Re: [PATCH V1] pinctrl: qcom: spmi-gpio: Add support for qcom,gpios-disallowed property

[Fenglin Wu]

On 8/29/2017 9:51 AM, Shawn Guo wrote:
> On Tue, Aug 29, 2017 at 09:03:02AM +0800, Fenglin Wu wrote:
> > I agree the GPIO's ownership is configurable and it always configured at
> > the very beginning of the device boot up which is not visible by linux
> > kernel drivers/image. Normally, this configuration is fixed in one
> > platform and it's been protected and not allowed to be configured in
> > linux kernel driver. So from linux driver point of view, this is a
> > hardware configuration. I agree the coming patch "spmi: pmic-arb: Move
> > the ownership check to irq_chip callback" would fix the pinctrl-
> > spmi-gpio driver probe failure caused by the ownership mismatch, but
> > this is just hiding the mistake of the kernel configured the GPIOs which
> > not owned by APPS processor.
>
> The kernel does everything just right, using the GPIO that device tree
> tells to use.  If there is something wrong about ownership check, it
> should be fault of that device tree specifies the wrong GPIO, or
> firmware doesn't configure ownership as needed.
> > Shawn

If you thought that the driver registers pins for the GPIOs not owned by
APPS processor is correct, then this patch is no needed.
I agreed with others.
Thanks

Fenglin

> > And these GPIOs will be registered
> > successfully as pinctrl pins and any APPS processor consumer drivers
> > could use this pins. This is not correct even the select_state operation
> > for these pins would failed due to the mode protection in spmi write_cmd
> > calling. I am thinking that not allowing these pins to be register as
> > pinctrl pins should be more straightforward and easy understanding. So I
> > think this patch still have value even the probe failure has been fixed
> > by the coming spmi patch.

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