video: sandbox: Add support for the copy framebuffer

Enable this feature on sandbox by updating the SDL driver to have two
framebuffers.

Update the video tests to check that the copy framebuffer is kept in sync.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index 8cf2ad5..8a9ec87 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -219,6 +219,7 @@
 CONFIG_USB_EMUL=y
 CONFIG_USB_KEYBOARD=y
 CONFIG_DM_VIDEO=y
+CONFIG_VIDEO_COPY=y
 CONFIG_CONSOLE_ROTATION=y
 CONFIG_CONSOLE_TRUETYPE=y
 CONFIG_CONSOLE_TRUETYPE_CANTORAONE=y
diff --git a/drivers/video/sandbox_sdl.c b/drivers/video/sandbox_sdl.c
index c678e72..f529a35 100644
--- a/drivers/video/sandbox_sdl.c
+++ b/drivers/video/sandbox_sdl.c
@@ -23,6 +23,7 @@
 
 static int sandbox_sdl_probe(struct udevice *dev)
 {
+	struct video_uc_platdata *uc_plat = dev_get_uclass_platdata(dev);
 	struct sandbox_sdl_plat *plat = dev_get_platdata(dev);
 	struct video_priv *uc_priv = dev_get_uclass_priv(dev);
 	struct sandbox_state *state = state_get_current();
@@ -40,6 +41,8 @@
 	uc_priv->rot = plat->rot;
 	uc_priv->vidconsole_drv_name = plat->vidconsole_drv_name;
 	uc_priv->font_size = plat->font_size;
+	if (IS_ENABLED(CONFIG_VIDEO_COPY))
+		uc_plat->copy_base = uc_plat->base - uc_plat->size / 2;
 
 	return 0;
 }
@@ -55,7 +58,11 @@
 	plat->bpix = dev_read_u32_default(dev, "log2-depth", VIDEO_BPP16);
 	plat->rot = dev_read_u32_default(dev, "rotate", 0);
 	uc_plat->size = plat->xres * plat->yres * (1 << plat->bpix) / 8;
-	debug("%s: Frame buffer size %x\n", __func__, uc_plat->size);
+
+	/* Allow space for two buffers, the lower one being the copy buffer */
+	log_debug("Frame buffer size %x\n", uc_plat->size);
+	if (IS_ENABLED(CONFIG_VIDEO_COPY))
+		uc_plat->size *= 2;
 
 	return ret;
 }
diff --git a/test/dm/video.c b/test/dm/video.c
index 729c31b..19f78b6 100644
--- a/test/dm/video.c
+++ b/test/dm/video.c
@@ -51,12 +51,18 @@
  * size of the compressed data. This provides a pretty good level of
  * certainty and the resulting tests need only check a single value.
  *
+ * If the copy framebuffer is enabled, this compares it to the main framebuffer
+ * too.
+ *
+ * @uts:	Test state
  * @dev:	Video device
  * @return compressed size of the frame buffer, or -ve on error
  */
-static int compress_frame_buffer(struct udevice *dev)
+static int compress_frame_buffer(struct unit_test_state *uts,
+				 struct udevice *dev)
 {
 	struct video_priv *priv = dev_get_uclass_priv(dev);
+	struct video_priv *uc_priv = dev_get_uclass_priv(dev);
 	uint destlen;
 	void *dest;
 	int ret;
@@ -72,6 +78,13 @@
 	if (ret)
 		return ret;
 
+	/* Check here that the copy frame buffer is working correctly */
+	if (IS_ENABLED(CONFIG_VIDEO_COPY)) {
+		ut_assertf(!memcmp(uc_priv->fb, uc_priv->copy_fb,
+				   uc_priv->fb_size),
+				   "Copy framebuffer does not match fb");
+	}
+
 	return destlen;
 }
 
@@ -110,25 +123,25 @@
 
 	ut_assertok(select_vidconsole(uts, "vidconsole0"));
 	ut_assertok(uclass_get_device(UCLASS_VIDEO, 0, &dev));
-	ut_asserteq(46, compress_frame_buffer(dev));
+	ut_asserteq(46, compress_frame_buffer(uts, dev));
 
 	ut_assertok(uclass_get_device(UCLASS_VIDEO_CONSOLE, 0, &con));
 	vidconsole_putc_xy(con, 0, 0, 'a');
-	ut_asserteq(79, compress_frame_buffer(dev));
+	ut_asserteq(79, compress_frame_buffer(uts, dev));
 
 	vidconsole_putc_xy(con, 0, 0, ' ');
-	ut_asserteq(46, compress_frame_buffer(dev));
+	ut_asserteq(46, compress_frame_buffer(uts, dev));
 
 	for (i = 0; i < 20; i++)
 		vidconsole_putc_xy(con, VID_TO_POS(i * 8), 0, ' ' + i);
-	ut_asserteq(273, compress_frame_buffer(dev));
+	ut_asserteq(273, compress_frame_buffer(uts, dev));
 
 	vidconsole_set_row(con, 0, WHITE);
-	ut_asserteq(46, compress_frame_buffer(dev));
+	ut_asserteq(46, compress_frame_buffer(uts, dev));
 
 	for (i = 0; i < 20; i++)
 		vidconsole_putc_xy(con, VID_TO_POS(i * 8), 0, ' ' + i);
-	ut_asserteq(273, compress_frame_buffer(dev));
+	ut_asserteq(273, compress_frame_buffer(uts, dev));
 
 	return 0;
 }
@@ -144,7 +157,7 @@
 	ut_assertok(uclass_get_device(UCLASS_VIDEO, 0, &dev));
 	ut_assertok(uclass_get_device(UCLASS_VIDEO_CONSOLE, 0, &con));
 	vidconsole_put_string(con, test_string);
-	ut_asserteq(466, compress_frame_buffer(dev));
+	ut_asserteq(466, compress_frame_buffer(uts, dev));
 
 	return 0;
 }
@@ -164,20 +177,20 @@
 	/* reference clear: */
 	video_clear(con->parent);
 	video_sync(con->parent, false);
-	ut_asserteq(46, compress_frame_buffer(dev));
+	ut_asserteq(46, compress_frame_buffer(uts, dev));
 
 	/* test clear escape sequence: [2J */
 	vidconsole_put_string(con, "A\tB\tC"ANSI_ESC"[2J");
-	ut_asserteq(46, compress_frame_buffer(dev));
+	ut_asserteq(46, compress_frame_buffer(uts, dev));
 
 	/* test set-cursor: [%d;%df */
 	vidconsole_put_string(con, "abc"ANSI_ESC"[2;2fab"ANSI_ESC"[4;4fcd");
-	ut_asserteq(143, compress_frame_buffer(dev));
+	ut_asserteq(143, compress_frame_buffer(uts, dev));
 
 	/* test colors (30-37 fg color, 40-47 bg color) */
 	vidconsole_put_string(con, ANSI_ESC"[30;41mfoo"); /* black on red */
 	vidconsole_put_string(con, ANSI_ESC"[33;44mbar"); /* yellow on blue */
-	ut_asserteq(272, compress_frame_buffer(dev));
+	ut_asserteq(272, compress_frame_buffer(uts, dev));
 
 	return 0;
 }
@@ -208,24 +221,24 @@
 
 	ut_assertok(uclass_get_device(UCLASS_VIDEO, 0, &dev));
 	ut_assertok(uclass_get_device(UCLASS_VIDEO_CONSOLE, 0, &con));
-	ut_asserteq(46, compress_frame_buffer(dev));
+	ut_asserteq(46, compress_frame_buffer(uts, dev));
 
 	/* Check display wrap */
 	for (i = 0; i < 120; i++)
 		vidconsole_put_char(con, 'A' + i % 50);
-	ut_asserteq(wrap_size, compress_frame_buffer(dev));
+	ut_asserteq(wrap_size, compress_frame_buffer(uts, dev));
 
 	/* Check display scrolling */
 	for (i = 0; i < SCROLL_LINES; i++) {
 		vidconsole_put_char(con, 'A' + i % 50);
 		vidconsole_put_char(con, '\n');
 	}
-	ut_asserteq(scroll_size, compress_frame_buffer(dev));
+	ut_asserteq(scroll_size, compress_frame_buffer(uts, dev));
 
 	/* If we scroll enough, the screen becomes blank again */
 	for (i = 0; i < SCROLL_LINES; i++)
 		vidconsole_put_char(con, '\n');
-	ut_asserteq(46, compress_frame_buffer(dev));
+	ut_asserteq(46, compress_frame_buffer(uts, dev));
 
 	return 0;
 }
@@ -299,7 +312,7 @@
 	ut_assertok(read_file(uts, "tools/logos/denx.bmp", &addr));
 
 	ut_assertok(video_bmp_display(dev, addr, 0, 0, false));
-	ut_asserteq(1368, compress_frame_buffer(dev));
+	ut_asserteq(1368, compress_frame_buffer(uts, dev));
 
 	return 0;
 }
@@ -315,7 +328,7 @@
 	ut_assertok(read_file(uts, "tools/logos/denx-comp.bmp", &addr));
 
 	ut_assertok(video_bmp_display(dev, addr, 0, 0, false));
-	ut_asserteq(1368, compress_frame_buffer(dev));
+	ut_asserteq(1368, compress_frame_buffer(uts, dev));
 
 	return 0;
 }
@@ -330,7 +343,7 @@
 	ut_assertok(uclass_get_device(UCLASS_VIDEO, 0, &dev));
 	ut_assertok(uclass_get_device(UCLASS_VIDEO_CONSOLE, 0, &con));
 	vidconsole_put_string(con, test_string);
-	ut_asserteq(12237, compress_frame_buffer(dev));
+	ut_asserteq(12237, compress_frame_buffer(uts, dev));
 
 	return 0;
 }
@@ -351,7 +364,7 @@
 	ut_assertok(uclass_get_device(UCLASS_VIDEO, 0, &dev));
 	ut_assertok(uclass_get_device(UCLASS_VIDEO_CONSOLE, 0, &con));
 	vidconsole_put_string(con, test_string);
-	ut_asserteq(35030, compress_frame_buffer(dev));
+	ut_asserteq(35030, compress_frame_buffer(uts, dev));
 
 	return 0;
 }
@@ -372,7 +385,7 @@
 	ut_assertok(uclass_get_device(UCLASS_VIDEO, 0, &dev));
 	ut_assertok(uclass_get_device(UCLASS_VIDEO_CONSOLE, 0, &con));
 	vidconsole_put_string(con, test_string);
-	ut_asserteq(29018, compress_frame_buffer(dev));
+	ut_asserteq(29018, compress_frame_buffer(uts, dev));
 
 	return 0;
 }