From: "Jingoo Han" <jingoohan1@gmail.com> To: 'Pavel Machek' <pavel@ucw.cz>, 'Dan Murphy' <dmurphy@ti.com> Cc: 'Jacek Anaszewski' <jacek.anaszewski@gmail.com>, robh+dt@kernel.org, mark.rutland@arm.com, rpurdie@rpsys.net, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org, 'Lee Jones' <lee.jones@linaro.org>, 'Daniel Thompson' <daniel.thompson@linaro.org> Subject: Re: [PATCH v3 1/2] dt: bindings: lm3692x: Add bindings for lm3692x LED driver Date: Fri, 17 Nov 2017 11:30:09 -0500 [thread overview] Message-ID: <000b01d35fc1$57ad0500$07070f00$@gmail.com> (raw) In-Reply-To: <20171117112032.GA13855@amd> On Friday, November 17, 2017 6:21 AM, Pavel Machek wrote: > > Hi! > > > >> If that does not yet exist... you want to create glue layer to be > able > > >> to use LED as a display backlight. (It may already exist, no idea). > > >> > > >> ... > > >> > > >> Actually or maybe a LED trigger. Just set LED's trigger to "this is > > >> display backlight". > > > > > > There is one already: > > > > > > drivers/leds/trigger/ledtrig-backlight.c > > > > > > It adds a LED class device to the fb_notifier_list > > > (drivers/video/fbdev/core/fb_notify.c) > > > > > > using fb_register_client(). The same is used in > > > backlight_device_register (drivers/video/backlight/backlight.c). > > > > > > Actually why do you want to have this driver in the LED subsystem, > > > if it is advertised as "designed for LCD display backlighting"? > > > > Well this is also advertised as a driver for Smart phone and tablet > devices. And having worked with the Android lighting > > solutions this is the preferred subsystem for Android. The Android OS > manages the led brightness based on ALS values and in > > turn calls into the driver to control the brightness register through > the vendor provided lighting HAL. > > > > Well.. if it can control other LEDs than just backlight, I believe it > can stay in the LED subsystem. I also agree with your opinion. Best regards, Jingoo Han > > > I am going to look at the backlight source to figure out how to get the > same functionality using the backlight subsystem. > > Otherwise I will plug in this driver to the backlight subsystem through > the notifier. > > > > The backlight trigger should be ok. > > Best regards, > Pavel > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) > http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
WARNING: multiple messages have this Message-ID (diff)
From: "Jingoo Han" <jingoohan1@gmail.com> To: "'Pavel Machek'" <pavel@ucw.cz>, "'Dan Murphy'" <dmurphy@ti.com> Cc: "'Jacek Anaszewski'" <jacek.anaszewski@gmail.com>, <robh+dt@kernel.org>, <mark.rutland@arm.com>, <rpurdie@rpsys.net>, <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-leds@vger.kernel.org>, "'Lee Jones'" <lee.jones@linaro.org>, "'Daniel Thompson'" <daniel.thompson@linaro.org> Subject: Re: [PATCH v3 1/2] dt: bindings: lm3692x: Add bindings for lm3692x LED driver Date: Fri, 17 Nov 2017 11:30:09 -0500 [thread overview] Message-ID: <000b01d35fc1$57ad0500$07070f00$@gmail.com> (raw) In-Reply-To: <20171117112032.GA13855@amd> On Friday, November 17, 2017 6:21 AM, Pavel Machek wrote: > > Hi! > > > >> If that does not yet exist... you want to create glue layer to be > able > > >> to use LED as a display backlight. (It may already exist, no idea). > > >> > > >> ... > > >> > > >> Actually or maybe a LED trigger. Just set LED's trigger to "this is > > >> display backlight". > > > > > > There is one already: > > > > > > drivers/leds/trigger/ledtrig-backlight.c > > > > > > It adds a LED class device to the fb_notifier_list > > > (drivers/video/fbdev/core/fb_notify.c) > > > > > > using fb_register_client(). The same is used in > > > backlight_device_register (drivers/video/backlight/backlight.c). > > > > > > Actually why do you want to have this driver in the LED subsystem, > > > if it is advertised as "designed for LCD display backlighting"? > > > > Well this is also advertised as a driver for Smart phone and tablet > devices. And having worked with the Android lighting > > solutions this is the preferred subsystem for Android. The Android OS > manages the led brightness based on ALS values and in > > turn calls into the driver to control the brightness register through > the vendor provided lighting HAL. > > > > Well.. if it can control other LEDs than just backlight, I believe it > can stay in the LED subsystem. I also agree with your opinion. Best regards, Jingoo Han > > > I am going to look at the backlight source to figure out how to get the > same functionality using the backlight subsystem. > > Otherwise I will plug in this driver to the backlight subsystem through > the notifier. > > > > The backlight trigger should be ok. > > Best regards, > Pavel > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) > http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
next prev parent reply other threads:[~2017-11-17 16:30 UTC|newest] Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-11-15 19:42 [PATCH v3 1/2] dt: bindings: lm3692x: Add bindings for lm3692x LED driver Dan Murphy 2017-11-15 19:42 ` Dan Murphy [not found] ` <20171115194203.13572-1-dmurphy-l0cyMroinI0@public.gmane.org> 2017-11-15 19:42 ` [PATCH v3 2/2] leds: lm3692x: Introduce LM3692x dual string driver Dan Murphy 2017-11-15 19:42 ` Dan Murphy [not found] ` <20171115194203.13572-2-dmurphy-l0cyMroinI0@public.gmane.org> 2017-11-15 21:12 ` Pavel Machek 2017-11-15 21:12 ` Pavel Machek 2017-11-15 21:25 ` Dan Murphy 2017-11-15 21:25 ` Dan Murphy 2017-11-18 14:19 ` Jacek Anaszewski 2017-11-18 14:19 ` Jacek Anaszewski 2017-11-28 12:53 ` Dan Murphy 2017-11-28 12:53 ` Dan Murphy 2017-11-15 20:15 ` [PATCH v3 1/2] dt: bindings: lm3692x: Add bindings for lm3692x LED driver Jacek Anaszewski 2017-11-15 20:15 ` Jacek Anaszewski [not found] ` <cb5c5a65-d5a0-86a3-36b4-cf06baae9ec4-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> 2017-11-15 20:31 ` Dan Murphy 2017-11-15 20:31 ` Dan Murphy [not found] ` <0a78c883-f074-cc19-3c0c-fc05607400e9-l0cyMroinI0@public.gmane.org> 2017-11-15 22:23 ` Pavel Machek 2017-11-15 22:23 ` Pavel Machek 2017-11-16 20:14 ` Jacek Anaszewski [not found] ` <82336eb7-2b89-d37b-d688-4e4302766346-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> 2017-11-16 21:42 ` Dan Murphy 2017-11-16 21:42 ` Dan Murphy 2017-11-17 2:19 ` Jingoo Han 2017-11-17 2:19 ` Jingoo Han 2017-11-17 11:20 ` Pavel Machek 2017-11-17 16:30 ` Jingoo Han [this message] 2017-11-17 16:30 ` Jingoo Han 2017-11-17 18:02 ` Dan Murphy 2017-11-17 18:02 ` Dan Murphy 2017-11-17 23:58 ` Pavel Machek 2017-11-28 17:27 ` Dan Murphy 2017-11-28 17:27 ` Dan Murphy 2017-11-16 15:41 ` Rob Herring 2017-11-16 15:41 ` Rob Herring 2017-11-16 15:45 ` Dan Murphy 2017-11-16 15:45 ` Dan Murphy [not found] ` <d3483e49-650d-1d68-bec6-eeb84d8ac48a-l0cyMroinI0@public.gmane.org> 2017-11-16 15:58 ` Rob Herring 2017-11-16 15:58 ` Rob Herring 2017-11-16 20:11 ` dts: fun with chip names " Pavel Machek 2017-11-16 20:36 ` Rob Herring [not found] ` <CAL_Jsq+aysVR9U2Wquwwv7cjjO7wO8EXBg1Ja82u6s5t1yeJUw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2017-11-16 21:40 ` Dan Murphy 2017-11-16 21:40 ` Dan Murphy 2017-11-18 14:19 ` Jacek Anaszewski
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