+
+static struct device * next_device(struct klist_iter * i)
+{
+ struct klist_node * n = klist_next(i);
+ return n ? container_of(n, struct device, knode_driver) : NULL;
+}
+
+/**
+ * driver_for_each_device - Iterator for devices bound to a driver.
+ * @drv: Driver we're iterating.
+ * @start: Device to begin with
+ * @data: Data to pass to the callback.
+ * @fn: Function to call for each device.
+ *
+ * Iterate over the @drv's list of devices calling @fn for each one.
+ */
+
+int driver_for_each_device(struct device_driver * drv, struct device * start,
+ void * data, int (*fn)(struct device *, void *))
+{
+ struct klist_iter i;
+ struct device * dev;
+ int error = 0;
+
+ if (!drv)
+ return -EINVAL;
+
+ klist_iter_init_node(&drv->klist_devices, &i,
+ start ? &start->knode_driver : NULL);
+ while ((dev = next_device(&i)) && !error)
+ error = fn(dev, data);
+ klist_iter_exit(&i);
+ return error;
+}
+
+EXPORT_SYMBOL_GPL(driver_for_each_device);
+
+
+/**
+ * driver_find_device - device iterator for locating a particular device.
+ * @drv: The device's driver
+ * @start: Device to begin with
+ * @data: Data to pass to match function
+ * @match: Callback function to check device
+ *
+ * This is similar to the driver_for_each_device() function above, but
+ * it returns a reference to a device that is 'found' for later use, as
+ * determined by the @match callback.
+ *
+ * The callback should return 0 if the device doesn't match and non-zero
+ * if it does. If the callback returns non-zero, this function will
+ * return to the caller and not iterate over any more devices.
+ */
+struct device * driver_find_device(struct device_driver *drv,
+ struct device * start, void * data,
+ int (*match)(struct device *, void *))
+{
+ struct klist_iter i;
+ struct device *dev;
+
+ if (!drv)
+ return NULL;
+
+ klist_iter_init_node(&drv->klist_devices, &i,
+ (start ? &start->knode_driver : NULL));
+ while ((dev = next_device(&i)))
+ if (match(dev, data) && get_device(dev))
+ break;
+ klist_iter_exit(&i);
+ return dev;
+}
+EXPORT_SYMBOL_GPL(driver_find_device);
+