gpiolib: Introduce gpio_device_get() and gpio_device_put()

Introduce gpio_device_get() and gpio_device_put() helpers
and convert existing users.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

drivers/gpio/gpiolib-cdev.c

@@ -321,7 +321,7 @@ static void linehandle_free(struct linehandle_state *lh)
 		if (lh->descs[i])
 			gpiod_free(lh->descs[i]);
 	kfree(lh->label);
-	put_device(&lh->gdev->dev);
+	gpio_device_put(lh->gdev);
 	kfree(lh);
 }
 
@@ -363,8 +363,7 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
 	lh = kzalloc(sizeof(*lh), GFP_KERNEL);
 	if (!lh)
 		return -ENOMEM;
-	lh->gdev = gdev;
+	lh->gdev = gpio_device_get(gdev);
-	get_device(&gdev->dev);
 
 	if (handlereq.consumer_label[0] != '\0') {
 		/* label is only initialized if consumer_label is set */
@@ -1576,7 +1575,7 @@ static void linereq_free(struct linereq *lr)
 	}
 	kfifo_free(&lr->events);
 	kfree(lr->label);
-	put_device(&lr->gdev->dev);
+	gpio_device_put(lr->gdev);
 	kfree(lr);
 }
 
@@ -1646,8 +1645,7 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip)
 	if (!lr)
 		return -ENOMEM;
 
-	lr->gdev = gdev;
+	lr->gdev = gpio_device_get(gdev);
-	get_device(&gdev->dev);
 
 	for (i = 0; i < ulr.num_lines; i++) {
 		lr->lines[i].req = lr;
@@ -1916,7 +1914,7 @@ static void lineevent_free(struct lineevent_state *le)
 	if (le->desc)
 		gpiod_free(le->desc);
 	kfree(le->label);
-	put_device(&le->gdev->dev);
+	gpio_device_put(le->gdev);
 	kfree(le);
 }
 
@@ -2094,8 +2092,7 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
 	le = kzalloc(sizeof(*le), GFP_KERNEL);
 	if (!le)
 		return -ENOMEM;
-	le->gdev = gdev;
+	le->gdev = gpio_device_get(gdev);
-	get_device(&gdev->dev);
 
 	if (eventreq.consumer_label[0] != '\0') {
 		/* label is only initialized if consumer_label is set */
@@ -2671,7 +2668,7 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
 
 	init_waitqueue_head(&cdev->wait);
 	INIT_KFIFO(cdev->events);
-	cdev->gdev = gdev;
+	cdev->gdev = gpio_device_get(gdev);
 
 	cdev->lineinfo_changed_nb.notifier_call = lineinfo_changed_notify;
 	ret = blocking_notifier_chain_register(&gdev->notifier,
@@ -2679,7 +2676,6 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
 	if (ret)
 		goto out_free_bitmap;
 
-	get_device(&gdev->dev);
 	file->private_data = cdev;
 
 	ret = nonseekable_open(inode, file);
@@ -2694,6 +2690,7 @@ out_unregister_notifier:
 	blocking_notifier_chain_unregister(&gdev->notifier,
 					   &cdev->lineinfo_changed_nb);
 out_free_bitmap:
+	gpio_device_put(gdev);
 	bitmap_free(cdev->watched_lines);
 out_free_cdev:
 	kfree(cdev);
@@ -2716,7 +2713,7 @@ static int gpio_chrdev_release(struct inode *inode, struct file *file)
 	bitmap_free(cdev->watched_lines);
 	blocking_notifier_chain_unregister(&gdev->notifier,
 					   &cdev->lineinfo_changed_nb);
-	put_device(&gdev->dev);
+	gpio_device_put(gdev);
 	kfree(cdev);
 
 	return 0;

drivers/gpio/gpiolib.c

@@ -882,7 +882,7 @@ err_free_gpiochip_mask:
 	gpiochip_free_valid_mask(gc);
 	if (gdev->dev.release) {
 		/* release() has been registered by gpiochip_setup_dev() */
-		put_device(&gdev->dev);
+		gpio_device_put(gdev);
 		goto err_print_message;
 	}
 err_remove_from_list:
@@ -972,7 +972,7 @@ void gpiochip_remove(struct gpio_chip *gc)
 	 */
 	gcdev_unregister(gdev);
 	up_write(&gdev->sem);
-	put_device(&gdev->dev);
+	gpio_device_put(gdev);
 }
 EXPORT_SYMBOL_GPL(gpiochip_remove);
 
@@ -2057,17 +2057,15 @@ static int validate_desc(const struct gpio_desc *desc, const char *func)
 int gpiod_request(struct gpio_desc *desc, const char *label)
 {
 	int ret = -EPROBE_DEFER;
-	struct gpio_device *gdev;
 
 	VALIDATE_DESC(desc);
-	gdev = desc->gdev;
 
-	if (try_module_get(gdev->owner)) {
+	if (try_module_get(desc->gdev->owner)) {
 		ret = gpiod_request_commit(desc, label);
 		if (ret)
-			module_put(gdev->owner);
+			module_put(desc->gdev->owner);
 		else
-			get_device(&gdev->dev);
+			gpio_device_get(desc->gdev);
 	}
 
 	if (ret)
@@ -2128,7 +2126,7 @@ void gpiod_free(struct gpio_desc *desc)
 {
 	if (desc && desc->gdev && gpiod_free_commit(desc)) {
 		module_put(desc->gdev->owner);
-		put_device(&desc->gdev->dev);
+		gpio_device_put(desc->gdev);
 	} else {
 		WARN_ON(extra_checks);
 	}

drivers/gpio/gpiolib.h

@@ -82,6 +82,16 @@ static inline struct gpio_device *to_gpio_device(struct device *dev)
 	return container_of(dev, struct gpio_device, dev);
 }
 
+static inline struct gpio_device *gpio_device_get(struct gpio_device *gdev)
+{
+	return to_gpio_device(get_device(&gdev->dev));
+}
+
+static inline void gpio_device_put(struct gpio_device *gdev)
+{
+	put_device(&gdev->dev);
+}
+
 /* gpio suffixes used for ACPI and device tree lookup */
 static __maybe_unused const char * const gpio_suffixes[] = { "gpios", "gpio" };