Re: [PATCH] arm: dts: sunxi: h3/h5: add gpio-ranges for pio and r_pio

[Andre Przywara <andre.przywara@arm.com>]

On Sun, 22 May 2022 20:20:19 +0300
Andrei Lalaev <andrey.lalaev@gmail.com> wrote:

> Without this property the next node can't be hogged:
> &r_pio {
> 	test_hog {
> 		gpio-hog;
> 		gpios = <0 6 GPIO_ACTIVE_HIGH>;
> 		output-high;
> 	};
> };
> And the appropriate error message:
> "requesting hog GPIO test_hog (chip 1f02c00.pinctrl, offset 6) failed, -517"
> 
> This problem occurs because the "pinctrl-sunxi" calls
> "gpiochip_add_data" that parses "gpio-ranges"
> (using "of_gpiochip_add_pin_range") and registers hogs
> (using "of_gpiochip_scan_gpios").
> So when the gpiolib tries to register hogs it can't find any ranges and
> fails.
> 
> Signed-off-by: Andrei Lalaev <andrey.lalaev@gmail.com>
> ---
>  arch/arm/boot/dts/sunxi-h3-h5.dtsi | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/sunxi-h3-h5.dtsi b/arch/arm/boot/dts/sunxi-h3-h5.dtsi
> index d7e9f977f986..4193bf962b7d 100644
> --- a/arch/arm/boot/dts/sunxi-h3-h5.dtsi
> +++ b/arch/arm/boot/dts/sunxi-h3-h5.dtsi
> @@ -404,6 +404,9 @@ pio: pinctrl@1c20800 {
>  			#gpio-cells = <3>;
>  			interrupt-controller;
>  			#interrupt-cells = <3>;
> +			gpio-ranges = <&pio 0 0 22>, <&pio 64 64 17>,
> +				      <&pio 96 96 18>, <&pio 128 128 16>,
> +				      <&pio 160 160 7>, <&pio 192 192 14>;

But this is somewhat redundant information, because the pinctrl driver
knows about those values, as they are derived from the big struct
sunxi_desc_pin definition.
So wouldn't it be smarter to put a call to
gpiochip_add_pingroup_range() somewhere into the sunxi pinctrl driver,
so that it would automatically work for all SoCs?

Cheers,
Andre

>  
>  			csi_pins: csi-pins {
>  				pins = "PE0", "PE2", "PE3", "PE4", "PE5",
> @@ -937,6 +940,7 @@ r_pio: pinctrl@1f02c00 {
>  			#gpio-cells = <3>;
>  			interrupt-controller;
>  			#interrupt-cells = <3>;
> +			gpio-ranges = <&r_pio 0 352 12>;
>  
>  			r_ir_rx_pin: r-ir-rx-pin {
>  				pins = "PL11";