3 files changed, 266 insertions, 0 deletions
diff --git a/include/backend/drm-properties.h b/include/backend/drm-properties.h
new file mode 100644
index 00000000..287fc1e0
--- /dev/null
+++ b/include/backend/drm-properties.h
@@ -0,0 +1,62 @@
+#ifndef DRM_PROPERTIES_H
+#define DRM_PROPERTIES_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+/*
+ * These types contain the property ids for several DRM objects.
+ * See https://01.org/linuxgraphics/gfx-docs/drm/gpu/drm-kms.html#kms-properties
+ * for more details.
+ */
+
+union wlr_drm_connector_props {
+	struct {
+		uint32_t edid;
+		uint32_t dpms;
+
+		// atomic-modesetting only
+
+		uint32_t crtc_id;
+	};
+	uint32_t props[3];
+};
+
+union wlr_drm_crtc_props {
+	struct {
+		// Neither of these are guranteed to exist
+		uint32_t rotation;
+		uint32_t scaling_mode;
+	};
+	uint32_t props[2];
+};
+
+union wlr_drm_plane_props {
+	struct {
+		uint32_t type;
+		uint32_t rotation; // Not guranteed to exist
+
+		// atomic-modesetting only
+
+		uint32_t src_x;
+		uint32_t src_y;
+		uint32_t src_w;
+		uint32_t src_h;
+		uint32_t crtc_x;
+		uint32_t crtc_y;
+		uint32_t crtc_w;
+		uint32_t crtc_h;
+		uint32_t fb_id;
+		uint32_t crtc_id;
+	};
+	uint32_t props[12];
+};
+
+bool wlr_drm_get_connector_props(int fd, uint32_t id, union wlr_drm_connector_props *out);
+bool wlr_drm_get_crtc_props(int fd, uint32_t id, union wlr_drm_crtc_props *out);
+bool wlr_drm_get_plane_props(int fd, uint32_t id, union wlr_drm_plane_props *out);
+
+bool wlr_drm_get_prop(int fd, uint32_t obj, uint32_t prop, uint64_t *ret);
+void *wlr_drm_get_prop_blob(int fd, uint32_t obj, uint32_t prop, size_t *ret_len);
+
+#endif
diff --git a/include/backend/drm-util.h b/include/backend/drm-util.h
new file mode 100644
index 00000000..759bdb48
--- /dev/null
+++ b/include/backend/drm-util.h
@@ -0,0 +1,37 @@
+#ifndef WLR_DRM_UTIL_H
+#define WLR_DRM_UTIL_H
+
+#include <stdint.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+#include <wlr/types/wlr_output.h>
+
+// Calculates a more accurate refresh rate (mHz) than what mode itself provides
+int32_t calculate_refresh_rate(drmModeModeInfo *mode);
+// Populates the make/model/phys_{width,height} of output from the edid data
+void parse_edid(struct wlr_output *restrict output, size_t len, const uint8_t *data);
+// Returns the string representation of a DRM output type
+const char *conn_get_name(uint32_t type_id);
+
+// Part of match_obj
+enum {
+	UNMATCHED = (uint32_t)-1,
+	SKIP = (uint32_t)-2,
+};
+
+/*
+ * Tries to match some DRM objects with some other DRM resource.
+ * e.g. Match CRTCs with Encoders, CRTCs with Planes.
+ *
+ * objs contains a bit array which resources it can be matched with.
+ * e.g. Bit 0 set means can be matched with res[0]
+ *
+ * res contains an index of which objs it is matched with or UNMATCHED.
+ *
+ * This solution is left in out.
+ * Returns the total number of matched solutions.
+ */
+size_t match_obj(size_t num_objs, const uint32_t objs[static restrict num_objs],
+		size_t num_res, const uint32_t res[static restrict num_res],
+		uint32_t out[static restrict num_res]);
+#endif
diff --git a/include/backend/drm.h b/include/backend/drm.h
new file mode 100644
index 00000000..91346169
--- /dev/null
+++ b/include/backend/drm.h
@@ -0,0 +1,167 @@
+#ifndef DRM_BACKEND_H
+#define DRM_BACKEND_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <wayland-server.h>
+#include <xf86drmMode.h>
+#include <EGL/egl.h>
+#include <libudev.h>
+#include <gbm.h>
+
+#include <wlr/backend/session.h>
+#include <wlr/backend/drm.h>
+#include <wlr/util/list.h>
+
+#include <backend/egl.h>
+#include <backend/udev.h>
+#include "drm-properties.h"
+
+struct wlr_drm_plane {
+	uint32_t type;
+	uint32_t id;
+
+	uint32_t possible_crtcs;
+
+	uint32_t width, height;
+
+	struct gbm_surface *gbm;
+	EGLSurface egl;
+
+	struct gbm_bo *front;
+	struct gbm_bo *back;
+
+	// Only used by cursor
+	float matrix[16];
+	struct wlr_renderer *wlr_rend;
+	struct wlr_surface *wlr_surf;
+
+	union wlr_drm_plane_props props;
+};
+
+struct wlr_drm_crtc {
+	uint32_t id;
+	union {
+		struct {
+			struct wlr_drm_plane *overlay;
+			struct wlr_drm_plane *primary;
+			struct wlr_drm_plane *cursor;
+		};
+		struct wlr_drm_plane *planes[3];
+	};
+
+	union wlr_drm_crtc_props props;
+
+	struct wl_list connectors;
+};
+
+struct wlr_drm_connector {
+	struct wlr_output *base;
+	uint32_t id;
+	struct wlr_drm_crtc *crtc;
+
+	union wlr_drm_connector_props props;
+
+	struct wl_list link;
+};
+
+struct wlr_drm_renderer {
+	int fd;
+	struct gbm_device *gbm;
+	struct wlr_egl egl;
+};
+
+bool wlr_drm_renderer_init(struct wlr_drm_renderer *renderer, int fd);
+void wlr_drm_renderer_free(struct wlr_drm_renderer *renderer);
+
+struct wlr_backend_state {
+	struct wlr_backend *base;
+
+	int fd;
+	dev_t dev;
+
+	size_t num_crtcs;
+	struct wlr_drm_crtc *crtcs;
+	size_t num_planes;
+	struct wlr_drm_plane *planes;
+
+	union {
+		struct {
+			size_t num_overlay_planes;
+			size_t num_primary_planes;
+			size_t num_cursor_planes;
+		};
+		size_t num_type_planes[3];
+	};
+
+	union {
+		struct {
+			struct wlr_drm_plane *overlay_planes;
+			struct wlr_drm_plane *primary_planes;
+			struct wlr_drm_plane *cursor_planes;
+		};
+		struct wlr_drm_plane *type_planes[3];
+	};
+
+	struct wl_display *display;
+	struct wl_event_source *drm_event;
+
+	struct wl_listener session_signal;
+	struct wl_listener drm_invalidated;
+
+	uint32_t taken_crtcs;
+	list_t *outputs;
+
+	struct wlr_drm_renderer renderer;
+	struct wlr_session *session;
+	struct wlr_udev *udev;
+};
+
+enum wlr_drm_output_state {
+	WLR_DRM_OUTPUT_DISCONNECTED,
+	WLR_DRM_OUTPUT_NEEDS_MODESET,
+	WLR_DRM_OUTPUT_CONNECTED,
+};
+
+struct wlr_output_mode_state {
+	struct wlr_wl_output_mode *wlr_mode;
+	drmModeModeInfo mode;
+};
+
+struct wlr_output_state {
+	struct wlr_output *base;
+	enum wlr_drm_output_state state;
+	uint32_t connector;
+
+	struct wlr_drm_crtc *crtc;
+	uint32_t possible_crtc;
+
+	union wlr_drm_connector_props props;
+
+	uint32_t width;
+	uint32_t height;
+
+	drmModeCrtc *old_crtc;
+
+	struct wlr_drm_renderer *renderer;
+	struct gbm_bo *bo[2];
+	struct gbm_bo *cursor_bo[2];
+	int current_cursor;
+	uint32_t cursor_width, cursor_height;
+
+	bool pageflip_pending;
+};
+
+bool wlr_drm_check_features(struct wlr_backend_state *drm);
+bool wlr_drm_resources_init(struct wlr_backend_state *drm);
+void wlr_drm_resources_free(struct wlr_backend_state *drm);
+void wlr_drm_output_cleanup(struct wlr_output_state *output, bool restore);
+
+void wlr_drm_scan_connectors(struct wlr_backend_state *state);
+int wlr_drm_event(int fd, uint32_t mask, void *data);
+
+void wlr_drm_output_start_renderer(struct wlr_output_state *output);
+bool wlr_drm_crtc_set_cursor(struct wlr_backend_state *drm, struct wlr_drm_crtc *crtc);
+
+#endif