pinctrl: xway: fix gpio-hog related boot issues

This patch is based on commit a86caa9b ("pinctrl: msm: fix gpio-hog
related boot issues").

It fixes the issue that the gpio ranges needs to be defined before
gpiochip_add().

Therefore, we also have to swap the order of registering the pinctrl
driver and registering the gpio chip.

You also have to add the "gpio-ranges" property to the pinctrl device
node to get it finally working.
Signed-off-by: Martin Schiller <ms@dev.tdt.de>
Acked-by: John Crispin <john@phrozen.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-xway.c

@@ -1746,14 +1746,6 @@ static int pinmux_xway_probe(struct platform_device *pdev)
 	}
 	xway_pctrl_desc.pins = xway_info.pads;
 
-	/* register the gpio chip */
-	xway_chip.parent = &pdev->dev;
-	ret = devm_gpiochip_add_data(&pdev->dev, &xway_chip, NULL);
-	if (ret) {
-		dev_err(&pdev->dev, "Failed to register gpio chip\n");
-		return ret;
-	}
-
 	/* setup the data needed by pinctrl */
 	xway_pctrl_desc.name	= dev_name(&pdev->dev);
 	xway_pctrl_desc.npins	= xway_chip.ngpio;
@@ -1775,10 +1767,33 @@ static int pinmux_xway_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	/* finish with registering the gpio range in pinctrl */
-	xway_gpio_range.npins = xway_chip.ngpio;
-	xway_gpio_range.base = xway_chip.base;
-	pinctrl_add_gpio_range(xway_info.pctrl, &xway_gpio_range);
+	/* register the gpio chip */
+	xway_chip.parent = &pdev->dev;
+	xway_chip.owner = THIS_MODULE;
+	xway_chip.of_node = pdev->dev.of_node;
+	ret = devm_gpiochip_add_data(&pdev->dev, &xway_chip, NULL);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to register gpio chip\n");
+		return ret;
+	}
+
+	/*
+	 * For DeviceTree-supported systems, the gpio core checks the
+	 * pinctrl's device node for the "gpio-ranges" property.
+	 * If it is present, it takes care of adding the pin ranges
+	 * for the driver. In this case the driver can skip ahead.
+	 *
+	 * In order to remain compatible with older, existing DeviceTree
+	 * files which don't set the "gpio-ranges" property or systems that
+	 * utilize ACPI the driver has to call gpiochip_add_pin_range().
+	 */
+	if (!of_property_read_bool(pdev->dev.of_node, "gpio-ranges")) {
+		/* finish with registering the gpio range in pinctrl */
+		xway_gpio_range.npins = xway_chip.ngpio;
+		xway_gpio_range.base = xway_chip.base;
+		pinctrl_add_gpio_range(xway_info.pctrl, &xway_gpio_range);
+	}
+
 	dev_info(&pdev->dev, "Init done\n");
 	return 0;
 }