Re: [PATCH v2] ARM: dts: document pinctrl-single,pins when #pinctrl-cells = 2

From: Tony Lindgren <tony@atomide.com>
To: Drew Fustini <drew@beagleboard.org>
Cc: Rob Herring <robh+dt@kernel.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Jason Kridner <jkridner@beagleboard.org>,
	Robert Nelson <robertcnelson@gmail.com>,
	Trent Piepho <tpiepho@gmail.com>,
	Christina Quast <cquast@hanoverdisplays.com>,
	linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org,
	devicetree@vger.kernel.org, linux-gpio@vger.kernel.org
Subject: Re: [PATCH v2] ARM: dts: document pinctrl-single,pins when #pinctrl-cells = 2
Date: Wed, 23 Sep 2020 10:38:13 +0300	[thread overview]
Message-ID: <20200923073813.GV7101@atomide.com> (raw)
In-Reply-To: <20200919200836.3218536-1-drew@beagleboard.org>

* Drew Fustini <drew@beagleboard.org> [200919 23:10]:
> Document the values in pinctrl-single,pins when #pinctrl-cells = <2>
> 
> Fixes: 27c90e5e48d0 ("ARM: dts: am33xx-l4: change #pinctrl-cells from 1 to 2")
> Reported-by: Trent Piepho <tpiepho@gmail.com>
> Link: https://lore.kernel.org/linux-omap/3139716.CMS8C0sQ7x@zen.local/
> Signed-off-by: Drew Fustini <drew@beagleboard.org>
> ---
> v2 change:
> - rephrase to make it clear that the pin conf value and pin mux value
>   are OR'd together with #pinctrl-cells = <2>

Acked-by: Tony Lindgren <tony@atomide.com>

>  .../bindings/pinctrl/pinctrl-single.txt       | 21 ++++++++++++-------
>  1 file changed, 14 insertions(+), 7 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-single.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-single.txt
> index e705acd3612c..f903eb4471f8 100644
> --- a/Documentation/devicetree/bindings/pinctrl/pinctrl-single.txt
> +++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-single.txt
> @@ -94,16 +94,23 @@ pinctrl-single,bit-per-mux is set), and uses the common pinctrl bindings as
>  specified in the pinctrl-bindings.txt document in this directory.
>  
>  The pin configuration nodes for pinctrl-single are specified as pinctrl
> -register offset and value pairs using pinctrl-single,pins. Only the bits
> -specified in pinctrl-single,function-mask are updated. For example, setting
> -a pin for a device could be done with:
> +register offset and values using pinctrl-single,pins. Only the bits specified
> +in pinctrl-single,function-mask are updated.
> +
> +When #pinctrl-cells = 1, then setting a pin for a device could be done with:
>  
>  	pinctrl-single,pins = <0xdc 0x118>;
>  
> -Where 0xdc is the offset from the pinctrl register base address for the
> -device pinctrl register, and 0x118 contains the desired value of the
> -pinctrl register. See the device example and static board pins example
> -below for more information.
> +Where 0xdc is the offset from the pinctrl register base address for the device
> +pinctrl register, and 0x118 contains the desired value of the pinctrl register.
> +
> +When #pinctrl-cells = 2, then setting a pin for a device could be done with:
> +
> +	pinctrl-single,pins = <0xdc 0x30 0x07>;
> +
> +Where 0x30 is the pin configuration value and 0x07 is the pin mux mode value.
> +These two values are OR'd together to produce the value stored at offset 0xdc.
> +See the device example and static board pins example below for more information.
>  
>  In case when one register changes more than one pin's mux the
>  pinctrl-single,bits need to be used which takes three parameters:
> -- 
> 2.25.1
>