Re: [PATCH 2/5] dt-bindings: pinctrl: brcm,ns-pinmux: extend example

From: Tony Lindgren <tony@atomide.com>
To: "Rafał Miłecki" <zajec5@gmail.com>
Cc: "Linus Walleij" <linus.walleij@linaro.org>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Andy Shevchenko" <andy.shevchenko@gmail.com>,
	linux-gpio@vger.kernel.org, devicetree@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	"Florian Fainelli" <f.fainelli@gmail.com>,
	bcm-kernel-feedback-list@broadcom.com,
	"Rafał Miłecki" <rafal@milecki.pl>
Subject: Re: [PATCH 2/5] dt-bindings: pinctrl: brcm,ns-pinmux: extend example
Date: Tue, 23 Nov 2021 09:38:45 +0200	[thread overview]
Message-ID: <YZyahbYwMFz7baTu@atomide.com> (raw)
In-Reply-To: <20211118132152.15722-3-zajec5@gmail.com>

Hi,

200* Rafał Miłecki <zajec5@gmail.com> [211118 13:30]:
> @@ -83,6 +83,33 @@ examples:
>          reg = <0x1800c1c0 0x24>;
>          reg-names = "cru_gpio_control";
>  
> +        pins {
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +
> +            pin@4 {
> +                reg = <4>;
> +                label = "i2c_scl";
> +            };
> +
> +            pin@5 {
> +                reg = <5>;
> +                label = "i2c_sda";
> +            };
> +        };

The reg property should indicate the hardware offset from the device base
address. The reg values above for 4 and 5 seem to be indexed instead :)
Please update to use real register offsets from the 0x1800c1c0 base
instead. If a reg offset + bit offset are needed, the #address-cells or
#pinctrl-cells can be used.

The main problem using an index is that you need to keep it in sync
between the dts and device driver. And if a new SoC variant adds an entry
between the registers, you end up having to renumber the index.

Regards,

Tony