+/*
+ * backlight
+ */
+static int ideapad_backlight_get_brightness(struct backlight_device *blightdev)
+{
+ unsigned long now;
+
+ if (read_ec_data(ideapad_handle, 0x12, &now))
+ return -EIO;
+ return now;
+}
+
+static int ideapad_backlight_update_status(struct backlight_device *blightdev)
+{
+ if (write_ec_cmd(ideapad_handle, 0x13, blightdev->props.brightness))
+ return -EIO;
+ if (write_ec_cmd(ideapad_handle, 0x33,
+ blightdev->props.power == FB_BLANK_POWERDOWN ? 0 : 1))
+ return -EIO;
+
+ return 0;
+}
+
+static const struct backlight_ops ideapad_backlight_ops = {
+ .get_brightness = ideapad_backlight_get_brightness,
+ .update_status = ideapad_backlight_update_status,
+};
+
+static int ideapad_backlight_init(struct ideapad_private *priv)
+{
+ struct backlight_device *blightdev;
+ struct backlight_properties props;
+ unsigned long max, now, power;
+
+ if (read_ec_data(ideapad_handle, 0x11, &max))
+ return -EIO;
+ if (read_ec_data(ideapad_handle, 0x12, &now))
+ return -EIO;
+ if (read_ec_data(ideapad_handle, 0x18, &power))
+ return -EIO;
+
+ memset(&props, 0, sizeof(struct backlight_properties));
+ props.max_brightness = max;
+ props.type = BACKLIGHT_PLATFORM;
+ blightdev = backlight_device_register("ideapad",
+ &priv->platform_device->dev,
+ priv,
+ &ideapad_backlight_ops,
+ &props);
+ if (IS_ERR(blightdev)) {
+ pr_err("Could not register backlight device\n");
+ return PTR_ERR(blightdev);
+ }
+
+ priv->blightdev = blightdev;
+ blightdev->props.brightness = now;
+ blightdev->props.power = power ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
+ backlight_update_status(blightdev);
+
+ return 0;
+}
+
+static void ideapad_backlight_exit(struct ideapad_private *priv)
+{
+ if (priv->blightdev)
+ backlight_device_unregister(priv->blightdev);
+ priv->blightdev = NULL;
+}
+
+static void ideapad_backlight_notify_power(struct ideapad_private *priv)
+{
+ unsigned long power;
+ struct backlight_device *blightdev = priv->blightdev;
+
+ if (read_ec_data(ideapad_handle, 0x18, &power))
+ return;
+ blightdev->props.power = power ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
+}
+
+static void ideapad_backlight_notify_brightness(struct ideapad_private *priv)
+{
+ unsigned long now;
+
+ /* if we control brightness via acpi video driver */
+ if (priv->blightdev == NULL) {
+ read_ec_data(ideapad_handle, 0x12, &now);
+ return;
+ }
+
+ backlight_force_update(priv->blightdev, BACKLIGHT_UPDATE_HOTKEY);
+}
+