From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Date: Tue, 30 Apr 2013 15:07:57 +0000 Subject: Re: Re[2]: [PATCH V2] video: implement a simple framebuffer driver Message-Id: <201304301707.57197.arnd@arndb.de> List-Id: References: <1365043183-28905-1-git-send-email-swarren@wwwdotorg.org> <517F753F.5090909@ti.com> <1367332685.945287573@f287.mail.ru> In-Reply-To: <1367332685.945287573@f287.mail.ru> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org On Tuesday 30 April 2013, Alexander Shiyan wrote: > > On 04/04/2013 05:39 AM, Stephen Warren wrote: > > > A simple frame-buffer describes a raw memory region that may be rendered > > > to, with the assumption that the display hardware has already been set > > > up to scan out from that buffer. > > > > > > This is useful in cases where a bootloader exists and has set up the > > > display hardware, but a Linux driver doesn't yet exist for the display > > > hardware. > > > > > > Signed-off-by: Stephen Warren > ... > > > + framebuffer { > > > + compatible = "simple-framebuffer"; > > > + reg = <0x1d385000 (1600 * 1200 * 2)>; > > > + width = <1600>; > > > + height = <1200>; > > > + stride = <(1600 * 2)>; > > > + format = "r5g6b5"; > > > + }; > > > > I'm not an expert on DT, but I think the point of DT is to describe the > > hardware. This doesn't describe the hardware at all. > > On my incompetent opinion, "bpp" parameter can replace size of > framebuffer and "stride". Is not it? Not necessarily: you could have a stride that is larger than a line. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Tue, 30 Apr 2013 17:07:57 +0200 Subject: [PATCH V2] video: implement a simple framebuffer driver In-Reply-To: <1367332685.945287573@f287.mail.ru> References: <1365043183-28905-1-git-send-email-swarren@wwwdotorg.org> <517F753F.5090909@ti.com> <1367332685.945287573@f287.mail.ru> Message-ID: <201304301707.57197.arnd@arndb.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tuesday 30 April 2013, Alexander Shiyan wrote: > > On 04/04/2013 05:39 AM, Stephen Warren wrote: > > > A simple frame-buffer describes a raw memory region that may be rendered > > > to, with the assumption that the display hardware has already been set > > > up to scan out from that buffer. > > > > > > This is useful in cases where a bootloader exists and has set up the > > > display hardware, but a Linux driver doesn't yet exist for the display > > > hardware. > > > > > > Signed-off-by: Stephen Warren > ... > > > + framebuffer { > > > + compatible = "simple-framebuffer"; > > > + reg = <0x1d385000 (1600 * 1200 * 2)>; > > > + width = <1600>; > > > + height = <1200>; > > > + stride = <(1600 * 2)>; > > > + format = "r5g6b5"; > > > + }; > > > > I'm not an expert on DT, but I think the point of DT is to describe the > > hardware. This doesn't describe the hardware at all. > > On my incompetent opinion, "bpp" parameter can replace size of > framebuffer and "stride". Is not it? Not necessarily: you could have a stride that is larger than a line. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: Re[2]: [PATCH V2] video: implement a simple framebuffer driver Date: Tue, 30 Apr 2013 17:07:57 +0200 Message-ID: <201304301707.57197.arnd@arndb.de> References: <1365043183-28905-1-git-send-email-swarren@wwwdotorg.org> <517F753F.5090909@ti.com> <1367332685.945287573@f287.mail.ru> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1367332685.945287573@f287.mail.ru> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Alexander Shiyan Cc: linux-fbdev@vger.kernel.org, Stephen Warren , devicetree-discuss@lists.ozlabs.org, Rob Clark , Tomi Valkeinen , linux-rpi-kernel@lists.infradead.org, Olof Johansson , Andrew Morton , linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org On Tuesday 30 April 2013, Alexander Shiyan wrote: > > On 04/04/2013 05:39 AM, Stephen Warren wrote: > > > A simple frame-buffer describes a raw memory region that may be rendered > > > to, with the assumption that the display hardware has already been set > > > up to scan out from that buffer. > > > > > > This is useful in cases where a bootloader exists and has set up the > > > display hardware, but a Linux driver doesn't yet exist for the display > > > hardware. > > > > > > Signed-off-by: Stephen Warren > ... > > > + framebuffer { > > > + compatible = "simple-framebuffer"; > > > + reg = <0x1d385000 (1600 * 1200 * 2)>; > > > + width = <1600>; > > > + height = <1200>; > > > + stride = <(1600 * 2)>; > > > + format = "r5g6b5"; > > > + }; > > > > I'm not an expert on DT, but I think the point of DT is to describe the > > hardware. This doesn't describe the hardware at all. > > On my incompetent opinion, "bpp" parameter can replace size of > framebuffer and "stride". Is not it? Not necessarily: you could have a stride that is larger than a line. Arnd