| /* |
| * 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++) { |
| if (dev->hid->ll_driver->power) { |
| err = dev->hid->ll_driver->power(dev->hid, PM_HINT_FULLON); |
| if (err < 0) |
| goto out_unlock; |
| } |
| err = dev->hid->ll_driver->open(dev->hid); |
| if (err < 0) { |
| if (dev->hid->ll_driver->power) |
| dev->hid->ll_driver->power(dev->hid, PM_HINT_NORMAL); |
| 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) { |
| if (dev->hid->ll_driver->power) |
| dev->hid->ll_driver->power(dev->hid, PM_HINT_NORMAL); |
| 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: |
| { |
| struct hid_device *hid = dev->hid; |
| if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ) { |
| ret = -EINVAL; |
| break; |
| } |
| |
| if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) { |
| int len; |
| if (!hid->name) |
| return 0; |
| len = strlen(hid->name) + 1; |
| if (len > _IOC_SIZE(cmd)) |
| len = _IOC_SIZE(cmd); |
| ret = copy_to_user(user_arg, hid->name, len) ? |
| -EFAULT : len; |
| break; |
| } |
| |
| if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWPHYS(0))) { |
| int len; |
| if (!hid->phys) |
| return 0; |
| len = strlen(hid->phys) + 1; |
| if (len > _IOC_SIZE(cmd)) |
| len = _IOC_SIZE(cmd); |
| ret = copy_to_user(user_arg, hid->phys, len) ? |
| -EFAULT : len; |
| break; |
| } |
| } |
| |
| 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, &hid->dev, 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); |
| |
| } |