From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [PATCH v2 07/19] tegra: fdt: Add LCD definitions for Tegra Date: Thu, 12 Jul 2012 10:40:51 +0200 Message-ID: <20120712084051.GA27022@avionic-0098.adnet.avionic-design.de> References: <1339604395-6621-1-git-send-email-sjg@chromium.org> <1339604395-6621-8-git-send-email-sjg@chromium.org> <4FDA749D.2030201@wwwdotorg.org> <20120711054842.GB10344@avionic-0098.mockup.avionic-design.de> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1986883763==" Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: u-boot-bounces@lists.denx.de Errors-To: u-boot-bounces@lists.denx.de To: Simon Glass Cc: Stephen Warren , Devicetree Discuss , U-Boot Mailing List , Jerry Van Baren , Alex Courbot , Tom Warren List-Id: devicetree@vger.kernel.org --===============1986883763== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="TB36FDmn/VVEgNH/" Content-Disposition: inline --TB36FDmn/VVEgNH/ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jul 12, 2012 at 10:21:01AM +0200, Simon Glass wrote: > Hi Thierry, >=20 > On Wed, Jul 11, 2012 at 7:48 AM, Thierry Reding > wrote: > > On Wed, Jul 11, 2012 at 06:44:10AM +0200, Simon Glass wrote: > >> Hi Stephen, > >> > >> On Fri, Jun 15, 2012 at 1:32 AM, Stephen Warren wrote: > >> > >> > On 06/13/2012 10:19 AM, Simon Glass wrote: > >> > > Add LCD definitions and also a proposed binding for LCD displays. > >> > > > >> > > The PWFM is in progress on the device-tree-discuss list, so only a > >> > > very basic binding is offered here. > >> > > >> > I believe we have settled on a final representation, it just hasn't = been > >> > added into linux-next yet. See: > >> > > >> > > >> > http://gitorious.org/linux-pwm/linux-pwm/commit/d3ce73e5dc86646a6302= f2b0f7dd40e8c552fa04 > >> > >> > >> Thanks for the pointer. I suppose this doesn't address clocks as yet, = but > >> that's fine. > > > > I was waiting for the common clock framework and DT bindings to get > > ready. This should happen RSN for Tegra so I will probably look at > > adding support for it in. >=20 > OK, are you looking at adding it in U-Boot? No. I don't have much time to spend on U-Boot right now. [...] > I also need a place to put the pwm and GPIOs for the panel itself. > Something like this: >=20 > nvidia,pwm =3D <&pwm 2 0>; > nvidia,backlight-enable-gpios =3D <&gpio 28 0>; /* PD4 */ > nvidia,lvds-shutdown-gpios =3D <&gpio 10 0>; /* PB2 */ > nvidia,backlight-vdd-gpios =3D <&gpio 176 0>; /* PW0 */ > nvidia,panel-vdd-gpios =3D <&gpio 22 0>; /* PC6 */ > nvidia,panel-timings =3D <4 203 17 15>; (number of ms before turning > on the next gpio) > nvidia,bits-per-pixel =3D <16>; (er, TBD) >=20 > I am thinking of something like a phandle in your rgb node: >=20 > host1x { > dc@54200000 { > rgb { > nvidia-panel =3D <&lcd_panel>; > ... >=20 > lcd_panel: panel { > nvidia,pwm =3D <&pwm 2 0>; > ... > } >=20 > Or have you already solved this problem another way? Linux has a generic PWM backlight driver. This is currently solved by using this in the DT: backlight { compatible =3D "pwm-backlight"; pwms =3D <&pwm 0 5000000>; brightness-levels =3D <0 4 8 16 32 64 128 255>; default-brightness-level =3D <6>; }; Alex Courbot (Cc'd) has been working on adding a generic way to add GPIO and regulator support to that. I don't know exactly what the lvds-shutdown-gpios and panel-vdd-gpios properties do. If they control hardware connected behind the display controller I suppose they could go into the rgb node. The panel alternative that you propose sounds interesting as well. Maybe the panel should itself contain either a phandle or a subnode for the backlight and collect the properties that you listed above. Thierry --TB36FDmn/VVEgNH/ Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iQIcBAEBAgAGBQJP/o2TAAoJEN0jrNd/PrOhgVIQAL7uoA315D0ojVd5SUNq06q9 PaPqrKgoZhaGmty0AB59A7C0OTJnHi7o5twtt+N8avcjHJ0ntezsv2QiEI3OlH8a X1Vi/kGoEi7/F0wNaOuR4hOwmvwMMSeTFdJOlYwHBTZ0urDThlIEiVBApgEt7JvS vKESu33o0YaBYsfzJ9yxaiHxRdAW5MgXTPw70fPZTjNabYn/Z2Hxr3MFt0IFcyuC 7trRL4gF77cgxExzTZjzZ3FGtXeHfkx/pH7LGlLjGYRFNhbOnQeTK4vvAimi5QsA oBo4D9PUrDF0tkhGVkgqGoUimmSDPNZqOp90wVmvitBUPUFOxCgB6o2tibEMxK7M KfYNfEicBO+VqUKaJM9TJgcu7DpA8Ah5EadJF6NG79gmVmeCfl5t3hk2gdWrMQRP buuhCf58ACI4lXSEXwnuQX6Gd4Rk9RijsBtCaaYJ6ZtvoEnp4zinpJAwjQtbGgIM aeC6fPTVkKezSQUID616JauabSxoZgqGsNN6EAUwZcWT4oVJVKEQCBdvcsiCZWID Czufq9O8tpcFy3BVXf4tpHm4LzA9HmR7qPEkWqv19Bopkx2FUBFjNAFRSYnxTU7M sLsMzNWjzvF1uGtU50bvmRLmp60ZA+VrtXFAjc788Ogegf0OexBbtV3RUMldk+VY mnmc7kZj6jF81LMFP8Fr =L/et -----END PGP SIGNATURE----- --TB36FDmn/VVEgNH/-- --===============1986883763== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot --===============1986883763==-- From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Date: Thu, 12 Jul 2012 10:40:51 +0200 Subject: [U-Boot] [PATCH v2 07/19] tegra: fdt: Add LCD definitions for Tegra In-Reply-To: References: <1339604395-6621-1-git-send-email-sjg@chromium.org> <1339604395-6621-8-git-send-email-sjg@chromium.org> <4FDA749D.2030201@wwwdotorg.org> <20120711054842.GB10344@avionic-0098.mockup.avionic-design.de> Message-ID: <20120712084051.GA27022@avionic-0098.adnet.avionic-design.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Thu, Jul 12, 2012 at 10:21:01AM +0200, Simon Glass wrote: > Hi Thierry, > > On Wed, Jul 11, 2012 at 7:48 AM, Thierry Reding > wrote: > > On Wed, Jul 11, 2012 at 06:44:10AM +0200, Simon Glass wrote: > >> Hi Stephen, > >> > >> On Fri, Jun 15, 2012 at 1:32 AM, Stephen Warren wrote: > >> > >> > On 06/13/2012 10:19 AM, Simon Glass wrote: > >> > > Add LCD definitions and also a proposed binding for LCD displays. > >> > > > >> > > The PWFM is in progress on the device-tree-discuss list, so only a > >> > > very basic binding is offered here. > >> > > >> > I believe we have settled on a final representation, it just hasn't been > >> > added into linux-next yet. See: > >> > > >> > > >> > http://gitorious.org/linux-pwm/linux-pwm/commit/d3ce73e5dc86646a6302f2b0f7dd40e8c552fa04 > >> > >> > >> Thanks for the pointer. I suppose this doesn't address clocks as yet, but > >> that's fine. > > > > I was waiting for the common clock framework and DT bindings to get > > ready. This should happen RSN for Tegra so I will probably look at > > adding support for it in. > > OK, are you looking at adding it in U-Boot? No. I don't have much time to spend on U-Boot right now. [...] > I also need a place to put the pwm and GPIOs for the panel itself. > Something like this: > > nvidia,pwm = <&pwm 2 0>; > nvidia,backlight-enable-gpios = <&gpio 28 0>; /* PD4 */ > nvidia,lvds-shutdown-gpios = <&gpio 10 0>; /* PB2 */ > nvidia,backlight-vdd-gpios = <&gpio 176 0>; /* PW0 */ > nvidia,panel-vdd-gpios = <&gpio 22 0>; /* PC6 */ > nvidia,panel-timings = <4 203 17 15>; (number of ms before turning > on the next gpio) > nvidia,bits-per-pixel = <16>; (er, TBD) > > I am thinking of something like a phandle in your rgb node: > > host1x { > dc at 54200000 { > rgb { > nvidia-panel = <&lcd_panel>; > ... > > lcd_panel: panel { > nvidia,pwm = <&pwm 2 0>; > ... > } > > Or have you already solved this problem another way? Linux has a generic PWM backlight driver. This is currently solved by using this in the DT: backlight { compatible = "pwm-backlight"; pwms = <&pwm 0 5000000>; brightness-levels = <0 4 8 16 32 64 128 255>; default-brightness-level = <6>; }; Alex Courbot (Cc'd) has been working on adding a generic way to add GPIO and regulator support to that. I don't know exactly what the lvds-shutdown-gpios and panel-vdd-gpios properties do. If they control hardware connected behind the display controller I suppose they could go into the rgb node. The panel alternative that you propose sounds interesting as well. Maybe the panel should itself contain either a phandle or a subnode for the backlight and collect the properties that you listed above. Thierry -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 836 bytes Desc: not available URL: