dt-bindings: mmc: Add Loongson-2K SD/SDIO/eMMC controller binding

Add the Loongson-2K SoC's SD/SDIO/eMMC controller binding with DT schema
format using json-schema.

Signed-off-by: Binbin Zhou <[e-mail]>
Reviewed-by: Rob Herring (Arm) <[e-mail]>
Reviewed-by: Huacai Chen <[e-mail]>
Link: https://lore.kernel.org/r/94[e-mail]
Signed-off-by: Ulf Hansson <[e-mail]>

Documentation/devicetree/bindings/mmc/loongson,ls2k0500-mmc.yaml

···
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mmc/loongson,ls2k0500-mmc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: The SD/SDIO/eMMC host controller for Loongson-2K family SoCs
+
+description:
+  The MMC host controller on the Loongson-2K0500/2K1000 (using an externally
+  shared apbdma controller) provides the SD and SDIO device interfaces.
+
+maintainers:
+  - Binbin Zhou <[e-mail]>
+
+allOf:
+  - $ref: mmc-controller.yaml#
+
+properties:
+  compatible:
+    enum:
+      - loongson,ls2k0500-mmc
+      - loongson,ls2k1000-mmc
+
+  reg:
+    items:
+      - description: Loongson-2K MMC controller registers.
+      - description: APB DMA config register for Loongson-2K MMC controller.
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  dmas:
+    maxItems: 1
+
+  dma-names:
+    const: rx-tx
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - dmas
+  - dma-names
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/clock/loongson,ls2k-clk.h>
+
+    mmc@1fe2c000 {
+        compatible = "loongson,ls2k1000-mmc";
+        reg = <0x1fe2c000 0x68>,
+              <0x1fe00438 0x8>;
+        interrupt-parent = <&liointc0>;
+        interrupts = <31 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&clk LOONGSON2_APB_CLK>;
+        dmas = <&apbdma1 0>;
+        dma-names = "rx-tx";
+        bus-width = <4>;
+        cd-gpios = <&gpio0 22 GPIO_ACTIVE_LOW>;
+    };

MAINTAINERS

···
 F:	Documentation/devicetree/bindings/hwinfo/loongson,ls2k-chipid.yaml
 F:	drivers/soc/loongson/loongson2_guts.c
 
+LOONGSON-2 SOC SERIES MMC/SD/SDIO CONTROLLER DRIVER
+M:	Binbin Zhou <[e-mail]>
+L:	[e-mail]
+S:	Maintained
+F:	Documentation/devicetree/bindings/mmc/loongson,ls2k0500-mmc.yaml
+
 LOONGSON-2 SOC SERIES PM DRIVER
 M:	Yinbo Zhu <[e-mail]>
 L:	[e-mail]