[PATCH v8] clk: corenet: Adds the clock binding

[PATCH v8] clk: corenet: Adds the clock binding

[Tang Yuantian]

From: Tang Yuantian <yuantian.tang-KZfg59tc24xl57MIdRCFDg@public.gmane.org>

Adds the clock bindings for Freescale PowerPC CoreNet platforms

Signed-off-by: Tang Yuantian <Yuantian.Tang-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
Signed-off-by: Li Yang <leoli-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
---
v8:
	- added clock-frequency property description
	- fixed whitespace and tab mixing issue
v7:
	- refined some properties' definitions
v6:
	- splited the previous patch into 2 parts, one is for binding(this one),
	  the other is for DTS modification(will submit once this gets accepted)
	- fixed typo
	- refined #clock-cells and clock-output-names properties
	- removed fixed-clock compatible string
v5:
	- refine the binding document
	- update the compatible string
v4:
	- add binding document
	- update compatible string
	- update the reg property
v3:
	- fix typo
v2:
	- add t4240, b4420, b4860 support
	- remove pll/4 clock from p2041, p3041 and p5020 board

 .../devicetree/bindings/clock/corenet-clock.txt    | 133 +++++++++++++++++++++
 1 file changed, 133 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/corenet-clock.txt

diff --git a/Documentation/devicetree/bindings/clock/corenet-clock.txt b/Documentation/devicetree/bindings/clock/corenet-clock.txt
new file mode 100644
index 0000000..abb0493
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/corenet-clock.txt
@@ -0,0 +1,133 @@
+* Clock Block on Freescale CoreNet Platforms
+
+Freescale CoreNet chips take primary clocking input from the external
+SYSCLK signal. The SYSCLK input (frequency) is multiplied using
+multiple phase locked loops (PLL) to create a variety of frequencies
+which can then be passed to a variety of internal logic, including
+cores and peripheral IP blocks.
+Please refer to the Reference Manual for details.
+
+1. Clock Block Binding
+
+Required properties:
+- compatible: Should contain a specific clock block compatible string
+	and a single chassis clock compatible string.
+	Clock block strings include, but not limited to, one of the:
+	* "fsl,p2041-clockgen"
+	* "fsl,p3041-clockgen"
+	* "fsl,p4080-clockgen"
+	* "fsl,p5020-clockgen"
+	* "fsl,p5040-clockgen"
+	* "fsl,t4240-clockgen"
+	* "fsl,b4420-clockgen"
+	* "fsl,b4860-clockgen"
+	Chassis clock strings include:
+	* "fsl,qoriq-clockgen-1.0": for chassis 1.0 clocks
+	* "fsl,qoriq-clockgen-2.0": for chassis 2.0 clocks
+- reg: Offset and length of the clock register set
+
+Recommended properties:
+- clock-frequency: Input system clock frequency. Must be present
+	if the device has sub-nodes.
+- ranges: Allows valid translation between child's address space and
+	parent's. Must be present if the device has sub-nodes.
+- #address-cells: Specifies the number of cells used to represent
+	physical base addresses.  Must be present if the device has
+	sub-nodes and set to 1 if present
+- #size-cells: Specifies the number of cells used to represent
+	the size of an address. Must be present if the device has
+	sub-nodes and set to 1 if present
+
+2. Clock Provider/Consumer Binding
+
+Most of the bindings are from the common clock binding[1].
+ [1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- compatible : Should include one of the following:
+	* "fsl,qoriq-core-pll-1.0" for core PLL clocks (v1.0)
+	* "fsl,qoriq-core-pll-2.0" for core PLL clocks (v2.0)
+	* "fsl,qoriq-core-mux-1.0" for core mux clocks (v1.0)
+	* "fsl,qoriq-core-mux-2.0" for core mux clocks (v2.0)
+	* "fsl,qoriq-sysclk-1.0": for input system clock (v1.0).
+		It takes parent's clock as its clock.
+	* "fsl,qoriq-sysclk-2.0": for input system clock (v2.0).
+		It takes parent's clock as its clock.
+- #clock-cells: From common clock binding. The number of cells in a
+	clock-specifier. Should be <0> for "fsl,qoriq-sysclk-[1,2].0"
+	clocks, or <1> for "fsl,qoriq-core-pll-[1,2].0" clocks.
+	For "fsl,qoriq-core-pll-[1,2].0" clocks, the single
+	clock-specifier cell may take the following values:
+	* 0 - equal to the PLL frequency
+	* 1 - equal to the PLL frequency divided by 2
+	* 2 - equal to the PLL frequency divided by 4
+
+Recommended properties:
+- clocks: Should be the phandle of input parent clock
+- clock-names: From common clock binding, indicates the clock name
+- clock-output-names: From common clock binding, indicates the names of
+	output clocks
+- reg: Should be the offset and length of clock block base address.
+	The length should be 4.
+
+Example for clock block and clock provider:
+/ {
+	clockgen: global-utilities@e1000 {
+		compatible = "fsl,p5020-clockgen", "fsl,qoriq-clockgen-1.0";
+		ranges = <0x0 0xe1000 0x1000>;
+		clock-frequency = <0>;
+		reg = <0xe1000 0x1000>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		sysclk: sysclk {
+			#clock-cells = <0>;
+			compatible = "fsl,qoriq-sysclk-1.0";
+			clock-output-names = "sysclk";
+		}
+
+		pll0: pll0@800 {
+			#clock-cells = <1>;
+			reg = <0x800 0x4>;
+			compatible = "fsl,qoriq-core-pll-1.0";
+			clocks = <&sysclk>;
+			clock-output-names = "pll0", "pll0-div2";
+		};
+
+		pll1: pll1@820 {
+			#clock-cells = <1>;
+			reg = <0x820 0x4>;
+			compatible = "fsl,qoriq-core-pll-1.0";
+			clocks = <&sysclk>;
+			clock-output-names = "pll1", "pll1-div2";
+		};
+
+		mux0: mux0@0 {
+			#clock-cells = <0>;
+			reg = <0x0 0x4>;
+			compatible = "fsl,qoriq-core-mux-1.0";
+			clocks = <&pll0 0>, <&pll0 1>, <&pll1 0>, <&pll1 1>;
+			clock-names = "pll0", "pll0-div2", "pll1", "pll1-div2";
+			clock-output-names = "cmux0";
+		};
+
+		mux1: mux1@20 {
+			#clock-cells = <0>;
+			reg = <0x20 0x4>;
+			compatible = "fsl,qoriq-core-mux-1.0";
+			clocks = <&pll0 0>, <&pll0 1>, <&pll1 0>, <&pll1 1>;
+			clock-names = "pll0", "pll0-div2", "pll1", "pll1-div2";
+			clock-output-names = "cmux1";
+		};
+	};
+  }
+
+Example for clock consumer:
+
+/ {
+	cpu0: PowerPC,e5500@0 {
+		...
+		clocks = <&mux0>;
+		...
+	};
+  }
-- 
1.8.0


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Re: [PATCH v8] clk: corenet: Adds the clock binding

[Scott Wood]

On Fri, 2014-01-10 at 10:29 +0800, Tang Yuantian wrote:
> +- reg: Offset and length of the clock register set

"offset" into what?  The containing node is not within the scope of this
binding.

I know that plenty of other bindings are worded this way, and I wouldn't
hold up acceptance if this were the only issue, but it ought to be fixed
to say something like "reg: resource zero represents the clock register
set".

> +Recommended properties:
> +- clock-frequency: Input system clock frequency. Must be present
> +	if the device has sub-nodes.

Why only "if the device has sub-nodes"?

> +       * "fsl,qoriq-sysclk-1.0": for input system clock (v1.0).
> +               It takes parent's clock as its clock.
> +       * "fsl,qoriq-sysclk-2.0": for input system clock (v2.0).
> +               It takes parent's clock as its clock.

s/parent's clock/parent's clock-frequency/ since the parent isn't
actually exposing a clock as per the clock bindings.

> +Example for clock block and clock provider:
> +/ {
> +	clockgen: global-utilities@e1000 {
> +		compatible = "fsl,p5020-clockgen", "fsl,qoriq-clockgen-1.0";
> +		ranges = <0x0 0xe1000 0x1000>;
> +		clock-frequency = <0>;

It'd be better to show a real clock-frequency here -- this is an example
for the node as the OS sees it, not what goes in the dts as an input to
U-Boot.

-Scott


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RE: [PATCH v8] clk: corenet: Adds the clock binding

[Yuantian Tang]

Thanks for your review.

Thanks,
Yuantian

> -----Original Message-----
> From: Wood Scott-B07421
> Sent: 2014年1月11日 星期六 4:20
> To: Tang Yuantian-B29983
> Cc: Wood Scott-B07421; galak@kernel.crashing.org; mark.rutland@arm.com;
> devicetree@vger.kernel.org; linuxppc-dev@lists.ozlabs.org; Li Yang-Leo-
> R58472
> Subject: Re: [PATCH v8] clk: corenet: Adds the clock binding
> 
> On Fri, 2014-01-10 at 10:29 +0800, Tang Yuantian wrote:
> > +- reg: Offset and length of the clock register set
> 
> "offset" into what?  The containing node is not within the scope of this
> binding.
> 
> I know that plenty of other bindings are worded this way, and I wouldn't
> hold up acceptance if this were the only issue, but it ought to be fixed
> to say something like "reg: resource zero represents the clock register
> set".
> 
OK, will refine it.

> > +Recommended properties:
> > +- clock-frequency: Input system clock frequency. Must be present
> > +	if the device has sub-nodes.
> 
> Why only "if the device has sub-nodes"?
> 
OK, will fix it.

> > +       * "fsl,qoriq-sysclk-1.0": for input system clock (v1.0).
> > +               It takes parent's clock as its clock.
> > +       * "fsl,qoriq-sysclk-2.0": for input system clock (v2.0).
> > +               It takes parent's clock as its clock.
> 
> s/parent's clock/parent's clock-frequency/ since the parent isn't
> actually exposing a clock as per the clock bindings.
> 
OK.

> > +Example for clock block and clock provider:
> > +/ {
> > +	clockgen: global-utilities@e1000 {
> > +		compatible = "fsl,p5020-clockgen", "fsl,qoriq-clockgen-1.0";
> > +		ranges = <0x0 0xe1000 0x1000>;
> > +		clock-frequency = <0>;
> 
> It'd be better to show a real clock-frequency here -- this is an example
> for the node as the OS sees it, not what goes in the dts as an input to
> U-Boot.
> 
OK, will remove it.

> -Scott
>