In backlight class, update_status() callback function is mostly used to change
backlight brightness. When platform enter the dimming state, it is usually used.
But, I think dimming state can be defined variety of method including brightness.
So, it is need to differentiated node from brightness node.
In set_dimming() callback function, developers can define variety dimming functions.
Signed-off-by: Donghwa Lee <dh09.lee@xxxxxxxxxxx>
Signed-off-by: Inki Dae <inki.dae@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
drivers/video/backlight/backlight.c | 37 +++++++++++++++++++++++++++++++++++
include/linux/backlight.h | 9 ++++++++
2 files changed, 46 insertions(+), 0 deletions(-)
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index bf5b1ec..44a77e4 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -101,6 +101,43 @@ static void backlight_generate_event(struct backlight_device *bd,
sysfs_notify(&bd->dev.kobj, NULL, "actual_brightness");
}
+static ssize_t backlight_store_dimming(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ int rc;
+ struct backlight_device *bd = to_backlight_device(dev);
+ unsigned long dimming;
+
+ rc = strict_strtoul(buf, 0, &dimming);
+ if (rc)
+ return rc;
+
+ if (dimming < 0)
+ rc = -EINVAL;
+ else {
+ pr_debug("set dimming mode\n");
+
+ if (dimming)
+ bd->props.dimming = true;
+ else
+ bd->props.dimming = false;
+
+ backlight_set_dimming(bd);
+
+ rc = count;
+ }
+
+ return rc;
+}
+
+static ssize_t backlight_show_dimming(struct device *dev,
+ struct device_attribute *attr,char *buf)
+{
+ struct backlight_device *bd = to_backlight_device(dev);
+
+ return sprintf(buf, "%d\n", bd->props.dimming);
+}
+
static ssize_t backlight_show_power(struct device *dev,
struct device_attribute *attr, char *buf)
{
diff --git a/include/linux/backlight.h b/include/linux/backlight.h
index 5ffc6dd..823717e 100644
--- a/include/linux/backlight.h
+++ b/include/linux/backlight.h
@@ -55,10 +55,13 @@ struct backlight_ops {
/* Check if given framebuffer device is the one bound to this backlight;
return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */
int (*check_fb)(struct backlight_device *, struct fb_info *);
+ /* Notify the backlight driver to enter the dimming state */
+ int (*set_dimming)(struct backlight_device *);
};
/* This structure defines all the properties of a backlight */
struct backlight_properties {
+ bool dimming;
/* Current User requested brightness (0 - max_brightness) */
int brightness;
/* Maximal value for brightness (read-only) */
@@ -111,6 +114,12 @@ static inline void backlight_update_status(struct backlight_device *bd)
mutex_unlock(&bd->update_lock);
}
+static inline void backlight_set_dimming(struct backlight_device *bd)
+{
+ if (bd->ops && bd->ops->set_dimming)
+ bd->ops->set_dimming(bd);
+}
+
extern struct backlight_device *backlight_device_register(const char *name,
struct device *dev, void *devdata, const struct backlight_ops *ops,
const struct backlight_properties *props);
--
1.7.4.1
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