From: Bartosz Golaszewski Date: Thu, 17 Aug 2023 11:59:05 +0000 (+0200) Subject: gpiolib: add a second blocking notifier to struct gpio_device X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=a067419ba77da830939852758702388f0fba09a1;p=users%2Fjedix%2Flinux-maple.git 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: Bartosz Golaszewski Reviewed-by: Linus Walleij Reviewed-by: Kent Gibson --- diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index 91bdd3b928b5..fec446510028 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -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); } diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 38640df1d798..8f74e0bb2a5c 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -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 diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index 11a5e02f317d..e860ed434bc2 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -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