backlight: Allow properties to be passed at registration

Values such as max_brightness should be set before backlights are
registered, but the current API doesn't allow that. Add a parameter to
backlight_device_register and update drivers to ensure that they
set this correctly.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
diff --git a/drivers/video/backlight/max8925_bl.c b/drivers/video/backlight/max8925_bl.c
index c267069..c91adaf 100644
--- a/drivers/video/backlight/max8925_bl.c
+++ b/drivers/video/backlight/max8925_bl.c
@@ -104,6 +104,7 @@
 	struct max8925_backlight_pdata *pdata = NULL;
 	struct max8925_backlight_data *data;
 	struct backlight_device *bl;
+	struct backlight_properties props;
 	struct resource *res;
 	char name[MAX8925_NAME_SIZE];
 	unsigned char value;
@@ -133,14 +134,15 @@
 	data->chip = chip;
 	data->current_brightness = 0;
 
+	memset(&props, 0, sizeof(struct backlight_properties));
+	props.max_brightness = MAX_BRIGHTNESS;
 	bl = backlight_device_register(name, &pdev->dev, data,
-					&max8925_backlight_ops);
+					&max8925_backlight_ops, &props);
 	if (IS_ERR(bl)) {
 		dev_err(&pdev->dev, "failed to register backlight\n");
 		kfree(data);
 		return PTR_ERR(bl);
 	}
-	bl->props.max_brightness = MAX_BRIGHTNESS;
 	bl->props.brightness = MAX_BRIGHTNESS;
 
 	platform_set_drvdata(pdev, bl);