Input: gpio_keys - switch to using generic device properties

Make use of the device property API in this driver so that both OF based
systems and ACPI based systems can use this driver.

Suggested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Suggested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/keyboard/gpio_keys.c

@@ -28,8 +28,6 @@
 #include <linux/gpio.h>
 #include <linux/gpio/consumer.h>
 #include <linux/of.h>
-#include <linux/of_platform.h>
-#include <linux/of_gpio.h>
 #include <linux/of_irq.h>
 #include <linux/spinlock.h>
 
@@ -468,7 +466,8 @@ static void gpio_keys_quiesce_key(void *data)
 static int gpio_keys_setup_key(struct platform_device *pdev,
 				struct input_dev *input,
 				struct gpio_button_data *bdata,
-				const struct gpio_keys_button *button)
+				const struct gpio_keys_button *button,
+				struct fwnode_handle *child)
 {
 	const char *desc = button->desc ? button->desc : "gpio_keys";
 	struct device *dev = &pdev->dev;
@@ -481,11 +480,28 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
 	bdata->button = button;
 	spin_lock_init(&bdata->lock);
 
-	/*
-	 * Legacy GPIO number, so request the GPIO here and
-	 * convert it to descriptor.
-	 */
-	if (gpio_is_valid(button->gpio)) {
+	if (child) {
+		bdata->gpiod = devm_get_gpiod_from_child(dev, NULL, child);
+		if (IS_ERR(bdata->gpiod)) {
+			error = PTR_ERR(bdata->gpiod);
+			if (error == -ENOENT) {
+				/*
+				 * GPIO is optional, we may be dealing with
+				 * purely interrupt-driven setup.
+				 */
+				bdata->gpiod = NULL;
+			} else {
+				if (error != -EPROBE_DEFER)
+					dev_err(dev, "failed to get gpio: %d\n",
+						error);
+				return error;
+			}
+		}
+	} else if (gpio_is_valid(button->gpio)) {
+		/*
+		 * Legacy GPIO number, so request the GPIO here and
+		 * convert it to descriptor.
+		 */
 		unsigned flags = GPIOF_IN;
 
 		if (button->active_low)
@@ -502,7 +518,9 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
 		bdata->gpiod = gpio_to_desc(button->gpio);
 		if (!bdata->gpiod)
 			return -EINVAL;
+	}
 
+	if (bdata->gpiod) {
 		if (button->debounce_interval) {
 			error = gpiod_set_debounce(bdata->gpiod,
 					button->debounce_interval * 1000);
@@ -533,9 +551,10 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
 
 	} else {
 		if (!button->irq) {
-			dev_err(dev, "No IRQ specified\n");
+			dev_err(dev, "Found button without gpio or irq\n");
 			return -EINVAL;
 		}
+
 		bdata->irq = button->irq;
 
 		if (button->type && button->type != EV_KEY) {
@@ -627,24 +646,18 @@ static void gpio_keys_close(struct input_dev *input)
  * Handlers for alternative sources of platform_data
  */
 
-#ifdef CONFIG_OF
 /*
- * Translate OpenFirmware node properties into platform_data
+ * Translate properties into platform_data
  */
 static struct gpio_keys_platform_data *
 gpio_keys_get_devtree_pdata(struct device *dev)
 {
-	struct device_node *node, *pp;
 	struct gpio_keys_platform_data *pdata;
 	struct gpio_keys_button *button;
-	int error;
+	struct fwnode_handle *child;
 	int nbuttons;
 
-	node = dev->of_node;
-	if (!node)
-		return ERR_PTR(-ENODEV);
-
-	nbuttons = of_get_available_child_count(node);
+	nbuttons = device_get_child_node_count(dev);
 	if (nbuttons == 0)
 		return ERR_PTR(-ENODEV);
 
@@ -659,64 +672,43 @@ gpio_keys_get_devtree_pdata(struct device *dev)
 	pdata->buttons = button;
 	pdata->nbuttons = nbuttons;
 
-	pdata->rep = !!of_get_property(node, "autorepeat", NULL);
+	pdata->rep = device_property_read_bool(dev, "autorepeat");
 
-	of_property_read_string(node, "label", &pdata->name);
+	device_property_read_string(dev, "label", &pdata->name);
 
-	for_each_available_child_of_node(node, pp) {
-		enum of_gpio_flags flags;
+	device_for_each_child_node(dev, child) {
+		if (is_of_node(child))
+			button->irq =
+				irq_of_parse_and_map(to_of_node(child), 0);
 
-		button->gpio = of_get_gpio_flags(pp, 0, &flags);
-		if (button->gpio < 0) {
-			error = button->gpio;
-			if (error != -ENOENT) {
-				if (error != -EPROBE_DEFER)
-					dev_err(dev,
-						"Failed to get gpio flags, error: %d\n",
-						error);
-				of_node_put(pp);
-				return ERR_PTR(error);
-			}
-		} else {
-			button->active_low = flags & OF_GPIO_ACTIVE_LOW;
-		}
-
-		button->irq = irq_of_parse_and_map(pp, 0);
-
-		if (!gpio_is_valid(button->gpio) && !button->irq) {
-			dev_err(dev, "Found button without gpios or irqs\n");
-			of_node_put(pp);
-			return ERR_PTR(-EINVAL);
-		}
-
-		if (of_property_read_u32(pp, "linux,code", &button->code)) {
-			dev_err(dev, "Button without keycode: 0x%x\n",
-				button->gpio);
-			of_node_put(pp);
+		if (fwnode_property_read_u32(child, "linux,code",
+					     &button->code)) {
+			dev_err(dev, "Button without keycode\n");
+			fwnode_handle_put(child);
 			return ERR_PTR(-EINVAL);
 		}
 
-		button->desc = of_get_property(pp, "label", NULL);
+		fwnode_property_read_string(child, "label", &button->desc);
 
-		if (of_property_read_u32(pp, "linux,input-type", &button->type))
+		if (fwnode_property_read_u32(child, "linux,input-type",
+					     &button->type))
 			button->type = EV_KEY;
 
-		button->wakeup = of_property_read_bool(pp, "wakeup-source") ||
-				 /* legacy name */
-				 of_property_read_bool(pp, "gpio-key,wakeup");
+		button->wakeup =
+			fwnode_property_read_bool(child, "wakeup-source") ||
+			/* legacy name */
+			fwnode_property_read_bool(child, "gpio-key,wakeup");
 
-		button->can_disable = !!of_get_property(pp, "linux,can-disable", NULL);
+		button->can_disable =
+			fwnode_property_read_bool(child, "linux,can-disable");
 
-		if (of_property_read_u32(pp, "debounce-interval",
+		if (fwnode_property_read_u32(child, "debounce-interval",
 					 &button->debounce_interval))
 			button->debounce_interval = 5;
 
 		button++;
 	}
 
-	if (pdata->nbuttons == 0)
-		return ERR_PTR(-EINVAL);
-
 	return pdata;
 }
 
@@ -726,20 +718,11 @@ static const struct of_device_id gpio_keys_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
 
-#else
-
-static inline struct gpio_keys_platform_data *
-gpio_keys_get_devtree_pdata(struct device *dev)
-{
-	return ERR_PTR(-ENODEV);
-}
-
-#endif
-
 static int gpio_keys_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
+	struct fwnode_handle *child = NULL;
 	struct gpio_keys_drvdata *ddata;
 	struct input_dev *input;
 	size_t size;
@@ -792,14 +775,28 @@ static int gpio_keys_probe(struct platform_device *pdev)
 		const struct gpio_keys_button *button = &pdata->buttons[i];
 		struct gpio_button_data *bdata = &ddata->data[i];
 
-		error = gpio_keys_setup_key(pdev, input, bdata, button);
-		if (error)
+		if (!dev_get_platdata(dev)) {
+			child = device_get_next_child_node(&pdev->dev, child);
+			if (!child) {
+				dev_err(&pdev->dev,
+					"missing child device node for entry %d\n",
+					i);
+				return -EINVAL;
+			}
+		}
+
+		error = gpio_keys_setup_key(pdev, input, bdata, button, child);
+		if (error) {
+			fwnode_handle_put(child);
 			return error;
+		}
 
 		if (button->wakeup)
 			wakeup = 1;
 	}
 
+	fwnode_handle_put(child);
+
 	error = sysfs_create_group(&pdev->dev.kobj, &gpio_keys_attr_group);
 	if (error) {
 		dev_err(dev, "Unable to export keys/switches, error: %d\n",
@@ -889,7 +886,7 @@ static struct platform_driver gpio_keys_device_driver = {
 	.driver		= {
 		.name	= "gpio-keys",
 		.pm	= &gpio_keys_pm_ops,
-		.of_match_table = of_match_ptr(gpio_keys_of_match),
+		.of_match_table = gpio_keys_of_match,
 	}
 };