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-rw-r--r--backend/drm/drm.c466
-rw-r--r--backend/drm/drm.h54
-rw-r--r--backend/drm/event.c91
-rw-r--r--backend/drm/event.h21
-rw-r--r--backend/drm/main.c160
-rw-r--r--backend/drm/otd.c71
-rw-r--r--backend/drm/otd.h44
-rw-r--r--backend/drm/session.c224
-rw-r--r--backend/drm/session.h25
-rw-r--r--backend/drm/udev.c158
-rw-r--r--backend/drm/udev.h9
11 files changed, 1323 insertions, 0 deletions
diff --git a/backend/drm/drm.c b/backend/drm/drm.c
new file mode 100644
index 00000000..bb6359c5
--- /dev/null
+++ b/backend/drm/drm.c
@@ -0,0 +1,466 @@
+#include "otd.h"
+#include "drm.h"
+#include "event.h"
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <inttypes.h>
+#include <errno.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+#include <drm_mode.h>
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+#include <gbm.h>
+#include <GLES3/gl3.h>
+
+static const char *conn_name[] = {
+ [DRM_MODE_CONNECTOR_Unknown] = "Unknown",
+ [DRM_MODE_CONNECTOR_VGA] = "VGA",
+ [DRM_MODE_CONNECTOR_DVII] = "DVI-I",
+ [DRM_MODE_CONNECTOR_DVID] = "DVI-D",
+ [DRM_MODE_CONNECTOR_DVIA] = "DVI-A",
+ [DRM_MODE_CONNECTOR_Composite] = "Composite",
+ [DRM_MODE_CONNECTOR_SVIDEO] = "SVIDEO",
+ [DRM_MODE_CONNECTOR_LVDS] = "LVDS",
+ [DRM_MODE_CONNECTOR_Component] = "Component",
+ [DRM_MODE_CONNECTOR_9PinDIN] = "DIN",
+ [DRM_MODE_CONNECTOR_DisplayPort] = "DP",
+ [DRM_MODE_CONNECTOR_HDMIA] = "HDMI-A",
+ [DRM_MODE_CONNECTOR_HDMIB] = "HDMI-B",
+ [DRM_MODE_CONNECTOR_TV] = "TV",
+ [DRM_MODE_CONNECTOR_eDP] = "eDP",
+ [DRM_MODE_CONNECTOR_VIRTUAL] = "Virtual",
+ [DRM_MODE_CONNECTOR_DSI] = "DSI",
+};
+
+// EGL extensions
+PFNEGLGETPLATFORMDISPLAYEXTPROC get_platform_display;
+PFNEGLCREATEPLATFORMWINDOWSURFACEEXTPROC create_platform_window_surface;
+
+static bool egl_exts()
+{
+ get_platform_display = (PFNEGLGETPLATFORMDISPLAYEXTPROC)
+ eglGetProcAddress("eglGetPlatformDisplayEXT");
+
+ create_platform_window_surface = (PFNEGLCREATEPLATFORMWINDOWSURFACEEXTPROC)
+ eglGetProcAddress("eglCreatePlatformWindowSurfaceEXT");
+
+ return get_platform_display && create_platform_window_surface;
+}
+
+bool egl_get_config(EGLDisplay disp, EGLConfig *out)
+{
+ EGLint count = 0, matched = 0, ret;
+
+ ret = eglGetConfigs(disp, NULL, 0, &count);
+ if (ret == EGL_FALSE || count == 0) {
+ return false;
+ }
+
+ EGLConfig configs[count];
+
+ ret = eglChooseConfig(disp, NULL, configs, count, &matched);
+ if (ret == EGL_FALSE) {
+ return false;
+ }
+
+ for (int i = 0; i < matched; ++i) {
+ EGLint gbm_format;
+
+ if (!eglGetConfigAttrib(disp,
+ configs[i],
+ EGL_NATIVE_VISUAL_ID,
+ &gbm_format))
+ continue;
+
+ if (gbm_format == GBM_FORMAT_XRGB8888) {
+ *out = configs[i];
+ return true;
+ }
+ }
+
+ return false;
+}
+
+bool init_renderer(struct otd *otd)
+{
+ if (!egl_exts()) {
+ fprintf(stderr, "Could not get EGL extensions\n");
+ return false;
+ }
+
+ otd->gbm = gbm_create_device(otd->fd);
+ if (!otd->gbm) {
+ fprintf(stderr, "Could not create gbm device: %s\n", strerror(errno));
+ return false;
+ }
+
+ if (eglBindAPI(EGL_OPENGL_ES_API) == EGL_FALSE) {
+ fprintf(stderr, "Could not bind GLES3 API\n");
+ goto error_gbm;
+ }
+
+ otd->egl.disp = get_platform_display(EGL_PLATFORM_GBM_MESA, otd->gbm, NULL);
+ if (otd->egl.disp == EGL_NO_DISPLAY) {
+ fprintf(stderr, "Could not create EGL display\n");
+ goto error_gbm;
+ }
+
+ if (eglInitialize(otd->egl.disp, NULL, NULL) == EGL_FALSE) {
+ fprintf(stderr, "Could not initalise EGL\n");
+ goto error_egl;
+ }
+
+ if (!egl_get_config(otd->egl.disp, &otd->egl.conf)) {
+ fprintf(stderr, "Could not get EGL config\n");
+ goto error_egl;
+ }
+
+ static const EGLint attribs[] = {EGL_CONTEXT_CLIENT_VERSION, 3, EGL_NONE};
+ otd->egl.context = eglCreateContext(otd->egl.disp, otd->egl.conf, EGL_NO_CONTEXT, attribs);
+ if (otd->egl.context == EGL_NO_CONTEXT) {
+ fprintf(stderr, "Could not create EGL context\n");
+ goto error_egl;
+ }
+
+ return true;
+
+error_egl:
+ eglTerminate(otd->egl.disp);
+ eglReleaseThread();
+ eglMakeCurrent(EGL_NO_DISPLAY, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
+
+error_gbm:
+ gbm_device_destroy(otd->gbm);
+
+ return false;
+}
+
+void destroy_renderer(struct otd *otd)
+{
+ if (!otd)
+ return;
+
+ eglDestroyContext(otd->egl.disp, otd->egl.context);
+ eglTerminate(otd->egl.disp);
+ eglReleaseThread();
+ eglMakeCurrent(EGL_NO_DISPLAY, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
+
+ gbm_device_destroy(otd->gbm);
+}
+
+void scan_connectors(struct otd *otd)
+{
+ drmModeRes *res = drmModeGetResources(otd->fd);
+ if (!res)
+ return;
+
+ // I don't know if this needs to be allocated with realloc like this,
+ // as it may not even be possible for the number of connectors to change.
+ // I'll just have to see how DisplayPort MST works with DRM.
+ if ((size_t)res->count_connectors > otd->display_len) {
+ struct otd_display *new = realloc(otd->displays, sizeof *new * res->count_connectors);
+ if (!new)
+ goto error;
+
+ for (int i = otd->display_len; i < res->count_connectors; ++i) {
+ new[i] = (struct otd_display) {
+ .state = OTD_DISP_INVALID,
+ .otd = otd,
+ };
+ }
+
+ otd->display_len = res->count_connectors;
+ otd->displays = new;
+ }
+
+ for (int i = 0; i < res->count_connectors; ++i) {
+ struct otd_display *disp = &otd->displays[i];
+ drmModeConnector *conn = drmModeGetConnector(otd->fd, res->connectors[i]);
+ if (!conn)
+ continue;
+
+ if (otd->displays[i].state == OTD_DISP_INVALID) {
+ disp->state = OTD_DISP_DISCONNECTED;
+ disp->connector = res->connectors[i];
+ snprintf(disp->name, sizeof disp->name, "%s-%"PRIu32,
+ conn_name[conn->connector_type],
+ conn->connector_type_id);
+ }
+
+ if (disp->state == OTD_DISP_DISCONNECTED &&
+ conn->connection == DRM_MODE_CONNECTED) {
+ disp->state = OTD_DISP_NEEDS_MODESET;
+ event_add(otd, disp, OTD_EV_DISPLAY_ADD);
+
+ } else if (disp->state == OTD_DISP_CONNECTED &&
+ conn->connection != DRM_MODE_CONNECTED) {
+ disp->state = OTD_DISP_DISCONNECTED;
+ event_add(otd, disp, OTD_EV_DISPLAY_REM);
+ }
+
+ drmModeFreeConnector(conn);
+ }
+
+error:
+ drmModeFreeResources(res);
+}
+
+static void free_fb(struct gbm_bo *bo, void *data)
+{
+ uint32_t *id = data;
+
+ if (id && *id)
+ drmModeRmFB(gbm_bo_get_fd(bo), *id);
+
+ free(id);
+}
+
+static uint32_t get_fb_for_bo(int fd, struct gbm_bo *bo)
+{
+ uint32_t *id = gbm_bo_get_user_data(bo);
+
+ if (id)
+ return *id;
+
+ id = calloc(1, sizeof *id);
+ if (!id)
+ return 0;
+
+ drmModeAddFB(fd, gbm_bo_get_width(bo), gbm_bo_get_height(bo), 24, 32,
+ gbm_bo_get_stride(bo), gbm_bo_get_handle(bo).u32, id);
+
+ gbm_bo_set_user_data(bo, id, free_fb);
+
+ return *id;
+}
+
+static void init_display_renderer(struct otd *otd, struct otd_display *disp)
+{
+ disp->gbm = gbm_surface_create(otd->gbm,
+ disp->width, disp->height,
+ GBM_FORMAT_XRGB8888,
+ GBM_BO_USE_SCANOUT | GBM_BO_USE_RENDERING);
+ if (!disp->gbm)
+ return;
+
+ disp->egl = create_platform_window_surface(otd->egl.disp, otd->egl.conf,
+ disp->gbm, NULL);
+ if (disp->egl == EGL_NO_SURFACE)
+ return;
+
+ // Render black frame
+
+ eglMakeCurrent(otd->egl.disp, disp->egl, disp->egl, otd->egl.context);
+
+ glViewport(0, 0, disp->width, disp->height);
+ glClearColor(0.0, 0.0, 0.0, 1.0);
+ glClear(GL_COLOR_BUFFER_BIT);
+
+ eglSwapBuffers(otd->egl.disp, disp->egl);
+
+ struct gbm_bo *bo = gbm_surface_lock_front_buffer(disp->gbm);
+ uint32_t fb_id = get_fb_for_bo(otd->fd, bo);
+
+ drmModeSetCrtc(otd->fd, disp->crtc, fb_id, 0, 0,
+ &disp->connector, 1, disp->active_mode);
+ drmModePageFlip(otd->fd, disp->crtc, fb_id, DRM_MODE_PAGE_FLIP_EVENT, disp);
+
+ gbm_surface_release_buffer(disp->gbm, bo);
+}
+
+static drmModeModeInfo *select_mode(size_t num_modes,
+ drmModeModeInfo modes[static num_modes],
+ drmModeCrtc *old_crtc,
+ const char *str)
+{
+ if (strcmp(str, "preferred") == 0)
+ return &modes[0];
+
+ if (strcmp(str, "current") == 0) {
+ if (!old_crtc) {
+ fprintf(stderr, "Display does not have currently configured mode\n");
+ return NULL;
+ }
+
+ for (size_t i = 0; i < num_modes; ++i) {
+ if (memcmp(&modes[i], &old_crtc->mode, sizeof modes[0]) == 0)
+ return &modes[i];
+ }
+
+ // We should never get here
+ assert(0);
+ }
+
+ unsigned width = 0;
+ unsigned height = 0;
+ unsigned rate = 0;
+ int ret;
+
+ if ((ret = sscanf(str, "%ux%u@%u", &width, &height, &rate)) != 2 && ret != 3) {
+ fprintf(stderr, "Invalid modesetting string\n");
+ return NULL;
+ }
+
+ for (size_t i = 0; i < num_modes; ++i) {
+ if (modes[i].hdisplay == width &&
+ modes[i].vdisplay == height &&
+ (!rate || modes[i].vrefresh == rate))
+ return &modes[i];
+ }
+
+ return NULL;
+}
+
+bool modeset_str(struct otd *otd, struct otd_display *disp, const char *str)
+{
+ drmModeConnector *conn = drmModeGetConnector(otd->fd, disp->connector);
+ if (!conn || conn->connection != DRM_MODE_CONNECTED || conn->count_modes == 0)
+ goto error;
+
+ disp->num_modes = conn->count_modes;
+ disp->modes = malloc(sizeof *disp->modes * disp->num_modes);
+ if (!disp->modes)
+ goto error;
+ memcpy(disp->modes, conn->modes, sizeof *disp->modes * disp->num_modes);
+
+ drmModeEncoder *curr_enc = drmModeGetEncoder(otd->fd, conn->encoder_id);
+ if (curr_enc) {
+ disp->old_crtc = drmModeGetCrtc(otd->fd, curr_enc->crtc_id);
+ free(curr_enc);
+ }
+
+ disp->active_mode = select_mode(disp->num_modes, disp->modes, disp->old_crtc, str);
+ if (!disp->active_mode) {
+ fprintf(stderr, "Could not find mode '%s' for %s\n", str, disp->name);
+ goto error;
+ }
+
+ fprintf(stderr, "Configuring %s with mode %ux%u@%u\n",
+ disp->name, disp->active_mode->hdisplay, disp->active_mode->vdisplay,
+ disp->active_mode->vrefresh);
+
+ drmModeRes *res = drmModeGetResources(otd->fd);
+ if (!res)
+ goto error;
+
+ bool success = false;
+ for (int i = 0; !success && i < conn->count_encoders; ++i) {
+ drmModeEncoder *enc = drmModeGetEncoder(otd->fd, conn->encoders[i]);
+ if (!enc)
+ continue;
+
+ for (int j = 0; j < res->count_crtcs; ++j) {
+ if ((enc->possible_crtcs & (1 << j)) == 0)
+ continue;
+
+ if ((otd->taken_crtcs & (1 << j)) == 0) {
+ otd->taken_crtcs |= 1 << j;
+ disp->crtc = res->crtcs[j];
+
+ success = true;
+ break;
+ }
+ }
+
+ drmModeFreeEncoder(enc);
+ }
+
+ drmModeFreeResources(res);
+
+ if (!success)
+ goto error;
+
+ disp->state = OTD_DISP_CONNECTED;
+ drmModeFreeConnector(conn);
+
+ disp->width = disp->active_mode->hdisplay;
+ disp->height = disp->active_mode->vdisplay;
+
+ init_display_renderer(otd, disp);
+
+ return true;
+error:
+ disp->state = OTD_DISP_DISCONNECTED;
+ drmModeFreeConnector(conn);
+
+ event_add(otd, disp, OTD_EV_DISPLAY_REM);
+
+ return false;
+}
+
+
+void page_flip_handler(int fd,
+ unsigned seq,
+ unsigned tv_sec,
+ unsigned tv_usec,
+ void *user)
+{
+ struct otd_display *disp = user;
+
+ disp->pageflip_pending = true;
+ if (!disp->cleanup)
+ event_add(disp->otd, disp, OTD_EV_RENDER);
+}
+
+void destroy_display_renderer(struct otd *otd, struct otd_display *disp)
+{
+ if (!otd || !disp || disp->state != OTD_DISP_CONNECTED)
+ return;
+
+ drmModeCrtc *crtc = disp->old_crtc;
+ if (crtc) {
+ drmEventContext event = {
+ .version = DRM_EVENT_CONTEXT_VERSION,
+ .page_flip_handler = page_flip_handler,
+ };
+
+ disp->cleanup = true;
+ while (disp->pageflip_pending)
+ drmHandleEvent(otd->fd, &event);
+
+ drmModeSetCrtc(otd->fd, crtc->crtc_id, crtc->buffer_id,
+ crtc->x, crtc->y, &disp->connector,
+ 1, &crtc->mode);
+ drmModeFreeCrtc(crtc);
+ }
+
+ eglDestroySurface(otd->egl.disp, disp->egl);
+ gbm_surface_destroy(disp->gbm);
+
+ free(disp->modes);
+}
+
+void get_drm_event(struct otd *otd)
+{
+ drmEventContext event = {
+ .version = DRM_EVENT_CONTEXT_VERSION,
+ .page_flip_handler = page_flip_handler,
+ };
+
+ drmHandleEvent(otd->fd, &event);
+}
+
+void rendering_begin(struct otd_display *disp)
+{
+ struct otd *otd = disp->otd;
+ eglMakeCurrent(otd->egl.disp, disp->egl, disp->egl, otd->egl.context);
+}
+
+void rendering_end(struct otd_display *disp)
+{
+ struct otd *otd = disp->otd;
+ eglSwapBuffers(otd->egl.disp, disp->egl);
+
+ struct gbm_bo *bo = gbm_surface_lock_front_buffer(disp->gbm);
+ uint32_t fb_id = get_fb_for_bo(otd->fd, bo);
+
+ drmModePageFlip(otd->fd, disp->crtc, fb_id, DRM_MODE_PAGE_FLIP_EVENT, disp);
+
+ gbm_surface_release_buffer(disp->gbm, bo);
+
+ disp->pageflip_pending = false;
+}
diff --git a/backend/drm/drm.h b/backend/drm/drm.h
new file mode 100644
index 00000000..8744b440
--- /dev/null
+++ b/backend/drm/drm.h
@@ -0,0 +1,54 @@
+#ifndef DRM_H
+#define DRM_H
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <xf86drmMode.h>
+#include <EGL/egl.h>
+#include <gbm.h>
+
+enum otd_display_state {
+ OTD_DISP_INVALID,
+ OTD_DISP_DISCONNECTED,
+ OTD_DISP_NEEDS_MODESET,
+ OTD_DISP_CONNECTED,
+};
+
+struct otd_display {
+ struct otd *otd;
+
+ enum otd_display_state state;
+ uint32_t connector;
+ char name[16];
+
+ size_t num_modes;
+ drmModeModeInfo *modes;
+ drmModeModeInfo *active_mode;
+
+ uint32_t width;
+ uint32_t height;
+
+ uint32_t crtc;
+ drmModeCrtc *old_crtc;
+
+ struct gbm_surface *gbm;
+ EGLSurface *egl;
+ uint32_t fb_id;
+
+ bool pageflip_pending;
+ bool cleanup;
+};
+
+bool init_renderer(struct otd *otd);
+void destroy_renderer(struct otd *otd);
+
+void scan_connectors(struct otd *otd);
+bool modeset_str(struct otd *otd, struct otd_display *disp, const char *str);
+void destroy_display_renderer(struct otd *otd, struct otd_display *disp);
+
+void get_drm_event(struct otd *otd);
+
+void rendering_begin(struct otd_display *disp);
+void rendering_end(struct otd_display *disp);
+
+#endif
diff --git a/backend/drm/event.c b/backend/drm/event.c
new file mode 100644
index 00000000..f20cb282
--- /dev/null
+++ b/backend/drm/event.c
@@ -0,0 +1,91 @@
+#include "otd.h"
+#include "event.h"
+#include "drm.h"
+#include "udev.h"
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <poll.h>
+
+static inline void event_swap(struct otd_event *a, struct otd_event *b)
+{
+ struct otd_event tmp = *a;
+ *a = *b;
+ *b = tmp;
+}
+
+bool otd_get_event(struct otd *otd, struct otd_event *restrict ret)
+{
+ struct pollfd fds[] = {
+ { .fd = otd->fd, .events = POLLIN },
+ { .fd = otd->udev_fd, .events = POLLIN },
+ };
+
+ while (poll(fds, 2, 0) > 0) {
+ if (fds[0].revents)
+ get_drm_event(otd);
+ if (fds[1].revents)
+ otd_udev_event(otd);
+ }
+
+ if (otd->event_len == 0) {
+ ret->type = OTD_EV_NONE;
+ ret->display = NULL;
+ return false;
+ }
+
+ struct otd_event *ev = otd->events;
+
+ // Downheap
+ *ret = ev[0];
+ ev[0] = ev[--otd->event_len];
+
+ size_t i = 0;
+ while (i < otd->event_len / 2) {
+ size_t left = i * 2 + 1;
+ size_t right = i * 2 + 2;
+ size_t max = (ev[left].type > ev[right].type) ? left : right;
+
+ if (ev[i].type <= ev[max].type) {
+ event_swap(&ev[i], &ev[max]);
+ i = max;
+ } else {
+ break;
+ }
+ }
+
+ return true;
+}
+
+bool event_add(struct otd *otd, struct otd_display *disp, enum otd_event_type type)
+{
+ if (type == OTD_EV_NONE)
+ return true;
+
+ if (otd->event_len == otd->event_cap) {
+ size_t new_size = (otd->event_cap == 0) ? 8 : otd->event_cap * 2;
+
+ struct otd_event *new = realloc(otd->events, sizeof *new * new_size);
+ if (!new) {
+ return false;
+ }
+
+ otd->event_cap = new_size;
+ otd->events = new;
+ }
+
+ struct otd_event *ev = otd->events;
+
+ // Upheap
+ size_t i = otd->event_len++;
+ ev[i].type = type;
+ ev[i].display = disp;
+
+ size_t j;
+ while (i > 0 && ev[i].type > ev[(j = (i - 1) / 2)].type) {
+ event_swap(&ev[i], &ev[j]);
+ i = j;
+ }
+
+ return true;
+}
diff --git a/backend/drm/event.h b/backend/drm/event.h
new file mode 100644
index 00000000..fc4f6f9a
--- /dev/null
+++ b/backend/drm/event.h
@@ -0,0 +1,21 @@
+#ifndef EVENT_H
+#define EVENT_H
+
+#include <stdbool.h>
+
+enum otd_event_type {
+ OTD_EV_NONE,
+ OTD_EV_RENDER,
+ OTD_EV_DISPLAY_REM,
+ OTD_EV_DISPLAY_ADD,
+};
+
+struct otd_event {
+ enum otd_event_type type;
+ struct otd_display *display;
+};
+
+bool otd_get_event(struct otd *otd, struct otd_event *restrict ret);
+bool event_add(struct otd *otd, struct otd_display *disp, enum otd_event_type type);
+
+#endif
diff --git a/backend/drm/main.c b/backend/drm/main.c
new file mode 100644
index 00000000..aab11e19
--- /dev/null
+++ b/backend/drm/main.c
@@ -0,0 +1,160 @@
+#include <stdio.h>
+#include <stdbool.h>
+#include <inttypes.h>
+#include <time.h>
+#include <GLES3/gl3.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdnoreturn.h>
+
+#include "otd.h"
+#include "drm.h"
+#include "event.h"
+
+// I know this is pretty crappy,
+// but it's just for the example's sake
+struct {
+ char *name;
+ char *mode;
+} displays[8];
+int num_displays = 0;
+
+noreturn void usage(const char *name, int ret)
+{
+ fprintf(stderr, "usage: %s [-o <name> [-m <mode>]]*\n"
+ "\n"
+ " -h \tDisplay this help text\n"
+ " -o <name>\tWhich diplay to use. e.g. DVI-I-1.\n"
+ " -m <mode>\tWhich mode to use. It must come after an -o option.\n"
+ " \tMust be either 'preferred', 'current', widthxheight\n"
+ " \tor widthxheight@rate. Defaults to 'preferred'.\n"
+ "\n"
+ "example: %s -o DVI-I-1 -m 1920x1080@60 -o DP-1 -m 1920x1200\n",
+ name, name);
+
+ exit(ret);
+}
+
+void parse_args(int argc, char *argv[])
+{
+ int c;
+ int i = -1;
+
+ while ((c = getopt(argc, argv, "ho:m:")) != -1) {
+ switch (c) {
+ case 'h':
+ usage(argv[0], 0);
+ case 'o':
+ i = num_displays++;
+
+ if (num_displays == 8) {
+ fprintf(stderr, "Too many displays\n");
+ exit(1);
+ }
+
+ displays[i].name = strdup(optarg);
+ break;
+ case 'm':
+ if (i == -1) {
+ fprintf(stderr, "A display is required first\n");
+ exit(1);
+ }
+
+ fprintf(stderr, "Assigned '%s' to '%s'\n", optarg, displays[i].name);
+ displays[i].mode = optarg;
+ i = -1;
+ break;
+ default:
+ usage(argv[0], 1);
+ }
+ }
+
+ // Trailing args
+ if (optind != argc) {
+ usage(argv[0], 1);
+ }
+}
+
+int main(int argc, char *argv[])
+{
+ parse_args(argc, argv);
+
+ struct otd *otd = otd_start();
+ if (!otd)
+ return 1;
+
+ float colour[3] = {1.0, 0.0, 0.0};
+ int dec = 0;
+
+ struct timespec start, now;
+ clock_gettime(CLOCK_MONOTONIC, &start);
+ struct timespec last = start;
+
+ while (clock_gettime(CLOCK_MONOTONIC, &now) == 0 &&
+ now.tv_sec < start.tv_sec + 10) {
+
+ struct otd_event ev;
+ if (!otd_get_event(otd, &ev))
+ continue;
+
+ struct otd_display *disp = ev.display;
+
+ switch (ev.type) {
+ case OTD_EV_RENDER:
+ rendering_begin(disp);
+
+ // This is all just calculating the colours.
+ // It's not particularly important.
+
+ long ms = (now.tv_sec - last.tv_sec) * 1000 +
+ (now.tv_nsec - last.tv_nsec) / 1000000;
+
+ int inc = (dec + 1) % 3;
+
+ colour[dec] -= ms / 2000.0f;
+ colour[inc] += ms / 2000.0f;
+
+ if (colour[dec] < 0.0f) {
+ colour[dec] = 0.0f;
+ colour[inc] = 1.0f;
+
+ dec = (dec + 1) % 3;
+ }
+
+ last = now;
+
+ glViewport(0, 0, disp->width, disp->height);
+ glClearColor(colour[0], colour[1], colour[2], 1.0f);
+ glClear(GL_COLOR_BUFFER_BIT);
+
+ rendering_end(disp);
+ break;
+ case OTD_EV_DISPLAY_REM:
+ printf("%s removed\n", disp->name);
+ break;
+ case OTD_EV_DISPLAY_ADD:
+ printf("%s added\n", disp->name);
+
+ const char *mode = NULL;
+ for (int i = 0; i < num_displays; ++i) {
+ if (strcmp(disp->name, displays[i].name) == 0) {
+ mode = displays[i].mode;
+ }
+ }
+ if (!mode)
+ mode = "preferred";
+
+ if (!modeset_str(otd, ev.display, mode)) {
+ fprintf(stderr, "Modesetting %s failed\n", disp->name);
+ goto out;
+ }
+ break;
+ default:
+ break;
+ }
+ }
+
+out:
+ otd_finish(otd);
+}
diff --git a/backend/drm/otd.c b/backend/drm/otd.c
new file mode 100644
index 00000000..3d5345c7
--- /dev/null
+++ b/backend/drm/otd.c
@@ -0,0 +1,71 @@
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "otd.h"
+#include "drm.h"
+#include "event.h"
+#include "session.h"
+#include "udev.h"
+
+struct otd *otd_start(void)
+{
+ struct otd *otd = calloc(1, sizeof *otd);
+ if (!otd)
+ return NULL;
+
+ if (!otd_new_session(otd)) {
+ fprintf(stderr, "Could not create session\n");
+ goto error;
+ }
+
+ if (!otd_udev_start(otd)) {
+ fprintf(stderr, "Could not start udev\n");
+ goto error_session;
+ }
+
+ otd_udev_find_gpu(otd);
+ if (otd->fd == -1) {
+ fprintf(stderr, "Could not open GPU\n");
+ goto error_udev;
+ }
+
+ if (!init_renderer(otd)) {
+ fprintf(stderr, "Could not initalise renderer\n");
+ goto error_fd;
+ }
+
+ scan_connectors(otd);
+
+ return otd;
+
+error_fd:
+ release_device(otd, otd->fd);
+error_udev:
+ otd_udev_finish(otd);
+error_session:
+ otd_close_session(otd);
+error:
+ free(otd);
+ return NULL;
+}
+
+void otd_finish(struct otd *otd)
+{
+ if (!otd)
+ return;
+
+ for (size_t i = 0; i < otd->display_len; ++i) {
+ destroy_display_renderer(otd, &otd->displays[i]);
+ }
+
+ destroy_renderer(otd);
+ otd_close_session(otd);
+ otd_udev_finish(otd);
+
+ close(otd->fd);
+ free(otd->events);
+ free(otd->displays);
+ free(otd);
+}
+
diff --git a/backend/drm/otd.h b/backend/drm/otd.h
new file mode 100644
index 00000000..eef0e991
--- /dev/null
+++ b/backend/drm/otd.h
@@ -0,0 +1,44 @@
+#ifndef LIBOTD_H
+#define LIBOTD_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <EGL/egl.h>
+#include <gbm.h>
+#include <libudev.h>
+
+#include "session.h"
+
+struct otd {
+ int fd;
+ bool paused;
+
+ // Priority Queue (Max-heap)
+ size_t event_cap;
+ size_t event_len;
+ struct otd_event *events;
+
+ size_t display_len;
+ struct otd_display *displays;
+
+ uint32_t taken_crtcs;
+
+ struct gbm_device *gbm;
+ struct {
+ EGLDisplay disp;
+ EGLConfig conf;
+ EGLContext context;
+ } egl;
+
+ struct otd_session session;
+
+ struct udev *udev;
+ struct udev_monitor *mon;
+ int udev_fd;
+ char *drm_path;
+};
+
+struct otd *otd_start(void);
+void otd_finish(struct otd *otd);
+
+#endif
diff --git a/backend/drm/session.c b/backend/drm/session.c
new file mode 100644
index 00000000..c845fb27
--- /dev/null
+++ b/backend/drm/session.c
@@ -0,0 +1,224 @@
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <systemd/sd-bus.h>
+#include <systemd/sd-login.h>
+#include <unistd.h>
+#include <sys/sysmacros.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "session.h"
+#include "otd.h"
+
+int take_device(struct otd *restrict otd,
+ const char *restrict path,
+ bool *restrict paused_out)
+{
+ int ret;
+ int fd = -1;
+ sd_bus_message *msg = NULL;
+ sd_bus_error error = SD_BUS_ERROR_NULL;
+ struct otd_session *s = &otd->session;
+
+ struct stat st;
+ if (stat(path, &st) < 0) {
+ fprintf(stderr, "Failed to stat '%s'\n", path);
+ return -1;
+ }
+
+ ret = sd_bus_call_method(s->bus,
+ "org.freedesktop.login1",
+ s->path,
+ "org.freedesktop.login1.Session",
+ "TakeDevice",
+ &error, &msg,
+ "uu", major(st.st_rdev), minor(st.st_rdev));
+ if (ret < 0) {
+ fprintf(stderr, "%s\n", error.message);
+ goto error;
+ }
+
+ int paused = 0;
+ ret = sd_bus_message_read(msg, "hb", &fd, &paused);
+ if (ret < 0) {
+ fprintf(stderr, "%s\n", strerror(-ret));
+ goto error;
+ }
+
+ // The original fd seem to be closed when the message is freed
+ // so we just clone it.
+ fd = fcntl(fd, F_DUPFD_CLOEXEC, 0);
+
+ if (paused_out)
+ *paused_out = paused;
+
+error:
+ sd_bus_error_free(&error);
+ sd_bus_message_unref(msg);
+ return fd;
+}
+
+void release_device(struct otd *otd, int fd)
+{
+ int ret;
+ sd_bus_message *msg = NULL;
+ sd_bus_error error = SD_BUS_ERROR_NULL;
+ struct otd_session *s = &otd->session;
+
+ struct stat st;
+ if (fstat(fd, &st) < 0) {
+ fprintf(stderr, "Could not stat fd %d\n", fd);
+ return;
+ }
+
+ ret = sd_bus_call_method(s->bus,
+ "org.freedesktop.login1",
+ s->path,
+ "org.freedesktop.login1.Session",
+ "ReleaseDevice",
+ &error, &msg,
+ "uu", major(st.st_rdev), minor(st.st_rdev));
+ if (ret < 0) {
+ /* Log something */;
+ }
+
+ sd_bus_error_free(&error);
+ sd_bus_message_unref(msg);
+}
+
+static bool session_activate(struct otd *otd)
+{
+ int ret;
+ sd_bus_message *msg = NULL;
+ sd_bus_error error = SD_BUS_ERROR_NULL;
+ struct otd_session *s = &otd->session;
+
+ ret = sd_bus_call_method(s->bus,
+ "org.freedesktop.login1",
+ s->path,
+ "org.freedesktop.login1.Session",
+ "Activate",
+ &error, &msg,
+ "");
+ if (ret < 0) {
+ fprintf(stderr, "%s\n", error.message);
+ }
+
+ sd_bus_error_free(&error);
+ sd_bus_message_unref(msg);
+ return ret >= 0;
+}
+
+static bool take_control(struct otd *otd)
+{
+ int ret;
+ sd_bus_message *msg = NULL;
+ sd_bus_error error = SD_BUS_ERROR_NULL;
+ struct otd_session *s = &otd->session;
+
+ ret = sd_bus_call_method(s->bus,
+ "org.freedesktop.login1",
+ s->path,
+ "org.freedesktop.login1.Session",
+ "TakeControl",
+ &error, &msg,
+ "b", false);
+ if (ret < 0) {
+ /* Log something */;
+ }
+
+ sd_bus_error_free(&error);
+ sd_bus_message_unref(msg);
+ return ret >= 0;
+}
+
+static void release_control(struct otd *otd)
+{
+ int ret;
+ sd_bus_message *msg = NULL;
+ sd_bus_error error = SD_BUS_ERROR_NULL;
+ struct otd_session *s = &otd->session;
+
+ ret = sd_bus_call_method(s->bus,
+ "org.freedesktop.login1",
+ s->path,
+ "org.freedesktop.login1.Session",
+ "ReleaseControl",
+ &error, &msg,
+ "");
+ if (ret < 0) {
+ /* Log something */;
+ }
+
+ sd_bus_error_free(&error);
+ sd_bus_message_unref(msg);
+}
+
+void otd_close_session(struct otd *otd)
+{
+ release_device(otd, otd->fd);
+ release_control(otd);
+
+ sd_bus_unref(otd->session.bus);
+ free(otd->session.id);
+ free(otd->session.path);
+ free(otd->session.seat);
+}
+
+bool otd_new_session(struct otd *otd)
+{
+ int ret;
+ struct otd_session *s = &otd->session;
+
+ ret = sd_pid_get_session(getpid(), &s->id);
+ if (ret < 0) {
+ fprintf(stderr, "Could not get session\n");
+ goto error;
+ }
+
+ ret = sd_session_get_seat(s->id, &s->seat);
+ if (ret < 0) {
+ fprintf(stderr, "Could not get seat\n");
+ goto error;
+ }
+
+ // This could be done using asprintf, but I don't want to define _GNU_SOURCE
+
+ const char *fmt = "/org/freedesktop/login1/session/%s";
+ int len = snprintf(NULL, 0, fmt, s->id);
+
+ s->path = malloc(len + 1);
+ if (!s->path)
+ goto error;
+
+ sprintf(s->path, fmt, s->id);
+
+ ret = sd_bus_open_system(&s->bus);
+ if (ret < 0) {
+ fprintf(stderr, "Could not open bus\n");
+ goto error;
+ }
+
+ if (!session_activate(otd)) {
+ fprintf(stderr, "Could not activate session\n");
+ goto error_bus;
+ }
+
+ if (!take_control(otd)) {
+ fprintf(stderr, "Could not take control of session\n");
+ goto error_bus;
+ }
+
+ return true;
+
+error_bus:
+ sd_bus_unref(s->bus);
+
+error:
+ free(s->path);
+ free(s->id);
+ free(s->seat);
+ return false;
+}
diff --git a/backend/drm/session.h b/backend/drm/session.h
new file mode 100644
index 00000000..c21900e9
--- /dev/null
+++ b/backend/drm/session.h
@@ -0,0 +1,25 @@
+#ifndef SESSION_H
+#define SESSION_H
+
+#include <systemd/sd-bus.h>
+#include <stdbool.h>
+
+struct otd_session {
+ char *id;
+ char *path;
+ char *seat;
+
+ sd_bus *bus;
+};
+
+struct otd;
+bool otd_new_session(struct otd *otd);
+void otd_close_session(struct otd *otd);
+
+int take_device(struct otd *restrict otd,
+ const char *restrict path,
+ bool *restrict paused_out);
+
+void release_device(struct otd *otd, int fd);
+
+#endif
diff --git a/backend/drm/udev.c b/backend/drm/udev.c
new file mode 100644
index 00000000..1efa26c2
--- /dev/null
+++ b/backend/drm/udev.c
@@ -0,0 +1,158 @@
+#include <libudev.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <xf86drm.h>
+#include <xf86drmMode.h>
+
+#include "otd.h"
+#include "udev.h"
+#include "session.h"
+#include "drm.h"
+
+static bool device_is_kms(struct otd *otd, struct udev_device *dev)
+{
+ const char *path = udev_device_get_devnode(dev);
+ int fd;
+
+ if (!path)
+ return false;
+
+ fd = take_device(otd, path, &otd->paused);
+ if (fd < 0)
+ return false;
+
+ drmModeRes *res = drmModeGetResources(fd);
+ if (!res)
+ goto out_fd;
+
+ if (res->count_crtcs <= 0 || res->count_connectors <= 0 ||
+ res->count_encoders <= 0)
+ goto out_res;
+
+ if (otd->fd >= 0) {
+ release_device(otd, otd->fd);
+ free(otd->drm_path);
+ }
+
+ otd->fd = fd;
+ otd->drm_path = strdup(path);
+
+ drmModeFreeResources(res);
+ return true;
+
+out_res:
+ drmModeFreeResources(res);
+out_fd:
+ release_device(otd, fd);
+ return false;
+}
+
+void otd_udev_find_gpu(struct otd *otd)
+{
+ struct udev *udev = otd->udev;
+ otd->fd = -1;
+
+ struct udev_enumerate *en = udev_enumerate_new(udev);
+ if (!en)
+ return;
+
+ udev_enumerate_add_match_subsystem(en, "drm");
+ udev_enumerate_add_match_sysname(en, "card[0-9]*");
+
+ udev_enumerate_scan_devices(en);
+ struct udev_list_entry *entry;
+ udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(en)) {
+ bool is_boot_vga = false;
+
+ const char *path = udev_list_entry_get_name(entry);
+ struct udev_device *dev = udev_device_new_from_syspath(udev, path);
+ if (!dev)
+ continue;
+
+ const char *seat = udev_device_get_property_value(dev, "ID_SEAT");
+ if (!seat)
+ seat = "seat0";
+ if (strcmp(otd->session.seat, seat) != 0) {
+ udev_device_unref(dev);
+ continue;
+ }
+
+ struct udev_device *pci =
+ udev_device_get_parent_with_subsystem_devtype(dev,
+ "pci", NULL);
+
+ if (pci) {
+ const char *id = udev_device_get_sysattr_value(pci, "boot_vga");
+ if (id && strcmp(id, "1") == 0)
+ is_boot_vga = true;
+ udev_device_unref(pci);
+ }
+
+ if (!is_boot_vga && otd->fd >= 0) {
+ udev_device_unref(dev);
+ continue;
+ }
+
+ if (!device_is_kms(otd, dev)) {
+ udev_device_unref(dev);
+ continue;
+ }
+
+ if (is_boot_vga) {
+ break;
+ }
+ }
+
+ udev_enumerate_unref(en);
+}
+
+bool otd_udev_start(struct otd *otd)
+{
+ otd->udev = udev_new();
+ if (!otd->udev)
+ return false;
+
+ otd->mon = udev_monitor_new_from_netlink(otd->udev, "udev");
+ if (!otd->mon) {
+ udev_unref(otd->udev);
+ return false;
+ }
+
+ udev_monitor_filter_add_match_subsystem_devtype(otd->mon, "drm", NULL);
+ udev_monitor_enable_receiving(otd->mon);
+
+ otd->udev_fd = udev_monitor_get_fd(otd->mon);
+
+ return true;
+}
+
+void otd_udev_finish(struct otd *otd)
+{
+ if (!otd)
+ return;
+
+ udev_monitor_unref(otd->mon);
+ udev_unref(otd->udev);
+}
+
+void otd_udev_event(struct otd *otd)
+{
+ struct udev_device *dev = udev_monitor_receive_device(otd->mon);
+ if (!dev)
+ return;
+
+ const char *path = udev_device_get_devnode(dev);
+ if (!path || strcmp(path, otd->drm_path) != 0)
+ goto out;
+
+ const char *action = udev_device_get_action(dev);
+ if (!action || strcmp(action, "change") != 0)
+ goto out;
+
+ scan_connectors(otd);
+
+out:
+ udev_device_unref(dev);
+}
diff --git a/backend/drm/udev.h b/backend/drm/udev.h
new file mode 100644
index 00000000..9bd4c0d0
--- /dev/null
+++ b/backend/drm/udev.h
@@ -0,0 +1,9 @@
+#ifndef UDEV_H
+#define UDEV_H
+
+bool otd_udev_start(struct otd *otd);
+void otd_udev_finish(struct otd *otd);
+void otd_udev_find_gpu(struct otd *otd);
+void otd_udev_event(struct otd *otd);
+
+#endif