From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Date: Thu, 15 Oct 2015 12:17:37 +0000 Subject: Re: [PATCHv4 3/3] devicetree: Add led-backlight binding Message-Id: <561F9961.30008@ti.com> MIME-Version: 1 Content-Type: multipart/mixed; boundary="ocAEPGIkEoUlbm8Jm3t64DEjfg6r2LfGd" List-Id: References: <1443605522-1118-1-git-send-email-tomi.valkeinen@ti.com> <1443605522-1118-4-git-send-email-tomi.valkeinen@ti.com> In-Reply-To: To: Rob Herring Cc: Jacek Anaszewski , Jingoo Han , Lee Jones , Linux LED Subsystem , "linux-fbdev@vger.kernel.org" , Andrew Lunn , "devicetree@vger.kernel.org" --ocAEPGIkEoUlbm8Jm3t64DEjfg6r2LfGd Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Hi Rob, On 13/10/15 17:21, Rob Herring wrote: > On Wed, Sep 30, 2015 at 4:32 AM, Tomi Valkeinen = wrote: >> Add DT binding for led-backlight. >=20 > Please use get_maintainers.pl. At some point I got feedback that the DT maintainers don't have time to look at each individual driver binding, but rely on the subsystem maintainers to handle them. Maybe I misunderstood that. >> Signed-off-by: Tomi Valkeinen >> Cc: devicetree@vger.kernel.org >> --- >> .../bindings/video/backlight/led-backlight.txt | 30 +++++++++++++= +++++++++ >> 1 file changed, 30 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/video/backlight/= led-backlight.txt >> >> diff --git a/Documentation/devicetree/bindings/video/backlight/led-bac= klight.txt b/Documentation/devicetree/bindings/video/backlight/led-backli= ght.txt >> new file mode 100644 >> index 000000000000..d4621d7414bc >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/video/backlight/led-backlight.= txt >> @@ -0,0 +1,30 @@ >> +led-backlight bindings >> + >> +Required properties: >> + - compatible: "led-backlight" >> + - leds: phandle to a led OF node [0] >=20 > Why do we need 2 levels of LED nodes? Sorry, didn't get that. What do you mean with 2 levels? >> + - brightness-levels: Array of distinct LED brightness levels. These= >> + are in the range from 0 to 255, passed to the LED class driver.= >> + - default-brightness-level: the default brightness level (index int= o the >> + array defined by the "brightness-levels" property) >> + >> +Optional properties: >> + - power-supply: regulator for supply voltage >> + - enable-gpios: contains a single GPIO specifier for the GPIO which= enables >> + and disables the backlight (see GPIO binding[1]) >=20 > Why are all of these not part of the LED node pointed to by leds? These are for the backlight, not for the LED chip. So "LED" here is a chip that produces (most likely) a PWM signal, and "backlight" is the collection of components that use the PWM to produce the backlight itself, and use the power-supply and gpios. > Describe the h/w, not what you want for a driver. I think this describes the HW quite well. The LED chip works fine without any of the properties here, and these are specific to the backlight part of the board. Tomi --ocAEPGIkEoUlbm8Jm3t64DEjfg6r2LfGd Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJWH5liAAoJEPo9qoy8lh71RIMP/3JYbLaSpte3AzUOm0lKQT/D gdys+5G1PRQjJvlmdN3LwxiCCRJMPg4OK2Mivm5SQYJ7TDMsipnqJ6qq+ZWV0Y0b EfMNxL7HLEF/JAaL+HtqGA+GERXmfpoMfzeEIfZ6fUsTd6HrJdeupkVfRX38KlMn ccmsu6cUnF3ZxQMvAZWiPTMNx/abuXZX466H5wQ/OHxUYvYKblrwX/etD0OrWpcx iLXg4DjX9mzqybrxeOOotd/Uh70AoXBKuELRMT/RSunfIdPQCHb6QyG3Gq9QUeta F7CjaifoU+Pj1puVYgqyIs0WqwZDWSq5b0gVZq4hNum8BVVqsCiwhkI8uFDaDsHc osZvni6jYBhZ3IlLLBcLAAMTPrUR/IA4wT73qpxeWqa8dEKygGwQM9vesQBj6I6y vmcRejxt617c8EyK22xMh9pik7INEQjYqAPxWeYOYWLlb3uldRJ+cDxQLSVSu4ns yFmKUAwdDzH5Guifpd2dFWK7QtOsgyxJkScQg+2N8r0FygCUw1Q9XJ9Itp/JDYsl FP3H1o9+/iO3qJ3a4G5wZkKbPtVmJumkhsfnxFyCxetsSv1u75Ugc44Mn7bXLn5n ROjC9qHbrMBM7Dsbev0xw6fTWqvh6BJP6JKyE61roalUoUBx2q412Osroo5hBWep xkojurpH5azy1B12Gcjp =Gnho -----END PGP SIGNATURE----- --ocAEPGIkEoUlbm8Jm3t64DEjfg6r2LfGd--