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/device.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_client *grab;
struct list_head client_list;
struct device dev;
};
struct evdev_client {
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_client *client;
if (evdev->grab) {
client = evdev->grab;
do_gettimeofday(&client->buffer[client->head].time);
client->buffer[client->head].type = type;
client->buffer[client->head].code = code;
client->buffer[client->head].value = value;
client->head = (client->head + 1) & (EVDEV_BUFFER_SIZE - 1);
kill_fasync(&client->fasync, SIGIO, POLL_IN);
} else
list_for_each_entry(client, &evdev->client_list, node) {
do_gettimeofday(&client->buffer[client->head].time);
client->buffer[client->head].type = type;
client->buffer[client->head].code = code;
client->buffer[client->head].value = value;
client->head = (client->head + 1) & (EVDEV_BUFFER_SIZE - 1);
kill_fasync(&client->fasync, SIGIO, POLL_IN);
}
wake_up_interruptible(&evdev->wait);
}
static int evdev_fasync(int fd, struct file *file, int on)
{
struct evdev_client *client = file->private_data;
int retval;
retval = fasync_helper(fd, file, on, &client->fasync);
return retval < 0 ? retval : 0;
}
static int evdev_flush(struct file *file, fl_owner_t id)
{
struct evdev_client *client = file->private_data;
struct evdev *evdev = client->evdev;
if (!evdev->exist)
return -ENODEV;
return input_flush_device(&evdev->handle, file);
}
static void evdev_free(struct device *dev)
{
struct evdev *evdev = container_of(dev, struct evdev, dev);
evdev_table[evdev->minor] = NULL;
kfree(evdev);
}
static int evdev_release(struct inode *inode, struct file *file)
{
struct evdev_client *client = file->private_data;
struct evdev *evdev = client->evdev;
if (evdev->grab == client) {
input_release_device(&evdev->handle);
evdev->grab = NULL;
}
evdev_fasync(-1, file, 0);
list_del(&client->node);
kfree(client);
if (!--evdev->open && evdev->exist)
input_close_device(&evdev->handle);
put_device(&evdev->dev);
return 0;
}
static int evdev_open(struct inode *inode, struct file *file)
{
struct evdev_client *client;
struct evdev *evdev;
int i = iminor(inode) - EVDEV_MINOR_BASE;
int error;
if (i >= EVDEV_MINORS)
return -ENODEV;
evdev = evdev_table[i];
if (!evdev || !evdev->exist)
return -ENODEV;
get_device(&evdev->dev);
client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL);
if (!client) {
error = -ENOMEM;
goto err_put_evdev;
}
client->evdev = evdev;
list_add_tail(&client->node, &evdev->client_list);
if (!evdev->open++ && evdev->exist) {
error = input_open_device(&evdev->handle);
if (error)
goto err_free_client;
}
file->private_data = client;
return 0;
err_free_client:
list_del(&client->node);
kfree(client);
err_put_evdev:
put_device(&evdev->dev);
return error;
}
#ifdef CONFIG_COMPAT
struct input_event_compat {
struct compat_timeval time;
__u16 type;
__u16 code;
__s32 value;
};
/* Note to the author of this code: did it ever occur to
you why the ifdefs are needed? Think about it again. -AK */
#ifdef CONFIG_X86_64
# define COMPAT_TEST is_compat_task()
#elif defined(CONFIG_IA64)
# define COMPAT_TEST IS_IA32_PROCESS(task_pt_regs(current))
#elif defined(CONFIG_S390)
# define COMPAT_TEST test_thread_flag(TIF_31BIT)
#elif defined(CONFIG_MIPS)
# define COMPAT_TEST test_thread_flag(TIF_32BIT_ADDR)
#else
# define COMPAT_TEST test_thread_flag(TIF_32BIT)
#endif
static inline size_t evdev_event_size(void)
{
return COMPAT_TEST ?
sizeof(struct input_event_compat) : sizeof(struct input_event);
}
static int evdev_event_from_user(const char __user *buffer, struct input_event *event)
{
if (COMPAT_TEST) {
struct input_event_compat compat_event;
if (copy_from_user(&compat_event, buffer, sizeof(struct input_event_compat)))
return -EFAULT;
event->time.tv_sec = compat_event.time.tv_sec;
event->time.tv_usec = compat_event.time.tv_usec;
event->type = compat_event.type;
event->code = compat_event.code;
event->value = compat_event.value;
} else {
if (copy_from_user(event, buffer, sizeof(struct input_event)))
return -EFAULT;
}
return 0;
}
static int evdev_event_to_user(char __user *buffer, const struct input_event *event)
{
if (COMPAT_TEST) {
struct input_event_compat compat_event;
compat_event.time.tv_sec = event->time.tv_sec;
compat_event.time.tv_usec = event->time.tv_usec;
compat_event.type = event->type;
compat_event.code = event->code;
compat_event.value = event->value;
if (copy_to_user(buffer, &compat_event, sizeof(struct input_event_compat)))
return -EFAULT;
} else {
if (copy_to_user(buffer, event, sizeof(struct input_event)))
return -EFAULT;
}
return 0;
}
#else
static inline size_t evdev_event_size(void)
{
return sizeof(struct input_event);
}
static int evdev_event_from_user(const char __user *buffer, struct input_event *event)
{
if (copy_from_user(event, buffer, sizeof(struct input_event)))
return -EFAULT;
return 0;
}
static int evdev_event_to_user(char __user *buffer, const struct input_event *event)
{
if (copy_to_user(buffer, event, sizeof(struct input_event)))
return -EFAULT;
return 0;
}
#endif /* CONFIG_COMPAT */
static ssize_t evdev_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
{
struct evdev_client *client = file->private_data;
struct evdev *evdev = client->evdev;
struct input_event event;
int retval = 0;
if (!evdev->exist)
return -ENODEV;
while (retval < count) {
if (evdev_event_from_user(buffer + retval, &event))
return -EFAULT;
input_inject_event(&evdev->handle, event.type, event.code, event.value);
retval += evdev_event_size();
}
return retval;
}
static ssize_t evdev_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
{
struct evdev_client *client = file->private_data;
struct evdev *evdev = client->evdev;
int retval;
if (count < evdev_event_size())
return -EINVAL;
if (client->head == client->tail && evdev->exist && (file->f_flags & O_NONBLOCK))
return -EAGAIN;
retval = wait_event_interruptible(evdev->wait,
client->head != client->tail || !evdev->exist);
if (retval)
return retval;
if (!evdev->exist)
return -ENODEV;
while (client->head != client->tail && retval + evdev_event_size() <= count) {
struct input_event *event = (struct input_event *) client->buffer + client->tail;
if (evdev_event_to_user(buffer + retval, event))
return -EFAULT;
client->tail = (client->tail + 1) & (EVDEV_BUFFER_SIZE - 1);
retval += evdev_event_size();
}
return retval;
}
/* No kernel lock - fine */
static unsigned int evdev_poll(struct file *file, poll_table *wait)
{
struct evdev_client *client = file->private_data;
struct evdev *evdev = client->evdev;
poll_wait(file, &evdev->wait, wait);
return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
(evdev->exist ? 0 : (POLLHUP | POLLERR));
}
#ifdef CONFIG_COMPAT
#define BITS_PER_LONG_COMPAT (sizeof(compat_long_t) * 8)
#define NBITS_COMPAT(x) ((((x) - 1) / BITS_PER_LONG_COMPAT) + 1)
#ifdef __BIG_ENDIAN
static int bits_to_user(unsigned long *bits, unsigned int maxbit,
unsigned int maxlen, void __user *p, int compat)
{
int len, i;
if (compat) {
len = NBITS_COMPAT(maxbit) * sizeof(compat_long_t);
if (len > maxlen)
len = maxlen;
for (i = 0; i < len / sizeof(compat_long_t); i++)
if (copy_to_user((compat_long_t __user *) p + i,
(compat_long_t *) bits +
i + 1 - ((i % 2) << 1),
sizeof(compat_long_t)))
return -EFAULT;
} else {
len = NBITS(maxbit) * sizeof(long);
if (len > maxlen)
len = maxlen;
if (copy_to_user(p, bits, len))
return -EFAULT;
}
return len;
}
#else
static int bits_to_user(unsigned long *bits, unsigned int maxbit,
unsigned int maxlen, void __user *p, int compat)
{
int len = compat ?
NBITS_COMPAT(maxbit) * sizeof(compat_long_t) :
NBITS(maxbit) * sizeof(long);
if (len > maxlen)
len = maxlen;
return copy_to_user(p, bits, len) ? -EFAULT : len;
}
#endif /* __BIG_ENDIAN */
#else
static int bits_to_user(unsigned long *bits, unsigned int maxbit,
unsigned int maxlen, void __user *p, int compat)
{
int len = NBITS(maxbit) * sizeof(long);
if (len > maxlen)
len = maxlen;
return copy_to_user(p, bits, len) ? -EFAULT : len;
}
#endif /* CONFIG_COMPAT */
static int str_to_user(const char *str, unsigned int maxlen, void __user *p)
{
int len;
if (!str)
return -ENOENT;
len = strlen(str) + 1;
if (len > maxlen)
len = maxlen;
return copy_to_user(p, str, len) ? -EFAULT : len;
}
static long evdev_ioctl_handler(struct file *file, unsigned int cmd,
void __user *p, int compat_mode)
{
struct evdev_client *client = file->private_data;
struct evdev *evdev = client->evdev;
struct input_dev *dev = evdev->handle.dev;
struct input_absinfo abs;
struct ff_effect effect;
int __user *ip = (int __user *)p;
int i, t, u, v;
int error;
if (!evdev->exist)
return -ENODEV;
switch (cmd) {
case EVIOCGVERSION:
return put_user(EV_VERSION, ip);
case EVIOCGID:
if (copy_to_user(p, &dev->id, sizeof(struct input_id)))
return -EFAULT;
return 0;
case EVIOCGREP:
if (!test_bit(EV_REP, dev->evbit))
return -ENOSYS;
if (put_user(dev->rep[REP_DELAY], ip))
return -EFAULT;
if (put_user(dev->rep[REP_PERIOD], ip + 1))
return -EFAULT;
return 0;
case EVIOCSREP:
if (!test_bit(EV_REP, dev->evbit))
return -ENOSYS;
if (get_user(u, ip))
return -EFAULT;
if (get_user(v, ip + 1))
return -EFAULT;
input_inject_event(&evdev->handle, EV_REP, REP_DELAY, u);
input_inject_event(&evdev->handle, EV_REP, REP_PERIOD, v);
return 0;
case EVIOCGKEYCODE:
if (get_user(t, ip))
return -EFAULT;
error = dev->getkeycode(dev, t, &v);
if (error)
return error;
if (put_user(v, ip + 1))
return -EFAULT;
return 0;
case EVIOCSKEYCODE:
if (get_user(t, ip) || get_user(v, ip + 1))
return -EFAULT;
return dev->setkeycode(dev, t, v);
case EVIOCSFF:
if (copy_from_user(&effect, p, sizeof(effect)))
return -EFAULT;
error = input_ff_upload(dev, &effect, file);
if (put_user(effect.id, &(((struct ff_effect __user *)p)->id)))
return -EFAULT;
return error;
case EVIOCRMFF:
return input_ff_erase(dev, (int)(unsigned long) p, file);
case EVIOCGEFFECTS:
i = test_bit(EV_FF, dev->evbit) ? dev->ff->max_effects : 0;
if (put_user(i, ip))
return -EFAULT;
return 0;
case EVIOCGRAB:
if (p) {
if (evdev->grab)
return -EBUSY;
if (input_grab_device(&evdev->handle))
return -EBUSY;
evdev->grab = client;
return 0;
} else {
if (evdev->grab != client)
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))) {
unsigned 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;
case EV_SW: bits = dev->swbit; len = SW_MAX; break;
default: return -EINVAL;
}
return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode);
}
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0)))
return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd),
p, compat_mode);
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGLED(0)))
return bits_to_user(dev->led, LED_MAX, _IOC_SIZE(cmd),
p, compat_mode);
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSND(0)))
return bits_to_user(dev->snd, SND_MAX, _IOC_SIZE(cmd),
p, compat_mode);
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGSW(0)))
return bits_to_user(dev->sw, SW_MAX, _IOC_SIZE(cmd),
p, compat_mode);
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGNAME(0)))
return str_to_user(dev->name, _IOC_SIZE(cmd), p);
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGPHYS(0)))
return str_to_user(dev->phys, _IOC_SIZE(cmd), p);
if (_IOC_NR(cmd) == _IOC_NR(EVIOCGUNIQ(0)))
return str_to_user(dev->uniq, _IOC_SIZE(cmd), p);
if ((_IOC_NR(cmd) & ~ABS_MAX) == _IOC_NR(EVIOCGABS(0))) {
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))) {
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;
}
static long evdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
return evdev_ioctl_handler(file, cmd, (void __user *)arg, 0);
}
#ifdef CONFIG_COMPAT
static long evdev_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
{
return evdev_ioctl_handler(file, cmd, compat_ptr(arg), 1);
}
#endif
static const 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 int evdev_connect(struct input_handler *handler, struct input_dev *dev,
const struct input_device_id *id)
{
struct evdev *evdev;
int minor;
int error;
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 -ENFILE;
}
evdev = kzalloc(sizeof(struct evdev), GFP_KERNEL);
if (!evdev)
return -ENOMEM;
INIT_LIST_HEAD(&evdev->client_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;
snprintf(evdev->name, sizeof(evdev->name), "event%d", minor);
snprintf(evdev->dev.bus_id, sizeof(evdev->dev.bus_id),
"event%d", minor);
evdev->dev.class = &input_class;
evdev->dev.parent = &dev->dev;
evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor);
evdev->dev.release = evdev_free;
device_initialize(&evdev->dev);
evdev_table[minor] = evdev;
error = device_add(&evdev->dev);
if (error)
goto err_free_evdev;
error = input_register_handle(&evdev->handle);
if (error)
goto err_delete_evdev;
return 0;
err_delete_evdev:
device_del(&evdev->dev);
err_free_evdev:
put_device(&evdev->dev);
return error;
}
static void evdev_disconnect(struct input_handle *handle)
{
struct evdev *evdev = handle->private;
struct evdev_client *client;
input_unregister_handle(handle);
device_del(&evdev->dev);
evdev->exist = 0;
if (evdev->open) {
input_flush_device(handle, NULL);
input_close_device(handle);
list_for_each_entry(client, &evdev->client_list, node)
kill_fasync(&client->fasync, SIGIO, POLL_HUP);
wake_up_interruptible(&evdev->wait);
}
put_device(&evdev->dev);
}
static const 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)
{
return input_register_handler(&evdev_handler);
}
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");