evdev.c
/*
* Event char devices, giving access to raw input device events.
*
* Copyright (c) 1999-2002 Vojtech Pavlik
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#define EVDEV_MINOR_BASE 64
#define EVDEV_MINORS 32
#define EVDEV_BUFFER_SIZE 64
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/major.h>
#include <linux/smp_lock.h>
#include <linux/device.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/compat.h>
struct evdev {
int exist;
int open;
int minor;
char name[16];
struct input_handle handle;
wait_queue_head_t wait;
struct evdev_list *grab;
struct list_head list;
};
struct evdev_list {
struct input_event buffer[EVDEV_BUFFER_SIZE];
int head;
int tail;
struct fasync_struct *fasync;
struct evdev *evdev;
struct list_head node;
};
static struct evdev *evdev_table[EVDEV_MINORS];
static void evdev_event(struct input_handle *handle, unsigned int type, unsigned int code, int value)
{
struct evdev *evdev = handle->private;
struct evdev_list *list;
if (evdev->grab) {
list = evdev->grab;
do_gettimeofday(&list->buffer[list->head].time);
list->buffer[list->head].type = type;
list->buffer[list->head].code = code;
list->buffer[list->head].value = value;
list->head = (list->head + 1) & (EVDEV_BUFFER_SIZE - 1);
kill_fasync(&list->fasync, SIGIO, POLL_IN);
} else
list_for_each_entry(list, &evdev->list, node) {
do_gettimeofday(&list->buffer[list->head].time);
list->buffer[list->head].type = type;
list->buffer[list->head].code = code;
list->buffer[list->head].value = value;
list->head = (list->head + 1) & (EVDEV_BUFFER_SIZE - 1);
kill_fasync(&list->fasync, SIGIO, POLL_IN);
}
wake_up_interruptible(&evdev->wait);
}
static int evdev_fasync(int fd, struct file *file, int on)
{
int retval;
struct evdev_list *list = file->private_data;
retval = fasync_helper(fd, file, on, &list->fasync);
return retval < 0 ? retval : 0;
}
static int evdev_flush(struct file * file)
{
struct evdev_list *list = file->private_data;
if (!list->evdev->exist) return -ENODEV;
return input_flush_device(&list->evdev->handle, file);
}
static void evdev_free(struct evdev *evdev)
{
evdev_table[evdev->minor] = NULL;
kfree(evdev);
}
static int evdev_release(struct inode * inode, struct file * file)
{
struct evdev_list *list = file->private_data;
if (list->evdev->grab == list) {
input_release_device(&list->evdev->handle);
list->evdev->grab = NULL;
}
evdev_fasync(-1, file, 0);
list_del(&list->node);
if (!--list->evdev->open) {
if (list->evdev->exist)
input_close_device(&list->evdev->handle);
else
evdev_free(list->evdev);
}
kfree(list);
return 0;
}
static int evdev_open(struct inode * inode, struct file * file)
{
struct evdev_list *list;
int i = iminor(inode) - EVDEV_MINOR_BASE;
int accept_err;
if (i >= EVDEV_MINORS || !evdev_table[i] || !evdev_table[i]->exist)
return -ENODEV;
if ((accept_err = input_accept_process(&(evdev_table[i]->handle), file)))
return accept_err;
if (!(list = kmalloc(sizeof(struct evdev_list), GFP_KERNEL)))
return -ENOMEM;
memset(list, 0, sizeof(struct evdev_list));
list->evdev = evdev_table[i];
list_add_tail(&list->node, &evdev_table[i]->list);
file->private_data = list;
if (!list->evdev->open++)
if (list->evdev->exist)
input_open_device(&list->evdev->handle);
return 0;
}
#ifdef CONFIG_COMPAT
struct input_event_compat {
struct compat_timeval time;
__u16 type;
__u16 code;
__s32 value;
};
#ifdef CONFIG_X86_64
# define COMPAT_TEST test_thread_flag(TIF_IA32)
#elif defined(CONFIG_IA64)
# define COMPAT_TEST IS_IA32_PROCESS(ia64_task_regs(current))
#elif defined(CONFIG_ARCH_S390)
# define COMPAT_TEST test_thread_flag(TIF_31BIT)
#else
# define COMPAT_TEST test_thread_flag(TIF_32BIT)
#endif
static ssize_t evdev_write_compat(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
{
struct evdev_list *list = file->private_data;
struct input_event_compat event;
int retval = 0;
while (retval < count) {
if (copy_from_user(&event, buffer + retval, sizeof(struct input_event_compat)))
return -EFAULT;
input_event(list->evdev->handle.dev, event.type, event.code, event.value);
retval += sizeof(struct input_event_compat);
}
return retval;
}
#endif
static ssize_t evdev_write(struct file * file, const char __user * buffer, size_t count, loff_t *ppos)
{
struct evdev_list *list = file->private_data;
struct input_event event;
int retval = 0;
if (!list->evdev->exist) return -ENODEV;
#ifdef CONFIG_COMPAT
if (COMPAT_TEST)
return evdev_write_compat(file, buffer, count, ppos);
#endif
while (retval < count) {
if (copy_from_user(&event, buffer + retval, sizeof(struct input_event)))
return -EFAULT;
input_event(list->evdev->handle.dev, event.type, event.code, event.value);
retval += sizeof(struct input_event);
}
return retval;
}
#ifdef CONFIG_COMPAT
static ssize_t evdev_read_compat(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
{
struct evdev_list *list = file->private_data;
int retval;
if (count < sizeof(struct input_event_compat))
return -EINVAL;
if (list->head == list->tail && list->evdev->exist && (file->f_flags & O_NONBLOCK))
return -EAGAIN;
retval = wait_event_interruptible(list->evdev->wait,
list->head != list->tail || (!list->evdev->exist));
if (retval)
return retval;
if (!list->evdev->exist)
return -ENODEV;
while (list->head != list->tail && retval + sizeof(struct input_event_compat) <= count) {
struct input_event *event = (struct input_event *) list->buffer + list->tail;
struct input_event_compat event_compat;
event_compat.time.tv_sec = event->time.tv_sec;
event_compat.time.tv_usec = event->time.tv_usec;
event_compat.type = event->type;
event_compat.code = event->code;
event_compat.value = event->value;
if (copy_to_user(buffer + retval, &event_compat,
sizeof(struct input_event_compat))) return -EFAULT;
list->tail = (list->tail + 1) & (EVDEV_BUFFER_SIZE - 1);
retval += sizeof(struct input_event_compat);
}
return retval;
}
#endif
static ssize_t evdev_read(struct file * file, char __user * buffer, size_t count, loff_t *ppos)
{
struct evdev_list *list = file->private_data;
int retval;
#ifdef CONFIG_COMPAT
if (COMPAT_TEST)
return evdev_read_compat(file, buffer, count, ppos);
#endif
if (count < sizeof(struct input_event))
return -EINVAL;
if (list->head == list->tail && list->evdev->exist && (file->f_flags & O_NONBLOCK))
return -EAGAIN;
retval = wait_event_interruptible(list->evdev->wait,
list->head != list->tail || (!list->evdev->exist));
if (retval)
return retval;
if (!list->evdev->exist)
return -ENODEV;
while (list->head != list->tail && retval + sizeof(struct input_event) <= count) {
if (copy_to_user(buffer + retval, list->buffer + list->tail,
sizeof(struct input_event))) return -EFAULT;
list->tail = (list->tail + 1) & (EVDEV_BUFFER_SIZE - 1);
retval += sizeof(struct input_event);
}
return retval;
}
/* No kernel lock - fine */
static unsigned int evdev_poll(struct file *file, poll_table *wait)
{
struct evdev_list *list = file->private_data;
poll_wait(file, &list->evdev->wait, wait);
return ((list->head == list->tail) ? 0 : (POLLIN | POLLRDNORM)) |
(list->evdev->exist ? 0 : (POLLHUP | POLLERR));
}
static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct evdev_list *list = file->private_data;
struct evdev *evdev = list->evdev;
struct input_dev *dev = evdev->handle.dev;
struct input_absinfo abs;
void __user *p = (void __user *)arg;
int __user *ip = (int __user *)arg;
int i, t, u, v;
if (!evdev->exist) return -ENODEV;
switch (cmd) {
case EVIOCGVERSION:
return put_user(EV_VERSION, ip);
case EVIOCGID:
return copy_to_user(p, &dev->id, sizeof(struct input_id)) ? -EFAULT : 0;
case EVIOCGKEYCODE:
if (get_user(t, ip)) return -EFAULT;
if (t < 0 || t >= dev->keycodemax || !dev->keycodesize) return -EINVAL;
if (put_user(INPUT_KEYCODE(dev, t), ip + 1)) return -EFAULT;
return 0;
case EVIOCSKEYCODE:
if (get_user(t, ip)) return -EFAULT;
if (t < 0 || t >= dev->keycodemax || !dev->keycodesize) return -EINVAL;
if (get_user(v, ip + 1)) return -EFAULT;
if (v < 0 || v > KEY_MAX) return -EINVAL;
if (v >> (dev->keycodesize * 8)) return -EINVAL;
u = SET_INPUT_KEYCODE(dev, t, v);
clear_bit(u, dev->keybit);
set_bit(v, dev->keybit);
for (i = 0; i < dev->keycodemax; i++)
if (INPUT_KEYCODE(dev,i) == u)
set_bit(u, dev->keybit);
return 0;
case EVIOCSFF:
if (dev->upload_effect) {
struct ff_effect effect;
int err;
if (copy_from_user(&effect, p, sizeof(effect)))
return -EFAULT;
err = dev->upload_effect(dev, &effect);
if (put_user(effect.id, &(((struct ff_effect __user *)arg)->id)))
return -EFAULT;
return err;
}
else return -ENOSYS;
case EVIOCRMFF:
if (dev->erase_effect) {
return dev->erase_effect(dev, (int)arg);
}
else return -ENOSYS;
case EVIOCGEFFECTS:
if (put_user(dev->ff_effects_max, ip))
return -EFAULT;
return 0;
case EVIOCGRAB:
if (arg) {
if (evdev->grab)
return -EBUSY;
if (input_grab_device(&evdev->handle))
return -EBUSY;
evdev->grab = list;
return 0;
} else {
if (evdev->grab != list)
return -EINVAL;
input_release_device(&evdev->handle);
evdev->grab = NULL;
return 0;
}
default:
if (_IOC_TYPE(cmd) != 'E')
return -EINVAL;
if (_IOC_DIR(cmd) == _IOC_READ) {
if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0,0))) {
long *bits;
int len;
switch (_IOC_NR(cmd) & EV_MAX) {
case 0: bits = dev->evbit; len = EV_MAX; break;
case EV_KEY: bits = dev->keybit; len = KEY_MAX; break;
case EV_REL: bits = dev->relbit; len = REL_MAX; break;
case EV_ABS: bits = dev->absbit; len = ABS_MAX; break;
case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break;
case EV_LED: bits = dev->ledbit; len = LED_MAX; break;
case EV_SND: bits = dev->sndbit; len = SND_MAX; break;
case EV_FF: bits = dev->ffbit; len = FF_MAX; break;
default: return -EINVAL;
}
len = NBITS(len) * sizeof(long);
if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
return copy_to_user(p, bits, len) ? -EFAULT : len;
}
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0))) {
int len;
len = NBITS(KEY_MAX) * sizeof(long);
if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
return copy_to_user(p, dev->key, len) ? -EFAULT : len;
}
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0))) {
int len;
len = NBITS(LED_MAX) * sizeof(long);
if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
return copy_to_user(p, dev->led, len) ? -EFAULT : len;
}
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0))) {
int len;
len = NBITS(SND_MAX) * sizeof(long);
if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
return copy_to_user(p, dev->snd, len) ? -EFAULT : len;
}
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0))) {
int len;
if (!dev->name) return -ENOENT;
len = strlen(dev->name) + 1;
if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
return copy_to_user(p, dev->name, len) ? -EFAULT : len;
}
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0))) {
int len;
if (!dev->phys) return -ENOENT;
len = strlen(dev->phys) + 1;
if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
return copy_to_user(p, dev->phys, len) ? -EFAULT : len;
}
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0))) {
int len;
if (!dev->uniq) return -ENOENT;
len = strlen(dev->uniq) + 1;
if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
return copy_to_user(p, dev->uniq, len) ? -EFAULT : len;
}
if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
int t = _IOC_NR(cmd) & ABS_MAX;
abs.value = dev->abs[t];
abs.minimum = dev->absmin[t];
abs.maximum = dev->absmax[t];
abs.fuzz = dev->absfuzz[t];
abs.flat = dev->absflat[t];
if (copy_to_user(p, &abs, sizeof(struct input_absinfo)))
return -EFAULT;
return 0;
}
}
if (_IOC_DIR(cmd) == _IOC_WRITE) {
if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
int t = _IOC_NR(cmd) & ABS_MAX;
if (copy_from_user(&abs, p, sizeof(struct input_absinfo)))
return -EFAULT;
dev->abs[t] = abs.value;
dev->absmin[t] = abs.minimum;
dev->absmax[t] = abs.maximum;
dev->absfuzz[t] = abs.fuzz;
dev->absflat[t] = abs.flat;
return 0;
}
}
}
return -EINVAL;
}
#ifdef CONFIG_COMPAT
#define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
#define NBITS_COMPAT(x) ((((x)-1)/BITS_PER_LONG_COMPAT)+1)
#define OFF_COMPAT(x) ((x)%BITS_PER_LONG_COMPAT)
#define BIT_COMPAT(x) (1UL<<OFF_COMPAT(x))
#define LONG_COMPAT(x) ((x)/BITS_PER_LONG_COMPAT)
#define test_bit_compat(bit, array) ((array[LONG_COMPAT(bit)] >> OFF_COMPAT(bit)) & 1)
#ifdef __BIG_ENDIAN
#define bit_to_user(bit, max) \
do { \
int i; \
int len = NBITS_COMPAT((max)) * sizeof(compat_long_t); \
if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd); \
for (i = 0; i < len / sizeof(compat_long_t); i++) \
if (copy_to_user((compat_long_t*) p + i, \
(compat_long_t*) (bit) + i + 1 - ((i % 2) << 1), \
sizeof(compat_long_t))) \
return -EFAULT; \
return len; \
} while (0)
#else
#define bit_to_user(bit, max) \
do { \
int len = NBITS_COMPAT((max)) * sizeof(compat_long_t); \
if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd); \
return copy_to_user(p, (bit), len) ? -EFAULT : len; \
} while (0)
#endif
static long evdev_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
{
struct evdev_list *list = file->private_data;
struct evdev *evdev = list->evdev;
struct input_dev *dev = evdev->handle.dev;
struct input_absinfo abs;
void __user *p = compat_ptr(arg);
if (!evdev->exist) return -ENODEV;
switch (cmd) {
case EVIOCGVERSION:
case EVIOCGID:
case EVIOCGKEYCODE:
case EVIOCSKEYCODE:
case EVIOCSFF:
case EVIOCRMFF:
case EVIOCGEFFECTS:
case EVIOCGRAB:
return evdev_ioctl(file, cmd, (unsigned long) p);
default:
if (_IOC_TYPE(cmd) != 'E')
return -EINVAL;
if (_IOC_DIR(cmd) == _IOC_READ) {
if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0,0))) {
long *bits;
int max;
switch (_IOC_NR(cmd) & EV_MAX) {
case 0: bits = dev->evbit; max = EV_MAX; break;
case EV_KEY: bits = dev->keybit; max = KEY_MAX; break;
case EV_REL: bits = dev->relbit; max = REL_MAX; break;
case EV_ABS: bits = dev->absbit; max = ABS_MAX; break;
case EV_MSC: bits = dev->mscbit; max = MSC_MAX; break;
case EV_LED: bits = dev->ledbit; max = LED_MAX; break;
case EV_SND: bits = dev->sndbit; max = SND_MAX; break;
case EV_FF: bits = dev->ffbit; max = FF_MAX; break;
default: return -EINVAL;
}
bit_to_user(bits, max);
}
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
bit_to_user(dev->key, KEY_MAX);
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
bit_to_user(dev->led, LED_MAX);
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
bit_to_user(dev->snd, SND_MAX);
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0))) {
int len;
if (!dev->name) return -ENOENT;
len = strlen(dev->name) + 1;
if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
return copy_to_user(p, dev->name, len) ? -EFAULT : len;
}
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0))) {
int len;
if (!dev->phys) return -ENOENT;
len = strlen(dev->phys) + 1;
if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
return copy_to_user(p, dev->phys, len) ? -EFAULT : len;
}
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0))) {
int len;
if (!dev->uniq) return -ENOENT;
len = strlen(dev->uniq) + 1;
if (len > _IOC_SIZE(cmd)) len = _IOC_SIZE(cmd);
return copy_to_user(p, dev->uniq, len) ? -EFAULT : len;
}
if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
int t = _IOC_NR(cmd) & ABS_MAX;
abs.value = dev->abs[t];
abs.minimum = dev->absmin[t];
abs.maximum = dev->absmax[t];
abs.fuzz = dev->absfuzz[t];
abs.flat = dev->absflat[t];
if (copy_to_user(p, &abs, sizeof(struct input_absinfo)))
return -EFAULT;
return 0;
}
}
if (_IOC_DIR(cmd) == _IOC_WRITE) {
if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCSABS(0))) {
int t = _IOC_NR(cmd) & ABS_MAX;
if (copy_from_user(&abs, p, sizeof(struct input_absinfo)))
return -EFAULT;
dev->abs[t] = abs.value;
dev->absmin[t] = abs.minimum;
dev->absmax[t] = abs.maximum;
dev->absfuzz[t] = abs.fuzz;
dev->absflat[t] = abs.flat;
return 0;
}
}
}
return -EINVAL;
}
#endif
static struct file_operations evdev_fops = {
.owner = THIS_MODULE,
.read = evdev_read,
.write = evdev_write,
.poll = evdev_poll,
.open = evdev_open,
.release = evdev_release,
.unlocked_ioctl = evdev_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = evdev_ioctl_compat,
#endif
.fasync = evdev_fasync,
.flush = evdev_flush
};
static struct input_handle *evdev_connect(struct input_handler *handler, struct input_dev *dev, struct input_device_id *id)
{
struct evdev *evdev;
int minor;
for (minor = 0; minor < EVDEV_MINORS && evdev_table[minor]; minor++);
if (minor == EVDEV_MINORS) {
printk(KERN_ERR "evdev: no more free evdev devices\n");
return NULL;
}
if (!(evdev = kmalloc(sizeof(struct evdev), GFP_KERNEL)))
return NULL;
memset(evdev, 0, sizeof(struct evdev));
INIT_LIST_HEAD(&evdev->list);
init_waitqueue_head(&evdev->wait);
evdev->exist = 1;
evdev->minor = minor;
evdev->handle.dev = dev;
evdev->handle.name = evdev->name;
evdev->handle.handler = handler;
evdev->handle.private = evdev;
sprintf(evdev->name, "event%d", minor);
evdev_table[minor] = evdev;
devfs_mk_cdev(MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor),
S_IFCHR|S_IRUGO|S_IWUSR, "input/event%d", minor);
class_device_create(input_class,
MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor),
dev->dev, "event%d", minor);
return &evdev->handle;
}
static void evdev_disconnect(struct input_handle *handle)
{
struct evdev *evdev = handle->private;
struct evdev_list *list;
class_device_destroy(input_class,
MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + evdev->minor));
devfs_remove("input/event%d", evdev->minor);
evdev->exist = 0;
if (evdev->open) {
input_close_device(handle);
wake_up_interruptible(&evdev->wait);
list_for_each_entry(list, &evdev->list, node)
kill_fasync(&list->fasync, SIGIO, POLL_HUP);
} else
evdev_free(evdev);
}
static struct input_device_id evdev_ids[] = {
{ .driver_info = 1 }, /* Matches all devices */
{ }, /* Terminating zero entry */
};
MODULE_DEVICE_TABLE(input, evdev_ids);
static struct input_handler evdev_handler = {
.event = evdev_event,
.connect = evdev_connect,
.disconnect = evdev_disconnect,
.fops = &evdev_fops,
.minor = EVDEV_MINOR_BASE,
.name = "evdev",
.id_table = evdev_ids,
};
static int __init evdev_init(void)
{
input_register_handler(&evdev_handler);
return 0;
}
static void __exit evdev_exit(void)
{
input_unregister_handler(&evdev_handler);
}
module_init(evdev_init);
module_exit(evdev_exit);
MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("Input driver event char devices");
MODULE_LICENSE("GPL");