diff mbox series

[2/2] doc: iio: ad4695: document buffered read

Message ID 20240807-iio-adc-ad4695-buffered-read-v1-2-bdafc39b2283@baylibre.com (mailing list archive)
State Changes Requested
Headers show
Series iio: adc: ad4695: implement triggered buffer | expand

Commit Message

David Lechner Aug. 7, 2024, 8:02 p.m. UTC
The ad4695 driver has a quirk where the temperature channel can't be
enabled on its own for buffered reads, so we should document this.

Also, since there are 4 possible modes of reading conversion data, it
is useful to know which one is actually being used, namely the advanced
sequencer mode.

Signed-off-by: David Lechner <dlechner@baylibre.com>
---
 Documentation/iio/ad4695.rst | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

Comments

Jonathan Cameron Aug. 10, 2024, 9:36 a.m. UTC | #1
On Wed,  7 Aug 2024 15:02:11 -0500
David Lechner <dlechner@baylibre.com> wrote:

> The ad4695 driver has a quirk where the temperature channel can't be
> enabled on its own for buffered reads, so we should document this.
> 
> Also, since there are 4 possible modes of reading conversion data, it
> is useful to know which one is actually being used, namely the advanced
> sequencer mode.
> 
> Signed-off-by: David Lechner <dlechner@baylibre.com>
> ---
>  Documentation/iio/ad4695.rst | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/iio/ad4695.rst b/Documentation/iio/ad4695.rst
> index a33e573d61d6..af76ce2d0702 100644
> --- a/Documentation/iio/ad4695.rst
> +++ b/Documentation/iio/ad4695.rst
> @@ -147,9 +147,19 @@ Unimplemented features
>  ----------------------
>  
>  - Additional wiring modes
> -- Buffered reads
>  - Threshold events
>  - Oversampling
>  - Gain/offset calibration
>  - GPIO support
>  - CRC support
> +
> +Device buffers
> +==============
> +
> +This driver supports hardware triggered buffers. This uses the "advanced
> +sequencer" feature of the chip to trigger a burst of conversions.
> +
> +Due to hardware constraints, the temperature channel cannot be read on its own
> +for buffered reads. At least one voltage channel must also be enabled.
As per driver review, userspace shouldn't care about that.
We can always read too much and throw the extra away :)

Jonathan

> +
> +Also see :doc:`iio_devbuf` for more general information.
>
diff mbox series

Patch

diff --git a/Documentation/iio/ad4695.rst b/Documentation/iio/ad4695.rst
index a33e573d61d6..af76ce2d0702 100644
--- a/Documentation/iio/ad4695.rst
+++ b/Documentation/iio/ad4695.rst
@@ -147,9 +147,19 @@  Unimplemented features
 ----------------------
 
 - Additional wiring modes
-- Buffered reads
 - Threshold events
 - Oversampling
 - Gain/offset calibration
 - GPIO support
 - CRC support
+
+Device buffers
+==============
+
+This driver supports hardware triggered buffers. This uses the "advanced
+sequencer" feature of the chip to trigger a burst of conversions.
+
+Due to hardware constraints, the temperature channel cannot be read on its own
+for buffered reads. At least one voltage channel must also be enabled.
+
+Also see :doc:`iio_devbuf` for more general information.