From mboxrd@z Thu Jan 1 00:00:00 1970 From: urx.forever@gmail.com (Yuri Ludkevich) Date: Wed, 11 Aug 2010 11:10:11 -0000 Subject: colibri PXA320 and UCB1400 - touch screen troubles In-Reply-To: <201008111255.24657.marek.vasut@gmail.com> References: <20100811105125.GI10432@buzzloop.caiaq.de> <201008111255.24657.marek.vasut@gmail.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 2010/8/11 Marek Vasut > Dne St 11. srpna 2010 12:51:25 Daniel Mack napsal(a): > > 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? > > nCS3 is the chipselect for CPLD space actually (and the EXT chipselects). > If > it's configured as nCS3, you can write to the CPLD, but in case you don't > need > PCMCIA (and ext. chipselects), you should be ok either way. > > And as Dan said, don't mix GPIO4 and GPIO4_2 :) > > Yep. I know about CPLD. Our board do not use PCMCIA, only SD/MMC. So for us it should work. But if someone wants to use both PCMCIA and touchscreen - how to configure this GPIOs properly? -------------- next part -------------- An HTML attachment was scrubbed... URL: