linux-kernel - Re: [PATCH/RFC v10 03/19] DT: leds: Add led-sources property

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 12 Jan 2015 07:52:24 -0600
From:	Rob Herring <robherring2@...il.com>
To:	Jacek Anaszewski <j.anaszewski@...sung.com>
Cc:	linux-leds@...r.kernel.org,
	"linux-media@...r.kernel.org" <linux-media@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	Kyungmin Park <kyungmin.park@...sung.com>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
	Pavel Machek <pavel@....cz>, Bryan Wu <cooloney@...il.com>,
	Richard Purdie <rpurdie@...ys.net>, sakari.ailus@....fi,
	Sylwester Nawrocki <s.nawrocki@...sung.com>,
	Rob Herring <robh+dt@...nel.org>,
	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>
Subject: Re: [PATCH/RFC v10 03/19] DT: leds: Add led-sources property

On Mon, Jan 12, 2015 at 2:32 AM, Jacek Anaszewski
<j.anaszewski@...sung.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@...sung.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@...sung.com>
>>> Acked-by: Kyungmin Park <kyungmin.park@...sung.com>
>>> Cc: Bryan Wu <cooloney@...il.com>
>>> Cc: Richard Purdie <rpurdie@...ys.net>
>>> Cc: Rob Herring <robh+dt@...nel.org>
>>> Cc: Pawel Moll <pawel.moll@....com>
>>> Cc: Mark Rutland <mark.rutland@....com>
>>> Cc: Ian Campbell <ijc+devicetree@...lion.org.uk>
>>> Cc: Kumar Gala <galak@...eaurora.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). 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.

Rob

>
>
>>>   - label : The label for this LED.  If omitted, the label is
>>>     taken from the node name (excluding the unit address).
>>>
>>> @@ -33,6 +37,7 @@ system-status {
>>>
>>>   camera-flash {
>>>          label = "Flash";
>>> +       led-sources = <1 0>;
>>>          max-microamp = <50000>;
>>>          flash-max-microamp = <320000>;
>>>          flash-timeout-us = <500000>;
>>> --
>>> 1.7.9.5
>>>
>>
>
> --
> Best Regards,
> Jacek Anaszewski
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/