lkml.org 
[lkml]   [2019]   [Jul]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 3/4] backlight: add led-backlight driver
From
Date
Pavel

On 05/07/2019 12:08, Pavel Machek wrote:
> Hi!
>
>>>>> Also still relevant is whether the LED device is being correctly
>>>>> modelled if the act of turning on the LED doesn't, in fact, turn the LED
>>>>> on. Is it *really* a correct implementation of an LED device that
>>>>> setting it to LED_FULL using sysfs doesn't cause it to light up?
>>>> What I understood from the discussion between Rob and Tomi is that the
>>>> child-node of the LED controller should be considered a backlight device,
>>>> not a simple LED. I'm not sure if the sysfs interface is still relevant in
>>>> that case. Maybe it should just be disabled by the backlight driver
>>>> (possible with led_sysfs_disable())
>>> led_sysfs_disable() sounds like a sensible change but that's not quite
>>> what I mean.
>>>
>>> It is more a thought experiment to see if the power control *should* be
>>> implemented by the backlight. Consider what happens if we *don't*
>>> enable CONFIG_BACKLIGHT_LED in the kernel: we would still have an LED
>>> device and it would not work correctly.
>>>
>>> In other words I naively expect turning on an LED using the LED API
>>> (any of them, sysfs or kernel) to result in the LED turning on.
>>> Implementing a workaround in the client for what appears to be
>>> something missing in the LED driver strikes me as odd. Why shouldn't
>>> the regulator be managed in the LED driver?
>> I see your point. Indeed having the regulator handled in the LED-core makes
>> sense in a lot of situations
>>
>> I'll think about it.
> For the record, I also believe regulator and enable gpio should be
> handled in the core.

I am working on adding the regulator to the led core.

I don't really want to add a GPIO enable to the core though. If needed
it can be described as a GPIO-enabled regulator up(/down)stream the
regular regulator.

JJ


>
> Pavel
> PS please trim down the quoted text.

\
 
 \ /
  Last update: 2019-07-05 12:34    [W:0.070 / U:0.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site