+ * sysfs_get_classdev_device: returns the sysfs_device corresponding to
+ * sysfs_class_device, if present
+ * @clsdev: class device whose sysfs_device is required
+ * Returns sysfs_device on success, NULL on error or if device is not
+ * implemented
+ */
+struct sysfs_device *sysfs_get_classdev_device
+ (struct sysfs_class_device *clsdev)
+{
+ struct sysfs_link *devlink = NULL;
+ char devpath[SYSFS_PATH_MAX];
+
+ if (clsdev == NULL) {
+ errno = EINVAL;
+ return NULL;
+ }
+ safestrcpy(devpath, clsdev->path);
+ safestrcat(devpath, "/device");
+ if ((sysfs_path_is_link(devpath)) != 0) {
+ if (clsdev->sysdevice != NULL) {
+ sysfs_close_device(clsdev->sysdevice);
+ clsdev->sysdevice = NULL;
+ }
+ return NULL;
+ }
+
+ if (clsdev->directory == NULL) {
+ clsdev->directory = sysfs_open_directory(clsdev->path);
+ if (clsdev->directory == NULL)
+ return NULL;
+ }
+ devlink = sysfs_get_directory_link(clsdev->directory, "device");
+ if (devlink == NULL) {
+ if (clsdev->sysdevice != NULL) {
+ dprintf("Device link no longer exists\n");
+ sysfs_close_device(clsdev->sysdevice);
+ clsdev->sysdevice = NULL;
+ }
+ return NULL;
+ }
+
+ if (clsdev->sysdevice != NULL) {
+ if (!strncmp(devlink->target, clsdev->sysdevice->path,
+ SYSFS_PATH_MAX))
+ /* sysdevice hasn't changed */
+ return (clsdev->sysdevice);
+ else
+ /* come here only if the device link for has changed */
+ sysfs_close_device(clsdev->sysdevice);
+ }
+
+ clsdev->sysdevice = sysfs_open_device_path(devlink->target);
+ if (clsdev->sysdevice == NULL)
+ return NULL;
+
+ return (clsdev->sysdevice);
+}
+
+/**
+ * sysfs_get_classdev_driver: returns the sysfs_driver corresponding to
+ * sysfs_class_device, if present
+ * @clsdev: class device whose sysfs_device is required
+ * Returns sysfs_driver on success, NULL on error or if driver is not
+ * implemented
+ */
+struct sysfs_driver *sysfs_get_classdev_driver
+ (struct sysfs_class_device *clsdev)
+{
+ struct sysfs_link *drvlink = NULL;
+ char drvpath[SYSFS_PATH_MAX];
+
+ if (clsdev == NULL) {
+ errno = EINVAL;
+ return NULL;
+ }
+ safestrcpy(drvpath, clsdev->path);
+ safestrcat(drvpath, "/driver");
+ if ((sysfs_path_is_link(drvpath)) != 0) {
+ if (clsdev->driver != NULL) {
+ sysfs_close_driver(clsdev->driver);
+ clsdev->driver = NULL;
+ }
+ return NULL;
+ }
+
+ if (clsdev->directory == NULL) {
+ clsdev->directory = sysfs_open_directory(clsdev->path);
+ if (clsdev->directory == NULL)
+ return NULL;
+ }
+ drvlink = sysfs_get_directory_link(clsdev->directory, "driver");
+ if (drvlink == NULL) {
+ if (clsdev->driver != NULL) {
+ dprintf("Driver link no longer exists\n");
+ sysfs_close_driver(clsdev->driver);
+ clsdev->driver = NULL;
+ }
+ return NULL;
+ }
+ if (clsdev->driver != NULL) {
+ if (!strncmp(drvlink->target, clsdev->driver->path,
+ SYSFS_PATH_MAX))
+ /* driver hasn't changed */
+ return (clsdev->driver);
+ else
+ /* come here only if the device link for has changed */
+ sysfs_close_driver(clsdev->driver);
+ }
+
+ clsdev->driver = sysfs_open_driver_path(drvlink->target);
+ if (clsdev->driver == NULL)
+ return NULL;
+
+ return (clsdev->driver);
+}
+
+/**
+ * get_blockdev_parent: Get the parent class device for a "block" subsystem
+ * device if present
+ * @clsdev: block subsystem class device whose parent needs to be found
+ * Returns 0 on success and 1 on error