dt-bindings: memory: factorise LPDDR props into SDRAM props

LPDDR and DDR bindings are SDRAM types and are likely to share the same
properties (at least for density, io-width and reg).
To avoid bindings duplication, factorise the properties.

The compatible description has been updated because the MR (Mode
registers) used to get manufacturer ID and revision ID are not present
in case of DDR.
Those information should be in a SPD (Serial Presence Detect) EEPROM in
case of DIMM module or are known in case of soldered memory chips as
they are in the datasheet of the memory chips.

Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Clément Le Goffic <legoffic.clement@gmail.com>
Link: https://patch.msgid.link/20251118-b4-ddr-bindings-v9-1-a033ac5144da@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr-props.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr-props.yaml
deleted file mode 100644 (file)
index 30267ce..0000000
--- a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr-props.yaml
+++ /dev/null
@@ -1,74 +0,0 @@
-# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
-%YAML 1.2
----
-$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,lpddr-props.yaml#
-$schema: http://devicetree.org/meta-schemas/core.yaml#
-
-title: Common properties for LPDDR types
-
-description:
-  Different LPDDR types generally use the same properties and only differ in the
-  range of legal values for each. This file defines the common parts that can be
-  reused for each type. Nodes using this schema should generally be nested under
-  an LPDDR channel node.
-
-maintainers:
-  - Krzysztof Kozlowski <krzk@kernel.org>
-
-properties:
-  compatible:
-    description:
-      Compatible strings can be either explicit vendor names and part numbers
-      (e.g. elpida,ECB240ABACN), or generated strings of the form
-      lpddrX-YY,ZZZZ where X is the LPDDR version, YY is the manufacturer ID
-      (from MR5) and ZZZZ is the revision ID (from MR6 and MR7). Both IDs are
-      formatted in lower case hexadecimal representation with leading zeroes.
-      The latter form can be useful when LPDDR nodes are created at runtime by
-      boot firmware that doesn't have access to static part number information.
-
-  reg:
-    description:
-      The rank number of this LPDDR rank when used as a subnode to an LPDDR
-      channel.
-    minimum: 0
-    maximum: 3
-
-  revision-id:
-    $ref: /schemas/types.yaml#/definitions/uint32-array
-    description:
-      Revision IDs read from Mode Register 6 and 7. One byte per uint32 cell (i.e. <MR6 MR7>).
-    maxItems: 2
-    items:
-      minimum: 0
-      maximum: 255
-
-  density:
-    $ref: /schemas/types.yaml#/definitions/uint32
-    description:
-      Density in megabits of SDRAM chip. Decoded from Mode Register 8.
-    enum:
-      - 64
-      - 128
-      - 256
-      - 512
-      - 1024
-      - 2048
-      - 3072
-      - 4096
-      - 6144
-      - 8192
-      - 12288
-      - 16384
-      - 24576
-      - 32768
-
-  io-width:
-    $ref: /schemas/types.yaml#/definitions/uint32
-    description:
-      IO bus width in bits of SDRAM chip. Decoded from Mode Register 8.
-    enum:
-      - 8
-      - 16
-      - 32
-
-additionalProperties: true

diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
index a237bc259273bf15d30569ac8b5c840cae0d5946..704bbc562528efeb572cf9902fd3c48971c6b161 100644 (file)
--- a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
+++ b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr2.yaml
@@ -10,7 +10,7 @@ maintainers:
   - Krzysztof Kozlowski <krzk@kernel.org>
 
 allOf:
-  - $ref: jedec,lpddr-props.yaml#
+  - $ref: jedec,sdram-props.yaml#
 
 properties:
   compatible:

diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr3.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr3.yaml
index e328a1195ba64680d2adf0fa24eb46209b3a3c27..0d28df3d2bfae74b1f0f7b2d58d7e861647cc133 100644 (file)
--- a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr3.yaml
+++ b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr3.yaml
@@ -10,7 +10,7 @@ maintainers:
   - Krzysztof Kozlowski <krzk@kernel.org>
 
 allOf:
-  - $ref: jedec,lpddr-props.yaml#
+  - $ref: jedec,sdram-props.yaml#
 
 properties:
   compatible:

diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr4.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr4.yaml
index a078892fecee36d12a2f4174b4a52e8c54fae970..65aa07861453f0ae720f223be873498dda73d46f 100644 (file)
--- a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr4.yaml
+++ b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr4.yaml
@@ -10,7 +10,7 @@ maintainers:
   - Krzysztof Kozlowski <krzk@kernel.org>
 
 allOf:
-  - $ref: jedec,lpddr-props.yaml#
+  - $ref: jedec,sdram-props.yaml#
 
 properties:
   compatible:

diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr5.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr5.yaml
index e441dac5f154451886258ce6e25e069715c55290..cf5d5a8e94b344d1aceb1a540b1e80c439f99e35 100644 (file)
--- a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr5.yaml
+++ b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr5.yaml
@@ -10,7 +10,7 @@ maintainers:
   - Krzysztof Kozlowski <krzk@kernel.org>
 
 allOf:
-  - $ref: jedec,lpddr-props.yaml#
+  - $ref: jedec,sdram-props.yaml#
 
 properties:
   compatible:

diff --git a/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,sdram-props.yaml b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,sdram-props.yaml
new file mode 100644 (file)
index 0000000..fedd66e
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,sdram-props.yaml
@@ -0,0 +1,94 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,sdram-props.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Common properties for SDRAM types
+
+description:
+  Different SDRAM types generally use the same properties and only differ in the
+  range of legal values for each. This file defines the common parts that can be
+  reused for each type. Nodes using this schema should generally be nested under
+  a SDRAM channel node.
+
+maintainers:
+  - Krzysztof Kozlowski <krzk@kernel.org>
+
+properties:
+  compatible:
+    description: |
+      Compatible strings can be either explicit vendor names and part numbers
+      (e.g. elpida,ECB240ABACN), or generated strings of the form
+      lpddrX-YY,ZZZZ or ddrX-YYYY,AAAA...-ZZ where X, Y, and Z are lowercase
+      hexadecimal with leading zeroes, and A is lowercase ASCII.
+      For LPDDR and DDR SDRAM, X is the SDRAM version (2, 3, 4, etc.).
+      For LPDDR SDRAM:
+        - YY is the manufacturer ID (from MR5), 1 byte
+        - ZZZZ is the revision ID (from MR6 and MR7), 2 bytes
+      For DDR4 SDRAM with SPD, according to JEDEC SPD4.1.2.L-6:
+        - YYYY is the manufacturer ID, 2 bytes, from bytes 320 and 321
+        - AAAA... is the part number, 20 bytes (20 chars) from bytes 329 to 348
+          without trailing spaces
+        - ZZ is the revision ID, 1 byte, from byte 349
+      The former form is useful when the SDRAM vendor and part number are
+      known, for example, when memory is soldered on the board. The latter
+      form is useful when SDRAM nodes are created at runtime by boot firmware
+      that doesn't have access to static part number information.
+
+  reg:
+    description:
+      The rank number of this memory rank when used as a subnode to an memory
+      channel.
+    minimum: 0
+    maximum: 3
+
+  revision-id:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    description: |
+      SDRAM revision ID:
+        - LPDDR SDRAM, decoded from Mode Registers 6 and 7, always 2 bytes.
+        - DDR4 SDRAM, decoded from the SPD from byte 349 according to
+          JEDEC SPD4.1.2.L-6, always 1 byte.
+      One byte per uint32 cell (e.g., <MR6 MR7>).
+    maxItems: 2
+    items:
+      minimum: 0
+      maximum: 255
+
+  density:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      Density of the SDRAM chip in megabits:
+        - LPDDR SDRAM, decoded from Mode Register 8.
+        - DDR4 SDRAM, decoded from the SPD from bits 3-0 of byte 4 according to
+          JEDEC SPD4.1.2.L-6.
+    enum:
+      - 64
+      - 128
+      - 256
+      - 512
+      - 1024
+      - 2048
+      - 3072
+      - 4096
+      - 6144
+      - 8192
+      - 12288
+      - 16384
+      - 24576
+      - 32768
+
+  io-width:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      I/O bus width in bits of the SDRAM chip:
+        - LPDDR SDRAM, decoded from Mode Register 8.
+        - DDR4 SDRAM, decoded from the SPD from bits 2-0 of byte 12 according to
+          JEDEC SPD4.1.2.L-6.
+    enum:
+      - 8
+      - 16
+      - 32
+
+additionalProperties: true