* @value: value of the event
*
* This function should be used by drivers implementing various input
- * devices. See also input_inject_event().
+ * devices to report input events. See also input_inject_event().
+ *
+ * NOTE: input_event() may be safely used right after input device was
+ * allocated with input_allocate_device(), even before it is registered
+ * with input_register_device(), but the event will not reach any of the
+ * input handlers. Such early invocation of input_event() may be used
+ * to 'seed' initial state of a switch or initial position of absolute
+ * axis, etc.
*/
-
void input_event(struct input_dev *dev,
unsigned int type, unsigned int code, int value)
{
}
EXPORT_SYMBOL(input_unregister_handler);
+/**
+ * input_handler_for_each_handle - handle iterator
+ * @handler: input handler to iterate
+ * @data: data for the callback
+ * @fn: function to be called for each handle
+ *
+ * Iterate over @bus's list of devices, and call @fn for each, passing
+ * it @data and stop when @fn returns a non-zero value. The function is
+ * using RCU to traverse the list and therefore may be usind in atonic
+ * contexts. The @fn callback is invoked from RCU critical section and
+ * thus must not sleep.
+ */
+int input_handler_for_each_handle(struct input_handler *handler, void *data,
+ int (*fn)(struct input_handle *, void *))
+{
+ struct input_handle *handle;
+ int retval = 0;
+
+ rcu_read_lock();
+
+ list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
+ retval = fn(handle, data);
+ if (retval)
+ break;
+ }
+
+ rcu_read_unlock();
+
+ return retval;
+}
+EXPORT_SYMBOL(input_handler_for_each_handle);
+
/**
* input_register_handle - register a new input handle
* @handle: handle to register
* we can't be racing with input_unregister_handle()
* and so separate lock is not needed here.
*/
- list_add_tail(&handle->h_node, &handler->h_list);
+ list_add_tail_rcu(&handle->h_node, &handler->h_list);
if (handler->start)
handler->start(handle);
{
struct input_dev *dev = handle->dev;
- list_del_init(&handle->h_node);
+ list_del_rcu(&handle->h_node);
/*
* Take dev->mutex to prevent race with input_release_device().
mutex_lock(&dev->mutex);
list_del_rcu(&handle->d_node);
mutex_unlock(&dev->mutex);
+
synchronize_rcu();
}
EXPORT_SYMBOL(input_unregister_handle);