[PATCH v3 2/8] dt-bindings: memory: lpddr3-timings: convert to dtschema

Krzysztof Kozlowski krzysztof.kozlowski at canonical.com
Sun Feb 6 05:58:01 PST 2022


Convert the LPDDR3 memory timings bindings to DT schema format.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski at canonical.com>
Reviewed-by: Dmitry Osipenko <digetx at gmail.com>
---
 .../ddr/jedec,lpddr3-timings.yaml             | 153 ++++++++++++++++++
 .../memory-controllers/ddr/lpddr3-timings.txt |  58 -------
 2 files changed, 153 insertions(+), 58 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr3-timings.yaml
 delete mode 100644 Documentation/devicetree/bindings/memory-controllers/ddr/lpddr3-timings.txt

diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr3-timings.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr3-timings.yaml
new file mode 100644
index 000000000000..98bc219e8a25
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr3-timings.yaml
@@ -0,0 +1,153 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,lpddr3-timings.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: LPDDR3 SDRAM AC timing parameters for a given speed-bin
+
+maintainers:
+  - Krzysztof Kozlowski <krzysztof.kozlowski at canonical.com>
+
+properties:
+  compatible:
+    const: jedec,lpddr3-timings
+
+  reg:
+    maxItems: 1
+    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.
+
+  tCKE:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      CKE minimum pulse width (HIGH and LOW pulse width) in pico seconds.
+
+  tCKESR:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      CKE minimum pulse width during SELF REFRESH (low pulse width during
+      SELF REFRESH) in pico seconds.
+
+  tFAW:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      Four-bank activate window in pico seconds.
+
+  tMRD:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      Mode register set command delay in pico seconds.
+
+  tR2R-C2C:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      Additional READ-to-READ delay in chip-to-chip cases in pico seconds.
+
+  tRAS:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      Row active time in pico seconds.
+
+  tRC:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      ACTIVATE-to-ACTIVATE command period in pico seconds.
+
+  tRCD:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      RAS-to-CAS delay in pico seconds.
+
+  tRFC:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      Refresh Cycle time in pico seconds.
+
+  tRPab:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      Row precharge time (all banks) in pico seconds.
+
+  tRPpb:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      Row precharge time (single 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.
+
+  tW2W-C2C:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      Additional WRITE-to-WRITE delay in chip-to-chip cases 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.
+
+  tXSR:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      SELF REFRESH exit to next valid command delay in pico seconds.
+
+required:
+  - compatible
+  - min-freq
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    lpddr3 {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        timings at 800000000 {
+            compatible = "jedec,lpddr3-timings";
+            reg = <800000000>;
+            min-freq = <100000000>;
+            tCKE = <3750>;
+            tCKESR = <3750>;
+            tFAW = <25000>;
+            tMRD = <7000>;
+            tR2R-C2C = <0>;
+            tRAS = <23000>;
+            tRC = <33750>;
+            tRCD = <10000>;
+            tRFC = <65000>;
+            tRPab = <12000>;
+            tRPpb = <12000>;
+            tRRD = <6000>;
+            tRTP = <3750>;
+            tW2W-C2C = <0>;
+            tWR = <7500>;
+            tWTR = <3750>;
+            tXP = <3750>;
+            tXSR = <70000>;
+        };
+    };
diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/lpddr3-timings.txt b/Documentation/devicetree/bindings/memory-controllers/ddr/lpddr3-timings.txt
deleted file mode 100644
index 84705e50a3fd..000000000000
--- a/Documentation/devicetree/bindings/memory-controllers/ddr/lpddr3-timings.txt
+++ /dev/null
@@ -1,58 +0,0 @@
-* 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>
-- reg : 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 at 800000000 {
-	compatible	= "jedec,lpddr3-timings";
-	reg		= <800000000>; /* workaround: it shows max-freq */
-	min-freq	= <100000000>;
-	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>;
-};
-- 
2.32.0




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