Re: [PATCH V3] led: Backlight trigger for led subsystem

From: Pavel Machek
Date: Tue Oct 07 2008 - 17:17:49 EST


On Tue 2008-10-07 21:39:46, Mark Brown wrote:
> On Tue, Oct 07, 2008 at 10:19:54PM +0200, Rodolfo Giometti wrote:
> > On Tue, Oct 07, 2008 at 09:56:48PM +0200, Pavel Machek wrote:
>
> > > Hmm, what's "your board"?
>
> > Sorry, I meant "my custom board". :) It's PXA270 based but it's not
> > into Linux main tree.
>
> Another example, support for which should be coming shortly, is the LED
> driver provided by the WM8350: this is a PMIC capable of producing outputs
> to drive LEDs, potentially strings of very bright LEDs. This is frequently
> used to illuminate displays but the actual function depends entirely on how
> the system has been wired up.
>
> The implementation is identical no matter what the LEDs are doing but the
> current out of tree drivers have two drivers for this bit of the hardware,
> one for use in the normal LED case and one for when used as a backlight,
> which is redundnant. With the driver Rodolfo has written this should no
> longer be required and the backlight trigger can be used to share the
> hardware interface code.

Well, Rodolfo's patch will not allow you to set backlight brightness,
only on/off, right?

So if your leds are really a backlight, you still should use backlight
class directly...
Pavel
--
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