Re: [PATCH v2 9/9] iio: ABI: add DAC sysfs synchronous_mode parameter
From: David Lechner
Date: Thu Sep 05 2024 - 15:14:52 EST
On 9/5/24 10:17 AM, Angelo Dureghello wrote:
> From: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
>
> Some DACs as ad3552r need a synchronous mode setting, adding
> this parameter for ad3552r and for future use on other DACs,
> if needed.
>
> Signed-off-by: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
> ---
> Documentation/ABI/testing/sysfs-bus-iio-dac | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio-dac b/Documentation/ABI/testing/sysfs-bus-iio-dac
> index 810eaac5533c..2f4960c79385 100644
> --- a/Documentation/ABI/testing/sysfs-bus-iio-dac
> +++ b/Documentation/ABI/testing/sysfs-bus-iio-dac
> @@ -59,3 +59,19 @@ Description:
> multiple predefined symbols. Each symbol corresponds to a different
> output, denoted as out_voltageY_rawN, where N is the integer value
> of the symbol. Writing an integer value N will select out_voltageY_rawN.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/out_voltage_synchronous_mode
> +KernelVersion: 6.13
> +Contact: linux-iio@xxxxxxxxxxxxxxx
> +Description:
> + Arm or disarm a wait-for-synchronization flag. Arming this flag
> + means the DAC will wait for a synchronizatiopn signal on a
> + specific internal or external wired connection. I.e., there are
> + cases where multiple DACs IP are built in the same chip or fpga
> + design, and they need to start the data stream synchronized.
> +
> +What: /sys/bus/iio/devices/iio:deviceX/out_voltage_synchronous_mode_available
> +KernelVersion: 6.13
> +Contact: linux-iio@xxxxxxxxxxxxxxx
> +Description:
> + List of available values for synchronous_mode.
>
Since this depends on how things are wired, it seems like this should be
something specified in the devicetree, not through sysfs attributes.