gpiolib: utilize new cdev_device_add helper function

Replace the open coded registration of the cdev and dev with the
new device_add_cdev() helper. The helper replaces a common pattern by
taking the proper reference against the parent device and adding both
the cdev and the device.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/gpio/gpiolib.c

@@ -1035,18 +1035,14 @@ static int gpiochip_setup_dev(struct gpio_device *gdev)
 
 	cdev_init(&gdev->chrdev, &gpio_fileops);
 	gdev->chrdev.owner = THIS_MODULE;
-	gdev->chrdev.kobj.parent = &gdev->dev.kobj;
 	gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id);
-	status = cdev_add(&gdev->chrdev, gdev->dev.devt, 1);
-	if (status < 0)
-		chip_warn(gdev->chip, "failed to add char device %d:%d\n",
-			  MAJOR(gpio_devt), gdev->id);
-	else
+
+	status = cdev_device_add(&gdev->chrdev, &gdev->dev);
+	if (status)
+		return status;
+
 	chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n",
 		 MAJOR(gpio_devt), gdev->id);
-	status = device_add(&gdev->dev);
-	if (status)
-		goto err_remove_chardev;
 
 	status = gpiochip_sysfs_register(gdev);
 	if (status)
@@ -1061,9 +1057,7 @@ static int gpiochip_setup_dev(struct gpio_device *gdev)
 	return 0;
 
 err_remove_device:
-	device_del(&gdev->dev);
-err_remove_chardev:
-	cdev_del(&gdev->chrdev);
+	cdev_device_del(&gdev->chrdev, &gdev->dev);
 	return status;
 }
 
@@ -1347,8 +1341,7 @@ void gpiochip_remove(struct gpio_chip *chip)
 	 * be removed, else it will be dangling until the last user is
 	 * gone.
 	 */
-	cdev_del(&gdev->chrdev);
-	device_del(&gdev->dev);
+	cdev_device_del(&gdev->chrdev, &gdev->dev);
 	put_device(&gdev->dev);
 }
 EXPORT_SYMBOL_GPL(gpiochip_remove);