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362 lines
9.1 KiB
362 lines
9.1 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Generic implementation of a polled input device |
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* Copyright (c) 2007 Dmitry Torokhov |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/jiffies.h> |
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#include <linux/slab.h> |
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#include <linux/mutex.h> |
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#include <linux/workqueue.h> |
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#include <linux/module.h> |
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#include <linux/input-polldev.h> |
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MODULE_AUTHOR("Dmitry Torokhov <[email protected]>"); |
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MODULE_DESCRIPTION("Generic implementation of a polled input device"); |
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MODULE_LICENSE("GPL v2"); |
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static void input_polldev_queue_work(struct input_polled_dev *dev) |
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{ |
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unsigned long delay; |
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delay = msecs_to_jiffies(dev->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, &dev->work, delay); |
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} |
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static void input_polled_device_work(struct work_struct *work) |
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{ |
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struct input_polled_dev *dev = |
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container_of(work, struct input_polled_dev, work.work); |
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dev->poll(dev); |
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input_polldev_queue_work(dev); |
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} |
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static int input_open_polled_device(struct input_dev *input) |
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{ |
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struct input_polled_dev *dev = input_get_drvdata(input); |
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if (dev->open) |
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dev->open(dev); |
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/* Only start polling if polling is enabled */ |
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if (dev->poll_interval > 0) { |
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dev->poll(dev); |
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input_polldev_queue_work(dev); |
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} |
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return 0; |
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} |
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static void input_close_polled_device(struct input_dev *input) |
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{ |
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struct input_polled_dev *dev = input_get_drvdata(input); |
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cancel_delayed_work_sync(&dev->work); |
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if (dev->close) |
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dev->close(dev); |
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} |
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/* SYSFS interface */ |
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static ssize_t input_polldev_get_poll(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct input_polled_dev *polldev = dev_get_drvdata(dev); |
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return sprintf(buf, "%d\n", polldev->poll_interval); |
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} |
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static ssize_t input_polldev_set_poll(struct device *dev, |
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struct device_attribute *attr, const char *buf, |
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size_t count) |
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{ |
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struct input_polled_dev *polldev = dev_get_drvdata(dev); |
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struct input_dev *input = polldev->input; |
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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 < polldev->poll_interval_min) |
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return -EINVAL; |
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if (interval > polldev->poll_interval_max) |
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return -EINVAL; |
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mutex_lock(&input->mutex); |
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polldev->poll_interval = interval; |
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if (input->users) { |
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cancel_delayed_work_sync(&polldev->work); |
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if (polldev->poll_interval > 0) |
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input_polldev_queue_work(polldev); |
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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, S_IRUGO | S_IWUSR, input_polldev_get_poll, |
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input_polldev_set_poll); |
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static ssize_t input_polldev_get_max(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct input_polled_dev *polldev = dev_get_drvdata(dev); |
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return sprintf(buf, "%d\n", polldev->poll_interval_max); |
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} |
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static DEVICE_ATTR(max, S_IRUGO, input_polldev_get_max, NULL); |
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static ssize_t input_polldev_get_min(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct input_polled_dev *polldev = dev_get_drvdata(dev); |
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return sprintf(buf, "%d\n", polldev->poll_interval_min); |
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} |
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static DEVICE_ATTR(min, S_IRUGO, input_polldev_get_min, NULL); |
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static struct attribute *sysfs_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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static struct attribute_group input_polldev_attribute_group = { |
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.attrs = sysfs_attrs |
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}; |
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static const struct attribute_group *input_polldev_attribute_groups[] = { |
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&input_polldev_attribute_group, |
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NULL |
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}; |
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/** |
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* input_allocate_polled_device - allocate memory for polled device |
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* |
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* The function allocates memory for a polled device and also |
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* for an input device associated with this polled device. |
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*/ |
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struct input_polled_dev *input_allocate_polled_device(void) |
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{ |
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struct input_polled_dev *dev; |
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dev = kzalloc(sizeof(struct input_polled_dev), GFP_KERNEL); |
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if (!dev) |
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return NULL; |
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dev->input = input_allocate_device(); |
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if (!dev->input) { |
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kfree(dev); |
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return NULL; |
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} |
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return dev; |
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} |
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EXPORT_SYMBOL(input_allocate_polled_device); |
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struct input_polled_devres { |
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struct input_polled_dev *polldev; |
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}; |
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static int devm_input_polldev_match(struct device *dev, void *res, void *data) |
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{ |
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struct input_polled_devres *devres = res; |
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return devres->polldev == data; |
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} |
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static void devm_input_polldev_release(struct device *dev, void *res) |
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{ |
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struct input_polled_devres *devres = res; |
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struct input_polled_dev *polldev = devres->polldev; |
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dev_dbg(dev, "%s: dropping reference/freeing %s\n", |
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__func__, dev_name(&polldev->input->dev)); |
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input_put_device(polldev->input); |
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kfree(polldev); |
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} |
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static void devm_input_polldev_unregister(struct device *dev, void *res) |
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{ |
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struct input_polled_devres *devres = res; |
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struct input_polled_dev *polldev = devres->polldev; |
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dev_dbg(dev, "%s: unregistering device %s\n", |
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__func__, dev_name(&polldev->input->dev)); |
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input_unregister_device(polldev->input); |
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/* |
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* Note that we are still holding extra reference to the input |
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* device so it will stick around until devm_input_polldev_release() |
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* is called. |
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*/ |
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} |
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/** |
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* devm_input_allocate_polled_device - allocate managed polled device |
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* @dev: device owning the polled device being created |
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* |
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* Returns prepared &struct input_polled_dev or %NULL. |
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* |
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* Managed polled input devices do not need to be explicitly unregistered |
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* or freed as it will be done automatically when owner device unbinds |
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* from * its driver (or binding fails). Once such managed polled device |
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* is allocated, it is ready to be set up and registered in the same |
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* fashion as regular polled input devices (using |
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* input_register_polled_device() function). |
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* |
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* If you want to manually unregister and free such managed polled devices, |
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* it can be still done by calling input_unregister_polled_device() and |
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* input_free_polled_device(), although it is rarely needed. |
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* |
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* NOTE: the owner device is set up as parent of input device and users |
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* should not override it. |
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*/ |
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struct input_polled_dev *devm_input_allocate_polled_device(struct device *dev) |
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{ |
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struct input_polled_dev *polldev; |
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struct input_polled_devres *devres; |
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devres = devres_alloc(devm_input_polldev_release, sizeof(*devres), |
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GFP_KERNEL); |
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if (!devres) |
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return NULL; |
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polldev = input_allocate_polled_device(); |
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if (!polldev) { |
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devres_free(devres); |
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return NULL; |
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} |
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polldev->input->dev.parent = dev; |
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polldev->devres_managed = true; |
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devres->polldev = polldev; |
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devres_add(dev, devres); |
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return polldev; |
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} |
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EXPORT_SYMBOL(devm_input_allocate_polled_device); |
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/** |
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* input_free_polled_device - free memory allocated for polled device |
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* @dev: device to free |
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* |
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* The function frees memory allocated for polling device and drops |
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* reference to the associated input device. |
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*/ |
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void input_free_polled_device(struct input_polled_dev *dev) |
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{ |
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if (dev) { |
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if (dev->devres_managed) |
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WARN_ON(devres_destroy(dev->input->dev.parent, |
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devm_input_polldev_release, |
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devm_input_polldev_match, |
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dev)); |
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input_put_device(dev->input); |
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kfree(dev); |
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} |
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} |
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EXPORT_SYMBOL(input_free_polled_device); |
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/** |
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* input_register_polled_device - register polled device |
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* @dev: device to register |
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* |
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* The function registers previously initialized polled input device |
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* with input layer. The device should be allocated with call to |
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* input_allocate_polled_device(). Callers should also set up poll() |
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* method and set up capabilities (id, name, phys, bits) of the |
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* corresponding input_dev structure. |
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*/ |
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int input_register_polled_device(struct input_polled_dev *dev) |
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{ |
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struct input_polled_devres *devres = NULL; |
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struct input_dev *input = dev->input; |
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int error; |
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if (dev->devres_managed) { |
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devres = devres_alloc(devm_input_polldev_unregister, |
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sizeof(*devres), GFP_KERNEL); |
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if (!devres) |
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return -ENOMEM; |
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devres->polldev = dev; |
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} |
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input_set_drvdata(input, dev); |
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INIT_DELAYED_WORK(&dev->work, input_polled_device_work); |
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if (!dev->poll_interval) |
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dev->poll_interval = 500; |
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if (!dev->poll_interval_max) |
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dev->poll_interval_max = dev->poll_interval; |
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input->open = input_open_polled_device; |
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input->close = input_close_polled_device; |
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input->dev.groups = input_polldev_attribute_groups; |
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error = input_register_device(input); |
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if (error) { |
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devres_free(devres); |
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return error; |
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} |
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/* |
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* Take extra reference to the underlying input device so |
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* that it survives call to input_unregister_polled_device() |
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* and is deleted only after input_free_polled_device() |
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* has been invoked. This is needed to ease task of freeing |
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* sparse keymaps. |
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*/ |
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input_get_device(input); |
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if (dev->devres_managed) { |
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dev_dbg(input->dev.parent, "%s: registering %s with devres.\n", |
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__func__, dev_name(&input->dev)); |
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devres_add(input->dev.parent, devres); |
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} |
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return 0; |
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} |
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EXPORT_SYMBOL(input_register_polled_device); |
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/** |
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* input_unregister_polled_device - unregister polled device |
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* @dev: device to unregister |
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* |
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* The function unregisters previously registered polled input |
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* device from input layer. Polling is stopped and device is |
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* ready to be freed with call to input_free_polled_device(). |
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*/ |
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void input_unregister_polled_device(struct input_polled_dev *dev) |
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{ |
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if (dev->devres_managed) |
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WARN_ON(devres_destroy(dev->input->dev.parent, |
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devm_input_polldev_unregister, |
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devm_input_polldev_match, |
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dev)); |
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input_unregister_device(dev->input); |
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} |
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EXPORT_SYMBOL(input_unregister_polled_device);
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