dt-bindings: ata: ahci: Add DWC AHCI SATA controller DT schema

Synopsys AHCI SATA controller is mainly compatible with the generic AHCI
SATA controller except a few peculiarities and the platform environment
requirements. In particular it can have at least two reference clocks to
feed up its AHB/AXI interface and SATA PHYs domain and at least one reset
control for the application clock domain. In addition to that the DMA
interface of each port can be tuned up to work with the predefined maximum
data chunk size. Note unlike generic AHCI controller DWC AHCI can't have
more than 8 ports. All of that is reflected in the new DWC AHCI SATA
device DT binding.

Note the DWC AHCI SATA controller DT-schema has been created in a way so
to be reused for the vendor-specific DT-schemas (see for example the
"snps,dwc-ahci" compatible string binding). One of which we are about to
introduce.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

Documentation/devicetree/bindings/ata/ahci-platform.yaml

@@ -30,8 +30,6 @@ select:
           - marvell,armada-3700-ahci
           - marvell,armada-8k-ahci
           - marvell,berlin2q-ahci
-          - snps,dwc-ahci
-          - snps,spear-ahci
   required:
     - compatible
 
@@ -48,17 +46,11 @@ properties:
               - marvell,berlin2-ahci
               - marvell,berlin2q-ahci
           - const: generic-ahci
-      - items:
-          - enum:
-              - rockchip,rk3568-dwc-ahci
-          - const: snps,dwc-ahci
       - enum:
           - cavium,octeon-7130-ahci
           - hisilicon,hisi-ahci
           - ibm,476gtr-ahci
           - marvell,armada-3700-ahci
-          - snps,dwc-ahci
-          - snps,spear-ahci
 
   reg:
     minItems: 1

Documentation/devicetree/bindings/ata/snps,dwc-ahci-common.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/ata/snps,dwc-ahci-common.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Synopsys DWC AHCI SATA controller properties
+
+maintainers:
+  - Serge Semin <fancer.lancer@gmail.com>
+
+description:
+  This document defines device tree schema for the generic Synopsys DWC
+  AHCI controller properties.
+
+select: false
+
+allOf:
+  - $ref: ahci-common.yaml#
+
+properties:
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    description:
+      Basic DWC AHCI SATA clock sources like application AXI/AHB BIU clock,
+      PM-alive clock, RxOOB detection clock, embedded PHYs reference (Rx/Tx)
+      clock, etc.
+    minItems: 1
+    maxItems: 4
+
+  clock-names:
+    minItems: 1
+    maxItems: 4
+    items:
+      oneOf:
+        - description: Application APB/AHB/AXI BIU clock
+          enum:
+            - pclk
+            - aclk
+            - hclk
+            - sata
+        - description: Power Module keep-alive clock
+          const: pmalive
+        - description: RxOOB detection clock
+          const: rxoob
+        - description: SATA Ports reference clock
+          const: ref
+
+  resets:
+    description:
+      At least basic application and reference clock domains resets are
+      normally supported by the DWC AHCI SATA controller.
+    minItems: 1
+    maxItems: 4
+
+  reset-names:
+    minItems: 1
+    maxItems: 4
+    items:
+      oneOf:
+        - description: Application AHB/AXI BIU clock domain reset control
+          enum:
+            - arst
+            - hrst
+        - description: Power Module keep-alive clock domain reset control
+          const: pmalive
+        - description: RxOOB detection clock domain reset control
+          const: rxoob
+        - description: Reference clock domain reset control
+          const: ref
+
+patternProperties:
+  "^sata-port@[0-9a-e]$":
+    $ref: '#/$defs/dwc-ahci-port'
+
+additionalProperties: true
+
+$defs:
+  dwc-ahci-port:
+    $ref: /schemas/ata/ahci-common.yaml#/$defs/ahci-port
+
+    properties:
+      reg:
+        minimum: 0
+        maximum: 7
+
+      snps,tx-ts-max:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description: Maximal size of Tx DMA transactions in FIFO words
+        enum: [ 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024 ]
+
+      snps,rx-ts-max:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description: Maximal size of Rx DMA transactions in FIFO words
+        enum: [ 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024 ]
+
+...

Documentation/devicetree/bindings/ata/snps,dwc-ahci.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/ata/snps,dwc-ahci.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Synopsys DWC AHCI SATA controller
+
+maintainers:
+  - Serge Semin <fancer.lancer@gmail.com>
+
+description:
+  This document defines device tree bindings for the generic Synopsys DWC
+  implementation of the AHCI SATA controller.
+
+allOf:
+  - $ref: snps,dwc-ahci-common.yaml#
+
+properties:
+  compatible:
+    oneOf:
+      - description: Synopsys AHCI SATA-compatible devices
+        const: snps,dwc-ahci
+      - description: SPEAr1340 AHCI SATA device
+        const: snps,spear-ahci
+      - description: Rockhip RK3568 AHCI controller
+        items:
+          - const: rockchip,rk3568-dwc-ahci
+          - const: snps,dwc-ahci
+
+patternProperties:
+  "^sata-port@[0-9a-e]$":
+    $ref: /schemas/ata/snps,dwc-ahci-common.yaml#/$defs/dwc-ahci-port
+
+    unevaluatedProperties: false
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/ata/ahci.h>
+
+    sata@122f0000 {
+      compatible = "snps,dwc-ahci";
+      reg = <0x122F0000 0x1ff>;
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      interrupts = <GIC_SPI 115 IRQ_TYPE_LEVEL_HIGH>;
+
+      clocks = <&clock1>, <&clock2>;
+      clock-names = "aclk", "ref";
+
+      phys = <&sata_phy>;
+      phy-names = "sata-phy";
+
+      ports-implemented = <0x1>;
+
+      sata-port@0 {
+        reg = <0>;
+
+        hba-port-cap = <HBA_PORT_FBSCP>;
+
+        snps,tx-ts-max = <512>;
+        snps,rx-ts-max = <512>;
+      };
+    };
+
+...