Re: [PATCH 2/2] ARM: dts: enable init rate for clock

From: Doug Anderson
Date: Tue Oct 07 2014 - 13:03:29 EST


Kever,

On Tue, Oct 7, 2014 at 2:33 AM, Kever Yang <kever.yang@xxxxxxxxxxxxxx> wrote:
> We need to initialize PLL rate and some of bus clock rate while
> kernel init, for there is no other module will do that.
>
> Signed-off-by: Kever Yang <kever.yang@xxxxxxxxxxxxxx>
> ---
>
> arch/arm/boot/dts/rk3288.dtsi | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/arch/arm/boot/dts/rk3288.dtsi b/arch/arm/boot/dts/rk3288.dtsi
> index 874e66d..2f4519b 100644
> --- a/arch/arm/boot/dts/rk3288.dtsi
> +++ b/arch/arm/boot/dts/rk3288.dtsi
> @@ -455,6 +455,16 @@
> rockchip,grf = <&grf>;
> #clock-cells = <1>;
> #reset-cells = <1>;
> + assigned-clocks = <&cru PLL_GPLL>, <&cru PLL_CPLL>,
> + <&cru PLL_NPLL>, <&cru ACLK_CPU>,
> + <&cru HCLK_CPU>, <&cru PCLK_CPU>,
> + <&cru ACLK_PERI>, <&cru HCLK_PERI>,
> + <&cru PCLK_PERI>;
> + assigned-clock-rates = <594000000>, <400000000>,
> + <500000000>, <300000000>,

When I boot up, I see that ACLK_CPU was 297000000. You specified
300000000. Did you expect to get 300? If you expected 297, I think
you should put 297. If you expected 300 then we have some debugging
to do. Note: I'm not quite sure how you'd expect to get 300 given
that none of the PLLs divide evenly to 300...


> + <150000000>, <75000000>,

Similarly, I see 148500000, 74250000

> + <300000000>, <150000000>,

297000000, 148500000

> + <75000000>;

74250000

> };
>
> grf: syscon@ff770000 {
> --
> 1.9.1
>
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