dt-bindings: Add devicetree bindings

Add snapshot of device tree bindings from keystone common kernel, branch
"android-mainline-keystone-qcom-release" at c4c12103f9c0 ("Snap for 9228065
from e32903b9a63bb558df8b803b076619c53c16baad to
android-mainline-keystone-qcom-release").

Change-Id: I7682079615cbd9f29340a5c1f2a1d84ec441a1f1
Signed-off-by: Melody Olvera <quic_molvera@quicinc.com>

bindings/memory-controllers/ddr/jedec,lpddr-props.yaml

@@ -0,0 +1,74 @@
+# 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