Re: [PATCH v2 1/2] Doc: bindings: Add binding doc for nxp system counter timer

From: Rob Herring
Date: Tue Dec 18 2018 - 12:03:41 EST


On Wed, Dec 12, 2018 at 05:28:23AM +0000, Jacky Bai wrote:
> Add the binding doc for nxp system counter timer module.
>
> Signed-off-by: Bai Ping <ping.bai@xxxxxxx>
> ---
> change v1->v2
> - remove the blank line at EOF
> ---
> .../devicetree/bindings/timer/nxp,sysctr_timer.txt | 26 ++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/timer/nxp,sysctr_timer.txt
>
> diff --git a/Documentation/devicetree/bindings/timer/nxp,sysctr_timer.txt b/Documentation/devicetree/bindings/timer/nxp,sysctr_timer.txt
> new file mode 100644
> index 0000000..21f1527
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/timer/nxp,sysctr_timer.txt
> @@ -0,0 +1,26 @@
> +NXP System Counter Module(sys_ctr)
> +
> +The system counter(sys_ctr) is a programmable system counter which provides
> +a shared time base to Cortex A15, A7, A53, A73, etc. it is intended for use in
> +applications where the counter is always powered and support multiple,
> +unrelated clocks.
> +
> +Required properties:
> +
> +- compatible : should be "nxp,sysctr-timer"

Only 1 version? Should be SoC specific.

> +- reg : Specifies the base physical address and size of the comapre

s/comapre/compare/

> + frame and the counter control, read & compare.
> +- interrupts : should be the compare frames' interrupt
> +- clock-frequency : Specifies the counter clock frequency.
> +
> +Example:
> +
> + system_counter: timer@306a0000 {
> + compatible = "nxp,sysctr-timer";
> + reg = <0x0 0x306a0000 0x0 0x10000>, /* system-counter-rd base */
> + <0x0 0x306b0000 0x0 0x10000>, /* system-counter-cmp base */
> + <0x0 0x306c0000 0x0 0x10000>; /* system-counter-ctrl base */

Are these really 64K in length? That wastes virtual space which can be
important on 32-bit systems.

> + clock-frequency = <8000000>;
> + interrupts = <GIC_SPI 47 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 48 IRQ_TYPE_LEVEL_HIGH>;
> + };
> --
> 1.9.1
>