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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222// SPDX-License-Identifier: GPL-2.0-only/* * Support for polling mode for input devices. */
#include <linux/device.h>#include <linux/export.h>#include <linux/input.h>#include <linux/jiffies.h>#include <linux/mutex.h>#include <linux/slab.h>#include <linux/types.h>#include <linux/workqueue.h>#include "input-poller.h"
struct input_dev_poller { void (*poll)(struct input_dev *dev);
unsigned int poll_interval; /* msec */ unsigned int poll_interval_max; /* msec */ unsigned int poll_interval_min; /* msec */
struct input_dev *input; struct delayed_work work;};
static void input_dev_poller_queue_work(struct input_dev_poller *poller){ unsigned long delay;
delay = msecs_to_jiffies(poller->poll_interval); if (delay >= HZ) delay = round_jiffies_relative(delay);
queue_delayed_work(system_freezable_wq, &poller->work, delay);}
static void input_dev_poller_work(struct work_struct *work){ struct input_dev_poller *poller = container_of(work, struct input_dev_poller, work.work);
poller->poll(poller->input); input_dev_poller_queue_work(poller);}
void input_dev_poller_finalize(struct input_dev_poller *poller){ if (!poller->poll_interval) poller->poll_interval = 500; if (!poller->poll_interval_max) poller->poll_interval_max = poller->poll_interval;}
void input_dev_poller_start(struct input_dev_poller *poller){ /* Only start polling if polling is enabled */ if (poller->poll_interval > 0) { poller->poll(poller->input); input_dev_poller_queue_work(poller); }}
void input_dev_poller_stop(struct input_dev_poller *poller){ cancel_delayed_work_sync(&poller->work);}
int input_setup_polling(struct input_dev *dev, void (*poll_fn)(struct input_dev *dev)){ struct input_dev_poller *poller;
poller = kzalloc_obj(*poller); if (!poller) { /* * We want to show message even though kzalloc() may have * printed backtrace as knowing what instance of input * device we were dealing with is helpful. */ dev_err(dev->dev.parent ?: &dev->dev, "%s: unable to allocate poller structure\n", __func__); return -ENOMEM; }
INIT_DELAYED_WORK(&poller->work, input_dev_poller_work); poller->input = dev; poller->poll = poll_fn;
dev->poller = poller; return 0;}EXPORT_SYMBOL(input_setup_polling);
static bool input_dev_ensure_poller(struct input_dev *dev){ if (!dev->poller) { dev_err(dev->dev.parent ?: &dev->dev, "poller structure has not been set up\n"); return false; }
return true;}
void input_set_poll_interval(struct input_dev *dev, unsigned int interval){ if (input_dev_ensure_poller(dev)) dev->poller->poll_interval = interval;}EXPORT_SYMBOL(input_set_poll_interval);
void input_set_min_poll_interval(struct input_dev *dev, unsigned int interval){ if (input_dev_ensure_poller(dev)) dev->poller->poll_interval_min = interval;}EXPORT_SYMBOL(input_set_min_poll_interval);
void input_set_max_poll_interval(struct input_dev *dev, unsigned int interval){ if (input_dev_ensure_poller(dev)) dev->poller->poll_interval_max = interval;}EXPORT_SYMBOL(input_set_max_poll_interval);
int input_get_poll_interval(struct input_dev *dev){ if (!dev->poller) return -EINVAL;
return dev->poller->poll_interval;}EXPORT_SYMBOL(input_get_poll_interval);
/* SYSFS interface */
static ssize_t input_dev_get_poll_interval(struct device *dev, struct device_attribute *attr, char *buf){ struct input_dev *input = to_input_dev(dev);
return sprintf(buf, "%d\n", input->poller->poll_interval);}
static ssize_t input_dev_set_poll_interval(struct device *dev, struct device_attribute *attr, const char *buf, size_t count){ struct input_dev *input = to_input_dev(dev); struct input_dev_poller *poller = input->poller; unsigned int interval; int err;
err = kstrtouint(buf, 0, &interval); if (err) return err;
if (interval < poller->poll_interval_min) return -EINVAL;
if (interval > poller->poll_interval_max) return -EINVAL;
guard(mutex)(&input->mutex);
poller->poll_interval = interval;
if (input_device_enabled(input)) { cancel_delayed_work_sync(&poller->work); if (poller->poll_interval > 0) input_dev_poller_queue_work(poller); }
return count;}
static DEVICE_ATTR(poll, 0644, input_dev_get_poll_interval, input_dev_set_poll_interval);
static ssize_t input_dev_get_poll_max(struct device *dev, struct device_attribute *attr, char *buf){ struct input_dev *input = to_input_dev(dev);
return sprintf(buf, "%d\n", input->poller->poll_interval_max);}
static DEVICE_ATTR(max, 0444, input_dev_get_poll_max, NULL);
static ssize_t input_dev_get_poll_min(struct device *dev, struct device_attribute *attr, char *buf){ struct input_dev *input = to_input_dev(dev);
return sprintf(buf, "%d\n", input->poller->poll_interval_min);}
static DEVICE_ATTR(min, 0444, input_dev_get_poll_min, NULL);
static umode_t input_poller_attrs_visible(struct kobject *kobj, struct attribute *attr, int n){ struct device *dev = kobj_to_dev(kobj); struct input_dev *input = to_input_dev(dev);
return input->poller ? attr->mode : 0;}
static struct attribute *input_poller_attrs[] = { &dev_attr_poll.attr, &dev_attr_max.attr, &dev_attr_min.attr, NULL};
struct attribute_group input_poller_attribute_group = { .is_visible = input_poller_attrs_visible, .attrs = input_poller_attrs,};