Am 28.10.2014 um 01:00 schrieb Stephen Warren:
On 10/27/2014 05:05 PM, Matthias Klein wrote:
- To be in sync with the GPIO numbers in the datasheet / documentation
I assume that's only relevant because of the second point; the GPIO
IDs in DT files already match the datasheet.
- For userland applications which rely on these GPIO numbers
This isn't a scalable solution for that; this "fix" can only work for
a single GPIO controller in any one system. It'd be better for all
usage to search for the correct GPIO controller in sysfs, find the
base address of that, and then add on the controller-relative GPIO ID.
That way, the same approach is taken irrespective of which GPIO
controller is in use, and there are no special cases.
Perhaps this could be simplified (removing the need to adding
base+offset to get the Linux ID) if the GPIO core exported a
per-controller directory in sysfs for GPIO manipulation (the files in
which used controller-relative numbering), rather than having a single
directory using Linux-internal global GPIO numbering; something like
/sys/class/gpio/gpio@7e200000/export which uses ID 0..N vs.
/sys/class/gpio/export which uses IDs X..X+N where X is arbitary.
Would you accept a patch which implements the "gpio-base" property into
the device tree for pinctrl-bcm2835?
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