[RFC PATCH v2 05/13] bootsplash: Add animation support

[Max Staudt <mstaudt@suse.de>]

Each 'picture' in the splash file can consist of multiple 'blobs'.

If animation is enabled, these blobs become the frames of an animation,
in the order in which they are stored in the file.

Note: There is only one global timer, so all animations happen at
      the same frame rate. It doesn't really make sense to animate
      more than one object at a time anyway.

Furthermore, this patch introduces a check for reusing a framebuffer
where the splash has recently been painted on - in this case, we only
redraw the objects that are animated.

Signed-off-by: Max Staudt <mstaudt@suse.de>
---
 drivers/video/fbdev/core/bootsplash.c          | 62 +++++++++++++++++++++++---
 drivers/video/fbdev/core/bootsplash_internal.h | 13 +++++-
 drivers/video/fbdev/core/bootsplash_load.c     | 21 +++++++++
 drivers/video/fbdev/core/bootsplash_render.c   | 30 ++++++++++++-
 include/uapi/linux/bootsplash_file.h           | 35 ++++++++++++++-
 5 files changed, 151 insertions(+), 10 deletions(-)

diff --git a/drivers/video/fbdev/core/bootsplash.c b/drivers/video/fbdev/core/bootsplash.c
index 815b007f81ca..c8642142cfea 100644
--- a/drivers/video/fbdev/core/bootsplash.c
+++ b/drivers/video/fbdev/core/bootsplash.c
@@ -53,6 +53,14 @@ static void splash_callback_redraw_vc(struct work_struct *ignored)
 	console_unlock();
 }
 
+static void splash_callback_animation(struct work_struct *ignored)
+{
+	if (bootsplash_would_render_now()) {
+		/* This will also re-schedule this delayed worker */
+		splash_callback_redraw_vc(ignored);
+	}
+}
+
 
 static bool is_fb_compatible(const struct fb_info *info)
 {
@@ -103,17 +111,44 @@ static bool is_fb_compatible(const struct fb_info *info)
  */
 void bootsplash_render_full(struct fb_info *info)
 {
+	bool is_update = false;
+
 	mutex_lock(&splash_state.data_lock);
 
-	if (!is_fb_compatible(info))
-		goto out;
+	/*
+	 * If we've painted on this FB recently, we don't have to do
+	 * the sanity checks and background drawing again.
+	 */
+	if (splash_state.splash_fb == info)
+		is_update = true;
+
+
+	if (!is_update) {
+		/* Check whether we actually support this FB. */
+		splash_state.splash_fb = NULL;
+
+		if (!is_fb_compatible(info))
+			goto out;
+
+		/* Draw the background only once */
+		bootsplash_do_render_background(info, splash_state.file);
 
-	bootsplash_do_render_background(info, splash_state.file);
+		/* Mark this FB as last seen */
+		splash_state.splash_fb = info;
+	}
 
-	bootsplash_do_render_pictures(info, splash_state.file);
+	bootsplash_do_render_pictures(info, splash_state.file, is_update);
 
 	bootsplash_do_render_flush(info);
 
+	bootsplash_do_step_animations(splash_state.file);
+
+	/* Schedule update for animated splash screens */
+	if (splash_state.file->frame_ms > 0)
+		schedule_delayed_work(&splash_state.dwork_animation,
+				      msecs_to_jiffies(
+				      splash_state.file->frame_ms));
+
 out:
 	mutex_unlock(&splash_state.data_lock);
 }
@@ -169,8 +204,14 @@ void bootsplash_enable(void)
 
 	was_enabled = test_and_set_bit(0, &splash_state.enabled);
 
-	if (!was_enabled)
+	if (!was_enabled) {
+		/* Force a full redraw when the splash is re-activated */
+		mutex_lock(&splash_state.data_lock);
+		splash_state.splash_fb = NULL;
+		mutex_unlock(&splash_state.data_lock);
+
 		schedule_work(&splash_state.work_redraw_vc);
+	}
 }
 
 
@@ -227,6 +268,14 @@ ATTRIBUTE_GROUPS(splash_dev);
  */
 static int splash_resume(struct device *device)
 {
+	/*
+	 * Force full redraw on resume since we've probably lost the
+	 * framebuffer's contents meanwhile
+	 */
+	mutex_lock(&splash_state.data_lock);
+	splash_state.splash_fb = NULL;
+	mutex_unlock(&splash_state.data_lock);
+
 	if (bootsplash_would_render_now())
 		schedule_work(&splash_state.work_redraw_vc);
 
@@ -235,6 +284,7 @@ static int splash_resume(struct device *device)
 
 static int splash_suspend(struct device *device)
 {
+	cancel_delayed_work_sync(&splash_state.dwork_animation);
 	cancel_work_sync(&splash_state.work_redraw_vc);
 
 	return 0;
@@ -296,6 +346,8 @@ void bootsplash_init(void)
 	set_bit(0, &splash_state.enabled);
 
 	INIT_WORK(&splash_state.work_redraw_vc, splash_callback_redraw_vc);
+	INIT_DELAYED_WORK(&splash_state.dwork_animation,
+			  splash_callback_animation);
 
 
 	if (!splash_state.bootfile || !strlen(splash_state.bootfile))
diff --git a/drivers/video/fbdev/core/bootsplash_internal.h b/drivers/video/fbdev/core/bootsplash_internal.h
index 0acb383aa4e3..b3a74835d90f 100644
--- a/drivers/video/fbdev/core/bootsplash_internal.h
+++ b/drivers/video/fbdev/core/bootsplash_internal.h
@@ -37,6 +37,8 @@ struct splash_pic_priv {
 
 	struct splash_blob_priv *blobs;
 	u16 blobs_loaded;
+
+	u16 anim_nextframe;
 };
 
 
@@ -45,6 +47,12 @@ struct splash_file_priv {
 	const struct splash_file_header *header;
 
 	struct splash_pic_priv *pics;
+
+	/*
+	 * A local copy of the frame delay in the header.
+	 * We modify it to keep the code simple.
+	 */
+	u16 frame_ms;
 };
 
 
@@ -71,6 +79,7 @@ struct splash_priv {
 	struct platform_device *splash_device;
 
 	struct work_struct work_redraw_vc;
+	struct delayed_work dwork_animation;
 
 	/* Splash data structures including lock for everything below */
 	struct mutex data_lock;
@@ -88,8 +97,10 @@ struct splash_priv {
 void bootsplash_do_render_background(struct fb_info *info,
 				     const struct splash_file_priv *fp);
 void bootsplash_do_render_pictures(struct fb_info *info,
-				   const struct splash_file_priv *fp);
+				   const struct splash_file_priv *fp,
+				   bool is_update);
 void bootsplash_do_render_flush(struct fb_info *info);
+void bootsplash_do_step_animations(struct splash_file_priv *fp);
 
 
 void bootsplash_free_file(struct splash_file_priv *fp);
diff --git a/drivers/video/fbdev/core/bootsplash_load.c b/drivers/video/fbdev/core/bootsplash_load.c
index fd807571ab7d..1f661b2d4cc9 100644
--- a/drivers/video/fbdev/core/bootsplash_load.c
+++ b/drivers/video/fbdev/core/bootsplash_load.c
@@ -71,6 +71,7 @@ struct splash_file_priv *bootsplash_load_firmware(struct device *device,
 {
 	const struct firmware *fw;
 	struct splash_file_priv *fp;
+	bool have_anim = false;
 	unsigned int i;
 	const u8 *walker;
 
@@ -135,6 +136,13 @@ struct splash_file_priv *bootsplash_load_firmware(struct device *device,
 			goto err;
 		}
 
+		if (ph->anim_type > SPLASH_ANIM_LOOP_FORWARD) {
+			pr_warn("Picture %u: Unsupported animation type %u.\n",
+				i, ph->anim_type);
+
+			ph->anim_type = SPLASH_ANIM_NONE;
+		}
+
 		pp->pic_header = ph;
 		pp->blobs = vzalloc(ph->num_blobs
 					* sizeof(struct splash_blob_priv));
@@ -202,6 +210,7 @@ struct splash_file_priv *bootsplash_load_firmware(struct device *device,
 	/* Walk over pictures and ensure all blob slots are filled */
 	for (i = 0; i < fp->header->num_pics; i++) {
 		struct splash_pic_priv *pp = &fp->pics[i];
+		const struct splash_pic_header *ph = pp->pic_header;
 
 		if (pp->blobs_loaded != pp->pic_header->num_blobs) {
 			pr_err("Picture %u doesn't have all blob slots filled.\n",
@@ -209,8 +218,20 @@ struct splash_file_priv *bootsplash_load_firmware(struct device *device,
 
 			goto err;
 		}
+
+		if (ph->anim_type
+		    && ph->num_blobs > 1
+		    && ph->anim_loop < pp->blobs_loaded)
+			have_anim = true;
 	}
 
+	if (!have_anim)
+		/* Disable animation timer if there is nothing to animate */
+		fp->frame_ms = 0;
+	else
+		/* Enforce minimum delay between frames */
+		fp->frame_ms = max((u16)20, fp->header->frame_ms);
+
 	pr_info("Loaded (%ld bytes, %u pics, %u blobs).\n",
 		fw->size,
 		fp->header->num_pics,
diff --git a/drivers/video/fbdev/core/bootsplash_render.c b/drivers/video/fbdev/core/bootsplash_render.c
index 07e3a4eab811..76033606ca8a 100644
--- a/drivers/video/fbdev/core/bootsplash_render.c
+++ b/drivers/video/fbdev/core/bootsplash_render.c
@@ -148,7 +148,8 @@ void bootsplash_do_render_background(struct fb_info *info,
 
 
 void bootsplash_do_render_pictures(struct fb_info *info,
-				   const struct splash_file_priv *fp)
+				   const struct splash_file_priv *fp,
+				   bool is_update)
 {
 	unsigned int i;
 
@@ -161,7 +162,11 @@ void bootsplash_do_render_pictures(struct fb_info *info,
 		if (pp->blobs_loaded < 1)
 			continue;
 
-		bp = &pp->blobs[0];
+		/* Skip static pictures when refreshing animations */
+		if (ph->anim_type == SPLASH_ANIM_NONE && is_update)
+			continue;
+
+		bp = &pp->blobs[pp->anim_nextframe];
 
 		if (!bp || bp->blob_header->type != 0)
 			continue;
@@ -351,3 +356,24 @@ void bootsplash_do_render_flush(struct fb_info *info)
 		info->fbops->fb_copyarea(info, &area);
 	}
 }
+
+
+void bootsplash_do_step_animations(struct splash_file_priv *fp)
+{
+	unsigned int i;
+
+	/* Step every animation once */
+	for (i = 0; i < fp->header->num_pics; i++) {
+		struct splash_pic_priv *pp = &fp->pics[i];
+
+		if (pp->blobs_loaded < 2
+		    || pp->pic_header->anim_loop > pp->blobs_loaded)
+			continue;
+
+		if (pp->pic_header->anim_type == SPLASH_ANIM_LOOP_FORWARD) {
+			pp->anim_nextframe++;
+			if (pp->anim_nextframe >= pp->pic_header->num_blobs)
+				pp->anim_nextframe = pp->pic_header->anim_loop;
+		}
+	}
+}
diff --git a/include/uapi/linux/bootsplash_file.h b/include/uapi/linux/bootsplash_file.h
index 71cedcc68933..b3af0a3c6487 100644
--- a/include/uapi/linux/bootsplash_file.h
+++ b/include/uapi/linux/bootsplash_file.h
@@ -77,7 +77,17 @@ struct splash_file_header {
 	uint16_t num_blobs;
 	uint8_t num_pics;
 
-	uint8_t padding[103];
+	uint8_t unused_1;
+
+	/*
+	 * Milliseconds to wait before painting the next frame in
+	 * an animation.
+	 * This is actually a minimum, as the system is allowed to
+	 * stall for longer between frames.
+	 */
+	uint16_t frame_ms;
+
+	uint8_t padding[100];
 } __attribute__((__packed__));
 
 
@@ -116,7 +126,23 @@ struct splash_pic_header {
 	 */
 	uint16_t position_offset;
 
-	uint8_t padding[24];
+	/*
+	 * Animation type.
+	 *  0 - off
+	 *  1 - forward loop
+	 */
+	uint8_t anim_type;
+
+	/*
+	 * Animation loop point.
+	 * Actual meaning depends on animation type:
+	 * Type 0 - Unused
+	 *      1 - Frame at which to restart the forward loop
+	 *          (allowing for "intro" frames)
+	 */
+	uint8_t anim_loop;
+
+	uint8_t padding[22];
 } __attribute__((__packed__));
 
 
@@ -158,4 +184,9 @@ enum splash_position {
 	SPLASH_POS_FLAG_CORNER = 0x10,
 };
 
+enum splash_anim_type {
+	SPLASH_ANIM_NONE = 0,
+	SPLASH_ANIM_LOOP_FORWARD = 1,
+};
+
 #endif
-- 
2.12.3