summaryrefslogtreecommitdiffstats
path: root/Documentation/devicetree/bindings/clock/nvidia,tegra124-car.txt
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/devicetree/bindings/clock/nvidia,tegra124-car.txt
parentInitial commit. (diff)
downloadlinux-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 'Documentation/devicetree/bindings/clock/nvidia,tegra124-car.txt')
-rw-r--r--Documentation/devicetree/bindings/clock/nvidia,tegra124-car.txt107
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";
+ };
+ };
+ };
+};