Subject: [PATCH] ARM: davinci: da850 evm: update clock rate for UART 1/2 DT nodes

From: [email-masked] (Sekhar Nori)
Date: Thu, 28 Feb 2013 16:09:47 +0530

Prakash,

On 2/19/2013 2:02 PM, Manjunathappa, Prakash wrote:
> DT kernel with latest of denx SPL U-boot boots with garbled UART
> logs. This is because in U-boot UART2 gets sourced by PLL0_SYSCLK2
> configured for 150MHz. But later in kernel UART2 gets mapped to
> PLL1_SYSCLK2 and is configured for 132MHz not for 150MHz.
> 
> PLL1 is configured for 264MHz to support mDDR on the EVM. That is
> memory controller driving mDDR can be configured for 150MHz and
> mDDR it self can operate at 132MHz.
> 
> So override UART1 and UART2 DT node clock-frequency property with
> rate available on da850 EVM.
> 
> Signed-off-by: Manjunathappa, Prakash <[email-masked]>

How about dropping the clock-frequency attribute altogether? of_serial.c
seems to be falling back on clk apis if frequency is not passed and that
should make the kernel work with all versions of U-Boot.

Thanks,
Sekhar

> ---
>  arch/arm/boot/dts/da850-evm.dts |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/boot/dts/da850-evm.dts b/arch/arm/boot/dts/da850-evm.dts
> index f712fb6..c359872 100644
> --- a/arch/arm/boot/dts/da850-evm.dts
> +++ b/arch/arm/boot/dts/da850-evm.dts
> @@ -22,9 +22,11 @@
>  			status = "okay";
>  		};
>  		serial1: serial at 1d0c000 {
> +			clock-frequency = <132000000>;
>  			status = "okay";
>  		};
>  		serial2: serial at 1d0d000 {
> +			clock-frequency = <132000000>;
>  			status = "okay";
>  		};
>  		rtc0: rtc at 1c23000 {
>