Implement drmGetCap() to query device/driver capabilities

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

3 files changed, 22 insertions, 0 deletions

diff --git a/include/drm/drm.h b/include/drm/drm.h
index c968dc81f..416673af0 100644
--- a/include/drm/drm.h
+++ b/include/drm/drm.h
@@ -612,6 +612,12 @@ struct drm_gem_open {
 	__u64 size;
 };
 
+/** DRM_IOCTL_GET_CAP ioctl argument type */
+struct drm_get_cap {
+	__u64 capability;
+	__u64 value;
+};
+
 #include "drm_mode.h"
 
 #define DRM_IOCTL_BASE			'd'
@@ -632,6 +638,7 @@ struct drm_gem_open {
 #define DRM_IOCTL_GEM_CLOSE		DRM_IOW (0x09, struct drm_gem_close)
 #define DRM_IOCTL_GEM_FLINK		DRM_IOWR(0x0a, struct drm_gem_flink)
 #define DRM_IOCTL_GEM_OPEN		DRM_IOWR(0x0b, struct drm_gem_open)
+#define DRM_IOCTL_GET_CAP		DRM_IOWR(0x0c, struct drm_get_cap)
 
 #define DRM_IOCTL_SET_UNIQUE		DRM_IOW( 0x10, struct drm_unique)
 #define DRM_IOCTL_AUTH_MAGIC		DRM_IOW( 0x11, struct drm_auth)
@@ -747,6 +754,8 @@ struct drm_event_vblank {
 	__u32 reserved;
 };
 
+#define DRM_CAP_DUMB_BUFFER 0x1
+
 /* typedef area */
 typedef struct drm_clip_rect drm_clip_rect_t;
 typedef struct drm_drawable_info drm_drawable_info_t;
diff --git a/xf86drm.c b/xf86drm.c
index 799fcddf4..bc7a97fe4 100644
--- a/xf86drm.c
+++ b/xf86drm.c
@@ -810,6 +810,18 @@ drmVersionPtr drmGetLibVersion(int fd)
     return (drmVersionPtr)version;
 }
 
+int drmGetCap(int fd, uint64_t capability, uint64_t *value)
+{
+	struct drm_get_cap cap = { capability, 0 };
+	int ret;
+
+	ret = drmIoctl(fd, DRM_IOCTL_GET_CAP, &cap);
+	if (ret)
+		return ret;
+
+	*value = cap.value;
+	return cap.value;
+}
 
 /**
  * Free the bus ID information.
diff --git a/xf86drm.h b/xf86drm.h
index 9b89f5625..bf0d5df88 100644
--- a/xf86drm.h
+++ b/xf86drm.h
@@ -542,6 +542,7 @@ extern int drmOpenControl(int minor);
 extern int           drmClose(int fd);
 extern drmVersionPtr drmGetVersion(int fd);
 extern drmVersionPtr drmGetLibVersion(int fd);
+extern int           drmGetCap(int fd, uint64_t capability, uint64_t *value);
 extern void          drmFreeVersion(drmVersionPtr);
 extern int           drmGetMagic(int fd, drm_magic_t * magic);
 extern char          *drmGetBusid(int fd);