lvgl: lvgl-demo-fb: Switch to CMake and add DRM and SDL support

Switch the build of this recipe to CMake from the horrible Makefile
which is still part of the source tree and which blatantly encodes
various CFLAGS and co.

Add support for use of DRM and SDL backends and make this configurable.
The FBDEV is deprecated for close to two decades, so provide modern
alternatives -- DRM and SDL.

The DRM uses modern DRM API, but there is no GPU acceleration.
The SDL provides GPU support abstracted via the libSDL2 API and
can use multiple backends, DRM and WL included.

Default to the DRM backend, because FBDEV is just bad for any modern system.

Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

1 files changed, 45 insertions, 5 deletions

diff --git a/meta-oe/recipes-graphics/lvgl/lvgl-demo-fb_8.3.0.bb b/meta-oe/recipes-graphics/lvgl/lvgl-demo-fb_8.3.0.bb
index 1dfb199ff..33e7c94e6 100644
--- a/meta-oe/recipes-graphics/lvgl/lvgl-demo-fb_8.3.0.bb
+++ b/meta-oe/recipes-graphics/lvgl/lvgl-demo-fb_8.3.0.bb
@@ -8,14 +8,54 @@ LIC_FILES_CHKSUM = "file://LICENSE;md5=802d3d83ae80ef5f343050bf96cce3a4 \
 SRC_URI = "gitsm://github.com/lvgl/lv_port_linux_frame_buffer.git;branch=master;protocol=https"
 SRCREV = "adf2c4490e17a1b9ec1902cc412a24b3b8235c8e"
 
+EXTRA_OEMAKE = "DESTDIR=${D}"
+
+PACKAGECONFIG ??= "drm"
+PACKAGECONFIG[drm] = ",,libdrm"
+PACKAGECONFIG[fbdev] = ",,"
+PACKAGECONFIG[sdl] = ",,virtual/libsdl2"
+LVGL_CONFIG_USE_DRM = "${@bb.utils.contains('PACKAGECONFIG', 'drm', '1', '0', d)}"
+LVGL_CONFIG_DRM_CARD ?= "/dev/dri/card0"
+LVGL_CONFIG_USE_FBDEV = "${@bb.utils.contains('PACKAGECONFIG', 'fbdev', '1', '0', d)}"
+LVGL_CONFIG_USE_SDL = "${@bb.utils.contains('PACKAGECONFIG', 'sdl', '1', '0', d)}"
+
+inherit cmake
+
 S = "${WORKDIR}/git"
 
-REQUIRED_DISTRO_FEATURES = "fbdev"
+EXTRA_OECMAKE += "-Dinstall:BOOL=ON -DLIB_INSTALL_DIR=${baselib}"
+TARGET_CFLAGS += "-I${STAGING_INCDIR}/libdrm"
 
-inherit features_check
+do_configure:prepend() {
+        sed -i -e "s|\(^#  define USE_FBDEV \).*|#  define USE_FBDEV ${LVGL_CONFIG_USE_FBDEV}|g" \
+                -e "s|\(^#  define USE_DRM \).*|#  define USE_DRM ${LVGL_CONFIG_USE_DRM}|g" \
+                -e "s|\(^#  define DRM_CARD \).*|#  define DRM_CARD \"${LVGL_CONFIG_DRM_CARD}\"|g" \
+                -e "s|\(^# define USE_SDL \).*|#  define USE_SDL ${LVGL_CONFIG_USE_SDL}|g" \
+                -e "s|\(^#  define USE_SDL_GPU \).*|#  define USE_SDL_GPU 1|g" \
+                -e "s|\(^#  define SDL_DOUBLE_BUFFERED \).*|#  define SDL_DOUBLE_BUFFERED 1|g" \
+        "${S}/lv_drv_conf.h"
 
-EXTRA_OEMAKE = "DESTDIR=${D}"
+        if [ "${LVGL_CONFIG_USE_DRM}" -eq 1 ] ; then
+                # Add libdrm build dependency
+                sed -i '/^target_link_libraries/ s@lvgl::drivers@& drm@' "${S}/CMakeLists.txt"
+                # Switch from fbdev to drm usage
+                sed -i 's@fbdev@drm@g' "${S}/main.c"
+                # Pull resolution from DRM instead of hardcoding it
+                sed -i '/disp_drv.hor_res/ d' "${S}/main.c"
+                sed -i '/disp_drv.ver_res/ s@disp_drv.ver_res.*@drm_get_sizes(\&disp_drv.hor_res, \&disp_drv.ver_res, NULL);@' "${S}/main.c"
+        fi
+
+        if [ "${LVGL_CONFIG_USE_SDL}" -eq 1 ] ; then
+                # Add libsdl build dependency
+                sed -i '/^target_link_libraries/ s@lvgl::drivers@& SDL2@' "${S}/CMakeLists.txt"
+                # Switch from fbdev to sdl usage
+                sed -i 's@fbdev_flush@sdl_display_flush@g' "${S}/main.c"
+                sed -i 's@lv_drivers/display/fbdev.h@lv_drivers/sdl/sdl.h@g' "${S}/main.c"
+                sed -i 's@fbdev@sdl@g' "${S}/main.c"
+        fi
+}
 
-do_install() {
-        oe_runmake install
+do_install:append() {
+        install -d ${D}${bindir}
+        install -m 0755 ${B}/lvgl_fb ${D}${bindir}/
 }