Re: [v2 1/2] arm64: dts: ls1028a: Update the clock providers for the Mali DP500

From: Shawn Guo
Date: Mon Oct 07 2019 - 08:32:55 EST


On Fri, Sep 20, 2019 at 04:34:18PM +0800, Wen He wrote:
> In order to maximise performance of the LCD Controller's 64-bit AXI
> bus, for any give speed bin of the device, the AXI master interface
> clock(ACLK) clock can be up to CPU_frequency/2, which is already
> capable of optimal performance. In general, ACLK is always expected
> to be equal to CPU_frequency/2. APB slave interface clock(PCLK) and
> Main processing clock(PCLK) both are tied to the same clock as ACLK.
>
> This change followed the LS1028A Architecture Specification Manual.
>
> Signed-off-by: Wen He <wen.he_1@xxxxxxx>

@Leo, agree?

Shawn

> ---
> change in v2:
> - add details commit description for this change.
> - v1: Link: https://lore.kernel.org/patchwork/patch/1119145/
>
> arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi | 17 ++---------------
> 1 file changed, 2 insertions(+), 15 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi b/arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi
> index 72b9a75976a1..51fa8f57fdac 100644
> --- a/arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi
> +++ b/arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi
> @@ -86,20 +86,6 @@
> clocks = <&osc_27m>;
> };
>
> - aclk: clock-axi {
> - compatible = "fixed-clock";
> - #clock-cells = <0>;
> - clock-frequency = <650000000>;
> - clock-output-names= "aclk";
> - };
> -
> - pclk: clock-apb {
> - compatible = "fixed-clock";
> - #clock-cells = <0>;
> - clock-frequency = <650000000>;
> - clock-output-names= "pclk";
> - };
> -
> reboot {
> compatible ="syscon-reboot";
> regmap = <&dcfg>;
> @@ -679,7 +665,8 @@
> interrupts = <0 222 IRQ_TYPE_LEVEL_HIGH>,
> <0 223 IRQ_TYPE_LEVEL_HIGH>;
> interrupt-names = "DE", "SE";
> - clocks = <&dpclk 0>, <&aclk>, <&aclk>, <&pclk>;
> + clocks = <&dpclk 0>, <&clockgen 2 2>, <&clockgen 2 2>,
> + <&clockgen 2 2>;
> clock-names = "pxlclk", "mclk", "aclk", "pclk";
> arm,malidp-output-port-lines = /bits/ 8 <8 8 8>;
> arm,malidp-arqos-value = <0xd000d000>;
> --
> 2.17.1
>