[PATCH v2 21/26] video: Correctly handle multiple framebuffers

[Simon Glass <sjg@chromium.org>]

At present video_bottom is set to the bottom of each framebuffer when it
is allocated. This is not correct, since it should hold the bottom of the
entire area available for framebuffers.

Fix this by adding a private address in the uclass which keeps track of
the next available spot for a framebuffer.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
---

Changes in v2: None

 drivers/video/video-uclass.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/video/video-uclass.c b/drivers/video/video-uclass.c
index 4d6f950eab..aa543cb5df 100644
--- a/drivers/video/video-uclass.c
+++ b/drivers/video/video-uclass.c
@@ -46,6 +46,19 @@
  */
 DECLARE_GLOBAL_DATA_PTR;
 
+/**
+ * struct video_uc_priv - Information for the video uclass
+ *
+ * @video_ptr: Current allocation position of the video framebuffer pointer.
+ *	While binding devices after relocation, this points to the next
+ *	available address to use for a device's framebuffer. It starts at
+ *	gd->video_top and works downwards, running out of space when it hits
+ *	gd->video_bottom.
+ */
+struct video_uc_priv {
+	ulong video_ptr;
+};
+
 void video_set_flush_dcache(struct udevice *dev, bool flush)
 {
 	struct video_priv *priv = dev_get_uclass_priv(dev);
@@ -350,12 +363,21 @@ static int video_post_probe(struct udevice *dev)
 /* Post-relocation, allocate memory for the frame buffer */
 static int video_post_bind(struct udevice *dev)
 {
-	ulong addr = gd->video_top;
+	struct video_uc_priv *uc_priv;
+	ulong addr;
 	ulong size;
 
 	/* Before relocation there is nothing to do here */
 	if (!(gd->flags & GD_FLG_RELOC))
 		return 0;
+
+	/* Set up the video pointer, if this is the first device */
+	uc_priv = dev->uclass->priv;
+	if (!uc_priv->video_ptr)
+		uc_priv->video_ptr = gd->video_top;
+
+	/* Allocate framebuffer space for this device */
+	addr = uc_priv->video_ptr;
 	size = alloc_fb(dev, &addr);
 	if (addr < gd->video_bottom) {
 		/* Device tree node may need the 'u-boot,dm-pre-reloc' or
@@ -367,7 +389,7 @@ static int video_post_bind(struct udevice *dev)
 	}
 	debug("%s: Claiming %lx bytes at %lx for video device '%s'\n",
 	      __func__, size, addr, dev->name);
-	gd->video_bottom = addr;
+	uc_priv->video_ptr = addr;
 
 	return 0;
 }
@@ -380,6 +402,7 @@ UCLASS_DRIVER(video) = {
 	.pre_probe	= video_pre_probe,
 	.post_probe	= video_post_probe,
 	.pre_remove	= video_pre_remove,
+	.priv_auto_alloc_size	= sizeof(struct video_uc_priv),
 	.per_device_auto_alloc_size	= sizeof(struct video_priv),
 	.per_device_platdata_auto_alloc_size = sizeof(struct video_uc_platdata),
 };
-- 
2.27.0.rc0.183.gde8f92d652-goog