hiddev.c
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上传日期:2013-02-24
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- /*
- * Copyright (c) 2001 Paul Stewart
- * Copyright (c) 2001 Vojtech Pavlik
- *
- * HID char devices, giving access to raw HID device events.
- *
- */
- /*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- * Should you need to contact me, the author, you can do so either by
- * e-mail - mail your message to Paul Stewart <stewart@wetlogic.net>
- */
- #define HIDDEV_MINOR_BASE 96
- #define HIDDEV_MINORS 16
- #define HIDDEV_BUFFER_SIZE 64
- #include <linux/poll.h>
- #include <linux/slab.h>
- #include <linux/module.h>
- #include <linux/init.h>
- #include <linux/smp_lock.h>
- #include <linux/input.h>
- #include <linux/usb.h>
- #include "hid.h"
- #include <linux/hiddev.h>
- struct hiddev {
- int exist;
- int open;
- int minor;
- wait_queue_head_t wait;
- devfs_handle_t devfs;
- struct hid_device *hid;
- struct hiddev_list *list;
- };
- struct hiddev_list {
- struct hiddev_event buffer[HIDDEV_BUFFER_SIZE];
- int head;
- int tail;
- struct fasync_struct *fasync;
- struct hiddev *hiddev;
- struct hiddev_list *next;
- };
- static struct hiddev *hiddev_table[HIDDEV_MINORS];
- static devfs_handle_t hiddev_devfs_handle;
- /*
- * Find a report, given the report's type and ID. The ID can be specified
- * indirectly by REPORT_ID_FIRST (which returns the first report of the given
- * type) or by (REPORT_ID_NEXT | old_id), which returns the next report of the
- * given type which follows old_id.
- */
- static struct hid_report *
- hiddev_lookup_report(struct hid_device *hid, struct hiddev_report_info *rinfo)
- {
- struct hid_report_enum *report_enum;
- struct list_head *list;
- if (rinfo->report_type < HID_REPORT_TYPE_MIN ||
- rinfo->report_type > HID_REPORT_TYPE_MAX) return NULL;
- report_enum = hid->report_enum +
- (rinfo->report_type - HID_REPORT_TYPE_MIN);
- if ((rinfo->report_id & ~HID_REPORT_ID_MASK) != 0) {
- switch (rinfo->report_id & ~HID_REPORT_ID_MASK) {
- case HID_REPORT_ID_FIRST:
- list = report_enum->report_list.next;
- if (list == &report_enum->report_list) return NULL;
- rinfo->report_id = ((struct hid_report *) list)->id;
- break;
- case HID_REPORT_ID_NEXT:
- list = (struct list_head *)
- report_enum->report_id_hash[rinfo->report_id &
- HID_REPORT_ID_MASK];
- if (list == NULL) return NULL;
- list = list->next;
- if (list == &report_enum->report_list) return NULL;
- rinfo->report_id = ((struct hid_report *) list)->id;
- break;
- default:
- return NULL;
- }
- }
- return report_enum->report_id_hash[rinfo->report_id];
- }
- /*
- * Perform an exhaustive search of the report table for a usage, given its
- * type and usage id.
- */
- static struct hid_field *
- hiddev_lookup_usage(struct hid_device *hid, struct hiddev_usage_ref *uref)
- {
- int i, j;
- struct hid_report *report;
- struct hid_report_enum *report_enum;
- struct list_head *list;
- struct hid_field *field;
- if (uref->report_type < HID_REPORT_TYPE_MIN ||
- uref->report_type > HID_REPORT_TYPE_MAX) return NULL;
- report_enum = hid->report_enum +
- (uref->report_type - HID_REPORT_TYPE_MIN);
- list = report_enum->report_list.next;
- while (list != &report_enum->report_list) {
- report = (struct hid_report *) list;
- for (i = 0; i < report->maxfield; i++) {
- field = report->field[i];
- for (j = 0; j < field->maxusage; j++) {
- if (field->usage[j].hid == uref->usage_code) {
- uref->report_id = report->id;
- uref->field_index = i;
- uref->usage_index = j;
- return field;
- }
- }
- }
- list = list->next;
- }
- return NULL;
- }
- /*
- * This is where hid.c calls into hiddev to pass an event that occurred over
- * the interrupt pipe
- */
- void hiddev_hid_event(struct hid_device *hid, unsigned int usage, int value)
- {
- struct hiddev *hiddev = hid->hiddev;
- struct hiddev_list *list = hiddev->list;
- while (list) {
- list->buffer[list->head].hid = usage;
- list->buffer[list->head].value = value;
- list->head = (list->head + 1) & (HIDDEV_BUFFER_SIZE - 1);
- kill_fasync(&list->fasync, SIGIO, POLL_IN);
- list = list->next;
- }
- wake_up_interruptible(&hiddev->wait);
- }
- /*
- * fasync file op
- */
- static int hiddev_fasync(int fd, struct file *file, int on)
- {
- int retval;
- struct hiddev_list *list = file->private_data;
- retval = fasync_helper(fd, file, on, &list->fasync);
- return retval < 0 ? retval : 0;
- }
- /*
- * De-allocate a hiddev structure
- */
- static void hiddev_cleanup(struct hiddev *hiddev)
- {
- devfs_unregister(hiddev->devfs);
- hiddev_table[hiddev->minor] = NULL;
- kfree(hiddev);
- }
- /*
- * release file op
- */
- static int hiddev_release(struct inode * inode, struct file * file)
- {
- struct hiddev_list *list = file->private_data;
- struct hiddev_list **listptr;
- lock_kernel();
- listptr = &list->hiddev->list;
- hiddev_fasync(-1, file, 0);
- while (*listptr && (*listptr != list))
- listptr = &((*listptr)->next);
- *listptr = (*listptr)->next;
- if (!--list->hiddev->open) {
- if (list->hiddev->exist)
- hid_close(list->hiddev->hid);
- else
- hiddev_cleanup(list->hiddev);
- }
- kfree(list);
- unlock_kernel();
- return 0;
- }
- /*
- * open file op
- */
- static int hiddev_open(struct inode * inode, struct file * file) {
- struct hiddev_list *list;
- int i = MINOR(inode->i_rdev) - HIDDEV_MINOR_BASE;
- if (i >= HIDDEV_MINORS || !hiddev_table[i])
- return -ENODEV;
- if (!(list = kmalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
- return -ENOMEM;
- memset(list, 0, sizeof(struct hiddev_list));
- list->hiddev = hiddev_table[i];
- list->next = hiddev_table[i]->list;
- hiddev_table[i]->list = list;
- file->private_data = list;
- if (!list->hiddev->open++)
- if (list->hiddev->exist)
- hid_open(hiddev_table[i]->hid);
- return 0;
- }
- /*
- * "write" file op
- */
- static ssize_t hiddev_write(struct file * file, const char * buffer,
- size_t count, loff_t *ppos)
- {
- return -EINVAL;
- }
- /*
- * "read" file op
- */
- static ssize_t hiddev_read(struct file * file, char * buffer, size_t count,
- loff_t *ppos)
- {
- DECLARE_WAITQUEUE(wait, current);
- struct hiddev_list *list = file->private_data;
- int retval = 0;
- if (list->head == list->tail) {
- add_wait_queue(&list->hiddev->wait, &wait);
- set_current_state(TASK_INTERRUPTIBLE);
- while (list->head == list->tail) {
- if (file->f_flags & O_NONBLOCK) {
- retval = -EAGAIN;
- break;
- }
- if (signal_pending(current)) {
- retval = -ERESTARTSYS;
- break;
- }
- if (!list->hiddev->exist) {
- retval = -EIO;
- break;
- }
- schedule();
- }
- set_current_state(TASK_RUNNING);
- remove_wait_queue(&list->hiddev->wait, &wait);
- }
- if (retval)
- return retval;
- while (list->head != list->tail && retval + sizeof(struct hiddev_event) <= count) {
- if (copy_to_user(buffer + retval, list->buffer + list->tail,
- sizeof(struct hiddev_event))) return -EFAULT;
- list->tail = (list->tail + 1) & (HIDDEV_BUFFER_SIZE - 1);
- retval += sizeof(struct hiddev_event);
- }
- return retval;
- }
- /*
- * "poll" file op
- * No kernel lock - fine
- */
- static unsigned int hiddev_poll(struct file *file, poll_table *wait)
- {
- struct hiddev_list *list = file->private_data;
- poll_wait(file, &list->hiddev->wait, wait);
- if (list->head != list->tail)
- return POLLIN | POLLRDNORM;
- if (!list->hiddev->exist)
- return POLLERR | POLLHUP;
- return 0;
- }
- #define GET_TIMEOUT 3
- #define SET_TIMEOUT 3
- /*
- * "ioctl" file op
- */
- static int hiddev_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg)
- {
- struct hiddev_list *list = file->private_data;
- struct hiddev *hiddev = list->hiddev;
- struct hid_device *hid = hiddev->hid;
- struct usb_device *dev = hid->dev;
- struct hiddev_report_info rinfo;
- struct hiddev_usage_ref uref;
- struct hid_report *report;
- struct hid_field *field;
- if (!hiddev->exist) return -EIO;
- switch (cmd) {
- case HIDIOCGVERSION:
- return put_user(HID_VERSION, (int *) arg);
- case HIDIOCAPPLICATION:
- if (arg < 0 || arg >= hid->maxapplication)
- return -EINVAL;
- return hid->application[arg];
- case HIDIOCGDEVINFO:
- {
- struct hiddev_devinfo dinfo;
- dinfo.bustype = BUS_USB;
- dinfo.busnum = dev->bus->busnum;
- dinfo.devnum = dev->devnum;
- dinfo.ifnum = hid->ifnum;
- dinfo.vendor = dev->descriptor.idVendor;
- dinfo.product = dev->descriptor.idProduct;
- dinfo.version = dev->descriptor.bcdDevice;
- dinfo.num_applications = hid->maxapplication;
- return copy_to_user((void *) arg, &dinfo, sizeof(dinfo));
- }
- case HIDIOCGSTRING:
- {
- int idx, len;
- char *buf;
- if (get_user(idx, (int *) arg))
- return -EFAULT;
- if ((buf = kmalloc(HID_STRING_SIZE, GFP_KERNEL)) == NULL)
- return -ENOMEM;
- if ((len = usb_string(dev, idx, buf, HID_STRING_SIZE-1)) < 0) {
- kfree(buf);
- return -EINVAL;
- }
- if (copy_to_user((void *) (arg+sizeof(int)), buf, len+1)) {
- kfree(buf);
- return -EFAULT;
- }
- kfree(buf);
- return len;
- }
- case HIDIOCINITREPORT:
- hid_init_reports(hid);
- return 0;
- case HIDIOCGREPORT:
- if (copy_from_user(&rinfo, (void *) arg, sizeof(rinfo)))
- return -EFAULT;
- if (rinfo.report_type == HID_REPORT_TYPE_OUTPUT)
- return -EINVAL;
- if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
- return -EINVAL;
- hid_read_report(hid, report);
- return 0;
- case HIDIOCSREPORT:
- if (copy_from_user(&rinfo, (void *) arg, sizeof(rinfo)))
- return -EFAULT;
- if (rinfo.report_type == HID_REPORT_TYPE_INPUT)
- return -EINVAL;
- if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
- return -EINVAL;
- hid_write_report(hid, report);
- return 0;
- case HIDIOCGREPORTINFO:
- if (copy_from_user(&rinfo, (void *) arg, sizeof(rinfo)))
- return -EFAULT;
- if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
- return -EINVAL;
- rinfo.num_fields = report->maxfield;
- return copy_to_user((void *) arg, &rinfo, sizeof(rinfo));
- case HIDIOCGFIELDINFO:
- {
- struct hiddev_field_info finfo;
- if (copy_from_user(&finfo, (void *) arg, sizeof(finfo)))
- return -EFAULT;
- rinfo.report_type = finfo.report_type;
- rinfo.report_id = finfo.report_id;
- if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
- return -EINVAL;
- if (finfo.field_index >= report->maxfield)
- return -EINVAL;
- field = report->field[finfo.field_index];
- memset(&finfo, 0, sizeof(finfo));
- finfo.report_type = rinfo.report_type;
- finfo.report_id = rinfo.report_id;
- finfo.field_index = field->report_count - 1;
- finfo.maxusage = field->maxusage;
- finfo.flags = field->flags;
- finfo.physical = field->physical;
- finfo.logical = field->logical;
- finfo.application = field->application;
- finfo.logical_minimum = field->logical_minimum;
- finfo.logical_maximum = field->logical_maximum;
- finfo.physical_minimum = field->physical_minimum;
- finfo.physical_maximum = field->physical_maximum;
- finfo.unit_exponent = field->unit_exponent;
- finfo.unit = field->unit;
- return copy_to_user((void *) arg, &finfo, sizeof(finfo));
- }
- case HIDIOCGUCODE:
- if (copy_from_user(&uref, (void *) arg, sizeof(uref)))
- return -EFAULT;
- rinfo.report_type = uref.report_type;
- rinfo.report_id = uref.report_id;
- if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
- return -EINVAL;
- if (uref.field_index >= report->maxfield)
- return -EINVAL;
- field = report->field[uref.field_index];
- if (uref.usage_index >= field->maxusage)
- return -EINVAL;
- uref.usage_code = field->usage[uref.usage_index].hid;
- return copy_to_user((void *) arg, &uref, sizeof(uref));
- case HIDIOCGUSAGE:
- if (copy_from_user(&uref, (void *) arg, sizeof(uref)))
- return -EFAULT;
- if (uref.report_id == HID_REPORT_ID_UNKNOWN) {
- field = hiddev_lookup_usage(hid, &uref);
- if (field == NULL)
- return -EINVAL;
- } else {
- rinfo.report_type = uref.report_type;
- rinfo.report_id = uref.report_id;
- if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
- return -EINVAL;
- if (uref.field_index >= report->maxfield)
- return -EINVAL;
- field = report->field[uref.field_index];
- if (uref.usage_index >= field->maxusage)
- return -EINVAL;
- }
- uref.value = field->value[uref.usage_index];
- return copy_to_user((void *) arg, &uref, sizeof(uref));
- case HIDIOCSUSAGE:
- if (copy_from_user(&uref, (void *) arg, sizeof(uref)))
- return -EFAULT;
- if (uref.report_type == HID_REPORT_TYPE_INPUT)
- return -EINVAL;
- if (uref.report_id == HID_REPORT_ID_UNKNOWN) {
- field = hiddev_lookup_usage(hid, &uref);
- if (field == NULL)
- return -EINVAL;
- } else {
- rinfo.report_type = uref.report_type;
- rinfo.report_id = uref.report_id;
- if ((report = hiddev_lookup_report(hid, &rinfo)) == NULL)
- return -EINVAL;
- if (uref.field_index >= report->maxfield)
- return -EINVAL;
- field = report->field[uref.field_index];
- if (uref.usage_index >= field->maxusage)
- return -EINVAL;
- }
- field->value[uref.usage_index] = uref.value;
- return 0;
- default:
- if (_IOC_TYPE(cmd) != 'H' || _IOC_DIR(cmd) != _IOC_READ)
- return -EINVAL;
- if (_IOC_NR(cmd) == _IOC_NR(HIDIOCGNAME(0))) {
- int len;
- if (!hid->name) return 0;
- len = strlen(hid->name) + 1;
- if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
- return copy_to_user((char *) arg, hid->name, len) ?
- -EFAULT : len;
- }
- }
- return -EINVAL;
- }
- static struct file_operations hiddev_fops = {
- owner: THIS_MODULE,
- read: hiddev_read,
- write: hiddev_write,
- poll: hiddev_poll,
- open: hiddev_open,
- release: hiddev_release,
- ioctl: hiddev_ioctl,
- fasync: hiddev_fasync,
- };
- /*
- * This is where hid.c calls us to connect a hid device to the hiddev driver
- */
- int hiddev_connect(struct hid_device *hid)
- {
- struct hiddev *hiddev;
- int minor, i;
- char devfs_name[16];
- for (i = 0; i < hid->maxapplication; i++)
- if (!IS_INPUT_APPLICATION(hid->application[i]))
- break;
- if (i == hid->maxapplication)
- return -1;
- for (minor = 0; minor < HIDDEV_MINORS && hiddev_table[minor]; minor++);
- if (minor == HIDDEV_MINORS) {
- printk(KERN_ERR "hiddev: no more free hiddev devicesn");
- return -1;
- }
- if (!(hiddev = kmalloc(sizeof(struct hiddev), GFP_KERNEL)))
- return -1;
- memset(hiddev, 0, sizeof(struct hiddev));
- init_waitqueue_head(&hiddev->wait);
- hiddev->minor = minor;
- hiddev_table[minor] = hiddev;
- hiddev->hid = hid;
- hiddev->exist = 1;
- sprintf(devfs_name, "hiddev%d", minor);
- hiddev->devfs = devfs_register(hiddev_devfs_handle, devfs_name,
- DEVFS_FL_DEFAULT, USB_MAJOR,
- minor + HIDDEV_MINOR_BASE,
- S_IFCHR | S_IRUGO | S_IWUSR,
- &hiddev_fops, NULL);
- hid->minor = minor;
- hid->hiddev = hiddev;
- return 0;
- }
- /*
- * This is where hid.c calls us to disconnect a hiddev device from the
- * corresponding hid device (usually because the usb device has disconnected)
- */
- void hiddev_disconnect(struct hid_device *hid)
- {
- struct hiddev *hiddev = hid->hiddev;
- hiddev->exist = 0;
- if (hiddev->open) {
- hid_close(hiddev->hid);
- wake_up_interruptible(&hiddev->wait);
- } else {
- hiddev_cleanup(hiddev);
- }
- }
- /* Currently this driver is a USB driver. It's not a conventional one in
- * the sense that it doesn't probe at the USB level. Instead it waits to
- * be connected by HID through the hiddev_connect / hiddev_disconnect
- * routines. The reason to register as a USB device is to gain part of the
- * minor number space from the USB major.
- *
- * In theory, should the HID code be generalized to more than one physical
- * medium (say, IEEE 1384), this driver will probably need to register its
- * own major number, and in doing so, no longer need to register with USB.
- * At that point the probe routine and hiddev_driver struct below will no
- * longer be useful.
- */
- /* We never attach in this manner, and rely on HID to connect us. This
- * is why there is no disconnect routine defined in the usb_driver either.
- */
- static void *hiddev_usbd_probe(struct usb_device *dev, unsigned int ifnum,
- const struct usb_device_id *hiddev_info)
- {
- return NULL;
- }
- static /* const */ struct usb_driver hiddev_driver = {
- name: "hiddev",
- probe: hiddev_usbd_probe,
- fops: &hiddev_fops,
- minor: HIDDEV_MINOR_BASE
- };
- int __init hiddev_init(void)
- {
- hiddev_devfs_handle =
- devfs_mk_dir(devfs_find_handle(NULL, "usb", 0, 0, 0, 0), "hid", NULL);
- usb_register(&hiddev_driver);
- return 0;
- }
- void __exit hiddev_exit(void)
- {
- devfs_unregister(hiddev_devfs_handle);
- usb_deregister(&hiddev_driver);
- }