xref: /OK3568_Linux_fs/kernel/Documentation/devicetree/bindings/cpufreq/nvidia,tegra20-cpufreq.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunBinding for NVIDIA Tegra20 CPUFreq
2*4882a593Smuzhiyun==================================
3*4882a593Smuzhiyun
4*4882a593SmuzhiyunRequired properties:
5*4882a593Smuzhiyun- clocks: Must contain an entry for the CPU clock.
6*4882a593Smuzhiyun  See ../clocks/clock-bindings.txt for details.
7*4882a593Smuzhiyun- operating-points-v2: See ../bindings/opp/opp.txt for details.
8*4882a593Smuzhiyun- #cooling-cells: Should be 2. See ../thermal/thermal-cooling-devices.yaml for details.
9*4882a593Smuzhiyun
10*4882a593SmuzhiyunFor each opp entry in 'operating-points-v2' table:
11*4882a593Smuzhiyun- opp-supported-hw: Two bitfields indicating:
12*4882a593Smuzhiyun	On Tegra20:
13*4882a593Smuzhiyun	1. CPU process ID mask
14*4882a593Smuzhiyun	2. SoC speedo ID mask
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun	On Tegra30:
17*4882a593Smuzhiyun	1. CPU process ID mask
18*4882a593Smuzhiyun	2. CPU speedo ID mask
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun	A bitwise AND is performed against these values and if any bit
21*4882a593Smuzhiyun	matches, the OPP gets enabled.
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun- opp-microvolt: CPU voltage triplet.
24*4882a593Smuzhiyun
25*4882a593SmuzhiyunOptional properties:
26*4882a593Smuzhiyun- cpu-supply: Phandle to the CPU power supply.
27*4882a593Smuzhiyun
28*4882a593SmuzhiyunExample:
29*4882a593Smuzhiyun	regulators {
30*4882a593Smuzhiyun		cpu_reg: regulator0 {
31*4882a593Smuzhiyun			regulator-name = "vdd_cpu";
32*4882a593Smuzhiyun		};
33*4882a593Smuzhiyun	};
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun	cpu0_opp_table: opp_table0 {
36*4882a593Smuzhiyun		compatible = "operating-points-v2";
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun		opp@456000000 {
39*4882a593Smuzhiyun			clock-latency-ns = <125000>;
40*4882a593Smuzhiyun			opp-microvolt = <825000 825000 1125000>;
41*4882a593Smuzhiyun			opp-supported-hw = <0x03 0x0001>;
42*4882a593Smuzhiyun			opp-hz = /bits/ 64 <456000000>;
43*4882a593Smuzhiyun		};
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun		...
46*4882a593Smuzhiyun	};
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun	cpus {
49*4882a593Smuzhiyun		cpu@0 {
50*4882a593Smuzhiyun			compatible = "arm,cortex-a9";
51*4882a593Smuzhiyun			clocks = <&tegra_car TEGRA20_CLK_CCLK>;
52*4882a593Smuzhiyun			operating-points-v2 = <&cpu0_opp_table>;
53*4882a593Smuzhiyun			cpu-supply = <&cpu_reg>;
54*4882a593Smuzhiyun			#cooling-cells = <2>;
55*4882a593Smuzhiyun		};
56*4882a593Smuzhiyun	};
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