Re: [PATCH 09/10] dts: versatile: add clock tree

On Fri, May 23, 2014 at 8:28 AM, Linus Walleij [off-list ref] wrote:

On Tue, May 20, 2014 at 11:09 PM, Rob Herring [off-list ref] wrote:

quoted

From: Rob Herring <redacted>

The versatile dts is missing any clock data. Add the clocks.

It is not clear from the documentation where pclk comes from, so for
now it is a dummy clock which is sufficient for things to work.

AFAICT (from experiments and measurements on some boards, during which
I destroyed some boards) that is actually just the 24MHz clock right off.

quoted

Signed-off-by: Rob Herring <redacted>

quoted

+       core-module@10000000 {
+               compatible = "arm,core-module-versatile";
+               reg = <0x10000000 0x200>;
+
+               osc24M: oscillator@24M {
+                       #clock-cells = <0>;
+                       compatible = "fixed-clock";
+                       clock-frequency = <24000000>;
+               };

Please follow the naming convention from the Integrator DTS, I am
pretty sure this is a chrystal:

        /* 24 MHz chrystal on the core module */
        xtal24mhz: xtal24mhz@24M {
                #clock-cells = <0>;
                compatible = "fixed-clock";
                clock-frequency = <24000000>;
        };

I'm not too sure I'm happy about this naming convention (yours or
mine). Following that node names are generic, it should probably be
just clk or clock. The unit address is a bit of an abuse as there is
no reg property, but we do need some way to make it unique. I don't
see the point of having the frequency in the name twice either.

quoted

+               /* OSC1 on AB, OSC4 on PB */
+               osc1: cm_aux_osc@24M {
+                       #clock-cells = <0>;
+                       compatible = "arm,versatile-cm-auxosc";
+                       clocks = <&osc24M>;
+               };

Name xtal, also: why is this inside the core module node?
You're explicitly saying it is on the PB (platform baseboard)
and *not* on the core module!

But it is not a crystal. It is an output of the clock chip. This
follows what you have for integrator in name and location and it is
part of the AB core-module.

Rob
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