diff options
Diffstat (limited to 'drivers/hid/hidraw.c')
-rw-r--r-- | drivers/hid/hidraw.c | 401 |
1 files changed, 401 insertions, 0 deletions
diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c new file mode 100644 index 000000000000..8503197a8131 --- /dev/null +++ b/drivers/hid/hidraw.c @@ -0,0 +1,401 @@ +/* + * 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/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_SPINLOCK(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); + struct hid_device *dev = hidraw_table[minor]->hid; + __u8 *buf; + int ret = 0; + + if (!dev->hid_output_raw_report) + return -ENODEV; + + if (count > HID_MIN_BUFFER_SIZE) { + printk(KERN_WARNING "hidraw: pid %d passed too large report\n", + current->pid); + return -EINVAL; + } + + if (count < 2) { + printk(KERN_WARNING "hidraw: pid %d passed too short report\n", + current->pid); + 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; + } + + spin_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++) + dev->hid->hid_open(dev->hid); + +out_unlock: + spin_unlock(&minors_lock); +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->hid_close(dev->hid); + else + kfree(list->hidraw); + } + + return 0; +} + +static int hidraw_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) +{ + unsigned int minor = iminor(inode); + struct hidraw *dev = hidraw_table[minor]; + void __user *user_arg = (void __user*) arg; + + switch (cmd) { + case HIDIOCGRDESCSIZE: + if (put_user(dev->hid->rsize, (int __user *)arg)) + return -EFAULT; + return 0; + + case HIDIOCGRDESC: + { + __u32 len; + + if (get_user(len, (int __user *)arg)) + return -EFAULT; + if (copy_to_user(*((__u8 **)(user_arg + + sizeof(__u32))), + dev->hid->rdesc, len)) + return -EFAULT; + return 0; + } + 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))) + return -EFAULT; + + return 0; + } + default: + printk(KERN_EMERG "hidraw: unsupported ioctl() %x\n", + cmd); + } + return -EINVAL; +} + +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, + .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; + + spin_lock(&minors_lock); + + for (minor = 0; minor < HIDRAW_MAX_DEVICES; minor++) { + if (hidraw_table[minor]) + continue; + hidraw_table[minor] = dev; + result = 0; + break; + } + + spin_unlock(&minors_lock); + + if (result) { + kfree(dev); + goto out; + } + + dev->dev = device_create(hidraw_class, NULL, MKDEV(hidraw_major, minor), + "%s%d", "hidraw", minor); + + if (IS_ERR(dev->dev)) { + spin_lock(&minors_lock); + hidraw_table[minor] = NULL; + spin_unlock(&minors_lock); + result = PTR_ERR(dev->dev); + kfree(dev); + goto out; + } + + 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; + + spin_lock(&minors_lock); + hidraw_table[hidraw->minor] = NULL; + spin_unlock(&minors_lock); + + device_destroy(hidraw_class, MKDEV(hidraw_major, hidraw->minor)); + + if (hidraw->open) { + hid->hid_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 __exit 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); + +} |