| * LPDDR2 SDRAM memories compliant to JEDEC JESD209-2 |
| |
| Required properties: |
| - compatible : Should be one of - "jedec,lpddr2-nvm", "jedec,lpddr2-s2", |
| "jedec,lpddr2-s4" |
| |
| "ti,jedec-lpddr2-s2" should be listed if the memory part is LPDDR2-S2 type |
| |
| "ti,jedec-lpddr2-s4" should be listed if the memory part is LPDDR2-S4 type |
| |
| "ti,jedec-lpddr2-nvm" should be listed if the memory part is LPDDR2-NVM type |
| |
| - density : <u32> representing density in Mb (Mega bits) |
| |
| - io-width : <u32> representing bus width. Possible values are 8, 16, and 32 |
| |
| 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. |
| - tRRD-min-tck |
| - tWTR-min-tck |
| - tXP-min-tck |
| - tRTP-min-tck |
| - tCKE-min-tck |
| - tRPab-min-tck |
| - tRCD-min-tck |
| - tWR-min-tck |
| - tRASmin-min-tck |
| - tCKESR-min-tck |
| - tFAW-min-tck |
| |
| Child nodes: |
| - The lpddr2 node may have one or more child nodes of type "lpddr2-timings". |
| "lpddr2-timings" provides AC timing parameters of the device for |
| a given speed-bin. The user may provide the timings for as many |
| speed-bins as is required. Please see Documentation/devicetree/ |
| bindings/lpddr2/lpddr2-timings.txt for more information on "lpddr2-timings" |
| |
| Example: |
| |
| elpida_ECB240ABACN : lpddr2 { |
| compatible = "Elpida,ECB240ABACN","jedec,lpddr2-s4"; |
| density = <2048>; |
| io-width = <32>; |
| |
| tRPab-min-tck = <3>; |
| tRCD-min-tck = <3>; |
| tWR-min-tck = <3>; |
| tRASmin-min-tck = <3>; |
| tRRD-min-tck = <2>; |
| tWTR-min-tck = <2>; |
| tXP-min-tck = <2>; |
| tRTP-min-tck = <2>; |
| tCKE-min-tck = <3>; |
| tCKESR-min-tck = <3>; |
| tFAW-min-tck = <8>; |
| |
| timings_elpida_ECB240ABACN_400mhz: lpddr2-timings@0 { |
| compatible = "jedec,lpddr2-timings"; |
| min-freq = <10000000>; |
| max-freq = <400000000>; |
| tRPab = <21000>; |
| tRCD = <18000>; |
| tWR = <15000>; |
| tRAS-min = <42000>; |
| tRRD = <10000>; |
| tWTR = <7500>; |
| tXP = <7500>; |
| tRTP = <7500>; |
| tCKESR = <15000>; |
| tDQSCK-max = <5500>; |
| tFAW = <50000>; |
| tZQCS = <90000>; |
| tZQCL = <360000>; |
| tZQinit = <1000000>; |
| tRAS-max-ns = <70000>; |
| }; |
| |
| timings_elpida_ECB240ABACN_200mhz: lpddr2-timings@1 { |
| compatible = "jedec,lpddr2-timings"; |
| min-freq = <10000000>; |
| max-freq = <200000000>; |
| tRPab = <21000>; |
| tRCD = <18000>; |
| tWR = <15000>; |
| tRAS-min = <42000>; |
| tRRD = <10000>; |
| tWTR = <10000>; |
| tXP = <7500>; |
| tRTP = <7500>; |
| tCKESR = <15000>; |
| tDQSCK-max = <5500>; |
| tFAW = <50000>; |
| tZQCS = <90000>; |
| tZQCL = <360000>; |
| tZQinit = <1000000>; |
| tRAS-max-ns = <70000>; |
| }; |
| |
| } |