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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/devicetree/bindings/clock/nuvoton,npcm750-clk.txt | |
parent | Initial commit. (diff) | |
download | linux-upstream/5.10.209.tar.xz linux-upstream/5.10.209.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | Documentation/devicetree/bindings/clock/nuvoton,npcm750-clk.txt | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/clock/nuvoton,npcm750-clk.txt b/Documentation/devicetree/bindings/clock/nuvoton,npcm750-clk.txt new file mode 100644 index 000000000..f82064546 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/nuvoton,npcm750-clk.txt @@ -0,0 +1,100 @@ +* Nuvoton NPCM7XX Clock Controller + +Nuvoton Poleg BMC NPCM7XX contains an integrated clock controller, which +generates and supplies clocks to all modules within the BMC. + +External clocks: + +There are six fixed clocks that are generated outside the BMC. All clocks are of +a known fixed value that cannot be changed. clk_refclk, clk_mcbypck and +clk_sysbypck are inputs to the clock controller. +clk_rg1refck, clk_rg2refck and clk_xin are external clocks suppling the +network. They are set on the device tree, but not used by the clock module. The +network devices use them directly. +Example can be found below. + +All available clocks are defined as preprocessor macros in: +dt-bindings/clock/nuvoton,npcm7xx-clock.h +and can be reused as DT sources. + +Required Properties of clock controller: + + - compatible: "nuvoton,npcm750-clk" : for clock controller of Nuvoton + Poleg BMC NPCM750 + + - reg: physical base address of the clock controller and length of + memory mapped region. + + - #clock-cells: should be 1. + +Example: Clock controller node: + + clk: clock-controller@f0801000 { + compatible = "nuvoton,npcm750-clk"; + #clock-cells = <1>; + reg = <0xf0801000 0x1000>; + clock-names = "refclk", "sysbypck", "mcbypck"; + clocks = <&clk_refclk>, <&clk_sysbypck>, <&clk_mcbypck>; + }; + +Example: Required external clocks for network: + + /* external reference clock */ + clk_refclk: clk-refclk { + compatible = "fixed-clock"; + #clock-cells = <0>; + clock-frequency = <25000000>; + clock-output-names = "refclk"; + }; + + /* external reference clock for cpu. float in normal operation */ + clk_sysbypck: clk-sysbypck { + compatible = "fixed-clock"; + #clock-cells = <0>; + clock-frequency = <800000000>; + clock-output-names = "sysbypck"; + }; + + /* external reference clock for MC. float in normal operation */ + clk_mcbypck: clk-mcbypck { + compatible = "fixed-clock"; + #clock-cells = <0>; + clock-frequency = <800000000>; + clock-output-names = "mcbypck"; + }; + + /* 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: GMAC controller node that consumes two clocks: a generated clk by the +clock controller and a fixed clock from DT (clk_rg1refck). + + ethernet0: ethernet@f0802000 { + compatible = "snps,dwmac"; + reg = <0xf0802000 0x2000>; + interrupts = <0 14 4>; + interrupt-names = "macirq"; + clocks = <&clk_rg1refck>, <&clk NPCM7XX_CLK_AHB>; + clock-names = "stmmaceth", "clk_gmac"; + }; |