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([2600:8803:e7e4:500:b75d:2440:dc10:808b]) by smtp.gmail.com with ESMTPSA id 46e09a7af769-7dc26941b7esm2736484a34.19.2026.04.10.14.38.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 10 Apr 2026 14:38:49 -0700 (PDT) Message-ID: <9c36ee85-12da-41e8-b9ab-e32b7ec29e75@baylibre.com> Date: Fri, 10 Apr 2026 16:38:48 -0500 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7 6/6] docs: iio: adc: ad4691: add driver documentation To: radu.sabau@analog.com, Lars-Peter Clausen , Michael Hennerich , Jonathan Cameron , =?UTF-8?Q?Nuno_S=C3=A1?= , Andy Shevchenko , Rob Herring , Krzysztof Kozlowski , Conor Dooley , =?UTF-8?Q?Uwe_Kleine-K=C3=B6nig?= , Liam Girdwood , Mark Brown , Linus Walleij , Bartosz Golaszewski , Philipp Zabel , Jonathan Corbet , Shuah Khan Cc: linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pwm@vger.kernel.org, linux-gpio@vger.kernel.org, linux-doc@vger.kernel.org References: <20260409-ad4692-multichannel-sar-adc-driver-v7-0-be375d4df2c5@analog.com> <20260409-ad4692-multichannel-sar-adc-driver-v7-6-be375d4df2c5@analog.com> Content-Language: en-US From: David Lechner In-Reply-To: <20260409-ad4692-multichannel-sar-adc-driver-v7-6-be375d4df2c5@analog.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/9/26 10:28 AM, Radu Sabau via B4 Relay wrote: > From: Radu Sabau > > Add RST documentation for the AD4691 family ADC driver covering > supported devices, IIO channels, operating modes, oversampling, > reference voltage, LDO supply, reset, GP pins, SPI offload support, > and buffer data format. > > Signed-off-by: Radu Sabau > --- > Documentation/iio/ad4691.rst | 283 +++++++++++++++++++++++++++++++++++++++++++ > Documentation/iio/index.rst | 1 + > MAINTAINERS | 1 + > 3 files changed, 285 insertions(+) > > diff --git a/Documentation/iio/ad4691.rst b/Documentation/iio/ad4691.rst > new file mode 100644 > index 000000000000..a1012c8b78a3 > --- /dev/null > +++ b/Documentation/iio/ad4691.rst > @@ -0,0 +1,283 @@ > +.. SPDX-License-Identifier: GPL-2.0-only > + > +============= > +AD4691 driver > +============= One overall comment. This goes into driver implementation details quite a bit. I think that is really better done as comments in the driver itself. And this document should just focus on how to use the driver from the userspace point of view. > +Buffer data format > +================== > + > +The IIO buffer data format (``in_voltageN_type``) is the same across all > +paths: 16-bit unsigned big-endian samples with no shift. > + > ++-------------------------+-------------+----------+-------+ > +| Path | storagebits | realbits | shift | > ++=========================+=============+==========+=======+ > +| Triggered buffer | 16 | 16 | 0 | > ++-------------------------+-------------+----------+-------+ > +| CNV Burst offload (DMA) | 16 | 16 | 0 | > ++-------------------------+-------------+----------+-------+ > +| Manual offload (DMA) | 16 | 16 | 0 | > ++-------------------------+-------------+----------+-------+ Not sure this table is helpful since all values are the same everywhere. Also, doesn't SPI offload have storagebits == 32? > + > +In the triggered-buffer path the SPI rx_buf for each transfer points directly > +into the scan buffer, so the 16-bit big-endian result is written in place with > +no additional copying. > +