Hi! > >>> A few years ago (2015), Tomi Valkeinen posted a series implementing a > >>> backlight driver on top of a LED device. > >>> > >>> https://patchwork.kernel.org/patch/7293991/ > >>> https://patchwork.kernel.org/patch/7294001/ > >>> https://patchwork.kernel.org/patch/7293981/ > >>> > >>> The discussion stopped because he lacked the time to work on it. > >>> > >>> I will be taking over the task and, before heading in the wrong > >>> direction, wanted a confirmation that the binding Tomi last proposed in > >>> hist last email was indeed the preferred option. > >>> > >>> It will probably require some modifications in the LED core to create > >>> the right kind of led-device (normal, flash or backlight) based on the > >>> compatible option. > >> I recall that discussion. I gave my ack for the LED changes but > >> now we have more LED people that might want to look into that. > > > > Regarding the LED bindings as discussed by Tom and Rob in > > https://patchwork.kernel.org/patch/7293991/, what do you think of using > > a 'compatible' string to make a LED device also a backlight or a flash LED ? > > After going through the referenced discussion and refreshing my memory > it looks to me the most reasonable way to go for backlight case. > > Nevertheless I'd not tamper at LED flash support - if it's not broken, > don't fix it. > > Best regards, > Jacek Anaszewski > > > Here is the example from Tomi at the end of the discussion: > > > > /* tlc59108 is an i2c device */ > > tlc59116@40 { > > #address-cells = <1>; > > #size-cells = <0>; > > compatible = "ti,tlc59108"; > > reg = <0x40>; > > > > wan@0 { > > label = "wrt1900ac:amber:wan"; > > reg = <0x0>; > > }; > > > > bl@2 { > > label = "backlight"; > > reg = <0x2>; > > > > compatible = "led-backlight"; > > brightness-levels = <0 243 245 247 248 249 251 252 255>; > > default-brightness-level = <8>; > > > > enable-gpios = <&pcf_lcd 13 GPIO_ACTIVE_LOW>; So... this needs some kind of reference to display it belongs to, right? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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