dt-bindings: pinctrl: Convert generic pin mux and config properties to schema

As pinctrl bindings have a flexible structure and no standard child node
naming convention, creating a single pinctrl schema doesn't work. Instead,
create schemas for the pin mux and config nodes which device pinctrl schema
can reference.

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-gpio@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20191107224254.15712-1-robh@kernel.orgSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/pincfg-node.yaml

+# SPDX-License-Identifier: GPL-2.0-only
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pinctrl/pincfg-node.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Generic pin configuration node schema
+
+maintainers:
+  - Linus Walleij <linus.walleij@linaro.org>
+
+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.
+
+properties:
+  bias-disable:
+    type: boolean
+    description: disable any pin bias
+
+  bias-high-impedance:
+    type: boolean
+    description: high impedance mode ("third-state", "floating")
+
+  bias-bus-hold:
+    type: boolean
+    description: latch weakly
+
+  bias-pull-up:
+    oneOf:
+      - type: boolean
+      - $ref: /schemas/types.yaml#/definitions/uint32
+    description: pull up the pin. Takes as optional argument on hardware
+      supporting it the pull strength in Ohm.
+
+  bias-pull-down:
+    oneOf:
+      - type: boolean
+      - $ref: /schemas/types.yaml#/definitions/uint32
+    description: pull down the pin. Takes as optional argument on hardware
+      supporting it the pull strength in Ohm.
+
+  bias-pull-pin-default:
+    oneOf:
+      - type: boolean
+      - $ref: /schemas/types.yaml#/definitions/uint32
+    description: use pin-default pull state. Takes as optional argument on
+      hardware supporting it the pull strength in Ohm.
+
+  drive-push-pull:
+    type: boolean
+    description: drive actively high and low
+
+  drive-open-drain:
+    type: boolean
+    description: drive with open drain
+
+  drive-open-source:
+    type: boolean
+    description: drive with open source
+
+  drive-strength:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: sink or source at most X mA
+
+  drive-strength-microamp:
+    description: sink or source at most X uA
+
+  input-enable:
+    type: boolean
+    description: enable input on pin (no effect on output, such as
+      enabling an input buffer)
+
+  input-disable:
+    type: boolean
+    description: disable input on pin (no effect on output, such as
+      disabling an input buffer)
+
+  input-schmitt-enable:
+    type: boolean
+    description: enable schmitt-trigger mode
+
+  input-schmitt-disable:
+    type: boolean
+    description: disable schmitt-trigger mode
+
+  input-debounce:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: Takes the debounce time in usec as argument or 0 to disable
+      debouncing
+
+  power-source:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: select between different power supplies
+
+  low-power-enable:
+    type: boolean
+    description: enable low power mode
+
+  low-power-disable:
+    type: boolean
+    description: disable low power mode
+
+  output-disable:
+    type: boolean
+    description: disable output on a pin (such as disable an output buffer)
+
+  output-enable:
+    type: boolean
+    description: enable output on a pin without actively driving it
+      (such as enabling an output buffer)
+
+  output-low:
+    type: boolean
+    description: set the pin to output mode with low level
+
+  output-high:
+    type: boolean
+    description: set the pin to output mode with high level
+
+  sleep-hardware-state:
+    type: boolean
+    description: indicate this is sleep related state which will be
+      programmed into the registers for the sleep state.
+
+  slew-rate:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: set the slew rate
+
+  skew-delay:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    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.

Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt

@@ -141,196 +141,8 @@ controller device.
 
 == Generic pin multiplexing node content ==
 
-pin multiplexing nodes:
-
-function		- the mux function to select
-groups			- the list of groups to select with this function
-			  (either this or "pins" must be specified)
-pins			- the list of pins to select with this function (either
-			  this or "groups" must be specified)
-
-Example:
-
-state_0_node_a {
-	uart0 {
-		function = "uart0";
-		groups = "u0rxtx", "u0rtscts";
-	};
-};
-state_1_node_a {
-	spi0 {
-		function = "spi0";
-		groups = "spi0pins";
-	};
-};
-state_2_node_a {
-	function = "i2c0";
-	pins = "mfio29", "mfio30";
-};
-
-Optionally an alternative binding can be used if more suitable depending on the
-pin controller hardware. For hardware where there is a large number of identical
-pin controller instances, naming each pin and function can easily become
-unmaintainable. This is especially the case if the same controller is used for
-different pins and functions depending on the SoC revision and packaging.
-
-For cases like this, the pin controller driver may use pinctrl-pin-array helper
-binding with a hardware based index and a number of pin configuration values:
-
-pincontroller {
-	... /* Standard DT properties for the device itself elided */
-	#pinctrl-cells = <2>;
-
-	state_0_node_a {
-		pinctrl-pin-array = <
-			0 A_DELAY_PS(0) G_DELAY_PS(120)
-			4 A_DELAY_PS(0) G_DELAY_PS(360)
-			...
-		>;
-	};
-	...
-};
-
-Above #pinctrl-cells specifies the number of value cells in addition to the
-index of the registers. This is similar to the interrupts-extended binding with
-one exception. There is no need to specify the phandle for each entry as that
-is already known as the defined pins are always children of the pin controller
-node. Further having the phandle pointing to another pin controller would not
-currently work as the pinctrl framework uses named modes to group pins for each
-pin control device.
-
-The index for pinctrl-pin-array must relate to the hardware for the pinctrl
-registers, and must not be a virtual index of pin instances. The reason for
-this is to avoid mapping of the index in the dts files and the pin controller
-driver as it can change.
-
-For hardware where pin multiplexing configurations have to be specified for
-each single pin the number of required sub-nodes containing "pin" and
-"function" properties can quickly escalate and become hard to write and
-maintain.
-
-For cases like this, the pin controller driver may use the pinmux helper
-property, where the pin identifier is provided with mux configuration settings
-in a pinmux group. A pinmux group consists of the pin identifier and mux
-settings represented as a single integer or an array of integers.
-
-The pinmux property accepts an array of pinmux groups, each of them describing
-a single pin multiplexing configuration.
-
-pincontroller {
-	state_0_node_a {
-		pinmux = <PINMUX_GROUP>, <PINMUX_GROUP>, ...;
-	};
-};
-
-Each individual pin controller driver bindings documentation shall specify
-how pin IDs and pin multiplexing configuration are defined and assembled
-together in a pinmux group.
+See pinmux-node.yaml
 
 == Generic pin configuration node content ==
 
-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.
-
-Supported generic properties are:
-
-pins			- the list of pins that properties in the node
-			  apply to (either this, "group" or "pinmux" has to be
-			  specified)
-group			- the group to apply the properties to, if the driver
-			  supports configuration of whole groups rather than
-			  individual pins (either this, "pins" or "pinmux" has
-			  to be specified)
-pinmux			- the list of numeric pin ids and their mux settings
-			  that properties in the node apply to (either this,
-			  "pins" or "groups" have to be specified)
-bias-disable		- disable any pin bias
-bias-high-impedance	- high impedance mode ("third-state", "floating")
-bias-bus-hold		- latch weakly
-bias-pull-up		- pull up the pin
-bias-pull-down		- pull down the pin
-bias-pull-pin-default	- use pin-default pull state
-drive-push-pull		- drive actively high and low
-drive-open-drain	- drive with open drain
-drive-open-source	- drive with open source
-drive-strength		- sink or source at most X mA
-drive-strength-microamp	- sink or source at most X uA
-input-enable		- enable input on pin (no effect on output, such as
-			  enabling an input buffer)
-input-disable		- disable input on pin (no effect on output, such as
-			  disabling an input buffer)
-input-schmitt-enable	- enable schmitt-trigger mode
-input-schmitt-disable	- disable schmitt-trigger mode
-input-debounce		- debounce mode with debound time X
-power-source		- select between different power supplies
-low-power-enable	- enable low power mode
-low-power-disable	- disable low power mode
-output-disable		- disable output on a pin (such as disable an output
-			  buffer)
-output-enable		- enable output on a pin without actively driving it
-			  (such as enabling an output buffer)
-output-low		- set the pin to output mode with low level
-output-high		- set the pin to output mode with high level
-sleep-hardware-state	- indicate this is sleep related state which will be programmed
-			  into the registers for the sleep state.
-slew-rate		- set the slew rate
-skew-delay		- 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.
-
-For example:
-
-state_0_node_a {
-	cts_rxd {
-		pins = "GPIO0_AJ5", "GPIO2_AH4"; /* CTS+RXD */
-		bias-pull-up;
-	};
-};
-state_1_node_a {
-	rts_txd {
-		pins = "GPIO1_AJ3", "GPIO3_AH3"; /* RTS+TXD */
-		output-high;
-	};
-};
-state_2_node_a {
-	foo {
-		group = "foo-group";
-		bias-pull-up;
-	};
-};
-state_3_node_a {
-	mux {
-		pinmux = <GPIOx_PINm_MUXn>, <GPIOx_PINj_MUXk)>;
-		input-enable;
-	};
-};
-
-Some of the generic properties take arguments. For those that do, the
-arguments are described below.
-
-- pins takes a list of pin names or IDs as a required argument. The specific
-  binding for the hardware defines:
-  - Whether the entries are integers or strings, and their meaning.
-
-- pinmux takes a list of pin IDs and mux settings as required argument. The
-  specific bindings for the hardware defines:
-  - How pin IDs and mux settings are defined and assembled together in a single
-    integer or an array of integers.
-
-- bias-pull-up, -down and -pin-default take as optional argument on hardware
-  supporting it the pull strength in Ohm. bias-disable will disable the pull.
-
-- drive-strength takes as argument the target strength in mA.
-
-- drive-strength-microamp takes as argument the target strength in uA.
-
-- input-debounce takes the debounce time in usec as argument
-  or 0 to disable debouncing
-
-More in-depth documentation on these parameters can be found in
-<include/linux/pinctrl/pinconf-generic.h>
+See pincfg-node.yaml

Documentation/devicetree/bindings/pinctrl/pinmux-node.yaml

+# SPDX-License-Identifier: GPL-2.0-only
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pinctrl/pinmux-node.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Generic pin multiplexing node schema
+
+maintainers:
+  - Linus Walleij <linus.walleij@linaro.org>
+
+description: |
+  The contents of the pin configuration child nodes are defined by the binding
+  for the individual pin controller device. The pin configuration nodes need not
+  be direct children of the pin controller device; they may be grandchildren,
+  for example. Whether this is legal, and whether there is any interaction
+  between the child and intermediate parent nodes, is again defined entirely by
+  the binding for the individual pin controller device.
+
+  While not required to be used, there are 3 generic forms of pin muxing nodes
+  which pin controller devices can use.
+
+  pin multiplexing nodes:
+
+  Example:
+
+  state_0_node_a {
+    uart0 {
+      function = "uart0";
+      groups = "u0rxtx", "u0rtscts";
+    };
+  };
+  state_1_node_a {
+    spi0 {
+      function = "spi0";
+      groups = "spi0pins";
+    };
+  };
+  state_2_node_a {
+    function = "i2c0";
+    pins = "mfio29", "mfio30";
+  };
+
+  Optionally an alternative binding can be used if more suitable depending on the
+  pin controller hardware. For hardware where there is a large number of identical
+  pin controller instances, naming each pin and function can easily become
+  unmaintainable. This is especially the case if the same controller is used for
+  different pins and functions depending on the SoC revision and packaging.
+
+  For cases like this, the pin controller driver may use pinctrl-pin-array helper
+  binding with a hardware based index and a number of pin configuration values:
+
+  pincontroller {
+    ... /* Standard DT properties for the device itself elided */
+    #pinctrl-cells = <2>;
+
+    state_0_node_a {
+      pinctrl-pin-array = <
+        0 A_DELAY_PS(0) G_DELAY_PS(120)
+        4 A_DELAY_PS(0) G_DELAY_PS(360)
+        ...
+        >;
+    };
+    ...
+  };
+
+  Above #pinctrl-cells specifies the number of value cells in addition to the
+  index of the registers. This is similar to the interrupts-extended binding with
+  one exception. There is no need to specify the phandle for each entry as that
+  is already known as the defined pins are always children of the pin controller
+  node. Further having the phandle pointing to another pin controller would not
+  currently work as the pinctrl framework uses named modes to group pins for each
+  pin control device.
+
+  The index for pinctrl-pin-array must relate to the hardware for the pinctrl
+  registers, and must not be a virtual index of pin instances. The reason for
+  this is to avoid mapping of the index in the dts files and the pin controller
+  driver as it can change.
+
+  For hardware where pin multiplexing configurations have to be specified for
+  each single pin the number of required sub-nodes containing "pin" and
+  "function" properties can quickly escalate and become hard to write and
+  maintain.
+
+  For cases like this, the pin controller driver may use the pinmux helper
+  property, where the pin identifier is provided with mux configuration settings
+  in a pinmux group. A pinmux group consists of the pin identifier and mux
+  settings represented as a single integer or an array of integers.
+
+  The pinmux property accepts an array of pinmux groups, each of them describing
+  a single pin multiplexing configuration.
+
+  pincontroller {
+    state_0_node_a {
+      pinmux = <PINMUX_GROUP>, <PINMUX_GROUP>, ...;
+    };
+  };
+
+  Each individual pin controller driver bindings documentation shall specify
+  how pin IDs and pin multiplexing configuration are defined and assembled
+  together in a pinmux group.
+
+properties:
+  function:
+    $ref: /schemas/types.yaml#/definitions/string
+    description: The mux function to select
+
+  pins:
+    oneOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32-array
+      - $ref: /schemas/types.yaml#/definitions/string-array
+    description:
+      The list of pin identifiers that properties in the node apply to. The
+      specific binding for the hardware defines whether the entries are integers
+      or strings, and their meaning.
+
+  group:
+    $ref: /schemas/types.yaml#/definitions/string-array
+    description:
+      the group to apply the properties to, if the driver supports
+      configuration of whole groups rather than individual pins (either
+      this, "pins" or "pinmux" has to be specified)
+
+  pinmux:
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32-array
+    description:
+      The list of numeric pin ids and their mux settings that properties in the
+      node apply to (either this, "pins" or "groups" have to be specified)
+
+  pinctrl-pin-array:
+    $ref: /schemas/types.yaml#/definitions/uint32-array