kmsprint: Decode bitfields for flags and type of hdmi mode

Decode the bitfields for the mode type and flags of Videomode
Use short names for type as it allows for consise formatting
(excluding the deprecated options, that are not expected to
be seen)

I've swapped order of flags and types as the type is expected
to be shorted so can fit in a fixed size field

Signed-off-by: Dom Cobley <popcornmix@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>

1 files changed, 111 insertions, 6 deletions

diff --git a/kms++/src/videomode.cpp b/kms++/src/videomode.cpp
index b039059..0e5acf6 100644
--- a/kms++/src/videomode.cpp
+++ b/kms++/src/videomode.cpp
@@ -110,18 +110,123 @@ static char sync_to_char(SyncPolarity pol)
 	}
 }
 
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+
+template<typename T>
+std::string join(const T& values, const std::string& delim)
+{
+	std::ostringstream ss;
+	for (const auto& v : values) {
+		if (&v != &values[0])
+			ss << delim;
+		ss << v;
+	}
+	return ss.str();
+}
+
+static const map<int, string> mode_type_map = {
+	// the deprecated ones don't care about a short name
+	{ DRM_MODE_TYPE_BUILTIN, "builtin" }, // deprecated
+	{ DRM_MODE_TYPE_CLOCK_C, "clock_c" }, // deprecated
+	{ DRM_MODE_TYPE_CRTC_C, "crtc_c" }, // deprecated
+	{ DRM_MODE_TYPE_PREFERRED, "P" },
+	{ DRM_MODE_TYPE_DEFAULT, "default" }, // deprecated
+	{ DRM_MODE_TYPE_USERDEF, "U" },
+	{ DRM_MODE_TYPE_DRIVER, "D" },
+};
+
+static const map<int, string> mode_flag_map = {
+	// the first 5 flags are displayed elsewhere
+	{ DRM_MODE_FLAG_PHSYNC, "" },
+	{ DRM_MODE_FLAG_NHSYNC, "" },
+	{ DRM_MODE_FLAG_PVSYNC, "" },
+	{ DRM_MODE_FLAG_NVSYNC, "" },
+	{ DRM_MODE_FLAG_INTERLACE, "" },
+	{ DRM_MODE_FLAG_DBLSCAN, "dblscan" },
+	{ DRM_MODE_FLAG_CSYNC, "csync" },
+	{ DRM_MODE_FLAG_PCSYNC, "pcsync" },
+	{ DRM_MODE_FLAG_NCSYNC, "ncsync" },
+	{ DRM_MODE_FLAG_HSKEW, "hskew" },
+	{ DRM_MODE_FLAG_BCAST, "bcast" }, // deprecated
+	{ DRM_MODE_FLAG_PIXMUX, "pixmux" }, // deprecated
+	{ DRM_MODE_FLAG_DBLCLK, "2x" },
+	{ DRM_MODE_FLAG_CLKDIV2, "clkdiv2" },
+};
+
+static const map<int, string> mode_3d_map = {
+	{ DRM_MODE_FLAG_3D_NONE, "" },
+	{ DRM_MODE_FLAG_3D_FRAME_PACKING, "3dfp" },
+	{ DRM_MODE_FLAG_3D_FIELD_ALTERNATIVE, "3dfa" },
+	{ DRM_MODE_FLAG_3D_LINE_ALTERNATIVE, "3dla" },
+	{ DRM_MODE_FLAG_3D_SIDE_BY_SIDE_FULL, "3dsbs" },
+	{ DRM_MODE_FLAG_3D_L_DEPTH, "3dldepth" },
+	{ DRM_MODE_FLAG_3D_L_DEPTH_GFX_GFX_DEPTH, "3dgfx" },
+	{ DRM_MODE_FLAG_3D_TOP_AND_BOTTOM, "3dtab" },
+	{ DRM_MODE_FLAG_3D_SIDE_BY_SIDE_HALF, "3dsbs" },
+};
+
+static const map<int, string> mode_aspect_map = {
+	{ DRM_MODE_FLAG_PIC_AR_NONE, "" },
+	{ DRM_MODE_FLAG_PIC_AR_4_3, "4:3" },
+	{ DRM_MODE_FLAG_PIC_AR_16_9, "16:9" },
+	{ DRM_MODE_FLAG_PIC_AR_64_27, "64:27" },
+	{ DRM_MODE_FLAG_PIC_AR_256_135, "256:135" },
+};
+
+static string mode_type_str(uint32_t val) {
+	vector<string> s;
+	for (const auto & [k, v] : mode_type_map) {
+		if (val & k) {
+			if (!v.empty())
+				s.push_back(v);
+			val &= ~k;
+		}
+	}
+	// any unknown bits
+	if (val != 0)
+		s.push_back(fmt::format("{:#x}", val));
+	return join(s, "|");
+}
+
+static string mode_flag_str(uint32_t val) {
+	vector<string> s;
+	for (const auto& [k, v] : mode_flag_map) {
+		if (val & k) {
+			if (!v.empty())
+				s.push_back(v);
+			val &= ~k;
+		}
+	}
+	auto it = mode_3d_map.find(val & DRM_MODE_FLAG_3D_MASK);
+	if (it != mode_3d_map.end()) {
+		if (!it->second.empty())
+			s.push_back(it->second);
+		val &= ~DRM_MODE_FLAG_3D_MASK;
+	}
+	it = mode_aspect_map.find(val & DRM_MODE_FLAG_PIC_AR_MASK);
+	if (it != mode_aspect_map.end()) {
+		if (!it->second.empty())
+			s.push_back(it->second);
+		val &= ~DRM_MODE_FLAG_PIC_AR_MASK;
+	}
+	// any unknown bits
+	if (val != 0)
+		s.push_back(fmt::format("{:#x}", val));
+	return join(s, "|");
+}
+
 string Videomode::to_string_long() const
 {
 	string h = fmt::format("{}/{}/{}/{}/{}", hdisplay, hfp(), hsw(), hbp(), sync_to_char(hsync()));
 	string v = fmt::format("{}/{}/{}/{}/{}", vdisplay, vfp(), vsw(), vbp(), sync_to_char(vsync()));
 
-	string str = fmt::format("{} {:.3f} {} {} {} ({:.2f}) {:#x} {:#x}",
+	string str = fmt::format("{} {:.3f} {} {} {} ({:.2f}) {} {}",
 				 to_string_short(),
 				 clock / 1000.0,
 				 h, v,
 				 vrefresh, calculated_vrefresh(),
-				 flags,
-				 type);
+				 mode_type_str(type),
+				 mode_flag_str(flags));
 
 	return str;
 }
@@ -131,13 +236,13 @@ string Videomode::to_string_long_padded() const
 	string h = fmt::format("{}/{}/{}/{}/{}", hdisplay, hfp(), hsw(), hbp(), sync_to_char(hsync()));
 	string v = fmt::format("{}/{}/{}/{}/{}", vdisplay, vfp(), vsw(), vbp(), sync_to_char(vsync()));
 
-	string str = fmt::format("{:<16} {:7.3f} {:<18} {:<18} {:2} ({:.2f}) {:#10x} {:#6x}",
+	string str = fmt::format("{:<16} {:7.3f} {:<18} {:<18} {:2} ({:.2f}) {:<5} {}",
 				 to_string_short(),
 				 clock / 1000.0,
 				 h, v,
 				 vrefresh, calculated_vrefresh(),
-				 flags,
-				 type);
+				 mode_type_str(type),
+				 mode_flag_str(flags));
 
 	return str;
 }