On 6 May 2015 at 15:06, Johan Hovold wrote:
>
> On Wed, May 06, 2015 at 09:22:22AM +0200, Linus Walleij wrote:
> > On Mon, May 4, 2015 at 10:49 AM, Johan Hovold wrote:
> > > On Mon, Apr 13, 2015 at 01:05:15PM +0200, Martin Fuzzey wrote:
> >
> > >> The above means that, in order to export the GPIO
On Mon, May 4, 2015 at 10:49 AM, Johan Hovold wrote:
> On Mon, Apr 13, 2015 at 01:05:15PM +0200, Martin Fuzzey wrote:
>> The above means that, in order to export the GPIO to userspace via
>> /sys/class/gpio/export the userspace code must know the exact hardware and
>> kernel version information.
On Wed, Apr 15, 2015 at 3:19 PM, Rob Herring wrote:
> On Mon, Apr 13, 2015 at 6:05 AM, Martin Fuzzey wrote:
>> That number, in the case of gpio drviers using dynamic allocation, is not
>> fixed,
>> and may change when:
>> * The kernel version changes and ARCH_NR_GPIOS is changed (happened in 3.
On Mon, Apr 13, 2015 at 6:05 AM, Martin Fuzzey wrote:
> Currently the gpio sysfs interface allows userspace to access simple hardware
> where no kernel driver exists or would be useful.
Whether or not a kernel driver exists can vary by kernel version. The
dtb needs to work either way. The way you
Currently the gpio sysfs interface allows userspace to access simple hardware
where no kernel driver exists or would be useful.
However it requires userspace to know the gpio number that has been assigned
by the kernel.
That number, in the case of gpio drviers using dynamic allocation, is not fix
