Re: [PATCH 5/5] dt-bindings: timer: Add CLINT bindings

[Sean Anderson <seanga2@gmail.com>]

On 5/21/20 9:45 AM, Anup Patel wrote:
> We add DT bindings documentation for CLINT device.
> 
> Signed-off-by: Anup Patel <anup.patel@wdc.com>
> ---
>  .../bindings/timer/sifive,clint.txt           | 33 +++++++++++++++++++
>  1 file changed, 33 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/timer/sifive,clint.txt
> 
> diff --git a/Documentation/devicetree/bindings/timer/sifive,clint.txt b/Documentation/devicetree/bindings/timer/sifive,clint.txt
> new file mode 100644
> index 000000000000..cae2dad1223a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/timer/sifive,clint.txt
> @@ -0,0 +1,33 @@
> +SiFive Core Local Interruptor (CLINT)
> +-------------------------------------
> +
> +SiFive (and other RISC-V) SOCs include an implementation of the SiFive Core
> +Local Interruptor (CLINT) for M-mode timer and inter-processor interrupts.
> +
> +It directly connects to the timer and inter-processor interrupt lines of
> +various HARTs (or CPUs) so RISC-V per-HART (or per-CPU) local interrupt
> +controller is the parent interrupt controller for CLINT device.
> +
> +The clock frequency of CLINT is specified via "timebase-frequency" DT
> +property of "/cpus" DT node. The "timebase-frequency" DT property is
> +described in: Documentation/devicetree/bindings/riscv/cpus.yaml
> +
> +Required properties:
> +- compatible : "sifive,clint-1.0.0" and a string identifying the actual
> +  detailed implementation in case that specific bugs need to be worked around.

Should the "riscv,clint0" compatible string be documented here? This
peripheral is not really specific to sifive, as it is present in most
rocket-chip cores.

> +- reg : Should contain 1 register range (address and length).
> +- interrupts-extended : Specifies which HARTs (or CPUs) are connected to
> +  the CLINT.  Each node pointed to should be a riscv,cpu-intc node, which
> +  has a riscv node as parent.
> +
> +Example:
> +
> +	clint@2000000 {
> +		compatible = "sifive,clint-1.0.0", "sifive,fu540-c000-clint";
> +		interrupts-extended = <
> +			&cpu1-intc 3 &cpu1-intc 7
> +			&cpu2-intc 3 &cpu2-intc 7
> +			&cpu3-intc 3 &cpu3-intc 7
> +			&cpu4-intc 3 &cpu4-intc 7>;
> +		reg = <0x2000000 0x4000000>;
> +	};
> 

--Sean