diff options
Diffstat (limited to 'drivers/input/evdev.c')
-rw-r--r-- | drivers/input/evdev.c | 1075 |
1 files changed, 1075 insertions, 0 deletions
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c new file mode 100644 index 0000000..1070db3 --- /dev/null +++ b/drivers/input/evdev.c @@ -0,0 +1,1075 @@ +/* + * 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; + spinlock_t client_lock; /* protects client_list */ + struct mutex mutex; + struct device dev; +}; + +struct evdev_client { + struct input_event buffer[EVDEV_BUFFER_SIZE]; + int head; + int tail; + spinlock_t buffer_lock; /* protects access to buffer, head and tail */ + struct fasync_struct *fasync; + struct evdev *evdev; + struct list_head node; +}; + +static struct evdev *evdev_table[EVDEV_MINORS]; +static DEFINE_MUTEX(evdev_table_mutex); + +static void evdev_pass_event(struct evdev_client *client, + struct input_event *event) +{ + /* + * Interrupts are disabled, just acquire the lock + */ + spin_lock(&client->buffer_lock); + client->buffer[client->head++] = *event; + client->head &= EVDEV_BUFFER_SIZE - 1; + spin_unlock(&client->buffer_lock); + + kill_fasync(&client->fasync, SIGIO, POLL_IN); +} + +/* + * Pass incoming event to all connected clients. + */ +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; + struct input_event event; + + do_gettimeofday(&event.time); + event.type = type; + event.code = code; + event.value = value; + + rcu_read_lock(); + + client = rcu_dereference(evdev->grab); + if (client) + evdev_pass_event(client, &event); + else + list_for_each_entry_rcu(client, &evdev->client_list, node) + evdev_pass_event(client, &event); + + rcu_read_unlock(); + + 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; + int retval; + + retval = mutex_lock_interruptible(&evdev->mutex); + if (retval) + return retval; + + if (!evdev->exist) + retval = -ENODEV; + else + retval = input_flush_device(&evdev->handle, file); + + mutex_unlock(&evdev->mutex); + return retval; +} + +static void evdev_free(struct device *dev) +{ + struct evdev *evdev = container_of(dev, struct evdev, dev); + + input_put_device(evdev->handle.dev); + kfree(evdev); +} + +/* + * Grabs an event device (along with underlying input device). + * This function is called with evdev->mutex taken. + */ +static int evdev_grab(struct evdev *evdev, struct evdev_client *client) +{ + int error; + + if (evdev->grab) + return -EBUSY; + + error = input_grab_device(&evdev->handle); + if (error) + return error; + + rcu_assign_pointer(evdev->grab, client); + synchronize_rcu(); + + return 0; +} + +static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client) +{ + if (evdev->grab != client) + return -EINVAL; + + rcu_assign_pointer(evdev->grab, NULL); + synchronize_rcu(); + input_release_device(&evdev->handle); + + return 0; +} + +static void evdev_attach_client(struct evdev *evdev, + struct evdev_client *client) +{ + spin_lock(&evdev->client_lock); + list_add_tail_rcu(&client->node, &evdev->client_list); + spin_unlock(&evdev->client_lock); + synchronize_rcu(); +} + +static void evdev_detach_client(struct evdev *evdev, + struct evdev_client *client) +{ + spin_lock(&evdev->client_lock); + list_del_rcu(&client->node); + spin_unlock(&evdev->client_lock); + synchronize_rcu(); +} + +static int evdev_open_device(struct evdev *evdev) +{ + int retval; + + retval = mutex_lock_interruptible(&evdev->mutex); + if (retval) + return retval; + + if (!evdev->exist) + retval = -ENODEV; + else if (!evdev->open++) { + retval = input_open_device(&evdev->handle); + if (retval) + evdev->open--; + } + + mutex_unlock(&evdev->mutex); + return retval; +} + +static void evdev_close_device(struct evdev *evdev) +{ + mutex_lock(&evdev->mutex); + + if (evdev->exist && !--evdev->open) + input_close_device(&evdev->handle); + + mutex_unlock(&evdev->mutex); +} + +/* + * Wake up users waiting for IO so they can disconnect from + * dead device. + */ +static void evdev_hangup(struct evdev *evdev) +{ + struct evdev_client *client; + + spin_lock(&evdev->client_lock); + list_for_each_entry(client, &evdev->client_list, node) + kill_fasync(&client->fasync, SIGIO, POLL_HUP); + spin_unlock(&evdev->client_lock); + + wake_up_interruptible(&evdev->wait); +} + +static int evdev_release(struct inode *inode, struct file *file) +{ + struct evdev_client *client = file->private_data; + struct evdev *evdev = client->evdev; + + mutex_lock(&evdev->mutex); + if (evdev->grab == client) + evdev_ungrab(evdev, client); + mutex_unlock(&evdev->mutex); + + evdev_detach_client(evdev, client); + kfree(client); + + evdev_close_device(evdev); + put_device(&evdev->dev); + + return 0; +} + +static int evdev_open(struct inode *inode, struct file *file) +{ + struct evdev *evdev; + struct evdev_client *client; + int i = iminor(inode) - EVDEV_MINOR_BASE; + int error; + + if (i >= EVDEV_MINORS) + return -ENODEV; + + error = mutex_lock_interruptible(&evdev_table_mutex); + if (error) + return error; + evdev = evdev_table[i]; + if (evdev) + get_device(&evdev->dev); + mutex_unlock(&evdev_table_mutex); + + if (!evdev) + return -ENODEV; + + client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL); + if (!client) { + error = -ENOMEM; + goto err_put_evdev; + } + + spin_lock_init(&client->buffer_lock); + client->evdev = evdev; + evdev_attach_client(evdev, client); + + error = evdev_open_device(evdev); + if (error) + goto err_free_client; + + file->private_data = client; + return 0; + + err_free_client: + evdev_detach_client(evdev, client); + 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; +}; + +struct ff_periodic_effect_compat { + __u16 waveform; + __u16 period; + __s16 magnitude; + __s16 offset; + __u16 phase; + + struct ff_envelope envelope; + + __u32 custom_len; + compat_uptr_t custom_data; +}; + +struct ff_effect_compat { + __u16 type; + __s16 id; + __u16 direction; + struct ff_trigger trigger; + struct ff_replay replay; + + union { + struct ff_constant_effect constant; + struct ff_ramp_effect ramp; + struct ff_periodic_effect_compat periodic; + struct ff_condition_effect condition[2]; /* One for each axis */ + struct ff_rumble_effect rumble; + } u; +}; + +/* 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; +} + +static int evdev_ff_effect_from_user(const char __user *buffer, size_t size, + struct ff_effect *effect) +{ + if (COMPAT_TEST) { + struct ff_effect_compat *compat_effect; + + if (size != sizeof(struct ff_effect_compat)) + return -EINVAL; + + /* + * It so happens that the pointer which needs to be changed + * is the last field in the structure, so we can copy the + * whole thing and replace just the pointer. + */ + + compat_effect = (struct ff_effect_compat *)effect; + + if (copy_from_user(compat_effect, buffer, + sizeof(struct ff_effect_compat))) + return -EFAULT; + + if (compat_effect->type == FF_PERIODIC && + compat_effect->u.periodic.waveform == FF_CUSTOM) + effect->u.periodic.custom_data = + compat_ptr(compat_effect->u.periodic.custom_data); + } else { + if (size != sizeof(struct ff_effect)) + return -EINVAL; + + if (copy_from_user(effect, buffer, sizeof(struct ff_effect))) + 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; +} + +static int evdev_ff_effect_from_user(const char __user *buffer, size_t size, + struct ff_effect *effect) +{ + if (size != sizeof(struct ff_effect)) + return -EINVAL; + + if (copy_from_user(effect, buffer, sizeof(struct ff_effect))) + 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; + + retval = mutex_lock_interruptible(&evdev->mutex); + if (retval) + return retval; + + if (!evdev->exist) { + retval = -ENODEV; + goto out; + } + + while (retval < count) { + + if (evdev_event_from_user(buffer + retval, &event)) { + retval = -EFAULT; + goto out; + } + + input_inject_event(&evdev->handle, + event.type, event.code, event.value); + retval += evdev_event_size(); + } + + out: + mutex_unlock(&evdev->mutex); + return retval; +} + +static int evdev_fetch_next_event(struct evdev_client *client, + struct input_event *event) +{ + int have_event; + + spin_lock_irq(&client->buffer_lock); + + have_event = client->head != client->tail; + if (have_event) { + *event = client->buffer[client->tail++]; + client->tail &= EVDEV_BUFFER_SIZE - 1; + } + + spin_unlock_irq(&client->buffer_lock); + + return have_event; +} + +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; + struct input_event event; + 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 (retval + evdev_event_size() <= count && + evdev_fetch_next_event(client, &event)) { + + if (evdev_event_to_user(buffer + retval, &event)) + return -EFAULT; + + 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 BITS_TO_LONGS_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 = BITS_TO_LONGS_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 = BITS_TO_LONGS(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 ? + BITS_TO_LONGS_COMPAT(maxbit) * sizeof(compat_long_t) : + BITS_TO_LONGS(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 = BITS_TO_LONGS(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; +} + +#define OLD_KEY_MAX 0x1ff +static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user *p, int compat_mode) +{ + static unsigned long keymax_warn_time; + 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; + } + + /* + * Work around bugs in userspace programs that like to do + * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len' + * should be in bytes, not in bits. + */ + if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) { + len = OLD_KEY_MAX; + if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000)) + printk(KERN_WARNING + "evdev.c(EVIOCGBIT): Suspicious buffer size %u, " + "limiting output to %zu bytes. See " + "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n", + OLD_KEY_MAX, + BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long)); + } + + return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode); +} +#undef OLD_KEY_MAX + +static long evdev_do_ioctl(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; + + 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 = input_get_keycode(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 input_set_keycode(dev, t, v); + + 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) + return evdev_grab(evdev, client); + else + return evdev_ungrab(evdev, client); + + 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))) + return handle_eviocgbit(dev, 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) == _IOC_NR(EVIOCSFF)) { + + if (evdev_ff_effect_from_user(p, _IOC_SIZE(cmd), &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; + } + + 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; + + /* + * Take event lock to ensure that we are not + * changing device parameters in the middle + * of event. + */ + spin_lock_irq(&dev->event_lock); + + 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; + + spin_unlock_irq(&dev->event_lock); + + return 0; + } + } + } + return -EINVAL; +} + +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; + int retval; + + retval = mutex_lock_interruptible(&evdev->mutex); + if (retval) + return retval; + + if (!evdev->exist) { + retval = -ENODEV; + goto out; + } + + retval = evdev_do_ioctl(file, cmd, p, compat_mode); + + out: + mutex_unlock(&evdev->mutex); + return retval; +} + +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_install_chrdev(struct evdev *evdev) +{ + /* + * No need to do any locking here as calls to connect and + * disconnect are serialized by the input core + */ + evdev_table[evdev->minor] = evdev; + return 0; +} + +static void evdev_remove_chrdev(struct evdev *evdev) +{ + /* + * Lock evdev table to prevent race with evdev_open() + */ + mutex_lock(&evdev_table_mutex); + evdev_table[evdev->minor] = NULL; + mutex_unlock(&evdev_table_mutex); +} + +/* + * Mark device non-existent. This disables writes, ioctls and + * prevents new users from opening the device. Already posted + * blocking reads will stay, however new ones will fail. + */ +static void evdev_mark_dead(struct evdev *evdev) +{ + mutex_lock(&evdev->mutex); + evdev->exist = 0; + mutex_unlock(&evdev->mutex); +} + +static void evdev_cleanup(struct evdev *evdev) +{ + struct input_handle *handle = &evdev->handle; + + evdev_mark_dead(evdev); + evdev_hangup(evdev); + evdev_remove_chrdev(evdev); + + /* evdev is marked dead so no one else accesses evdev->open */ + if (evdev->open) { + input_flush_device(handle, NULL); + input_close_device(handle); + } +} + +/* + * Create new evdev device. Note that input core serializes calls + * to connect and disconnect so we don't need to lock evdev_table here. + */ +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; minor++) + if (!evdev_table[minor]) + break; + + 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); + spin_lock_init(&evdev->client_lock); + mutex_init(&evdev->mutex); + init_waitqueue_head(&evdev->wait); + + snprintf(evdev->name, sizeof(evdev->name), "event%d", minor); + evdev->exist = 1; + evdev->minor = minor; + + evdev->handle.dev = input_get_device(dev); + evdev->handle.name = evdev->name; + evdev->handle.handler = handler; + evdev->handle.private = evdev; + + strlcpy(evdev->dev.bus_id, evdev->name, sizeof(evdev->dev.bus_id)); + evdev->dev.devt = MKDEV(INPUT_MAJOR, EVDEV_MINOR_BASE + minor); + evdev->dev.class = &input_class; + evdev->dev.parent = &dev->dev; + evdev->dev.release = evdev_free; + device_initialize(&evdev->dev); + + error = input_register_handle(&evdev->handle); + if (error) + goto err_free_evdev; + + error = evdev_install_chrdev(evdev); + if (error) + goto err_unregister_handle; + + error = device_add(&evdev->dev); + if (error) + goto err_cleanup_evdev; + + return 0; + + err_cleanup_evdev: + evdev_cleanup(evdev); + err_unregister_handle: + input_unregister_handle(&evdev->handle); + err_free_evdev: + put_device(&evdev->dev); + return error; +} + +static void evdev_disconnect(struct input_handle *handle) +{ + struct evdev *evdev = handle->private; + + device_del(&evdev->dev); + evdev_cleanup(evdev); + input_unregister_handle(handle); + 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"); |