Messages in this thread | | | Date | Mon, 12 Jan 2015 17:10:23 +0100 | From | Jacek Anaszewski <> | Subject | Re: [PATCH/RFC v10 03/19] DT: leds: Add led-sources property |
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On 01/12/2015 02:52 PM, Rob Herring wrote: > On Mon, Jan 12, 2015 at 2:32 AM, Jacek Anaszewski > <j.anaszewski@samsung.com> wrote: >> On 01/09/2015 07:33 PM, Rob Herring wrote: >>> >>> On Fri, Jan 9, 2015 at 9:22 AM, Jacek Anaszewski >>> <j.anaszewski@samsung.com> wrote: >>>> >>>> Add a property for defining the device outputs the LED >>>> represented by the DT child node is connected to. >>>> >>>> Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> >>>> Acked-by: Kyungmin Park <kyungmin.park@samsung.com> >>>> Cc: Bryan Wu <cooloney@gmail.com> >>>> Cc: Richard Purdie <rpurdie@rpsys.net> >>>> Cc: Rob Herring <robh+dt@kernel.org> >>>> Cc: Pawel Moll <pawel.moll@arm.com> >>>> Cc: Mark Rutland <mark.rutland@arm.com> >>>> Cc: Ian Campbell <ijc+devicetree@hellion.org.uk> >>>> Cc: Kumar Gala <galak@codeaurora.org> >>>> --- >>>> Documentation/devicetree/bindings/leds/common.txt | 5 +++++ >>>> 1 file changed, 5 insertions(+) >>>> >>>> diff --git a/Documentation/devicetree/bindings/leds/common.txt >>>> b/Documentation/devicetree/bindings/leds/common.txt >>>> index a2c3f7a..29295bf 100644 >>>> --- a/Documentation/devicetree/bindings/leds/common.txt >>>> +++ b/Documentation/devicetree/bindings/leds/common.txt >>>> @@ -1,6 +1,10 @@ >>>> Common leds properties. >>>> >>>> Optional properties for child nodes: >>>> +- led-sources : Array of bits signifying the LED current regulator >>>> outputs the >>>> + LED represented by the child node is connected to (1 - >>>> the LED >>>> + is connected to the output, 0 - the LED isn't connected >>>> to the >>>> + output). >>> >>> >>> Sorry, I just don't understand this. >> >> >> In some Flash LED devices one LED can be connected to one or more >> electric current outputs, which allows for multiplying the maximum >> current allowed for the LED. Each sub-LED is represented by a child >> node in the DT binding of the Flash LED device and it needs to declare >> which outputs it is connected to. In the example below the led-sources >> property is a two element array, which means that the flash LED device >> has two current outputs, and the bits signify if the LED is connected >> to the output. > > Sounds like a regulator for which we already have bindings for and we > have a driver for regulator based LEDs (but no binding for it).
Do you think of drivers/leds/leds-regulator.c driver? This driver just allows for registering an arbitrary regulator device as a LED subsystem device.
There are however devices that don't fall into this category, i.e. they have many outputs, that can be connected to a single LED or to many LEDs and the driver has to know what is the actual arrangement.
> Please use the regulator binding.
>> Do your doubts stem from the ambiguity of the word "current" or the >> form of the description itself is unclear? Probably there should be >> explicit explanation added that the size of the array depends on the >> number of current outputs of the flash LED device. > > The size of the array and meaning of array indexes was not clear.
What about this:
led-sources : Array of connection states between all LED current sources exposed by the device and this LED (1 - this LED is connected to the current output with index N, 0 - this LED isn't connected to the current output with index N); the mapping of N-th element of the array to the physical device output should be defined in the LED driver binding.
-- Best Regards, Jacek Anaszewski
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