Re: [PATCH v4 4/8] dt-bindings: Add doc for the Ingenic TCU drivers

[Marc Zyngier <marc.zyngier@arm.com>]

On 17/03/18 23:28, Paul Cercueil wrote:
> Add documentation about how to properly use the Ingenic TCU
> (Timer/Counter Unit) drivers from devicetree.
> 
> Signed-off-by: Paul Cercueil <paul@crapouillou.net>
> ---
>  .../bindings/clock/ingenic,tcu-clocks.txt          | 42 ++++++++++++++++
>  .../bindings/interrupt-controller/ingenic,tcu.txt  | 39 +++++++++++++++
>  .../devicetree/bindings/mfd/ingenic,tcu.txt        | 56 ++++++++++++++++++++++
>  .../devicetree/bindings/timer/ingenic,tcu.txt      | 41 ++++++++++++++++
>  4 files changed, 178 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/clock/ingenic,tcu-clocks.txt
>  create mode 100644 Documentation/devicetree/bindings/interrupt-controller/ingenic,tcu.txt
>  create mode 100644 Documentation/devicetree/bindings/mfd/ingenic,tcu.txt
>  create mode 100644 Documentation/devicetree/bindings/timer/ingenic,tcu.txt
> 
>  v4: New patch in this series. Corresponds to V2 patches 3-4-5 with
>  added content.
> 
> diff --git a/Documentation/devicetree/bindings/clock/ingenic,tcu-clocks.txt b/Documentation/devicetree/bindings/clock/ingenic,tcu-clocks.txt
> new file mode 100644
> index 000000000000..471d27078599
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/ingenic,tcu-clocks.txt
> @@ -0,0 +1,42 @@
> +Ingenic SoC TCU binding
> +
> +The TCU is the Timer/Counter Unit present in all Ingenic SoCs. It features 8
> +channels, each one having its own clock, that can be started and stopped,
> +reparented, and reclocked.
> +
> +Required properties:
> +- compatible : One of:
> +  * ingenic,jz4740-tcu-clocks,
> +  * ingenic,jz4770-tcu-clocks,
> +  * ingenic,jz4780-tcu-clocks.
> +- clocks : List of phandle & clock specifiers for clocks external to the TCU.
> +  The "pclk", "rtc" and "ext" clocks should be provided.
> +- clock-names : List of name strings for the external clocks.
> +- #clock-cells: Should be 1.
> +  Clock consumers specify this argument to identify a clock. The valid values
> +  may be found in <dt-bindings/clock/ingenic,tcu.h>.
> +
> +Example:
> +
> +/ {
> +	tcu: mfd@10002000 {
> +		compatible = "ingenic,tcu", "simple-mfd", "syscon";
> +		reg = <0x10002000 0x1000>;
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +		ranges = <0x0 0x10002000 0x1000>;
> +
> +		tcu_clk: clocks@10 {
> +			compatible = "ingenic,jz4740-tcu-clocks";
> +			reg = <0x10 0xff0>;
> +
> +			clocks = <&ext>, <&rtc>, <&pclk>;
> +			clock-names = "ext", "rtc", "pclk";
> +
> +			#clock-cells = <1>;
> +		};
> +	};
> +};
> +
> +For information about the top-level "ingenic,tcu" compatible node and other
> +children nodes, see Documentation/devicetree/bindings/mfd/ingenic,tcu.txt.
> diff --git a/Documentation/devicetree/bindings/interrupt-controller/ingenic,tcu.txt b/Documentation/devicetree/bindings/interrupt-controller/ingenic,tcu.txt
> new file mode 100644
> index 000000000000..7f3af2da77cd
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interrupt-controller/ingenic,tcu.txt
> @@ -0,0 +1,39 @@
> +Ingenic SoCs Timer/Counter Unit Interrupt Controller
> +
> +Required properties:
> +
> +- compatible : should be "ingenic,<socname>-tcu-intc". Valid strings are:
> +  * ingenic,jz4740-tcu-intc
> +  * ingenic,jz4770-tcu-intc
> +  * ingenic,jz4780-tcu-intc
> +- interrupt-controller : Identifies the node as an interrupt controller
> +- #interrupt-cells : Specifies the number of cells needed to encode an
> +  interrupt source. The value shall be 1.
> +- interrupt-parent : phandle of the interrupt controller.
> +- interrupts : Specifies the interrupt the controller is connected to.
> +
> +Example:
> +
> +/ {
> +	tcu: mfd@10002000 {
> +		compatible = "ingenic,tcu", "simple-mfd", "syscon";
> +		reg = <0x10002000 0x1000>;
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +		ranges = <0x0 0x10002000 0x1000>;
> +
> +		tcu_irq: interrupt-controller@20 {
> +			compatible = "ingenic,jz4740-tcu-intc";
> +			reg = <0x20 0x20>;
> +
> +			interrupt-controller;
> +			#interrupt-cells = <1>;
> +
> +			interrupt-parent = <&intc>;
> +			interrupts = <15>;
> +		};
> +	};
> +};
> +
> +For information about the top-level "ingenic,tcu" compatible node and other
> +children nodes, see Documentation/devicetree/bindings/mfd/ingenic,tcu.txt.
> diff --git a/Documentation/devicetree/bindings/mfd/ingenic,tcu.txt b/Documentation/devicetree/bindings/mfd/ingenic,tcu.txt
> new file mode 100644
> index 000000000000..5742c3f21550
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/ingenic,tcu.txt
> @@ -0,0 +1,56 @@
> +Ingenic JZ47xx SoCs Timer/Counter Unit devicetree bindings
> +----------------------------------------------------------
> +
> +For a description of the TCU hardware and drivers, have a look at
> +Documentation/mips/ingenic-tcu.txt.
> +
> +The TCU is implemented as a parent node, whose role is to create the
> +regmap, and child nodes for the various drivers listed in the aforementioned
> +document.

You're describing the Linux driver here. Please stick to a description
of the HW.

> +
> +Required properties:
> +
> +- compatible: must be "ingenic,tcu", "simple-mfd", "syscon";

Without any provision for an SoC version? Seems bold...

> +- reg: Should be the offset/length value corresponding to the TCU registers
> +- #address-cells: Should be <1>;
> +- #size-cells: Should be <1>;
> +- ranges: Should be one range for the full TCU registers area
> +
> +Accepted children nodes:
> +- Documentation/devicetree/bindings/interrupt-controller/ingenic,tcu.txt
> +- Documentation/devicetree/bindings/clock/ingenic,tcu-clocks.txt
> +- Documentation/devicetree/bindings/timer/ingenic,tcu.txt

It is slightly confusing that you have 3 files named ingenic,tcu.txt.
How about ingenic,tcu-intc.txt and ingenic,tcu-timer.txt (amending the
binding for the timer)?

> +
> +
> +Example:
> +
> +/ {
> +	tcu: mfd@10002000 {
> +		compatible = "ingenic,tcu", "simple-mfd", "syscon";
> +		reg = <0x10002000 0x1000>;
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +		ranges = <0x0 0x10002000 0x1000>;
> +
> +		tcu_irq: interrupt-controller@20 {
> +			compatible = "ingenic,jz4740-tcu-intc";
> +			reg = <0x20 0x20>;
> +			...
> +		};
> +
> +		tcu_clk: clocks@10 {
> +			compatible = "ingenic,jz4740-tcu-clocks";
> +			reg = <0x10 0xff0>;
> +			...
> +		};
> +
> +		tcu_timer: timer@10 {
> +			compatible = "ingenic,jz4740-tcu";
> +			reg = <0x10 0xff0>;
> +			...
> +		};
> +	};
> +};
> +
> +For more information about the children node, refer to the documents listed
> +above in the "Accepted children nodes" section.
> diff --git a/Documentation/devicetree/bindings/timer/ingenic,tcu.txt b/Documentation/devicetree/bindings/timer/ingenic,tcu.txt
> new file mode 100644
> index 000000000000..f910b7e96783
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/timer/ingenic,tcu.txt
> @@ -0,0 +1,41 @@
> +Ingenic JZ47xx SoCs Timer/Counter Unit driver
> +---------------------------------------------
> +
> +Required properties:
> +
> +- compatible : should be "ingenic,<socname>-tcu". Valid strings are:
> +  * ingenic,jz4740-tcu
> +  * ingenic,jz4770-tcu
> +  * ingenic,jz4780-tcu
> +- interrupt-parent : phandle of the TCU interrupt controller.
> +- interrupts : Specifies the interrupts the controller is connected to.
> +- clocks : List of phandle & clock specifiers for the TCU clocks.
> +- clock-names : List of name strings for the TCU clocks.
> +
> +Example:
> +
> +/ {
> +	tcu: mfd@10002000 {
> +		compatible = "ingenic,tcu", "simple-mfd", "syscon";
> +		reg = <0x10002000 0x1000>;
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +		ranges = <0x0 0x10002000 0x1000>;
> +
> +		tcu_timer: timer@10 {
> +			compatible = "ingenic,jz4740-tcu";
> +			reg = <0x10 0xff0>;
> +
> +			clocks = <&tcu_clk 0>, <&tcu_clk 1>, <&tcu_clk 2>, <&tcu_clk 3>,
> +					 <&tcu_clk 4>, <&tcu_clk 5>, <&tcu_clk 6>, <&tcu_clk 7>;
> +			clock-names = "timer0", "timer1", "timer2", "timer3",
> +						  "timer4", "timer5", "timer6", "timer7";
> +
> +			interrupt-parent = <&tcu_irq>;
> +			interrupts = <0 1 2 3 4 5 6 7>;
> +		};
> +	};
> +};
> +
> +For information about the top-level "ingenic,tcu" compatible node and other
> +children nodes, see Documentation/devicetree/bindings/mfd/ingenic,tcu.txt.
> 

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...