[PATCH v3 5/6] libweston: fbdev: Attempt to detect the first framebuffer device in the seat. instead of defaulting to /dev/fb0

[nerdopolis]

This adds a function to detect the first framebuffer device in the
current seat. Instead of hardcoding /dev/fb0, use udev to find the
first framebuffer device in the seat.
---
 libweston/compositor-fbdev.c | 45 +++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 42 insertions(+), 3 deletions(-)

diff --git a/libweston/compositor-fbdev.c b/libweston/compositor-fbdev.c
index 18af7082..cad4b202 100644
--- a/libweston/compositor-fbdev.c
+++ b/libweston/compositor-fbdev.c
@@ -711,6 +711,42 @@ fbdev_restore(struct weston_compositor *compositor)
        weston_launcher_restore(compositor->launcher);
 }
 
+static char *
+find_framebuffer_device(struct fbdev_backend *b, const char *seat)
+{
+       struct udev_enumerate *e;
+       struct udev_list_entry *entry;
+       const char *path, *device_seat;
+       char *fb_device;
+       struct udev_device *device;
+
+       e = udev_enumerate_new(b->udev);
+       udev_enumerate_add_match_subsystem(e, "graphics");
+       udev_enumerate_add_match_sysname(e, "fb[0-9]*");
+
+       udev_enumerate_scan_devices(e);
+       fb_device = NULL;
+       udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(e)) {
+
+               path = udev_list_entry_get_name(entry);
+               device = udev_device_new_from_syspath(b->udev, path);
+               if (!device)
+                       continue;
+               device_seat = udev_device_get_property_value(device, "ID_SEAT");
+               if (!device_seat)
+                       device_seat = default_seat;
+               if (!strcmp(device_seat, seat)) {
+                       fb_device = udev_device_get_devnode(device);
+                       udev_enumerate_unref(e);
+                       break;
+               }
+               udev_device_unref(device);
+       }
+
+       udev_enumerate_unref(e);
+       return fb_device;
+}
+
 static struct fbdev_backend *
 fbdev_backend_create(struct weston_compositor *compositor,
                      struct weston_fbdev_backend_config *param)
@@ -743,6 +779,11 @@ fbdev_backend_create(struct weston_compositor *compositor,
                goto out_compositor;
        }
 
+       if (!param->device)
+               find_framebuffer_device(backend, seat_id);
+       if (!param->device)
+               param->device=strdup("/dev/fb0");
+
        /* Set up the TTY. */
        backend->session_listener.notify = session_notify;
        wl_signal_add(&compositor->session_signal,
@@ -789,10 +830,8 @@ out_compositor:
 static void
 config_init_to_defaults(struct weston_fbdev_backend_config *config)
 {
-       /* TODO: Ideally, available frame buffers should be enumerated using
-        * udev, rather than passing a device node in as a parameter. */
        config->tty = 0; /* default to current tty */
-       config->device = "/dev/fb0"; /* default frame buffer */
+       config->device = NULL;
        config->seat_id = NULL;
 }
 
-- 
2.14.1

_______________________________________________
wayland-devel mailing list
wayland-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/wayland-devel