[PATCH 2/2] libdrm: add drmGetNodeType() helper

[Emil Velikov]

The add a simple helper which returns the node type of the opened fd.
Likely to be used in conjunction with the previous two helpers.

Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: David Herrmann <dh.herrmann at googlemail.com>
Signed-off-by: Emil Velikov <emil.l.velikov at gmail.com>
---
 xf86drm.c | 43 +++++++++++++++++++++++++++++++++++++++----
 xf86drm.h |  7 +++++++
 2 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/xf86drm.c b/xf86drm.c
index 6af7ac0..a70c0dd 100644
--- a/xf86drm.c
+++ b/xf86drm.c
@@ -85,10 +85,6 @@
 
 #define DRM_MSG_VERBOSITY 3
 
-#define DRM_NODE_CONTROL 0
-#define DRM_NODE_PRIMARY 1
-#define DRM_NODE_RENDER 2
-
 static drmServerInfoPtr drm_server_info;
 
 void drmSetServerInfo(drmServerInfoPtr info)
@@ -2607,6 +2603,45 @@ int drmPrimeFDToHandle(int fd, int prime_fd, uint32_t *handle)
 	return 0;
 }
 
+int drmGetNodeType(int fd, drmNodeType *type)
+{
+	struct stat sbuf;
+	char name[64];
+	dev_t d;
+	int i;
+
+	if (!fstat(fd, &sbuf))
+		return -errno;
+
+	d = sbuf.st_rdev;
+
+	for (i = 0; i < DRM_MAX_MINOR; i++) {
+		snprintf(name, sizeof(name), DRM_DEV_NAME, DRM_DIR_NAME, i);
+		if (stat(name, &sbuf) == 0 && sbuf.st_rdev == d) {
+			*type = DRM_NODE_PRIMARY;
+			return 0;
+		}
+	}
+
+	for (i = 64; i < (64 + DRM_MAX_MINOR); i++) {
+		snprintf(name, sizeof(name), DRM_CONTROL_DEV_NAME, DRM_DIR_NAME, i);
+		if (stat(name, &sbuf) == 0 && sbuf.st_rdev == d) {
+			*type = DRM_NODE_CONTROL;
+			return 0;
+		}
+	}
+
+	for (i = 128; i < (128 + DRM_MAX_MINOR); i++) {
+		snprintf(name, sizeof(name), DRM_RENDER_DEV_NAME, DRM_DIR_NAME, i);
+		if (stat(name, &sbuf) == 0 && sbuf.st_rdev == d) {
+			*type = DRM_NODE_RENDER;
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
 char *drmGetDeviceNameFromRenderFD(int fd)
 {
 
diff --git a/xf86drm.h b/xf86drm.h
index bca5887..7d67df9 100644
--- a/xf86drm.h
+++ b/xf86drm.h
@@ -740,6 +740,13 @@ extern char *drmGetDeviceNameFromFd(int fd);
 extern int drmPrimeHandleToFD(int fd, uint32_t handle, uint32_t flags, int *prime_fd);
 extern int drmPrimeFDToHandle(int fd, int prime_fd, uint32_t *handle);
 
+typedef enum _drmNodeType {
+    DRM_NODE_CONTROL = 0,
+    DRM_NODE_PRIMARY = 1,
+    DRM_NODE_RENDER  = 2
+} drmNodeType, *drmNodeTypePtr;
+
+extern int drmGetNodeType(int fd, drmNodeType *type);
 extern char *drmGetRenderNameFromDeviceFD(int fd);
 extern char *drmGetDeviceNameFromRenderFD(int fd);
 
-- 
2.2.2