From mboxrd@z Thu Jan 1 00:00:00 1970 From: thomas.abraham@linaro.org (Thomas Abraham) Date: Wed, 11 Jan 2012 16:28:53 +0530 Subject: [PATCH] backlight: lcd: add driver for raster-type lcd's with gpio controlled panel reset In-Reply-To: <20120107182319.GA13181@n2100.arm.linux.org.uk> References: <1325778146-27056-1-git-send-email-thomas.abraham@linaro.org> <20120107182319.GA13181@n2100.arm.linux.org.uk> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Russell, On 7 January 2012 23:53, Russell King - ARM Linux wrote: > On Thu, Jan 05, 2012 at 09:12:26PM +0530, Thomas Abraham wrote: >> Add a lcd panel driver for simple raster-type lcd's which uses a gpio >> controlled panel reset. The driver controls the nRESET line of the panel >> using a gpio connected from the host system. The Vcc supply to the panel >> is (optionally) controlled using a voltage regulator. This driver excludes >> support for lcd panels that use a serial command interface or direct >> memory mapped IO interface. > > I'm trying to work out what kind of LCD panel this is for. ?I assume > not the panels which would be connected to a SoC, which have a parallel > interface to a frame buffer device (LCD controller)? > > If this is for these kinds of LCD panels, how are you handling the > timing required for active panels - some of which must not be powered > up without the LCD controller first being setup and enabled, and must > be powered down before the LCD controller is disabled. > > I've seen this requirement with panels connected to ARM Ltd's development > boards, and also some SoCs. This patch is for passive panels that use a nRESET line controlled by a SoC GPIO and the panel do not use serial command interface (i2c or spi) or memory-mapped-io for panel control. Panels that just need a nRESET to be controlled can be handled by this driver. Thanks, Thomas.