Framebuffer drivers for devices with dedicated backlight are supposed
to set struct fb_info.bl_dev to the backlight's respective device. Use
the value to match backlight and framebuffer in the backlight core code.
The code first tests against struct backlight_ops.check_ops. If this
test succeeds, it performs the test against fbdev. So backlight drivers
can override the later test as before.
Fbdev's backlight support depends on CONFIG_FB_BACKLIGHT. To avoid
ifdef in the code, the new helper fb_bl_device() returns the backlight
device, or NULL if the config option has been disabled. The test in
the backlight code will then do nothing.
v3:
* hide ifdef in fb_bl_device() (Lee)
* no if-else blocks (Andy)
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Reviewed-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
Reviewed-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
---
drivers/video/backlight/backlight.c | 8 ++++++--
drivers/video/fbdev/core/fb_backlight.c | 5 +++++
include/linux/fb.h | 9 +++++++++
3 files changed, 20 insertions(+), 2 deletions(-)
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 86e1cdc8e3697..4f7973c6fcc79 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -98,7 +98,9 @@ static int fb_notifier_callback(struct notifier_block *self,
{
struct backlight_device *bd;
struct fb_event *evdata = data;
- int node = evdata->info->node;
+ struct fb_info *info = evdata->info;
+ struct backlight_device *fb_bd = fb_bl_device(info);
+ int node = info->node;
int fb_blank = 0;
/* If we aren't interested in this event, skip it immediately ... */
@@ -110,7 +112,9 @@ static int fb_notifier_callback(struct notifier_block *self,
if (!bd->ops)
goto out;
- if (bd->ops->check_fb && !bd->ops->check_fb(bd, evdata->info))
+ if (bd->ops->check_fb && !bd->ops->check_fb(bd, info))
+ goto out;
+ if (fb_bd && fb_bd != bd)
goto out;
fb_blank = *(int *)evdata->data;
diff --git a/drivers/video/fbdev/core/fb_backlight.c b/drivers/video/fbdev/core/fb_backlight.c
index e2d3b3adc870f..d3470a90042ea 100644
--- a/drivers/video/fbdev/core/fb_backlight.c
+++ b/drivers/video/fbdev/core/fb_backlight.c
@@ -30,4 +30,9 @@ void fb_bl_default_curve(struct fb_info *fb_info, u8 off, u8 min, u8 max)
mutex_unlock(&fb_info->bl_curve_mutex);
}
EXPORT_SYMBOL_GPL(fb_bl_default_curve);
+
+struct backlight_device *fb_bl_device(struct fb_info *info)
+{
+ return info->bl_dev;
+}
#endif
diff --git a/include/linux/fb.h b/include/linux/fb.h
index 708e6a177b1be..1dce640308b5e 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -732,6 +732,15 @@ extern struct fb_info *framebuffer_alloc(size_t size, struct device *dev);
extern void framebuffer_release(struct fb_info *info);
extern void fb_bl_default_curve(struct fb_info *fb_info, u8 off, u8 min, u8 max);
+#if IS_ENABLED(CONFIG_FB_BACKLIGHT)
+struct backlight_device *fb_bl_device(struct fb_info *info);
+#else
+struct backlight_device *fb_bl_device(struct fb_info *info)
+{
+ return NULL;
+}
+#endif
+
/* fbmon.c */
#define FB_MAXTIMINGS 0
#define FB_VSYNCTIMINGS 1
--
2.44.0
