18c2ecf20Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0-only
28c2ecf20Sopenharmony_ci/*
38c2ecf20Sopenharmony_ci * Support for polling mode for input devices.
48c2ecf20Sopenharmony_ci */
58c2ecf20Sopenharmony_ci
68c2ecf20Sopenharmony_ci#include <linux/device.h>
78c2ecf20Sopenharmony_ci#include <linux/input.h>
88c2ecf20Sopenharmony_ci#include <linux/jiffies.h>
98c2ecf20Sopenharmony_ci#include <linux/mutex.h>
108c2ecf20Sopenharmony_ci#include <linux/slab.h>
118c2ecf20Sopenharmony_ci#include <linux/types.h>
128c2ecf20Sopenharmony_ci#include <linux/workqueue.h>
138c2ecf20Sopenharmony_ci#include "input-poller.h"
148c2ecf20Sopenharmony_ci
158c2ecf20Sopenharmony_cistruct input_dev_poller {
168c2ecf20Sopenharmony_ci	void (*poll)(struct input_dev *dev);
178c2ecf20Sopenharmony_ci
188c2ecf20Sopenharmony_ci	unsigned int poll_interval; /* msec */
198c2ecf20Sopenharmony_ci	unsigned int poll_interval_max; /* msec */
208c2ecf20Sopenharmony_ci	unsigned int poll_interval_min; /* msec */
218c2ecf20Sopenharmony_ci
228c2ecf20Sopenharmony_ci	struct input_dev *input;
238c2ecf20Sopenharmony_ci	struct delayed_work work;
248c2ecf20Sopenharmony_ci};
258c2ecf20Sopenharmony_ci
268c2ecf20Sopenharmony_cistatic void input_dev_poller_queue_work(struct input_dev_poller *poller)
278c2ecf20Sopenharmony_ci{
288c2ecf20Sopenharmony_ci	unsigned long delay;
298c2ecf20Sopenharmony_ci
308c2ecf20Sopenharmony_ci	delay = msecs_to_jiffies(poller->poll_interval);
318c2ecf20Sopenharmony_ci	if (delay >= HZ)
328c2ecf20Sopenharmony_ci		delay = round_jiffies_relative(delay);
338c2ecf20Sopenharmony_ci
348c2ecf20Sopenharmony_ci	queue_delayed_work(system_freezable_wq, &poller->work, delay);
358c2ecf20Sopenharmony_ci}
368c2ecf20Sopenharmony_ci
378c2ecf20Sopenharmony_cistatic void input_dev_poller_work(struct work_struct *work)
388c2ecf20Sopenharmony_ci{
398c2ecf20Sopenharmony_ci	struct input_dev_poller *poller =
408c2ecf20Sopenharmony_ci		container_of(work, struct input_dev_poller, work.work);
418c2ecf20Sopenharmony_ci
428c2ecf20Sopenharmony_ci	poller->poll(poller->input);
438c2ecf20Sopenharmony_ci	input_dev_poller_queue_work(poller);
448c2ecf20Sopenharmony_ci}
458c2ecf20Sopenharmony_ci
468c2ecf20Sopenharmony_civoid input_dev_poller_finalize(struct input_dev_poller *poller)
478c2ecf20Sopenharmony_ci{
488c2ecf20Sopenharmony_ci	if (!poller->poll_interval)
498c2ecf20Sopenharmony_ci		poller->poll_interval = 500;
508c2ecf20Sopenharmony_ci	if (!poller->poll_interval_max)
518c2ecf20Sopenharmony_ci		poller->poll_interval_max = poller->poll_interval;
528c2ecf20Sopenharmony_ci}
538c2ecf20Sopenharmony_ci
548c2ecf20Sopenharmony_civoid input_dev_poller_start(struct input_dev_poller *poller)
558c2ecf20Sopenharmony_ci{
568c2ecf20Sopenharmony_ci	/* Only start polling if polling is enabled */
578c2ecf20Sopenharmony_ci	if (poller->poll_interval > 0) {
588c2ecf20Sopenharmony_ci		poller->poll(poller->input);
598c2ecf20Sopenharmony_ci		input_dev_poller_queue_work(poller);
608c2ecf20Sopenharmony_ci	}
618c2ecf20Sopenharmony_ci}
628c2ecf20Sopenharmony_ci
638c2ecf20Sopenharmony_civoid input_dev_poller_stop(struct input_dev_poller *poller)
648c2ecf20Sopenharmony_ci{
658c2ecf20Sopenharmony_ci	cancel_delayed_work_sync(&poller->work);
668c2ecf20Sopenharmony_ci}
678c2ecf20Sopenharmony_ci
688c2ecf20Sopenharmony_ciint input_setup_polling(struct input_dev *dev,
698c2ecf20Sopenharmony_ci			void (*poll_fn)(struct input_dev *dev))
708c2ecf20Sopenharmony_ci{
718c2ecf20Sopenharmony_ci	struct input_dev_poller *poller;
728c2ecf20Sopenharmony_ci
738c2ecf20Sopenharmony_ci	poller = kzalloc(sizeof(*poller), GFP_KERNEL);
748c2ecf20Sopenharmony_ci	if (!poller) {
758c2ecf20Sopenharmony_ci		/*
768c2ecf20Sopenharmony_ci		 * We want to show message even though kzalloc() may have
778c2ecf20Sopenharmony_ci		 * printed backtrace as knowing what instance of input
788c2ecf20Sopenharmony_ci		 * device we were dealing with is helpful.
798c2ecf20Sopenharmony_ci		 */
808c2ecf20Sopenharmony_ci		dev_err(dev->dev.parent ?: &dev->dev,
818c2ecf20Sopenharmony_ci			"%s: unable to allocate poller structure\n", __func__);
828c2ecf20Sopenharmony_ci		return -ENOMEM;
838c2ecf20Sopenharmony_ci	}
848c2ecf20Sopenharmony_ci
858c2ecf20Sopenharmony_ci	INIT_DELAYED_WORK(&poller->work, input_dev_poller_work);
868c2ecf20Sopenharmony_ci	poller->input = dev;
878c2ecf20Sopenharmony_ci	poller->poll = poll_fn;
888c2ecf20Sopenharmony_ci
898c2ecf20Sopenharmony_ci	dev->poller = poller;
908c2ecf20Sopenharmony_ci	return 0;
918c2ecf20Sopenharmony_ci}
928c2ecf20Sopenharmony_ciEXPORT_SYMBOL(input_setup_polling);
938c2ecf20Sopenharmony_ci
948c2ecf20Sopenharmony_cistatic bool input_dev_ensure_poller(struct input_dev *dev)
958c2ecf20Sopenharmony_ci{
968c2ecf20Sopenharmony_ci	if (!dev->poller) {
978c2ecf20Sopenharmony_ci		dev_err(dev->dev.parent ?: &dev->dev,
988c2ecf20Sopenharmony_ci			"poller structure has not been set up\n");
998c2ecf20Sopenharmony_ci		return false;
1008c2ecf20Sopenharmony_ci	}
1018c2ecf20Sopenharmony_ci
1028c2ecf20Sopenharmony_ci	return true;
1038c2ecf20Sopenharmony_ci}
1048c2ecf20Sopenharmony_ci
1058c2ecf20Sopenharmony_civoid input_set_poll_interval(struct input_dev *dev, unsigned int interval)
1068c2ecf20Sopenharmony_ci{
1078c2ecf20Sopenharmony_ci	if (input_dev_ensure_poller(dev))
1088c2ecf20Sopenharmony_ci		dev->poller->poll_interval = interval;
1098c2ecf20Sopenharmony_ci}
1108c2ecf20Sopenharmony_ciEXPORT_SYMBOL(input_set_poll_interval);
1118c2ecf20Sopenharmony_ci
1128c2ecf20Sopenharmony_civoid input_set_min_poll_interval(struct input_dev *dev, unsigned int interval)
1138c2ecf20Sopenharmony_ci{
1148c2ecf20Sopenharmony_ci	if (input_dev_ensure_poller(dev))
1158c2ecf20Sopenharmony_ci		dev->poller->poll_interval_min = interval;
1168c2ecf20Sopenharmony_ci}
1178c2ecf20Sopenharmony_ciEXPORT_SYMBOL(input_set_min_poll_interval);
1188c2ecf20Sopenharmony_ci
1198c2ecf20Sopenharmony_civoid input_set_max_poll_interval(struct input_dev *dev, unsigned int interval)
1208c2ecf20Sopenharmony_ci{
1218c2ecf20Sopenharmony_ci	if (input_dev_ensure_poller(dev))
1228c2ecf20Sopenharmony_ci		dev->poller->poll_interval_max = interval;
1238c2ecf20Sopenharmony_ci}
1248c2ecf20Sopenharmony_ciEXPORT_SYMBOL(input_set_max_poll_interval);
1258c2ecf20Sopenharmony_ci
1268c2ecf20Sopenharmony_ciint input_get_poll_interval(struct input_dev *dev)
1278c2ecf20Sopenharmony_ci{
1288c2ecf20Sopenharmony_ci	if (!dev->poller)
1298c2ecf20Sopenharmony_ci		return -EINVAL;
1308c2ecf20Sopenharmony_ci
1318c2ecf20Sopenharmony_ci	return dev->poller->poll_interval;
1328c2ecf20Sopenharmony_ci}
1338c2ecf20Sopenharmony_ciEXPORT_SYMBOL(input_get_poll_interval);
1348c2ecf20Sopenharmony_ci
1358c2ecf20Sopenharmony_ci/* SYSFS interface */
1368c2ecf20Sopenharmony_ci
1378c2ecf20Sopenharmony_cistatic ssize_t input_dev_get_poll_interval(struct device *dev,
1388c2ecf20Sopenharmony_ci					   struct device_attribute *attr,
1398c2ecf20Sopenharmony_ci					   char *buf)
1408c2ecf20Sopenharmony_ci{
1418c2ecf20Sopenharmony_ci	struct input_dev *input = to_input_dev(dev);
1428c2ecf20Sopenharmony_ci
1438c2ecf20Sopenharmony_ci	return sprintf(buf, "%d\n", input->poller->poll_interval);
1448c2ecf20Sopenharmony_ci}
1458c2ecf20Sopenharmony_ci
1468c2ecf20Sopenharmony_cistatic ssize_t input_dev_set_poll_interval(struct device *dev,
1478c2ecf20Sopenharmony_ci					   struct device_attribute *attr,
1488c2ecf20Sopenharmony_ci					   const char *buf, size_t count)
1498c2ecf20Sopenharmony_ci{
1508c2ecf20Sopenharmony_ci	struct input_dev *input = to_input_dev(dev);
1518c2ecf20Sopenharmony_ci	struct input_dev_poller *poller = input->poller;
1528c2ecf20Sopenharmony_ci	unsigned int interval;
1538c2ecf20Sopenharmony_ci	int err;
1548c2ecf20Sopenharmony_ci
1558c2ecf20Sopenharmony_ci	err = kstrtouint(buf, 0, &interval);
1568c2ecf20Sopenharmony_ci	if (err)
1578c2ecf20Sopenharmony_ci		return err;
1588c2ecf20Sopenharmony_ci
1598c2ecf20Sopenharmony_ci	if (interval < poller->poll_interval_min)
1608c2ecf20Sopenharmony_ci		return -EINVAL;
1618c2ecf20Sopenharmony_ci
1628c2ecf20Sopenharmony_ci	if (interval > poller->poll_interval_max)
1638c2ecf20Sopenharmony_ci		return -EINVAL;
1648c2ecf20Sopenharmony_ci
1658c2ecf20Sopenharmony_ci	mutex_lock(&input->mutex);
1668c2ecf20Sopenharmony_ci
1678c2ecf20Sopenharmony_ci	poller->poll_interval = interval;
1688c2ecf20Sopenharmony_ci
1698c2ecf20Sopenharmony_ci	if (input->users) {
1708c2ecf20Sopenharmony_ci		cancel_delayed_work_sync(&poller->work);
1718c2ecf20Sopenharmony_ci		if (poller->poll_interval > 0)
1728c2ecf20Sopenharmony_ci			input_dev_poller_queue_work(poller);
1738c2ecf20Sopenharmony_ci	}
1748c2ecf20Sopenharmony_ci
1758c2ecf20Sopenharmony_ci	mutex_unlock(&input->mutex);
1768c2ecf20Sopenharmony_ci
1778c2ecf20Sopenharmony_ci	return count;
1788c2ecf20Sopenharmony_ci}
1798c2ecf20Sopenharmony_ci
1808c2ecf20Sopenharmony_cistatic DEVICE_ATTR(poll, 0644,
1818c2ecf20Sopenharmony_ci		   input_dev_get_poll_interval, input_dev_set_poll_interval);
1828c2ecf20Sopenharmony_ci
1838c2ecf20Sopenharmony_cistatic ssize_t input_dev_get_poll_max(struct device *dev,
1848c2ecf20Sopenharmony_ci				      struct device_attribute *attr, char *buf)
1858c2ecf20Sopenharmony_ci{
1868c2ecf20Sopenharmony_ci	struct input_dev *input = to_input_dev(dev);
1878c2ecf20Sopenharmony_ci
1888c2ecf20Sopenharmony_ci	return sprintf(buf, "%d\n", input->poller->poll_interval_max);
1898c2ecf20Sopenharmony_ci}
1908c2ecf20Sopenharmony_ci
1918c2ecf20Sopenharmony_cistatic DEVICE_ATTR(max, 0444, input_dev_get_poll_max, NULL);
1928c2ecf20Sopenharmony_ci
1938c2ecf20Sopenharmony_cistatic ssize_t input_dev_get_poll_min(struct device *dev,
1948c2ecf20Sopenharmony_ci				     struct device_attribute *attr, char *buf)
1958c2ecf20Sopenharmony_ci{
1968c2ecf20Sopenharmony_ci	struct input_dev *input = to_input_dev(dev);
1978c2ecf20Sopenharmony_ci
1988c2ecf20Sopenharmony_ci	return sprintf(buf, "%d\n", input->poller->poll_interval_min);
1998c2ecf20Sopenharmony_ci}
2008c2ecf20Sopenharmony_ci
2018c2ecf20Sopenharmony_cistatic DEVICE_ATTR(min, 0444, input_dev_get_poll_min, NULL);
2028c2ecf20Sopenharmony_ci
2038c2ecf20Sopenharmony_cistatic umode_t input_poller_attrs_visible(struct kobject *kobj,
2048c2ecf20Sopenharmony_ci					  struct attribute *attr, int n)
2058c2ecf20Sopenharmony_ci{
2068c2ecf20Sopenharmony_ci	struct device *dev = kobj_to_dev(kobj);
2078c2ecf20Sopenharmony_ci	struct input_dev *input = to_input_dev(dev);
2088c2ecf20Sopenharmony_ci
2098c2ecf20Sopenharmony_ci	return input->poller ? attr->mode : 0;
2108c2ecf20Sopenharmony_ci}
2118c2ecf20Sopenharmony_ci
2128c2ecf20Sopenharmony_cistatic struct attribute *input_poller_attrs[] = {
2138c2ecf20Sopenharmony_ci	&dev_attr_poll.attr,
2148c2ecf20Sopenharmony_ci	&dev_attr_max.attr,
2158c2ecf20Sopenharmony_ci	&dev_attr_min.attr,
2168c2ecf20Sopenharmony_ci	NULL
2178c2ecf20Sopenharmony_ci};
2188c2ecf20Sopenharmony_ci
2198c2ecf20Sopenharmony_cistruct attribute_group input_poller_attribute_group = {
2208c2ecf20Sopenharmony_ci	.is_visible	= input_poller_attrs_visible,
2218c2ecf20Sopenharmony_ci	.attrs		= input_poller_attrs,
2228c2ecf20Sopenharmony_ci};
223