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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/nvidia,tegra124-car.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/nvidia,tegra124-car.txt | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/clock/nvidia,tegra124-car.txt b/Documentation/devicetree/bindings/clock/nvidia,tegra124-car.txt new file mode 100644 index 000000000..7f02fb4ca --- /dev/null +++ b/Documentation/devicetree/bindings/clock/nvidia,tegra124-car.txt @@ -0,0 +1,107 @@ +NVIDIA Tegra124 and Tegra132 Clock And Reset Controller + +This binding uses the common clock binding: +Documentation/devicetree/bindings/clock/clock-bindings.txt + +The CAR (Clock And Reset) Controller on Tegra is the HW module responsible +for muxing and gating Tegra's clocks, and setting their rates. + +Required properties : +- compatible : Should be "nvidia,tegra124-car" or "nvidia,tegra132-car" +- reg : Should contain CAR registers location and length +- clocks : Should contain phandle and clock specifiers for two clocks: + the 32 KHz "32k_in", and the board-specific oscillator "osc". +- #clock-cells : Should be 1. + In clock consumers, this cell represents the clock ID exposed by the + CAR. The assignments may be found in the header files + <dt-bindings/clock/tegra124-car-common.h> (which covers IDs common + to Tegra124 and Tegra132) and <dt-bindings/clock/tegra124-car.h> + (for Tegra124-specific clocks). +- #reset-cells : Should be 1. + In clock consumers, this cell represents the bit number in the CAR's + array of CLK_RST_CONTROLLER_RST_DEVICES_* registers. +- nvidia,external-memory-controller : phandle of the EMC driver. + +The node should contain a "emc-timings" subnode for each supported RAM type (see +field RAM_CODE in register PMC_STRAPPING_OPT_A). + +Required properties for "emc-timings" nodes : +- nvidia,ram-code : Should contain the value of RAM_CODE this timing set + is used for. + +Each "emc-timings" node should contain a "timing" subnode for every supported +EMC clock rate. + +Required properties for "timing" nodes : +- clock-frequency : Should contain the memory clock rate to which this timing +relates. +- nvidia,parent-clock-frequency : Should contain the rate at which the current +parent of the EMC clock should be running at this timing. +- clocks : Must contain an entry for each entry in clock-names. + See ../clocks/clock-bindings.txt for details. +- clock-names : Must include the following entries: + - emc-parent : the clock that should be the parent of the EMC clock at this +timing. + +Example SoC include file: + +/ { + tegra_car: clock@60006000 { + compatible = "nvidia,tegra124-car"; + reg = <0x60006000 0x1000>; + #clock-cells = <1>; + #reset-cells = <1>; + nvidia,external-memory-controller = <&emc>; + }; + + usb@c5004000 { + clocks = <&tegra_car TEGRA124_CLK_USB2>; + }; +}; + +Example board file: + +/ { + clocks { + compatible = "simple-bus"; + #address-cells = <1>; + #size-cells = <0>; + + osc: clock@0 { + compatible = "fixed-clock"; + reg = <0>; + #clock-cells = <0>; + clock-frequency = <112400000>; + }; + + clk_32k: clock@1 { + compatible = "fixed-clock"; + reg = <1>; + #clock-cells = <0>; + clock-frequency = <32768>; + }; + }; + + &tegra_car { + clocks = <&clk_32k> <&osc>; + }; + + clock@60006000 { + emc-timings-3 { + nvidia,ram-code = <3>; + + timing-12750000 { + clock-frequency = <12750000>; + nvidia,parent-clock-frequency = <408000000>; + clocks = <&tegra_car TEGRA124_CLK_PLL_P>; + clock-names = "emc-parent"; + }; + timing-20400000 { + clock-frequency = <20400000>; + nvidia,parent-clock-frequency = <408000000>; + clocks = <&tegra_car TEGRA124_CLK_PLL_P>; + clock-names = "emc-parent"; + }; + }; + }; +}; |