Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757485AbaFSHy2 (ORCPT ); Thu, 19 Jun 2014 03:54:28 -0400 Received: from top.free-electrons.com ([176.31.233.9]:57848 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750887AbaFSHyZ (ORCPT ); Thu, 19 Jun 2014 03:54:25 -0400 Message-ID: <53A2972E.60202@free-electrons.com> Date: Thu, 19 Jun 2014 09:54:22 +0200 From: Boris BREZILLON User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Bo Shen CC: Thierry Reding , Nicolas Ferre , David Airlie , Samuel Ortiz , Lee Jones , devicetree@vger.kernel.org, Jean-Jacques Hiblot , linux-doc@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-pwm@vger.kernel.org, Alexandre Belloni , Laurent Pinchart , Jean-Christophe Plagniol-Villard , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 7/7] ARM: at91/dt: enable the LCD panel on sama5d3xek boards References: <1402329860-27520-1-git-send-email-boris.brezillon@free-electrons.com> <1402329860-27520-8-git-send-email-boris.brezillon@free-electrons.com> <53A28D49.2040400@atmel.com> In-Reply-To: <53A28D49.2040400@atmel.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19/06/2014 09:12, Bo Shen wrote: > Hi Boris, > > On 06/10/2014 12:04 AM, Boris BREZILLON wrote: >> diff --git a/arch/arm/boot/dts/sama5d33ek.dts >> b/arch/arm/boot/dts/sama5d33ek.dts >> index cbd6a3f..f2ab41d 100644 >> --- a/arch/arm/boot/dts/sama5d33ek.dts >> +++ b/arch/arm/boot/dts/sama5d33ek.dts >> @@ -36,9 +36,33 @@ >> macb0: ethernet@f0028000 { >> status = "okay"; >> }; >> + >> + hlcdc: hlcdc@f0030000 { >> + status = "okay"; >> + >> + hlcdc-display-controller { >> + atmel,panel = <&panel 3 0>; > > One question here, in the driver code, it will configuration the frame > buffer mode depends on this parameter. > So, my question is if the framebuffer bits per pixel is different with > output bits per pixel, how to setting it? > > For example, frame buffer use 16 bits/pixel, while output 24 bits/pixel. Actually the HLCDC is responsible for converting input format (either RGB or YUV) to output format (one of the four supported RGB formats). AFAICT, the HLCDC always converts the input format in RGB888 and then only use the relevant bits (i.e. if the output is RGB565, it will only takes MSB for each color). The REP field (available in all layer, e.g. LCDC_BASECFG4 for the base layer) is here to tell how the HLCDC should expand to 24 bits format. All this means that we don't have to bother about input to output format conversion. > >> + }; >> + }; >> }; >> }; >> > > Best Regards, > Bo Shen -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/