Inital commit of libotd.

1 files changed, 158 insertions, 0 deletions

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);
+}