gpiolib: provide gpiod_remove_hogs()

Currently all users of gpiod_add_hogs() call it only once at system init so there never was any need for a mechanism allowing to remove them. Now the upcoming gpio-sim will need to tear down chips with hogged lines so provide a function that allows to remove hogs. Signed-off-by: Bartosz Golaszewski <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> Acked-by: Linus Walleij <[email protected]>
sparnez · Dec 17, 2021 · dd61b29 · dd61b29
1 parent ab39d69
commit dd61b29
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diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
@@ -3557,6 +3557,17 @@ void gpiod_add_hogs(struct gpiod_hog *hogs)
 }
 EXPORT_SYMBOL_GPL(gpiod_add_hogs);
 
+void gpiod_remove_hogs(struct gpiod_hog *hogs)
+{
+	struct gpiod_hog *hog;
+
+	mutex_lock(&gpio_machine_hogs_mutex);
+	for (hog = &hogs[0]; hog->chip_label; hog++)
+		list_del(&hog->list);
+	mutex_unlock(&gpio_machine_hogs_mutex);
+}
+EXPORT_SYMBOL_GPL(gpiod_remove_hogs);
+
 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
 {
 	const char *dev_id = dev ? dev_name(dev) : NULL;

diff --git a/include/linux/gpio/machine.h b/include/linux/gpio/machine.h
@@ -100,6 +100,7 @@ void gpiod_add_lookup_table(struct gpiod_lookup_table *table);
 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n);
 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table);
 void gpiod_add_hogs(struct gpiod_hog *hogs);
+void gpiod_remove_hogs(struct gpiod_hog *hogs);
 #else /* ! CONFIG_GPIOLIB */
 static inline
 void gpiod_add_lookup_table(struct gpiod_lookup_table *table) {}
@@ -108,6 +109,7 @@ void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n) {}
 static inline
 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) {}
 static inline void gpiod_add_hogs(struct gpiod_hog *hogs) {}
+static inline void gpiod_remove_hogs(struct gpiod_hog *hogs) {}
 #endif /* CONFIG_GPIOLIB */
 
 #endif /* __LINUX_GPIO_MACHINE_H */