spi: Convert DW SPI binding to DT schema

Modern device tree bindings are supposed to be created as YAML-files
in accordance with dt-schema. This commit replaces two DW SPI legacy
bare text bindings with YAML file. As before the bindings file states
that the corresponding dts node is supposed to be compatible either
with generic DW APB SSI controller or with Microsemi/Amazon/Renesas/Intel
vendors-specific controllers, to have registers, interrupts and clocks
properties. Though in case of Microsemi version of the controller
there must be two registers resources specified. Properties like
clock-names, reg-io-width, cs-gpio, num-cs, DMA and slave device
sub-nodes are optional.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-mips@vger.kernel.org
Link: https://lore.kernel.org/r/20200529182544.9807-1-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt

@@ -1,49 +0,0 @@
-Synopsys DesignWare AMBA 2.0 Synchronous Serial Interface.
-
-Required properties:
-- compatible : "snps,dw-apb-ssi" or "mscc,<soc>-spi", where soc is "ocelot" or
-  "jaguar2", or "amazon,alpine-dw-apb-ssi", or "snps,dwc-ssi-1.01a" or
-  "intel,keembay-ssi"
-- reg : The register base for the controller. For "mscc,<soc>-spi", a second
-  register set is required (named ICPU_CFG:SPI_MST)
-- interrupts : One interrupt, used by the controller.
-- #address-cells : <1>, as required by generic SPI binding.
-- #size-cells : <0>, also as required by generic SPI binding.
-- clocks : phandles for the clocks, see the description of clock-names below.
-   The phandle for the "ssi_clk" is required. The phandle for the "pclk" clock
-   is optional. If a single clock is specified but no clock-name, it is the
-   "ssi_clk" clock. If both clocks are listed, the "ssi_clk" must be first.
-
-Optional properties:
-- clock-names : Contains the names of the clocks:
-    "ssi_clk", for the core clock used to generate the external SPI clock.
-    "pclk", the interface clock, required for register access. If a clock domain
-     used to enable this clock then it should be named "pclk_clkdomain".
-- cs-gpios : Specifies the gpio pins to be used for chipselects.
-- num-cs : The number of chipselects. If omitted, this will default to 4.
-- reg-io-width : The I/O register width (in bytes) implemented by this
-  device.  Supported values are 2 or 4 (the default).
-- dmas : Phandle + identifiers of Tx and Rx DMA channels.
-- dma-names : Contains the names of the DMA channels. Must be "tx" and "rx".
-- resets : contains an entry for each entry in reset-names.
-	   See ../reset/reset.txt for details.
-- reset-names : must contain "spi"
-
-Child nodes as per the generic SPI binding.
-
-Example:
-
-	spi@fff00000 {
-		compatible = "snps,dw-apb-ssi";
-		reg = <0xfff00000 0x1000>;
-		interrupts = <0 154 4>;
-		#address-cells = <1>;
-		#size-cells = <0>;
-		clocks = <&spi_m_clk>;
-		num-cs = <2>;
-		cs-gpios = <&gpio0 13 0>,
-			   <&gpio0 14 0>;
-		resets = <&rst SPIM0_RST>;
-		reset-names = "spi";
-	};
-

Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml

@@ -0,0 +1,133 @@
+# SPDX-License-Identifier: GPL-2.0-only
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/snps,dw-apb-ssi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Synopsys DesignWare AMBA 2.0 Synchronous Serial Interface
+
+maintainers:
+  - Mark Brown <broonie@kernel.org>
+
+allOf:
+  - $ref: "spi-controller.yaml#"
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - mscc,ocelot-spi
+              - mscc,jaguar2-spi
+    then:
+      properties:
+        reg:
+          minItems: 2
+
+properties:
+  compatible:
+    oneOf:
+      - description: Generic DW SPI Controller
+        enum:
+          - snps,dw-apb-ssi
+          - snps,dwc-ssi-1.01a
+      - description: Microsemi Ocelot/Jaguar2 SoC SPI Controller
+        items:
+          - enum:
+              - mscc,ocelot-spi
+              - mscc,jaguar2-spi
+          - const: snps,dw-apb-ssi
+      - description: Amazon Alpine SPI Controller
+        const: amazon,alpine-dw-apb-ssi
+      - description: Renesas RZ/N1 SPI Controller
+        items:
+          - const: renesas,rzn1-spi
+          - const: snps,dw-apb-ssi
+      - description: Intel Keem Bay SPI Controller
+        const: intel,keembay-ssi
+
+  reg:
+    minItems: 1
+    items:
+      - description: DW APB SSI controller memory mapped registers
+      - description: SPI MST region map
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    minItems: 1
+    items:
+      - description: SPI Controller reference clock source
+      - description: APB interface clock source
+
+  clock-names:
+    minItems: 1
+    items:
+      - const: ssi_clk
+      - const: pclk
+
+  resets:
+    maxItems: 1
+
+  reset-names:
+    const: spi
+
+  reg-io-width:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: I/O register width (in bytes) implemented by this device
+    default: 4
+    enum: [ 2, 4 ]
+
+  num-cs:
+    default: 4
+    minimum: 1
+    maximum: 4
+
+  dmas:
+    items:
+      - description: TX DMA Channel
+      - description: RX DMA Channel
+
+  dma-names:
+    items:
+      - const: tx
+      - const: rx
+
+patternProperties:
+  "^.*@[0-9a-f]+$":
+    type: object
+    properties:
+      reg:
+        minimum: 0
+        maximum: 3
+
+      spi-rx-bus-width:
+        const: 1
+
+      spi-tx-bus-width:
+        const: 1
+
+unevaluatedProperties: false
+
+required:
+  - compatible
+  - reg
+  - "#address-cells"
+  - "#size-cells"
+  - interrupts
+  - clocks
+
+examples:
+  - |
+    spi@fff00000 {
+      compatible = "snps,dw-apb-ssi";
+      reg = <0xfff00000 0x1000>;
+      #address-cells = <1>;
+      #size-cells = <0>;
+      interrupts = <0 154 4>;
+      clocks = <&spi_m_clk>;
+      num-cs = <2>;
+      cs-gpios = <&gpio0 13 0>,
+                 <&gpio0 14 0>;
+    };
+...

Documentation/devicetree/bindings/spi/spi-dw.txt

@@ -1,24 +0,0 @@
-Synopsys DesignWare SPI master
-
-Required properties:
-- compatible: should be "snps,designware-spi"
-- #address-cells: see spi-bus.txt
-- #size-cells: see spi-bus.txt
-- reg: address and length of the spi master registers
-- interrupts: should contain one interrupt
-- clocks: spi clock phandle
-- num-cs: see spi-bus.txt
-
-Optional properties:
-- cs-gpios: see spi-bus.txt
-
-Example:
-
-spi: spi@4020a000 {
-	compatible = "snps,designware-spi";
-	interrupts = <11 1>;
-	reg = <0x4020a000 0x1000>;
-	clocks = <&pclk>;
-	num-cs = <2>;
-	cs-gpios = <&banka 0 0>;
-};