new file mode 100644
@@ -0,0 +1,135 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,lpddr2-timings.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: LPDDR2 SDRAM AC timing parameters for a given speed-bin
+
+maintainers:
+ - Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
+
+properties:
+ compatible:
+ const: jedec,lpddr2-timings
+
+ max-freq:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Maximum DDR clock frequency for the speed-bin, in Hz.
+
+ min-freq:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Minimum DDR clock frequency for the speed-bin, in Hz.
+
+ tCKESR:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ CKE minimum pulse width during SELF REFRESH (low pulse width during
+ SELF REFRESH) in pico seconds.
+
+ tDQSCK-max:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ DQS output data access time from CK_t/CK_c in pico seconds.
+
+ tDQSCK-max-derated:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ DQS output data access time from CK_t/CK_c, temperature de-rated, in pico
+ seconds.
+
+ tFAW:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Four-bank activate window in pico seconds.
+
+ tRAS-max-ns:
+ description: |
+ Row active time in nano seconds.
+
+ tRAS-min:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Row active time in pico seconds.
+
+ tRCD:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ RAS-to-CAS delay in pico seconds.
+
+ tRPab:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Row precharge time (all banks) in pico seconds.
+
+ tRRD:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Active bank A to active bank B in pico seconds.
+
+ tRTP:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Internal READ to PRECHARGE command delay in pico seconds.
+
+ tWR:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ WRITE recovery time in pico seconds.
+
+ tWTR:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Internal WRITE-to-READ command delay in pico seconds.
+
+ tXP:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Exit power-down to next valid command delay in pico seconds.
+
+ tZQCL:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ SELF REFRESH exit to next valid command delay in pico seconds.
+
+ tZQCS:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ SELF REFRESH exit to next valid command delay in pico seconds.
+
+ tZQinit:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ SELF REFRESH exit to next valid command delay in pico seconds.
+
+required:
+ - compatible
+ - min-freq
+ - max-freq
+
+additionalProperties: false
+
+examples:
+ - |
+ timings {
+ compatible = "jedec,lpddr2-timings";
+ min-freq = <10000000>;
+ max-freq = <400000000>;
+ tCKESR = <15000>;
+ tDQSCK-max = <5500>;
+ tFAW = <50000>;
+ tRAS-max-ns = <70000>;
+ tRAS-min = <42000>;
+ tRPab = <21000>;
+ tRCD = <18000>;
+ tRRD = <10000>;
+ tRTP = <7500>;
+ tWR = <15000>;
+ tWTR = <7500>;
+ tXP = <7500>;
+ tZQCL = <360000>;
+ tZQCS = <90000>;
+ tZQinit = <1000000>;
+ };
@@ -142,14 +142,12 @@ properties:
patternProperties:
"^lpddr2-timings":
- type: object
+ $ref: jedec,lpddr2-timings.yaml
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".
+ speed-bins as is required.
required:
- compatible
deleted file mode 100644
@@ -1,52 +0,0 @@
-* AC timing parameters of LPDDR2(JESD209-2) memories for a given speed-bin
-
-Required properties:
-- compatible : Should be "jedec,lpddr2-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). Parameters with
-a different unit have a suffix indicating the unit such as 'tRAS-max-ns'
-- tRCD
-- tWR
-- tRAS-min
-- tRRD
-- tWTR
-- tXP
-- tRTP
-- tDQSCK-max
-- tFAW
-- tZQCS
-- tZQinit
-- tRPab
-- tZQCL
-- tCKESR
-- tRAS-max-ns
-- tDQSCK-max-derated
-
-Example:
-
-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>;
-};
Convert the LPDDR2 memory timings bindings to DT schema format. Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> --- .../ddr/jedec,lpddr2-timings.yaml | 135 ++++++++++++++++++ .../memory-controllers/ddr/jedec,lpddr2.yaml | 6 +- .../memory-controllers/ddr/lpddr2-timings.txt | 52 ------- 3 files changed, 137 insertions(+), 56 deletions(-) create mode 100644 Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2-timings.yaml delete mode 100644 Documentation/devicetree/bindings/memory-controllers/ddr/lpddr2-timings.txt