Documentation/devicetree/bindings/arm/cci.txt

   1 =======================================================
   2 ARM CCI cache coherent interconnect binding description
   3 =======================================================
   4
   5 ARM multi-cluster systems maintain intra-cluster coherency through a
   6 cache coherent interconnect (CCI) that is capable of monitoring bus
   7 transactions and manage coherency, TLB invalidations and memory barriers.
   8
   9 It allows snooping and distributed virtual memory message broadcast across
  10 clusters, through memory mapped interface, with a global control register
  11 space and multiple sets of interface control registers, one per slave
  12 interface.
  13
  14 Bindings for the CCI node follow the ePAPR standard, available from:
  15
  16 www.power.org/documentation/epapr-version-1-1/
  17
  18 with the addition of the bindings described in this document which are
  19 specific to ARM.
  20
  21 * CCI interconnect node
  22
  23         Description: Describes a CCI cache coherent Interconnect component
  24
  25         Node name must be "cci".
  26         Node's parent must be the root node /, and the address space visible
  27         through the CCI interconnect is the same as the one seen from the
  28         root node (ie from CPUs perspective as per DT standard).
  29         Every CCI node has to define the following properties:
  30
  31         - compatible
  32                 Usage: required
  33                 Value type: <string>
  34                 Definition: must be set to
  35                             "arm,cci-400"
  36
  37         - reg
  38                 Usage: required
  39                 Value type: Integer cells. A register entry, expressed as a pair
  40                             of cells, containing base and size.
  41                 Definition: A standard property. Specifies base physical
  42                             address of CCI control registers common to all
  43                             interfaces.
  44
  45         - ranges:
  46                 Usage: required
  47                 Value type: Integer cells. An array of range entries, expressed
  48                             as a tuple of cells, containing child address,
  49                             parent address and the size of the region in the
  50                             child address space.
  51                 Definition: A standard property. Follow rules in the ePAPR for
  52                             hierarchical bus addressing. CCI interfaces
  53                             addresses refer to the parent node addressing
  54                             scheme to declare their register bases.
  55
  56         CCI interconnect node can define the following child nodes:
  57
  58         - CCI control interface nodes
  59
  60                 Node name must be "slave-if".
  61                 Parent node must be CCI interconnect node.
  62
  63                 A CCI control interface node must contain the following
  64                 properties:
  65
  66                 - compatible
  67                         Usage: required
  68                         Value type: <string>
  69                         Definition: must be set to
  70                                     "arm,cci-400-ctrl-if"
  71
  72                 - interface-type:
  73                         Usage: required
  74                         Value type: <string>
  75                         Definition: must be set to one of {"ace", "ace-lite"}
  76                                     depending on the interface type the node
  77                                     represents.
  78
  79                 - reg:
  80                         Usage: required
  81                         Value type: Integer cells. A register entry, expressed
  82                                     as a pair of cells, containing base and
  83                                     size.
  84                         Definition: the base address and size of the
  85                                     corresponding interface programming
  86                                     registers.
  87
  88         - CCI PMU node
  89
  90                 Parent node must be CCI interconnect node.
  91
  92                 A CCI pmu node must contain the following properties:
  93
  94                 - compatible
  95                         Usage: required
  96                         Value type: <string>
  97                         Definition: must be "arm,cci-400-pmu"
  98
  99                 - reg:
 100                         Usage: required
 101                         Value type: Integer cells. A register entry, expressed
 102                                     as a pair of cells, containing base and
 103                                     size.
 104                         Definition: the base address and size of the
 105                                     corresponding interface programming
 106                                     registers.
 107
 108                 - interrupts:
 109                         Usage: required
 110                         Value type: Integer cells. Array of interrupt specifier
 111                                     entries, as defined in
 112                                     ../interrupt-controller/interrupts.txt.
 113                         Definition: list of counter overflow interrupts, one per
 114                                     counter. The interrupts must be specified
 115                                     starting with the cycle counter overflow
 116                                     interrupt, followed by counter0 overflow
 117                                     interrupt, counter1 overflow interrupt,...
 118                                     ,counterN overflow interrupt.
 119
 120                                     The CCI PMU has an interrupt signal for each
 121                                     counter. The number of interrupts must be
 122                                     equal to the number of counters.
 123
 124 * CCI interconnect bus masters
 125
 126         Description: masters in the device tree connected to a CCI port
 127                      (inclusive of CPUs and their cpu nodes).
 128
 129         A CCI interconnect bus master node must contain the following
 130         properties:
 131
 132         - cci-control-port:
 133                 Usage: required
 134                 Value type: <phandle>
 135                 Definition: a phandle containing the CCI control interface node
 136                             the master is connected to.
 137
 138 Example:
 139
 140         cpus {
 141                 #size-cells = <0>;
 142                 #address-cells = <1>;
 143
 144                 CPU0: cpu@0 {
 145                         device_type = "cpu";
 146                         compatible = "arm,cortex-a15";
 147                         cci-control-port = <&cci_control1>;
 148                         reg = <0x0>;
 149                 };
 150
 151                 CPU1: cpu@1 {
 152                         device_type = "cpu";
 153                         compatible = "arm,cortex-a15";
 154                         cci-control-port = <&cci_control1>;
 155                         reg = <0x1>;
 156                 };
 157
 158                 CPU2: cpu@100 {
 159                         device_type = "cpu";
 160                         compatible = "arm,cortex-a7";
 161                         cci-control-port = <&cci_control2>;
 162                         reg = <0x100>;
 163                 };
 164
 165                 CPU3: cpu@101 {
 166                         device_type = "cpu";
 167                         compatible = "arm,cortex-a7";
 168                         cci-control-port = <&cci_control2>;
 169                         reg = <0x101>;
 170                 };
 171
 172         };
 173
 174         dma0: dma@3000000 {
 175                 compatible = "arm,pl330", "arm,primecell";
 176                 cci-control-port = <&cci_control0>;
 177                 reg = <0x0 0x3000000 0x0 0x1000>;
 178                 interrupts = <10>;
 179                 #dma-cells = <1>;
 180                 #dma-channels = <8>;
 181                 #dma-requests = <32>;
 182         };
 183
 184         cci@2c090000 {
 185                 compatible = "arm,cci-400";
 186                 #address-cells = <1>;
 187                 #size-cells = <1>;
 188                 reg = <0x0 0x2c090000 0 0x1000>;
 189                 ranges = <0x0 0x0 0x2c090000 0x10000>;
 190
 191                 cci_control0: slave-if@1000 {
 192                         compatible = "arm,cci-400-ctrl-if";
 193                         interface-type = "ace-lite";
 194                         reg = <0x1000 0x1000>;
 195                 };
 196
 197                 cci_control1: slave-if@4000 {
 198                         compatible = "arm,cci-400-ctrl-if";
 199                         interface-type = "ace";
 200                         reg = <0x4000 0x1000>;
 201                 };
 202
 203                 cci_control2: slave-if@5000 {
 204                         compatible = "arm,cci-400-ctrl-if";
 205                         interface-type = "ace";
 206                         reg = <0x5000 0x1000>;
 207                 };
 208
 209                 pmu@9000 {
 210                          compatible = "arm,cci-400-pmu";
 211                          reg = <0x9000 0x5000>;
 212                          interrupts = <0 101 4>,
 213                                       <0 102 4>,
 214                                       <0 103 4>,
 215                                       <0 104 4>,
 216                                       <0 105 4>;
 217                 };
 218         };
 219
 220 This CCI node corresponds to a CCI component whose control registers sits
 221 at address 0x000000002c090000.
 222 CCI slave interface @0x000000002c091000 is connected to dma controller dma0.
 223 CCI slave interface @0x000000002c094000 is connected to CPUs {CPU0, CPU1};
 224 CCI slave interface @0x000000002c095000 is connected to CPUs {CPU2, CPU3};