gpiolib: provide and use gpiod_line_state_notify()

Wrap the calls to blocking_notifier_call_chain() for the line state
notifier with a helper that allows us to use fewer lines of code and
simpler syntax.

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

Author: Bartosz Golaszewski

drivers/gpio/gpiolib-cdev.c

@@ -230,9 +230,7 @@ static long linehandle_set_config(struct linehandle_state *lh,
 				return ret;
 		}
 
-		blocking_notifier_call_chain(&desc->gdev->line_state_notifier,
-					     GPIO_V2_LINE_CHANGED_CONFIG,
-					     desc);
+		gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
 	}
 	return 0;
 }
@@ -414,8 +412,7 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
 				goto out_free_lh;
 		}
 
-		blocking_notifier_call_chain(&desc->gdev->line_state_notifier,
-					     GPIO_V2_LINE_CHANGED_REQUESTED, desc);
+		gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED);
 
 		dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
 			offset);
@@ -1420,9 +1417,7 @@ static long linereq_set_config_unlocked(struct linereq *lr,
 
 		WRITE_ONCE(line->edflags, edflags);
 
-		blocking_notifier_call_chain(&desc->gdev->line_state_notifier,
-					     GPIO_V2_LINE_CHANGED_CONFIG,
-					     desc);
+		gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_CONFIG);
 	}
 	return 0;
 }
@@ -1737,8 +1732,7 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip)
 
 		lr->lines[i].edflags = edflags;
 
-		blocking_notifier_call_chain(&desc->gdev->line_state_notifier,
-					     GPIO_V2_LINE_CHANGED_REQUESTED, desc);
+		gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED);
 
 		dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
 			offset);
@@ -2156,8 +2150,7 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
 	if (ret)
 		goto out_free_le;
 
-	blocking_notifier_call_chain(&desc->gdev->line_state_notifier,
-				     GPIO_V2_LINE_CHANGED_REQUESTED, desc);
+	gpiod_line_state_notify(desc, GPIO_V2_LINE_CHANGED_REQUESTED);
 
 	irq = gpiod_to_irq(desc);
 	if (irq <= 0) {

drivers/gpio/gpiolib.c

@@ -2178,8 +2178,7 @@ static bool gpiod_free_commit(struct gpio_desc *desc)
 	}
 
 	spin_unlock_irqrestore(&gpio_lock, flags);
-	blocking_notifier_call_chain(&desc->gdev->line_state_notifier,
-				     GPIOLINE_CHANGED_RELEASED, desc);
+	gpiod_line_state_notify(desc, GPIOLINE_CHANGED_RELEASED);
 
 	return ret;
 }
@@ -3741,6 +3740,12 @@ int gpiod_set_array_value_cansleep(unsigned int array_size,
 }
 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
 
+void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action)
+{
+	blocking_notifier_call_chain(&desc->gdev->line_state_notifier,
+				     action, desc);
+}
+
 /**
  * gpiod_add_lookup_table() - register GPIO device consumers
  * @table: table of consumers to register
@@ -4008,8 +4013,7 @@ static struct gpio_desc *gpiod_find_and_request(struct device *consumer,
 		return ERR_PTR(ret);
 	}
 
-	blocking_notifier_call_chain(&desc->gdev->line_state_notifier,
-				     GPIOLINE_CHANGED_REQUESTED, desc);
+	gpiod_line_state_notify(desc, GPIOLINE_CHANGED_REQUESTED);
 
 	return desc;
 }

drivers/gpio/gpiolib.h

@@ -147,6 +147,7 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep,
 extern spinlock_t gpio_lock;
 extern struct list_head gpio_devices;
 
+void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action);
 
 /**
  * struct gpio_desc - Opaque descriptor for a GPIO