xref: /freebsd/sys/contrib/device-tree/Bindings/cpufreq/ti-cpufreq.txt (revision 5f4c09dd85bff675e0ca63c55ea3c517e0fddfcc)
1TI CPUFreq and OPP bindings
2================================
3
4Certain TI SoCs, like those in the am335x, am437x, am57xx, and dra7xx
5families support different OPPs depending on the silicon variant in use.
6The ti-cpufreq driver can use revision and an efuse value from the SoC to
7provide the OPP framework with supported hardware information. This is
8used to determine which OPPs from the operating-points-v2 table get enabled
9when it is parsed by the OPP framework.
10
11Required properties:
12--------------------
13In 'cpus' nodes:
14- operating-points-v2: Phandle to the operating-points-v2 table to use.
15
16In 'operating-points-v2' table:
17- compatible: Should be
18	- 'operating-points-v2-ti-cpu' for am335x, am43xx, and dra7xx/am57xx,
19	  omap34xx, omap36xx and am3517 SoCs
20- syscon: A phandle pointing to a syscon node representing the control module
21	  register space of the SoC.
22
23Optional properties:
24--------------------
25- "vdd-supply", "vbb-supply": to define two regulators for dra7xx
26- "cpu0-supply", "vbb-supply": to define two regulators for omap36xx
27
28For each opp entry in 'operating-points-v2' table:
29- opp-supported-hw: Two bitfields indicating:
30	1. Which revision of the SoC the OPP is supported by
31	2. Which eFuse bits indicate this OPP is available
32
33	A bitwise AND is performed against these values and if any bit
34	matches, the OPP gets enabled.
35
36Example:
37--------
38
39/* From arch/arm/boot/dts/am33xx.dtsi */
40cpus {
41	#address-cells = <1>;
42	#size-cells = <0>;
43	cpu@0 {
44		compatible = "arm,cortex-a8";
45		device_type = "cpu";
46		reg = <0>;
47
48		operating-points-v2 = <&cpu0_opp_table>;
49
50		clocks = <&dpll_mpu_ck>;
51		clock-names = "cpu";
52
53		clock-latency = <300000>; /* From omap-cpufreq driver */
54	};
55};
56
57/*
58 * cpu0 has different OPPs depending on SoC revision and some on revisions
59 * 0x2 and 0x4 have eFuse bits that indicate if they are available or not
60 */
61cpu0_opp_table: opp-table {
62	compatible = "operating-points-v2-ti-cpu";
63	syscon = <&scm_conf>;
64
65	/*
66	 * The three following nodes are marked with opp-suspend
67	 * because they can not be enabled simultaneously on a
68	 * single SoC.
69	 */
70	opp50-300000000 {
71		opp-hz = /bits/ 64 <300000000>;
72		opp-microvolt = <950000 931000 969000>;
73		opp-supported-hw = <0x06 0x0010>;
74		opp-suspend;
75	};
76
77	opp100-275000000 {
78		opp-hz = /bits/ 64 <275000000>;
79		opp-microvolt = <1100000 1078000 1122000>;
80		opp-supported-hw = <0x01 0x00FF>;
81		opp-suspend;
82	};
83
84	opp100-300000000 {
85		opp-hz = /bits/ 64 <300000000>;
86		opp-microvolt = <1100000 1078000 1122000>;
87		opp-supported-hw = <0x06 0x0020>;
88		opp-suspend;
89	};
90
91	opp100-500000000 {
92		opp-hz = /bits/ 64 <500000000>;
93		opp-microvolt = <1100000 1078000 1122000>;
94		opp-supported-hw = <0x01 0xFFFF>;
95	};
96
97	opp100-600000000 {
98		opp-hz = /bits/ 64 <600000000>;
99		opp-microvolt = <1100000 1078000 1122000>;
100		opp-supported-hw = <0x06 0x0040>;
101	};
102
103	opp120-600000000 {
104		opp-hz = /bits/ 64 <600000000>;
105		opp-microvolt = <1200000 1176000 1224000>;
106		opp-supported-hw = <0x01 0xFFFF>;
107	};
108
109	opp120-720000000 {
110		opp-hz = /bits/ 64 <720000000>;
111		opp-microvolt = <1200000 1176000 1224000>;
112		opp-supported-hw = <0x06 0x0080>;
113	};
114
115	oppturbo-720000000 {
116		opp-hz = /bits/ 64 <720000000>;
117		opp-microvolt = <1260000 1234800 1285200>;
118		opp-supported-hw = <0x01 0xFFFF>;
119	};
120
121	oppturbo-800000000 {
122		opp-hz = /bits/ 64 <800000000>;
123		opp-microvolt = <1260000 1234800 1285200>;
124		opp-supported-hw = <0x06 0x0100>;
125	};
126
127	oppnitro-1000000000 {
128		opp-hz = /bits/ 64 <1000000000>;
129		opp-microvolt = <1325000 1298500 1351500>;
130		opp-supported-hw = <0x04 0x0200>;
131	};
132};
133