_mute;        /* Master mute */
+	struct v4l2_ctrl *ctrl_deemp;  /* Deemphasis */
+
+	/* current operation band (fm, fm_campus, am) */
+	unsigned int band;
+
+	/* audio dac anti-pop setting:
+	 *  0 -> 100uF (default)
+	 *  1 -> 60uF
+	 *  2 -> 20uF
+	 *  3 -> 10uF
+	 */
+	unsigned int audio_anti_pop;
+
+	/*
+	 * reference clock selection:
+	 *  0 -> 32.768kHz (default)
+	 *  1 -> 6.5MHz
+	 *  2 -> 7.6MHz
+	 *  3 -> 12MHz
+	 *  4 -> 13MHz
+	 *  5 -> 15.2MHz
+	 *  6 -> 19.2MHz
+	 *  7 -> 24MHz
+	 *  8 -> 26MHz
+	 *  9 -> 38kHz
+	 */
+	unsigned int refclock_val;
+
+	/* Regmap */
+	struct regmap *regmap;
+
+	/* For core assisted locking */
+	struct mutex mutex;
+};
+
+/* ************************************************************************* */
+
+/* Regmap settings */
+static const struct regmap_range kt0913_regmap_all_registers_range[] = {
+	regmap_reg_range(0x01, 0x05),
+	regmap_reg_range(0x0A, 0x0A),
+	regmap_reg_range(0x0C, 0x0C),
+	regmap_reg_range(0x0F, 0x0F),
+	regmap_reg_range(0x12, 0x14),
+	regmap_reg_range(0x16, 0x18),
+	regmap_reg_range(0x1D, 0x1D),
+	regmap_reg_range(0x22, 0x22),
+	regmap_reg_range(0x24, 0x25),
+	regmap_reg_range(0x2E, 0x2F),
+	regmap_reg_range(0x30, 0x34),
+	regmap_reg_range(0x3A, 0x3A),
+	regmap_reg_range(0x3C, 0x3C),
+};
+
+static const struct regmap_access_table kt0913_all_registers_access_table = {
+	.yes_ranges = kt0913_regmap_all_registers_range,
+	.n_yes_ranges = ARRAY_SIZE(kt0913_regmap_all_registers_range),
+};
+
+static const struct reg_sequence kt0913_init_regs_to_defaults[] = {
+	/* Standby disabled, volume 0dB */
+	{ KT0913_REG_RXCFG, 0x881F },
+	/* FM Channel spacing = 50kHz, Right & Left unmuted */
+	{ KT0913_REG_SEEK, 0x000B },
+	/* Stereo, High Stereo/Mono blend level, blend disabled */
+	{ KT0913_REG_DSPCFGA, 0x1000 },
+	/* FM AFC Enabled */
+	{ KT0913_REG_LOCFGA, 0x0100 },
+	/* Campus band disabled by default */
+	{ KT0913_REG_LOCFGC, 0x0024 },
+	/*
+	 * FM mode, internal defined bands, clock from XT, 32.768kHz
+	 * 3dB audio gain, AM AFC Enabled
+	 */
+	{ KT0913_REG_AMSYSCFG, 0x0002 },
+	/* Default AM freq = 504kHz */
+	{ KT0913_REG_AMCHAN, 0x01F8},
+	/* VOL and CH GPIOs set to HiZ */
+	{ KT0913_REG_GPIOCFG, 0x0000 },
+	/* AM Channel bandwidth = 6kHz, non-differential output */
+	{ KT0913_REG_AMDSP, 0xAFC4 },
+	/*
+	 * softmute is disabled on AM and FM, but set the defaults:
+	 * strong softmute attn., slow softmute attack/recover,
+	 * lowest AM softumte start level, almost the minimum
+	 * softmute target volume, RSSI mode for softmute, lowest
+	 * FM softmute start level
+	 */
+	{ KT0913_REG_SOFTMUTE, 0x0010 },
+	/* 1kHz for AM channel space, working mode A for the keys */
+	{ KT0913_REG_AMCFG, 0x1401 },
+	/* TIME1 = shortest, TIME2 = fastest */
+	{ KT0913_REG_AMCFG, 0x4050 },
+	/* set 86MHz as the default frequency, and tune it */
+	{ KT0913_REG_TUNE, 0x86B8 },
+	/*
+	 * FM&AM Softmute disabled, Mute disabled, 75us deemp.,
+	 * no bass boost, 100uF anti pop cap
+	 */
+	{ KT0913_REG_VOLUME, 0xE080 },
+};
+
+static const struct regmap_config kt0913_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 16,
+	.max_register = KT0913_REG_AFC,
+	.volatile_table = &kt0913_all_registers_access_table,
+	.cache_type = REGCACHE_RBTREE,
+	.val_format_endian = REGMAP_ENDIAN_BIG,
+};
+
+/* ************************************************************************* */
+
+/* bands where the kt0913 operates */
+enum { BAND_FM, BAND_FM_CAMUS, BAND_AM };
+
+static const struct v4l2_frequency_band kt0913_bands[] = {
+	{
+		/* BAND_FM */
+		.type = V4L2_TUNER_RADIO,
+		.index = 0, /* index provided to v4l2 */
+		.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
+				V4L2_TUNER_CAP_FREQ_BANDS,
+		.rangelow = KT0913_FM_RANGE_LOW_NO_CAMPUS * V4L2_KHZ_FREQ_MUL,
+		.rangehigh = KT0913_FM_RANGE_HIGH * V4L2_KHZ_FREQ_MUL,
+		.modulation = V4L2_BAND_MODULATION_FM,
+	},
+	{
+		/* BAND_FM_CAMUS */
+		.type = V4L2_TUNER_RADIO,
+		.index = 0, /* index provided to v4l2 */
+		.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
+				V4L2_TUNER_CAP_FREQ_BANDS,
+		.rangelow = KT0913_FM_RANGE_LOW_CAMPUS * V4L2_KHZ_FREQ_MUL,
+		.rangehigh = KT0913_FM_RANGE_HIGH * V4L2_KHZ_FREQ_MUL,
+		.modulation = V4L2_BAND_MODULATION_FM,
+	},
+	{
+		/* BAND_AM */
+		.type = V4L2_TUNER_RADIO,
+		.index = 1, /* index provided to v4l2 */
+		.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_FREQ_BANDS,
+		.rangelow = KT0913_AM_RANGE_LOW * V4L2_KHZ_FREQ_MUL,
+		.rangehigh = KT0913_AM_RANGE_HIGH * V4L2_KHZ_FREQ_MUL,
+		.modulation = V4L2_BAND_MODULATION_AM,
+	},
+};
+
+/* ************************************************************************* */
+
+static inline struct kt0913_device *
+v4l2_device_to_device(struct v4l2_device *v4l2_dev)
+{
+	return container_of(v4l2_dev,
+		struct kt0913_device, v4l2_dev);
+}
+
+static inline struct kt0913_device *
+v4l2_ctrl_to_device(struct v4l2_ctrl *ctrl_handler)
+{
+	return container_of(ctrl_handler->handler,
+		struct kt0913_device, ctrl_handler);
+}
+
+/* ************************************************************************* */
+
+static inline u32 khz_to_v4l2_freq(unsigned int freq)
+{
+	return freq * V4L2_KHZ_FREQ_MUL;
+}
+
+static inline unsigned int v4l2_freq_to_khz(u32 v4l2_freq)
+{
+	return v4l2_freq / V4L2_KHZ_FREQ_MUL;
+}
+
+/* ************************************************************************* */
+
+static int __kt0913_get_fm_frequency(struct kt0913_device *radio,
+				     unsigned int *frequency)
+{
+	unsigned int tune_reg;
+	int ret = regmap_read(radio->regmap, KT0913_REG_TUNE, &tune_reg);
+
+	if (ret)
+		return ret;
+
+	*frequency = (tune_reg & KT0913_TUNE_FMCHAN_MASK) * KT0913_FMCHAN_MUL;
+
+	return 0;
+}
+
+static int __kt0913_set_fm_frequency(struct kt0913_device *radio,
+				     unsigned int frequency)
+{
+	return regmap_write(radio->regmap, KT0913_REG_TUNE,
+		KT0913_TUNE_FMTUNE_ON | (frequency / KT0913_FMCHAN_MUL));
+}
+
+/* ************************************************************************* */
+
+static int __kt0913_set_mute(struct kt0913_device *radio, int on)
+{
+	return regmap_update_bits(radio->regmap,
+		KT0913_REG_VOLUME, KT0913_VOLUME_DMUTE_MASK,
+		on ? KT0913_VOLUME_DMUTE_ON : KT0913_VOLUME_DMUTE_OFF);
+}
+
+/* ************************************************************************* */
+
+static int __kt0913_set_deemphasis(struct kt0913_device *radio, s32 deemp)
+{
+	switch (deemp) {
+	case V4L2_DEEMPHASIS_75_uS:
+		return regmap_update_bits(radio->regmap,
+			KT0913_REG_VOLUME, KT0913_VOLUME_DE_MASK,
+			KT0913_VOLUME_DE_50US);
+
+		/* 50us is used for the disabled option (which is not supported
+		 * on the chip) and the 50uS value
+		 */
+	default:
+		return regmap_update_bits(radio->regmap,
+			KT0913_REG_VOLUME, KT0913_VOLUME_DE_MASK,
+			KT0913_VOLUME_DE_75US);
+	}
+}
+
+/* ************************************************************************* */
+
+static int __kt0913_set_volume(struct kt0913_device *radio, s32 volume)
+{
+	/* map [-60, 0] to [1, 31] which is what the kt0913 expects */
+	volume = (volume / 2) + 31;
+	return regmap_update_bits(radio->regmap,
+		KT0913_REG_RXCFG, KT0913_RXCFGA_VOLUME_MASK,
+		volume);
+}
+
+/* ************************************************************************* */
+
+static int __kt0913_set_standby(struct kt0913_device *radio, int standby)
+{
+	return regmap_update_bits(radio->regmap,
+		KT0913_REG_RXCFG, KT0913_RXCFGA_STDBY_MASK,
+		standby ? KT0913_RXCFGA_STDBY_ON : KT0913_RXCFGA_STDBY_OFF);
+}
+
+/* ************************************************************************* */
+
+static int __kt0913_get_pll_status(struct kt0913_device *radio, int *locked)
+{
+	unsigned int statusa_reg;
+	int ret = regmap_read(radio->regmap, KT0913_REG_STATUSA, &statusa_reg);
+
+	if (ret)
+		return ret;
+
+	*locked = (statusa_reg & KT0913_STATUSA_PLL_LOCK_MASK) ==
+		KT0913_STATUSA_PLL_LOCK_LOCKED ? 1 : 0;
+
+	return 0;
+}
+
+/* ************************************************************************* */
+
+static int __kt0913_get_rx_stereo_or_mono(struct kt0913_device *radio,
+					  int *stereo)
+{
+	unsigned int statusa_reg;
+	int ret = regmap_read(radio->regmap, KT0913_REG_STATUSA, &statusa_reg);
+
+	if (ret)
+		return ret;
+
+	*stereo = (statusa_reg & KT0913_STATUSA_ST_MASK) ==
+		KT0913_STATUSA_ST_STEREO ? 1 : 0;
+
+	return 0;
+}
+
+/* ************************************************************************* */
+
+static int __kt0913_get_fm_rssi(struct kt0913_device *radio, s32 *rssi)
+{
+	unsigned int statusa_reg;
+	int ret = regmap_read(radio->regmap, KT0913_REG_STATUSA, &statusa_reg);
+
+	if (ret)
+		return ret;
+
+	/* RSSI(dBm) = -100 + FMRSSI<4:0> * 3dBm
+	 * even tho we can get the value in dBm, we want a %
+	 */
+	*rssi = (statusa_reg & KT0913_STATUSA_FMRSSI_MASK) >>
+		KT0913_STATUSA_FMRSSI_SHIFT;
+	/* map range 0-31 to 0-65535 */
+	*rssi *= 65535;
+	*rssi /= KT0913_STATUSA_FMRSSI_MASK >> KT0913_STATUSA_FMRSSI_SHIFT;
+
+	return 0;
+}
+
+/* ************************************************************************* */
+
+static int __kt0913_get_cfg_stereo_enabled(struct kt0913_device *radio,
+					   int *stereo)
+{
+	unsigned int dspcfga_reg;
+	int ret = regmap_read(radio->regmap, KT0913_REG_DSPCFGA, &dspcfga_reg);
+
+	if (ret)
+		return ret;
+
+	*stereo = (dspcfga_reg & KT0913_DSPCFGA_MONO_MASK) ==
+		KT0913_DSPCFGA_MONO_OFF ? 1 : 0;
+
+	return ret;
+}
+
+static int __kt0913_set_cfg_stereo_enabled(struct kt0913_device *radio,
+					   int stereo)
+{
+	return regmap_update_bits(radio->regmap,
+		KT0913_REG_DSPCFGA, KT0913_DSPCFGA_MONO_MASK,
+		stereo ? KT0913_DSPCFGA_MONO_OFF : KT0913_DSPCFGA_MONO_ON);
+}
+
+/* ************************************************************************* */
+
+static int __kt0913_set_au_gain(struct kt0913_device *radio, s32 gain)
+{
+	switch (gain) {
+	case 6:
+		return regmap_update_bits(radio->regmap,
+			KT0913_REG_AMSYSCFG, KT0913_AMSYSCFG_AU_GAIN_MASK,
+			KT0913_AMSYSCFG_AU_GAIN_6DB);
+	case 3:
+		return regmap_update_bits(radio->regmap,
+			KT0913_REG_AMSYSCFG, KT0913_AMSYSCFG_AU_GAIN_MASK,
+			KT0913_AMSYSCFG_AU_GAIN_3DB);
+	case 0:
+		return regmap_update_bits(radio->regmap,
+			KT0913_REG_AMSYSCFG, KT0913_AMSYSCFG_AU_GAIN_MASK,
+			KT0913_AMSYSCFG_AU_GAIN_0DB);
+	case -3:
+		return regmap_update_bits(radio->regmap,
+			KT0913_REG_AMSYSCFG, KT0913_AMSYSCFG_AU_GAIN_MASK,
+			KT0913_AMSYSCFG_AU_GAIN_MIN_3DB);
+	default:
+		return -EINVAL;
+	}
+}
+
+/* ************************************************************************* */
+
+static int __kt0913_set_am_fm_band(struct kt0913_device *radio,
+				   unsigned int band)
+{
+	return regmap_update_bits(radio->regmap,
+		KT0913_REG_AMSYSCFG, KT0913_AMSYSCFG_AM_FM_MASK,
+		band == BAND_AM ?
+		KT0913_AMSYSCFG_AM_FM_AM : KT0913_AMSYSCFG_AM_FM_FM);
+}
+
+/* ************************************************************************* */
+
+static int __kt0913_get_am_frequency(struct kt0913_device *radio,
+				     unsigned int *frequency)
+{
+	unsigned int amchan_reg;
+	int ret = regmap_read(radio->regmap, KT0913_REG_AMCHAN, &amchan_reg);
+
+	if (ret)
+		return ret;
+
+	*frequency = (amchan_reg & KT0913_AMCHAN_AMCHAN_MASK);
+
+	return 0;
+}
+
+static int __kt0913_set_am_frequency(struct kt0913_device *radio,
+				     unsigned int frequency)
+{
+	return regmap_write(radio->regmap, KT0913_REG_AMCHAN,
+		KT0913_AMCHAN_AMTUNE_ON | frequency);
+}
+
+/* ************************************************************************* */
+
+static int __kt0913_get_am_rssi(struct kt0913_device *radio, s32 *rssi)
+{
+	unsigned int amstatusa_reg;
+	int ret = regmap_read(radio->regmap,
+		KT0913_REG_AMSTATUSA, &amstatusa_reg);
+
+	if (ret)
+		return ret;
+
+	/* AMRSSI(dBm) = -90 + AMRSSI<4:0> * 3dBm
+	 * even tho we can get the value in dBm, we want a %
+	 */
+	*rssi = (amstatusa_reg & KT0913_AMSTATUSA_AMRSSI_MASK) >>
+		 KT0913_AMSTATUSA_AMRSSI_SHIFT;
+	/* map range 0-31 to 0-65535 */
+	*rssi *= 65535;
+	*rssi /= KT0913_AMSTATUSA_AMRSSI_MASK >> KT0913_AMSTATUSA_AMRSSI_SHIFT;
+
+	return 0;
+}
+
+/* ************************************************************************* */
+
+static int __kt0913_init(struct kt0913_device *radio)
+{
+	int ret = 0;
+
+	/* write the defaults */
+	ret = regmap_multi_reg_write(radio->regmap,
+				     kt0913_init_regs_to_defaults,
+				     ARRAY_SIZE(kt0913_init_regs_to_defaults));
+	if (ret) {
+		v4l2_err(radio->client,
+			 "regmap_multi_reg_write() failed! %d", ret);
+		return ret;
+	}
+
+	/* set the audio dac anti-pop config */
+	ret = regmap_update_bits(radio->regmap,
+				 KT0913_REG_VOLUME, KT0913_VOLUME_POP_MASK,
+				 radio->audio_anti_pop <<
+				 KT0913_VOLUME_POP_SHIFT);
+	if (ret) {
+		v4l2_err(radio->client,
+			 "regmap_update_bits() err on anti-pop cfg! %d", ret);
+		return ret;
+	}
+
+	/* set the reference clock config */
+	ret = regmap_update_bits(radio->regmap,
+				 KT0913_REG_AMSYSCFG,
+				 KT0913_AMSYSCFG_REFCLK_MASK,
+				 radio->refclock_val <<
+				 KT0913_AMSYSCFG_REFCLK_SHIFT);
+	if (ret) {
+		v4l2_err(radio->client,
+			 "regmap_update_bits() err on refclk cfg! %d", ret);
+		return ret;
+	}
+
+	if (kt0913_use_campus_band) {
+		v4l2_info(radio->client,
+			  "campus band is enabled!");
+		/* set the campus band bit */
+		ret = regmap_update_bits(radio->regmap,
+					 KT0913_REG_LOCFGC,
+					 KT0913_LOCFG_CAMPUSBAND_EN_MASK,
+					 KT0913_LOCFG_CAMPUSBAND_EN_ON);
+		if (ret) {
+			v4l2_err(radio->client,
+				 "regmap_update_bits() err on campus band! %d",
+				 ret);
+			return ret;
+		}
+	}
+
+	return __kt0913_set_mute(radio, true);
+}
+
+/* ************************************************************************* */
+
+static int kt0913_ioctl_vidioc_g_frequency(struct file *file, void *priv,
+					   struct v4l2_frequency *f)
+{
+	struct kt0913_device *radio = video_drvdata(file);
+	int ret;
+
+	if (f->tuner != 0)
+		return -EINVAL;
+
+	f->type = V4L2_TUNER_RADIO;
+
+	if (radio->band == BAND_AM)
+		ret = __kt0913_get_am_frequency(radio, &f->frequency);
+	else
+		ret = __kt0913_get_fm_frequency(radio, &f->frequency);
+
+	if (ret)
+		return ret;
+
+	/* convert kHz freq into v4l2 freq */
+	f->frequency = khz_to_v4l2_freq(f->frequency);
+
+	return 0;
+}
+
+static int kt0913_ioctl_vidioc_s_frequency(struct file *file, void *priv,
+					   const struct v4l2_frequency *f)
+{
+	struct kt0913_device *radio = video_drvdata(file);
+	unsigned int freq = f->frequency;
+	unsigned int new_band;
+	unsigned int half_gap_freq;
+	int ret;
+
+	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
+		return -EINVAL;
+
+	if (freq == 0)
+		return -EINVAL;
+
+	/* calculate the middle frequency on the gap of the bands */
+	half_gap_freq = kt0913_bands[BAND_AM].rangehigh;
+
+	if (kt0913_use_campus_band)
+		/* using the AM band and the campus FM band if enabled */
+		half_gap_freq += kt0913_bands[BAND_FM_CAMUS].rangelow;
+	else
+		/* or using the AM band and the standard FM band */
+		half_gap_freq += kt0913_bands[BAND_FM].rangelow;
+
+	half_gap_freq /= 2;
+
+	if (freq <= half_gap_freq)
+		new_band = BAND_AM;
+	else if (freq <= kt0913_bands[BAND_FM].rangelow &&
+		 kt0913_use_campus_band)
+		new_band = BAND_FM_CAMUS;
+	else
+		new_band = BAND_FM;
+
+	/* is the requested band different than the one currently set? */
+	if (radio->band != new_band) {
+		/* update the band on the device */
+		ret = __kt0913_set_am_fm_band(radio, new_band);
+		if (ret)
+			return ret;
+		radio->band = new_band;
+	}
+
+	/* clamp the frequency to the band boundaries */
+	freq = clamp(freq, kt0913_bands[new_band].rangelow,
+		     kt0913_bands[new_band].rangehigh);
+
+	/* convert v4l2 freq to kHz */
+	freq = v4l2_freq_to_khz(freq);
+
+	if (radio->band == BAND_AM)
+		return __kt0913_set_am_frequency(radio, freq);
+	else
+		return __kt0913_set_fm_frequency(radio, freq);
+}
+
+static int kt0913_ioctl_vidioc_enum_freq_bands(struct file *file, void *priv,
+					       struct v4l2_frequency_band *band)
+{
+	if (band->tuner != 0)
+		return -EINVAL;
+
+	switch (band->index) {
+	case 0:
+		if (kt0913_use_campus_band)
+			*band = kt0913_bands[BAND_FM_CAMUS];
+		else
+			*band = kt0913_bands[BAND_FM];
+		return 0;
+	case 1:
+		*band = kt0913_bands[BAND_AM];
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+/* ************************************************************************* */
+
+/* V4L2 vidioc */
+static int kt0913_ioctl_vidioc_querycap(struct file *file, void *priv,
+					struct v4l2_capability *capability)
+{
+	struct kt0913_device *radio = video_drvdata(file);
+	struct video_device *dev;
+
+	if (!radio)
+		return -ENODEV;
+
+	dev = &radio->vdev;
+
+	if (!dev)
+		return -ENODEV;
+
+	strscpy(capability->driver, KT0913_FM_AM_DRIVER_NAME,
+		sizeof(capability->driver));
+	strscpy(capability->card, dev->name, sizeof(capability->card));
+	snprintf(capability->bus_info, sizeof(capability->bus_info),
+		 "I2C:%s", dev_name(&dev->dev));
+	return 0;
+}
+
+static int kt0913_ioctl_vidioc_g_tuner(struct file *file, void *priv,
+				       struct v4l2_tuner *v)
+{
+	struct kt0913_device *radio = video_drvdata(file);
+	int ret;
+	int stereo_enabled;
+	int is_stereo;
+
+	if (v->index != 0)
+		return -EINVAL;
+
+	strscpy(v->name, "FM/AM", sizeof(v->name));
+	v->type = V4L2_TUNER_RADIO;
+
+	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
+		V4L2_TUNER_CAP_FREQ_BANDS;
+
+	v->rangelow = kt0913_bands[BAND_AM].rangelow;
+	v->rangehigh = kt0913_bands[BAND_FM].rangehigh;
+
+	if (radio->band == BAND_AM) {
+		v->rxsubchans = V4L2_TUNER_SUB_MONO;
+		v->audmode = V4L2_TUNER_MODE_MONO;
+
+		ret = __kt0913_get_am_rssi(radio, &v->signal);
+		if (ret)
+			return ret;
+	} else {
+		ret = __kt0913_get_cfg_stereo_enabled(radio, &stereo_enabled);
+		if (ret)
+			return ret;
+
+		v->rxsubchans = stereo_enabled ?
+			V4L2_TUNER_SUB_STEREO : V4L2_TUNER_SUB_MONO;
+
+		ret = __kt0913_get_rx_stereo_or_mono(radio, &is_stereo);
+		if (ret)
+			return ret;
+
+		v->audmode = is_stereo ?
+			V4L2_TUNER_MODE_STEREO : V4L2_TUNER_MODE_MONO;
+
+		ret = __kt0913_get_fm_rssi(radio, &v->signal);
+		if (ret)
+			return ret;
+	}
+
+	/* AFC is enabled and active by default */
+	v->afc = 1;
+
+	return 0;
+}
+
+static int kt0913_ioctl_vidioc_s_tuner(struct file *file, void *priv,
+				       const struct v4l2_tuner *v)
+{
+	struct kt0913_device *radio = video_drvdata(file);
+
+	if (v->index != 0)
+		return -EINVAL;
+
+	/* only mono and stereo are supported */
+	if (v->audmode != V4L2_TUNER_MODE_MONO &&
+	    v->audmode != V4L2_TUNER_MODE_STEREO)
+		return 0;
+
+	/* AM is mono only, so don't try to set it to stereo */
+	if (radio->band == BAND_AM && v->audmode != V4L2_TUNER_MODE_MONO)
+		return 0;
+
+	/* set to stereo if specified, otherwise set to mono */
+	return __kt0913_set_cfg_stereo_enabled(radio,
+		v->audmode == V4L2_TUNER_MODE_STEREO);
+}
+
+static int kt0913_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct kt0913_device *radio = v4l2_ctrl_to_device(ctrl);
+
+	switch (ctrl->id) {
+	case V4L2_CID_AUDIO_MUTE:
+		return __kt0913_set_mute(radio, ctrl->val);
+	case V4L2_CID_AUDIO_VOLUME:
+		return __kt0913_set_volume(radio, ctrl->val);
+	case V4L2_CID_GAIN:
+		return __kt0913_set_au_gain(radio, ctrl->val);
+	case V4L2_CID_TUNE_DEEMPHASIS:
+		return __kt0913_set_deemphasis(radio, ctrl->val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int kt0913_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct kt0913_device *radio = v4l2_ctrl_to_device(ctrl);
+
+	switch (ctrl->id) {
+	case V4L2_CID_RF_TUNER_PLL_LOCK:
+		return __kt0913_get_pll_status(radio, &ctrl->val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct v4l2_ctrl_ops kt0913_ctrl_ops = {
+	.s_ctrl = kt0913_s_ctrl,
+	.g_volatile_ctrl = kt0913_g_volatile_ctrl,
+};
+
+/* ************************************************************************* */
+
+/* File system interface (use the ancillary fops for v4l2) */
+static const struct v4l2_file_operations kt0913_radio_fops = {
+	.owner = THIS_MODULE,
+	.open = v4l2_fh_open,
+	.release = v4l2_fh_release,
+	.poll = v4l2_ctrl_poll,
+	.unlocked_ioctl = video_ioctl2,
+};
+
+/* ioctl ops */
+static const struct v4l2_ioctl_ops kt0913_ioctl_ops = {
+	.vidioc_querycap = kt0913_ioctl_vidioc_querycap,
+	.vidioc_g_tuner = kt0913_ioctl_vidioc_g_tuner,
+	.vidioc_s_tuner = kt0913_ioctl_vidioc_s_tuner,
+	.vidioc_g_frequency = kt0913_ioctl_vidioc_g_frequency,
+	.vidioc_s_frequency = kt0913_ioctl_vidioc_s_frequency,
+	.vidioc_enum_freq_bands = kt0913_ioctl_vidioc_enum_freq_bands,
+	/* use ancillary functions for these: */
+	.vidioc_log_status = v4l2_ctrl_log_status,
+	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
+	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
+};
+
+/* V4L2 RADIO device structure */
+static struct video_device kt0913_radio_template = {
+	.name = KT0913_FM_AM_DRIVER_NAME,
+	.fops = &kt0913_radio_fops,
+	.ioctl_ops = &kt0913_ioctl_ops,
+	.release = video_device_release_empty,
+	.vfl_dir = VFL_DIR_RX,
+	.device_caps = V4L2_CAP_TUNER | V4L2_CAP_RADIO,
+};
+
+/* ************************************************************************* */
+
+#if IS_ENABLED(CONFIG_OF)
+static const struct of_device_id kt0913_of_match[] = {
+	{ .compatible = "ktm,kt0913" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, kt0913_of_match);
+#endif /* IS_ENABLED(CONFIG_OF) */
+
+static void __kt0913_parse_dt(struct kt0913_device *radio)
+{
+	const void *ptr_anti_pop = of_get_property(radio->client->dev.of_node,
+		"ktm,anti-pop", NULL);
+	const void *ptr_refclk = of_get_property(radio->client->dev.of_node,
+		"ktm,refclk", NULL);
+
+	if (ptr_anti_pop) {
+		radio->audio_anti_pop =
+			clamp(be32_to_cpup(ptr_anti_pop), 0U, 3U);
+	} else {
+		radio->audio_anti_pop = 0;
+		v4l2_warn(radio->client,
+			  "No ktm,anti-pop on dt node, using default");
+	}
+
+	if (ptr_refclk) {
+		radio->refclock_val =
+			clamp(be32_to_cpup(ptr_refclk), 0U, 9U);
+	} else {
+		radio->refclock_val = 0;
+		v4l2_warn(radio->client,
+			  "No ktm,refclk on dt node, using default");
+	}
+}
+
+/* ************************************************************************* */
+
+static int kt0913_probe(struct i2c_client *client,
+			const struct i2c_device_id *id)
+{
+	struct kt0913_device *radio;
+	struct v4l2_device *v4l2_dev;
+	struct v4l2_ctrl_handler *hdl;
+	struct regmap *regmap;
+	int ret;
+
+	pr_debug("%s\n", __func__);
+
+	/* this driver uses word R/W i2c operations, check if it's supported */
+	ret = i2c_check_functionality(client->adapter,
+				      I2C_FUNC_SMBUS_READ_WORD_DATA |
+				      I2C_FUNC_SMBUS_WRITE_WORD_DATA);
+	if (!ret) {
+		v4l2_err(client,
+			 "I2C adapter doesn't support word operations");
+		return -EIO;
+	}
+
+	/* check if the device exist on the bus before initializing it */
+	ret = i2c_smbus_read_word_data(client, KT0913_REG_CHIP_ID);
+	if (ret < 0) {
+		v4l2_err(client,
+			 "Error reading CHIP ID of the kt0913 (%d)", ret);
+		return ret;
+	}
+
+	/* check if the CHIP ID register value matches the expected value */
+	if (ret != KT0913_CHIP_ID) {
+		v4l2_err(radio->client,
+			 "Invalid CHIP ID: 0x%x, expected 0x%x",
+			 ret, KT0913_CHIP_ID);
+		return -ENODEV;
+	}
+
+	v4l2_info(client,
+		  "kt0913 found @ 0x%x (%s)\n",
+		  client->addr, client->adapter->name);
+
+	/* alloc context for the kt0913 radio struct */
+	radio = devm_kzalloc(&client->dev, sizeof(*radio), GFP_KERNEL);
+	if (!radio)
+		return -ENOMEM;
+
+	v4l2_dev = &radio->v4l2_dev;
+	ret = v4l2_device_register(&client->dev, v4l2_dev);
+	if (ret < 0) {
+		v4l2_err(client,
+			 "could not register v4l2_dev\n");
+		goto errfr;
+	}
+
+	mutex_init(&radio->mutex);
+
+	/* register the control handler from the context struct */
+	hdl = &radio->ctrl_handler;
+	v4l2_ctrl_handler_init(hdl, 5);
+
+	/* add the control: Mute */
+	radio->ctrl_mute = v4l2_ctrl_new_std(hdl, &kt0913_ctrl_ops,
+					     V4L2_CID_AUDIO_MUTE,
+					     0, 1, 1, 0);
+	if (hdl->error) {
+		ret = hdl->error;
+		v4l2_err(v4l2_dev, "Could not register control: mute\n");
+		goto errunreg;
+	}
+
+	/* add the control: Volume */
+	radio->ctrl_volume = v4l2_ctrl_new_std(hdl, &kt0913_ctrl_ops,
+					       V4L2_CID_AUDIO_VOLUME,
+					       -60, 0, 2, 0);
+	if (hdl->error) {
+		ret = hdl->error;
+		v4l2_err(v4l2_dev, "Could not register control: Volume\n");
+		goto errunreg;
+	}
+
+	/* add the control: audio gain */
+	radio->ctrl_au_gain = v4l2_ctrl_new_std(hdl, &kt0913_ctrl_ops,
+						V4L2_CID_GAIN,
+						-3, 6, 3, 3);
+	if (hdl->error) {
+		ret = hdl->error;
+		v4l2_err(v4l2_dev, "Could not register control: audio gain\n");
+		goto errunreg;
+	}
+	radio->ctrl_au_gain->flags |= V4L2_CTRL_FLAG_SLIDER;
+
+	/* add the control: PLL Lock */
+	radio->ctrl_pll_lock = v4l2_ctrl_new_std(hdl, &kt0913_ctrl_ops,
+						 V4L2_CID_RF_TUNER_PLL_LOCK,
+						 0, 1, 1, 0);
+	if (hdl->error) {
+		ret = hdl->error;
+		v4l2_err(v4l2_dev, "Could not register control: pll lock\n");
+		goto errunreg;
+	}
+	radio->ctrl_pll_lock->flags |= (V4L2_CTRL_FLAG_VOLATILE |
+		V4L2_CTRL_FLAG_READ_ONLY);
+
+	/* add the control: deemphasis */
+	radio->ctrl_deemp = v4l2_ctrl_new_std_menu(hdl, &kt0913_ctrl_ops,
+						   V4L2_CID_TUNE_DEEMPHASIS,
+						   V4L2_DEEMPHASIS_75_uS,
+						   0,
+						   V4L2_DEEMPHASIS_75_uS);
+	if (hdl->error) {
+		ret = hdl->error;
+		v4l2_err(v4l2_dev, "Could not register control: deemphasis\n");
+		goto errunreg;
+	}
+	/* the control handler is ready to be used */
+	v4l2_dev->ctrl_handler = hdl;
+
+	radio->vdev = kt0913_radio_template;
+	radio->vdev.lock = &radio->mutex;
+	radio->vdev.v4l2_dev = v4l2_dev;
+	video_set_drvdata(&radio->vdev, radio);
+
+	radio->client = client;
+	i2c_set_clientdata(client, radio);
+
+	/* init the regmap of the kt0913 */
+	regmap = devm_regmap_init_i2c(client, &kt0913_regmap_config);
+	if (IS_ERR(regmap)) {
+		ret = PTR_ERR(regmap);
+		v4l2_err(client,
+			 "devm_regmap_init_i2c() failed! %d", ret);
+		goto errunreg;
+	}
+	radio->regmap = regmap;
+
+	__kt0913_parse_dt(radio);
+
+	/* init the kt0913 into a known state */
+	ret = __kt0913_init(radio);
+	if (ret) {
+		v4l2_err(client,
+			 "__kt0913_init() failed! %d", ret);
+		goto errunreg;
+	}
+
+	pm_runtime_get_noresume(&client->dev);
+	pm_runtime_set_active(&client->dev);
+	pm_runtime_enable(&client->dev);
+	pm_runtime_dont_use_autosuspend(&client->dev);
+
+	ret = video_register_device(&radio->vdev,
+				    VFL_TYPE_RADIO, kt0913_v4l2_radio_nr);
+	if (ret < 0) {
+		v4l2_err(client,
+			 "Could not register video device!");
+		goto error_pm_disable;
+	}
+
+	v4l2_info(client, "registered.");
+	return 0;
+error_pm_disable:
+	pm_runtime_disable(&client->dev);
+	pm_runtime_set_suspended(&client->dev);
+errunreg:
+	v4l2_ctrl_handler_free(hdl);
+	v4l2_device_unregister(v4l2_dev);
+errfr:
+	__kt0913_set_standby(radio, true);
+	kfree(radio);
+	return ret;
+}
+
+static int kt0913_remove(struct i2c_client *client)
+{
+	struct kt0913_device *radio = i2c_get_clientdata(client);
+
+	pr_debug("%s\n", __func__);
+	if (!radio)
+		return -EINVAL;
+
+	__kt0913_set_standby(radio, true);
+
+	pm_runtime_get_sync(&client->dev);
+	pm_runtime_disable(&client->dev);
+	pm_runtime_set_suspended(&client->dev);
+	pm_runtime_put_noidle(&client->dev);
+
+	video_unregister_device(&radio->vdev);
+	v4l2_ctrl_handler_free(&radio->ctrl_handler);
+	v4l2_device_unregister(&radio->v4l2_dev);
+
+	v4l2_info(client, "removed.");
+	return 0;
+}
+
+/* ************************************************************************* */
+
+#ifdef CONFIG_PM
+static int kt0913_i2c_pm_runtime_suspend(struct device *dev)
+{
+	struct kt0913_device *radio = i2c_get_clientdata(to_i2c_client(dev));
+
+	pr_debug("%s\n", __func__);
+	if (!radio)
+		return 0;
+
+	return __kt0913_set_standby(radio, true);
+}
+
+static int kt0913_i2c_pm_runtime_resume(struct device *dev)
+{
+	struct kt0913_device *radio = i2c_get_clientdata(to_i2c_client(dev));
+
+	pr_debug("%s\n", __func__);
+	if (!radio)
+		return 0;
+
+	return __kt0913_set_standby(radio, false);
+}
+#endif /* CONFIG_PM */
+
+static const struct dev_pm_ops kt0913_i2c_pm_ops = {
+	SET_RUNTIME_PM_OPS(kt0913_i2c_pm_runtime_suspend,
+			   kt0913_i2c_pm_runtime_resume, NULL)
+};
+
+static const struct i2c_device_id kt0913_idtable[] = {
+	{ "kt0913", 0 },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, kt0913_idtable);
+
+static struct i2c_driver kt0913_driver = {
+	.driver = {
+		.name = "kt0913",
+		.of_match_table = of_match_ptr(kt0913_of_match),
+		.pm = &kt0913_i2c_pm_ops,
+	},
+	.probe = kt0913_probe,
+	.remove = kt0913_remove,
+	.id_table = kt0913_idtable,
+};
+module_i2c_driver(kt0913_driver);
+
+MODULE_AUTHOR("Santiago Hormazabal <santiagohssl@gmail.com>");
+MODULE_DESCRIPTION("KTMicro KT0913 AM/FM receiver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.0.2");
+
+module_param(kt0913_use_campus_band, int, 0);
+MODULE_PARM_DESC(kt0913_use_campus_band, "Use the Campus Band feature (FM range 32MHz-110MHz)");
+module_param(kt0913_v4l2_radio_nr, int, 0);
+MODULE_PARM_DESC(kt0913_v4l2_radio_nr, "v4l2 device number to use (i.e. /dev/radioX)");