Documentation/devicetree/bindings/ddr/lpddr3.txt

   1 * LPDDR3 SDRAM memories compliant to JEDEC JESD209-3C
   2
   3 Required properties:
   4 - compatible : Should be "<vendor>,<type>", and generic value "jedec,lpddr3".
   5   Example "<vendor>,<type>" values:
   6     "samsung,K3QF2F20DB"
   7
   8 - density  : <u32> representing density in Mb (Mega bits)
   9 - io-width : <u32> representing bus width. Possible values are 8, 16, 32, 64
  10 - #address-cells: Must be set to 1
  11 - #size-cells: Must be set to 0
  12
  13 Optional properties:
  14
  15 The following optional properties represent the minimum value of some AC
  16 timing parameters of the DDR device in terms of number of clock cycles.
  17 These values shall be obtained from the device data-sheet.
  18 - tRFC-min-tck
  19 - tRRD-min-tck
  20 - tRPab-min-tck
  21 - tRPpb-min-tck
  22 - tRCD-min-tck
  23 - tRC-min-tck
  24 - tRAS-min-tck
  25 - tWTR-min-tck
  26 - tWR-min-tck
  27 - tRTP-min-tck
  28 - tW2W-C2C-min-tck
  29 - tR2R-C2C-min-tck
  30 - tWL-min-tck
  31 - tDQSCK-min-tck
  32 - tRL-min-tck
  33 - tFAW-min-tck
  34 - tXSR-min-tck
  35 - tXP-min-tck
  36 - tCKE-min-tck
  37 - tCKESR-min-tck
  38 - tMRD-min-tck
  39
  40 Child nodes:
  41 - The lpddr3 node may have one or more child nodes of type "lpddr3-timings".
  42   "lpddr3-timings" provides AC timing parameters of the device for
  43   a given speed-bin. Please see Documentation/devicetree/
  44   bindings/ddr/lpddr3-timings.txt for more information on "lpddr3-timings"
  45
  46 Example:
  47
  48 samsung_K3QF2F20DB: lpddr3 {
  49         compatible      = "samsung,K3QF2F20DB", "jedec,lpddr3";
  50         density         = <16384>;
  51         io-width        = <32>;
  52         #address-cells  = <1>;
  53         #size-cells     = <0>;
  54
  55         tRFC-min-tck            = <17>;
  56         tRRD-min-tck            = <2>;
  57         tRPab-min-tck           = <2>;
  58         tRPpb-min-tck           = <2>;
  59         tRCD-min-tck            = <3>;
  60         tRC-min-tck             = <6>;
  61         tRAS-min-tck            = <5>;
  62         tWTR-min-tck            = <2>;
  63         tWR-min-tck             = <7>;
  64         tRTP-min-tck            = <2>;
  65         tW2W-C2C-min-tck        = <0>;
  66         tR2R-C2C-min-tck        = <0>;
  67         tWL-min-tck             = <8>;
  68         tDQSCK-min-tck          = <5>;
  69         tRL-min-tck             = <14>;
  70         tFAW-min-tck            = <5>;
  71         tXSR-min-tck            = <12>;
  72         tXP-min-tck             = <2>;
  73         tCKE-min-tck            = <2>;
  74         tCKESR-min-tck          = <2>;
  75         tMRD-min-tck            = <5>;
  76
  77         timings_samsung_K3QF2F20DB_800mhz: lpddr3-timings@800000000 {
  78                 compatible      = "jedec,lpddr3-timings";
  79                 /* workaround: 'reg' shows max-freq */
  80                 reg             = <800000000>;
  81                 min-freq        = <100000000>;
  82                 tRFC            = <65000>;
  83                 tRRD            = <6000>;
  84                 tRPab           = <12000>;
  85                 tRPpb           = <12000>;
  86                 tRCD            = <10000>;
  87                 tRC             = <33750>;
  88                 tRAS            = <23000>;
  89                 tWTR            = <3750>;
  90                 tWR             = <7500>;
  91                 tRTP            = <3750>;
  92                 tW2W-C2C        = <0>;
  93                 tR2R-C2C        = <0>;
  94                 tFAW            = <25000>;
  95                 tXSR            = <70000>;
  96                 tXP             = <3750>;
  97                 tCKE            = <3750>;
  98                 tCKESR          = <3750>;
  99                 tMRD            = <7000>;
 100         };
 101 }