@@ -22,6 +22,18 @@ config BACKLIGHT
This provides backlight uclass driver that enables basic panel
backlight support.
+config VIDEO_COPY
+ bool "Enable copying the frame buffer to a hardware copy"
+ depends on DM_VIDEO
+ help
+ On some machines (e.g. x86), reading from the frame buffer is very
+ slow because it is uncached. To improve performance, this feature
+ allows the frame buffer to be kept in cached memory (allocated by
+ U-Boot) and then copied to the hardware frame-buffer as needed.
+
+ To use this, your video driver must set @copy_base in
+ struct video_uc_platdata.
+
config BACKLIGHT_PWM
bool "Generic PWM based Backlight Driver"
depends on BACKLIGHT && DM_PWM
@@ -4,6 +4,7 @@
*/
#include <common.h>
+#include <console.h>
#include <cpu_func.h>
#include <dm.h>
#include <log.h>
@@ -201,6 +202,59 @@ int video_get_ysize(struct udevice *dev)
return priv->ysize;
}
+#ifdef CONFIG_VIDEO_COPY
+int video_sync_copy(struct udevice *dev, void *from, void *to)
+{
+ struct video_priv *priv = dev_get_uclass_priv(dev);
+
+ if (priv->copy_fb) {
+ long offset, size;
+
+ /* Find the offset of the first byte to copy */
+ if ((ulong)to > (ulong)from) {
+ size = to - from;
+ offset = from - priv->fb;
+ } else {
+ size = from - to;
+ offset = to - priv->fb;
+ }
+
+ /*
+ * Allow a bit of leeway for valid requests somewhere near the
+ * frame buffer
+ */
+ if (offset < -priv->fb_size || offset > 2 * priv->fb_size) {
+#ifdef DEBUG
+ char str[80];
+
+ snprintf(str, sizeof(str),
+ "[sync_copy fb=%p, from=%p, to=%p, offset=%lx]",
+ priv->fb, from, to, offset);
+ console_puts_select_stderr(true, str);
+#endif
+ return -EFAULT;
+ }
+
+ /*
+ * Silently crop the memcpy. This allows callers to avoid doing
+ * this themselves. It is common for the end pointer to go a
+ * few lines after the end of the frame buffer, since most of
+ * the update algorithms terminate a line after their last write
+ */
+ if (offset + size > priv->fb_size) {
+ size = priv->fb_size - offset;
+ } else if (offset < 0) {
+ size += offset;
+ offset = 0;
+ }
+
+ memcpy(priv->copy_fb + offset, priv->fb + offset, size);
+ }
+
+ return 0;
+}
+#endif
+
/* Set up the colour map */
static int video_pre_probe(struct udevice *dev)
{
@@ -30,11 +30,14 @@ struct udevice;
* buffer should start on. If 0, 1MB is assumed
* @size: Frame-buffer size, in bytes
* @base: Base address of frame buffer, 0 if not yet known
+ * @copy_base: Base address of a hardware copy of the frame buffer. See
+ * CONFIG_VIDEO_COPY.
*/
struct video_uc_platdata {
uint align;
uint size;
ulong base;
+ ulong copy_base;
};
enum video_polarity {
@@ -75,6 +78,8 @@ enum video_log2_bpp {
* @font_size: Font size in pixels (0 to use a default value)
* @fb: Frame buffer
* @fb_size: Frame buffer size
+ * @copy_fb: Copy of the frame buffer to keep up to date; see struct
+ * video_uc_platdata
* @line_length: Length of each frame buffer line, in bytes. This can be
* set by the driver, but if not, the uclass will set it after
* probing
@@ -101,6 +106,7 @@ struct video_priv {
*/
void *fb;
int fb_size;
+ void *copy_fb;
int line_length;
u32 colour_fg;
u32 colour_bg;
@@ -214,6 +220,29 @@ void video_set_flush_dcache(struct udevice *dev, bool flush);
*/
void video_set_default_colors(struct udevice *dev, bool invert);
+#ifdef CONFIG_VIDEO_COPY
+/**
+ * vidconsole_sync_copy() - Sync back to the copy framebuffer
+ *
+ * This ensures that the copy framebuffer has the same data as the framebuffer
+ * for a particular region. It should be called after the framebuffer is updated
+ *
+ * @from and @to can be in either order. The region between them is synced.
+ *
+ * @dev: Vidconsole device being updated
+ * @from: Start/end address within the framebuffer (->fb)
+ * @to: Other address within the frame buffer
+ * @return 0 if OK, -EFAULT if the start address is before the start of the
+ * frame buffer start
+ */
+int video_sync_copy(struct udevice *dev, void *from, void *to);
+#else
+static inline int video_sync_copy(struct udevice *dev, void *from, void *to)
+{
+ return 0;
+}
+#endif
+
#endif /* CONFIG_DM_VIDEO */
#ifndef CONFIG_DM_VIDEO