From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH v3 1/2] video: ARM CLCD: Add DT support Date: Mon, 23 Sep 2013 10:03:18 -0600 Message-ID: <52406646.709@wwwdotorg.org> References: <1379351934-25415-1-git-send-email-pawel.moll@arm.com> <52376180.1090001@wwwdotorg.org> <1379435799.9205.16.camel@hornet> <5238CBE9.2060800@wwwdotorg.org> <1379522363.9244.12.camel@hornet> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1379522363.9244.12.camel@hornet> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Pawel Moll Cc: "linux-fbdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org" , Mark Rutland , Ian Campbell , Jean-Christophe Plagniol-Villard , Tomi Valkeinen , Russell King , Arnd Bergmann , Sylwester Nawrocki List-Id: devicetree@vger.kernel.org On 09/18/2013 10:39 AM, Pawel Moll wrote: > On Tue, 2013-09-17 at 22:34 +0100, Stephen Warren wrote: >>> On Tue, 2013-09-17 at 17:36 +0100, Pawel Moll wrote: >>>> On Mon, 2013-09-16 at 20:52 +0100, Stephen Warren wrote: >>>>>> +- arm,pl11x,panel-data-pads: array of 24 cells, each of them describing >>>>>> + a function of one of the CLD pads, >>>>>> + starting from 0 up to 23; each pad can >>>>>> + be described by one of the following values: >>>>>> + - 0: reserved (not connected) >>>>>> + - 0x100-0x107: color upper STN panel data 0 to 7 >>>>> ... >>>>> >>>>> I assume those are the raw values that go into the HW? >>> >>> No, they can be considered "labels", defining the way pads are used >>> (wired). Then, basing on this information, the driver is configuring the >>> cell, eg. selecting STN or TFT mode (thus switching the output between >>> panel formatter and raw RGB data source). >> >> Oh, why not just use the raw values from the HW registers for this? > > How do you mean? Based on the the way the "LCD data" lines are wired up, > the driver has to decide whether to select STN (LCDControl &= ~(1<<5)) > or TFT mode (LCDControl |= 1<<5), then figures out what memory pixel > formats are possible (based on this will set LCDControl[3..1] in > runtime, depending on the mode selected by the user). There isn't a > separate register as such configuring output pads. It's just the way > they can used depends on the way they're wired up. It sounds like you could just put LCDControl & 0x2e in the DT rather than using values such as 0x100..0x107, which don't appear to match the register format you mentioned above. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html