x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.

The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:

<__hrtimer_run_queues+249>:  nopl   0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>:  mov    %r14,%rdi
<__hrtimer_run_queues+257>:  cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>:  mov    %eax,%r12d
<__hrtimer_run_queues+266>:  xchg   %ax,%ax
<__hrtimer_run_queues+268>:  mov    %r13,%rdi

Which triggers this crash:

  BUG: unable to handle page fault for address: 00000000000f41c9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: 0002 [#1] SMP NOPTI
  CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
  RIP: 0010:__hrtimer_run_queues+0x106/0x230

Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.

The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.

During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.

Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.

[ mingo: Refined the changelog ]

Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

6 files changed, 1557 insertions, 0 deletions

diff --git a/drivers/iio/amplifiers/Kconfig b/drivers/iio/amplifiers/Kconfig
new file mode 100644
index 000000000..9e24421b5
--- /dev/null
+++ b/drivers/iio/amplifiers/Kconfig
@@ -0,0 +1,69 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Gain Amplifiers, etc.
+#
+# When adding new entries keep the list in alphabetical order
+
+menu "Amplifiers"
+
+config AD8366
+	tristate "Analog Devices AD8366 and similar Gain Amplifiers"
+	depends on SPI
+	depends on GPIOLIB
+	select BITREVERSE
+	help
+	  Say yes here to build support for Analog Devices AD8366 and similar
+	  gain amplifiers. This driver supports the following gain amplifiers
+	  from Analog Devices:
+	    AD8366 Dual-Digital Variable Gain Amplifier (VGA)
+	    ADA4961 BiCMOS RF Digital Gain Amplifier (DGA)
+	    ADL5240 Digitally controlled variable gain amplifier (VGA)
+	    ADRF5702: 0.125 dB LSB, 8-Bit, Silicon Digital Attenuator
+	    ADRF5703: 0.25 dB LSB, 7-Bit, Silicon Digital Attenuator
+	    ADRF5720: 0.5 dB LSB, 6-Bit, Silicon Digital Attenuator
+	    ADRF5730: 0.5 dB LSB, 6-Bit, Silicon Digital Attenuator
+	    ADRF5731: 2 dB LSB, 4-Bit, Silicon Digital Attenuator
+	    HMC271A: 1dB LSB 5-Bit Digital Attenuator SMT
+	    HMC792A 0.25 dB LSB GaAs MMIC 6-Bit Digital Attenuator
+	    HMC1018A: 1.0 dB LSB GaAs MMIC 5-BIT Digital Attenuator
+	    HMC1019A: 0.5 dB LSB GaAs MMIC 5-BIT Digital Attenuator
+	    HMC1119 0.25 dB LSB, 7-Bit, Silicon Digital Attenuator
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad8366.
+
+config ADA4250
+	tristate "Analog Devices ADA4250 Instrumentation Amplifier"
+	depends on SPI
+	select REGMAP_SPI
+	help
+	  Say yes here to build support for Analog Devices ADA4250
+	  SPI Amplifier's support. The driver provides direct access via
+	  sysfs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ada4250.
+
+config ADL8113
+	tristate "Analog Devices ADL8113 Low Noise Amplifier"
+	depends on GPIOLIB
+	help
+	  Say yes here to build support for Analog Devices ADL8113 Low Noise
+	  Amplifier with integrated bypass switches. The device supports four
+	  operation modes controlled by GPIO pins: internal amplifier,
+	  internal bypass, and two external bypass modes.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called adl8113.
+
+config HMC425
+	tristate "Analog Devices HMC425A and similar GPIO Gain Amplifiers"
+	depends on GPIOLIB
+	help
+	  Say yes here to build support for Analog Devices HMC425A and similar
+	  gain amplifiers or step attenuators.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hmc425a.
+
+endmenu
diff --git a/drivers/iio/amplifiers/Makefile b/drivers/iio/amplifiers/Makefile
new file mode 100644
index 000000000..0a76443be
--- /dev/null
+++ b/drivers/iio/amplifiers/Makefile
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile iio/amplifiers
+#
+
+# When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_AD8366) += ad8366.o
+obj-$(CONFIG_ADA4250) += ada4250.o
+obj-$(CONFIG_ADL8113) += adl8113.o
+obj-$(CONFIG_HMC425) += hmc425a.o
diff --git a/drivers/iio/amplifiers/ad8366.c b/drivers/iio/amplifiers/ad8366.c
new file mode 100644
index 000000000..e12f8604f
--- /dev/null
+++ b/drivers/iio/amplifiers/ad8366.c
@@ -0,0 +1,402 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AD8366 and similar Gain Amplifiers
+ * This driver supports the following gain amplifiers:
+ *   AD8366 Dual-Digital Variable Gain Amplifier (VGA)
+ *   ADA4961 BiCMOS RF Digital Gain Amplifier (DGA)
+ *   ADL5240 Digitally controlled variable gain amplifier (VGA)
+ *   ADRF5702: 0.125 dB LSB, 8-Bit, Silicon Digital Attenuator, 50 MHz to 20 GHz
+ *   ADRF5703: 0.25 dB LSB, 7-Bit, Silicon Digital Attenuator, 9 kHz to 20 GHz
+ *   ADRF5720: 0.5 dB LSB, 6-Bit, Silicon Digital Attenuator, 9 kHz to 40 GHz
+ *   ADRF5730: 0.5 dB LSB, 6-Bit, Silicon Digital Attenuator, 100 MHz to 40 GHz
+ *   ADRF5731: 2 dB LSB, 4-Bit, Silicon Digital Attenuator, 100 MHz to 40 GHz
+ *   HMC271A: 1dB LSB 5-Bit Digital Attenuator SMT, 0.7 - 3.7 GHz
+ *   HMC792A 0.25 dB LSB GaAs MMIC 6-Bit Digital Attenuator
+ *   HMC1018A: 1.0 dB LSB GaAs MMIC 5-BIT DIGITAL ATTENUATOR, 0.1 - 30 GHz
+ *   HMC1019A: 0.5 dB LSB GaAs MMIC 5-BIT DIGITAL ATTENUATOR, 0.1 - 30 GHz
+ *   HMC1119 0.25 dB LSB, 7-Bit, Silicon Digital Attenuator
+ *
+ * Copyright 2012-2026 Analog Devices Inc.
+ */
+
+#include <linux/bitrev.h>
+#include <linux/bits.h>
+#include <linux/dev_printk.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/math.h>
+#include <linux/minmax.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+#include <linux/spi/spi.h>
+#include <linux/types.h>
+#include <linux/unaligned.h>
+
+#include <linux/iio/iio.h>
+
+struct ad8366_info {
+	const char *name;
+	int gain_min;
+	int gain_max;
+	int gain_step;
+	size_t num_channels;
+	size_t (*pack_code)(const unsigned char *code, size_t num_channels,
+			    unsigned char *data);
+};
+
+struct ad8366_state {
+	struct spi_device	*spi;
+	struct mutex            lock; /* protect sensor state */
+	unsigned char		ch[2];
+	const struct ad8366_info *info;
+	/*
+	 * DMA (thus cache coherency maintenance) may require the
+	 * transfer buffers to live in their own cache lines.
+	 */
+	unsigned char		data[2] __aligned(IIO_DMA_MINALIGN);
+};
+
+static size_t ad8366_pack_code(const unsigned char *code, size_t num_channels,
+			       unsigned char *data)
+{
+	u8 ch_a = bitrev8(code[0]) >> 2;
+	u8 ch_b = bitrev8(code[1]) >> 2;
+
+	put_unaligned_be16((ch_b << 6) | ch_a, &data[0]);
+	return sizeof(__be16);
+}
+
+static size_t adrf5731_pack_code(const unsigned char *code, size_t num_channels,
+				 unsigned char *data)
+{
+	data[0] = code[0] << 2;
+	return 1;
+}
+
+static size_t hmc271_pack_code(const unsigned char *code, size_t num_channels,
+			       unsigned char *data)
+{
+	data[0] = bitrev8(code[0]) >> 3;
+	return 1;
+}
+
+static const struct ad8366_info ad8366_chip_info = {
+	.name = "ad8366",
+	.gain_min = 4500,
+	.gain_max = 20500,
+	.gain_step = 253,
+	.num_channels = 2,
+	.pack_code = ad8366_pack_code,
+};
+
+static const struct ad8366_info ada4961_chip_info = {
+	.name = "ada4961",
+	.gain_min = -6000,
+	.gain_max = 15000,
+	.gain_step = -1000,
+	.num_channels = 1,
+};
+
+static const struct ad8366_info adl5240_chip_info = {
+	.name = "adl5240",
+	.gain_min = -11500,
+	.gain_max = 20000,
+	.gain_step = 500,
+	.num_channels = 1,
+};
+
+static const struct ad8366_info adrf5702_chip_info = {
+	.name = "adrf5702",
+	.gain_min = -31875,
+	.gain_max = 0,
+	.gain_step = -125,
+	.num_channels = 1,
+};
+
+static const struct ad8366_info adrf5703_chip_info = {
+	.name = "adrf5703",
+	.gain_min = -31750,
+	.gain_max = 0,
+	.gain_step = -250,
+	.num_channels = 1,
+};
+
+static const struct ad8366_info adrf5720_chip_info = {
+	.name = "adrf5720",
+	.gain_min = -31500,
+	.gain_max = 0,
+	.gain_step = -500,
+	.num_channels = 1,
+};
+
+static const struct ad8366_info adrf5730_chip_info = {
+	.name = "adrf5730",
+	.gain_min = -31500,
+	.gain_max = 0,
+	.gain_step = -500,
+	.num_channels = 1,
+};
+
+static const struct ad8366_info adrf5731_chip_info = {
+	.name = "adrf5731",
+	.gain_min = -30000,
+	.gain_max = 0,
+	.gain_step = -2000,
+	.num_channels = 1,
+	.pack_code = adrf5731_pack_code,
+};
+
+static const struct ad8366_info hmc271_chip_info = {
+	.name = "hmc271a",
+	.gain_min = -31000,
+	.gain_max = 0,
+	.gain_step = 1000,
+	.num_channels = 1,
+	.pack_code = hmc271_pack_code,
+};
+
+static const struct ad8366_info hmc792_chip_info = {
+	.name = "hmc792a",
+	.gain_min = -15750,
+	.gain_max = 0,
+	.gain_step = 250,
+	.num_channels = 1,
+};
+
+static const struct ad8366_info hmc1018_chip_info = {
+	.name = "hmc1018a",
+	.gain_min = -31000,
+	.gain_max = 0,
+	.gain_step = 1000,
+	.num_channels = 1,
+};
+
+static const struct ad8366_info hmc1019_chip_info = {
+	.name = "hmc1019a",
+	.gain_min = -15500,
+	.gain_max = 0,
+	.gain_step = 500,
+	.num_channels = 1,
+};
+
+static const struct ad8366_info hmc1119_chip_info = {
+	.name = "hmc1119",
+	.gain_min = -31750,
+	.gain_max = 0,
+	.gain_step = -250,
+	.num_channels = 1,
+};
+
+static int ad8366_write_code(struct ad8366_state *st)
+{
+	const struct ad8366_info *inf = st->info;
+	size_t len = 1;
+
+	if (inf->pack_code)
+		len = inf->pack_code(st->ch, inf->num_channels, st->data);
+	else
+		st->data[0] = st->ch[0];
+
+	return spi_write(st->spi, st->data, len);
+}
+
+static int ad8366_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val,
+			   int *val2,
+			   long m)
+{
+	struct ad8366_state *st = iio_priv(indio_dev);
+	const struct ad8366_info *inf = st->info;
+	int ret;
+	int code, gain = 0;
+
+	mutex_lock(&st->lock);
+	switch (m) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		code = st->ch[chan->channel];
+		gain = inf->gain_step > 0 ? inf->gain_min : inf->gain_max;
+		gain += inf->gain_step * code;
+		/* Values in dB */
+		*val = gain / 1000;
+		*val2 = (gain % 1000) * 1000;
+
+		ret = IIO_VAL_INT_PLUS_MICRO_DB;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	mutex_unlock(&st->lock);
+
+	return ret;
+};
+
+static int ad8366_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int val,
+			    int val2,
+			    long mask)
+{
+	struct ad8366_state *st = iio_priv(indio_dev);
+	const struct ad8366_info *inf = st->info;
+	int code = 0, gain;
+	int ret;
+
+	/* Values in dB */
+	if (val < 0)
+		gain = (val * 1000) - (val2 / 1000);
+	else
+		gain = (val * 1000) + (val2 / 1000);
+
+	if (gain > inf->gain_max || gain < inf->gain_min)
+		return -EINVAL;
+
+	gain -= inf->gain_step > 0 ? inf->gain_min : inf->gain_max;
+	code = DIV_ROUND_CLOSEST(gain, inf->gain_step);
+
+	mutex_lock(&st->lock);
+	switch (mask) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		st->ch[chan->channel] = code;
+		ret = ad8366_write_code(st);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int ad8366_write_raw_get_fmt(struct iio_dev *indio_dev,
+				    struct iio_chan_spec const *chan,
+				    long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		return IIO_VAL_INT_PLUS_MICRO_DB;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info ad8366_info = {
+	.read_raw = &ad8366_read_raw,
+	.write_raw = &ad8366_write_raw,
+	.write_raw_get_fmt = &ad8366_write_raw_get_fmt,
+};
+
+#define AD8366_CHAN(_channel) {				\
+	.type = IIO_VOLTAGE,				\
+	.output = 1,					\
+	.indexed = 1,					\
+	.channel = _channel,				\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN),\
+}
+
+static const struct iio_chan_spec ad8366_channels[] = {
+	AD8366_CHAN(0),
+	AD8366_CHAN(1),
+};
+
+static int ad8366_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct gpio_desc *enable_gpio;
+	struct reset_control *rstc;
+	struct iio_dev *indio_dev;
+	struct ad8366_state *st;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+	if (indio_dev == NULL)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+
+	ret = devm_mutex_init(dev, &st->lock);
+	if (ret)
+		return ret;
+
+	ret = devm_regulator_get_enable(dev, "vcc");
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to get regulator\n");
+
+	st->spi = spi;
+	st->info = spi_get_device_match_data(spi);
+
+	enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_HIGH);
+	if (IS_ERR(enable_gpio))
+		return dev_err_probe(dev, PTR_ERR(enable_gpio),
+				     "Failed to get enable GPIO\n");
+
+	rstc = devm_reset_control_get_optional_exclusive_deasserted(dev, NULL);
+	if (IS_ERR(rstc))
+		return dev_err_probe(dev, PTR_ERR(rstc),
+				     "Failed to get reset controller\n");
+
+	indio_dev->name = st->info->name;
+	indio_dev->info = &ad8366_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = ad8366_channels;
+	indio_dev->num_channels = st->info->num_channels;
+
+	ret = ad8366_write_code(st);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "failed to write initial gain\n");
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct spi_device_id ad8366_id[] = {
+	{ .name = "ad8366", .driver_data = (kernel_ulong_t)&ad8366_chip_info },
+	{ .name = "ada4961", .driver_data = (kernel_ulong_t)&ada4961_chip_info },
+	{ .name = "adl5240", .driver_data = (kernel_ulong_t)&adl5240_chip_info },
+	{ .name = "adrf5702", .driver_data = (kernel_ulong_t)&adrf5702_chip_info },
+	{ .name = "adrf5703", .driver_data = (kernel_ulong_t)&adrf5703_chip_info },
+	{ .name = "adrf5720", .driver_data = (kernel_ulong_t)&adrf5720_chip_info },
+	{ .name = "adrf5730", .driver_data = (kernel_ulong_t)&adrf5730_chip_info },
+	{ .name = "adrf5731", .driver_data = (kernel_ulong_t)&adrf5731_chip_info },
+	{ .name = "hmc271a", .driver_data = (kernel_ulong_t)&hmc271_chip_info },
+	{ .name = "hmc792a", .driver_data = (kernel_ulong_t)&hmc792_chip_info },
+	{ .name = "hmc1018a", .driver_data = (kernel_ulong_t)&hmc1018_chip_info },
+	{ .name = "hmc1019a", .driver_data = (kernel_ulong_t)&hmc1019_chip_info },
+	{ .name = "hmc1119", .driver_data = (kernel_ulong_t)&hmc1119_chip_info },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, ad8366_id);
+
+static const struct of_device_id ad8366_of_match[] = {
+	{ .compatible = "adi,ad8366", .data = &ad8366_chip_info },
+	{ .compatible = "adi,ada4961", .data = &ada4961_chip_info },
+	{ .compatible = "adi,adl5240", .data = &adl5240_chip_info },
+	{ .compatible = "adi,adrf5702", .data = &adrf5702_chip_info },
+	{ .compatible = "adi,adrf5703", .data = &adrf5703_chip_info },
+	{ .compatible = "adi,adrf5720", .data = &adrf5720_chip_info },
+	{ .compatible = "adi,adrf5730", .data = &adrf5730_chip_info },
+	{ .compatible = "adi,adrf5731", .data = &adrf5731_chip_info },
+	{ .compatible = "adi,hmc271a", .data = &hmc271_chip_info },
+	{ .compatible = "adi,hmc792a", .data = &hmc792_chip_info },
+	{ .compatible = "adi,hmc1018a", .data = &hmc1018_chip_info },
+	{ .compatible = "adi,hmc1019a", .data = &hmc1019_chip_info },
+	{ .compatible = "adi,hmc1119", .data = &hmc1119_chip_info },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ad8366_of_match);
+
+static struct spi_driver ad8366_driver = {
+	.driver = {
+		.name		= KBUILD_MODNAME,
+		.of_match_table	= ad8366_of_match,
+	},
+	.probe		= ad8366_probe,
+	.id_table	= ad8366_id,
+};
+
+module_spi_driver(ad8366_driver);
+
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD8366 and similar Gain Amplifiers");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/amplifiers/ada4250.c b/drivers/iio/amplifiers/ada4250.c
new file mode 100644
index 000000000..9702de3a5
--- /dev/null
+++ b/drivers/iio/amplifiers/ada4250.c
@@ -0,0 +1,384 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ADA4250 driver
+ *
+ * Copyright 2022 Analog Devices Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/device.h>
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/types.h>
+#include <linux/units.h>
+
+/* ADA4250 Register Map */
+#define ADA4250_REG_GAIN_MUX        0x00
+#define ADA4250_REG_REFBUF_EN       0x01
+#define ADA4250_REG_RESET           0x02
+#define ADA4250_REG_SNSR_CAL_VAL    0x04
+#define ADA4250_REG_SNSR_CAL_CNFG   0x05
+#define ADA4250_REG_DIE_REV         0x18
+#define ADA4250_REG_CHIP_ID         0x19
+
+/* ADA4250_REG_GAIN_MUX Map */
+#define ADA4250_GAIN_MUX_MSK        GENMASK(2, 0)
+
+/* ADA4250_REG_REFBUF Map */
+#define ADA4250_REFBUF_MSK          BIT(0)
+
+/* ADA4250_REG_RESET Map */
+#define ADA4250_RESET_MSK           BIT(0)
+
+/* ADA4250_REG_SNSR_CAL_VAL Map */
+#define ADA4250_CAL_CFG_BIAS_MSK    GENMASK(7, 0)
+
+/* ADA4250_REG_SNSR_CAL_CNFG Bit Definition */
+#define ADA4250_BIAS_SET_MSK        GENMASK(3, 2)
+#define ADA4250_RANGE_SET_MSK       GENMASK(1, 0)
+
+/* Miscellaneous definitions */
+#define ADA4250_CHIP_ID             0x4250
+#define ADA4250_RANGE1              0
+#define	ADA4250_RANGE4              3
+
+/* ADA4250 current bias set */
+enum ada4250_current_bias {
+	ADA4250_BIAS_DISABLED,
+	ADA4250_BIAS_BANDGAP,
+	ADA4250_BIAS_AVDD,
+};
+
+struct ada4250_state {
+	struct spi_device	*spi;
+	struct regmap		*regmap;
+	/* Protect against concurrent accesses to the device and data content */
+	struct mutex		lock;
+	int			avdd_uv;
+	int			offset_uv;
+	u8			bias;
+	u8			gain;
+	bool			refbuf_en;
+	__le16			reg_val_16 __aligned(IIO_DMA_MINALIGN);
+};
+
+/* ADA4250 Current Bias Source Settings: Disabled, Bandgap Reference, AVDD */
+static const int calibbias_table[] = {0, 1, 2};
+
+/* ADA4250 Gain (V/V) values: 1, 2, 4, 8, 16, 32, 64, 128 */
+static const int hwgain_table[] = {1, 2, 4, 8, 16, 32, 64, 128};
+
+static const struct regmap_config ada4250_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.read_flag_mask = BIT(7),
+	.max_register = 0x1A,
+};
+
+static int ada4250_set_offset_uv(struct iio_dev *indio_dev,
+				 const struct iio_chan_spec *chan,
+				 int offset_uv)
+{
+	struct ada4250_state *st = iio_priv(indio_dev);
+
+	int i, ret, x[8], max_vos, min_vos, voltage_v, vlsb = 0;
+	u8 offset_raw, range = ADA4250_RANGE1;
+	u32 lsb_coeff[6] = {1333, 2301, 4283, 8289, 16311, 31599};
+
+	if (st->bias == 0 || st->bias == 3)
+		return -EINVAL;
+
+	voltage_v = DIV_ROUND_CLOSEST(st->avdd_uv, MICRO);
+
+	if (st->bias == ADA4250_BIAS_AVDD)
+		x[0] = voltage_v;
+	else
+		x[0] = 5;
+
+	x[1] = 126 * (x[0] - 1);
+
+	for (i = 0; i < 6; i++)
+		x[i + 2] = DIV_ROUND_CLOSEST(x[1] * 1000, lsb_coeff[i]);
+
+	if (st->gain == 0)
+		return -EINVAL;
+
+	/*
+	 * Compute Range and Voltage per LSB for the Sensor Offset Calibration
+	 * Example of computation for Range 1 and Range 2 (Current Bias Set = AVDD):
+	 *                     Range 1                            Range 2
+	 *   Gain   | Max Vos(mV) |   LSB(mV)        |  Max Vos(mV)  | LSB(mV) |
+	 *    2     |    X1*127   | X1=0.126(AVDD-1) |   X1*3*127    |  X1*3   |
+	 *    4     |    X2*127   | X2=X1/1.3333     |   X2*3*127    |  X2*3   |
+	 *    8     |    X3*127   | X3=X1/2.301      |   X3*3*127    |  X3*3   |
+	 *    16    |    X4*127   | X4=X1/4.283      |   X4*3*127    |  X4*3   |
+	 *    32    |    X5*127   | X5=X1/8.289      |   X5*3*127    |  X5*3   |
+	 *    64    |    X6*127   | X6=X1/16.311     |   X6*3*127    |  X6*3   |
+	 *    128   |    X7*127   | X7=X1/31.599     |   X7*3*127    |  X7*3   |
+	 */
+	for (i = ADA4250_RANGE1; i <= ADA4250_RANGE4; i++) {
+		max_vos = x[st->gain] *  127 * ((1 << (i + 1)) - 1);
+		min_vos = -1 * max_vos;
+		if (offset_uv > min_vos && offset_uv < max_vos) {
+			range = i;
+			vlsb = x[st->gain] * ((1 << (i + 1)) - 1);
+			break;
+		}
+	}
+
+	if (vlsb <= 0)
+		return -EINVAL;
+
+	offset_raw = DIV_ROUND_CLOSEST(abs(offset_uv), vlsb);
+
+	mutex_lock(&st->lock);
+	ret = regmap_update_bits(st->regmap, ADA4250_REG_SNSR_CAL_CNFG,
+				 ADA4250_RANGE_SET_MSK,
+				 FIELD_PREP(ADA4250_RANGE_SET_MSK, range));
+	if (ret)
+		goto exit;
+
+	st->offset_uv = offset_raw * vlsb;
+
+	/*
+	 * To set the offset calibration value, use bits [6:0] and bit 7 as the
+	 * polarity bit (set to "0" for a negative offset and "1" for a positive
+	 * offset).
+	 */
+	if (offset_uv < 0) {
+		offset_raw |= BIT(7);
+		st->offset_uv *= (-1);
+	}
+
+	ret = regmap_write(st->regmap, ADA4250_REG_SNSR_CAL_VAL, offset_raw);
+
+exit:
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int ada4250_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long info)
+{
+	struct ada4250_state *st = iio_priv(indio_dev);
+	int ret;
+
+	switch (info) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		ret = regmap_read(st->regmap, ADA4250_REG_GAIN_MUX, val);
+		if (ret)
+			return ret;
+
+		*val = BIT(*val);
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_OFFSET:
+		*val = st->offset_uv;
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_CALIBBIAS:
+		ret = regmap_read(st->regmap, ADA4250_REG_SNSR_CAL_CNFG, val);
+		if (ret)
+			return ret;
+
+		*val = FIELD_GET(ADA4250_BIAS_SET_MSK, *val);
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 1;
+		*val2 = 1000000;
+
+		return IIO_VAL_FRACTIONAL;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ada4250_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int val, int val2, long info)
+{
+	struct ada4250_state *st = iio_priv(indio_dev);
+	int ret;
+
+	switch (info) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		ret = regmap_write(st->regmap, ADA4250_REG_GAIN_MUX,
+				   FIELD_PREP(ADA4250_GAIN_MUX_MSK, ilog2(val)));
+		if (ret)
+			return ret;
+
+		st->gain = ilog2(val);
+
+		return ret;
+	case IIO_CHAN_INFO_OFFSET:
+		return ada4250_set_offset_uv(indio_dev, chan, val);
+	case IIO_CHAN_INFO_CALIBBIAS:
+		ret = regmap_update_bits(st->regmap, ADA4250_REG_SNSR_CAL_CNFG,
+					 ADA4250_BIAS_SET_MSK,
+					 FIELD_PREP(ADA4250_BIAS_SET_MSK, val));
+		if (ret)
+			return ret;
+
+		st->bias = val;
+
+		return ret;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ada4250_read_avail(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      const int **vals, int *type, int *length,
+			      long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_CALIBBIAS:
+		*vals = calibbias_table;
+		*type = IIO_VAL_INT;
+		*length = ARRAY_SIZE(calibbias_table);
+
+		return IIO_AVAIL_LIST;
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		*vals = hwgain_table;
+		*type = IIO_VAL_INT;
+		*length = ARRAY_SIZE(hwgain_table);
+
+		return IIO_AVAIL_LIST;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ada4250_reg_access(struct iio_dev *indio_dev,
+			      unsigned int reg,
+			      unsigned int write_val,
+			      unsigned int *read_val)
+{
+	struct ada4250_state *st = iio_priv(indio_dev);
+
+	if (read_val)
+		return regmap_read(st->regmap, reg, read_val);
+	else
+		return regmap_write(st->regmap, reg, write_val);
+}
+
+static const struct iio_info ada4250_info = {
+	.read_raw = ada4250_read_raw,
+	.write_raw = ada4250_write_raw,
+	.read_avail = &ada4250_read_avail,
+	.debugfs_reg_access = &ada4250_reg_access,
+};
+
+static const struct iio_chan_spec ada4250_channels[] = {
+	{
+		.type = IIO_VOLTAGE,
+		.output = 1,
+		.indexed = 1,
+		.channel = 0,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN) |
+				BIT(IIO_CHAN_INFO_OFFSET) |
+				BIT(IIO_CHAN_INFO_CALIBBIAS) |
+				BIT(IIO_CHAN_INFO_SCALE),
+		.info_mask_separate_available = BIT(IIO_CHAN_INFO_CALIBBIAS) |
+						BIT(IIO_CHAN_INFO_HARDWAREGAIN),
+	}
+};
+
+static int ada4250_init(struct ada4250_state *st)
+{
+	struct device *dev = &st->spi->dev;
+	int ret;
+	u16 chip_id;
+
+	st->refbuf_en = device_property_read_bool(dev, "adi,refbuf-enable");
+
+	st->avdd_uv = devm_regulator_get_enable_read_voltage(dev, "avdd");
+	if (st->avdd_uv < 0)
+		return dev_err_probe(dev, st->avdd_uv,
+				     "failed to get the AVDD voltage\n");
+
+	ret = regmap_write(st->regmap, ADA4250_REG_RESET,
+			   FIELD_PREP(ADA4250_RESET_MSK, 1));
+	if (ret)
+		return ret;
+
+	ret = regmap_bulk_read(st->regmap, ADA4250_REG_CHIP_ID, &st->reg_val_16,
+			       sizeof(st->reg_val_16));
+	if (ret)
+		return ret;
+
+	chip_id = le16_to_cpu(st->reg_val_16);
+
+	if (chip_id != ADA4250_CHIP_ID)
+		dev_info(dev, "Invalid chip ID: 0x%02X.\n", chip_id);
+
+	return regmap_write(st->regmap, ADA4250_REG_REFBUF_EN,
+			    FIELD_PREP(ADA4250_REFBUF_MSK, st->refbuf_en));
+}
+
+static int ada4250_probe(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev;
+	struct regmap *regmap;
+	struct ada4250_state *st;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	regmap = devm_regmap_init_spi(spi, &ada4250_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	st = iio_priv(indio_dev);
+	st->regmap = regmap;
+	st->spi = spi;
+
+	indio_dev->info = &ada4250_info;
+	indio_dev->name = "ada4250";
+	indio_dev->channels = ada4250_channels;
+	indio_dev->num_channels = ARRAY_SIZE(ada4250_channels);
+
+	mutex_init(&st->lock);
+
+	ret = ada4250_init(st);
+	if (ret)
+		return dev_err_probe(&spi->dev, ret, "ADA4250 init failed\n");
+
+	return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct spi_device_id ada4250_id[] = {
+	{ .name = "ada4250" },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, ada4250_id);
+
+static const struct of_device_id ada4250_of_match[] = {
+	{ .compatible = "adi,ada4250" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ada4250_of_match);
+
+static struct spi_driver ada4250_driver = {
+	.driver = {
+			.name = "ada4250",
+			.of_match_table = ada4250_of_match,
+		},
+	.probe = ada4250_probe,
+	.id_table = ada4250_id,
+};
+module_spi_driver(ada4250_driver);
+
+MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com");
+MODULE_DESCRIPTION("Analog Devices ADA4250");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/amplifiers/adl8113.c b/drivers/iio/amplifiers/adl8113.c
new file mode 100644
index 000000000..1f1cfca98
--- /dev/null
+++ b/drivers/iio/amplifiers/adl8113.c
@@ -0,0 +1,268 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ADL8113 Low Noise Amplifier with integrated bypass switches
+ *
+ * Copyright 2025 Analog Devices Inc.
+ */
+
+#include <linux/array_size.h>
+#include <linux/bitmap.h>
+#include <linux/device/driver.h>
+#include <linux/dev_printk.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+#include <linux/types.h>
+
+enum adl8113_signal_path {
+	ADL8113_INTERNAL_AMP,
+	ADL8113_INTERNAL_BYPASS,
+	ADL8113_EXTERNAL_A,
+	ADL8113_EXTERNAL_B,
+};
+
+struct adl8113_gain_config {
+	enum adl8113_signal_path path;
+	int gain_db;
+};
+
+struct adl8113_state {
+	struct gpio_descs *gpios;
+	struct adl8113_gain_config *gain_configs;
+	unsigned int num_gain_configs;
+	enum adl8113_signal_path current_path;
+};
+
+static const char * const adl8113_supply_names[] = {
+	"vdd1",
+	"vss2",
+	"vdd2",
+};
+
+static int adl8113_set_path(struct adl8113_state *st,
+			    enum adl8113_signal_path path)
+{
+	DECLARE_BITMAP(values, 2);
+	int ret;
+
+	/*
+	 * Determine GPIO values based on signal path.
+	 * Va: bit 0, Vb: bit 1.
+	 */
+	switch (path) {
+	case ADL8113_INTERNAL_AMP:
+		bitmap_write(values, 0x00, 0, 2);
+		break;
+	case ADL8113_INTERNAL_BYPASS:
+		bitmap_write(values, 0x03, 0, 2);
+		break;
+	case ADL8113_EXTERNAL_A:
+		bitmap_write(values, 0x02, 0, 2);
+		break;
+	case ADL8113_EXTERNAL_B:
+		bitmap_write(values, 0x01, 0, 2);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = gpiod_set_array_value_cansleep(st->gpios->ndescs, st->gpios->desc,
+					     st->gpios->info, values);
+	if (ret)
+		return ret;
+
+	st->current_path = path;
+	return 0;
+}
+
+static int adl8113_find_gain_config(struct adl8113_state *st, int gain_db)
+{
+	unsigned int i;
+
+	for (i = 0; i < st->num_gain_configs; i++) {
+		if (st->gain_configs[i].gain_db == gain_db)
+			return i;
+	}
+	return -EINVAL;
+}
+
+static const struct iio_chan_spec adl8113_channels[] = {
+	{
+		.type = IIO_VOLTAGE,
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_HARDWAREGAIN),
+	},
+};
+
+static int adl8113_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long mask)
+{
+	struct adl8113_state *st = iio_priv(indio_dev);
+	unsigned int i;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		/* Find current gain configuration */
+		for (i = 0; i < st->num_gain_configs; i++) {
+			if (st->gain_configs[i].path == st->current_path) {
+				*val = st->gain_configs[i].gain_db;
+				*val2 = 0;
+				return IIO_VAL_INT_PLUS_MICRO_DB;
+			}
+		}
+		return -EINVAL;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int adl8113_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int val, int val2, long mask)
+{
+	struct adl8113_state *st = iio_priv(indio_dev);
+	int config_idx;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		if (val2 != 0)
+			return -EINVAL;
+
+		config_idx = adl8113_find_gain_config(st, val);
+		if (config_idx < 0)
+			return config_idx;
+
+		return adl8113_set_path(st, st->gain_configs[config_idx].path);
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info adl8113_info = {
+	.read_raw = adl8113_read_raw,
+	.write_raw = adl8113_write_raw,
+};
+
+static int adl8113_init_gain_configs(struct device *dev, struct adl8113_state *st)
+{
+	int external_a_gain, external_b_gain;
+	unsigned int i;
+
+	/*
+	 * Allocate for all 4 possible paths:
+	 * - Internal amp and bypass (always present)
+	 * - External bypass A and B (optional if configured)
+	 */
+	st->gain_configs = devm_kcalloc(dev, 4, sizeof(*st->gain_configs),
+					GFP_KERNEL);
+	if (!st->gain_configs)
+		return -ENOMEM;
+
+	/* Start filling the gain configurations with data */
+	i = 0;
+
+	/* Always include internal amplifier (14dB) */
+	st->gain_configs[i++] = (struct adl8113_gain_config) {
+		.path = ADL8113_INTERNAL_AMP,
+		.gain_db = 14,
+	};
+
+	/* Always include internal bypass (-2dB insertion loss) */
+	st->gain_configs[i++] = (struct adl8113_gain_config) {
+		.path = ADL8113_INTERNAL_BYPASS,
+		.gain_db = -2,
+	};
+
+	/* Add external bypass A if configured */
+	if (!device_property_read_u32(dev, "adi,external-bypass-a-gain-db",
+				      &external_a_gain)) {
+		st->gain_configs[i++] = (struct adl8113_gain_config) {
+			.path = ADL8113_EXTERNAL_A,
+			.gain_db = external_a_gain,
+		};
+	}
+
+	/* Add external bypass B if configured */
+	if (!device_property_read_u32(dev, "adi,external-bypass-b-gain-db",
+				      &external_b_gain)) {
+		st->gain_configs[i++] = (struct adl8113_gain_config) {
+			.path = ADL8113_EXTERNAL_B,
+			.gain_db = external_b_gain,
+		};
+	}
+
+	st->num_gain_configs = i;
+
+	return 0;
+}
+
+static int adl8113_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct adl8113_state *st;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+
+	st->gpios = devm_gpiod_get_array(dev, "ctrl", GPIOD_OUT_LOW);
+	if (IS_ERR(st->gpios))
+		return dev_err_probe(dev, PTR_ERR(st->gpios),
+				     "failed to get control GPIOs\n");
+
+	if (st->gpios->ndescs != 2)
+		return dev_err_probe(dev, -EINVAL,
+				     "expected 2 control GPIOs, got %u\n",
+				     st->gpios->ndescs);
+
+	ret = devm_regulator_bulk_get_enable(dev,
+					     ARRAY_SIZE(adl8113_supply_names),
+					     adl8113_supply_names);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "failed to get and enable supplies\n");
+
+	/* Initialize gain configurations from devicetree */
+	ret = adl8113_init_gain_configs(dev, st);
+	if (ret)
+		return ret;
+
+	/* Initialize to internal amplifier path (14dB) */
+	ret = adl8113_set_path(st, ADL8113_INTERNAL_AMP);
+	if (ret)
+		return ret;
+
+	indio_dev->info = &adl8113_info;
+	indio_dev->name = "adl8113";
+	indio_dev->channels = adl8113_channels;
+	indio_dev->num_channels = ARRAY_SIZE(adl8113_channels);
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct of_device_id adl8113_of_match[] = {
+	{ .compatible = "adi,adl8113" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, adl8113_of_match);
+
+static struct platform_driver adl8113_driver = {
+	.driver = {
+		.name = "adl8113",
+		.of_match_table = adl8113_of_match,
+	},
+	.probe = adl8113_probe,
+};
+module_platform_driver(adl8113_driver);
+
+MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com>");
+MODULE_DESCRIPTION("Analog Devices ADL8113 Low Noise Amplifier");
+MODULE_LICENSE("GPL");
diff --git a/drivers/iio/amplifiers/hmc425a.c b/drivers/iio/amplifiers/hmc425a.c
new file mode 100644
index 000000000..85bfc8dcc
--- /dev/null
+++ b/drivers/iio/amplifiers/hmc425a.c
@@ -0,0 +1,424 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * HMC425A and similar Gain Amplifiers
+ *
+ * Copyright 2020, 2024 Analog Devices Inc.
+ */
+
+#include <linux/bits.h>
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/kernel.h>
+#include <linux/math.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+#include <linux/regulator/consumer.h>
+#include <linux/sysfs.h>
+
+/*
+ * The LTC6373 amplifier supports configuring gain using GPIO's with the following
+ *  values (OUTPUT_V / INPUT_V): 0(shutdown), 0.25, 0.5, 1, 2, 4, 8, 16
+ *
+ * Except for the shutdown value, all can be converted to dB using 20 * log10(x)
+ * From here, it is observed that all values are multiples of the '2' gain setting,
+ *  with the correspondent of 6.020dB.
+ */
+#define LTC6373_CONVERSION_CONSTANT	6020
+#define LTC6373_MIN_GAIN_CODE		0x6
+#define LTC6373_CONVERSION_MASK		GENMASK(2, 0)
+#define LTC6373_SHUTDOWN		GENMASK(2, 0)
+
+enum hmc425a_type {
+	ID_HMC425A,
+	ID_HMC540S,
+	ID_ADRF5740,
+	ID_LTC6373,
+};
+
+struct hmc425a_chip_info {
+	const char			*name;
+	const struct iio_chan_spec	*channels;
+	unsigned int			num_channels;
+	unsigned int			num_gpios;
+	int				gain_min;
+	int				gain_max;
+	int				default_gain;
+	int				powerdown_val;
+	bool				has_powerdown;
+
+	int				(*gain_dB_to_code)(int gain, int *code);
+	int				(*code_to_gain_dB)(int code, int *val, int *val2);
+};
+
+struct hmc425a_state {
+	struct	mutex lock; /* protect sensor state */
+	const struct	hmc425a_chip_info *chip_info;
+	struct	gpio_descs *gpios;
+	u32	gain;
+	bool	powerdown;
+};
+
+static int gain_dB_to_code(struct hmc425a_state *st, int val, int val2, int *code)
+{
+	const struct hmc425a_chip_info *inf = st->chip_info;
+	int gain;
+
+	if (val < 0)
+		gain = (val * 1000) - (val2 / 1000);
+	else
+		gain = (val * 1000) + (val2 / 1000);
+
+	if (gain > inf->gain_max || gain < inf->gain_min)
+		return -EINVAL;
+	if (st->powerdown)
+		return -EPERM;
+
+	return st->chip_info->gain_dB_to_code(gain, code);
+}
+
+static int hmc425a_gain_dB_to_code(int gain, int *code)
+{
+	*code = ~((abs(gain) / 500) & 0x3F);
+	return 0;
+}
+
+static int hmc540s_gain_dB_to_code(int gain, int *code)
+{
+	*code = ~((abs(gain) / 1000) & 0xF);
+	return 0;
+}
+
+static int adrf5740_gain_dB_to_code(int gain, int *code)
+{
+	int temp = (abs(gain) / 2000) & 0xF;
+
+	/* Bit [0-3]: 2dB 4dB 8dB 8dB */
+	*code = temp & BIT(3) ? temp | BIT(2) : temp;
+	return 0;
+}
+
+static int ltc6373_gain_dB_to_code(int gain, int *code)
+{
+	*code = ~(DIV_ROUND_CLOSEST(gain, LTC6373_CONVERSION_CONSTANT) + 3)
+		& LTC6373_CONVERSION_MASK;
+	return 0;
+}
+
+static int code_to_gain_dB(struct hmc425a_state *st, int *val, int *val2)
+{
+	if (st->powerdown)
+		return -EPERM;
+	return st->chip_info->code_to_gain_dB(st->gain, val, val2);
+}
+
+static int hmc425a_code_to_gain_dB(int code, int *val, int *val2)
+{
+	*val = (~code * -500) / 1000;
+	*val2 = ((~code * -500) % 1000) * 1000;
+	return 0;
+}
+
+static int hmc540s_code_to_gain_dB(int code, int *val, int *val2)
+{
+	*val = (~code * -1000) / 1000;
+	*val2 = ((~code * -1000) % 1000) * 1000;
+	return 0;
+}
+
+static int adrf5740_code_to_gain_dB(int code, int *val, int *val2)
+{
+	/*
+	 * Bit [0-3]: 2dB 4dB 8dB 8dB
+	 * When BIT(3) is set, unset BIT(2) and use 3 as double the place value
+	 */
+	code = code & BIT(3) ? code & ~BIT(2) : code;
+	*val = (code * -2000) / 1000;
+	*val2 = ((code * -2000) % 1000) * 1000;
+	return 0;
+}
+
+static int ltc6373_code_to_gain_dB(int code, int *val, int *val2)
+{
+	int gain = ((~code & LTC6373_CONVERSION_MASK) - 3) *
+		   LTC6373_CONVERSION_CONSTANT;
+
+	*val = gain / 1000;
+	*val2 = (gain % 1000) * 1000;
+	return 0;
+}
+
+static int hmc425a_write(struct iio_dev *indio_dev, u32 value)
+{
+	struct hmc425a_state *st = iio_priv(indio_dev);
+	DECLARE_BITMAP(values, BITS_PER_TYPE(value));
+
+	values[0] = value;
+
+	gpiod_multi_set_value_cansleep(st->gpios, values);
+	return 0;
+}
+
+static int hmc425a_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan, int *val,
+			    int *val2, long m)
+{
+	struct hmc425a_state *st = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&st->lock);
+	switch (m) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		ret = code_to_gain_dB(st, val, val2);
+		if (ret)
+			break;
+		ret = IIO_VAL_INT_PLUS_MICRO_DB;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	mutex_unlock(&st->lock);
+
+	return ret;
+};
+
+static int hmc425a_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan, int val,
+			     int val2, long mask)
+{
+	struct hmc425a_state *st = iio_priv(indio_dev);
+	int code = 0, ret;
+
+	mutex_lock(&st->lock);
+	switch (mask) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		ret = gain_dB_to_code(st, val, val2, &code);
+		if (ret)
+			break;
+		st->gain = code;
+
+		ret = hmc425a_write(indio_dev, st->gain);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int hmc425a_write_raw_get_fmt(struct iio_dev *indio_dev,
+				     struct iio_chan_spec const *chan,
+				     long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		return IIO_VAL_INT_PLUS_MICRO_DB;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info hmc425a_info = {
+	.read_raw = &hmc425a_read_raw,
+	.write_raw = &hmc425a_write_raw,
+	.write_raw_get_fmt = &hmc425a_write_raw_get_fmt,
+};
+
+static ssize_t ltc6373_read_powerdown(struct iio_dev *indio_dev,
+				      uintptr_t private,
+				      const struct iio_chan_spec *chan,
+				      char *buf)
+{
+	struct hmc425a_state *st = iio_priv(indio_dev);
+
+	return sysfs_emit(buf, "%d\n", st->powerdown);
+}
+
+static ssize_t ltc6373_write_powerdown(struct iio_dev *indio_dev,
+				       uintptr_t private,
+				       const struct iio_chan_spec *chan,
+				       const char *buf,
+				       size_t len)
+{
+	struct hmc425a_state *st = iio_priv(indio_dev);
+	bool powerdown;
+	int code, ret;
+
+	ret = kstrtobool(buf, &powerdown);
+	if (ret)
+		return ret;
+
+	mutex_lock(&st->lock);
+	st->powerdown = powerdown;
+	code = (powerdown) ? LTC6373_SHUTDOWN : st->gain;
+	hmc425a_write(indio_dev, code);
+	mutex_unlock(&st->lock);
+	return len;
+}
+
+static const struct iio_chan_spec_ext_info ltc6373_ext_info[] = {
+	{
+		.name = "powerdown",
+		.read = ltc6373_read_powerdown,
+		.write = ltc6373_write_powerdown,
+		.shared = IIO_SEPARATE,
+	},
+	{ }
+};
+
+#define HMC425A_CHAN(_channel)						\
+{									\
+	.type = IIO_VOLTAGE,						\
+	.output = 1,							\
+	.indexed = 1,							\
+	.channel = _channel,						\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN),		\
+}
+
+#define LTC6373_CHAN(_channel)						\
+{									\
+	.type = IIO_VOLTAGE,						\
+	.output = 1,							\
+	.indexed = 1,							\
+	.channel = _channel,						\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN),		\
+	.ext_info = ltc6373_ext_info,					\
+}
+
+static const struct iio_chan_spec hmc425a_channels[] = {
+	HMC425A_CHAN(0),
+};
+
+static const struct iio_chan_spec ltc6373_channels[] = {
+	LTC6373_CHAN(0),
+};
+
+static const struct hmc425a_chip_info hmc425a_chip_info_tbl[] = {
+	[ID_HMC425A] = {
+		.name = "hmc425a",
+		.channels = hmc425a_channels,
+		.num_channels = ARRAY_SIZE(hmc425a_channels),
+		.num_gpios = 6,
+		.gain_min = -31500,
+		.gain_max = 0,
+		.default_gain = -0x40, /* set default gain -31.5db*/
+		.gain_dB_to_code = hmc425a_gain_dB_to_code,
+		.code_to_gain_dB = hmc425a_code_to_gain_dB,
+	},
+	[ID_HMC540S] = {
+		.name = "hmc540s",
+		.channels = hmc425a_channels,
+		.num_channels = ARRAY_SIZE(hmc425a_channels),
+		.num_gpios = 4,
+		.gain_min = -15000,
+		.gain_max = 0,
+		.default_gain = -0x10, /* set default gain -15.0db*/
+		.gain_dB_to_code = hmc540s_gain_dB_to_code,
+		.code_to_gain_dB = hmc540s_code_to_gain_dB,
+	},
+	[ID_ADRF5740] = {
+		.name = "adrf5740",
+		.channels = hmc425a_channels,
+		.num_channels = ARRAY_SIZE(hmc425a_channels),
+		.num_gpios = 4,
+		.gain_min = -22000,
+		.gain_max = 0,
+		.default_gain = 0xF, /* set default gain -22.0db*/
+		.gain_dB_to_code = adrf5740_gain_dB_to_code,
+		.code_to_gain_dB = adrf5740_code_to_gain_dB,
+	},
+	[ID_LTC6373] = {
+		.name = "ltc6373",
+		.channels = ltc6373_channels,
+		.num_channels = ARRAY_SIZE(ltc6373_channels),
+		.num_gpios = 3,
+		.gain_min = -12041, /* gain setting x0.25*/
+		.gain_max = 24082,  /* gain setting x16  */
+		.default_gain = LTC6373_MIN_GAIN_CODE,
+		.powerdown_val = LTC6373_SHUTDOWN,
+		.has_powerdown = true,
+		.gain_dB_to_code = ltc6373_gain_dB_to_code,
+		.code_to_gain_dB = ltc6373_code_to_gain_dB,
+	},
+};
+
+static int hmc425a_probe(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev;
+	struct hmc425a_state *st;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+
+	st->chip_info = device_get_match_data(&pdev->dev);
+	indio_dev->num_channels = st->chip_info->num_channels;
+	indio_dev->channels = st->chip_info->channels;
+	indio_dev->name = st->chip_info->name;
+	st->gain = st->chip_info->default_gain;
+
+	st->gpios = devm_gpiod_get_array(&pdev->dev, "ctrl", GPIOD_OUT_LOW);
+	if (IS_ERR(st->gpios))
+		return dev_err_probe(&pdev->dev, PTR_ERR(st->gpios),
+				     "failed to get gpios\n");
+
+	if (st->gpios->ndescs != st->chip_info->num_gpios) {
+		dev_err(&pdev->dev, "%d GPIOs needed to operate\n",
+			st->chip_info->num_gpios);
+		return -ENODEV;
+	}
+
+	ret = devm_regulator_get_enable(&pdev->dev, "vcc-supply");
+	if (ret)
+		return ret;
+
+	mutex_init(&st->lock);
+
+	indio_dev->info = &hmc425a_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	if (st->chip_info->has_powerdown) {
+		st->powerdown = true;
+		hmc425a_write(indio_dev, st->chip_info->powerdown_val);
+	} else {
+		/* Set default gain */
+		hmc425a_write(indio_dev, st->gain);
+	}
+
+	return devm_iio_device_register(&pdev->dev, indio_dev);
+}
+
+static const struct of_device_id hmc425a_of_match[] = {
+	{ .compatible = "adi,hmc425a",
+	  .data = &hmc425a_chip_info_tbl[ID_HMC425A]},
+	{ .compatible = "adi,hmc540s",
+	  .data = &hmc425a_chip_info_tbl[ID_HMC540S]},
+	{ .compatible = "adi,adrf5740",
+	  .data = &hmc425a_chip_info_tbl[ID_ADRF5740]},
+	{ .compatible = "adi,ltc6373",
+	  .data = &hmc425a_chip_info_tbl[ID_LTC6373]},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, hmc425a_of_match);
+
+static struct platform_driver hmc425a_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = hmc425a_of_match,
+	},
+	.probe = hmc425a_probe,
+};
+module_platform_driver(hmc425a_driver);
+
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
+MODULE_DESCRIPTION("Analog Devices HMC425A and similar GPIO control Gain Amplifiers");
+MODULE_LICENSE("GPL v2");