[PATCH 4/9] dt-bindings: mmc: add binding for BST DWCMSHC SDHCI controller

[Albert Yang <yangzh0906@thundersoft.com>]

Add device tree binding documentation for the Black Sesame Technologies
(BST) DWCMSHC SDHCI controller.

This binding describes the required and optional properties for the
bst,c1200-dwcmshc-sdhci compatible controller, including register layout,
interrupts, bus width, clock configuration, and other controller-specific
features.

Signed-off-by: Albert Yang <yangzh0906@thundersoft.com>

---
Changes for v4:
- Remove Signed-off-by line for Ge Gordon
- Change `$ref: mmc-controller.yaml#` to `$ref: sdhci-common.yaml#`
- Change compatible string from `bst,c1200-dwcmshc-sdhci` to `bst,c1200-sdhci`

Changes for v3:
- Switch reg schema from maxItems to explicit items with per-entry descriptions
- Improve example: add irq.h include and wrap under a bus node with address/size cells
- Drop status = "disabled" from example; keep example concise
- Add Signed-off-by: Ge Gordon

Changes for v2:
- Simplify description, remove redundant paragraphs
- Update $schema to reference mmc-specific scheme
- Correct compatible to add soc name (bst,c1200-dwcmshc-sdhci)
- Remove all redundant property descriptions
- Drop invalid mmc_crm_base/size properties, use reg for all address ranges
- Clean up required properties to only essential entries
- Standardize example DTS format, fix reg syntax and property ordering
- Remove additionalProperties: true
---
 .../devicetree/bindings/mmc/bst,dwcmshc-sdhci.yaml | 70 ++++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/bst,dwcmshc-sdhci.yaml b/Documentation/devicetree/bindings/mmc/bst,dwcmshc-sdhci.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..7f16e6db39690cb7621d167bf7bc492f814ea693
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/bst,dwcmshc-sdhci.yaml
@@ -0,0 +1,70 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mmc/bst,dwcmshc-sdhci.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Black Sesame Technologies DWCMSHC SDHCI Controller
+
+maintainers:
+  - Ge Gordon <gordon.ge@bst.ai>
+
+allOf:
+  - $ref: sdhci-common.yaml#
+
+properties:
+  compatible:
+    const: bst,c1200-sdhci
+
+  reg:
+    items:
+      - description: Core SDHCI registers
+      - description: CRM registers
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    items:
+      - const: core
+
+  memory-region:
+    maxItems: 1
+
+  dma-coherent: true
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    bus {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        mmc@22200000 {
+            compatible = "bst,c1200-dwcmshc-sdhci";
+            reg = <0x0 0x22200000 0x0 0x1000>,
+                  <0x0 0x23006000 0x0 0x1000>;
+            interrupts = <GIC_SPI 144 IRQ_TYPE_LEVEL_HIGH>;
+            clocks = <&clk_mmc>;
+            clock-names = "core";
+            memory-region = <&mmc0_reserved>;
+            max-frequency = <200000000>;
+            bus-width = <8>;
+            non-removable;
+            dma-coherent;
+        };
+    };

-- 
2.43.0