1 Binding for ST's CPUFreq driver
2 ===============================
3
4 ST's CPUFreq driver attempts to read 'process' and 'version' attributes
5 from the SoC, then supplies the OPP framework with 'prop' and 'supported
6 hardware' information respectively. The framework is then able to read
7 the DT and operate in the usual way.
8
9 Frequency Scaling only
10 ----------------------
11
12 No vendor specific driver required for this.
13
14 Located in CPU's node:
15
16 - operating-points : [See: ../power/opp-v1.yaml]
17
18 Example [safe]
19 --------------
20
21 cpus {
22 cpu@0 {
23 /* kHz uV */
24 operating-points = <1500000 0
25 1200000 0
26 800000 0
27 500000 0>;
28 };
29 };
30
31 Dynamic Voltage and Frequency Scaling (DVFS)
32 --------------------------------------------
33
34 This requires the ST CPUFreq driver to supply 'process' and 'version' info.
35
36 Located in CPU's node:
37
38 - operating-points-v2 : [See ../power/opp-v2.yaml]
39
40 Example [unsafe]
41 ----------------
42
43 cpus {
44 cpu@0 {
45 operating-points-v2 = <&cpu0_opp_table>;
46 };
47 };
48
49 cpu0_opp_table: opp_table {
50 compatible = "operating-points-v2";
51
52 /* ############################################################### */
53 /* # WARNING: Do not attempt to copy/replicate these nodes, # */
54 /* # they are only to be supplied by the bootloader !!! # */
55 /* ############################################################### */
56 opp0 {
57 /* Major Minor Substrate */
58 /* 2 all all */
59 opp-supported-hw = <0x00000004 0xffffffff 0xffffffff>;
60 opp-hz = /bits/ 64 <1500000000>;
61 clock-latency-ns = <10000000>;
62
63 opp-microvolt-pcode0 = <1200000>;
64 opp-microvolt-pcode1 = <1200000>;
65 opp-microvolt-pcode2 = <1200000>;
66 opp-microvolt-pcode3 = <1200000>;
67 opp-microvolt-pcode4 = <1170000>;
68 opp-microvolt-pcode5 = <1140000>;
69 opp-microvolt-pcode6 = <1100000>;
70 opp-microvolt-pcode7 = <1070000>;
71 };
72
73 opp1 {
74 /* Major Minor Substrate */
75 /* all all all */
76 opp-supported-hw = <0xffffffff 0xffffffff 0xffffffff>;
77 opp-hz = /bits/ 64 <1200000000>;
78 clock-latency-ns = <10000000>;
79
80 opp-microvolt-pcode0 = <1110000>;
81 opp-microvolt-pcode1 = <1150000>;
82 opp-microvolt-pcode2 = <1100000>;
83 opp-microvolt-pcode3 = <1080000>;
84 opp-microvolt-pcode4 = <1040000>;
85 opp-microvolt-pcode5 = <1020000>;
86 opp-microvolt-pcode6 = <980000>;
87 opp-microvolt-pcode7 = <930000>;
88 };
89 };
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