summaryrefslogtreecommitdiffstats
path: root/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml')
-rw-r--r--Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml223
1 files changed, 223 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
new file mode 100644
index 000000000000..25ed0266f6dd
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
@@ -0,0 +1,223 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,lpddr2.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: LPDDR2 SDRAM compliant to JEDEC JESD209-2
+
+maintainers:
+ - Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
+
+properties:
+ compatible:
+ oneOf:
+ - items:
+ - enum:
+ - elpida,ECB240ABACN
+ - elpida,B8132B2PB-6D-F
+ - enum:
+ - jedec,lpddr2-s4
+ - items:
+ - enum:
+ - jedec,lpddr2-s2
+ - items:
+ - enum:
+ - jedec,lpddr2-nvm
+
+ revision-id1:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ maximum: 255
+ description: |
+ Revision 1 value of SDRAM chip. Obtained from device datasheet.
+
+ revision-id2:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ maximum: 255
+ description: |
+ Revision 2 value of SDRAM chip. Obtained from device datasheet.
+
+ density:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Density in megabits of SDRAM chip. Obtained from device datasheet.
+ enum:
+ - 64
+ - 128
+ - 256
+ - 512
+ - 1024
+ - 2048
+ - 4096
+ - 8192
+ - 16384
+ - 32768
+
+ io-width:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ IO bus width in bits of SDRAM chip. Obtained from device datasheet.
+ enum:
+ - 32
+ - 16
+ - 8
+
+ tRRD-min-tck:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ maximum: 16
+ description: |
+ Active bank a to active bank b in terms of number of clock cycles.
+ Obtained from device datasheet.
+
+ tWTR-min-tck:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ maximum: 16
+ description: |
+ Internal WRITE-to-READ command delay in terms of number of clock cycles.
+ Obtained from device datasheet.
+
+ tXP-min-tck:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ maximum: 16
+ description: |
+ Exit power-down to next valid command delay in terms of number of clock
+ cycles. Obtained from device datasheet.
+
+ tRTP-min-tck:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ maximum: 16
+ description: |
+ Internal READ to PRECHARGE command delay in terms of number of clock
+ cycles. Obtained from device datasheet.
+
+ tCKE-min-tck:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ maximum: 16
+ description: |
+ CKE minimum pulse width (HIGH and LOW pulse width) in terms of number
+ of clock cycles. Obtained from device datasheet.
+
+ tRPab-min-tck:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ maximum: 16
+ description: |
+ Row precharge time (all banks) in terms of number of clock cycles.
+ Obtained from device datasheet.
+
+ tRCD-min-tck:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ maximum: 16
+ description: |
+ RAS-to-CAS delay in terms of number of clock cycles. Obtained from
+ device datasheet.
+
+ tWR-min-tck:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ maximum: 16
+ description: |
+ WRITE recovery time in terms of number of clock cycles. Obtained from
+ device datasheet.
+
+ tRASmin-min-tck:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ maximum: 16
+ description: |
+ Row active time in terms of number of clock cycles. Obtained from device
+ datasheet.
+
+ tCKESR-min-tck:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ maximum: 16
+ description: |
+ CKE minimum pulse width during SELF REFRESH (low pulse width during
+ SELF REFRESH) in terms of number of clock cycles. Obtained from device
+ datasheet.
+
+ tFAW-min-tck:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ maximum: 16
+ description: |
+ Four-bank activate window in terms of number of clock cycles. Obtained
+ from device datasheet.
+
+patternProperties:
+ "^lpddr2-timings":
+ type: object
+ description: |
+ 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/memory-controllers/ddr/lpddr2-timings.txt for more information
+ on "lpddr2-timings".
+
+required:
+ - compatible
+ - density
+ - io-width
+
+additionalProperties: false
+
+examples:
+ - |
+ elpida_ECB240ABACN: lpddr2 {
+ compatible = "elpida,ECB240ABACN", "jedec,lpddr2-s4";
+ density = <2048>;
+ io-width = <32>;
+ revision-id1 = <1>;
+ revision-id2 = <0>;
+
+ 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-timings0 {
+ 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-timings1 {
+ 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>;
+ };
+ };