Add documentation for AD7191 driver. Signed-off-by: Alisa-Dariana Roman <alisa.roman@xxxxxxxxxx> --- Documentation/iio/ad7191.rst | 129 +++++++++++++++++++++++++++++++++++ Documentation/iio/index.rst | 1 + MAINTAINERS | 1 + 3 files changed, 131 insertions(+) create mode 100644 Documentation/iio/ad7191.rst diff --git a/Documentation/iio/ad7191.rst b/Documentation/iio/ad7191.rst new file mode 100644 index 000000000000..6ab615ea457b --- /dev/null +++ b/Documentation/iio/ad7191.rst @@ -0,0 +1,129 @@ +.. SPDX-License-Identifier: GPL-2.0-only + +============= +AD7191 driver +============= + +Device driver for Analog Devices AD7191 ADC. + +================= +Supported devices +================= + +* `AD7191 <https://www.analog.com/AD7191>`_ + +The AD7191 is a high precision, low noise, 24-bit Σ-Δ ADC with integrated PGA. +It features two differential input channels, an internal temperature sensor, and +configurable sampling rates. + +========== +Devicetree +========== + +----------------- +Pin Configuration +----------------- + +The driver supports both pin-strapped and GPIO-controlled configurations for ODR +(Output Data Rate) and PGA (Programmable Gain Amplifier) settings. These +configurations are mutually exclusive - you must use either pin-strapped or GPIO +control for each setting, not both. + +^^^^^^^^^^^^^^^^^ +ODR Configuration +^^^^^^^^^^^^^^^^^ + +The ODR can be configured either through GPIO control or pin-strapping: + +- When using GPIO control, specify the "odr-gpios" property in the device tree +- For pin-strapped configuration, specify the "adi,odr-value" property in the + device tree + +Available ODR settings: + + - 120 Hz (ODR1=0, ODR2=0) + - 60 Hz (ODR1=0, ODR2=1) + - 50 Hz (ODR1=1, ODR2=0) + - 10 Hz (ODR1=1, ODR2=1) + +^^^^^^^^^^^^^^^^^ +PGA Configuration +^^^^^^^^^^^^^^^^^ + +The PGA can be configured either through GPIO control or pin-strapping: + +- When using GPIO control, specify the "pga-gpios" property in the device tree +- For pin-strapped configuration, specify the "adi,pga-value" property in the + device tree + +Available PGA gain settings: + + - 1x (PGA1=0, PGA2=0) + - 8x (PGA1=0, PGA2=1) + - 64x (PGA1=1, PGA2=0) + - 128x (PGA1=1, PGA2=1) + +------------------- +Clock Configuration +------------------- + +The AD7191 supports both internal and external clock sources: + +- When CLKSEL pin is tied LOW: Uses internal 4.92MHz clock (no clock property + needed) +- When CLKSEL pin is tied HIGH: Requires external clock source + - Can be a crystal between MCLK1 and MCLK2 pins + - Or a CMOS-compatible clock driving MCLK2 pin + - Must specify the "clocks" property in device tree when using external clock + +-------------------------- +SPI Interface Requirements +-------------------------- + +The AD7191 has specific SPI interface requirements: + +- The DOUT/RDY output is dual-purpose and requires SPI bus locking +- DOUT/RDY must be connected to an interrupt-capable GPIO +- The SPI controller's chip select must be connected to the PDOWN pin of the ADC +- When CS (PDOWN) is high, the device powers down and resets internal circuitry +- SPI mode 3 operation (CPOL=1, CPHA=1) is required + +------------------------- +Power Supply Requirements +------------------------- + +The device requires the following power supplies: + +- AVdd: Analog power supply +- DVdd: Digital power supply +- Vref: Reference voltage supply (external) + +All power supplies must be specified in the device tree. + +===================== +Channel Configuration +===================== + +The device provides three channels: + +1. Temperature Sensor + - 24-bit unsigned + - Internal temperature measurement + - Temperature in millidegrees Celsius + +2. Differential Input (AIN1-AIN2) + - 24-bit unsigned + - Differential voltage measurement + - Configurable gain via PGA + +3. Differential Input (AIN3-AIN4) + - 24-bit unsigned + - Differential voltage measurement + - Configurable gain via PGA + +============== +Buffer Support +============== + +This driver supports IIO triggered buffers. See Documentation/iio/iio_devbuf.rst +for more information about IIO triggered buffers. diff --git a/Documentation/iio/index.rst b/Documentation/iio/index.rst index 2d334be2b7f2..edc984a38b3b 100644 --- a/Documentation/iio/index.rst +++ b/Documentation/iio/index.rst @@ -21,6 +21,7 @@ Industrial I/O Kernel Drivers ad4000 ad4030 ad4695 + ad7191 ad7380 ad7606 ad7625 diff --git a/MAINTAINERS b/MAINTAINERS index 87c491975ced..0547a3bb528c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1352,6 +1352,7 @@ L: linux-iio@xxxxxxxxxxxxxxx S: Supported W: https://ez.analog.com/linux-software-drivers F: Documentation/devicetree/bindings/iio/adc/adi,ad7191.yaml +F: Documentation/iio/ad7191.rst F: drivers/iio/adc/ad7191.c ANALOG DEVICES INC AD7192 DRIVER -- 2.43.0
