[PATCH] video: Add copy_fb_to_hw op

[Frederik Aalund]

Some devices have their own framebuffer memory that is not
shared directly with the CPU. For said devices, we need to
copy U-boot's framebuffer (priv->fb) to the device's own
framebuffer memory. E.g., via SPI.

To support these devices, I've added the copy_fb_to_hw op.
It's optional, so existing drivers do not need to define this
op.

I've used this new op to add support for the
SSD2119 display panel driver over 4-wire SPI. I'll add this
video driver in a subsequent patch.

Signed-off-by: Frederik Aalund <fpa at sbtinstruments.com>
Cc: agust at denx.de 

---
 drivers/video/video-uclass.c | 14 ++++++++++++++
 include/video.h              |  8 +++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/video/video-uclass.c b/drivers/video/video-uclass.c
index 12057c8a5b..6921f1ec2b 100644
--- a/drivers/video/video-uclass.c
+++ b/drivers/video/video-uclass.c
@@ -147,6 +147,8 @@ void video_set_default_colors(struct udevice *dev, bool invert)
 /* Flush video activity to the caches */
 void video_sync(struct udevice *vid, bool force)
 {
+	int ret;
+	struct video_ops *ops = video_get_ops(vid);
 	/*
 	 * flush_dcache_range() is declared in common.h but it seems that some
 	 * architectures do not actually implement it. Is there a way to find
@@ -169,6 +171,18 @@ void video_sync(struct udevice *vid, bool force)
 		last_sync = get_timer(0);
 	}
 #endif
+	/*
+	 * Some devices have their own framebuffer memory that is not
+	 * shared directly with the CPU. For said devices, we need to
+	 * copy U-boot's framebuffer (priv->fb) to the device's own
+	 * framebuffer memory. E.g., via SPI.
+	 */
+	if (ops->copy_fb_to_hw) {
+		ret = ops->copy_fb_to_hw(vid);
+		if (ret) {
+			dev_err(vid, "Could not copy frame buffer to hardware: %d\n", ret);
+		}
+	}
 }
 
 void video_sync_all(void)
diff --git a/include/video.h b/include/video.h
index 485071d072..a72807e3cb 100644
--- a/include/video.h
+++ b/include/video.h
@@ -96,8 +96,14 @@ struct video_priv {
 	u8 bg_col_idx;
 };
 
-/* Placeholder - there are no video operations at present */
 struct video_ops {
+	/**
+	 * copy_fb_to_hw() - Copy the current frame buffer to the hardware
+	 *
+	 * @dev:	Video device
+	 * @return 0 if OK, -ve on error
+	 */
+	int (*copy_fb_to_hw)(struct udevice *dev);
 };
 
 #define video_get_ops(dev)        ((struct video_ops *)(dev)->driver->ops)
-- 
2.25.1