drivers/hid/hidraw.c - kernel/msm-4.9 - Gitiles

 /*
  * HID raw devices, giving access to raw HID events.
  *
  * In comparison to hiddev, this device does not process the
  * hid events at all (no parsing, no lookups). This lets applications
  * to work on raw hid events as they want to, and avoids a need to
  * use a transport-specific userspace libhid/libusb libraries.
  *
  *  Copyright (c) 2007 Jiri Kosina
  */

 /*
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
  * version 2, as published by the Free Software Foundation.
  *
  * You should have received a copy of the GNU General Public License along with
  * this program; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  */

 #include <linux/fs.h>
 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/cdev.h>
 #include <linux/poll.h>
 #include <linux/device.h>
 #include <linux/major.h>
 #include <linux/hid.h>
 #include <linux/mutex.h>
 #include <linux/smp_lock.h>

 #include <linux/hidraw.h>

 static int hidraw_major;
 static struct cdev hidraw_cdev;
 static struct class *hidraw_class;
 static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
 static DEFINE_MUTEX(minors_lock);

 static ssize_t hidraw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 {
 	struct hidraw_list *list = file->private_data;
 	int ret = 0, len;
 	char *report;
 	DECLARE_WAITQUEUE(wait, current);

 	while (ret == 0) {

 		mutex_lock(&list->read_mutex);

 		if (list->head == list->tail) {
 			add_wait_queue(&list->hidraw->wait, &wait);
 			set_current_state(TASK_INTERRUPTIBLE);

 			while (list->head == list->tail) {
 				if (file->f_flags & O_NONBLOCK) {
 					ret = -EAGAIN;
 					break;
 				}
 				if (signal_pending(current)) {
 					ret = -ERESTARTSYS;
 					break;
 				}
 				if (!list->hidraw->exist) {
 					ret = -EIO;
 					break;
 				}

 				/* allow O_NONBLOCK to work well from other threads */
 				mutex_unlock(&list->read_mutex);
 				schedule();
 				mutex_lock(&list->read_mutex);
 				set_current_state(TASK_INTERRUPTIBLE);
 			}

 			set_current_state(TASK_RUNNING);
 			remove_wait_queue(&list->hidraw->wait, &wait);
 		}

 		if (ret)
 			goto out;

 		report = list->buffer[list->tail].value;
 		len = list->buffer[list->tail].len > count ?
 			count : list->buffer[list->tail].len;

 		if (copy_to_user(buffer, list->buffer[list->tail].value, len)) {
 			ret = -EFAULT;
 			goto out;
 		}
 		ret += len;

 		kfree(list->buffer[list->tail].value);
 		list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
 	}
 out:
 	mutex_unlock(&list->read_mutex);
 	return ret;
 }

 /* the first byte is expected to be a report number */
 static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 {
 	unsigned int minor = iminor(file->f_path.dentry->d_inode);
 	/* FIXME: What stops hidraw_table going NULL */
 	struct hid_device *dev = hidraw_table[minor]->hid;
 	__u8 *buf;
 	int ret = 0;

 	if (!dev->hid_output_raw_report)
 		return -ENODEV;

 	if (count > HID_MAX_BUFFER_SIZE) {
 		printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
 				task_pid_nr(current));
 		return -EINVAL;
 	}

 	if (count < 2) {
 		printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
 				task_pid_nr(current));
 		return -EINVAL;
 	}

 	buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;

 	if (copy_from_user(buf, buffer, count)) {
 		ret = -EFAULT;
 		goto out;
 	}

 	ret = dev->hid_output_raw_report(dev, buf, count);
 out:
 	kfree(buf);
 	return ret;
 }

 static unsigned int hidraw_poll(struct file *file, poll_table *wait)
 {
 	struct hidraw_list *list = file->private_data;

 	poll_wait(file, &list->hidraw->wait, wait);
 	if (list->head != list->tail)
 		return POLLIN | POLLRDNORM;
 	if (!list->hidraw->exist)
 		return POLLERR | POLLHUP;
 	return 0;
 }

 static int hidraw_open(struct inode *inode, struct file *file)
 {
 	unsigned int minor = iminor(inode);
 	struct hidraw *dev;
 	struct hidraw_list *list;
 	int err = 0;

 	if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
 		err = -ENOMEM;
 		goto out;
 	}

 	lock_kernel();
 	mutex_lock(&minors_lock);
 	if (!hidraw_table[minor]) {
 		printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n",
 				minor);
 		kfree(list);
 		err = -ENODEV;
 		goto out_unlock;
 	}

 	list->hidraw = hidraw_table[minor];
 	mutex_init(&list->read_mutex);
 	list_add_tail(&list->node, &hidraw_table[minor]->list);
 	file->private_data = list;

 	dev = hidraw_table[minor];
 	if (!dev->open++) {
 		err = dev->hid->ll_driver->open(dev->hid);
 		if (err < 0)
 			dev->open--;
 	}

 out_unlock:
 	mutex_unlock(&minors_lock);
 	unlock_kernel();
 out:
 	return err;

 }

 static int hidraw_release(struct inode * inode, struct file * file)
 {
 	unsigned int minor = iminor(inode);
 	struct hidraw *dev;
 	struct hidraw_list *list = file->private_data;

 	if (!hidraw_table[minor]) {
 		printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n",
 				minor);
 		return -ENODEV;
 	}

 	list_del(&list->node);
 	dev = hidraw_table[minor];
 	if (!dev->open--) {
 		if (list->hidraw->exist)
 			dev->hid->ll_driver->close(dev->hid);
 		else
 			kfree(list->hidraw);
 	}

 	kfree(list);

 	return 0;
 }

 static long hidraw_ioctl(struct file *file, unsigned int cmd,
 							unsigned long arg)
 {
 	struct inode *inode = file->f_path.dentry->d_inode;
 	unsigned int minor = iminor(inode);
 	long ret = 0;
 	/* FIXME: What stops hidraw_table going NULL */
 	struct hidraw *dev = hidraw_table[minor];
 	void __user *user_arg = (void __user*) arg;

 	lock_kernel();
 	switch (cmd) {
 		case HIDIOCGRDESCSIZE:
 			if (put_user(dev->hid->rsize, (int __user *)arg))
 				ret = -EFAULT;
 			break;

 		case HIDIOCGRDESC:
 			{
 				__u32 len;

 				if (get_user(len, (int __user *)arg))
 					ret = -EFAULT;
 				else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
 					ret = -EINVAL;
 				else if (copy_to_user(user_arg + offsetof(
 					struct hidraw_report_descriptor,
 					value[0]),
 					dev->hid->rdesc,
 					min(dev->hid->rsize, len)))
 					ret = -EFAULT;
 				break;
 			}
 		case HIDIOCGRAWINFO:
 			{
 				struct hidraw_devinfo dinfo;

 				dinfo.bustype = dev->hid->bus;
 				dinfo.vendor = dev->hid->vendor;
 				dinfo.product = dev->hid->product;
 				if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
 					ret = -EFAULT;
 				break;
 			}
 		default:
 			ret = -ENOTTY;
 	}
 	unlock_kernel();
 	return ret;
 }

 static const struct file_operations hidraw_ops = {
 	.owner =        THIS_MODULE,
 	.read =         hidraw_read,
 	.write =        hidraw_write,
 	.poll =         hidraw_poll,
 	.open =         hidraw_open,
 	.release =      hidraw_release,
 	.unlocked_ioctl = hidraw_ioctl,
 };

 void hidraw_report_event(struct hid_device *hid, u8 *data, int len)
 {
 	struct hidraw *dev = hid->hidraw;
 	struct hidraw_list *list;

 	list_for_each_entry(list, &dev->list, node) {
 		list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC);
 		list->buffer[list->head].len = len;
 		list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
 		kill_fasync(&list->fasync, SIGIO, POLL_IN);
 	}

 	wake_up_interruptible(&dev->wait);
 }
 EXPORT_SYMBOL_GPL(hidraw_report_event);

 int hidraw_connect(struct hid_device *hid)
 {
 	int minor, result;
 	struct hidraw *dev;

 	/* TODO currently we accept any HID device. This should later
 	 * probably be fixed to accept only those devices which provide
 	 * non-input applications
 	 */

 	dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
 	if (!dev)
 		return -ENOMEM;

 	result = -EINVAL;

 	mutex_lock(&minors_lock);

 	for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
 		if (hidraw_table[minor])
 			continue;
 		hidraw_table[minor] = dev;
 		result = 0;
 		break;
 	}

 	if (result) {
 		mutex_unlock(&minors_lock);
 		kfree(dev);
 		goto out;
 	}

 	dev->dev = device_create(hidraw_class, NULL, MKDEV(hidraw_major, minor),
 				 NULL, "%s%d", "hidraw", minor);

 	if (IS_ERR(dev->dev)) {
 		hidraw_table[minor] = NULL;
 		mutex_unlock(&minors_lock);
 		result = PTR_ERR(dev->dev);
 		kfree(dev);
 		goto out;
 	}

 	mutex_unlock(&minors_lock);
 	init_waitqueue_head(&dev->wait);
 	INIT_LIST_HEAD(&dev->list);

 	dev->hid = hid;
 	dev->minor = minor;

 	dev->exist = 1;
 	hid->hidraw = dev;

 out:
 	return result;

 }
 EXPORT_SYMBOL_GPL(hidraw_connect);

 void hidraw_disconnect(struct hid_device *hid)
 {
 	struct hidraw *hidraw = hid->hidraw;

 	hidraw->exist = 0;

 	mutex_lock(&minors_lock);
 	hidraw_table[hidraw->minor] = NULL;
 	mutex_unlock(&minors_lock);

 	device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));

 	if (hidraw->open) {
 		hid->ll_driver->close(hid);
 		wake_up_interruptible(&hidraw->wait);
 	} else {
 		kfree(hidraw);
 	}
 }
 EXPORT_SYMBOL_GPL(hidraw_disconnect);

 int __init hidraw_init(void)
 {
 	int result;
 	dev_t dev_id;

 	result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
 			HIDRAW_MAX_DEVICES, "hidraw");

 	hidraw_major = MAJOR(dev_id);

 	if (result < 0) {
 		printk(KERN_WARNING "hidraw: can't get major number\n");
 		result = 0;
 		goto out;
 	}

 	hidraw_class = class_create(THIS_MODULE, "hidraw");
 	if (IS_ERR(hidraw_class)) {
 		result = PTR_ERR(hidraw_class);
 		unregister_chrdev(hidraw_major, "hidraw");
 		goto out;
 	}

         cdev_init(&hidraw_cdev, &hidraw_ops);
         cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
 out:
 	return result;
 }

 void hidraw_exit(void)
 {
 	dev_t dev_id = MKDEV(hidraw_major, 0);

 	cdev_del(&hidraw_cdev);
 	class_destroy(hidraw_class);
 	unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);

 }
	/*
	* HID raw devices, giving access to raw HID events.
	*
	* In comparison to hiddev, this device does not process the
	* hid events at all (no parsing, no lookups). This lets applications
	* to work on raw hid events as they want to, and avoids a need to
	* use a transport-specific userspace libhid/libusb libraries.
	*
	* Copyright (c) 2007 Jiri Kosina
	*/

	/*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms and conditions of the GNU General Public License,
	* version 2, as published by the Free Software Foundation.
	*
	* You should have received a copy of the GNU General Public License along with
	* this program; if not, write to the Free Software Foundation, Inc.,
	* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
	*/

	#include <linux/fs.h>
	#include <linux/module.h>
	#include <linux/errno.h>
	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/cdev.h>
	#include <linux/poll.h>
	#include <linux/device.h>
	#include <linux/major.h>
	#include <linux/hid.h>
	#include <linux/mutex.h>
	#include <linux/smp_lock.h>

	#include <linux/hidraw.h>

	static int hidraw_major;
	static struct cdev hidraw_cdev;
	static struct class *hidraw_class;
	static struct hidraw *hidraw_table[HIDRAW_MAX_DEVICES];
	static DEFINE_MUTEX(minors_lock);

	static ssize_t hidraw_read(struct file file, char __user buffer, size_t count, loff_t *ppos)
	{
	struct hidraw_list *list = file->private_data;
	int ret = 0, len;
	char *report;
	DECLARE_WAITQUEUE(wait, current);

	while (ret == 0) {

	mutex_lock(&list->read_mutex);

	if (list->head == list->tail) {
	add_wait_queue(&list->hidraw->wait, &wait);
	set_current_state(TASK_INTERRUPTIBLE);

	while (list->head == list->tail) {
	if (file->f_flags & O_NONBLOCK) {
	ret = -EAGAIN;
	break;
	}
	if (signal_pending(current)) {
	ret = -ERESTARTSYS;
	break;
	}
	if (!list->hidraw->exist) {
	ret = -EIO;
	break;
	}

	/* allow O_NONBLOCK to work well from other threads */
	mutex_unlock(&list->read_mutex);
	schedule();
	mutex_lock(&list->read_mutex);
	set_current_state(TASK_INTERRUPTIBLE);
	}

	set_current_state(TASK_RUNNING);
	remove_wait_queue(&list->hidraw->wait, &wait);
	}

	if (ret)
	goto out;

	report = list->buffer[list->tail].value;
	len = list->buffer[list->tail].len > count ?
	count : list->buffer[list->tail].len;

	if (copy_to_user(buffer, list->buffer[list->tail].value, len)) {
	ret = -EFAULT;
	goto out;
	}
	ret += len;

	kfree(list->buffer[list->tail].value);
	list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
	}
	out:
	mutex_unlock(&list->read_mutex);
	return ret;
	}

	/* the first byte is expected to be a report number */
	static ssize_t hidraw_write(struct file file, const char __user buffer, size_t count, loff_t *ppos)
	{
	unsigned int minor = iminor(file->f_path.dentry->d_inode);
	/* FIXME: What stops hidraw_table going NULL */
	struct hid_device *dev = hidraw_table[minor]->hid;
	__u8 *buf;
	int ret = 0;

	if (!dev->hid_output_raw_report)
	return -ENODEV;

	if (count > HID_MAX_BUFFER_SIZE) {
	printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
	task_pid_nr(current));
	return -EINVAL;
	}

	if (count < 2) {
	printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
	task_pid_nr(current));
	return -EINVAL;
	}

	buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
	if (!buf)
	return -ENOMEM;

	if (copy_from_user(buf, buffer, count)) {
	ret = -EFAULT;
	goto out;
	}

	ret = dev->hid_output_raw_report(dev, buf, count);
	out:
	kfree(buf);
	return ret;
	}

	static unsigned int hidraw_poll(struct file file, poll_table wait)
	{
	struct hidraw_list *list = file->private_data;

	poll_wait(file, &list->hidraw->wait, wait);
	if (list->head != list->tail)
	return POLLIN \| POLLRDNORM;
	if (!list->hidraw->exist)
	return POLLERR \| POLLHUP;
	return 0;
	}

	static int hidraw_open(struct inode inode, struct file file)
	{
	unsigned int minor = iminor(inode);
	struct hidraw *dev;
	struct hidraw_list *list;
	int err = 0;

	if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
	err = -ENOMEM;
	goto out;
	}

	lock_kernel();
	mutex_lock(&minors_lock);
	if (!hidraw_table[minor]) {
	printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n",
	minor);
	kfree(list);
	err = -ENODEV;
	goto out_unlock;
	}

	list->hidraw = hidraw_table[minor];
	mutex_init(&list->read_mutex);
	list_add_tail(&list->node, &hidraw_table[minor]->list);
	file->private_data = list;

	dev = hidraw_table[minor];
	if (!dev->open++) {
	err = dev->hid->ll_driver->open(dev->hid);
	if (err < 0)
	dev->open--;
	}

	out_unlock:
	mutex_unlock(&minors_lock);
	unlock_kernel();
	out:
	return err;

	}

	static int hidraw_release(struct inode * inode, struct file * file)
	{
	unsigned int minor = iminor(inode);
	struct hidraw *dev;
	struct hidraw_list *list = file->private_data;

	if (!hidraw_table[minor]) {
	printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n",
	minor);
	return -ENODEV;
	}

	list_del(&list->node);
	dev = hidraw_table[minor];
	if (!dev->open--) {
	if (list->hidraw->exist)
	dev->hid->ll_driver->close(dev->hid);
	else
	kfree(list->hidraw);
	}

	kfree(list);

	return 0;
	}

	static long hidraw_ioctl(struct file *file, unsigned int cmd,
	unsigned long arg)
	{
	struct inode *inode = file->f_path.dentry->d_inode;
	unsigned int minor = iminor(inode);
	long ret = 0;
	/* FIXME: What stops hidraw_table going NULL */
	struct hidraw *dev = hidraw_table[minor];
	void __user user_arg = (void __user) arg;

	lock_kernel();
	switch (cmd) {
	case HIDIOCGRDESCSIZE:
	if (put_user(dev->hid->rsize, (int __user *)arg))
	ret = -EFAULT;
	break;

	case HIDIOCGRDESC:
	{
	__u32 len;

	if (get_user(len, (int __user *)arg))
	ret = -EFAULT;
	else if (len > HID_MAX_DESCRIPTOR_SIZE - 1)
	ret = -EINVAL;
	else if (copy_to_user(user_arg + offsetof(
	struct hidraw_report_descriptor,
	value[0]),
	dev->hid->rdesc,
	min(dev->hid->rsize, len)))
	ret = -EFAULT;
	break;
	}
	case HIDIOCGRAWINFO:
	{
	struct hidraw_devinfo dinfo;

	dinfo.bustype = dev->hid->bus;
	dinfo.vendor = dev->hid->vendor;
	dinfo.product = dev->hid->product;
	if (copy_to_user(user_arg, &dinfo, sizeof(dinfo)))
	ret = -EFAULT;
	break;
	}
	default:
	ret = -ENOTTY;
	}
	unlock_kernel();
	return ret;
	}

	static const struct file_operations hidraw_ops = {
	.owner = THIS_MODULE,
	.read = hidraw_read,
	.write = hidraw_write,
	.poll = hidraw_poll,
	.open = hidraw_open,
	.release = hidraw_release,
	.unlocked_ioctl = hidraw_ioctl,
	};

	void hidraw_report_event(struct hid_device hid, u8 data, int len)
	{
	struct hidraw *dev = hid->hidraw;
	struct hidraw_list *list;

	list_for_each_entry(list, &dev->list, node) {
	list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC);
	list->buffer[list->head].len = len;
	list->head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
	kill_fasync(&list->fasync, SIGIO, POLL_IN);
	}

	wake_up_interruptible(&dev->wait);
	}
	EXPORT_SYMBOL_GPL(hidraw_report_event);

	int hidraw_connect(struct hid_device *hid)
	{
	int minor, result;
	struct hidraw *dev;

	/* TODO currently we accept any HID device. This should later
	* probably be fixed to accept only those devices which provide
	* non-input applications
	*/

	dev = kzalloc(sizeof(struct hidraw), GFP_KERNEL);
	if (!dev)
	return -ENOMEM;

	result = -EINVAL;

	mutex_lock(&minors_lock);

	for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) {
	if (hidraw_table[minor])
	continue;
	hidraw_table[minor] = dev;
	result = 0;
	break;
	}

	if (result) {
	mutex_unlock(&minors_lock);
	kfree(dev);
	goto out;
	}

	dev->dev = device_create(hidraw_class, NULL, MKDEV(hidraw_major, minor),
	NULL, "%s%d", "hidraw", minor);

	if (IS_ERR(dev->dev)) {
	hidraw_table[minor] = NULL;
	mutex_unlock(&minors_lock);
	result = PTR_ERR(dev->dev);
	kfree(dev);
	goto out;
	}

	mutex_unlock(&minors_lock);
	init_waitqueue_head(&dev->wait);
	INIT_LIST_HEAD(&dev->list);

	dev->hid = hid;
	dev->minor = minor;

	dev->exist = 1;
	hid->hidraw = dev;

	out:
	return result;

	}
	EXPORT_SYMBOL_GPL(hidraw_connect);

	void hidraw_disconnect(struct hid_device *hid)
	{
	struct hidraw *hidraw = hid->hidraw;

	hidraw->exist = 0;

	mutex_lock(&minors_lock);
	hidraw_table[hidraw->minor] = NULL;
	mutex_unlock(&minors_lock);

	device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor));

	if (hidraw->open) {
	hid->ll_driver->close(hid);
	wake_up_interruptible(&hidraw->wait);
	} else {
	kfree(hidraw);
	}
	}
	EXPORT_SYMBOL_GPL(hidraw_disconnect);

	int __init hidraw_init(void)
	{
	int result;
	dev_t dev_id;

	result = alloc_chrdev_region(&dev_id, HIDRAW_FIRST_MINOR,
	HIDRAW_MAX_DEVICES, "hidraw");

	hidraw_major = MAJOR(dev_id);

	if (result < 0) {
	printk(KERN_WARNING "hidraw: can't get major number\n");
	result = 0;
	goto out;
	}

	hidraw_class = class_create(THIS_MODULE, "hidraw");
	if (IS_ERR(hidraw_class)) {
	result = PTR_ERR(hidraw_class);
	unregister_chrdev(hidraw_major, "hidraw");
	goto out;
	}

	cdev_init(&hidraw_cdev, &hidraw_ops);
	cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
	out:
	return result;
	}

	void hidraw_exit(void)
	{
	dev_t dev_id = MKDEV(hidraw_major, 0);

	cdev_del(&hidraw_cdev);
	class_destroy(hidraw_class);
	unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);

	}