From: Thomas Zimmermann Date: Fri, 21 Mar 2025 09:54:01 +0000 (+0100) Subject: backlight: lcd: Replace fb events with a dedicated function call X-Git-Tag: v6.16-rc1~61^2~4 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bc70cc84f5a2ebfd7e7112e9b8837e0c7954fc65;p=thirdparty%2Fkernel%2Flinux.git backlight: lcd: Replace fb events with a dedicated function call Remove support for fb events from the lcd subsystem. Provide the helper lcd_notify_blank_all() instead. In fbdev, call lcd_notify_blank_all() to inform the lcd subsystem of changes to a display's blank state. Fbdev maintains a list of all installed notifiers. Instead of fbdev notifiers, maintain an internal list of lcd devices. v3: - export lcd_notify_mode_change_all() (kernel test robot) v2: - maintain global list of lcd devices - avoid IS_REACHABLE() in source file - use lock guards - initialize lcd list and list mutex Signed-off-by: Thomas Zimmermann Acked-by: Simona Vetter Reviewed-by: "Daniel Thompson (RISCstar)" Link: https://lore.kernel.org/r/20250321095517.313713-9-tzimmermann@suse.de Signed-off-by: Lee Jones --- diff --git a/drivers/video/backlight/lcd.c b/drivers/video/backlight/lcd.c index f57ff8bcc2fa5..affe5c52471a1 100644 --- a/drivers/video/backlight/lcd.c +++ b/drivers/video/backlight/lcd.c @@ -15,9 +15,11 @@ #include #include #include -#include #include +static DEFINE_MUTEX(lcd_dev_list_mutex); +static LIST_HEAD(lcd_dev_list); + static void lcd_notify_blank(struct lcd_device *ld, struct device *display_dev, int power) { @@ -31,6 +33,17 @@ static void lcd_notify_blank(struct lcd_device *ld, struct device *display_dev, ld->ops->set_power(ld, power); } +void lcd_notify_blank_all(struct device *display_dev, int power) +{ + struct lcd_device *ld; + + guard(mutex)(&lcd_dev_list_mutex); + + list_for_each_entry(ld, &lcd_dev_list, entry) + lcd_notify_blank(ld, display_dev, power); +} +EXPORT_SYMBOL(lcd_notify_blank_all); + static void lcd_notify_mode_change(struct lcd_device *ld, struct device *display_dev, unsigned int width, unsigned int height) { @@ -44,75 +57,17 @@ static void lcd_notify_mode_change(struct lcd_device *ld, struct device *display ld->ops->set_mode(ld, width, height); } -#if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \ - defined(CONFIG_LCD_CLASS_DEVICE_MODULE)) -static int to_lcd_power(int fb_blank) +void lcd_notify_mode_change_all(struct device *display_dev, + unsigned int width, unsigned int height) { - switch (fb_blank) { - case FB_BLANK_UNBLANK: - return LCD_POWER_ON; - /* deprecated; TODO: should become 'off' */ - case FB_BLANK_NORMAL: - return LCD_POWER_REDUCED; - case FB_BLANK_VSYNC_SUSPEND: - return LCD_POWER_REDUCED_VSYNC_SUSPEND; - /* 'off' */ - case FB_BLANK_HSYNC_SUSPEND: - case FB_BLANK_POWERDOWN: - default: - return LCD_POWER_OFF; - } -} + struct lcd_device *ld; -/* This callback gets called when something important happens inside a - * framebuffer driver. We're looking if that important event is blanking, - * and if it is, we're switching lcd power as well ... - */ -static int fb_notifier_callback(struct notifier_block *self, - unsigned long event, void *data) -{ - struct lcd_device *ld = container_of(self, struct lcd_device, fb_notif); - struct fb_event *evdata = data; - struct fb_info *info = evdata->info; - struct lcd_device *fb_lcd = fb_lcd_device(info); - - if (fb_lcd && fb_lcd != ld) - return 0; - - if (event == FB_EVENT_BLANK) { - int power = to_lcd_power(*(int *)evdata->data); - - lcd_notify_blank(ld, info->device, power); - } else { - const struct fb_videomode *videomode = evdata->data; - - lcd_notify_mode_change(ld, info->device, videomode->xres, videomode->yres); - } + guard(mutex)(&lcd_dev_list_mutex); - return 0; + list_for_each_entry(ld, &lcd_dev_list, entry) + lcd_notify_mode_change(ld, display_dev, width, height); } - -static int lcd_register_fb(struct lcd_device *ld) -{ - memset(&ld->fb_notif, 0, sizeof(ld->fb_notif)); - ld->fb_notif.notifier_call = fb_notifier_callback; - return fb_register_client(&ld->fb_notif); -} - -static void lcd_unregister_fb(struct lcd_device *ld) -{ - fb_unregister_client(&ld->fb_notif); -} -#else -static int lcd_register_fb(struct lcd_device *ld) -{ - return 0; -} - -static inline void lcd_unregister_fb(struct lcd_device *ld) -{ -} -#endif /* CONFIG_FB */ +EXPORT_SYMBOL(lcd_notify_mode_change_all); static ssize_t lcd_power_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -263,11 +218,8 @@ struct lcd_device *lcd_device_register(const char *name, struct device *parent, return ERR_PTR(rc); } - rc = lcd_register_fb(new_ld); - if (rc) { - device_unregister(&new_ld->dev); - return ERR_PTR(rc); - } + guard(mutex)(&lcd_dev_list_mutex); + list_add(&new_ld->entry, &lcd_dev_list); return new_ld; } @@ -284,10 +236,12 @@ void lcd_device_unregister(struct lcd_device *ld) if (!ld) return; + guard(mutex)(&lcd_dev_list_mutex); + list_del(&ld->entry); + mutex_lock(&ld->ops_lock); ld->ops = NULL; mutex_unlock(&ld->ops_lock); - lcd_unregister_fb(ld); device_unregister(&ld->dev); } diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index c931f270ac343..001662c606d72 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -15,6 +15,7 @@ #include #include #include +#include #include