From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Subject: Re: [PATCH 0/3] OMAP: Introduce Backlight driver for Sharp LS037V7DW01 LCD panel Date: Wed, 01 Dec 2010 17:32:55 +0200 Message-ID: <1291217575.10133.165.camel@tubuntu> References: <1291118860-10325-1-git-send-email-bryan.wu@canonical.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.nokia.com ([147.243.128.26]:50448 "EHLO mgw-da02.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750857Ab0LAPdM (ORCPT ); Wed, 1 Dec 2010 10:33:12 -0500 In-Reply-To: <1291118860-10325-1-git-send-email-bryan.wu@canonical.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: ext Bryan Wu Cc: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, gadiyar@ti.com, rpurdie@rpsys.net Hi, On Tue, 2010-11-30 at 20:07 +0800, ext Bryan Wu wrote: > After instroducing generic DPI panel driver for OMAP DSS2 system, we need to > split out backlight driver from Sharp LS037V7DW01 panel driver before we move > to the generic DPI panel driver. > > This patchset introcuded backlight driver and cleanup the old Sharp LS037V7DW01 > panel driver related code. > > It's built on mainline 2.6.37-rc4 > > Bryan Wu (3): > Backlight: driver for Sharp LS037V7DW01 panel on OMAP machine > OMAP: move Sharp LS LCD panel device to generic DPI panel driver and new backlight driver > OMAP: DSS2: remove Sharp LS037V7DW01 panel driver I don't think this is quite the right direction. All the backlight driver does is call a function in the board file. It's not really a "sharp ls backlight driver", but rather generic one. I'm not even sure if it needs the dssdev pointer. This kind of backlight is, in a sense, totally separate component from the panel itself. All they have in common is that they are packaged in the same physical display module, and they usually share the same connector. I have seen three kinds of backlights on OMAP devices: - on/off GPIO (like on 3430 SDP) - PWM based (zoom seems to have this) - Panel controlled (Taal-panel. Also PWM based, but OMAP doesn't see that) The first two could (should?) be totally separate backlights from the panel itself. For those, a generic backlight driver could perhaps work. The third one needs to be quite tied to the panel driver, and I'm not sure how easy it would be to have a separate driver for that. Tomi