diff mbox series

[2/2] video: backlight: lcd: make lcd_class constant

Message ID 20240305-class_cleanup-backlight-v1-2-c0e15cc25be1@marliere.net
State New
Headers show
Series video: backlight: constify struct class usage | expand

Commit Message

Ricardo B. Marliere March 5, 2024, 12:21 p.m. UTC 
Since commit 43a7206b0963 ("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 lcd_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>
---
 drivers/video/backlight/lcd.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

Comments

Daniel Thompson March 25, 2024, 10:51 a.m. UTC | #1 
On Tue, Mar 05, 2024 at 09:21:18AM -0300, Ricardo B. Marliere wrote:
> Since commit 43a7206b0963 ("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 lcd_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>


Daniel.
diff mbox series

Patch

diff --git a/drivers/video/backlight/lcd.c b/drivers/video/backlight/lcd.c
index 77c5cb2a44e2..ba4771cbd781 100644
--- a/drivers/video/backlight/lcd.c
+++ b/drivers/video/backlight/lcd.c
@@ -159,8 +159,6 @@  static ssize_t max_contrast_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(max_contrast);
 
-static struct class *lcd_class;
-
 static void lcd_device_release(struct device *dev)
 {
 	struct lcd_device *ld = to_lcd_device(dev);
@@ -175,6 +173,11 @@  static struct attribute *lcd_device_attrs[] = {
 };
 ATTRIBUTE_GROUPS(lcd_device);
 
+static const struct class lcd_class = {
+	.name = "lcd",
+	.dev_groups = lcd_device_groups,
+};
+
 /**
  * lcd_device_register - register a new object of lcd_device class.
  * @name: the name of the new object(must be the same as the name of the
@@ -202,7 +205,7 @@  struct lcd_device *lcd_device_register(const char *name, struct device *parent,
 	mutex_init(&new_ld->ops_lock);
 	mutex_init(&new_ld->update_lock);
 
-	new_ld->dev.class = lcd_class;
+	new_ld->dev.class = &lcd_class;
 	new_ld->dev.parent = parent;
 	new_ld->dev.release = lcd_device_release;
 	dev_set_name(&new_ld->dev, "%s", name);
@@ -318,19 +321,19 @@  EXPORT_SYMBOL(devm_lcd_device_unregister);
 
 static void __exit lcd_class_exit(void)
 {
-	class_destroy(lcd_class);
+	class_unregister(&lcd_class);
 }
 
 static int __init lcd_class_init(void)
 {
-	lcd_class = class_create("lcd");
-	if (IS_ERR(lcd_class)) {
-		pr_warn("Unable to create backlight class; errno = %ld\n",
-			PTR_ERR(lcd_class));
-		return PTR_ERR(lcd_class);
+	int ret;
+
+	ret = class_register(&lcd_class);
+	if (ret) {
+		pr_warn("Unable to create backlight class; errno = %d\n", ret);
+		return ret;
 	}
 
-	lcd_class->dev_groups = lcd_device_groups;
 	return 0;
 }