spi: spi-fsl-dspi: DSPI support for NXP S32G

Merge series from James Clark <james.clark@linaro.org>:

DT and driver changes for DSPI on S32G platforms. First 3 commits are
fixes for various edge cases which also apply to other platforms.
Remaining commits add new S32G registers and device settings, some S32G
specific fixes and then finally add the DT compatibles and binding docs.

Tested in both host and target mode on S32G-VNP-RDB3 by transferring to
an external device over spi1 using spidev_test.c

Author: broonie

Documentation/devicetree/bindings/spi/fsl,dspi.yaml

@@ -23,6 +23,7 @@ properties:
           - fsl,ls2080a-dspi
           - fsl,ls2085a-dspi
           - fsl,lx2160a-dspi
+          - nxp,s32g2-dspi
       - items:
           - enum:
               - fsl,ls1012a-dspi
@@ -37,6 +38,9 @@ properties:
       - items:
           - const: fsl,lx2160a-dspi
           - const: fsl,ls2085a-dspi
+      - items:
+          - const: nxp,s32g3-dspi
+          - const: nxp,s32g2-dspi
 
   reg:
     maxItems: 1
@@ -114,3 +118,17 @@ examples:
             spi-cs-hold-delay-ns = <50>;
         };
     };
+  # S32G3 in target mode
+  - |
+    spi@401d4000 {
+        compatible = "nxp,s32g3-dspi", "nxp,s32g2-dspi";
+        reg = <0x401d4000 0x1000>;
+        interrupts = <GIC_SPI 85 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&clks 26>;
+        clock-names = "dspi";
+        spi-num-chipselects = <8>;
+        bus-num = <0>;
+        dmas = <&edma0 0 7>, <&edma0 0 8>;
+        dma-names = "tx", "rx";
+        spi-slave;
+    };

drivers/spi/Kconfig

@@ -647,10 +647,10 @@ config SPI_FSL_SPI
 config SPI_FSL_DSPI
 	tristate "Freescale DSPI controller"
 	select REGMAP_MMIO
-	depends on SOC_VF610 || SOC_LS1021A || ARCH_LAYERSCAPE || M5441x || COMPILE_TEST
+	depends on ARCH_MXC || ARCH_NXP || M54541x || COMPILE_TEST
 	help
 	  This enables support for the Freescale DSPI controller in master
-	  mode. VF610, LS1021A and ColdFire platforms uses the controller.
+	  mode. S32, VF610, LS1021A and ColdFire platforms uses the controller.
 
 config SPI_FSL_ESPI
 	tristate "Freescale eSPI controller"