[PATCH V4 04/10] dt-bindings: timestamp: Add nvidia,gpio-controller

[Dipen Patel <dipenp@nvidia.com>]

Introducing nvidia,gpio-controller property from Tegra234 SoCs onwards.
This is done to help below case.

Without this property code would look like:
if (of_device_is_compatible(dev->of_node, "nvidia,tegra194-gte-aon"))
	hte_dev->c = gpiochip_find("tegra194-gpio-aon",
				   tegra_get_gpiochip_from_name);
else if (of_device_is_compatible(dev->of_node, "nvidia,tegra234-gte-aon"))
	hte_dev->c = gpiochip_find("tegra234-gpio-aon",
				   tegra_get_gpiochip_from_name);
else
	return -ENODEV;

This means for every future addition of the compatible string, if else
condition statements have to be expanded.

With the property:
gpio_ctrl = of_parse_phandle(dev->of_node, "nvidia,gpio-controller", 0);
....
hte_dev->c = gpiochip_find(gpio_ctrl, tegra_get_gpiochip_from_of_node);

This simplifies the code significantly. The introdunction of this
property/binding does not break existing Tegra194 provider driver.

Signed-off-by: Dipen Patel <dipenp@nvidia.com>
---
 .../timestamp/nvidia,tegra194-hte.yaml        | 31 +++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/timestamp/nvidia,tegra194-hte.yaml b/Documentation/devicetree/bindings/timestamp/nvidia,tegra194-hte.yaml
index eafc33e9ae2e..841273a3d8ae 100644
--- a/Documentation/devicetree/bindings/timestamp/nvidia,tegra194-hte.yaml
+++ b/Documentation/devicetree/bindings/timestamp/nvidia,tegra194-hte.yaml
@@ -51,6 +51,12 @@ properties:
       LIC instance has 11 slices and Tegra234 LIC has 17 slices.
     enum: [3, 11, 17]
 
+  nvidia,gpio-controller:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      The phandle to AON gpio controller instance. This is required to handle
+      namespace conversion between GPIO and GTE.
+
   '#timestamp-cells':
     description:
       This represents number of line id arguments as specified by the
@@ -65,22 +71,43 @@ required:
   - interrupts
   - "#timestamp-cells"
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - nvidia,tegra234-gte-aon
+    then:
+      required:
+        - nvidia,gpio-controller
+
 additionalProperties: false
 
 examples:
   - |
     tegra_hte_aon: timestamp@c1e0000 {
               compatible = "nvidia,tegra194-gte-aon";
-              reg = <0xc1e0000 0x10000>;
+              reg = <0x0 0xc1e0000 0x0 0x10000>;
+              interrupts = <0 13 0x4>;
+              nvidia,int-threshold = <1>;
+              #timestamp-cells = <1>;
+    };
+
+  - |
+    tegra234_hte_aon: timestamp@c1e0000 {
+              compatible = "nvidia,tegra234-gte-aon";
+              reg = <0x0 0xc1e0000 0x0 0x10000>;
               interrupts = <0 13 0x4>;
               nvidia,int-threshold = <1>;
+              nvidia,gpio-controller = <&gpio_aon>;
               #timestamp-cells = <1>;
     };
 
   - |
     tegra_hte_lic: timestamp@3aa0000 {
               compatible = "nvidia,tegra194-gte-lic";
-              reg = <0x3aa0000 0x10000>;
+              reg = <0x0 0x3aa0000 0x0 0x10000>;
               interrupts = <0 11 0x4>;
               nvidia,int-threshold = <1>;
               #timestamp-cells = <1>;
-- 
2.17.1