colibri PXA320 and UCB1400 - touch screen troubles

Yuri Ludkevich urx.forever at gmail.com
Wed Aug 11 06:08:14 EDT 2010


2010/8/11 Daniel Mack <daniel at caiaq.de>

> You dropped all recipients again and only replied to me.
> PLEASE DON'T DO THAT.
> Always keep all people in the loop, always.
>
> On Wed, Aug 11, 2010 at 01:50:43PM +0400, Yuri Ludkevich wrote:
> > 2010/8/11 Daniel Mack <daniel at caiaq.de>
> > > According to my reverse engineering, this should be GPIO4_2.
> > >
> >
> > Thanks a lot.
> >
> > BTW: does /sys/class/gpio/export support GPIOX_2 pins?
>
> 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.
>
>
> HTH,
> Daniel
>
> Sorry about other recipients.

Hmmm. I found with pxaregs tool what both GPIO4 and GPIO4_2 configured as
GPIO. May be this cause irq autodetection to fail?
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