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AD4170-4 backport to main#3190

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machschmitt wants to merge 12 commits intoanalogdevicesinc:mainfrom
machschmitt:main-ad4170-backport
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AD4170-4 backport to main#3190
machschmitt wants to merge 12 commits intoanalogdevicesinc:mainfrom
machschmitt:main-ad4170-backport

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@machschmitt machschmitt commented Mar 13, 2026

PR Description

Backport ad4170-4 driver from upstream IIO tree.
Last 4 commits adapt the upstream driver to kernel 6.12.

PR Type

  • Bug fix (a change that fixes an issue)
  • New feature (a change that adds new functionality)
  • Breaking change (a change that affects other repos or cause CIs to fail)

PR Checklist

  • I have conducted a self-review of my own code changes
  • I have compiled my changes, including the documentation
  • I have tested the changes on the relevant hardware
  • I have updated the documentation outside this repo accordingly
  • I have provided links for the relevant upstream lore

machschmitt and others added 6 commits March 13, 2026 15:56
@machschmitt
dt-bindings: iio: adc: Add AD4170-4
91fe4c5 
Add device tree documentation for AD4170-4 and similar sigma-delta ADCs.
The AD4170-4 is a 24-bit, multichannel, sigma-delta ADC.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Link: https://patch.msgid.link/aa4b3be541c7b759560f8e0c5340a456cb2f3801.1751895245.git.marcelo.schmitt@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
@acusco @machschmitt
iio: adc: Add basic support for AD4170-4
dcc42ee 
The AD4170-4 is a multichannel, low noise, 24-bit precision sigma-delta
analog to digital converter. The AD4170-4 design offers a flexible data
acquisition solution with crosspoint multiplexed analog inputs,
configurable ADC voltage reference inputs, ultra-low noise integrated PGA,
digital filtering, wide range of configurable output data rates, internal
oscillator and temperature sensor, four GPIOs, and integrated features for
interfacing with load cell weigh scales, RTD, and thermocouple sensors.

Add basic support for the AD4170-4 ADC with the following features:
- Single-shot read.
- Analog front end PGA configuration.
- Differential and pseudo-differential input configuration.

Signed-off-by: Ana-Maria Cusco <ana-maria.cusco@analog.com>
Co-developed-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Link: https://patch.msgid.link/ce3fd150bd63a2aed6eb6fe59aad6d60c0f9fb67.1751895245.git.marcelo.schmitt@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
@machschmitt
iio: adc: ad4170-4: Add support for calibration gain
866f9db 
Add support for ADC calibration gain configuration.

Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Link: https://patch.msgid.link/ea8d07cad9b7b6106f0b5664c403ed080b362a6b.1751895245.git.marcelo.schmitt@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
@machschmitt
iio: adc: ad4170-4: Add support for calibration bias
2347e4e 
Add support for ADC calibration bias/offset configuration.

Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Link: https://patch.msgid.link/f240fce693d62ec8d587885074bf540e01919b31.1751895245.git.marcelo.schmitt@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
@machschmitt
iio: adc: ad4170-4: Add digital filter and sample frequency config su…
6793a46 
…pport

Add support for sinc3, sinc5, and averaged sinc5 digital filters along with
sample frequency configuration.

Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Link: https://patch.msgid.link/31f4226b4172b0bbb26daa054b74b25b1966c7b2.1751895245.git.marcelo.schmitt@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
@machschmitt
iio: adc: ad4170-4: Add support for buffered data capture
3023fa7 
Extend the AD4170-4 driver to allow buffered data capture in continuous
read mode. In continuous read mode, the chip skips the instruction phase
and outputs just ADC sample data, enabling faster sample rates to be
reached. The internal channel sequencer always starts sampling from channel
0 and channel 0 must be enabled if more than one channel is selected for
data capture. The scan mask validation callback checks if the
aforementioned condition is met.

Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Link: https://patch.msgid.link/10ed544d31aa86eb40f93ea947f151d3d9827952.1751895245.git.marcelo.schmitt@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
nunojsa
nunojsa reviewed Mar 14, 2026
View reviewed changes
drivers/iio/adc/ad4170-4.c
}

static int ad4170_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
static void ad4170_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
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This is odd. Please adapt this in the patch you're cherry-picking and add a proper comment. Like 6.12 backport needed change.

Like this, we have commits that don't compile

drivers/iio/adc/ad4170-4.c
st->gpiochip.direction_output = ad4170_gpio_direction_output;
st->gpiochip.get = ad4170_gpio_get;
st->gpiochip.set_rv = ad4170_gpio_set;
st->gpiochip.set = ad4170_gpio_set;
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Like before, we likely don't need this patch for the backport. Adapt things on the proper patch please and make sure the kernel is compilable.

drivers/iio/adc/ad4170-4.c Outdated
if (!!value)
return regmap_set_bits(st->regmap, AD4170_GPIO_OUTPUT_REG, BIT(offset));
else
return regmap_clear_bits(st->regmap, AD4170_GPIO_OUTPUT_REG, BIT(offset));
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Again seems like this patch is not needed. Also you're introducing a bug here 😉

@machschmitt
iio: adc: ad4170-4: Add timestamp channel
345b960 
Add timestamp channel allowing to record the moment at which ADC samples
are captured in buffered read mode.

[marcelo.schmitt@analog.com: Adapt to use iio_push_to_buffers_with_timestamp()]
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Link: https://patch.msgid.link/e0af7e5424898bee0f3edfbb017133624efc169d.1751895245.git.marcelo.schmitt@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
@machschmitt
iio: adc: ad4170-4: Add clock provider support
5adea0a 
The AD4170-4 chip can use an externally supplied clock at the XTAL2 pin, or
an external crystal connected to the XTAL1 and XTAL2 pins. Alternatively,
the AD4170-4 can provide its 16 MHz internal clock at the XTAL2 pin. In
addition, the chip has a programmable clock divider that allows dividing
the external or internal clock frequency, however, control for that is not
provided in this patch. Extend the AD4170-4 driver so it effectively uses
the provided external clock, if any, or supplies its own clock as a clock
provider.

Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Link: https://patch.msgid.link/68697c7613b1a69d752e541caef28d08b3e59bc1.1751895245.git.marcelo.schmitt@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
@machschmitt
iio: adc: ad4170-4: Add GPIO controller support
c90373b 
The AD4170-4 has four multifunctional pins that can be used as GPIOs. The
GPIO functionality can be accessed when the AD4170-4 chip is not busy
performing continuous data capture or handling any other register
read/write request. Also, the AD4170-4 does not provide any interrupt based
on GPIO pin states so AD4170-4 GPIOs can't be used as interrupt sources.

Implement gpio_chip callbacks to make AD4170-4 GPIO pins controllable
through the gpiochip interface.

[marcelo.schmitt@analog.com: Adapted with 6.12 backport needed changes]
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Link: https://patch.msgid.link/e031189d4b7e20cf02dd13220ab1ddf4798760c2.1751895245.git.marcelo.schmitt@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
@machschmitt
iio: adc: ad4170-4: Add support for internal temperature sensor
116d726 
The AD4170-4 has an internal temperature sensor that can be read using the
ADC. Whenever possible, configure an IIO channel to provide the chip's
temperature.

Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Link: https://patch.msgid.link/71ac994060cf79a6c49f39b0c7d04c6c9cbbab00.1751895245.git.marcelo.schmitt@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
@machschmitt
iio: adc: ad4170-4: Add support for weigh scale, thermocouple, and RT…
ee1c56d 
…D sens

The AD4170-4 design provides features to aid interfacing with weigh scales,
thermocouples, and RTD sensors, which are set up with additional circuitry
for proper sensor operation. A key characteristic of those sensors is that
the circuit they are in must be excited with a single, a pair, or two pairs
of signals. The external circuit can be excited either by a voltage supply
or by AD4170-4 excitation signals. The sensor can then be read through a
different pair of lines that are connected to the AD4170-4 ADC.

Extend the ad4170-4 driver to handle external circuit sensors.

Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
Link: https://patch.msgid.link/52686943040ecad34cc89833d4d5d37f1a51f412.1751895245.git.marcelo.schmitt@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
@machschmitt
iio: Kconfig.adi: imply AD4170_4
7305670 
Automatically imply ADF4170_4.

Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
@machschmitt machschmitt force-pushed the main-ad4170-backport branch from 88d90da to 7305670 Compare March 16, 2026 14:55
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machschmitt commented Mar 16, 2026 •
edited
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Squashed commits with adaptations for kernel 6.12 with the patches for each respective functionality. Added a brief "tag" to commit messages indicating which patches were adapted.

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@machschmitt @nunojsa @acusco