[PATCH v7 6/6] drm/client: splash: pick the image source in one place

["Màxim Pedraza Padilla" <maximpedraza@gmail.com>]

The client chooses between two sources with a boolean: the BGRT if the
firmware left one, otherwise the BMP loaded as firmware. A third one is
coming, and with it an order of preference that a boolean cannot hold.

Name the source in use with an enum, picked once by
drm_splash_pick_source(), and have drm_splash_image_load() switch on
it. No functional change.

v7:
- DRM_SPLASH_SRC_FW for DRM_SPLASH_SRC_BMP: the BGRT is a BMP too

Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Màxim Pedraza Padilla <maximpedraza@gmail.com>
---
 drivers/gpu/drm/clients/drm_splash.c | 46 ++++++++++++++++++++++------
 1 file changed, 37 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/clients/drm_splash.c b/drivers/gpu/drm/clients/drm_splash.c
index d54cf628cf17..fbbdc034e417 100644
--- a/drivers/gpu/drm/clients/drm_splash.c
+++ b/drivers/gpu/drm/clients/drm_splash.c
@@ -39,6 +39,16 @@
  * a static image.
  */
 
+/*
+ * Where the image comes from. drm_splash_pick_source() sets the order of
+ * preference; NONE is zero, so that a new splash starts without a source.
+ */
+enum drm_splash_source {
+	DRM_SPLASH_SRC_NONE,
+	DRM_SPLASH_SRC_BGRT,
+	DRM_SPLASH_SRC_FW,
+};
+
 struct drm_splash_scanout {
 	int id;
 	/* Modesets scanning this buffer out, by position in the list */
@@ -91,7 +101,7 @@ struct drm_splash {
 	const struct firmware *fw;
 	void *map_data;
 
-	bool use_bgrt;
+	enum drm_splash_source src;
 };
 
 static struct drm_splash *client_to_drm_splash(struct drm_client_dev *client)
@@ -439,7 +449,7 @@ static int drm_splash_bmp_to_scanout(struct drm_splash *splash,
 		return -EINVAL;
 	}
 
-	if (splash->use_bgrt) {
+	if (splash->src == DRM_SPLASH_SRC_BGRT) {
 		x_pad = efi_bgrt_image_offset_x();
 		y_pad = efi_bgrt_image_offset_y();
 
@@ -509,13 +519,31 @@ static int drm_splash_bmp_to_scanout(struct drm_splash *splash,
 static int drm_splash_image_load(struct drm_splash *splash, const u8 **img_data,
 				 size_t *img_data_len)
 {
-	if (splash->use_bgrt)
+	switch (splash->src) {
+	case DRM_SPLASH_SRC_BGRT:
 		return drm_splash_bgrt_load(splash, img_data, img_data_len);
+	case DRM_SPLASH_SRC_FW:
+		return drm_splash_fw_load(splash, img_data, img_data_len);
+	case DRM_SPLASH_SRC_NONE:
+		break;
+	}
 
-	if (!IS_ENABLED(CONFIG_DRM_CLIENT_SPLASH_SRC_FW))
-		return -ENOENT;
+	return -ENOENT;
+}
+
+/*
+ * Pick the one source the image will come from: the BGRT is whatever the
+ * firmware shows, and the BMP loaded as firmware is the fallback. With
+ * neither, only the background colour is drawn.
+ */
+static enum drm_splash_source drm_splash_pick_source(struct drm_splash *splash)
+{
+	if (drm_splash_bgrt_available(splash))
+		return DRM_SPLASH_SRC_BGRT;
+	if (IS_ENABLED(CONFIG_DRM_CLIENT_SPLASH_SRC_FW))
+		return DRM_SPLASH_SRC_FW;
 
-	return drm_splash_fw_load(splash, img_data, img_data_len);
+	return DRM_SPLASH_SRC_NONE;
 }
 
 /* At unregister, once nothing else can use the image */
@@ -858,10 +886,10 @@ static void drm_splash_rebuild(struct drm_splash *splash)
 
 	if (!splash->source_picked) {
 		splash->source_picked = true;
-		splash->use_bgrt = drm_splash_bgrt_available(splash);
+		splash->src = drm_splash_pick_source(splash);
 
-		/* If no other image has been loaded, try to load a BMP as firmware */
-		if (IS_ENABLED(CONFIG_DRM_CLIENT_SPLASH_SRC_FW) && !splash->use_bgrt) {
+		/* The BMP loaded as firmware is the only source that arrives later */
+		if (splash->src == DRM_SPLASH_SRC_FW) {
 			ret = drm_splash_fw_request(splash);
 			splash->fw_requested = !ret;
 			if (ret)
-- 
2.39.5