--- /dev/null
+/*
+ * 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) 2007-2014 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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#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/slab.h>
+#include <linux/hid.h>
+#include <linux/mutex.h>
+#include <linux/sched.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;
+ DECLARE_WAITQUEUE(wait, current);
+
+ mutex_lock(&list->read_mutex);
+
+ while (ret == 0) {
+ if (list->head == list->tail) {
+ add_wait_queue(&list->hidraw->wait, &wait);
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ while (list->head == list->tail) {
+ if (signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+ if (!list->hidraw->exist) {
+ ret = -EIO;
+ break;
+ }
+ if (file->f_flags & O_NONBLOCK) {
+ ret = -EAGAIN;
+ 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;
+
+ len = list->buffer[list->tail].len > count ?
+ count : list->buffer[list->tail].len;
+
+ if (list->buffer[list->tail].value) {
+ if (copy_to_user(buffer, list->buffer[list->tail].value, len)) {
+ ret = -EFAULT;
+ goto out;
+ }
+ ret = len;
+ }
+
+ kfree(list->buffer[list->tail].value);
+ list->buffer[list->tail].value = NULL;
+ list->tail = (list->tail + 1) & (HIDRAW_BUFFER_SIZE - 1);
+ }
+out:
+ mutex_unlock(&list->read_mutex);
+ return ret;
+}
+
+/*
+ * The first byte of the report buffer is expected to be a report number.
+ *
+ * This function is to be called with the minors_lock mutex held.
+ */
+static ssize_t hidraw_send_report(struct file *file, const char __user *buffer, size_t count, unsigned char report_type)
+{
+ unsigned int minor = iminor(file_inode(file));
+ struct hid_device *dev;
+ __u8 *buf;
+ int ret = 0;
+
+ if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ dev = hidraw_table[minor]->hid;
+
+
+ if (count > HID_MAX_BUFFER_SIZE) {
+ hid_warn(dev, "pid %d passed too large report\n",
+ task_pid_nr(current));
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (count < 2) {
+ hid_warn(dev, "pid %d passed too short report\n",
+ task_pid_nr(current));
+ ret = -EINVAL;
+ goto out;
+ }
+
+ buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
+ if (!buf) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (copy_from_user(buf, buffer, count)) {
+ ret = -EFAULT;
+ goto out_free;
+ }
+
+ if ((report_type == HID_OUTPUT_REPORT) &&
+ !(dev->quirks & HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP)) {
+ ret = hid_hw_output_report(dev, buf, count);
+ /*
+ * compatibility with old implementation of USB-HID and I2C-HID:
+ * if the device does not support receiving output reports,
+ * on an interrupt endpoint, fallback to SET_REPORT HID command.
+ */
+ if (ret != -ENOSYS)
+ goto out_free;
+ }
+
+ ret = hid_hw_raw_request(dev, buf[0], buf, count, report_type,
+ HID_REQ_SET_REPORT);
+
+out_free:
+ kfree(buf);
+out:
+ return ret;
+}
+
+static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
+{
+ ssize_t ret;
+ mutex_lock(&minors_lock);
+ ret = hidraw_send_report(file, buffer, count, HID_OUTPUT_REPORT);
+ mutex_unlock(&minors_lock);
+ return ret;
+}
+
+
+/*
+ * This function performs a Get_Report transfer over the control endpoint
+ * per section 7.2.1 of the HID specification, version 1.1. The first byte
+ * of buffer is the report number to request, or 0x0 if the defice does not
+ * use numbered reports. The report_type parameter can be HID_FEATURE_REPORT
+ * or HID_INPUT_REPORT.
+ *
+ * This function is to be called with the minors_lock mutex held.
+ */
+static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t count, unsigned char report_type)
+{
+ unsigned int minor = iminor(file_inode(file));
+ struct hid_device *dev;
+ __u8 *buf;
+ int ret = 0, len;
+ unsigned char report_number;
+
+ dev = hidraw_table[minor]->hid;
+
+ if (!dev->ll_driver->raw_request) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ if (count > HID_MAX_BUFFER_SIZE) {
+ printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
+ task_pid_nr(current));
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (count < 2) {
+ printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
+ task_pid_nr(current));
+ ret = -EINVAL;
+ goto out;
+ }
+
+ buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
+ if (!buf) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /*
+ * Read the first byte from the user. This is the report number,
+ * which is passed to hid_hw_raw_request().
+ */
+ if (copy_from_user(&report_number, buffer, 1)) {
+ ret = -EFAULT;
+ goto out_free;
+ }
+
+ ret = hid_hw_raw_request(dev, report_number, buf, count, report_type,
+ HID_REQ_GET_REPORT);
+
+ if (ret < 0)
+ goto out_free;
+
+ len = (ret < count) ? ret : count;
+
+ if (copy_to_user(buffer, buf, len)) {
+ ret = -EFAULT;
+ goto out_free;
+ }
+
+ ret = len;
+
+out_free:
+ kfree(buf);
+out:
+ 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;
+ unsigned long flags;
+ int err = 0;
+
+ if (!(list = kzalloc(sizeof(struct hidraw_list), GFP_KERNEL))) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ mutex_lock(&minors_lock);
+ if (!hidraw_table[minor] || !hidraw_table[minor]->exist) {
+ err = -ENODEV;
+ goto out_unlock;
+ }
+
+ dev = hidraw_table[minor];
+ if (!dev->open++) {
+ err = hid_hw_power(dev->hid, PM_HINT_FULLON);
+ if (err < 0) {
+ dev->open--;
+ goto out_unlock;
+ }
+
+ err = hid_hw_open(dev->hid);
+ if (err < 0) {
+ hid_hw_power(dev->hid, PM_HINT_NORMAL);
+ dev->open--;
+ goto out_unlock;
+ }
+ }
+
+ list->hidraw = hidraw_table[minor];
+ mutex_init(&list->read_mutex);
+ spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
+ list_add_tail(&list->node, &hidraw_table[minor]->list);
+ spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
+ file->private_data = list;
+out_unlock:
+ mutex_unlock(&minors_lock);
+out:
+ if (err < 0)
+ kfree(list);
+ return err;
+
+}
+
+static int hidraw_fasync(int fd, struct file *file, int on)
+{
+ struct hidraw_list *list = file->private_data;
+
+ return fasync_helper(fd, file, on, &list->fasync);
+}
+
+static void drop_ref(struct hidraw *hidraw, int exists_bit)
+{
+ if (exists_bit) {
+ hidraw->exist = 0;
+ if (hidraw->open) {
+ hid_hw_close(hidraw->hid);
+ wake_up_interruptible(&hidraw->wait);
+ }
+ device_destroy(hidraw_class,
+ MKDEV(hidraw_major, hidraw->minor));
+ } else {
+ --hidraw->open;
+ }
+ if (!hidraw->open) {
+ if (!hidraw->exist) {
+ hidraw_table[hidraw->minor] = NULL;
+ kfree(hidraw);
+ } else {
+ /* close device for last reader */
+ hid_hw_power(hidraw->hid, PM_HINT_NORMAL);
+ hid_hw_close(hidraw->hid);
+ }
+ }
+}
+
+static int hidraw_release(struct inode * inode, struct file * file)
+{
+ unsigned int minor = iminor(inode);
+ struct hidraw_list *list = file->private_data;
+ unsigned long flags;
+
+ mutex_lock(&minors_lock);
+
+ spin_lock_irqsave(&hidraw_table[minor]->list_lock, flags);
+ list_del(&list->node);
+ spin_unlock_irqrestore(&hidraw_table[minor]->list_lock, flags);
+ kfree(list);
+
+ drop_ref(hidraw_table[minor], 0);
+
+ mutex_unlock(&minors_lock);
+ return 0;
+}
+
+static long hidraw_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct inode *inode = file_inode(file);
+ unsigned int minor = iminor(inode);
+ long ret = 0;
+ struct hidraw *dev;
+ void __user *user_arg = (void __user*) arg;
+
+ mutex_lock(&minors_lock);
+ dev = hidraw_table[minor];
+ if (!dev) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ 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') {
+ ret = -EINVAL;
+ break;
+ }
+
+ if (_IOC_NR(cmd) == _IOC_NR(HIDIOCSFEATURE(0))) {
+ int len = _IOC_SIZE(cmd);
+ ret = hidraw_send_report(file, user_arg, len, HID_FEATURE_REPORT);
+ break;
+ }
+ if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGFEATURE(0))) {
+ int len = _IOC_SIZE(cmd);
+ ret = hidraw_get_report(file, user_arg, len, HID_FEATURE_REPORT);
+ break;
+ }
+
+ /* Begin Read-only ioctls. */
+ if (_IOC_DIR(cmd) != _IOC_READ) {
+ ret = -EINVAL;
+ break;
+ }
+
+ if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGRAWNAME(0))) {
+ int 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 = 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;
+ }
+out:
+ mutex_unlock(&minors_lock);
+ 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,
+ .fasync = hidraw_fasync,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = hidraw_ioctl,
+#endif
+ .llseek = noop_llseek,
+};
+
+int hidraw_report_event(struct hid_device *hid, u8 *data, int len)
+{
+ struct hidraw *dev = hid->hidraw;
+ struct hidraw_list *list;
+ int ret = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->list_lock, flags);
+ list_for_each_entry(list, &dev->list, node) {
+ int new_head = (list->head + 1) & (HIDRAW_BUFFER_SIZE - 1);
+
+ if (new_head == list->tail)
+ continue;
+
+ if (!(list->buffer[list->head].value = kmemdup(data, len, GFP_ATOMIC))) {
+ ret = -ENOMEM;
+ break;
+ }
+ list->buffer[list->head].len = len;
+ list->head = new_head;
+ kill_fasync(&list->fasync, SIGIO, POLL_IN);
+ }
+ spin_unlock_irqrestore(&dev->list_lock, flags);
+
+ wake_up_interruptible(&dev->wait);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(hidraw_report_event);
+
+int hidraw_connect(struct hid_device *hid)
+{
+ int minor, result;
+ struct hidraw *dev;
+
+ /* we accept any HID device, all 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;
+ }
+
+ init_waitqueue_head(&dev->wait);
+ spin_lock_init(&dev->list_lock);
+ INIT_LIST_HEAD(&dev->list);
+
+ dev->hid = hid;
+ dev->minor = minor;
+
+ dev->exist = 1;
+ hid->hidraw = dev;
+
+ mutex_unlock(&minors_lock);
+out:
+ return result;
+
+}
+EXPORT_SYMBOL_GPL(hidraw_connect);
+
+void hidraw_disconnect(struct hid_device *hid)
+{
+ struct hidraw *hidraw = hid->hidraw;
+
+ mutex_lock(&minors_lock);
+
+ drop_ref(hidraw, 1);
+
+ mutex_unlock(&minors_lock);
+}
+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) {
+ pr_warn("can't get major number\n");
+ goto out;
+ }
+
+ hidraw_class = class_create(THIS_MODULE, "hidraw");
+ if (IS_ERR(hidraw_class)) {
+ result = PTR_ERR(hidraw_class);
+ goto error_cdev;
+ }
+
+ cdev_init(&hidraw_cdev, &hidraw_ops);
+ result = cdev_add(&hidraw_cdev, dev_id, HIDRAW_MAX_DEVICES);
+ if (result < 0)
+ goto error_class;
+
+ printk(KERN_INFO "hidraw: raw HID events driver (C) Jiri Kosina\n");
+out:
+ return result;
+
+error_class:
+ class_destroy(hidraw_class);
+error_cdev:
+ unregister_chrdev_region(dev_id, HIDRAW_MAX_DEVICES);
+ goto out;
+}
+
+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);
+
+}
Code Review / kvmfornfv.git / blobdiff