Re: [PATCH 2/2] clk: clps711x: Add DT bindings documentation

On Sun, Jun 01, 2014 at 10:55:22AM +0100, Alexander Shiyan wrote:

Huh? Why is this called "cpufreq" what is this the frequency of,
exactly?

Is this an input or an output?

Cheers,
Mark.

+- #clock-cells: Should be <1>.
+
+The clock consumer should specify the desired clock by having the clock
+ID in its "clocks" phandle cell. See include/dt-bindings/clock/clps711x-clock.h
+for the full list of CLPS711X clock IDs.
+
+Example:
+	clks: clks at 80000000 {
+		#clock-cells = <1>;
+		compatible = "cirrus,ep7312-clk", "cirrus,clps711x-clk";
+		reg = <0x80000000 0xc000>;
+		cpufreq = <73728000>;
+	};
-- 
1.8.5.5

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Mon, 2 Jun 2014 09:56:51 +0100 ?? Mark Rutland [off-list ref]:

On Sun, Jun 01, 2014 at 10:55:22AM +0100, Alexander Shiyan wrote:

quoted

This patch adds DT binding documentation for the Cirrus Logic
CLPS711X-based CPUs clock subsystem.

Signed-off-by: Alexander Shiyan <redacted>
---
 .../devicetree/bindings/clock/clps711x-clock.txt      | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/clps711x-clock.txt

diff --git a/Documentation/devicetree/bindings/clock/clps711x-clock.txt b/Documentation/devicetree/bindings/clock/clps711x-clock.txt
new file mode 100644
index 0000000..0fdf3c9
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/clps711x-clock.txt

@@ -0,0 +1,19 @@
+* Clock bindings for the Cirrus Logic CLPS711X CPUs
+
+Required properties:
+- compatible  : Shall contain "cirrus,clps711x-clk".
+- reg         : Address of the internal register set.
+- cpufreq     : Factory set default frequency in HZ.

Huh? Why is this called "cpufreq" what is this the frequency of,
exactly?

Is this an input or an output?

Modern CLPS711X CPUs support PLL reprogramming, while for older processors,
this procedure is not possible and the CPU clock is set to a fixed value. Thus if the
value of the PLL multiplier is not correct (missing), we use a fixed CPU frequency
of the processor, described in DT, which allows us to use the driver for the new and
old versions of this CPU.

---