Commit a067419b authored by Bartosz Golaszewski's avatar Bartosz Golaszewski
Browse files

gpiolib: add a second blocking notifier to struct gpio_device 



Add a new blocking notifier to struct gpio_device and use it to notify
subscribers about the GPIO device being unregistered from the device
model.

Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Reviewed-by: default avatarKent Gibson <warthog618@gmail.com>
parent e82bbd67

drivers/gpio/gpiolib-cdev.c

+1 −0
Original line number Diff line number Diff line
@@ -2748,4 +2748,5 @@ int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt) 
void gpiolib_cdev_unregister(struct gpio_device *gdev)

{

	cdev_device_del(&gdev->chrdev, &gdev->dev);

	blocking_notifier_call_chain(&gdev->device_notifier, 0, NULL);

}

drivers/gpio/gpiolib.c

+1 −0
Original line number Diff line number Diff line
@@ -848,6 +848,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, 
	spin_unlock_irqrestore(&gpio_lock, flags);



	BLOCKING_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier);

	BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier);

	init_rwsem(&gdev->sem);



#ifdef CONFIG_PINCTRL

drivers/gpio/gpiolib.h

+3 −0
Original line number Diff line number Diff line
@@ -41,6 +41,8 @@ 
 * @list: links gpio_device:s together for traversal

 * @line_state_notifier: used to notify subscribers about lines being

 *                       requested, released or reconfigured

 * @device_notifier: used to notify character device wait queues about the GPIO

 *                   device being unregistered

 * @sem: protects the structure from a NULL-pointer dereference of @chip by

 *       user-space operations when the device gets unregistered during

 *       a hot-unplug event
@@ -65,6 +67,7 @@ struct gpio_device { 
	void			*data;

	struct list_head        list;

	struct blocking_notifier_head line_state_notifier;

	struct blocking_notifier_head device_notifier;

	struct rw_semaphore	sem;



#ifdef CONFIG_PINCTRL