Hi Jean, Side note: please use plain text in your messages. On 6/27/19 3:14 PM, Jean-Jacques Hiblot wrote: > Hi Jacek, > > On 26/06/2019 20:55, Jacek Anaszewski wrote: >> Hi Jean, >> >> On 6/26/19 5:34 PM, Jean-Jacques Hiblot wrote: >>> 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>; > }; > }; > >> Regarding the bindings we have pending LED naming patch set, >> that deprecates DT label property [0] and introduces standardized >> LED functions. >> >> [0] https://lkml.org/lkml/2019/6/9/728 > > Thanks for the info. > >
