From: Lars-Peter Clausen <lars@metafoo.de>
To: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Thomas Abraham <thomas.abraham@linaro.org>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, kgene.kim@samsung.com,
kwangwoo.lee@gmail.com, patches@linaro.org, jg1.han@samsung.com,
rob.herring@calxeda.com, grant.likely@secretlab.ca, cbou@mail.ru,
kyungmin.park@samsung.com, linux-samsung-soc@vger.kernel.org,
rpurdie@rpsys.net, ben-linux@fluff.org,
broonie@opensource.wolfsonmicro.com, augulis.darius@gmail.com
Subject: Re: [PATCH] backlight: lcd: add driver for raster-type lcd's with gpio controlled panel reset
Date: Sat, 07 Jan 2012 19:32:12 +0100 [thread overview]
Message-ID: <4F088FAC.3000200@metafoo.de> (raw)
In-Reply-To: <20120107182319.GA13181@n2100.arm.linux.org.uk>
On 01/07/2012 07:23 PM, 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 is handled by the LCD framework. Or at least should be, see this patchset
http://www.spinics.net/lists/linux-fbdev/msg04503.html
- Lars
WARNING: multiple messages have this Message-ID (diff)
From: lars@metafoo.de (Lars-Peter Clausen)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] backlight: lcd: add driver for raster-type lcd's with gpio controlled panel reset
Date: Sat, 07 Jan 2012 19:32:12 +0100 [thread overview]
Message-ID: <4F088FAC.3000200@metafoo.de> (raw)
In-Reply-To: <20120107182319.GA13181@n2100.arm.linux.org.uk>
On 01/07/2012 07:23 PM, 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 is handled by the LCD framework. Or at least should be, see this patchset
http://www.spinics.net/lists/linux-fbdev/msg04503.html
- Lars
next prev parent reply other threads:[~2012-01-07 18:33 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-05 15:42 [PATCH] backlight: lcd: add driver for raster-type lcd's with gpio controlled panel reset Thomas Abraham
2012-01-05 15:42 ` Thomas Abraham
2012-01-05 19:07 ` Lars-Peter Clausen
2012-01-05 19:07 ` Lars-Peter Clausen
2012-01-06 6:49 ` Mark Brown
2012-01-06 6:49 ` Mark Brown
2012-01-07 11:04 ` Thomas Abraham
2012-01-07 11:04 ` Thomas Abraham
2012-01-07 17:28 ` Mark Brown
2012-01-07 17:28 ` Mark Brown
2012-01-11 10:51 ` Thomas Abraham
2012-01-11 10:51 ` Thomas Abraham
2012-01-11 17:45 ` Mark Brown
2012-01-11 17:45 ` Mark Brown
2012-01-12 1:34 ` Thomas Abraham
2012-01-12 1:34 ` Thomas Abraham
2012-01-07 10:46 ` Thomas Abraham
2012-01-07 10:46 ` Thomas Abraham
2012-01-07 10:46 ` Thomas Abraham
2012-01-06 2:16 ` Jingoo Han
2012-01-06 2:16 ` Jingoo Han
2012-01-07 10:48 ` Thomas Abraham
2012-01-07 10:48 ` Thomas Abraham
2012-01-06 6:46 ` Olof Johansson
2012-01-06 6:46 ` Olof Johansson
2012-01-06 6:46 ` Olof Johansson
2012-01-07 10:59 ` Thomas Abraham
2012-01-07 10:59 ` Thomas Abraham
2012-01-07 10:59 ` Thomas Abraham
2012-01-07 18:23 ` Russell King - ARM Linux
2012-01-07 18:23 ` Russell King - ARM Linux
2012-01-07 18:32 ` Lars-Peter Clausen [this message]
2012-01-07 18:32 ` Lars-Peter Clausen
2012-01-11 10:58 ` Thomas Abraham
2012-01-11 10:58 ` Thomas Abraham
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