The device tree bindings for LPDDR3 SDRAM memories. For specifying the AC timing parameters of the memory device the 'lpddr3' binding uses binding 'lpddr2-timings'. Signed-off-by: Lukasz Luba <l.luba@xxxxxxxxxxxxxxxxxxx> --- .../devicetree/bindings/lpddr3/lpddr3-timings.txt | 57 +++++++++++++ .../devicetree/bindings/lpddr3/lpddr3.txt | 93 ++++++++++++++++++++++ 2 files changed, 150 insertions(+) create mode 100644 Documentation/devicetree/bindings/lpddr3/lpddr3-timings.txt create mode 100644 Documentation/devicetree/bindings/lpddr3/lpddr3.txt diff --git a/Documentation/devicetree/bindings/lpddr3/lpddr3-timings.txt b/Documentation/devicetree/bindings/lpddr3/lpddr3-timings.txt new file mode 100644 index 0000000..ebf3e00 --- /dev/null +++ b/Documentation/devicetree/bindings/lpddr3/lpddr3-timings.txt @@ -0,0 +1,57 @@ +* AC timing parameters of LPDDR3 memories for a given speed-bin. +* The structures are based on LPDDR2 and extended where needed. + +Required properties: +- compatible : Should be "jedec,lpddr3-timings" +- min-freq : minimum DDR clock frequency for the speed-bin. Type is <u32> +- max-freq : maximum DDR clock frequency for the speed-bin. Type is <u32> + +Optional properties: + +The following properties represent AC timing parameters from the memory +data-sheet of the device for a given speed-bin. All these properties are +of type <u32> and the default unit is ps (pico seconds). +- tRFC +- tRRD +- tRPab +- tRPpb +- tRCD +- tRC +- tRAS +- tWTR +- tWR +- tRTP +- tW2W-C2C +- tR2R-C2C +- tFAW +- tXSR +- tXP +- tCKE +- tCKESR +- tMRD + +Example: + +timings_samsung_K3QF2F20DB_800mhz: lpddr3-timings@0 { + compatible = "jedec,lpddr3-timings"; + min-freq = <100000000>; + max-freq = <800000000>; + 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>; +}; diff --git a/Documentation/devicetree/bindings/lpddr3/lpddr3.txt b/Documentation/devicetree/bindings/lpddr3/lpddr3.txt new file mode 100644 index 0000000..fc7875c --- /dev/null +++ b/Documentation/devicetree/bindings/lpddr3/lpddr3.txt @@ -0,0 +1,93 @@ +* LPDDR3 SDRAM memories compliant to JEDEC JESD209-2 + +Required properties: +- compatible : Should be - "jedec,lpddr3" +- density : <u32> representing density in Mb (Mega bits) +- io-width : <u32> representing bus width. Possible values are 8, 16, 32, 64 + +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/lpddr3/lpddr3-timings.txt for more information on "lpddr3-timings" + +Example: + +samsung_K3QF2F20DB: lpddr3 { + compatible = "Samsung,K3QF2F20DB","jedec,lpddr3"; + density = <16384>; + io-width = <32>; + + 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@0 { + compatible = "jedec,lpddr3-timings"; + min-freq = <100000000>; + max-freq = <800000000>; + 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>; + }; +} -- 2.7.4