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>

1 files changed, 80 insertions, 81 deletions

diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index cbb1add43d5e..b890231debd8 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/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 @@ fail:
 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),
         }
 };