[PATCH v6 1/9] dt-bindings: misc: Describe TI FPC202 dual port controller

[Romain Gantois <romain.gantois@bootlin.com>]

The FPC202 dual port controller serves as a low speed signal aggregator for
common port types, notably SFP. It provides access to I2C and low-speed
GPIO signals of a downstream device through a single upstream control
interface.

Up to two logical I2C addresses can be accessed on each of the FPC202's
ports. The port controller acts as an I2C translator (ATR). It converts
addresses of incoming and outgoing I2C transactions. One use case of this
is accessing two SFP modules at logical address 0x50 from the same upstream
I2C controller, using two different client aliases.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
---
 .../devicetree/bindings/misc/ti,fpc202.yaml        | 94 ++++++++++++++++++++++
 MAINTAINERS                                        |  6 ++
 2 files changed, 100 insertions(+)

diff --git a/Documentation/devicetree/bindings/misc/ti,fpc202.yaml b/Documentation/devicetree/bindings/misc/ti,fpc202.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..a8cb10f2d0df3fa5224f95f6f87467a8bce253bc
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/ti,fpc202.yaml
@@ -0,0 +1,94 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/misc/ti,fpc202.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TI FPC202 dual port controller with expanded IOs
+
+maintainers:
+  - Romain Gantois <romain.gantois@bootlin.com>
+
+allOf:
+  - $ref: /schemas/i2c/i2c-atr.yaml#
+
+properties:
+  compatible:
+    const: ti,fpc202
+
+  reg:
+    maxItems: 1
+
+  gpio-controller: true
+
+  "#gpio-cells":
+    const: 2
+
+  enable-gpios:
+    description:
+      Specifier for the GPIO connected to the EN pin.
+    maxItems: 1
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+patternProperties:
+  "^i2c@[0-1]$":
+    $ref: /schemas/i2c/i2c-controller.yaml#
+    description: Downstream device ports 0 and 1
+
+    properties:
+      reg:
+        maxItems: 1
+        description:
+          Downstream port ID
+
+    required:
+      - "#address-cells"
+      - "#size-cells"
+      - reg
+
+    unevaluatedProperties: false
+
+required:
+  - compatible
+  - reg
+  - gpio-controller
+  - "#gpio-cells"
+  - "#address-cells"
+  - "#size-cells"
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        i2c-atr@f {
+            compatible = "ti,fpc202";
+            reg = <0xf>;
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            gpio-controller;
+            #gpio-cells = <2>;
+
+            i2c@0 {
+                #address-cells = <1>;
+                #size-cells = <0>;
+                reg = <0>;
+            };
+
+            i2c@1 {
+                #address-cells = <1>;
+                #size-cells = <0>;
+                reg = <1>;
+            };
+        };
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 1e930c7a58b13d8bbe6bf133ba7b36aa24c2b5e0..2ef5c0d395b3668167dddbd27237a2177f85571e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -23497,6 +23497,12 @@ F:	drivers/misc/tifm*
 F:	drivers/mmc/host/tifm_sd.c
 F:	include/linux/tifm.h
 
+TI FPC202 DUAL PORT CONTROLLER
+M:	Romain Gantois <romain.gantois@bootlin.com>
+L:	linux-kernel@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/misc/ti,fpc202.yaml
+
 TI FPD-LINK DRIVERS
 M:	Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
 L:	linux-media@vger.kernel.org

-- 
2.47.1