ASoC: dt-bindings: add schema for rockchip SAI controllers

Rockchip introduced a new audio controller called the "Serial Audio
Interface", or "SAI" for short, on some of their newer SoCs. In
particular, this controller is used several times on the RK3576 SoC.

Add a schema for it, with only an RK3576 compatible for now. Other SoCs
may follow as mainline support for them lands.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20250410-rk3576-sai-v2-5-c64608346be3@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: Nicolas Frattaroli

Documentation/devicetree/bindings/sound/rockchip,rk3576-sai.yaml

@@ -0,0 +1,144 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sound/rockchip,rk3576-sai.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Rockchip Serial Audio Interface Controller
+
+description:
+  The Rockchip Serial Audio Interface (SAI) controller is a flexible audio
+  controller that implements the I2S, I2S/TDM and the PDM standards.
+
+maintainers:
+  - Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
+
+allOf:
+  - $ref: dai-common.yaml#
+
+properties:
+  compatible:
+    const: rockchip,rk3576-sai
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  dmas:
+    minItems: 1
+    maxItems: 2
+
+  dma-names:
+    minItems: 1
+    items:
+      - enum: [tx, rx]
+      - const: rx
+
+  clocks:
+    items:
+      - description: master audio clock
+      - description: AHB clock driving the interface
+
+  clock-names:
+    items:
+      - const: mclk
+      - const: hclk
+
+  resets:
+    minItems: 1
+    items:
+      - description: reset for the mclk domain
+      - description: reset for the hclk domain
+
+  reset-names:
+    minItems: 1
+    items:
+      - const: m
+      - const: h
+
+  port:
+    $ref: audio-graph-port.yaml#
+    unevaluatedProperties: false
+
+  power-domains:
+    maxItems: 1
+
+  "#sound-dai-cells":
+    const: 0
+
+  rockchip,sai-rx-route:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    description:
+      Defines the mapping of the controller's SDI ports to actual input lanes,
+      as well as the number of input lanes.
+      rockchip,sai-rx-route = <3> would mean sdi3 is receiving from data0, and
+      that there is only one receiving lane.
+      This property's absence is to be understood as only one receiving lane
+      being used if the controller has capture capabilities.
+    maxItems: 4
+    items:
+      minimum: 0
+      maximum: 3
+
+  rockchip,sai-tx-route:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    description:
+      Defines the mapping of the controller's SDO ports to actual output lanes,
+      as well as the number of output lanes.
+      rockchip,sai-tx-route = <3> would mean sdo3 is sending to data0, and
+      that there is only one transmitting lane.
+      This property's absence is to be understood as only one transmitting lane
+      being used if the controller has playback capabilities.
+    maxItems: 4
+    items:
+      minimum: 0
+      maximum: 3
+
+required:
+  - compatible
+  - reg
+  - dmas
+  - dma-names
+  - clocks
+  - clock-names
+  - "#sound-dai-cells"
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/rockchip,rk3576-cru.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/pinctrl/rockchip.h>
+    #include <dt-bindings/power/rockchip,rk3576-power.h>
+    #include <dt-bindings/reset/rockchip,rk3576-cru.h>
+
+    bus {
+        #address-cells = <2>;
+        #size-cells = <2>;
+        sai1: sai@2a610000 {
+            compatible = "rockchip,rk3576-sai";
+            reg = <0x0 0x2a610000 0x0 0x1000>;
+            interrupts = <GIC_SPI 188 IRQ_TYPE_LEVEL_HIGH>;
+            clocks = <&cru MCLK_SAI1_8CH>, <&cru HCLK_SAI1_8CH>;
+            clock-names = "mclk", "hclk";
+            dmas = <&dmac0 2>, <&dmac0 3>;
+            dma-names = "tx", "rx";
+            power-domains = <&power RK3576_PD_AUDIO>;
+            resets = <&cru SRST_M_SAI1_8CH>, <&cru SRST_H_SAI1_8CH>;
+            reset-names = "m", "h";
+            pinctrl-names = "default";
+            pinctrl-0 = <&sai1m0_lrck
+                         &sai1m0_sclk
+                         &sai1m0_sdi0
+                         &sai1m0_sdo0
+                         &sai1m0_sdo1
+                         &sai1m0_sdo2
+                         &sai1m0_sdo3>;
+            rockchip,sai-tx-route = <3 1 2 0>;
+            #sound-dai-cells = <0>;
+        };
+    };

MAINTAINERS

@@ -20913,6 +20913,12 @@ F:	Documentation/devicetree/bindings/sound/rockchip,rk3308-codec.yaml
 F:	sound/soc/codecs/rk3308_codec.c
 F:	sound/soc/codecs/rk3308_codec.h
 
+ROCKCHIP SAI DRIVER
+M:	Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
+L:	linux-rockchip@lists.infradead.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/sound/rockchip,rk3576-sai.yaml
+
 ROCKCHIP VIDEO DECODER DRIVER
 M:	Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
 L:	linux-media@vger.kernel.org