feat: support DRM as display driver

README.md

@@ -98,12 +98,16 @@ You may override the defaults. In most cases, though, you won't need to do so:
     TSLIB_PLUGINDIR         Plugin directory.
                             Default:                ${datadir}/plugins
 
-    TSLIB_CONSOLEDEVICE     Console device. (not needed when using --with-sdl2)
+    TSLIB_CONSOLEDEVICE     Console device. (not needed when using --with-sdl2
+                            or --with-drm)
                             Default:                /dev/tty
 
-    TSLIB_FBDEVICE          Framebuffer device.
+    TSLIB_FBDEVICE          Framebuffer device. (not needed when using --with-drm)
                             Default:                /dev/fb0
 
+    TSLIB_DRMDEVICE         DRM device. (only when built with --with-drm)
+                            Default:                /dev/dri/card0
+
 ### use the filtered result in your system (X.org method)
 If you're using X.org graphical X server, things should be very easy. Install
 tslib and [xf86-input-tslib](https://github.com/merge/xf86-input-tslib),
@@ -648,6 +652,7 @@ compatibility.
 
 * libc (with libdl only when building dynamically linked)
 * libsdl2-dev (only when using `--with-sdl2` for [SDL2](https://www.libsdl.org/) graphical applications)
+* libdrm-dev (only when using `--with-drm` for DRM/KMS graphical applications)
 
 ### related libraries
 
@@ -773,6 +778,15 @@ implementation of the necessary graphical tools using SDL2. They are more portab
 but require more resources to run. To use them, make sure you have SDL2 and the
 development headers installed and use `./configure --with-sdl2`.
 
+### DRM/KMS support for graphical tools
+
+On systems without a framebuffer device (`/dev/fb0`), graphical tools like
+`ts_calibrate`, `ts_test`, and `ts_test_mt` can be built to use DRM/KMS
+instead. This uses libdrm with dumb buffers for direct rendering. To use this,
+make sure you have libdrm and the development headers installed and use
+`./configure --with-drm`. The DRM device can be configured via the
+`TSLIB_DRMDEVICE` environment variable (default: `/dev/dri/card0`).
+
 ### portability
 
 tslib is cross-platform; you should be able to build it on a large variety of

configure.ac

@@ -181,6 +181,17 @@ AS_IF([test "x$with_sdl2" = "xyes"], [
   AC_CHECK_LIB([SDL2], [SDL_Init], [], [exit 1])
 ])
 
+AC_ARG_WITH(drm,
+  [AS_HELP_STRING([--with-drm], [build graphical tools using DRM/KMS instead of fbdev])],
+  [with_drm=$withval],
+  [with_drm=no])
+
+AM_CONDITIONAL(DRM, test x"$with_drm" = "xyes")
+AS_IF([test "x$with_drm" = "xyes"], [
+  AC_DEFINE(HAVE_LIBDRM, 1, [Use libdrm for graphical tools.])
+  PKG_CHECK_MODULES([LIBDRM], [libdrm], [], [AC_MSG_ERROR([libdrm not found])])
+])
+
 # libts Library versioning
 # increment if the interface changed
 LT_CURRENT=10

doc/ts.conf.5

@@ -65,6 +65,7 @@ We try to open /dev/input/ts, /dev/input/touchscreen and /dev/touchscreen/ucb1x0
 \fBTSLIB_CONSOLEDEVICE\fR
 .RS 4
 Tslib default console device\&.
+Not needed when using \-\-with\-sdl2 or \-\-with\-drm\&.
 .sp
 Default:
 /dev/tty
@@ -92,11 +93,21 @@ Default;
 \fBTSLIB_FBDEVICE\fR
 .RS 4
 Framebuffer device to use for the touchscreen support\&.
+Not used when built with \-\-with\-drm\&.
 .sp
 Default:
 /dev/fb0\&.
 .RE
 .PP
+\fBTSLIB_DRMDEVICE\fR
+.RS 4
+DRM device to use for the touchscreen support\&.
+Only used when built with \-\-with\-drm\&.
+.sp
+Default:
+/dev/dri/card0\&.
+.RE
+.PP
 \fBTSLIB_PLUGINDIR\fR
 .RS 4
 Plugin directory for tslib\&.

tests/CMakeLists.txt

@@ -10,11 +10,17 @@
 
 
 option(with-sdl "build graphical tools like ts_calibrate using SDL" OFF)
+option(with-drm "build graphical tools using DRM/KMS instead of fbdev" OFF)
 
 if (${with-sdl})
 	find_package(SDL2 REQUIRED)
 endif()
 
+if (${with-drm})
+	find_package(PkgConfig REQUIRED)
+	pkg_check_modules(LIBDRM REQUIRED libdrm)
+endif()
+
 function(TSLIB_ADD_TEST_ON_PLATFORMS test_name)
 	foreach(condition IN LISTS ARGN)
 		if (${condition})
@@ -23,15 +29,23 @@ function(TSLIB_ADD_TEST_ON_PLATFORMS test_name)
 			if (${with-sdl})
 				target_link_libraries(${test_name} PUBLIC SDL2)
 			endif()
+			if (${with-drm})
+				target_include_directories(${test_name} PRIVATE ${LIBDRM_INCLUDE_DIRS})
+				target_link_libraries(${test_name} PUBLIC ${LIBDRM_LIBRARIES})
+			endif()
 			set(tslib_tests ${tslib_tests} ${test_name} PARENT_SCOPE)
 			break()
 		endif()
 	endforeach()
 endfunction(TSLIB_ADD_TEST_ON_PLATFORMS)
 
 
-set(fbutils $<$<PLATFORM_ID:FreeBSD>:fbutils-bsd.c>
-	    $<$<PLATFORM_ID:Linux>:fbutils-linux.c>)
+if (${with-drm})
+	set(fbutils fbutils-drm.c)
+else()
+	set(fbutils $<$<PLATFORM_ID:FreeBSD>:fbutils-bsd.c>
+		    $<$<PLATFORM_ID:Linux>:fbutils-linux.c>)
+endif()
 
 
 if(${with-sdl})

tests/Makefile.am

@@ -47,24 +47,36 @@ endif
 
 ts_test_SOURCES		= ts_test.c testutils.c testutils.h fbutils.h font_8x8.c font_8x16.c font.h
 ts_test_LDADD		= $(top_builddir)/src/libts.la $(LIBEVDEV_LIBS)
+if DRM
+ts_test_SOURCES		+= fbutils-drm.c
+ts_test_CFLAGS		= $(AM_CFLAGS) $(LIBDRM_CFLAGS)
+ts_test_LDADD		+= $(LIBDRM_LIBS)
+else
 if FREEBSD
 ts_test_SOURCES		+= fbutils-bsd.c
 else
 ts_test_SOURCES		+= fbutils-linux.c
 endif
+endif
 
 if SDL
 ts_test_mt_SOURCES	= ts_test_mt_sdl.c sdlutils.c sdlutils.h
 ts_test_mt_LDADD	= $(top_builddir)/src/libts.la -lSDL2 $(LIBEVDEV_LIBS)
 else
 ts_test_mt_SOURCES	= ts_test_mt.c testutils.c testutils.h fbutils.h font_8x8.c font_8x16.c font.h
 ts_test_mt_LDADD	= $(top_builddir)/src/libts.la $(LIBEVDEV_LIBS)
+if DRM
+ts_test_mt_SOURCES	+= fbutils-drm.c
+ts_test_mt_CFLAGS	= $(AM_CFLAGS) $(LIBDRM_CFLAGS)
+ts_test_mt_LDADD	+= $(LIBDRM_LIBS)
+else
 if FREEBSD
 ts_test_mt_SOURCES	+= fbutils-bsd.c
 else
 ts_test_mt_SOURCES	+= fbutils-linux.c
 endif
 endif
+endif
 
 ts_print_SOURCES	= ts_print.c
 ts_print_LDADD		= $(top_builddir)/src/libts.la $(LIBEVDEV_LIBS)
@@ -84,20 +96,32 @@ ts_calibrate_LDADD	= $(top_builddir)/src/libts.la -lSDL2 $(LIBEVDEV_LIBS)
 else
 ts_calibrate_SOURCES	= ts_calibrate.c ts_calibrate.h ts_calibrate_common.c fbutils.h testutils.c testutils.h font_8x8.c font_8x16.c font.h
 ts_calibrate_LDADD	= $(top_builddir)/src/libts.la $(LIBEVDEV_LIBS)
+if DRM
+ts_calibrate_SOURCES	+= fbutils-drm.c
+ts_calibrate_CFLAGS	= $(AM_CFLAGS) $(LIBDRM_CFLAGS)
+ts_calibrate_LDADD	+= $(LIBDRM_LIBS)
+else
 if FREEBSD
 ts_calibrate_SOURCES	+= fbutils-bsd.c
 else
 ts_calibrate_SOURCES	+= fbutils-linux.c
 endif
 endif
+endif
 
 ts_harvest_SOURCES	= ts_harvest.c fbutils.h testutils.c testutils.h font_8x8.c font_8x16.c font.h
 ts_harvest_LDADD	= $(top_builddir)/src/libts.la $(LIBEVDEV_LIBS)
+if DRM
+ts_harvest_SOURCES	+= fbutils-drm.c
+ts_harvest_CFLAGS	= $(AM_CFLAGS) $(LIBDRM_CFLAGS)
+ts_harvest_LDADD	+= $(LIBDRM_LIBS)
+else
 if FREEBSD
 ts_harvest_SOURCES	+= fbutils-bsd.c
 else
 ts_harvest_SOURCES	+= fbutils-linux.c
 endif
+endif
 
 ts_finddev_SOURCES      = ts_finddev.c
 ts_finddev_LDADD        = $(top_builddir)/src/libts.la $(LIBEVDEV_LIBS)