Date: Sun, 9 Nov 2014 13:34:48 -0800
From: =?utf-8?B?U8O2cmVu?= Brinkmann <soren.brinkmann@xilinx.com>
To: Peter Crosthwaite <crosthwaitepeter@gmail.com>
CC: <linux-kernel@vger.kernel.org>, <michals@xilinx.com>, <sorenb@xilinx.com>,
        <steven.wang@digilentinc.com>
Subject: Re: [PATCH 1/2] arm: dts: zynq: Move crystal freq. to board level
References: <1415504283-31321-1-git-send-email-crosthwaite.peter@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Disposition: inline
In-Reply-To: <1415504283-31321-1-git-send-email-crosthwaite.peter@gmail.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Message-ID: <38537ddd8ce845cd9929db4ffcb33031@BN1AFFO11FD006.protection.gbl>
Sender: linux-kernel-owner@vger.kernel.org

On Sun, 2014-11-09 at 01:38PM +1000, Peter Crosthwaite wrote:
> The fact that all supported boards use the same 33MHz crystal is a
> co-incidence. The Zynq PS support a range of crystal freqs so the
> hardcoded setting should be removed from the dtsi. Re-implement it
> on the board level.
> 
> This prepares support for Zynq boards with different crystal
> frequencies (e.g. the Digilent ZYBO).

Even with the 33MHz in the dtsi you can override it on the board-level.
Just like the 'status' property is overriden in board dts files.

> 
> Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
> 
> ---
> Im guessing long term this should be converted to a fixed clock. But
> I think this at least steps in that direction.

I was against that since it makes juggling with clock names more
difficult. The problem is that the CCF uses a global name space of clock
names. Not having the oscillator as fixed-clock in DT removed that
additional complexity. But it would be possible, I guess.

> ---
>  arch/arm/boot/dts/zynq-7000.dtsi      | 1 -
>  arch/arm/boot/dts/zynq-parallella.dts | 4 ++++
>  arch/arm/boot/dts/zynq-zc702.dts      | 4 ++++
>  arch/arm/boot/dts/zynq-zc706.dts      | 4 ++++
>  arch/arm/boot/dts/zynq-zed.dts        | 4 ++++
>  5 files changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/boot/dts/zynq-7000.dtsi b/arch/arm/boot/dts/zynq-7000.dtsi
> index ce2ef5b..ee3e5d6 100644
> --- a/arch/arm/boot/dts/zynq-7000.dtsi
> +++ b/arch/arm/boot/dts/zynq-7000.dtsi
> @@ -243,7 +243,6 @@
>  			clkc: clkc@100 {
>  				#clock-cells = <1>;
>  				compatible = "xlnx,ps7-clkc";
> -				ps-clk-frequency = <33333333>;
>  				fclk-enable = <0>;
>  				clock-output-names = "armpll", "ddrpll", "iopll", "cpu_6or4x",
>  						"cpu_3or2x", "cpu_2x", "cpu_1x", "ddr2x", "ddr3x",
> diff --git a/arch/arm/boot/dts/zynq-parallella.dts b/arch/arm/boot/dts/zynq-parallella.dts
> index e1f51ca..cd84d45 100644
> --- a/arch/arm/boot/dts/zynq-parallella.dts
> +++ b/arch/arm/boot/dts/zynq-parallella.dts
> @@ -83,3 +83,7 @@
>  &uart1 {
>  	status = "okay";
>  };
> +
> +&clkc {
> +	ps-clk-frequency = <33333333>;
> +};
> diff --git a/arch/arm/boot/dts/zynq-zc702.dts b/arch/arm/boot/dts/zynq-zc702.dts
> index 94e2cda..24dcece 100644
> --- a/arch/arm/boot/dts/zynq-zc702.dts
> +++ b/arch/arm/boot/dts/zynq-zc702.dts
> @@ -135,3 +135,7 @@
>  &uart1 {
>  	status = "okay";
>  };
> +
> +&clkc {
> +	ps-clk-frequency = <33333333>;
> +};
> diff --git a/arch/arm/boot/dts/zynq-zc706.dts b/arch/arm/boot/dts/zynq-zc706.dts
> index a8bbdfb..7b88399 100644
> --- a/arch/arm/boot/dts/zynq-zc706.dts
> +++ b/arch/arm/boot/dts/zynq-zc706.dts
> @@ -114,3 +114,7 @@
>  &uart1 {
>  	status = "okay";
>  };
> +
> +&clkc {
> +	ps-clk-frequency = <33333333>;
> +};
> diff --git a/arch/arm/boot/dts/zynq-zed.dts b/arch/arm/boot/dts/zynq-zed.dts
> index 697779a..4662da2 100644
> --- a/arch/arm/boot/dts/zynq-zed.dts
> +++ b/arch/arm/boot/dts/zynq-zed.dts
> @@ -46,3 +46,7 @@
>  &uart1 {
>  	status = "okay";
>  };
> +
> +&clkc {
> +	ps-clk-frequency = <33333333>;
> +};

I think we currently have the nodes more or less in alphabetical order.
I'd prefer if we maintained that.

Other than that:
Acked-by: Soren Brinkmann <soren.brinkmann@xilinx.com>

	Soren
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/