hte: handle nvidia,gpio-controller property

The dt binding adds nvidia,gpio-controller property from Tegra234 SoC
onwards to simplify code handling gpio chip search. The gpio chip search
is needed for the AON GPIO GTE instances to map the hardware timestamp
GPIO request (coming from the GPIO framework) to the tegra HTE
providers. The patch also adds new gpio chip match function to match
from the fwnode instead of the gpio controller label. The addition
of the property does not break ABI for the existing Tegra194 code.
Signed-off-by: Dipen Patel <dipenp@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

drivers/hte/hte-tegra194.c

@@ -679,6 +679,11 @@ static int tegra_get_gpiochip_from_name(struct gpio_chip *chip, void *data)
 	return !strcmp(chip->label, data);
 }
 
+static int tegra_gpiochip_match(struct gpio_chip *chip, void *data)
+{
+	return chip->fwnode == of_node_to_fwnode(data);
+}
+
 static int tegra_hte_probe(struct platform_device *pdev)
 {
 	int ret;
@@ -687,6 +692,7 @@ static int tegra_hte_probe(struct platform_device *pdev)
 	struct device *dev;
 	struct tegra_hte_soc *hte_dev;
 	struct hte_chip *gc;
+	struct device_node *gpio_ctrl;
 
 	dev = &pdev->dev;
 
@@ -754,15 +760,23 @@ static int tegra_hte_probe(struct platform_device *pdev)
 		gc->match_from_linedata = tegra_hte_match_from_linedata;
 
 		if (of_device_is_compatible(dev->of_node,
-					    "nvidia,tegra194-gte-aon"))
+					    "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;
+		} else {
+			gpio_ctrl = of_parse_phandle(dev->of_node,
+						     "nvidia,gpio-controller",
+						     0);
+			if (!gpio_ctrl) {
+				dev_err(dev,
+					"gpio controller node not found\n");
+				return -ENODEV;
+			}
+
+			hte_dev->c = gpiochip_find(gpio_ctrl,
+						   tegra_gpiochip_match);
+			of_node_put(gpio_ctrl);
+		}
 
 		if (!hte_dev->c)
 			return dev_err_probe(dev, -EPROBE_DEFER,