xf86drm: add a non-sysfs version of drmGetDeviceNameFromFd2
Implement a generic drmGetDeviceNameFromFd2() to use on non-linux
systems without sysfs.
v2: remove min < base test as requested by Emil
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Jonathan Gray <jsg@jsg.id.au>
diff --git a/xf86drm.c b/xf86drm.c
index f6850aa..f684c01 100644
--- a/xf86drm.c
+++ b/xf86drm.c
@@ -3627,7 +3627,47 @@
fclose(f);
return device_name;
#else
-#warning "Missing implementation of drmGetDeviceNameFromFd2"
- return NULL;
+ struct stat sbuf;
+ char node[PATH_MAX + 1];
+ const char *dev_name;
+ int node_type;
+ int maj, min, n, base;
+
+ if (fstat(fd, &sbuf))
+ return NULL;
+
+ maj = major(sbuf.st_rdev);
+ min = minor(sbuf.st_rdev);
+
+ if (maj != DRM_MAJOR || !S_ISCHR(sbuf.st_mode))
+ return NULL;
+
+ node_type = drmGetMinorType(min);
+ if (node_type == -1)
+ return NULL;
+
+ switch (node_type) {
+ case DRM_NODE_PRIMARY:
+ dev_name = DRM_DEV_NAME;
+ break;
+ case DRM_NODE_CONTROL:
+ dev_name = DRM_CONTROL_DEV_NAME;
+ break;
+ case DRM_NODE_RENDER:
+ dev_name = DRM_RENDER_DEV_NAME;
+ break;
+ default:
+ return NULL;
+ };
+
+ base = drmGetMinorBase(node_type);
+ if (base < 0)
+ return NULL;
+
+ n = snprintf(node, PATH_MAX, dev_name, DRM_DIR_NAME, min - base);
+ if (n == -1 || n >= PATH_MAX)
+ return NULL;
+
+ return strdup(node);
#endif
}
