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 SoCs
  19 - syscon: A phandle pointing to a syscon node representing the control module
  20           register space of the SoC.
  21
  22 Optional properties:
  23 --------------------
  24 For each opp entry in 'operating-points-v2' table:
  25 - opp-supported-hw: Two bitfields indicating:
  26         1. Which revision of the SoC the OPP is supported by
  27         2. Which eFuse bits indicate this OPP is available
  28
  29         A bitwise AND is performed against these values and if any bit
  30         matches, the OPP gets enabled.
  31
  32 Example:
  33 --------
  34
  35 /* From arch/arm/boot/dts/am33xx.dtsi */
  36 cpus {
  37         #address-cells = <1>;
  38         #size-cells = <0>;
  39         cpu@0 {
  40                 compatible = "arm,cortex-a8";
  41                 device_type = "cpu";
  42                 reg = <0>;
  43
  44                 operating-points-v2 = <&cpu0_opp_table>;
  45
  46                 clocks = <&dpll_mpu_ck>;
  47                 clock-names = "cpu";
  48
  49                 clock-latency = <300000>; /* From omap-cpufreq driver */
  50         };
  51 };
  52
  53 /*
  54  * cpu0 has different OPPs depending on SoC revision and some on revisions
  55  * 0x2 and 0x4 have eFuse bits that indicate if they are available or not
  56  */
  57 cpu0_opp_table: opp-table {
  58         compatible = "operating-points-v2-ti-cpu";
  59         syscon = <&scm_conf>;
  60
  61         /*
  62          * The three following nodes are marked with opp-suspend
  63          * because they can not be enabled simultaneously on a
  64          * single SoC.
  65          */
  66         opp50-300000000 {
  67                 opp-hz = /bits/ 64 <300000000>;
  68                 opp-microvolt = <950000 931000 969000>;
  69                 opp-supported-hw = <0x06 0x0010>;
  70                 opp-suspend;
  71         };
  72
  73         opp100-275000000 {
  74                 opp-hz = /bits/ 64 <275000000>;
  75                 opp-microvolt = <1100000 1078000 1122000>;
  76                 opp-supported-hw = <0x01 0x00FF>;
  77                 opp-suspend;
  78         };
  79
  80         opp100-300000000 {
  81                 opp-hz = /bits/ 64 <300000000>;
  82                 opp-microvolt = <1100000 1078000 1122000>;
  83                 opp-supported-hw = <0x06 0x0020>;
  84                 opp-suspend;
  85         };
  86
  87         opp100-500000000 {
  88                 opp-hz = /bits/ 64 <500000000>;
  89                 opp-microvolt = <1100000 1078000 1122000>;
  90                 opp-supported-hw = <0x01 0xFFFF>;
  91         };
  92
  93         opp100-600000000 {
  94                 opp-hz = /bits/ 64 <600000000>;
  95                 opp-microvolt = <1100000 1078000 1122000>;
  96                 opp-supported-hw = <0x06 0x0040>;
  97         };
  98
  99         opp120-600000000 {
 100                 opp-hz = /bits/ 64 <600000000>;
 101                 opp-microvolt = <1200000 1176000 1224000>;
 102                 opp-supported-hw = <0x01 0xFFFF>;
 103         };
 104
 105         opp120-720000000 {
 106                 opp-hz = /bits/ 64 <720000000>;
 107                 opp-microvolt = <1200000 1176000 1224000>;
 108                 opp-supported-hw = <0x06 0x0080>;
 109         };
 110
 111         oppturbo-720000000 {
 112                 opp-hz = /bits/ 64 <720000000>;
 113                 opp-microvolt = <1260000 1234800 1285200>;
 114                 opp-supported-hw = <0x01 0xFFFF>;
 115         };
 116
 117         oppturbo-800000000 {
 118                 opp-hz = /bits/ 64 <800000000>;
 119                 opp-microvolt = <1260000 1234800 1285200>;
 120                 opp-supported-hw = <0x06 0x0100>;
 121         };
 122
 123         oppnitro-1000000000 {
 124                 opp-hz = /bits/ 64 <1000000000>;
 125                 opp-microvolt = <1325000 1298500 1351500>;
 126                 opp-supported-hw = <0x04 0x0200>;
 127         };
 128 };