dm: video: test: Add tests for the video uclass

Add tests that check that the video console is working correcty. Also check
that text output produces the expected result. Test coverage includes
character output, wrapping and scrolling.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Anatolij Gustschin <agust@denx.de>
diff --git a/test/dm/video.c b/test/dm/video.c
new file mode 100644
index 0000000..b197b01
--- /dev/null
+++ b/test/dm/video.c
@@ -0,0 +1,190 @@
+/*
+ * Copyright (c) 2014 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <bzlib.h>
+#include <dm.h>
+#include <mapmem.h>
+#include <os.h>
+#include <video.h>
+#include <video_console.h>
+#include <dm/test.h>
+#include <dm/uclass-internal.h>
+#include <test/ut.h>
+
+/*
+ * These tests use the standard sandbox frame buffer, the resolution of which
+ * is defined in the device tree. This only supports 16bpp so the tests only
+ * test that code path. It would be possible to adjust this fairly easily,
+ * by adjusting the bpix value in struct sandbox_sdl_plat. However the code
+ * in sandbox_sdl_sync() would also need to change to handle the different
+ * surface depth.
+ */
+DECLARE_GLOBAL_DATA_PTR;
+
+/* Basic test of the video uclass */
+static int dm_test_video_base(struct unit_test_state *uts)
+{
+	struct video_priv *priv;
+	struct udevice *dev;
+
+	ut_assertok(uclass_get_device(UCLASS_VIDEO, 0, &dev));
+	ut_asserteq(1366, video_get_xsize(dev));
+	ut_asserteq(768, video_get_ysize(dev));
+	priv = dev_get_uclass_priv(dev);
+	ut_asserteq(priv->fb_size, 1366 * 768 * 2);
+
+	return 0;
+}
+DM_TEST(dm_test_video_base, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+
+/**
+ * compress_frame_buffer() - Compress the frame buffer and return its size
+ *
+ * We want to write tests which perform operations on the video console and
+ * check that the frame buffer ends up with the correct contents. But it is
+ * painful to store 'known good' images for comparison with the frame
+ * buffer. As an alternative, we can compress the frame buffer and check the
+ * size of the compressed data. This provides a pretty good level of
+ * certainty and the resulting tests need only check a single value.
+ *
+ * @dev:	Video device
+ * @return compressed size of the frame buffer, or -ve on error
+ */
+static int compress_frame_buffer(struct udevice *dev)
+{
+	struct video_priv *priv = dev_get_uclass_priv(dev);
+	uint destlen;
+	void *dest;
+	int ret;
+
+	destlen = priv->fb_size;
+	dest = malloc(priv->fb_size);
+	if (!dest)
+		return -ENOMEM;
+	ret = BZ2_bzBuffToBuffCompress(dest, &destlen,
+				       priv->fb, priv->fb_size,
+				       3, 0, 0);
+	free(dest);
+	if (ret)
+		return ret;
+
+	return destlen;
+}
+
+/*
+ * Call this function at any point to halt and show the current display. Be
+ * sure to run the test with the -l flag.
+ */
+static void __maybe_unused see_output(void)
+{
+	video_sync_all();
+	while (1);
+}
+
+/* Test text output works on the video console */
+static int dm_test_video_text(struct unit_test_state *uts)
+{
+	struct udevice *dev, *con;
+	int i;
+
+#define WHITE		0xffff
+#define SCROLL_LINES	100
+
+	ut_assertok(uclass_get_device(UCLASS_VIDEO, 0, &dev));
+	ut_asserteq(46, compress_frame_buffer(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));
+
+	vidconsole_putc_xy(con, 0, 0, ' ');
+	ut_asserteq(46, compress_frame_buffer(dev));
+
+	for (i = 0; i < 20; i++)
+		vidconsole_putc_xy(con, i * 8, 0, ' ' + i);
+	ut_asserteq(273, compress_frame_buffer(dev));
+
+	vidconsole_set_row(con, 0, WHITE);
+	ut_asserteq(46, compress_frame_buffer(dev));
+
+	for (i = 0; i < 20; i++)
+		vidconsole_putc_xy(con, i * 8, 0, ' ' + i);
+	ut_asserteq(273, compress_frame_buffer(dev));
+
+	return 0;
+}
+DM_TEST(dm_test_video_text, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+
+/* Test handling of special characters in the console */
+static int dm_test_video_chars(struct unit_test_state *uts)
+{
+	struct udevice *dev, *con;
+	const char *test_string = "Well\b\b\b\bxhe is\r \n\ta very modest  \bman\n\t\tand Has much to\b\bto be modest about.";
+	const char *s;
+
+	ut_assertok(uclass_get_device(UCLASS_VIDEO, 0, &dev));
+	ut_assertok(uclass_get_device(UCLASS_VIDEO_CONSOLE, 0, &con));
+	for (s = test_string; *s; s++)
+		vidconsole_put_char(con, *s);
+	ut_asserteq(466, compress_frame_buffer(dev));
+
+	return 0;
+}
+DM_TEST(dm_test_video_chars, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);
+
+/**
+ * check_vidconsole_output() - Run a text console test
+ *
+ * @uts:	Test state
+ * @rot:	Console rotation (0, 90, 180, 270)
+ * @wrap_size:	Expected size of compressed frame buffer for the wrap test
+ * @scroll_size: Same for the scroll test
+ * @return 0 on success
+ */
+static int check_vidconsole_output(struct unit_test_state *uts, int rot,
+				   int wrap_size, int scroll_size)
+{
+	struct udevice *dev, *con;
+	struct sandbox_sdl_plat *plat;
+	int i;
+
+	ut_assertok(uclass_find_device(UCLASS_VIDEO, 0, &dev));
+	ut_assert(!device_active(dev));
+	plat = dev_get_platdata(dev);
+	plat->rot = rot;
+
+	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));
+
+	/* Check display wrap */
+	for (i = 0; i < 120; i++)
+		vidconsole_put_char(con, 'A' + i % 50);
+	ut_asserteq(wrap_size, compress_frame_buffer(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));
+
+	/* 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));
+
+	return 0;
+}
+
+/* Test text output through the console uclass */
+static int dm_test_video_context(struct unit_test_state *uts)
+{
+	return check_vidconsole_output(uts, 0, 788, 453);
+}
+DM_TEST(dm_test_video_context, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);