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Diffstat (limited to 'Documentation/devicetree/bindings/ddr/lpddr3.txt')
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diff --git a/Documentation/devicetree/bindings/ddr/lpddr3.txt b/Documentation/devicetree/bindings/ddr/lpddr3.txt new file mode 100644 index 000000000..a0eda35a8 --- /dev/null +++ b/Documentation/devicetree/bindings/ddr/lpddr3.txt @@ -0,0 +1,101 @@ +* LPDDR3 SDRAM memories compliant to JEDEC JESD209-3C + +Required properties: +- compatible : Should be "<vendor>,<type>", and generic value "jedec,lpddr3". + Example "<vendor>,<type>" values: + "samsung,K3QF2F20DB" + +- density : <u32> representing density in Mb (Mega bits) +- io-width : <u32> representing bus width. Possible values are 8, 16, 32, 64 +- #address-cells: Must be set to 1 +- #size-cells: Must be set to 0 + +Optional properties: + +The following optional properties represent the minimum value of some AC +timing parameters of the DDR device in terms of number of clock cycles. +These values shall be obtained from the device data-sheet. +- tRFC-min-tck +- tRRD-min-tck +- tRPab-min-tck +- tRPpb-min-tck +- tRCD-min-tck +- tRC-min-tck +- tRAS-min-tck +- tWTR-min-tck +- tWR-min-tck +- tRTP-min-tck +- tW2W-C2C-min-tck +- tR2R-C2C-min-tck +- tWL-min-tck +- tDQSCK-min-tck +- tRL-min-tck +- tFAW-min-tck +- tXSR-min-tck +- tXP-min-tck +- tCKE-min-tck +- tCKESR-min-tck +- tMRD-min-tck + +Child nodes: +- The lpddr3 node may have one or more child nodes of type "lpddr3-timings". + "lpddr3-timings" provides AC timing parameters of the device for + a given speed-bin. Please see Documentation/devicetree/ + bindings/ddr/lpddr3-timings.txt for more information on "lpddr3-timings" + +Example: + +samsung_K3QF2F20DB: lpddr3 { + compatible = "samsung,K3QF2F20DB", "jedec,lpddr3"; + density = <16384>; + io-width = <32>; + #address-cells = <1>; + #size-cells = <0>; + + tRFC-min-tck = <17>; + tRRD-min-tck = <2>; + tRPab-min-tck = <2>; + tRPpb-min-tck = <2>; + tRCD-min-tck = <3>; + tRC-min-tck = <6>; + tRAS-min-tck = <5>; + tWTR-min-tck = <2>; + tWR-min-tck = <7>; + tRTP-min-tck = <2>; + tW2W-C2C-min-tck = <0>; + tR2R-C2C-min-tck = <0>; + tWL-min-tck = <8>; + tDQSCK-min-tck = <5>; + tRL-min-tck = <14>; + tFAW-min-tck = <5>; + tXSR-min-tck = <12>; + tXP-min-tck = <2>; + tCKE-min-tck = <2>; + tCKESR-min-tck = <2>; + tMRD-min-tck = <5>; + + timings_samsung_K3QF2F20DB_800mhz: lpddr3-timings@800000000 { + compatible = "jedec,lpddr3-timings"; + /* workaround: 'reg' shows max-freq */ + reg = <800000000>; + min-freq = <100000000>; + tRFC = <65000>; + tRRD = <6000>; + tRPab = <12000>; + tRPpb = <12000>; + tRCD = <10000>; + tRC = <33750>; + tRAS = <23000>; + tWTR = <3750>; + tWR = <7500>; + tRTP = <3750>; + tW2W-C2C = <0>; + tR2R-C2C = <0>; + tFAW = <25000>; + tXSR = <70000>; + tXP = <3750>; + tCKE = <3750>; + tCKESR = <3750>; + tMRD = <7000>; + }; +} |