From mboxrd@z Thu Jan 1 00:00:00 1970 From: daniel@caiaq.de (Daniel Mack) Date: Wed, 11 Aug 2010 12:51:25 +0200 Subject: colibri PXA320 and UCB1400 - touch screen troubles In-Reply-To: References: <201008111042.52631.marek.vasut@gmail.com> <201008111107.29839.marek.vasut@gmail.com> <20100811094543.GO17833@buzzloop.caiaq.de> <20100811100210.GP17833@buzzloop.caiaq.de> <20100811101239.GR17833@buzzloop.caiaq.de> Message-ID: <20100811105125.GI10432@buzzloop.caiaq.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Aug 11, 2010 at 02:46:15PM +0400, Yuri Ludkevich wrote: > 2010/8/11 Daniel Mack > > On Wed, Aug 11, 2010 at 02:08:10PM +0400, Yuri Ludkevich wrote: > > > 2010/8/11 Daniel Mack > > > > Yes, they are aliases to the signals without the "_2" suffix. Quoting > > > > the PXA reference manual, chapter 5.3: > > > > > > > > GPIO<6_0>_2: > > > > > > > > General-Purpose IO Ports, second instantiation. The same signals as > > > > GPIO<6:0>, but they are given separate names because they are > > configured > > > > on separate multi-function pins. The recommended configuration is for > > > > both multi-function pin instantiations of these GPIOs not to be > > > > configured simultaneously for GPIO functionality. The preferred > > > > configuration for dual instantiation GPIO usage (that is, using both > > > > GPIO<6:0> and GPIO<6:0>_2 functions) is to configure one multi-function > > > > pin as a GPIO and the second multi-function pin instantiation for an > > > > alternate function other than a GPIO function. Configuring GPIO<6:0> to > > > > be present on two separate multi-function pins is not recommended. > > > > However, when GPIO<6:0> is configured as an output and both > > > > multi-function pin instantiations are programmed for GPIO function, the > > > > primary and secondary instantiation of the multi-function pins are both > > > > outputs from the common GGPIO<6:0> signal. However, when GPIO<6:0> is > > an > > > > input, the inputs from both multi-function pin instantiations are ORed > > > > together before the result is sent to the internal GPIO<6:0> input > > > > logic. > > > > > > Hmmm. I found with pxaregs tool what both GPIO4 and GPIO4_2 configured as > > > GPIO. May be this cause irq autodetection to fail? > > > > No - if you don't tell the driver which GPIO the interrupt line is > > connected to, it can't know. But as the reference manual says, such > > configurations should be avoided. > > > > You're welcome to come up with a patch :) > > > > Daniel > > > I configure GPIO4 pin as nCS3 (alternate function #1) in colibri-pxa320.c > and after that irq autoprobing found valid irq for UCB1400. So touchscreen > now working just fine. Good. Can you share a patch? > May be I need to check other second instantiation pins for same thing? Sure, double-checking can't harm. If you find anything, feel free to fix it up. Just make sure you read Documentation/SubmittingPatches in order to avoid the most common pitfalls :) Thanks, Daniel