Documentation/devicetree/bindings/cpufreq/ti-cpufreq.txt

   1 TI CPUFreq and OPP bindings
   2 ================================
   3
   4 Certain TI SoCs, like those in the am335x, am437x, am57xx, and dra7xx
   5 families support different OPPs depending on the silicon variant in use.
   6 The ti-cpufreq driver can use revision and an efuse value from the SoC to
   7 provide the OPP framework with supported hardware information. This is
   8 used to determine which OPPs from the operating-points-v2 table get enabled
   9 when it is parsed by the OPP framework.
  10
  11 Required properties:
  12 --------------------
  13 In 'cpus' nodes:
  14 - operating-points-v2: Phandle to the operating-points-v2 table to use.
  15
  16 In '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
  23 Optional 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
  28 For 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
  36 Example:
  37 --------
  38
  39 /* From arch/arm/boot/dts/am33xx.dtsi */
  40 cpus {
  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  */
  61 cpu0_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 };