[PATCH] gpio: uclass: Introduce gpio-hog-optional property

[Fabio Estevam]

Hi Nate and Simon,

On Mon, Sep 12, 2022 at 2:55 PM Nate Drude <nate.d at variscite.com> wrote:
>
> gpio_hog_probe_all is invoked by init_sequence_r in board_r.c.
> If device_probe fails for any gpio-hog, boot hangs with the following error:
>
> > initcall sequence 00000000fffc8e18 failed at call 000000004023b320 (err=-121)
> > ### ERROR ### Please RESET the board ###
>
> gpio-hog-optional allows the boot sequence to continue if device_probe
> fails for optional gpio-hog(s).
>
> Signed-off-by: Nate Drude <nate.d at variscite.com>
> ---
>  doc/device-tree-bindings/gpio/gpio.txt | 1 +
>  drivers/gpio/gpio-uclass.c             | 4 +++-
>  2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/doc/device-tree-bindings/gpio/gpio.txt b/doc/device-tree-bindings/gpio/gpio.txt
> index 1481ed607d..02d296316b 100644
> --- a/doc/device-tree-bindings/gpio/gpio.txt
> +++ b/doc/device-tree-bindings/gpio/gpio.txt
> @@ -189,6 +189,7 @@ gpio-controller's driver probe function.
>  Each GPIO hog definition is represented as a child node of the GPIO controller.
>  Required properties:
>  - gpio-hog:   A property specifying that this child node represents a GPIO hog.
> +- gpio-hog-optional: A property specifying to continue boot when device_probe fails in gpio_hog_probe_all

gpio-hog-optional property does not exist in Linux.

If this property is introduced then U-Boot and Linux devicetrees will
not be in sync.

Can this be fixed differently?