Hi Rafał,
On 01/20/2017 10:56 PM, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal@xxxxxxxxxx>
>
> Some LEDs can be related to particular devices described in DT. This
> property allows specifying such relations. E.g. USB LED should usually
> be used to indicate some USB port(s) state.
>
> Signed-off-by: Rafał Miłecki <rafal@xxxxxxxxxx>
> ---
> V2: Replace "usb-ports" with "led-triggers" property which is more generic and
> allows specifying other devices as well.
>
> When bindings patch is related to some followup implementation, they usually go
> through the same tree.
>
> Greg: this patch is based on top of e64b8cc72bf9 ("DT: leds: Improve examples by
> adding some context") from kernel/git/j.anaszewski/linux-leds.git . Is there any
> way to solve this dependency issue? Or should this patch wait until 3.11 is
> released?
> ---
> Documentation/devicetree/bindings/leds/common.txt | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/leds/common.txt b/Documentation/devicetree/bindings/leds/common.txt
> index 24b656014089..17632a041196 100644
> --- a/Documentation/devicetree/bindings/leds/common.txt
> +++ b/Documentation/devicetree/bindings/leds/common.txt
> @@ -49,6 +49,17 @@ Optional properties for child nodes:
> - panic-indicator : This property specifies that the LED should be used,
> if at all possible, as a panic indicator.
>
> +- led-triggers : List of devices that should trigger this LED activity. Some
> + LEDs can be related to a specific device and should somehow
> + indicate its state. E.g. USB 2.0 LED may react to device(s) in
> + a USB 2.0 port(s). Another common example is switch or router
> + with multiple Ethernet ports each of them having its own LED
> + assigned (assuminled-trigger-usbportg they are not hardwired).
> + In such cases this property should contain phandle(s) of
> + related device(s). In many cases LED can be related to more
> + than one device (e.g. one USB LED vs. multiple USB ports) so a
> + list of entries can be specified.
> +
This implies that it is possible to define multiple triggers for
a LED class device but it is not supported by LED Trigger core.
There is linux,default-trigger property which allows to define one
trigger that will be initially assigned.
I am aware that this is renamed usb-ports property from v1,
that attempts to address Rob's comment, but we can't do that this way.
Maybe usb-ports property could be documented in led-trigger-usbport's
specific bindings and a reference to it could be added next to the
related entry on the list of the available LED triggers (which is
actually missing) in Documentation/devicetree/bindings/leds/common.txt.
> Required properties for flash LED child nodes:
> - flash-max-microamp : Maximum flash LED supply current in microamperes.
> - flash-max-timeout-us : Maximum timeout in microseconds after which the flash
> @@ -69,6 +80,11 @@ gpio-leds {
> linux,default-trigger = "heartbeat";
> gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>;
> };
> +
> + usb {
> + gpios = <&gpio0 1 GPIO_ACTIVE_HIGH>;
> + led-triggers = <&ohci_port1>, <&ehci_port1>;
> + };
> };
>
> max77693-led {
>
--
Best regards,
Jacek Anaszewski
