On Thu, Jun 22, 2017 at 10:54 PM, Timur Tabi [off-list ref] wrote:

On Qualcomm Technologies QDF2xxx platforms, only a subset of the GPIOs
are actually available to the HLOS.  The others are blocked by the XPU,
and any attempt to access them will cause an XPU violation that halts
the system.

That's a bummer. Looking for Bj?rn's review on this patch.

Instead, the ACPI table now lists only specific GPIOs that are exposed
externally as generic GPIO pins.

The ACPI table or the device tree property "gpios" right?

(But maybe this system is only using ACPI.)

To maintain consistency, the GPIOs are
enumerated 0 .. (N-1) as before, so that "gpio0" is really whatever is
the first GPIO listed in ACPI.  The actual mapping is available via
/sys/kernel/debug/gpio.

I think using "lsgpio" fron tools/gpio/lsgpio.c is better to inspect
the available GPIOs.

If you haven't tested the GPIO tools, please try it out.

Yours,
Linus Walleij