On Fri, Apr 25, 2025 at 04:44:20PM -0500, David Lechner wrote: > On 4/22/25 6:34 AM, Jorge Marques wrote: > > This adds a new page to document how to use the ad4052 ADC driver. > > > > Signed-off-by: Jorge Marques <jorge.marques@xxxxxxxxxx> > > --- > > Documentation/iio/ad4052.rst | 95 ++++++++++++++++++++++++++++++++++++++++++++ > > Also need to update the table of contents in Documentation/iio/index.rst, > otherwise this page won't be build (and will cause a build error). > > You can run `make htmldocs SPHINXDIRS=iio` to speed things up and only build > the iio directory to make sure you have it right. > > More info: https://www.kernel.org/doc/html/latest/doc-guide/sphinx.html > Yes, sorry. > > MAINTAINERS | 1 + > > 2 files changed, 96 insertions(+) > > > > diff --git a/Documentation/iio/ad4052.rst b/Documentation/iio/ad4052.rst > > new file mode 100644 > > index 0000000000000000000000000000000000000000..410aaa437ed5fea6a2924d374fa5f816f5754e22 > > --- /dev/null > > +++ b/Documentation/iio/ad4052.rst > > @@ -0,0 +1,95 @@ > > +.. SPDX-License-Identifier: GPL-2.0-only > > + > > +============= > > +AD4052 driver > > +============= > > + > > +ADC driver for Analog Devices Inc. AD4052 and similar devices. > > Please don't put newline after every period. Here and throughout the document. > It makes it harder to read. > Ack, that was a personal touch that at the time was easier for me to read ahah. Luckly, vim's `gqq` can flawlessly convert. > > +The module name is ``ad4052``. > > + > > +Supported devices > > +================= > > + > > +The following chips are supported by this driver: > > + > > +* `AD4050 <https://www.analog.com/AD4050>`_ > > +* `AD4052 <https://www.analog.com/AD4052>`_ > > +* `AD4056 <https://www.analog.com/AD4056>`_ > > +* `AD4058 <https://www.analog.com/AD4058>`_ > > + > > +Wiring modes > > +============ > > + > > +The ADC uses SPI 4-wire mode, and contain two programmable GPIOs and > > +a CNV pin. > > + > > +The CNV pin is exposed as the ``cnv-gpios`` and triggers a ADC conversion. > > +GP1 is ADC conversion ready signal and GP0 Threshold event interrupt, both > > +exposed as interrupts. > > + > > +Omit ``cnv-gpios`` and tie CNV and CS together to use the rising edge > > +of the CS as the CNV signal. > > + > > +Device attributes > > +================= > > + > > +The ADC contain only one channels, and the following attributes: > > + > > +.. list-table:: Driver attributes > > + :header-rows: 1 > > + > > + * - Attribute > > + - Description > > + * - ``in_voltage0_raw`` > > + - Raw ADC voltage value > > No scale attribute? How do we convert raw to millivolts? > I will add here and to the driver. > > + * - ``in_voltage0_oversampling_ratio`` > > + - Enable the device's burst averaging mode to over sample using > > + the internal sample rate. > > + * - ``in_voltage0_oversampling_ratio_available`` > > + - List of available oversampling values. Value 0 disable the burst > > + averaging mode. > > Typically 1 means no oversampling, not zero. (It is a ratio, divide by 1 is the > same as doing nothing, but divide by 0 is undefined.) > Outdated doc, fixed. > > + * - ``conversion_frequency`` > > Needs to be updated to ``oversampling_frequency``. > Ack. > > + - Device internal sample rate used in the burst averaging mode. > > + * - ``conversion_frequency_available`` > > + - List of available sample rates. > > + > > +Threshold events > > +================ > > + > > +The ADC supports a monitoring mode to raise threshold events. > > +The driver supports a single interrupt for both rising and falling > > +readings. > > + > > +The feature is enabled/disabled by setting ``thresh_either_en``. > > +During monitor mode, the device continuously operates in autonomous mode until > > +put back in configuration mode, due to this, the device returns busy until the > > +feature is disabled. > > Probably worth mentioning the ``events/sampling_frequency`` and > ``sampling_frequency_available`` attributes since we've mentioned all of the > other attributes. > Ack. > > + > > +Low-power mode > > +============== > > + > > +The device enters low-power mode on idle to save power. > > +Enabling an event puts the device out of the low-power since the ADC > > +autonomously samples to assert the event condition. > > + > > +SPI offload support > > +=================== > > + > > +To be able to achieve the maximum sample rate, the driver can be used with the > > +`AXI SPI Engine`_ to provide SPI offload support. > > + > > +.. _AXI SPI Engine: http://analogdevicesinc.github.io/hdl/projects/ad4052_ardz/index.html > > + > > +When SPI offload is being used, additional attributes are present: > > + > > +.. list-table:: Additional attributes > > + :header-rows: 1 > > + > > + * - Attribute > > + - Description > > + * - ``in_voltage0_sampling_frequency`` > > + - Set the sampling frequency. > > + * - ``in_voltage0_sampling_frequency_available`` > > + - Get the sampling frequency range. > > In the driver, this is currently info_mask_shared_by_type, so would be > ``in_voltage_sampling_frequency``. And there currently isn't > ``in_voltage_sampling_frequency_available`` in the driver, so it needs to be > added in the driver (or removed here). Removed here, it is constrained by the PWM trigger. > > > + > > +The scan type is different when the buffer with offload support is enabled. > > diff --git a/MAINTAINERS b/MAINTAINERS > > index 81fbe7176475c48eae03ab04115d4ef5b6299fac..04aa8db44bee418382a2e74cb6b1d03a810bd781 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -1334,6 +1334,7 @@ M: Jorge Marques <jorge.marques@xxxxxxxxxx> > > S: Supported > > W: https://ez.analog.com/linux-software-drivers > > F: Documentation/devicetree/bindings/iio/adc/adi,ad4052.yaml > > +F: Documentation/iio/ad4052.rst > > > > ANALOG DEVICES INC AD4130 DRIVER > > M: Cosmin Tanislav <cosmin.tanislav@xxxxxxxxxx> > > > Sorry about this submission, this file was indeed not updated between version. Regards, Jorge
