Added device tree binding documentation for Nuvoton NPCM7xx clocks.
Signed-off-by: Tomer Maimon <[email protected]>
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.../bindings/clock/nuvoton,npcm7xx-clk.txt | 84 ++++++++++++++++++++++
1 file changed, 84 insertions(+)
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Documentation/devicetree/bindings/clock/nuvoton,npcm7xx-clk.txt
diff --git a/Documentation/devicetree/bindings/clock/nuvoton,npcm7xx-clk.txt
b/Documentation/devicetree/bindings/clock/nuvoton,npcm7xx-clk.txt
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index 000000000000..1ba1945d3616
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/nuvoton,npcm7xx-clk.txt
@@ -0,0 +1,84 @@
+* Nuvoton NPCM7XX Clock Controller
+
+Nuvoton Poleg BMC NPCM7XX contain integrated clock
+controller, which generates and supplies clock to all modules within the BMC.
+
+Required Properties:
+
+- compatible: should be one of following:
+ - "nuvoton,npcm750-clk" : for clock controller of Nuvoton
+ Poleg BMC NPCM750
+
+- reg: physical base address of the controller and length of memory mapped
+ region.
+
+
+- #clock-cells: should be 1.
+
+All available clocks are defined as preprocessor macros in
+dt-bindings/clock/nuvoton,npcm7xx-clock.h header and can beused in device tree
+sources.
+
+External clocks:
+
+There are several clocks that are generated outside the BMC. All clocks are of
+a known fixed value that cannot be chagned. Therefor these values are hard
coded
+inside the driver and registered on init.
+
+The clock modules contains 4 PLL, 20 dividers and 11 muxes. All these settings
+are set before Linux boot and are not to be altered by the Linux. This driver
is
+used only to read the values clocks, not to set them.
+
+In addition to the clock driver, there are 3 external clocks suppling the
+network, which are of fixed values, set on on the device tree, but not used by
+ the clock module. Example can be found below.
+
+Example: Clock controller node:
+
+ clk: clock-controller@f0801000 {
+ compatible = "nuvoton,npcm750-clk";
+ #clock-cells = <1>;
+ clock-controller;
+ reg = <0xf0801000 0x1000>;
+ status = "okay";
+ };
+
+Example: Required external clocks for network:
+
+ /* external clock signal rg1refck, supplied by the phy */
+ clk_rg1refck: clk_rg1refck {
+ compatible = "fixed-clock";
+ #clock-cells = <0>;
+ clock-frequency = <125000000>;
+ clock-output-names = "clk_rg1refck";
+ };
+
+ /* external clock signal rg2refck, supplied by the phy */
+ clk_rg2refck: clk_rg2refck {
+ compatible = "fixed-clock";
+ #clock-cells = <0>;
+ clock-frequency = <125000000>;
+ clock-output-names = "clk_rg2refck";
+ };
+
+ clk_xin: clk_xin {
+ compatible = "fixed-clock";
+ #clock-cells = <0>;
+ clock-frequency = <50000000>;
+ clock-output-names = "clk_xin";
+ };
+
+Example: UART controller node that consumes the clock generated by the clock
+ controller (refer to the standard clock bindings for information about
+ "clocks" and "clock-names" properties):
+
+ uart0: serial@e2900000 {
+ compatible = "Nuvoton,s5pv210-uart";
+ reg = <0xe2900000 0x400>;
+ interrupt-parent = <&vic1>;
+ interrupts = <10>;
+ clock-names = "uart", "clk_uart_baud0",
+ "clk_uart_baud1";
+ clocks = <&clocks UART0>, <&clocks UART0>,
+ <&clocks SCLK_UART0>;
+ };
--
2.14.1
