From: nsekhar@ti•com (Sekhar Nori)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] ARM: davinci: da850 evm: update clock rate for UART 1/2 DT nodes
Date: Thu, 28 Feb 2013 16:09:47 +0530 [thread overview]
Message-ID: <512F33F3.9070203@ti.com> (raw)
In-Reply-To: <1361262734-8540-1-git-send-email-prakash.pm@ti.com>
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 <prakash.pm@ti•com>
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 {
>
next prev parent reply other threads:[~2013-02-28 10:39 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-19 8:32 [PATCH] ARM: davinci: da850 evm: update clock rate for UART 1/2 DT nodes Manjunathappa, Prakash
2013-02-28 10:39 ` Sekhar Nori [this message]
2013-03-15 13:26 ` Manjunathappa, Prakash
2013-03-15 14:37 ` Sekhar Nori
2013-04-09 5:31 ` Manjunathappa, Prakash
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