Re: [PATCH] ARM: dts: koelsch: Configure pull-up for SOFT_SW GPIO keys

From: "Niklas Söderlund" <niklas.soderlund@ragnatech.se>
To: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Magnus Damm <magnus.damm@gmail.com>,
	Ulrich Hecht <uli+renesas@fpond.eu>,
	Linus Walleij <linus.walleij@linaro.org>,
	linux-renesas-soc@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] ARM: dts: koelsch: Configure pull-up for SOFT_SW GPIO keys
Date: Tue, 23 Mar 2021 00:03:41 +0100	[thread overview]
Message-ID: <YFkiTUJ/xhVN7H+r@oden.dyn.berto.se> (raw)
In-Reply-To: <20210303132941.3938516-1-geert+renesas@glider.be>

Hi Geert,

Thanks for your work.

On 2021-03-03 14:29:41 +0100, Geert Uytterhoeven wrote:
> The GPIO pins connected to the 4 Software Switches ("SOFT_SW", SW2) do
> not have external pull-up resistors, but rely on internal pull-ups being
> enabled.  Fortunately this is satisfied by the initial state of these
> pins.
> 
> Make this explicit by enabling bias-pull-up, to remove the dependency on
> initial state and/or boot loader configuration.
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

> ---
> To be queued in renesas-devel for v5.13.
> 
> It is safe to apply this before R-Car M2-W bias support[1] has landed,
> as pinctrl_bind_pins() does not consider -ENOTSUPP a fatal error.
> 
> [1] https://lore.kernel.org/r/20210303132619.3938128-1-geert+renesas@glider.be
> ---
>  arch/arm/boot/dts/r8a7791-koelsch.dts | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/r8a7791-koelsch.dts b/arch/arm/boot/dts/r8a7791-koelsch.dts
> index 751e07fb102cf454..c6c93c4452ee1e88 100644
> --- a/arch/arm/boot/dts/r8a7791-koelsch.dts
> +++ b/arch/arm/boot/dts/r8a7791-koelsch.dts
> @@ -81,6 +81,9 @@ lbsc {
>  	keyboard {
>  		compatible = "gpio-keys";
>  
> +		pinctrl-0 = <&sw2_pins>;
> +		pinctrl-names = "default";
> +
>  		key-1 {
>  			gpios = <&gpio5 0 GPIO_ACTIVE_LOW>;
>  			linux,code = <KEY_1>;
> @@ -615,6 +618,11 @@ sound_clk_pins: sound_clk {
>  		groups = "audio_clk_a";
>  		function = "audio_clk";
>  	};
> +
> +	sw2_pins: sw2 {
> +		pins = "GP_5_0", "GP_5_1", "GP_5_2", "GP_5_3";
> +		bias-pull-up;
> +	};
>  };
>  
>  &ether {
> -- 
> 2.25.1
> 

-- 
Regards,
Niklas Söderlund