[U-Boot] What can cause gpio_request return negative value

Nemanja Savic vlasinac at gmail.com
Thu Aug 15 14:05:05 UTC 2019

It return -2 which should be -ENOENT. In the comment at the end of
gpio_to_device() it is written "No such GPIO".
Are there any prerequisites before calling gpio_request regarding device
tree or something else?

On Thu, Aug 15, 2019 at 3:09 PM Adam Ford <aford173 at gmail.com> wrote:

> On Thu, Aug 15, 2019 at 7:46 AM Nemanja Savic <vlasinac at gmail.com> wrote:
> >
> > Hi all,
> >
> > I am struggling with porting our old board init code for a sabre auto
> based
> > custom board with i.MX6 DualLite processor. The code used to work in our
> > older u-boot version, but what I saw in mx6qsabreauto.c is that the new
> > style is by using new driver model which means the gpio should be first
> > requested. However gpio_request returns negative value in my case. Where
> > could the problem be? As far as I could see our device tree doesn't
> reserve
> > this pin for other purpose. It is even not mentioned there. The only
> thing
> > related to those pins are iomux pin definitions in the device tree but
> > removing that doesn't help at all. Also device tree for the Sabre Auto
> > board doesn't mention gpio pins that they use in their u-boot. I am
> dealing
> > with 2017.03 version of u-boot.
> Do you know what the negative value is?  include/linux/errno.h  should
> have a list of error numbers which should correlate to the error
> you're seeing.  That should also tell you what the error means.  From
> there, you should be able to search the code for where that error
> might return.
> adam
> > _______________________________________________
> > U-Boot mailing list
> > U-Boot at lists.denx.de
> > https://lists.denx.de/listinfo/u-boot

Nemanja Savić

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