gpio: mpc8xxx: Convert to platform device interface.

This way we do not need to transverse the device tree manually.

Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-mpc8xxx.c

@@ -15,6 +15,7 @@
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/of_irq.h>
+#include <linux/of_platform.h>
 #include <linux/gpio.h>
 #include <linux/slab.h>
 #include <linux/irq.h>
@@ -342,8 +343,9 @@ static struct of_device_id mpc8xxx_gpio_ids[] __initdata = {
 	{}
 };
 
-static void __init mpc8xxx_add_controller(struct device_node *np)
+static int mpc8xxx_probe(struct platform_device *pdev)
 {
+	struct device_node *np = pdev->dev.of_node;
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc;
 	struct of_mm_gpio_chip *mm_gc;
 	struct gpio_chip *gc;
@@ -351,11 +353,9 @@ static void __init mpc8xxx_add_controller(struct device_node *np)
 	unsigned hwirq;
 	int ret;
 
-	mpc8xxx_gc = kzalloc(sizeof(*mpc8xxx_gc), GFP_KERNEL);
-	if (!mpc8xxx_gc) {
-		ret = -ENOMEM;
-		goto err;
-	}
+	mpc8xxx_gc = devm_kzalloc(&pdev->dev, sizeof(*mpc8xxx_gc), GFP_KERNEL);
+	if (!mpc8xxx_gc)
+		return -ENOMEM;
 
 	spin_lock_init(&mpc8xxx_gc->lock);
 
@@ -375,16 +375,16 @@ static void __init mpc8xxx_add_controller(struct device_node *np)
 
 	ret = of_mm_gpiochip_add(np, mm_gc);
 	if (ret)
-		goto err;
+		return ret;
 
 	hwirq = irq_of_parse_and_map(np, 0);
 	if (hwirq == NO_IRQ)
-		goto skip_irq;
+		return 0;
 
 	mpc8xxx_gc->irq = irq_domain_add_linear(np, MPC8XXX_GPIO_PINS,
 					&mpc8xxx_gpio_irq_ops, mpc8xxx_gc);
 	if (!mpc8xxx_gc->irq)
-		goto skip_irq;
+		return 0;
 
 	id = of_match_node(mpc8xxx_gpio_ids, np);
 	if (id)
@@ -397,24 +397,20 @@ static void __init mpc8xxx_add_controller(struct device_node *np)
 	irq_set_handler_data(hwirq, mpc8xxx_gc);
 	irq_set_chained_handler(hwirq, mpc8xxx_gpio_irq_cascade);
 
-skip_irq:
-	return;
-
-err:
-	pr_err("%s: registration failed with status %d\n",
-	       np->full_name, ret);
-	kfree(mpc8xxx_gc);
-
-	return;
-}
-
-static int __init mpc8xxx_add_gpiochips(void)
-{
-	struct device_node *np;
-
-	for_each_matching_node(np, mpc8xxx_gpio_ids)
-		mpc8xxx_add_controller(np);
-
 	return 0;
 }
-arch_initcall(mpc8xxx_add_gpiochips);
+
+static struct platform_driver mpc8xxx_plat_driver = {
+	.probe		= mpc8xxx_probe,
+	.driver		= {
+		.name = "gpio-mpc8xxx",
+		.of_match_table	= mpc8xxx_gpio_ids,
+	},
+};
+
+static int __init mpc8xxx_init(void)
+{
+	return platform_driver_register(&mpc8xxx_plat_driver);
+}
+
+arch_initcall(mpc8xxx_init);