static void __input_release_device(struct input_handle *handle)
{
struct input_dev *dev = handle->dev;
+ struct input_handle *grabber;
- if (dev->grab == handle) {
+ grabber = rcu_dereference_protected(dev->grab,
+ lockdep_is_held(&dev->mutex));
+ if (grabber == handle) {
rcu_assign_pointer(dev->grab, NULL);
/* Make sure input_pass_event() notices that grab is gone */
synchronize_rcu();
/**
* input_allocate_device - allocate memory for new input device
*
- * Returns prepared struct input_dev or NULL.
+ * Returns prepared struct input_dev or %NULL.
*
* NOTE: Use input_free_device() to free devices that have not been
* registered; input_unregister_device() should be used for already
}
EXPORT_SYMBOL(input_allocate_device);
+struct input_devres {
+ struct input_dev *input;
+};
+
+static int devm_input_device_match(struct device *dev, void *res, void *data)
+{
+ struct input_devres *devres = res;
+
+ return devres->input == data;
+}
+
+static void devm_input_device_release(struct device *dev, void *res)
+{
+ struct input_devres *devres = res;
+ struct input_dev *input = devres->input;
+
+ dev_dbg(dev, "%s: dropping reference to %s\n",
+ __func__, dev_name(&input->dev));
+ input_put_device(input);
+}
+
+/**
+ * devm_input_allocate_device - allocate managed input device
+ * @dev: device owning the input device being created
+ *
+ * Returns prepared struct input_dev or %NULL.
+ *
+ * Managed input devices do not need to be explicitly unregistered or
+ * freed as it will be done automatically when owner device unbinds from
+ * its driver (or binding fails). Once managed input device is allocated,
+ * it is ready to be set up and registered in the same fashion as regular
+ * input device. There are no special devm_input_device_[un]register()
+ * variants, regular ones work with both managed and unmanaged devices,
+ * should you need them. In most cases however, managed input device need
+ * not be explicitly unregistered or freed.
+ *
+ * NOTE: the owner device is set up as parent of input device and users
+ * should not override it.
+ */
+struct input_dev *devm_input_allocate_device(struct device *dev)
+{
+ struct input_dev *input;
+ struct input_devres *devres;
+
+ devres = devres_alloc(devm_input_device_release,
+ sizeof(struct input_devres), GFP_KERNEL);
+ if (!devres)
+ return NULL;
+
+ input = input_allocate_device();
+ if (!input) {
+ devres_free(devres);
+ return NULL;
+ }
+
+ input->dev.parent = dev;
+ input->devres_managed = true;
+
+ devres->input = input;
+ devres_add(dev, devres);
+
+ return input;
+}
+EXPORT_SYMBOL(devm_input_allocate_device);
+
/**
* input_free_device - free memory occupied by input_dev structure
* @dev: input device to free
*/
void input_free_device(struct input_dev *dev)
{
- if (dev)
+ if (dev) {
+ if (dev->devres_managed)
+ WARN_ON(devres_destroy(dev->dev.parent,
+ devm_input_device_release,
+ devm_input_device_match,
+ dev));
input_put_device(dev);
+ }
}
EXPORT_SYMBOL(input_free_device);
INPUT_CLEANSE_BITMASK(dev, SW, sw);
}
+static void __input_unregister_device(struct input_dev *dev)
+{
+ struct input_handle *handle, *next;
+
+ input_disconnect_device(dev);
+
+ mutex_lock(&input_mutex);
+
+ list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
+ handle->handler->disconnect(handle);
+ WARN_ON(!list_empty(&dev->h_list));
+
+ del_timer_sync(&dev->timer);
+ list_del_init(&dev->node);
+
+ input_wakeup_procfs_readers();
+
+ mutex_unlock(&input_mutex);
+
+ device_del(&dev->dev);
+}
+
+static void devm_input_device_unregister(struct device *dev, void *res)
+{
+ struct input_devres *devres = res;
+ struct input_dev *input = devres->input;
+
+ dev_dbg(dev, "%s: unregistering device %s\n",
+ __func__, dev_name(&input->dev));
+ __input_unregister_device(input);
+}
+
/**
* input_register_device - register device with input core
* @dev: device to be registered
* Once device has been successfully registered it can be unregistered
* with input_unregister_device(); input_free_device() should not be
* called in this case.
+ *
+ * Note that this function is also used to register managed input devices
+ * (ones allocated with devm_input_allocate_device()). Such managed input
+ * devices need not be explicitly unregistered or freed, their tear down
+ * is controlled by the devres infrastructure. It is also worth noting
+ * that tear down of managed input devices is internally a 2-step process:
+ * registered managed input device is first unregistered, but stays in
+ * memory and can still handle input_event() calls (although events will
+ * not be delivered anywhere). The freeing of managed input device will
+ * happen later, when devres stack is unwound to the point where device
+ * allocation was made.
*/
int input_register_device(struct input_dev *dev)
{
static atomic_t input_no = ATOMIC_INIT(0);
+ struct input_devres *devres = NULL;
struct input_handler *handler;
unsigned int packet_size;
const char *path;
int error;
+ if (dev->devres_managed) {
+ devres = devres_alloc(devm_input_device_unregister,
+ sizeof(struct input_devres), GFP_KERNEL);
+ if (!devres)
+ return -ENOMEM;
+
+ devres->input = dev;
+ }
+
/* Every input device generates EV_SYN/SYN_REPORT events. */
__set_bit(EV_SYN, dev->evbit);
dev->max_vals = max(dev->hint_events_per_packet, packet_size) + 2;
dev->vals = kcalloc(dev->max_vals, sizeof(*dev->vals), GFP_KERNEL);
- if (!dev->vals)
- return -ENOMEM;
+ if (!dev->vals) {
+ error = -ENOMEM;
+ goto err_devres_free;
+ }
/*
* If delay and period are pre-set by the driver, then autorepeating
error = device_add(&dev->dev);
if (error)
- return error;
+ goto err_free_vals;
path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
pr_info("%s as %s\n",
kfree(path);
error = mutex_lock_interruptible(&input_mutex);
- if (error) {
- device_del(&dev->dev);
- return error;
- }
+ if (error)
+ goto err_device_del;
list_add_tail(&dev->node, &input_dev_list);
mutex_unlock(&input_mutex);
+ if (dev->devres_managed) {
+ dev_dbg(dev->dev.parent, "%s: registering %s with devres.\n",
+ __func__, dev_name(&dev->dev));
+ devres_add(dev->dev.parent, devres);
+ }
return 0;
+
+err_device_del:
+ device_del(&dev->dev);
+err_free_vals:
+ kfree(dev->vals);
+ dev->vals = NULL;
+err_devres_free:
+ devres_free(devres);
+ return error;
}
EXPORT_SYMBOL(input_register_device);
*/
void input_unregister_device(struct input_dev *dev)
{
- struct input_handle *handle, *next;
-
- input_disconnect_device(dev);
-
- mutex_lock(&input_mutex);
-
- list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
- handle->handler->disconnect(handle);
- WARN_ON(!list_empty(&dev->h_list));
-
- del_timer_sync(&dev->timer);
- list_del_init(&dev->node);
-
- input_wakeup_procfs_readers();
-
- mutex_unlock(&input_mutex);
-
- device_unregister(&dev->dev);
+ if (dev->devres_managed) {
+ WARN_ON(devres_destroy(dev->dev.parent,
+ devm_input_device_unregister,
+ devm_input_device_match,
+ dev));
+ __input_unregister_device(dev);
+ /*
+ * We do not do input_put_device() here because it will be done
+ * when 2nd devres fires up.
+ */
+ } else {
+ __input_unregister_device(dev);
+ input_put_device(dev);
+ }
}
EXPORT_SYMBOL(input_unregister_device);
projects / ~andy / linux / blobdiff