Input: gpio_keys - clean up device tree parser

- fix sizeof in memset;
- clean up dt properties extraction;
- use for_each_chil_of_node macro;
- use of_get_child_count();
- use of_match_ptr macro.
Signed-off-by: Alexandre Pereira da Silva <aletes.xgr@gmail.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
[Fabio Estevam <fabio.estevam@freescale.com>: fix fix NULL pointer
dereference for dt case - pdata->buttons wasn't initialized]
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/keyboard/gpio_keys.c

@@ -43,11 +43,9 @@ struct gpio_button_data {
 };
 
 struct gpio_keys_drvdata {
+	const struct gpio_keys_platform_data *pdata;
 	struct input_dev *input;
 	struct mutex disable_lock;
-	unsigned int n_buttons;
-	int (*enable)(struct device *dev);
-	void (*disable)(struct device *dev);
 	struct gpio_button_data data[0];
 };
 
@@ -171,7 +169,7 @@ static ssize_t gpio_keys_attr_show_helper(struct gpio_keys_drvdata *ddata,
 	if (!bits)
 		return -ENOMEM;
 
-	for (i = 0; i < ddata->n_buttons; i++) {
+	for (i = 0; i < ddata->pdata->nbuttons; i++) {
 		struct gpio_button_data *bdata = &ddata->data[i];
 
 		if (bdata->button->type != type)
@@ -219,7 +217,7 @@ static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
 		goto out;
 
 	/* First validate */
-	for (i = 0; i < ddata->n_buttons; i++) {
+	for (i = 0; i < ddata->pdata->nbuttons; i++) {
 		struct gpio_button_data *bdata = &ddata->data[i];
 
 		if (bdata->button->type != type)
@@ -234,7 +232,7 @@ static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
 
 	mutex_lock(&ddata->disable_lock);
 
-	for (i = 0; i < ddata->n_buttons; i++) {
+	for (i = 0; i < ddata->pdata->nbuttons; i++) {
 		struct gpio_button_data *bdata = &ddata->data[i];
 
 		if (bdata->button->type != type)
@@ -523,56 +521,64 @@ static int __devinit gpio_keys_setup_key(struct platform_device *pdev,
 static int gpio_keys_open(struct input_dev *input)
 {
 	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
+	const struct gpio_keys_platform_data *pdata = ddata->pdata;
 
-	return ddata->enable ? ddata->enable(input->dev.parent) : 0;
+	return pdata->enable ? pdata->enable(input->dev.parent) : 0;
 }
 
 static void gpio_keys_close(struct input_dev *input)
 {
 	struct gpio_keys_drvdata *ddata = input_get_drvdata(input);
+	const struct gpio_keys_platform_data *pdata = ddata->pdata;
 
-	if (ddata->disable)
-		ddata->disable(input->dev.parent);
+	if (pdata->disable)
+		pdata->disable(input->dev.parent);
 }
 
 /*
  * Handlers for alternative sources of platform_data
  */
+
 #ifdef CONFIG_OF
 /*
  * Translate OpenFirmware node properties into platform_data
  */
-static int gpio_keys_get_devtree_pdata(struct device *dev,
-			    struct gpio_keys_platform_data *pdata)
+static struct gpio_keys_platform_data * __devinit
+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;
+	int nbuttons;
 	int i;
-	struct gpio_keys_button *buttons;
-	u32 reg;
 
 	node = dev->of_node;
-	if (node == NULL)
-		return -ENODEV;
-
-	memset(pdata, 0, sizeof *pdata);
+	if (!node) {
+		error = -ENODEV;
+		goto err_out;
+	}
 
-	pdata->rep = !!of_get_property(node, "autorepeat", NULL);
+	nbuttons = of_get_child_count(node);
+	if (nbuttons == 0) {
+		error = -ENODEV;
+		goto err_out;
+	}
 
-	/* First count the subnodes */
-	pp = NULL;
-	while ((pp = of_get_next_child(node, pp)))
-		pdata->nbuttons++;
+	pdata = kzalloc(sizeof(*pdata) + nbuttons * (sizeof *button),
+			GFP_KERNEL);
+	if (!pdata) {
+		error = -ENOMEM;
+		goto err_out;
+	}
 
-	if (pdata->nbuttons == 0)
-		return -ENODEV;
+	pdata->buttons = (struct gpio_keys_button *)(pdata + 1);
+	pdata->nbuttons = nbuttons;
 
-	buttons = kzalloc(pdata->nbuttons * (sizeof *buttons), GFP_KERNEL);
-	if (!buttons)
-		return -ENOMEM;
+	pdata->rep = !!of_get_property(node, "autorepeat", NULL);
 
-	pp = NULL;
 	i = 0;
-	while ((pp = of_get_next_child(node, pp))) {
+	for_each_child_of_node(node, pp) {
 		enum of_gpio_flags flags;
 
 		if (!of_find_property(pp, "gpios", NULL)) {
@@ -580,39 +586,42 @@ static int gpio_keys_get_devtree_pdata(struct device *dev,
 			dev_warn(dev, "Found button without gpios\n");
 			continue;
 		}
-		buttons[i].gpio = of_get_gpio_flags(pp, 0, &flags);
-		buttons[i].active_low = flags & OF_GPIO_ACTIVE_LOW;
 
-		if (of_property_read_u32(pp, "linux,code", &reg)) {
-			dev_err(dev, "Button without keycode: 0x%x\n", buttons[i].gpio);
-			goto out_fail;
-		}
-		buttons[i].code = reg;
+		button = &pdata->buttons[i++];
 
-		buttons[i].desc = of_get_property(pp, "label", NULL);
+		button->gpio = of_get_gpio_flags(pp, 0, &flags);
+		button->active_low = flags & OF_GPIO_ACTIVE_LOW;
 
-		if (of_property_read_u32(pp, "linux,input-type", &reg) == 0)
-			buttons[i].type = reg;
-		else
-			buttons[i].type = EV_KEY;
+		if (of_property_read_u32(pp, "linux,code", &button->code)) {
+			dev_err(dev, "Button without keycode: 0x%x\n",
+				button->gpio);
+			error = -EINVAL;
+			goto err_free_pdata;
+		}
 
-		buttons[i].wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
+		button->desc = of_get_property(pp, "label", NULL);
 
-		if (of_property_read_u32(pp, "debounce-interval", &reg) == 0)
-			buttons[i].debounce_interval = reg;
-		else
-			buttons[i].debounce_interval = 5;
+		if (of_property_read_u32(pp, "linux,input-type", &button->type))
+			button->type = EV_KEY;
+
+		button->wakeup = !!of_get_property(pp, "gpio-key,wakeup", NULL);
 
-		i++;
+		if (of_property_read_u32(pp, "debounce-interval",
+					 &button->debounce_interval))
+			button->debounce_interval = 5;
 	}
 
-	pdata->buttons = buttons;
+	if (pdata->nbuttons == 0) {
+		error = -EINVAL;
+		goto err_free_pdata;
+	}
 
-	return 0;
+	return pdata;
 
-out_fail:
-	kfree(buttons);
-	return -ENODEV;
+err_free_pdata:
+	kfree(pdata);
+err_out:
+	return ERR_PTR(error);
 }
 
 static struct of_device_id gpio_keys_of_match[] = {
@@ -623,14 +632,12 @@ MODULE_DEVICE_TABLE(of, gpio_keys_of_match);
 
 #else
 
-static int gpio_keys_get_devtree_pdata(struct device *dev,
-			    struct gpio_keys_platform_data *altp)
+static inline struct gpio_keys_platform_data *
+gpio_keys_get_devtree_pdata(struct device *dev)
 {
-	return -ENODEV;
+	return ERR_PTR(-ENODEV);
 }
 
-#define gpio_keys_of_match NULL
-
 #endif
 
 static void gpio_remove_key(struct gpio_button_data *bdata)
@@ -645,19 +652,17 @@ static void gpio_remove_key(struct gpio_button_data *bdata)
 
 static int __devinit gpio_keys_probe(struct platform_device *pdev)
 {
-	const struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
-	struct gpio_keys_drvdata *ddata;
 	struct device *dev = &pdev->dev;
-	struct gpio_keys_platform_data alt_pdata;
+	const struct gpio_keys_platform_data *pdata = dev_get_platdata(dev);
+	struct gpio_keys_drvdata *ddata;
 	struct input_dev *input;
 	int i, error;
 	int wakeup = 0;
 
 	if (!pdata) {
-		error = gpio_keys_get_devtree_pdata(dev, &alt_pdata);
-		if (error)
-			return error;
-		pdata = &alt_pdata;
+		pdata = gpio_keys_get_devtree_pdata(dev);
+		if (IS_ERR(pdata))
+			return PTR_ERR(pdata);
 	}
 
 	ddata = kzalloc(sizeof(struct gpio_keys_drvdata) +
@@ -670,10 +675,8 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
 		goto fail1;
 	}
 
+	ddata->pdata = pdata;
 	ddata->input = input;
-	ddata->n_buttons = pdata->nbuttons;
-	ddata->enable = pdata->enable;
-	ddata->disable = pdata->disable;
 	mutex_init(&ddata->disable_lock);
 
 	platform_set_drvdata(pdev, ddata);
@@ -742,9 +745,9 @@ static int __devinit gpio_keys_probe(struct platform_device *pdev)
  fail1:
 	input_free_device(input);
 	kfree(ddata);
-	/* If we have no platform_data, we allocated buttons dynamically. */
-	if (!pdev->dev.platform_data)
-		kfree(pdata->buttons);
+	/* If we have no platform data, we allocated pdata dynamically. */
+	if (!dev_get_platdata(&pdev->dev))
+		kfree(pdata);
 
 	return error;
 }
@@ -759,18 +762,14 @@ static int __devexit gpio_keys_remove(struct platform_device *pdev)
 
 	device_init_wakeup(&pdev->dev, 0);
 
-	for (i = 0; i < ddata->n_buttons; i++)
+	for (i = 0; i < ddata->pdata->nbuttons; i++)
 		gpio_remove_key(&ddata->data[i]);
 
 	input_unregister_device(input);
 
-	/*
-	 * If we had no platform_data, we allocated buttons dynamically, and
-	 * must free them here. ddata->data[0].button is the pointer to the
-	 * beginning of the allocated array.
-	 */
-	if (!pdev->dev.platform_data)
-		kfree(ddata->data[0].button);
+	/* If we have no platform data, we allocated pdata dynamically. */
+	if (!dev_get_platdata(&pdev->dev))
+		kfree(ddata->pdata);
 
 	kfree(ddata);
 
@@ -784,7 +783,7 @@ static int gpio_keys_suspend(struct device *dev)
 	int i;
 
 	if (device_may_wakeup(dev)) {
-		for (i = 0; i < ddata->n_buttons; i++) {
+		for (i = 0; i < ddata->pdata->nbuttons; i++) {
 			struct gpio_button_data *bdata = &ddata->data[i];
 			if (bdata->button->wakeup)
 				enable_irq_wake(bdata->irq);
@@ -799,7 +798,7 @@ static int gpio_keys_resume(struct device *dev)
 	struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
 	int i;
 
-	for (i = 0; i < ddata->n_buttons; i++) {
+	for (i = 0; i < ddata->pdata->nbuttons; i++) {
 		struct gpio_button_data *bdata = &ddata->data[i];
 		if (bdata->button->wakeup && device_may_wakeup(dev))
 			disable_irq_wake(bdata->irq);
@@ -822,7 +821,7 @@ static struct platform_driver gpio_keys_device_driver = {
 		.name	= "gpio-keys",
 		.owner	= THIS_MODULE,
 		.pm	= &gpio_keys_pm_ops,
-		.of_match_table = gpio_keys_of_match,
+		.of_match_table = of_match_ptr(gpio_keys_of_match),
 	}
 };