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backlight: Make backlight_class constant

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Since commit 43a7206b09 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the backlight_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20240305-class_cleanup-backlight-v1-1-c0e15cc25be1@marliere.net
Signed-off-by: Lee Jones <lee@kernel.org>
This commit is contained in:
Ricardo B. Marliere 2024-03-05 09:21:17 -03:00 committed by Lee Jones
parent e962f13b1e
commit cda12ba555
1 changed files with 16 additions and 13 deletions
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29
drivers/video/backlight/backlight.c
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@ -319,8 +319,6 @@ static ssize_t scale_show(struct device *dev,
} }
static DEVICE_ATTR_RO(scale); static DEVICE_ATTR_RO(scale);
static struct class *backlight_class;
#ifdef CONFIG_PM_SLEEP #ifdef CONFIG_PM_SLEEP
static int backlight_suspend(struct device *dev) static int backlight_suspend(struct device *dev)
{ {
@ -371,6 +369,12 @@ static struct attribute *bl_device_attrs[] = {
}; };
ATTRIBUTE_GROUPS(bl_device); ATTRIBUTE_GROUPS(bl_device);
static const struct class backlight_class = {
.name = "backlight",
.dev_groups = bl_device_groups,
.pm = &backlight_class_dev_pm_ops,
};
/** /**
* backlight_force_update - tell the backlight subsystem that hardware state * backlight_force_update - tell the backlight subsystem that hardware state
* has changed * has changed
@ -420,7 +424,7 @@ struct backlight_device *backlight_device_register(const char *name,
mutex_init(&new_bd->update_lock); mutex_init(&new_bd->update_lock);
mutex_init(&new_bd->ops_lock); mutex_init(&new_bd->ops_lock);
new_bd->dev.class = backlight_class; new_bd->dev.class = &backlight_class;
new_bd->dev.parent = parent; new_bd->dev.parent = parent;
new_bd->dev.release = bl_device_release; new_bd->dev.release = bl_device_release;
dev_set_name(&new_bd->dev, "%s", name); dev_set_name(&new_bd->dev, "%s", name);
@ -512,7 +516,7 @@ struct backlight_device *backlight_device_get_by_name(const char *name)
{ {
struct device *dev; struct device *dev;
dev = class_find_device_by_name(backlight_class, name); dev = class_find_device_by_name(&backlight_class, name);
return dev ? to_backlight_device(dev) : NULL; return dev ? to_backlight_device(dev) : NULL;
} }
@ -680,7 +684,7 @@ struct backlight_device *of_find_backlight_by_node(struct device_node *node)
{ {
struct device *dev; struct device *dev;
dev = class_find_device(backlight_class, NULL, node, of_parent_match); dev = class_find_device(&backlight_class, NULL, node, of_parent_match);
return dev ? to_backlight_device(dev) : NULL; return dev ? to_backlight_device(dev) : NULL;
} }
@ -748,20 +752,19 @@ EXPORT_SYMBOL(devm_of_find_backlight);
static void __exit backlight_class_exit(void) static void __exit backlight_class_exit(void)
{ {
class_destroy(backlight_class); class_unregister(&backlight_class);
} }
static int __init backlight_class_init(void) static int __init backlight_class_init(void)
{ {
backlight_class = class_create("backlight"); int ret;
if (IS_ERR(backlight_class)) {
pr_warn("Unable to create backlight class; errno = %ld\n", ret = class_register(&backlight_class);
PTR_ERR(backlight_class)); if (ret) {
return PTR_ERR(backlight_class); pr_warn("Unable to create backlight class; errno = %d\n", ret);
return ret;
} }
backlight_class->dev_groups = bl_device_groups;
backlight_class->pm = &backlight_class_dev_pm_ops;
INIT_LIST_HEAD(&backlight_dev_list); INIT_LIST_HEAD(&backlight_dev_list);
mutex_init(&backlight_dev_list_mutex); mutex_init(&backlight_dev_list_mutex);
BLOCKING_INIT_NOTIFIER_HEAD(&backlight_notifier); BLOCKING_INIT_NOTIFIER_HEAD(&backlight_notifier);