[PATCH v4] dt-bindings: Create DT bindings for SATA controllers

[Linus Walleij <linus.walleij@linaro.org>]

I need to create subnodes for drives connected to SATA
host controllers, and this needs to be supported
generally, so create a common YAML binding for
"sata" that will support subnodes with ports.

This has been designed as a subset of
ata/ahci-platform.txt with the bare essentials and
should be possible to extend or superset to cover the
common bindings.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v3->v4:
- Drop any master/slave terminology: SATA has one drive
  per port or up to 15 drives behind a multiplexer.
- Drop RFC notation, this feels pretty finished.
ChangeLog v2->v3:
- Split off into its own RFC patch
- Only support sata-port@ in this binding
- Opt to support devices 0..14 on the sata-port in
  line with ahci-platforn.txt not modeling the port
  multiplier in the device tree at all.
ChangeLog v1->v2:
- Use ide@ and sata@ as node names.
- Use ide-port@ and sata-port@ for the ports toward the
  drives, rather than letting the subnodes be the drives
  themselves.
---
 .../devicetree/bindings/ata/sata-common.yaml  | 50 +++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/ata/sata-common.yaml

diff --git a/Documentation/devicetree/bindings/ata/sata-common.yaml b/Documentation/devicetree/bindings/ata/sata-common.yaml
new file mode 100644
index 000000000000..41f590629fbf
--- /dev/null
+++ b/Documentation/devicetree/bindings/ata/sata-common.yaml
@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/ata/sata-common.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Common Properties for Serial AT attachment (SATA) controllers
+
+maintainers:
+  - Linus Walleij <linus.walleij@linaro.org>
+
+description: |
+  This document defines device tree properties common to most Serial
+  AT attachment (SATA) storage devices. It doesn't constitute a device tree
+  binding specification by itself but is meant to be referenced by device
+  tree bindings.
+
+  The SATA controller-specific device tree bindings are responsible for
+  defining whether each property is required or optional.
+
+properties:
+  $nodename:
+    pattern: "^sata(@.*)?$"
+    description:
+      Specifies the host controller node. SATA host controller nodes are named
+      "sata"
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+patternProperties:
+  "^sata-port@[0-1]$":
+    description: |
+      DT nodes for ports connected on the SATA host. The SATA port
+      nodes will be named "sata-port".
+    type: object
+
+    properties:
+      reg:
+        minimum: 0
+        maximum: 14
+        description:
+          The ID number of the drive port SATA can potentially use a port
+          multiplier making it possible to connect up to 15 disks to a single
+          SATA port.
+
+...
-- 
2.21.0