diff mbox

[1/4] doc/devicetree: Add Aspeed clock bindings

Message ID 1462797111-14271-2-git-send-email-joel@jms.id.au
State Changes Requested, archived
Headers show

Commit Message

Joel Stanley May 9, 2016, 12:31 p.m. UTC 
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
 .../devicetree/bindings/clock/aspeed-clock.txt     | 156 +++++++++++++++++++++
 1 file changed, 156 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/aspeed-clock.txt

Comments

Rob Herring (Arm) May 9, 2016, 8:30 p.m. UTC | #1 
On Mon, May 09, 2016 at 10:01:48PM +0930, Joel Stanley wrote:
> Signed-off-by: Joel Stanley <joel@jms.id.au>
> ---
>  .../devicetree/bindings/clock/aspeed-clock.txt     | 156 +++++++++++++++++++++
>  1 file changed, 156 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/clock/aspeed-clock.txt
> 
> diff --git a/Documentation/devicetree/bindings/clock/aspeed-clock.txt b/Documentation/devicetree/bindings/clock/aspeed-clock.txt
> new file mode 100644
> index 000000000000..968329406435
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/aspeed-clock.txt
> @@ -0,0 +1,156 @@
> +Device Tree Clock bindings for the Aspeed SoCs
> +
> +Aspeed SoCs have a fixed frequency input osciallator is used to create the PLL
> +and APB clocks. We can determine these frequencies by reading registers that
> +are set according to strapping bits.
> +
> +Forth generation boards
> +-----------------------
> +
> +eg, ast2400.
> +
> +CLKIN:
> + - compatible : Must be "fixed-clock"
> + - #clock-cells : Should be 0
> + - clock-frequency: 48e6, 25e6 or 24e6 depending on the input clock
> +
> +PLL:
> +
> +Required properties:
> + - compatible : Must be "aspeed,g4-hpll-clock"
> + - #clock-cells : Should be 0
> + - reg : Should contain registers location and length
> + - clocks : Should contain phandle + clock-specifier for the input clock (clkin)
> +
> +Optional properties:
> + - clock-output-names : Should contain clock name
> +
> +
> +APB:
> +
> +Required properties:
> + - compatible : Must be "aspeed,g4-apb-clock"
> + - #clock-cells : Should be 0
> + - reg : Should contain registers location and length
> + - clocks : Should contain phandle + clock-specifier for the h-pll
> +
> +Optional properties:
> + - clock-output-names : Should contain clock name
> +
> +
> +For example:
> +
> +	clk_clkin: clk_clkin {
> +		#clock-cells = <0>;
> +		compatible = "fixed-clock";
> +		clock-frequency = <48000000>;
> +	};
> +
> +	clk_hpll: clk_hpll {
> +		compatible = "aspeed,g4-hpll-clock";
> +		#clock-cells = <0>;
> +		reg = <0x1e6e2008 0x4>;
> +	};
> +
> +	clk_apb: clk_apb@1e6e2008 {
> +		#clock-cells = <0>;
> +		compatible = "aspeed,g4-apb-clock";
> +		reg = <0x1e6e2008 0x4>;

You have overlapping register regions which we try to avoid (it would 
through errors, but doesn't because of existing platforms).

Just define the h/w block controlling these clocks and support multiple 
clocks.

Is this really all the clocks the SOC has?

Rob
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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/clock/aspeed-clock.txt b/Documentation/devicetree/bindings/clock/aspeed-clock.txt
new file mode 100644
index 000000000000..968329406435
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/aspeed-clock.txt
@@ -0,0 +1,156 @@ 
+Device Tree Clock bindings for the Aspeed SoCs
+
+Aspeed SoCs have a fixed frequency input osciallator is used to create the PLL
+and APB clocks. We can determine these frequencies by reading registers that
+are set according to strapping bits.
+
+Forth generation boards
+-----------------------
+
+eg, ast2400.
+
+CLKIN:
+ - compatible : Must be "fixed-clock"
+ - #clock-cells : Should be 0
+ - clock-frequency: 48e6, 25e6 or 24e6 depending on the input clock
+
+PLL:
+
+Required properties:
+ - compatible : Must be "aspeed,g4-hpll-clock"
+ - #clock-cells : Should be 0
+ - reg : Should contain registers location and length
+ - clocks : Should contain phandle + clock-specifier for the input clock (clkin)
+
+Optional properties:
+ - clock-output-names : Should contain clock name
+
+
+APB:
+
+Required properties:
+ - compatible : Must be "aspeed,g4-apb-clock"
+ - #clock-cells : Should be 0
+ - reg : Should contain registers location and length
+ - clocks : Should contain phandle + clock-specifier for the h-pll
+
+Optional properties:
+ - clock-output-names : Should contain clock name
+
+
+For example:
+
+	clk_clkin: clk_clkin {
+		#clock-cells = <0>;
+		compatible = "fixed-clock";
+		clock-frequency = <48000000>;
+	};
+
+	clk_hpll: clk_hpll {
+		compatible = "aspeed,g4-hpll-clock";
+		#clock-cells = <0>;
+		reg = <0x1e6e2008 0x4>;
+	};
+
+	clk_apb: clk_apb@1e6e2008 {
+		#clock-cells = <0>;
+		compatible = "aspeed,g4-apb-clock";
+		reg = <0x1e6e2008 0x4>;
+		clocks = <&clk_hpll>;
+	};
+
+
+
+Fifth generation boards
+-----------------------
+
+eg, ast2500.
+
+CLKIN:
+Required properties:
+ - compatible : Must be "fixed-clock"
+ - #clock-cells : Should be 0
+ - clock-frequency: 25000000 or 24000000 depending on the input clock
+
+H-PLL:
+
+Required properties:
+ - compatible : Must be "aspeed,g5-hpll-clock"
+ - #clock-cells : Should be 0
+ - reg : Should contain registers location and length
+ - clocks : Should contain phandle + clock-specifier for the input clock (clkin)
+
+Optional properties:
+ - clock-output-names : Should contain clock name
+
+AHB:
+
+Required properties:
+ - compatible : Must be "aspeed,g5-ahb-clock"
+ - #clock-cells : Should be 0
+ - reg : Should contain registers location and length
+ - clocks : Should contain phandle + clock-specifier for the the h-pll
+
+Optional properties:
+ - clock-output-names : Should contain clock name
+
+APB:
+
+Required properties:
+ - compatible : Must be "aspeed,g4-apb-clock"
+ - #clock-cells : Should be 0
+ - reg : Should contain registers location and length
+ - clocks : Should contain phandle + clock-specifier for the the h-pll
+
+Optional properties:
+ - clock-output-names : Should contain clock name
+
+For example:
+	clk_clkin: clk_clkin@1e6e2070 {
+		#clock-cells = <0>;
+		compatible = "aspeed,g5-clkin-clock";
+		reg = <0x1e6e2070 0x04>;
+	};
+
+	clk_hpll: clk_hpll@1e6e2024 {
+		#clock-cells = <0>;
+		compatible = "aspeed,g5-hpll-clock";
+		reg = <0x1e6e2024 0x4>;
+		clocks = <&clk_clkin>;
+	};
+
+	clk_ahb: clk_ahb@1e6e2070 {
+		#clock-cells = <0>;
+		compatible = "aspeed,g5-ahb-clock";
+		reg = <0x1e6e2070 0x4>;
+		clocks = <&clk_hpll>;
+	};
+
+	clk_apb: clk_apb@1e6e2008 {
+		#clock-cells = <0>;
+		compatible = "aspeed,g5-apb-clock";
+		reg = <0x1e6e2008 0x4>;
+		clocks = <&clk_hpll>;
+	};
+
+Common clocks
+-------------
+
+UART:
+
+All supported boards have a uart clock that is derived from a 24MHz reference.
+We have a clock driver for it as there is a register in the SCU that controls
+weather it will be divided down by 13 or not.
+
+Required properties:
+ - compatible : Must be "aspeed,uart-clock"
+ - #clock-cells : Should be 0
+ - reg : Should contain registers location and length
+
+For example:
+
+	clk_uart: clk_uart@1e6e2008 {
+		#clock-cells = <0>;
+		compatible = "aspeed,uart-clock";
+		reg = <0x1e6e202c 0x4>;
+	};