On 23/06/2019 14:38, Anson.Huang@xxxxxxx wrote:
> From: Anson Huang <Anson.Huang@xxxxxxx>
>
> Systems which use platform driver model for clock driver require the
> clock frequency to be supplied via device tree when system counter
> driver is enabled.
>
> This is necessary as in the platform driver model the of_clk operations
> do not work correctly because system counter driver is initialized in
> early phase of system boot up, and clock driver using platform driver
> model is NOT ready at that time, it will cause system counter driver
> initialization failed.
>
> Add the optinal clock-frequency to the device tree bindings of the NXP
> system counter, so the frequency can be handed in and the of_clk
> operations can be skipped.
>
> Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
> ---
> Changes since V1:
> - improve commit log, no content change.
> ---
> Documentation/devicetree/bindings/timer/nxp,sysctr-timer.txt | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/timer/nxp,sysctr-timer.txt b/Documentation/devicetree/bindings/timer/nxp,sysctr-timer.txt
> index d576599..c9907a0 100644
> --- a/Documentation/devicetree/bindings/timer/nxp,sysctr-timer.txt
> +++ b/Documentation/devicetree/bindings/timer/nxp,sysctr-timer.txt
> @@ -14,6 +14,11 @@ Required properties:
> - clocks : Specifies the counter clock.
> - clock-names: Specifies the clock's name of this module
>
> +Optional properties:
> +
> +- clock-frequency : Specifies system counter clock frequency and indicates system
> + counter driver to skip clock operations.
> +
Shouldn't it be required and mutually exclusive with clocks/clock-names?
> Example:
>
> system_counter: timer@306a0000 {
> @@ -22,4 +27,5 @@ Example:
> clocks = <&clk_8m>;
> clock-names = "per";
> interrupts = <GIC_SPI 47 IRQ_TYPE_LEVEL_HIGH>;
> + clock-frequency = <8333333>;
> };
>
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