drm: add atomic properties

Once a driver is using atomic helpers for modeset, the next step is to
switch over to atomic properties.  To do this, make sure that any
modeset objects have their ->atomic_{get,set}_property() vfuncs suitably
populated if they have custom properties (you did already remember to
plug in atomic-helper func for the legacy ->set_property() vfuncs,
right?), and then set DRIVER_ATOMIC bit in driver_features flag.

A new cap is introduced, DRM_CLIENT_CAP_ATOMIC, for the purposes of
shielding legacy userspace from atomic properties.  Mostly for the
benefit of legacy DDX drivers that do silly things like getting/setting
each property at startup (since some of the new atomic properties will
be able to trigger modeset).

Signed-off-by: Rob Clark <robdclark@gmail.com>
[danvet: Squash in fixup patch to check for DRM_MODE_PROP_ATOMIC
instaed of the CAP define when filtering properties. Reported by
Tvrtko Uruslin, acked by Rob.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

2 files changed, 14 insertions, 0 deletions

diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
index b0b855613641..f7b2baf7ecb2 100644
--- a/include/uapi/drm/drm.h
+++ b/include/uapi/drm/drm.h
@@ -654,6 +654,13 @@ struct drm_get_cap {
  */
 #define DRM_CLIENT_CAP_UNIVERSAL_PLANES  2
 
+/**
+ * DRM_CLIENT_CAP_ATOMIC
+ *
+ * If set to 1, the DRM core will expose atomic properties to userspace
+ */
+#define DRM_CLIENT_CAP_ATOMIC   3
+
 /** DRM_IOCTL_SET_CLIENT_CAP ioctl argument type */
 struct drm_set_client_cap {
         __u64 capability;
diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
index aae71cb32123..b8f9c0f2e7fe 100644
--- a/include/uapi/drm/drm_mode.h
+++ b/include/uapi/drm/drm_mode.h
@@ -272,6 +272,13 @@ struct drm_mode_get_connector {
 #define DRM_MODE_PROP_OBJECT            DRM_MODE_PROP_TYPE(1)
 #define DRM_MODE_PROP_SIGNED_RANGE      DRM_MODE_PROP_TYPE(2)
 
+/* the PROP_ATOMIC flag is used to hide properties from userspace that
+ * is not aware of atomic properties.  This is mostly to work around
+ * older userspace (DDX drivers) that read/write each prop they find,
+ * witout being aware that this could be triggering a lengthy modeset.
+ */
+#define DRM_MODE_PROP_ATOMIC        0x80000000
+
 struct drm_mode_property_enum {
         __u64 value;
         char name[DRM_PROP_NAME_LEN];