drivers/input/input-polldev.c - kernel/quantenna - Git at Google

 /*
  * Generic implementation of a polled input device

  * Copyright (c) 2007 Dmitry Torokhov
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published by
  * the Free Software Foundation.
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/jiffies.h>
 #include <linux/slab.h>
 #include <linux/mutex.h>
 #include <linux/workqueue.h>
 #include <linux/module.h>
 #include <linux/input-polldev.h>

 MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
 MODULE_DESCRIPTION("Generic implementation of a polled input device");
 MODULE_LICENSE("GPL v2");
 MODULE_VERSION("0.1");

 static void input_polldev_queue_work(struct input_polled_dev *dev)
 {
 	unsigned long delay;

 	delay = msecs_to_jiffies(dev->poll_interval);
 	if (delay >= HZ)
 		delay = round_jiffies_relative(delay);

 	queue_delayed_work(system_freezable_wq, &dev->work, delay);
 }

 static void input_polled_device_work(struct work_struct *work)
 {
 	struct input_polled_dev *dev =
 		container_of(work, struct input_polled_dev, work.work);

 	dev->poll(dev);
 	input_polldev_queue_work(dev);
 }

 static int input_open_polled_device(struct input_dev *input)
 {
 	struct input_polled_dev *dev = input_get_drvdata(input);

 	if (dev->open)
 		dev->open(dev);

 	/* Only start polling if polling is enabled */
 	if (dev->poll_interval > 0) {
 		dev->poll(dev);
 		input_polldev_queue_work(dev);
 	}

 	return 0;
 }

 static void input_close_polled_device(struct input_dev *input)
 {
 	struct input_polled_dev *dev = input_get_drvdata(input);

 	cancel_delayed_work_sync(&dev->work);

 	if (dev->close)
 		dev->close(dev);
 }

 /* SYSFS interface */

 static ssize_t input_polldev_get_poll(struct device *dev,
 				      struct device_attribute *attr, char *buf)
 {
 	struct input_polled_dev *polldev = dev_get_drvdata(dev);

 	return sprintf(buf, "%d\n", polldev->poll_interval);
 }

 static ssize_t input_polldev_set_poll(struct device *dev,
 				struct device_attribute *attr, const char *buf,
 				size_t count)
 {
 	struct input_polled_dev *polldev = dev_get_drvdata(dev);
 	struct input_dev *input = polldev->input;
 	unsigned int interval;
 	int err;

 	err = kstrtouint(buf, 0, &interval);
 	if (err)
 		return err;

 	if (interval < polldev->poll_interval_min)
 		return -EINVAL;

 	if (interval > polldev->poll_interval_max)
 		return -EINVAL;

 	mutex_lock(&input->mutex);

 	polldev->poll_interval = interval;

 	if (input->users) {
 		cancel_delayed_work_sync(&polldev->work);
 		if (polldev->poll_interval > 0)
 			input_polldev_queue_work(polldev);
 	}

 	mutex_unlock(&input->mutex);

 	return count;
 }

 static DEVICE_ATTR(poll, S_IRUGO | S_IWUSR, input_polldev_get_poll,
 					    input_polldev_set_poll);


 static ssize_t input_polldev_get_max(struct device *dev,
 				     struct device_attribute *attr, char *buf)
 {
 	struct input_polled_dev *polldev = dev_get_drvdata(dev);

 	return sprintf(buf, "%d\n", polldev->poll_interval_max);
 }

 static DEVICE_ATTR(max, S_IRUGO, input_polldev_get_max, NULL);

 static ssize_t input_polldev_get_min(struct device *dev,
 				     struct device_attribute *attr, char *buf)
 {
 	struct input_polled_dev *polldev = dev_get_drvdata(dev);

 	return sprintf(buf, "%d\n", polldev->poll_interval_min);
 }

 static DEVICE_ATTR(min, S_IRUGO, input_polldev_get_min, NULL);

 static struct attribute *sysfs_attrs[] = {
 	&dev_attr_poll.attr,
 	&dev_attr_max.attr,
 	&dev_attr_min.attr,
 	NULL
 };

 static struct attribute_group input_polldev_attribute_group = {
 	.attrs = sysfs_attrs
 };

 static const struct attribute_group *input_polldev_attribute_groups[] = {
 	&input_polldev_attribute_group,
 	NULL
 };

 /**
  * input_allocate_polled_device - allocate memory for polled device
  *
  * The function allocates memory for a polled device and also
  * for an input device associated with this polled device.
  */
 struct input_polled_dev *input_allocate_polled_device(void)
 {
 	struct input_polled_dev *dev;

 	dev = kzalloc(sizeof(struct input_polled_dev), GFP_KERNEL);
 	if (!dev)
 		return NULL;

 	dev->input = input_allocate_device();
 	if (!dev->input) {
 		kfree(dev);
 		return NULL;
 	}

 	return dev;
 }
 EXPORT_SYMBOL(input_allocate_polled_device);

 struct input_polled_devres {
 	struct input_polled_dev *polldev;
 };

 static int devm_input_polldev_match(struct device *dev, void *res, void *data)
 {
 	struct input_polled_devres *devres = res;

 	return devres->polldev == data;
 }

 static void devm_input_polldev_release(struct device *dev, void *res)
 {
 	struct input_polled_devres *devres = res;
 	struct input_polled_dev *polldev = devres->polldev;

 	dev_dbg(dev, "%s: dropping reference/freeing %s\n",
 		__func__, dev_name(&polldev->input->dev));

 	input_put_device(polldev->input);
 	kfree(polldev);
 }

 static void devm_input_polldev_unregister(struct device *dev, void *res)
 {
 	struct input_polled_devres *devres = res;
 	struct input_polled_dev *polldev = devres->polldev;

 	dev_dbg(dev, "%s: unregistering device %s\n",
 		__func__, dev_name(&polldev->input->dev));
 	input_unregister_device(polldev->input);

 	/*
 	 * Note that we are still holding extra reference to the input
 	 * device so it will stick around until devm_input_polldev_release()
 	 * is called.
 	 */
 }

 /**
  * devm_input_allocate_polled_device - allocate managed polled device
  * @dev: device owning the polled device being created
  *
  * Returns prepared &struct input_polled_dev or %NULL.
  *
  * Managed polled input devices do not need to be explicitly unregistered
  * or freed as it will be done automatically when owner device unbinds
  * from * its driver (or binding fails). Once such managed polled device
  * is allocated, it is ready to be set up and registered in the same
  * fashion as regular polled input devices (using
  * input_register_polled_device() function).
  *
  * If you want to manually unregister and free such managed polled devices,
  * it can be still done by calling input_unregister_polled_device() and
  * input_free_polled_device(), although it is rarely needed.
  *
  * NOTE: the owner device is set up as parent of input device and users
  * should not override it.
  */
 struct input_polled_dev *devm_input_allocate_polled_device(struct device *dev)
 {
 	struct input_polled_dev *polldev;
 	struct input_polled_devres *devres;

 	devres = devres_alloc(devm_input_polldev_release, sizeof(*devres),
 			      GFP_KERNEL);
 	if (!devres)
 		return NULL;

 	polldev = input_allocate_polled_device();
 	if (!polldev) {
 		devres_free(devres);
 		return NULL;
 	}

 	polldev->input->dev.parent = dev;
 	polldev->devres_managed = true;

 	devres->polldev = polldev;
 	devres_add(dev, devres);

 	return polldev;
 }
 EXPORT_SYMBOL(devm_input_allocate_polled_device);

 /**
  * input_free_polled_device - free memory allocated for polled device
  * @dev: device to free
  *
  * The function frees memory allocated for polling device and drops
  * reference to the associated input device.
  */
 void input_free_polled_device(struct input_polled_dev *dev)
 {
 	if (dev) {
 		if (dev->devres_managed)
 			WARN_ON(devres_destroy(dev->input->dev.parent,
 						devm_input_polldev_release,
 						devm_input_polldev_match,
 						dev));
 		input_put_device(dev->input);
 		kfree(dev);
 	}
 }
 EXPORT_SYMBOL(input_free_polled_device);

 /**
  * input_register_polled_device - register polled device
  * @dev: device to register
  *
  * The function registers previously initialized polled input device
  * with input layer. The device should be allocated with call to
  * input_allocate_polled_device(). Callers should also set up poll()
  * method and set up capabilities (id, name, phys, bits) of the
  * corresponding input_dev structure.
  */
 int input_register_polled_device(struct input_polled_dev *dev)
 {
 	struct input_polled_devres *devres = NULL;
 	struct input_dev *input = dev->input;
 	int error;

 	if (dev->devres_managed) {
 		devres = devres_alloc(devm_input_polldev_unregister,
 				      sizeof(*devres), GFP_KERNEL);
 		if (!devres)
 			return -ENOMEM;

 		devres->polldev = dev;
 	}

 	input_set_drvdata(input, dev);
 	INIT_DELAYED_WORK(&dev->work, input_polled_device_work);

 	if (!dev->poll_interval)
 		dev->poll_interval = 500;
 	if (!dev->poll_interval_max)
 		dev->poll_interval_max = dev->poll_interval;

 	input->open = input_open_polled_device;
 	input->close = input_close_polled_device;

 	input->dev.groups = input_polldev_attribute_groups;

 	error = input_register_device(input);
 	if (error) {
 		devres_free(devres);
 		return error;
 	}

 	/*
 	 * Take extra reference to the underlying input device so
 	 * that it survives call to input_unregister_polled_device()
 	 * and is deleted only after input_free_polled_device()
 	 * has been invoked. This is needed to ease task of freeing
 	 * sparse keymaps.
 	 */
 	input_get_device(input);

 	if (dev->devres_managed) {
 		dev_dbg(input->dev.parent, "%s: registering %s with devres.\n",
 			__func__, dev_name(&input->dev));
 		devres_add(input->dev.parent, devres);
 	}

 	return 0;
 }
 EXPORT_SYMBOL(input_register_polled_device);

 /**
  * input_unregister_polled_device - unregister polled device
  * @dev: device to unregister
  *
  * The function unregisters previously registered polled input
  * device from input layer. Polling is stopped and device is
  * ready to be freed with call to input_free_polled_device().
  */
 void input_unregister_polled_device(struct input_polled_dev *dev)
 {
 	if (dev->devres_managed)
 		WARN_ON(devres_destroy(dev->input->dev.parent,
 					devm_input_polldev_unregister,
 					devm_input_polldev_match,
 					dev));

 	input_unregister_device(dev->input);
 }
 EXPORT_SYMBOL(input_unregister_polled_device);
	/*
	* Generic implementation of a polled input device

	* Copyright (c) 2007 Dmitry Torokhov
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 as published by
	* the Free Software Foundation.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/jiffies.h>
	#include <linux/slab.h>
	#include <linux/mutex.h>
	#include <linux/workqueue.h>
	#include <linux/module.h>
	#include <linux/input-polldev.h>

	MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
	MODULE_DESCRIPTION("Generic implementation of a polled input device");
	MODULE_LICENSE("GPL v2");
	MODULE_VERSION("0.1");

	static void input_polldev_queue_work(struct input_polled_dev *dev)
	{
	unsigned long delay;

	delay = msecs_to_jiffies(dev->poll_interval);
	if (delay >= HZ)
	delay = round_jiffies_relative(delay);

	queue_delayed_work(system_freezable_wq, &dev->work, delay);
	}

	static void input_polled_device_work(struct work_struct *work)
	{
	struct input_polled_dev *dev =
	container_of(work, struct input_polled_dev, work.work);

	dev->poll(dev);
	input_polldev_queue_work(dev);
	}

	static int input_open_polled_device(struct input_dev *input)
	{
	struct input_polled_dev *dev = input_get_drvdata(input);

	if (dev->open)
	dev->open(dev);

	/* Only start polling if polling is enabled */
	if (dev->poll_interval > 0) {
	dev->poll(dev);
	input_polldev_queue_work(dev);
	}

	return 0;
	}

	static void input_close_polled_device(struct input_dev *input)
	{
	struct input_polled_dev *dev = input_get_drvdata(input);

	cancel_delayed_work_sync(&dev->work);

	if (dev->close)
	dev->close(dev);
	}

	/* SYSFS interface */

	static ssize_t input_polldev_get_poll(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct input_polled_dev *polldev = dev_get_drvdata(dev);

	return sprintf(buf, "%d\n", polldev->poll_interval);
	}

	static ssize_t input_polldev_set_poll(struct device *dev,
	struct device_attribute attr, const char buf,
	size_t count)
	{
	struct input_polled_dev *polldev = dev_get_drvdata(dev);
	struct input_dev *input = polldev->input;
	unsigned int interval;
	int err;

	err = kstrtouint(buf, 0, &interval);
	if (err)
	return err;

	if (interval < polldev->poll_interval_min)
	return -EINVAL;

	if (interval > polldev->poll_interval_max)
	return -EINVAL;

	mutex_lock(&input->mutex);

	polldev->poll_interval = interval;

	if (input->users) {
	cancel_delayed_work_sync(&polldev->work);
	if (polldev->poll_interval > 0)
	input_polldev_queue_work(polldev);
	}

	mutex_unlock(&input->mutex);

	return count;
	}

	static DEVICE_ATTR(poll, S_IRUGO \| S_IWUSR, input_polldev_get_poll,
	input_polldev_set_poll);


	static ssize_t input_polldev_get_max(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct input_polled_dev *polldev = dev_get_drvdata(dev);

	return sprintf(buf, "%d\n", polldev->poll_interval_max);
	}

	static DEVICE_ATTR(max, S_IRUGO, input_polldev_get_max, NULL);

	static ssize_t input_polldev_get_min(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct input_polled_dev *polldev = dev_get_drvdata(dev);

	return sprintf(buf, "%d\n", polldev->poll_interval_min);
	}

	static DEVICE_ATTR(min, S_IRUGO, input_polldev_get_min, NULL);

	static struct attribute *sysfs_attrs[] = {
	&dev_attr_poll.attr,
	&dev_attr_max.attr,
	&dev_attr_min.attr,
	NULL
	};

	static struct attribute_group input_polldev_attribute_group = {
	.attrs = sysfs_attrs
	};

	static const struct attribute_group *input_polldev_attribute_groups[] = {
	&input_polldev_attribute_group,
	NULL
	};

	/**
	* input_allocate_polled_device - allocate memory for polled device
	*
	* The function allocates memory for a polled device and also
	* for an input device associated with this polled device.
	*/
	struct input_polled_dev *input_allocate_polled_device(void)
	{
	struct input_polled_dev *dev;

	dev = kzalloc(sizeof(struct input_polled_dev), GFP_KERNEL);
	if (!dev)
	return NULL;

	dev->input = input_allocate_device();
	if (!dev->input) {
	kfree(dev);
	return NULL;
	}

	return dev;
	}
	EXPORT_SYMBOL(input_allocate_polled_device);

	struct input_polled_devres {
	struct input_polled_dev *polldev;
	};

	static int devm_input_polldev_match(struct device dev, void res, void *data)
	{
	struct input_polled_devres *devres = res;

	return devres->polldev == data;
	}

	static void devm_input_polldev_release(struct device dev, void res)
	{
	struct input_polled_devres *devres = res;
	struct input_polled_dev *polldev = devres->polldev;

	dev_dbg(dev, "%s: dropping reference/freeing %s\n",
	__func__, dev_name(&polldev->input->dev));

	input_put_device(polldev->input);
	kfree(polldev);
	}

	static void devm_input_polldev_unregister(struct device dev, void res)
	{
	struct input_polled_devres *devres = res;
	struct input_polled_dev *polldev = devres->polldev;

	dev_dbg(dev, "%s: unregistering device %s\n",
	__func__, dev_name(&polldev->input->dev));
	input_unregister_device(polldev->input);

	/*
	* Note that we are still holding extra reference to the input
	* device so it will stick around until devm_input_polldev_release()
	* is called.
	*/
	}

	/**
	* devm_input_allocate_polled_device - allocate managed polled device
	* @dev: device owning the polled device being created
	*
	* Returns prepared &struct input_polled_dev or %NULL.
	*
	* Managed polled input devices do not need to be explicitly unregistered
	* or freed as it will be done automatically when owner device unbinds
	* from * its driver (or binding fails). Once such managed polled device
	* is allocated, it is ready to be set up and registered in the same
	* fashion as regular polled input devices (using
	* input_register_polled_device() function).
	*
	* If you want to manually unregister and free such managed polled devices,
	* it can be still done by calling input_unregister_polled_device() and
	* input_free_polled_device(), although it is rarely needed.
	*
	* NOTE: the owner device is set up as parent of input device and users
	* should not override it.
	*/
	struct input_polled_dev devm_input_allocate_polled_device(struct device dev)
	{
	struct input_polled_dev *polldev;
	struct input_polled_devres *devres;

	devres = devres_alloc(devm_input_polldev_release, sizeof(*devres),
	GFP_KERNEL);
	if (!devres)
	return NULL;

	polldev = input_allocate_polled_device();
	if (!polldev) {
	devres_free(devres);
	return NULL;
	}

	polldev->input->dev.parent = dev;
	polldev->devres_managed = true;

	devres->polldev = polldev;
	devres_add(dev, devres);

	return polldev;
	}
	EXPORT_SYMBOL(devm_input_allocate_polled_device);

	/**
	* input_free_polled_device - free memory allocated for polled device
	* @dev: device to free
	*
	* The function frees memory allocated for polling device and drops
	* reference to the associated input device.
	*/
	void input_free_polled_device(struct input_polled_dev *dev)
	{
	if (dev) {
	if (dev->devres_managed)
	WARN_ON(devres_destroy(dev->input->dev.parent,
	devm_input_polldev_release,
	devm_input_polldev_match,
	dev));
	input_put_device(dev->input);
	kfree(dev);
	}
	}
	EXPORT_SYMBOL(input_free_polled_device);

	/**
	* input_register_polled_device - register polled device
	* @dev: device to register
	*
	* The function registers previously initialized polled input device
	* with input layer. The device should be allocated with call to
	* input_allocate_polled_device(). Callers should also set up poll()
	* method and set up capabilities (id, name, phys, bits) of the
	* corresponding input_dev structure.
	*/
	int input_register_polled_device(struct input_polled_dev *dev)
	{
	struct input_polled_devres *devres = NULL;
	struct input_dev *input = dev->input;
	int error;

	if (dev->devres_managed) {
	devres = devres_alloc(devm_input_polldev_unregister,
	sizeof(*devres), GFP_KERNEL);
	if (!devres)
	return -ENOMEM;

	devres->polldev = dev;
	}

	input_set_drvdata(input, dev);
	INIT_DELAYED_WORK(&dev->work, input_polled_device_work);

	if (!dev->poll_interval)
	dev->poll_interval = 500;
	if (!dev->poll_interval_max)
	dev->poll_interval_max = dev->poll_interval;

	input->open = input_open_polled_device;
	input->close = input_close_polled_device;

	input->dev.groups = input_polldev_attribute_groups;

	error = input_register_device(input);
	if (error) {
	devres_free(devres);
	return error;
	}

	/*
	* Take extra reference to the underlying input device so
	* that it survives call to input_unregister_polled_device()
	* and is deleted only after input_free_polled_device()
	* has been invoked. This is needed to ease task of freeing
	* sparse keymaps.
	*/
	input_get_device(input);

	if (dev->devres_managed) {
	dev_dbg(input->dev.parent, "%s: registering %s with devres.\n",
	__func__, dev_name(&input->dev));
	devres_add(input->dev.parent, devres);
	}

	return 0;
	}
	EXPORT_SYMBOL(input_register_polled_device);

	/**
	* input_unregister_polled_device - unregister polled device
	* @dev: device to unregister
	*
	* The function unregisters previously registered polled input
	* device from input layer. Polling is stopped and device is
	* ready to be freed with call to input_free_polled_device().
	*/
	void input_unregister_polled_device(struct input_polled_dev *dev)
	{
	if (dev->devres_managed)
	WARN_ON(devres_destroy(dev->input->dev.parent,
	devm_input_polldev_unregister,
	devm_input_polldev_match,
	dev));

	input_unregister_device(dev->input);
	}
	EXPORT_SYMBOL(input_unregister_polled_device);