On 01/08/2022 20:46, Matej Vasilevski wrote:
> Add second clock phandle to specify the timestamping clock.
> You can even use the same clock as the core, or define a fixed-clock
> if you need something custom.
>
> Signed-off-by: Matej Vasilevski <matej.vasilevski@xxxxxxxxx>
> ---
> .../bindings/net/can/ctu,ctucanfd.yaml | 23 +++++++++++++++----
> 1 file changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/net/can/ctu,ctucanfd.yaml b/Documentation/devicetree/bindings/net/can/ctu,ctucanfd.yaml
> index 4635cb96fc64..90390530f909 100644
> --- a/Documentation/devicetree/bindings/net/can/ctu,ctucanfd.yaml
> +++ b/Documentation/devicetree/bindings/net/can/ctu,ctucanfd.yaml
> @@ -44,9 +44,23 @@ properties:
>
> clocks:
> description: |
> - phandle of reference clock (100 MHz is appropriate
> - for FPGA implementation on Zynq-7000 system).
> - maxItems: 1
> + Phandle of reference clock (100 MHz is appropriate for FPGA
> + implementation on Zynq-7000 system). If you wish to use timestamps
> + from the controller, add a second phandle with the clock used for
> + timestamping. The timestamping clock is optional, if you don't
> + add it here, the driver will use the primary clock frequency for
> + timestamp calculations. If you need something custom, define
> + a fixed-clock oscillator and reference it.
This should not be a guide how to write DTS, but description of
hardware. The references to driver are also not really appropriate in
the bindings (are you 100% sure that all other operating systems and SW
have driver which behaves like this...)
> + minItems: 1
> + items:
> + - description: core clock
> + - description: timestamping clock
> +
> + clock-names:
> + minItems: 1
> + items:
> + - const: core-clk
> + - const: ts-clk
>
> required:
> - compatible
> @@ -61,6 +75,7 @@ examples:
> ctu_can_fd_0: can@43c30000 {
> compatible = "ctu,ctucanfd";
> interrupts = <0 30 4>;
> - clocks = <&clkc 15>;
> + clocks = <&clkc 15>, <&clkc 16>;
> + clock-names = "core-clk", "ts-clk";
> reg = <0x43c30000 0x10000>;
> };
Best regards,
Krzysztof
