main: collect one DRM device per seat

We need a single graphics card on a seat to run kmscon. Therefore, wait
for the first DRM device that appears and make it the current graphics
device for the seat. We do not support multiple graphics cards per seat
but this may be added in the future.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>

diff --git a/src/main.c b/src/main.c
index 77ab273..33421d8 100644 (file)
--- a/src/main.c
+++ b/src/main.c
@@ -58,6 +58,18 @@ struct kmscon_seat {
 
        struct uterm_monitor_seat *useat;
        char *sname;
+
+       /*
+        * Session Data
+        * We currently allow only a single session on each seat. That is, only
+        * one kmscon instance can run in a single process on each seat. If you
+        * want multiple instances, then start kmscon twice.
+        * We also allow only a single graphics card per seat.
+        * TODO: support multiple sessions per seat in a single kmscon process
+        */
+
+       struct uterm_monitor_dev *vdev;
+       struct uterm_video *video;
 };
 
 static void sig_generic(struct ev_eloop *eloop, struct signalfd_siginfo *info,
@@ -132,6 +144,38 @@ static void seat_free(struct kmscon_seat *seat)
        free(seat);
 }
 
+static void seat_add_video(struct kmscon_seat *seat,
+                          struct uterm_monitor_dev *dev,
+                          const char *node)
+{
+       int ret;
+
+       if (seat->video)
+               return;
+
+       ret = uterm_video_new(&seat->video, seat->app->eloop, UTERM_VIDEO_DRM,
+                             node);
+       if (ret)
+               return;
+
+       seat->vdev = dev;
+
+       log_debug("new graphics device on seat %s", seat->sname);
+}
+
+static void seat_rm_video(struct kmscon_seat *seat,
+                         struct uterm_monitor_dev *dev)
+{
+       if (!seat->video || seat->vdev != dev)
+               return;
+
+       log_debug("free graphics device on seat %s", seat->sname);
+
+       seat->vdev = NULL;
+       uterm_video_unref(seat->video);
+       seat->video = NULL;
+}
+
 static void monitor_event(struct uterm_monitor *mon,
                          struct uterm_monitor_event *ev,
                          void *data)
@@ -147,8 +191,16 @@ static void monitor_event(struct uterm_monitor *mon,
                        seat_free(ev->seat_data);
                break;
        case UTERM_MONITOR_NEW_DEV:
+               if (!ev->seat_data)
+                       break;
+               if (ev->dev_type == UTERM_MONITOR_DRM)
+                       seat_add_video(ev->seat_data, ev->dev, ev->dev_node);
                break;
        case UTERM_MONITOR_FREE_DEV:
+               if (!ev->seat_data)
+                       break;
+               if (ev->dev_type == UTERM_MONITOR_DRM)
+                       seat_rm_video(ev->seat_data, ev->dev);
                break;
        case UTERM_MONITOR_HOTPLUG_DEV:
                break;