minnowmax: Enable the copy framebuffer

Update the video driver to support this feature and enable it on
minnowmax to speed up the display.

With this change, the time taken to print the environment to the display
without CONFIG_CONSOLE_SCROLL_LINES is reduced from over 13 seconds to
300ms, at 1280x1024.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/video/vesa.c b/drivers/video/vesa.c
index 6c03611..9656326 100644
--- a/drivers/video/vesa.c
+++ b/drivers/video/vesa.c
@@ -5,12 +5,39 @@
 
 #include <common.h>
 #include <dm.h>
+#include <log.h>
 #include <pci.h>
 #include <vbe.h>
+#include <video.h>
+#include <asm/mtrr.h>
 
 static int vesa_video_probe(struct udevice *dev)
 {
-	return vbe_setup_video(dev, NULL);
+	struct video_uc_platdata *plat = dev_get_uclass_platdata(dev);
+	ulong fbbase;
+	int ret;
+
+	ret = vbe_setup_video(dev, NULL);
+	if (ret)
+		return log_ret(ret);
+
+	/* Use write-combining for the graphics memory, 256MB */
+	fbbase = IS_ENABLED(CONFIG_VIDEO_COPY) ? plat->copy_base : plat->base;
+	mtrr_add_request(MTRR_TYPE_WRCOMB, fbbase, 256 << 20);
+	mtrr_commit(true);
+
+	return 0;
+}
+
+static int vesa_video_bind(struct udevice *dev)
+{
+	struct video_uc_platdata *uc_plat = dev_get_uclass_platdata(dev);
+
+	/* Set the maximum supported resolution */
+	uc_plat->size = 2560 * 1600 * 4;
+	log_debug("%s: Frame buffer size %x\n", __func__, uc_plat->size);
+
+	return 0;
 }
 
 static const struct udevice_id vesa_video_ids[] = {
@@ -22,6 +49,7 @@
 	.name	= "vesa_video",
 	.id	= UCLASS_VIDEO,
 	.of_match = vesa_video_ids,
+	.bind	= vesa_video_bind,
 	.probe	= vesa_video_probe,
 };