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/**

 * input_register_device - register device with input core * @dev: device to be registered * * This function registers device with input core. The device must be * allocated with input_allocate_device() and all it's capabilities * set up before registering. * If function fails the device must be freed with input_free_device(). * 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){	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);	/* KEY_RESERVED is not supposed to be transmitted to userspace. */	__clear_bit(KEY_RESERVED, dev->keybit);	/* Make sure that bitmasks not mentioned in dev->evbit are clean. */	input_cleanse_bitmasks(dev);	packet_size = input_estimate_events_per_packet(dev);	if (dev->hint_events_per_packet < packet_size)		dev->hint_events_per_packet = packet_size;	dev->max_vals = dev->hint_events_per_packet + 2;	dev->vals = kcalloc(dev->max_vals, sizeof(*dev->vals), GFP_KERNEL);	if (!dev->vals) {		error = -ENOMEM;		goto err_devres_free;	}	/*	 * If delay and period are pre-set by the driver, then autorepeating	 * is handled by the driver itself and we don't do it in input.c.	 */	if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD])		input_enable_softrepeat(dev, 250, 33);	if (!dev->getkeycode)		dev->getkeycode = input_default_getkeycode;	if (!dev->setkeycode)		dev->setkeycode = input_default_setkeycode;	error = device_add(&dev->dev);	if (error)		goto err_free_vals;	path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);	pr_info("%s as %s\n",		dev->name ? dev->name : "Unspecified device",		path ? path : "N/A");	kfree(path);	error = mutex_lock_interruptible(&input_mutex);	if (error)		goto err_device_del;	list_add_tail(&dev->node, &input_dev_list);	list_for_each_entry(handler, &input_handler_list, node)		input_attach_handler(dev, handler);	input_wakeup_procfs_readers();	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;}

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