dts: bindings: pinctrl: add pincfg-node-group

When using group based representation on pinctrl nodes, the pin
configuration properties end up being at the grand-children level, so
the `pincfg-node.yaml` file can't be used.

Having a common file that can be used for both cases would require
tooling changes, so for now a copy that operated at the grand-children
level has been created.

Signed-off-by: Gerard Marull-Paretas <[email protected]>

Author: gmarull

dts/bindings/pinctrl/pincfg-node-group.yaml

@@ -0,0 +1,165 @@
+# Copyright (c) 2020, Linaro Limited
+# SPDX-License-Identifier: Apache-2.0
+
+description: |
+  Generic pin configuration schema.
+
+  This file is equivalent to pincfg-node.yaml but inserts properties at a
+  grandchildren level, useful for group based representation.
+
+child-binding:
+  child-binding:
+    description: |
+      Many data items that are represented in a pin configuration node are
+      common and generic. Pin control bindings should use the properties
+      defined below where they are applicable; not all of these properties are
+      relevant or useful for all hardware or binding structures. Each
+      individual binding document should state which of these generic
+      properties, if any, are used, and the structure of the DT nodes that
+      contain these properties.
+
+      This is based on Linux, documentation:
+        https://www.kernel.org/doc/Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml
+
+    properties:
+      bias-disable:
+        required: false
+        type: boolean
+        description: disable any pin bias
+
+      bias-high-impedance:
+        required: false
+        type: boolean
+        description: high impedance mode ("third-state", "floating")
+
+      bias-bus-hold:
+        required: false
+        type: boolean
+        description: latch weakly
+
+      bias-pull-up:
+        required: false
+        type: boolean
+        description: enable pull-up resistor
+
+      bias-pull-down:
+        required: false
+        type: boolean
+        description: enable pull-down resistor
+
+      bias-pull-pin-default:
+        required: false
+        type: boolean
+        description: use pin's default pull state
+
+      drive-push-pull:
+        required: false
+        type: boolean
+        description: drive actively high and low
+
+      drive-open-drain:
+        required: false
+        type: boolean
+        description: drive with open drain (hardware AND)
+
+      drive-open-source:
+        required: false
+        type: boolean
+        description: drive with open source (hardware OR)
+
+      drive-strength:
+        required: false
+        type: int
+        description: maximum sink or source current in mA
+
+      drive-strength-microamp:
+        required: false
+        type: int
+        description: maximum sink or source current in μA
+
+      input-enable:
+        required: false
+        type: boolean
+        description: |
+          enable input on pin (no effect on output, such as enabling an input
+          buffer)
+
+      input-disable:
+        required: false
+        type: boolean
+        description: |
+          disable input on pin (no effect on output, such as disabling an input
+          buffer)
+
+      input-schmitt-enable:
+        required: false
+        type: boolean
+        description: enable schmitt-trigger mode
+
+      input-schmitt-disable:
+        required: false
+        type: boolean
+        description: disable schmitt-trigger mode
+
+      input-debounce:
+        required: false
+        type: int
+        description: |
+          Takes the debounce time in μsec, as argument or 0 to disable debouncing
+
+      power-source:
+        required: false
+        type: int
+        description: select between different power supplies
+
+      low-power-enable:
+        required: false
+        type: boolean
+        description: enable low power mode
+
+      low-power-disable:
+        required: false
+        type: boolean
+        description: disable low power mode
+
+      output-disable:
+        required: false
+        type: boolean
+        description: disable output on a pin (such as disable an output buffer)
+
+      output-enable:
+        required: false
+        type: boolean
+        description: |
+          enable output on a pin without actively driving it (such as enabling
+          an output buffer)
+
+      output-low:
+        required: false
+        type: boolean
+        description: set the pin to output mode with low level
+
+      output-high:
+        required: false
+        type: boolean
+        description: set the pin to output mode with high level
+
+      sleep-hardware-state:
+        required: false
+        type: boolean
+        description: |
+          indicate this is sleep related state which will be programmed into
+          the registers for the sleep state
+
+      slew-rate:
+        required: false
+        type: int
+        description: set the slew rate
+
+      skew-delay:
+        required: false
+        type: int
+        description: |
+          This affects the expected clock skew on input pins and the delay
+          before latching a value to an output pin. Typically indicates how
+          many double-inverters are used to delay the signal.