dt-bindings: pinctrl: mt8195: add wrapping node of pin configurations

On mt8195, the pinctrl node has pinctrl groups to group pin
configurations by users' need. In each pinctrl group, it has
subnode(s) to list pins needed and pin configurations. By supporting
multiple subnodes, we can configure different pin characteristics
(driving/pull-up/pull-down/etc.) in a pinctrl group.

Update pinctrl-mt8195.yaml to add subnode in pinctrl groups and an
example to illustrate the usage.
Signed-off-by: Tinghan Shen <tinghan.shen@mediatek.com>
Acked-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211220121825.6446-4-tinghan.shen@mediatek.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/pinctrl-mt8195.yaml

@@ -55,10 +55,15 @@ properties:
       Identifying i2c pins pull up/down type which is RSEL. It can support
       RSEL define or si unit value(ohm) to set different resistance.
 
-#PIN CONFIGURATION NODES
+# PIN CONFIGURATION NODES
 patternProperties:
   '-pins$':
     type: object
+    additionalProperties: false
+    patternProperties:
+      '^pins':
+        type: object
+        additionalProperties: false
         description: |
           A pinctrl node should contain at least one subnodes representing the
           pinctrl groups available on the machine. Each subnode will list the
@@ -68,12 +73,16 @@ patternProperties:
           An example of using macro:
           pincontroller {
             /* GPIO0 set as multifunction GPIO0 */
-        gpio_pin {
+            gpio-pins {
+              pins {
                 pinmux = <PINMUX_GPIO0__FUNC_GPIO0>;
+              }
             };
             /* GPIO8 set as multifunction SDA0 */
-        i2c0_pin {
+            i2c0-pins {
+              pins {
                 pinmux = <PINMUX_GPIO8__FUNC_SDA0>;
+              }
             };
           };
         $ref: "pinmux-node.yaml"
@@ -82,8 +91,9 @@ patternProperties:
           pinmux:
             description: |
               Integer array, represents gpio pin number and mux setting.
-          Supported pin number and mux varies for different SoCs, and are defined
-          as macros in dt-bindings/pinctrl/<soc>-pinfunc.h directly.
+              Supported pin number and mux varies for different SoCs, and are
+              defined as macros in dt-bindings/pinctrl/<soc>-pinfunc.h
+              directly.
 
           drive-strength:
             enum: [2, 4, 6, 8, 10, 12, 14, 16]
@@ -94,14 +104,17 @@ patternProperties:
               and resistance value.
               For pull down type is PUPD/R0/R1 type, it can add R1R0 define to
               set different resistance. It can support "MTK_PUPD_SET_R1R0_00" &
-          "MTK_PUPD_SET_R1R0_01" & "MTK_PUPD_SET_R1R0_10" & "MTK_PUPD_SET_R1R0_11"
-          define in mt8195.
-          For pull down type is RSEL, it can add RSEL define & resistance value(ohm)
-          to set different resistance by identifying property "mediatek,rsel_resistance_in_si_unit".
+              "MTK_PUPD_SET_R1R0_01" & "MTK_PUPD_SET_R1R0_10" &
+              "MTK_PUPD_SET_R1R0_11" define in mt8195.
+              For pull down type is RSEL, it can add RSEL define & resistance
+              value(ohm) to set different resistance by identifying property
+              "mediatek,rsel_resistance_in_si_unit".
               It can support "MTK_PULL_SET_RSEL_000" & "MTK_PULL_SET_RSEL_001"
-          & "MTK_PULL_SET_RSEL_010" & "MTK_PULL_SET_RSEL_011" & "MTK_PULL_SET_RSEL_100"
-          & "MTK_PULL_SET_RSEL_101" & "MTK_PULL_SET_RSEL_110" & "MTK_PULL_SET_RSEL_111"
-          define in mt8195. It can also support resistance value(ohm) "75000" & "5000" in mt8195.
+              & "MTK_PULL_SET_RSEL_010" & "MTK_PULL_SET_RSEL_011"
+              & "MTK_PULL_SET_RSEL_100" & "MTK_PULL_SET_RSEL_101"
+              & "MTK_PULL_SET_RSEL_110" & "MTK_PULL_SET_RSEL_111"
+              define in mt8195. It can also support resistance value(ohm)
+              "75000" & "5000" in mt8195.
               oneOf:
                 - enum: [100, 101, 102, 103]
                 - description: mt8195 pull down PUPD/R0/R1 type define value.
@@ -113,8 +126,10 @@ patternProperties:
               An example of using RSEL define:
               pincontroller {
                 i2c0_pin {
+                  pins {
                     pinmux = <PINMUX_GPIO8__FUNC_SDA0>;
                     bias-pull-down = <MTK_PULL_SET_RSEL_001>;
+                  }
                 };
               };
               An example of using si unit resistance value(ohm):
@@ -123,8 +138,10 @@ patternProperties:
               }
               pincontroller {
                 i2c0_pin {
+                  pins {
                     pinmux = <PINMUX_GPIO8__FUNC_SDA0>;
                     bias-pull-down = <75000>;
+                  }
                 };
               };
 
@@ -134,15 +151,18 @@ patternProperties:
               and resistance value.
               For pull up type is PUPD/R0/R1 type, it can add R1R0 define to
               set different resistance. It can support "MTK_PUPD_SET_R1R0_00" &
-          "MTK_PUPD_SET_R1R0_01" & "MTK_PUPD_SET_R1R0_10" & "MTK_PUPD_SET_R1R0_11"
-          define in mt8195.
-          For pull up type is RSEL, it can add RSEL define & resistance value(ohm)
-          to set different resistance by identifying property "mediatek,rsel_resistance_in_si_unit".
+              "MTK_PUPD_SET_R1R0_01" & "MTK_PUPD_SET_R1R0_10" &
+              "MTK_PUPD_SET_R1R0_11" define in mt8195.
+              For pull up type is RSEL, it can add RSEL define & resistance
+              value(ohm) to set different resistance by identifying property
+              "mediatek,rsel_resistance_in_si_unit".
               It can support "MTK_PULL_SET_RSEL_000" & "MTK_PULL_SET_RSEL_001"
-          & "MTK_PULL_SET_RSEL_010" & "MTK_PULL_SET_RSEL_011" & "MTK_PULL_SET_RSEL_100"
-          & "MTK_PULL_SET_RSEL_101" & "MTK_PULL_SET_RSEL_110" & "MTK_PULL_SET_RSEL_111"
+              & "MTK_PULL_SET_RSEL_010" & "MTK_PULL_SET_RSEL_011"
+              & "MTK_PULL_SET_RSEL_100" & "MTK_PULL_SET_RSEL_101"
+              & "MTK_PULL_SET_RSEL_110" & "MTK_PULL_SET_RSEL_111"
               define in mt8195. It can also support resistance value(ohm)
-          "1000" & "1500" & "2000" & "3000" & "4000" & "5000" & "10000" & "75000" in mt8195.
+              "1000" & "1500" & "2000" & "3000" & "4000" & "5000" & "10000" &
+              "75000" in mt8195.
               oneOf:
                 - enum: [100, 101, 102, 103]
                 - description: mt8195 pull up PUPD/R0/R1 type define value.
@@ -152,9 +172,11 @@ patternProperties:
                 - description: mt8195 pull up RSEL type si unit value(ohm).
               An example of using RSEL define:
               pincontroller {
-            i2c0_pin {
+                i2c0-pins {
+                  pins {
                     pinmux = <PINMUX_GPIO8__FUNC_SDA0>;
                     bias-pull-up = <MTK_PULL_SET_RSEL_001>;
+                  }
                 };
               };
               An example of using si unit resistance value(ohm):
@@ -162,9 +184,11 @@ patternProperties:
                 mediatek,rsel_resistance_in_si_unit;
               }
               pincontroller {
-            i2c0_pin {
+                i2c0-pins {
+                  pins {
                     pinmux = <PINMUX_GPIO8__FUNC_SDA0>;
                     bias-pull-up = <1000>;
+                  }
                 };
               };
 
@@ -185,8 +209,6 @@ patternProperties:
         required:
           - pinmux
 
-    additionalProperties: false
-
 allOf:
   - $ref: "pinctrl.yaml#"
 
@@ -206,6 +228,7 @@ examples:
   - |
     #include <dt-bindings/pinctrl/mt8195-pinfunc.h>
     #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #
     pio: pinctrl@10005000 {
       compatible = "mediatek,mt8195-pinctrl";
       reg = <0x10005000 0x1000>,
@@ -227,7 +250,22 @@ examples:
       #interrupt-cells = <2>;
 
       pio-pins {
+        pins {
           pinmux = <PINMUX_GPIO0__FUNC_GPIO0>;
           output-low;
         };
       };
+
+      spi0-pins {
+        pins-spi {
+          pinmux = <PINMUX_GPIO132__FUNC_SPIM0_CSB>,
+                   <PINMUX_GPIO134__FUNC_SPIM0_MO>,
+                   <PINMUX_GPIO133__FUNC_SPIM0_CLK>;
+          bias-disable;
+        };
+        pins-spi-mi {
+          pinmux = <PINMUX_GPIO135__FUNC_SPIM0_MI>;
+          bias-pull-down;
+        };
+      };
+    };