Re: [PATCH 2/4] gpio: sifive: Add DT documentation for SiFive GPIO

From: Rob Herring <robh@kernel.org>
To: Yash Shah <yash.shah@sifive.com>
Cc: "linus.walleij@linaro.org" <linus.walleij@linaro.org>,
	"bgolaszewski@baylibre.com" <bgolaszewski@baylibre.com>,
	"mark.rutland@arm.com" <mark.rutland@arm.com>,
	"palmer@dabbelt.com" <palmer@dabbelt.com>,
	"Paul Walmsley ( Sifive)" <paul.walmsley@sifive.com>,
	"aou@eecs.berkeley.edu" <aou@eecs.berkeley.edu>,
	"tglx@linutronix.de" <tglx@linutronix.de>,
	"jason@lakedaemon.net" <jason@lakedaemon.net>,
	"maz@kernel.org" <maz@kernel.org>,
	"bmeng.cn@gmail.com" <bmeng.cn@gmail.com>,
	"atish.patra@wdc.com" <atish.patra@wdc.com>,
	Sagar Kadam <sagar.kadam@sifive.com>,
	"linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-riscv@lists.infradead.org"
	<linux-riscv@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Sachin Ghadi <sachin.ghadi@sifive.com>
Subject: Re: [PATCH 2/4] gpio: sifive: Add DT documentation for SiFive GPIO
Date: Mon, 18 Nov 2019 10:53:45 -0600	[thread overview]
Message-ID: <20191118165345.GA3935@bogus> (raw)
In-Reply-To: <1573560684-48104-3-git-send-email-yash.shah@sifive.com>

On Tue, Nov 12, 2019 at 12:12:06PM +0000, Yash Shah wrote:
> DT documentation for GPIO controller added.
> 
> Signed-off-by: Wesley W. Terpstra <wesley@sifive.com>
> [Atish: Compatible string update]
> Signed-off-by: Atish Patra <atish.patra@wdc.com>
> Signed-off-by: Yash Shah <yash.shah@sifive.com>
> ---
>  .../devicetree/bindings/gpio/gpio-sifive.txt       | 33 ++++++++++++++++++++++
>  1 file changed, 33 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/gpio/gpio-sifive.txt

Please make this a schema. See 
Documentation/devicetree/writing-schema.rst.

> 
> diff --git a/Documentation/devicetree/bindings/gpio/gpio-sifive.txt b/Documentation/devicetree/bindings/gpio/gpio-sifive.txt
> new file mode 100644
> index 0000000..d3416d5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/gpio-sifive.txt
> @@ -0,0 +1,33 @@
> +SiFive GPIO controller bindings
> +
> +Required properties:
> +- compatible: Should be "sifive,<chip>-gpio" and "sifive,gpio<version>".
> +  Supported compatible strings are: "sifive,fu540-c000-gpio" for the SiFive
> +  GPIO v0 as integrated onto the SiFive FU540 chip, and "sifive,gpio0" for the
> +  SiFive GPIO v0 IP block with no chip integration tweaks.
> +  Please refer to sifive-blocks-ip-versioning.txt for details.
> +- reg: Physical base address and length of the controller's registers.
> +- clocks: Should contain a clock identifier for the GPIO's parent clock.
> +- #gpio-cells : Should be 2
> +  - The first cell is the GPIO offset number.
> +  - The second cell indicates the polarity of the GPIO
> +- gpio-controller : Marks the device node as a GPIO controller.
> +- interrupt-controller: Marks the device node as an interrupt controller.
> +- #interrupt-cells : Should be 2.
> +  - The first cell is the GPIO offset number within the GPIO controller.
> +  - The second cell is the edge/level to use for interrupt generation.
> +- interrupts: Specify the interrupts, one per GPIO

How many GPIOs?

> +
> +Example:
> +
> +gpio: gpio@10060000 {
> +	compatible = "sifive,fu540-c000-gpio","sifive,gpio0";

space                                         ^

> +	interrupt-parent = <&plic>;
> +	interrupts = <7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22>;
> +	reg = <0x0 0x10060000 0x0 0x1000>;
> +	clocks = <&tlclk>;
> +	gpio-controller;
> +	#gpio-cells = <2>;
> +	interrupt-controller;
> +	#interrupt-cells = <2>;
> +};
> -- 
> 2.7.4
> 