Revert "dt-bindings: pinctrl: bcm4708-pinmux: rework binding to use syscon"

This reverts commit 2ae80900f2.

My rework was unneeded & wrong. It replaced a clear & correct "reg"
property usage with a custom "offset" one.

Back then I didn't understand how to properly handle CRU block binding.
I heard / read about syscon and tried to use it in a totally invalid
way. That change also missed Rob's review (obviously).

Northstar's pin controller is a simple consistent hardware block that
can be cleanly mapped using a 0x24 long reg space.

Since the rework commit there wasn't any follow up modifying in-kernel
DTS files to use the new binding. Broadcom also isn't known to use that
bugged binding. There is close to zero chance this revert may actually
cause problems / regressions.

This commit is a simple revert. Example binding may (should) be updated
/ cleaned up but that can be handled separately.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211008205938.29925-1-zajec5@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/mfd/brcm,cru.yaml

@@ -32,13 +32,13 @@ properties:
   "#size-cells":
     const: 1
 
-  pinctrl:
-    $ref: ../pinctrl/brcm,ns-pinmux.yaml
-
 patternProperties:
   '^clock-controller@[a-f0-9]+$':
     $ref: ../clock/brcm,iproc-clocks.yaml
 
+  '^pin-controller@[a-f0-9]+$':
+    $ref: ../pinctrl/brcm,ns-pinmux.yaml
+
   '^thermal@[a-f0-9]+$':
     $ref: ../thermal/brcm,ns-thermal.yaml
 
@@ -73,9 +73,10 @@ examples:
                                  "iprocfast", "sata1", "sata2";
         };
 
-        pinctrl {
+        pin-controller@1c0 {
             compatible = "brcm,bcm4708-pinmux";
-            offset = <0x1c0>;
+            reg = <0x1c0 0x24>;
+            reg-names = "cru_gpio_control";
         };
 
         thermal@2c0 {

Documentation/devicetree/bindings/pinctrl/brcm,ns-pinmux.yaml

@@ -17,9 +17,6 @@ description:
 
   A list of pins varies across chipsets so few bindings are available.
 
-  Node of the pinmux must be nested in the CRU (Central Resource Unit) "syscon"
-  node.
-
 properties:
   compatible:
     enum:
@@ -27,10 +24,11 @@ properties:
       - brcm,bcm4709-pinmux
       - brcm,bcm53012-pinmux
 
-  offset:
-    description: offset of pin registers in the CRU block
+  reg:
     maxItems: 1
-    $ref: /schemas/types.yaml#/definitions/uint32-array
+
+  reg-names:
+    const: cru_gpio_control
 
 patternProperties:
   '-pins$':
@@ -72,19 +70,24 @@ allOf:
                         uart1_grp ]
 
 required:
-  - offset
+  - reg
+  - reg-names
 
 additionalProperties: false
 
 examples:
   - |
     cru@1800c100 {
-        compatible = "syscon", "simple-mfd";
+        compatible = "simple-bus";
         reg = <0x1800c100 0x1a4>;
+        ranges;
+        #address-cells = <1>;
+        #size-cells = <1>;
 
-        pinctrl {
+        pin-controller@1c0 {
             compatible = "brcm,bcm4708-pinmux";
-            offset = <0xc0>;
+            reg = <0x1c0 0x24>;
+            reg-names = "cru_gpio_control";
 
             spi-pins {
                 function = "spi";