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