Messages in this thread | | | Subject | Re: [RFC PATCH v4 2/8] leds: document additional use of blink_set for hardware control | From | Randy Dunlap <> | Date | Wed, 10 Nov 2021 18:28:09 -0800 |
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Hi Ansuel,
Sorry -- I screwed this one up a little bit on the previous iteration.
On 11/10/21 5:34 PM, Ansuel Smith wrote: > diff --git a/Documentation/leds/leds-class.rst b/Documentation/leds/leds-class.rst > index 0175954717a3..c06a18b811de 100644 > --- a/Documentation/leds/leds-class.rst > +++ b/Documentation/leds/leds-class.rst > @@ -202,6 +202,23 @@ hardware mode and any software only trigger will reject activation. > On init a LED driver that support a hardware mode should reset every blink mode > set by default. > > +Once a trigger has declared support for hardware-controller blinks, it will use
hardware-controlled
> +blink_set() to try to offload his trigger on activation/configuration. > +blink_set() will return 0 if the requested modes set in trigger_data can be > +controlled by hardware or an error if both the mode bitmap is not supported by
maybe: if both of the bitmap modes are not supported by
> +the hardware or there was a problem in the configuration. > + > +Following blink_set logic, setting brightness to LED_OFF with hardware control active > +will reset any active blink mode and disable hardware control setting the LED to off. > + > +It's in the LED driver's interest to know how to elaborate the trigger data and report support > +for a particular set of blink modes. For this exact reason explicit support for the specific > +trigger is mandatory or the driver returns -EOPNOTSUPP if asked to enter hardware mode > +with a not supported trigger. > +If the driver returns -EOPNOTSUPP on hw_control_configure(), the trigger activation will > +fail as the driver doesn't support that specific hardware blink modes or doesn't know
mode
> +how to handle the provided trigger data.
thanks. -- ~Randy
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