2020-09-18 11:33:35

by Cristian Pop

Subject: [PATCH v5] iio:Documentation: Add documentation for label channel attribute

If a label is defined in the device tree for this channel add that to the
channel specific attributes. This is useful for userspace to be able to
identify an individual channel.

Signed-off-by: Cristian Pop <[email protected]>
---
Changes in V5:
Create a separate patch file for this commit.
Documentation/ABI/testing/sysfs-bus-iio | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index d3e53a6d8331..f2a9a03b8af9 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -1697,6 +1697,15 @@ Description:

Raw counter device counters direction for channel Y.

+What: /sys/bus/iio/devices/iio:deviceX/channel_label
+KernelVersion: 5.8
+Contact: [email protected]
+Description:
+ Optional symbolic label to a device channel.
+ If a label is defined in the device tree for this channel add
+ that to the channel specific attributes. This is useful for
+ userspace to be able to identify an individual channel.
+
What: /sys/bus/iio/devices/iio:deviceX/in_phaseY_raw
KernelVersion: 4.18
Contact: [email protected]
--
2.17.1

2020-09-19 15:25:12

by Jonathan Cameron

Subject: Re: [PATCH v5] iio:Documentation: Add documentation for label channel attribute

On Fri, 18 Sep 2020 12:33:37 +0300
Cristian Pop <[email protected]> wrote:

> If a label is defined in the device tree for this channel add that to the
> channel specific attributes. This is useful for userspace to be able to
> identify an individual channel.
>
> Signed-off-by: Cristian Pop <[email protected]>
> ---
> Changes in V5:
> Create a separate patch file for this commit.
> Documentation/ABI/testing/sysfs-bus-iio | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
> index d3e53a6d8331..f2a9a03b8af9 100644
> --- a/Documentation/ABI/testing/sysfs-bus-iio
> +++ b/Documentation/ABI/testing/sysfs-bus-iio
> @@ -1697,6 +1697,15 @@ Description:
>
> Raw counter device counters direction for channel Y.
>
> +What: /sys/bus/iio/devices/iio:deviceX/channel_label

That naming doesn't look right. Should be something like
in_voltageY_label

> +KernelVersion: 5.8
> +Contact: [email protected]
> +Description:
> + Optional symbolic label to a device channel.
> + If a label is defined in the device tree for this channel add
> + that to the channel specific attributes. This is useful for
> + userspace to be able to identify an individual channel.

This isn't devicetree specific. The driver can elect to provide this
label from all sorts of sources such as ACPI, or it might be hard coded
in the driver if the channel is internal to a SoC for example.

> +
> What: /sys/bus/iio/devices/iio:deviceX/in_phaseY_raw
> KernelVersion: 4.18
> Contact: [email protected]