[PATCH v2 03/24] backlight: Add get/set operations for brightness properties

[Sam Ravnborg <sam@ravnborg.org>]

Add get and set operations to incapsualte access to backlight brightness.

One easy win is that the get/set operations can be used when backlight
is not included in the configuration, resulting in simpler code with
less ifdef's and thus more readable code.

The backlight_enable_brightness() update the brightness and enable
the backlight.

The backlight_update_brightness() force the brightness update and
typical usage is to set brightness after registering a backlight device.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jingoo Han <jingoohan1@gmail.com>
---
 include/linux/backlight.h | 74 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/include/linux/backlight.h b/include/linux/backlight.h
index 93a47a6cf681..e390444bed13 100644
--- a/include/linux/backlight.h
+++ b/include/linux/backlight.h
@@ -492,6 +492,80 @@ static inline int backlight_get_brightness(const struct backlight_device *bd)
 		return bd->props.brightness;
 }
 
+/**
+ * backlight_get_actual_brightness - Returns the actual brightness
+ *
+ * On failure a negative error code is returned.
+ */
+static inline int backlight_get_actual_brightness(struct backlight_device *bd)
+{
+	if (bd && bd->ops && bd->ops->get_brightness)
+		return bd->ops->get_brightness(bd);
+	else
+		return -EINVAL;
+}
+
+/**
+ * backlight_get_max_brightness - Returns maximum brightness
+ *
+ * This helper operation is preferred over direct access to
+ * &backlight_properties.max_brightness
+ *
+ * Returns 0 if backlight_device is NULL
+ */
+
+static inline int backlight_get_max_brightness(const struct backlight_device *bd)
+{
+	if (bd)
+		return bd->props.max_brightness;
+	else
+		return 0;
+}
+
+/**
+ * backlight_set_brightness - Set the brightness to the specified value
+ *
+ * This helper operation is preferred over direct assignment to
+ * &backlight_properties.brightness.
+ *
+ * If backlight_device is NULL then silently exit.
+ */
+static inline void backlight_set_brightness(struct backlight_device *bd, int brightness)
+{
+	if (bd)
+		bd->props.brightness = brightness;
+}
+
+/**
+ * backlight_update_brightness - Update the brightness to the specified value
+ *
+ * Update brightness and force an update.
+ *
+ * If backlight_device is NULL then silently exit.
+ */
+static inline void backlight_update_brightness(struct backlight_device *bd, int brightness)
+{
+	if (bd) {
+		bd->props.brightness = brightness;
+		backlight_update_status(bd);
+	}
+}
+
+/**
+ * backlight_enable_brightness - Enable backligt using specified brightness
+ *
+ * Enable brightness using the specified brightness.
+ *
+ * If backlight_device is NULL then silently exit.
+ */
+static inline void backlight_enable_brightness(struct backlight_device *bd, int brightness)
+{
+	if (bd) {
+		bd->props.brightness = brightness;
+		backlight_enable(bd);
+	}
+}
+
 struct backlight_device *
 backlight_device_register(const char *name, struct device *dev, void *devdata,
 			  const struct backlight_ops *ops,
-- 
2.25.1

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