[PATCH v5 2/4] Bring in some other reserved-memory files

[Simon Glass]

Add schema yaml files from v6.5 which are not vendor-specific, nor
Linux-specific.

Signed-off-by: Simon Glass <sjg@xxxxxxxxxxxx>
---

Changes in v5:
- Trim back to just a subset of mostly generic schemas

Changes in v4:
- New patch

 .../schemas/reserved-memory/framebuffer.yaml  | 52 ++++++++++
 .../reserved-memory/memory-region.yaml        | 40 ++++++++
 .../reserved-memory/shared-dma-pool.yaml      | 97 +++++++++++++++++++
 3 files changed, 189 insertions(+)
 create mode 100644 dtschema/schemas/reserved-memory/framebuffer.yaml
 create mode 100644 dtschema/schemas/reserved-memory/memory-region.yaml
 create mode 100644 dtschema/schemas/reserved-memory/shared-dma-pool.yaml

diff --git a/dtschema/schemas/reserved-memory/framebuffer.yaml b/dtschema/schemas/reserved-memory/framebuffer.yaml
new file mode 100644
index 0000000..851ec24
--- /dev/null
+++ b/dtschema/schemas/reserved-memory/framebuffer.yaml
@@ -0,0 +1,52 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/framebuffer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: /reserved-memory framebuffer node
+
+maintainers:
+  - devicetree-spec@xxxxxxxxxxxxxxx
+
+allOf:
+  - $ref: reserved-memory.yaml
+
+properties:
+  compatible:
+    const: framebuffer
+    description: >
+      This indicates a region of memory meant to be used as a framebuffer for
+      a set of display devices. It can be used by an operating system to keep
+      the framebuffer from being overwritten and use it as the backing memory
+      for a display device (such as simple-framebuffer).
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    / {
+        compatible = "foo";
+        model = "foo";
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        chosen {
+            framebuffer {
+                compatible = "simple-framebuffer";
+                memory-region = <&fb>;
+            };
+        };
+
+        reserved-memory {
+            #address-cells = <1>;
+            #size-cells = <1>;
+            ranges;
+
+            fb: framebuffer@80000000 {
+                compatible = "framebuffer";
+                reg = <0x80000000 0x007e9000>;
+            };
+        };
+    };
+...
diff --git a/dtschema/schemas/reserved-memory/memory-region.yaml b/dtschema/schemas/reserved-memory/memory-region.yaml
new file mode 100644
index 0000000..592f180
--- /dev/null
+++ b/dtschema/schemas/reserved-memory/memory-region.yaml
@@ -0,0 +1,40 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/memory-region.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Reserved Memory Region
+
+maintainers:
+  - devicetree-spec@xxxxxxxxxxxxxxx
+
+description: |
+  Regions in the /reserved-memory node may be referenced by other device
+  nodes by adding a memory-region property to the device node.
+
+select: true
+
+properties:
+  memory-region:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    description: >
+      Phandle to a /reserved-memory child node assigned to the device.
+
+  memory-region-names:
+    $ref: /schemas/types.yaml#/definitions/string-array
+    description: >
+      A list of names, one for each corresponding entry in the
+      memory-region property
+
+additionalProperties: true
+
+examples:
+  - |
+    fb0: video@12300000 {
+        /* ... */
+        reg = <0x12300000 0x1000>;
+        memory-region = <&display_reserved>;
+    };
+
+...
diff --git a/dtschema/schemas/reserved-memory/shared-dma-pool.yaml b/dtschema/schemas/reserved-memory/shared-dma-pool.yaml
new file mode 100644
index 0000000..457de09
--- /dev/null
+++ b/dtschema/schemas/reserved-memory/shared-dma-pool.yaml
@@ -0,0 +1,97 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reserved-memory/shared-dma-pool.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: /reserved-memory DMA pool
+
+maintainers:
+  - devicetree-spec@xxxxxxxxxxxxxxx
+
+allOf:
+  - $ref: reserved-memory.yaml
+
+properties:
+  compatible:
+    oneOf:
+      - const: shared-dma-pool
+        description: >
+          This indicates a region of memory meant to be used as a shared
+          pool of DMA buffers for a set of devices. It can be used by an
+          operating system to instantiate the necessary pool management
+          subsystem if necessary.
+
+      - const: restricted-dma-pool
+        description: >
+          This indicates a region of memory meant to be used as a pool
+          of restricted DMA buffers for a set of devices. The memory
+          region would be the only region accessible to those devices.
+          When using this, the no-map and reusable properties must not
+          be set, so the operating system can create a virtual mapping
+          that will be used for synchronization. The main purpose for
+          restricted DMA is to mitigate the lack of DMA access control
+          on systems without an IOMMU, which could result in the DMA
+          accessing the system memory at unexpected times and/or
+          unexpected addresses, possibly leading to data leakage or
+          corruption. The feature on its own provides a basic level of
+          protection against the DMA overwriting buffer contents at
+          unexpected times. However, to protect against general data
+          leakage and system memory corruption, the system needs to
+          provide way to lock down the memory access, e.g., MPU. Note
+          that since coherent allocation needs remapping, one must set
+          up another device coherent pool by shared-dma-pool and use
+          dma_alloc_from_dev_coherent instead for atomic coherent
+          allocation.
+
+  linux,cma-default:
+    type: boolean
+    description: >
+      If this property is present, then Linux will use the region for
+      the default pool of the contiguous memory allocator.
+
+  linux,dma-default:
+    type: boolean
+    description: >
+      If this property is present, then Linux will use the region for
+      the default pool of the consistent DMA allocator.
+
+if:
+  properties:
+    compatible:
+      contains:
+        const: restricted-dma-pool
+then:
+  properties:
+    no-map: false
+    reusable: false
+
+unevaluatedProperties: false
+
+examples:
+  - |
+      reserved-memory {
+          #address-cells = <1>;
+          #size-cells = <1>;
+          ranges;
+
+          /* global autoconfigured region for contiguous allocations */
+          linux,cma {
+              compatible = "shared-dma-pool";
+              reusable;
+              size = <0x4000000>;
+              alignment = <0x2000>;
+              linux,cma-default;
+          };
+
+          display_reserved: framebuffer@78000000 {
+              reg = <0x78000000 0x800000>;
+          };
+
+          restricted_dma_reserved: restricted-dma-pool@50000000 {
+              compatible = "restricted-dma-pool";
+              reg = <0x50000000 0x4000000>;
+          };
+      };
+
+...
-- 
2.42.0.rc2.253.gd59a3bf2b4-goog