[OpenWrt-Devel] [PATCH] staging: mt7621-dts: correct various clock frequencies.

[John Crispin]

On 23/06/18 22:49, Rosen Penev wrote:
> From: NeilBrown <neil at brown.name>
>
> The MT7621 documentation says that the sys clock - also known
> as OCP clock for the Open Core Protocol - can be configured to
> 1/3 or 1/4 of the CPU clock.
> Testing on my hardware, using the fact that the SPI clock is
> based on the OCP clock and measuring transfer rates, shows
> a clock of a little over 200MHz with a CPU clock of 900MHz.
> So assume 1/4 is the default.
>
> Also, the nor-flash in the gbpc1 is documented as accepting 50MHz
> for request requests, and higher for other requests.  So set
> maximum to 50MHz.
>
> Signed-off-by: NeilBrown <neil at brown.name>
> Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>

NAK, these backports caused too many regressions already, we will get 
the whole lot and test it when we bump the target.
     John
> ---
>   target/linux/ramips/dts/GB-PC1.dts  | 8 +++++++-
>   target/linux/ramips/dts/mt7621.dtsi | 4 ++--
>   2 files changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/target/linux/ramips/dts/GB-PC1.dts b/target/linux/ramips/dts/GB-PC1.dts
> index 3b29d335b9..db6c3a86b0 100644
> --- a/target/linux/ramips/dts/GB-PC1.dts
> +++ b/target/linux/ramips/dts/GB-PC1.dts
> @@ -71,7 +71,7 @@
>   		#size-cells = <1>;
>   		compatible = "jedec,spi-nor";
>   		reg = <0>;
> -		spi-max-frequency = <10000000>;
> +		spi-max-frequency = <50000000>;
>   		m25p,chunked-io = <32>;
>   
>   		partition at 0 {
> @@ -99,6 +99,12 @@
>   	};
>   };
>   
> +&sysclock {
> +	compatible = "fixed-clock";
> +	/* This is normally 1/4 of cpuclock */
> +	clock-frequency = <225000000>;
> +};
> +
>   &cpuclock {
>   	compatible = "fixed-clock";
>   	clock-frequency = <900000000>;
> diff --git a/target/linux/ramips/dts/mt7621.dtsi b/target/linux/ramips/dts/mt7621.dtsi
> index 0655e35301..dd8e87f7ce 100644
> --- a/target/linux/ramips/dts/mt7621.dtsi
> +++ b/target/linux/ramips/dts/mt7621.dtsi
> @@ -45,8 +45,8 @@
>   		#clock-cells = <0>;
>   		compatible = "fixed-clock";
>   
> -		/* FIXME: there should be way to detect this */
> -		clock-frequency = <50000000>;
> +		/* This is normally 1/4 of cpuclock */
> +		clock-frequency = <220000000>;
>   	};
>   
>   


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