Re: [U-Boot] [PATCH] armv8/fsl-layerscape: fdt: remove SYSCLK frequency fixup for ls1012a

8 Feb 2017


      On 02/07/2017 07:30 PM, Y.B. Lu wrote:
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-----Original Message-----
From: york sun
Sent: Wednesday, February 08, 2017 1:03 AM
To: Scott Wood; Y.B. Lu; u-boot@lists.denx.de
Cc: Albert Aribaud; Z.Q. Hou
Subject: Re: [U-Boot] [PATCH] armv8/fsl-layerscape: fdt: remove SYSCLK
frequency fixup for ls1012a
On 01/20/2017 05:13 PM, york sun wrote:
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Then a proper fix would be check the clock name or compatible. If none
of them exists, we should fix the device tree first.
Yangbo,
Can you fix the code to check clock name or compatible?
York
[Lu Yangbo-B47093] Hi York, do you mean check the clock name or compatible to make sure it's sysclk and then fix it?
Scott's patch added coreclock node also with compatible 'fixed-clock'.
https://patchwork.kernel.org/patch/9536515/
If we check clock name, I found most names with 'fixed-clock' compatible are 'sysclk', but some are not.
fsl-ls1012a-frdm.dts:
        sys_mclk: clock-mclk {
                compatible = "fixed-clock";
                #clock-cells = <0>;
                clock-frequency = <25000000>;
        };
fsl-ls1012a-qds.dts:
        sys_mclk: clock-mclk {
                compatible = "fixed-clock";
                #clock-cells = <0>;
                clock-frequency = <24576000>;
        };
Clearly "fixed-clock" is not a good compatible string to search for. It 
just tells you this clock is fixed in frequency. It doesn't tell you if 
a clock is system clock.
Can you find this clock by its name? If you need to unify the device 
tree, it may be the time now.
York