Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml

   1 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
   2 %YAML 1.2
   3 ---
   4 $id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,lpddr2.yaml#
   5 $schema: http://devicetree.org/meta-schemas/core.yaml#
   6
   7 title: LPDDR2 SDRAM compliant to JEDEC JESD209-2
   8
   9 maintainers:
  10   - Krzysztof Kozlowski <krzk@kernel.org>
  11
  12 allOf:
  13   - $ref: jedec,lpddr-props.yaml#
  14
  15 properties:
  16   compatible:
  17     oneOf:
  18       - items:
  19           - enum:
  20               - elpida,ECB240ABACN
  21               - elpida,B8132B2PB-6D-F
  22           - enum:
  23               - jedec,lpddr2-nvm
  24               - jedec,lpddr2-s2
  25               - jedec,lpddr2-s4
  26       - items:
  27           - pattern: "^lpddr2-[0-9a-f]{2},[0-9a-f]{4}$"
  28           - enum:
  29               - jedec,lpddr2-nvm
  30               - jedec,lpddr2-s2
  31               - jedec,lpddr2-s4
  32
  33   revision-id1:
  34     $ref: /schemas/types.yaml#/definitions/uint32
  35     maximum: 255
  36     description: |
  37       Revision 1 value of SDRAM chip. Obtained from device datasheet.
  38       Property is deprecated, use revision-id instead.
  39     deprecated: true
  40
  41   revision-id2:
  42     $ref: /schemas/types.yaml#/definitions/uint32
  43     maximum: 255
  44     description: |
  45       Revision 2 value of SDRAM chip. Obtained from device datasheet.
  46       Property is deprecated, use revision-id instead.
  47     deprecated: true
  48
  49   tRRD-min-tck:
  50     $ref: /schemas/types.yaml#/definitions/uint32
  51     maximum: 16
  52     description: |
  53       Active bank a to active bank b in terms of number of clock cycles.
  54       Obtained from device datasheet.
  55
  56   tWTR-min-tck:
  57     $ref: /schemas/types.yaml#/definitions/uint32
  58     maximum: 16
  59     description: |
  60       Internal WRITE-to-READ command delay in terms of number of clock cycles.
  61       Obtained from device datasheet.
  62
  63   tXP-min-tck:
  64     $ref: /schemas/types.yaml#/definitions/uint32
  65     maximum: 16
  66     description: |
  67       Exit power-down to next valid command delay in terms of number of clock
  68       cycles. Obtained from device datasheet.
  69
  70   tRTP-min-tck:
  71     $ref: /schemas/types.yaml#/definitions/uint32
  72     maximum: 16
  73     description: |
  74       Internal READ to PRECHARGE command delay in terms of number of clock
  75       cycles. Obtained from device datasheet.
  76
  77   tCKE-min-tck:
  78     $ref: /schemas/types.yaml#/definitions/uint32
  79     maximum: 16
  80     description: |
  81       CKE minimum pulse width (HIGH and LOW pulse width) in terms of number
  82       of clock cycles. Obtained from device datasheet.
  83
  84   tRPab-min-tck:
  85     $ref: /schemas/types.yaml#/definitions/uint32
  86     maximum: 16
  87     description: |
  88       Row precharge time (all banks) in terms of number of clock cycles.
  89       Obtained from device datasheet.
  90
  91   tRCD-min-tck:
  92     $ref: /schemas/types.yaml#/definitions/uint32
  93     maximum: 16
  94     description: |
  95       RAS-to-CAS delay in terms of number of clock cycles. Obtained from
  96       device datasheet.
  97
  98   tWR-min-tck:
  99     $ref: /schemas/types.yaml#/definitions/uint32
 100     maximum: 16
 101     description: |
 102       WRITE recovery time in terms of number of clock cycles. Obtained from
 103       device datasheet.
 104
 105   tRASmin-min-tck:
 106     $ref: /schemas/types.yaml#/definitions/uint32
 107     maximum: 16
 108     description: |
 109       Row active time in terms of number of clock cycles. Obtained from device
 110       datasheet.
 111
 112   tCKESR-min-tck:
 113     $ref: /schemas/types.yaml#/definitions/uint32
 114     maximum: 16
 115     description: |
 116       CKE minimum pulse width during SELF REFRESH (low pulse width during
 117       SELF REFRESH) in terms of number of clock cycles. Obtained from device
 118       datasheet.
 119
 120   tFAW-min-tck:
 121     $ref: /schemas/types.yaml#/definitions/uint32
 122     maximum: 16
 123     description: |
 124       Four-bank activate window in terms of number of clock cycles. Obtained
 125       from device datasheet.
 126
 127 patternProperties:
 128   "^lpddr2-timings":
 129     $ref: jedec,lpddr2-timings.yaml
 130     description: |
 131       The lpddr2 node may have one or more child nodes of type "lpddr2-timings".
 132       "lpddr2-timings" provides AC timing parameters of the device for
 133       a given speed-bin. The user may provide the timings for as many
 134       speed-bins as is required.
 135
 136 required:
 137   - compatible
 138   - density
 139   - io-width
 140
 141 unevaluatedProperties: false
 142
 143 examples:
 144   - |
 145     elpida_ECB240ABACN: lpddr2 {
 146         compatible = "elpida,ECB240ABACN", "jedec,lpddr2-s4";
 147         density = <2048>;
 148         io-width = <32>;
 149         revision-id = <1 0>;
 150
 151         tRPab-min-tck = <3>;
 152         tRCD-min-tck = <3>;
 153         tWR-min-tck = <3>;
 154         tRASmin-min-tck = <3>;
 155         tRRD-min-tck = <2>;
 156         tWTR-min-tck = <2>;
 157         tXP-min-tck = <2>;
 158         tRTP-min-tck = <2>;
 159         tCKE-min-tck = <3>;
 160         tCKESR-min-tck = <3>;
 161         tFAW-min-tck = <8>;
 162
 163         timings_elpida_ECB240ABACN_400mhz: lpddr2-timings0 {
 164             compatible = "jedec,lpddr2-timings";
 165             min-freq = <10000000>;
 166             max-freq = <400000000>;
 167             tRPab = <21000>;
 168             tRCD = <18000>;
 169             tWR = <15000>;
 170             tRAS-min = <42000>;
 171             tRRD = <10000>;
 172             tWTR = <7500>;
 173             tXP = <7500>;
 174             tRTP = <7500>;
 175             tCKESR = <15000>;
 176             tDQSCK-max = <5500>;
 177             tFAW = <50000>;
 178             tZQCS = <90000>;
 179             tZQCL = <360000>;
 180             tZQinit = <1000000>;
 181             tRAS-max-ns = <70000>;
 182         };
 183
 184         timings_elpida_ECB240ABACN_200mhz: lpddr2-timings1 {
 185             compatible = "jedec,lpddr2-timings";
 186             min-freq = <10000000>;
 187             max-freq = <200000000>;
 188             tRPab = <21000>;
 189             tRCD = <18000>;
 190             tWR = <15000>;
 191             tRAS-min = <42000>;
 192             tRRD = <10000>;
 193             tWTR = <10000>;
 194             tXP = <7500>;
 195             tRTP = <7500>;
 196             tCKESR = <15000>;
 197             tDQSCK-max = <5500>;
 198             tFAW = <50000>;
 199             tZQCS = <90000>;
 200             tZQCL = <360000>;
 201             tZQinit = <1000000>;
 202             tRAS-max-ns = <70000>;
 203         };
 204     };