spi: dt-bindings: marvell,mmp2-ssp: Merge PXA SSP into schema

The Marvell PXA SSP block is the same or similiar to the MMP2 variant.
The only difference in the binding is the PXA version supports DMA (and
that's probably a binding difference rather than an actual h/w
difference).

The old binding didn't belong under 'serial' as it is not a UART. The
SSP block also supports audio devices, so 'spi' is not a perfect fit
either. As the existing schema for MMP2 is there, just leave things
as-is.

The examples in the old text binding were pretty out of sync with
reality. 'clock-names' and 'ssp-id' aren't documented nor used.

Cc: Andy Shevchenko <[e-mail]>
Signed-off-by: Rob Herring (Arm) <[e-mail]>
Link: https://msgid.link/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

Documentation/devicetree/bindings/serial/mrvl,pxa-ssp.txt

···
-Device tree bindings for Marvell PXA SSP ports
-
-Required properties:
-
-	- compatible:	Must be one of
-				mrvl,pxa25x-ssp
-				mvrl,pxa25x-nssp
-				mrvl,pxa27x-ssp
-				mrvl,pxa3xx-ssp
-				mvrl,pxa168-ssp
-				mrvl,pxa910-ssp
-				mrvl,ce4100-ssp
-
-	- reg:		The memory base
-	- dmas:		Two dma phandles, one for rx, one for tx
-	- dma-names:	Must be "rx", "tx"
-
-
-Example for PXA3xx:
-
-	ssp0: ssp@41000000 {
-		compatible = "mrvl,pxa3xx-ssp";
-		reg = <0x41000000 0x40>;
-		ssp-id = <1>;
-		interrupts = <24>;
-		clock-names = "pxa27x-ssp.0";
-		dmas = <&dma 13
-			&dma 14>;
-		dma-names = "rx", "tx";
-	};
-
-	ssp1: ssp@41700000 {
-		compatible = "mrvl,pxa3xx-ssp";
-		reg = <0x41700000 0x40>;
-		ssp-id = <2>;
-		interrupts = <16>;
-		clock-names = "pxa27x-ssp.1";
-		dmas = <&dma 15
-			&dma 16>;
-		dma-names = "rx", "tx";
-	};
-
-	ssp2: ssp@41900000 {
-		compatibl3 = "mrvl,pxa3xx-ssp";
-		reg = <0x41900000 0x40>;
-		ssp-id = <3>;
-		interrupts = <0>;
-		clock-names = "pxa27x-ssp.2";
-		dmas = <&dma 66
-			&dma 67>;
-		dma-names = "rx", "tx";
-	};
-
-	ssp3: ssp@41a00000 {
-		compatible = "mrvl,pxa3xx-ssp";
-		reg = <0x41a00000 0x40>;
-		ssp-id = <4>;
-		interrupts = <13>;
-		clock-names = "pxa27x-ssp.3";
-		dmas = <&dma 2
-			&dma 3>;
-		dma-names = "rx", "tx";
-	};
-

Documentation/devicetree/bindings/spi/marvell,mmp2-ssp.yaml

···
 maintainers:
   - Lubomir Rintel <[e-mail]>
 
-allOf:
-  - $ref: spi-controller.yaml#
-
 properties:
   compatible:
-    const: marvell,mmp2-ssp
+    enum:
+      - marvell,mmp2-ssp
+      - mrvl,ce4100-ssp
+      - mvrl,pxa168-ssp
+      - mrvl,pxa25x-ssp
+      - mvrl,pxa25x-nssp
+      - mrvl,pxa27x-ssp
+      - mrvl,pxa3xx-ssp
+      - mrvl,pxa910-ssp
 
   interrupts:
     maxItems: 1
···
 
   clocks:
     maxItems: 1
+
+  dmas:
+    items:
+      - description: Receive DMA
+      - description: Transmit DMA
+
+  dma-names:
+    items:
+      - const: rx
+      - const: tx
 
   ready-gpios:
     description: |
···
 
 dependencies:
   ready-gpios: [ spi-slave ]
+
+allOf:
+  - $ref: spi-controller.yaml#
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: marvell,mmp2-ssp
+    then:
+      properties:
+        dmas: false
+        dma-names: false
 
 unevaluatedProperties: false