/* * The input core * * 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. */ #include <linux/init.h> #include <linux/types.h> #include <linux/input.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/random.h> #include <linux/major.h> #include <linux/proc_fs.h> #include <linux/sched.h> #include <linux/seq_file.h> #include <linux/poll.h> #include <linux/device.h> #include <linux/mutex.h> #include <linux/rcupdate.h> #include <linux/smp_lock.h> #include "input-compat.h" MODULE_AUTHOR("Vojtech Pavlik <vojtech@suse.cz>"); MODULE_DESCRIPTION("Input core"); MODULE_LICENSE("GPL"); #define INPUT_DEVICES 256 /* * EV_ABS events which should not be cached are listed here. */ static unsigned int input_abs_bypass_init_data[] __initdata = { ABS_MT_TOUCH_MAJOR, ABS_MT_TOUCH_MINOR, ABS_MT_WIDTH_MAJOR, ABS_MT_WIDTH_MINOR, ABS_MT_ORIENTATION, ABS_MT_POSITION_X, ABS_MT_POSITION_Y, ABS_MT_TOOL_TYPE, ABS_MT_BLOB_ID, ABS_MT_TRACKING_ID, ABS_MT_PRESSURE, 0 }; static unsigned long input_abs_bypass[BITS_TO_LONGS(ABS_CNT)]; static LIST_HEAD(input_dev_list); static LIST_HEAD(input_handler_list); /* * input_mutex protects access to both input_dev_list and input_handler_list. * This also causes input_[un]register_device and input_[un]register_handler * be mutually exclusive which simplifies locking in drivers implementing * input handlers. */ static DEFINE_MUTEX(input_mutex); static struct input_handler *input_table[8]; static inline int is_event_supported(unsigned int code, unsigned long *bm, unsigned int max) { return code <= max && test_bit(code, bm); } static int input_defuzz_abs_event(int value, int old_val, int fuzz) { if (fuzz) { if (value > old_val - fuzz / 2 && value < old_val + fuzz / 2) return old_val; if (value > old_val - fuzz && value < old_val + fuzz) return (old_val * 3 + value) / 4; if (value > old_val - fuzz * 2 && value < old_val + fuzz * 2) return (old_val + value) / 2; } return value; } /* * Pass event first through all filters and then, if event has not been * filtered out, through all open handles. This function is called with * dev->event_lock held and interrupts disabled. */ static void input_pass_event(struct input_dev *dev, unsigned int type, unsigned int code, int value) { struct input_handler *handler; struct input_handle *handle; rcu_read_lock(); handle = rcu_dereference(dev->grab); if (handle) handle->handler->event(handle, type, code, value); else { bool filtered = false; list_for_each_entry_rcu(handle, &dev->h_list, d_node) { if (!handle->open) continue; handler = handle->handler; if (!handler->filter) { if (filtered) break; handler->event(handle, type, code, value); } else if (handler->filter(handle, type, code, value)) filtered = true; } } rcu_read_unlock(); } /* * Generate software autorepeat event. Note that we take * dev->event_lock here to avoid racing with input_event * which may cause keys get "stuck". */ static void input_repeat_key(unsigned long data) { struct input_dev *dev = (void *) data; unsigned long flags; spin_lock_irqsave(&dev->event_lock, flags); if (test_bit(dev->repeat_key, dev->key) && is_event_supported(dev->repeat_key, dev->keybit, KEY_MAX)) { input_pass_event(dev, EV_KEY, dev->repeat_key, 2); if (dev->sync) { /* * Only send SYN_REPORT if we are not in a middle * of driver parsing a new hardware packet. * Otherwise assume that the driver will send * SYN_REPORT once it's done. */ input_pass_event(dev, EV_SYN, SYN_REPORT, 1); } if (dev->rep[REP_PERIOD]) mod_timer(&dev->timer, jiffies + msecs_to_jiffies(dev->rep[REP_PERIOD])); } spin_unlock_irqrestore(&dev->event_lock, flags); } static void input_start_autorepeat(struct input_dev *dev, int code) { if (test_bit(EV_REP, dev->evbit) && dev->rep[REP_PERIOD] && dev->rep[REP_DELAY] && dev->timer.data) { dev->repeat_key = code; mod_timer(&dev->timer, jiffies + msecs_to_jiffies(dev->rep[REP_DELAY])); } } static void input_stop_autorepeat(struct input_dev *dev) { del_timer(&dev->timer); } #define INPUT_IGNORE_EVENT 0 #define INPUT_PASS_TO_HANDLERS 1 #define INPUT_PASS_TO_DEVICE 2 #define INPUT_PASS_TO_ALL (INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE) static void input_handle_event(struct input_dev *dev, unsigned int type, unsigned int code, int value) { int disposition = INPUT_IGNORE_EVENT; switch (type) { case EV_SYN: switch (code) { case SYN_CONFIG: disposition = INPUT_PASS_TO_ALL; break; case SYN_REPORT: if (!dev->sync) { dev->sync = 1; disposition = INPUT_PASS_TO_HANDLERS; } break; case SYN_MT_REPORT: dev->sync = 0; disposition = INPUT_PASS_TO_HANDLERS; break; } break; case EV_KEY: if (is_event_supported(code, dev->keybit, KEY_MAX) && !!test_bit(code, dev->key) != value) { if (value != 2) { __change_bit(code, dev->key); if (value) input_start_autorepeat(dev, code); else input_stop_autorepeat(dev); } disposition = INPUT_PASS_TO_HANDLERS; } break; case EV_SW: if (is_event_supported(code, dev->swbit, SW_MAX) && !!test_bit(code, dev->sw) != value) { __change_bit(code, dev->sw); disposition = INPUT_PASS_TO_HANDLERS; } break; case EV_ABS: if (is_event_supported(code, dev->absbit, ABS_MAX)) { if (test_bit(code, input_abs_bypass)) { disposition = INPUT_PASS_TO_HANDLERS; break; } value = input_defuzz_abs_event(value, dev->abs[code], dev->absfuzz[code]); if (dev->abs[code] != value) { dev->abs[code] = value; disposition = INPUT_PASS_TO_HANDLERS; } } break; case EV_REL: if (is_event_supported(code, dev->relbit, REL_MAX) && value) disposition = INPUT_PASS_TO_HANDLERS; break; case EV_MSC: if (is_event_supported(code, dev->mscbit, MSC_MAX)) disposition = INPUT_PASS_TO_ALL; break; case EV_LED: if (is_event_supported(code, dev->ledbit, LED_MAX) && !!test_bit(code, dev->led) != value) { __change_bit(code, dev->led); disposition = INPUT_PASS_TO_ALL; } break; case EV_SND: if (is_event_supported(code, dev->sndbit, SND_MAX)) { if (!!test_bit(code, dev->snd) != !!value) __change_bit(code, dev->snd); disposition = INPUT_PASS_TO_ALL; } break; case EV_REP: if (code <= REP_MAX && value >= 0 && dev->rep[code] != value) { dev->rep[code] = value; disposition = INPUT_PASS_TO_ALL; } break; case EV_FF: if (value >= 0) disposition = INPUT_PASS_TO_ALL; break; case EV_PWR: disposition = INPUT_PASS_TO_ALL; break; } if (disposition != INPUT_IGNORE_EVENT && type != EV_SYN) dev->sync = 0; if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event) dev->event(dev, type, code, value); if (disposition & INPUT_PASS_TO_HANDLERS) input_pass_event(dev, type, code, value); } /** * input_event() - report new input event * @dev: device that generated the event * @type: type of the event * @code: event code * @value: value of the event * * This function should be used by drivers implementing various input * devices to report input events. See also input_inject_event(). * * NOTE: input_event() may be safely used right after input device was * allocated with input_allocate_device(), even before it is registered * with input_register_device(), but the event will not reach any of the * input handlers. Such early invocation of input_event() may be used * to 'seed' initial state of a switch or initial position of absolute * axis, etc. */ void input_event(struct input_dev *dev, unsigned int type, unsigned int code, int value) { unsigned long flags; if (is_event_supported(type, dev->evbit, EV_MAX)) { spin_lock_irqsave(&dev->event_lock, flags); add_input_randomness(type, code, value); input_handle_event(dev, type, code, value); spin_unlock_irqrestore(&dev->event_lock, flags); } } EXPORT_SYMBOL(input_event); /** * input_inject_event() - send input event from input handler * @handle: input handle to send event through * @type: type of the event * @code: event code * @value: value of the event * * Similar to input_event() but will ignore event if device is * "grabbed" and handle injecting event is not the one that owns * the device. */ void input_inject_event(struct input_handle *handle, unsigned int type, unsigned int code, int value) { struct input_dev *dev = handle->dev; struct input_handle *grab; unsigned long flags; if (is_event_supported(type, dev->evbit, EV_MAX)) { spin_lock_irqsave(&dev->event_lock, flags); rcu_read_lock(); grab = rcu_dereference(dev->grab); if (!grab || grab == handle) input_handle_event(dev, type, code, value); rcu_read_unlock(); spin_unlock_irqrestore(&dev->event_lock, flags); } } EXPORT_SYMBOL(input_inject_event); /** * input_grab_device - grabs device for exclusive use * @handle: input handle that wants to own the device * * When a device is grabbed by an input handle all events generated by * the device are delivered only to this handle. Also events injected * by other input handles are ignored while device is grabbed. */ int input_grab_device(struct input_handle *handle) { struct input_dev *dev = handle->dev; int retval; retval = mutex_lock_interruptible(&dev->mutex); if (retval) return retval; if (dev->grab) { retval = -EBUSY; goto out; } rcu_assign_pointer(dev->grab, handle); synchronize_rcu(); out: mutex_unlock(&dev->mutex); return retval; } EXPORT_SYMBOL(input_grab_device); static void __input_release_device(struct input_handle *handle) { struct input_dev *dev = handle->dev; if (dev->grab == handle) { rcu_assign_pointer(dev->grab, NULL); /* Make sure input_pass_event() notices that grab is gone */ synchronize_rcu(); list_for_each_entry(handle, &dev->h_list, d_node) if (handle->open && handle->handler->start) handle->handler->start(handle); } } /** * input_release_device - release previously grabbed device * @handle: input handle that owns the device * * Releases previously grabbed device so that other input handles can * start receiving input events. Upon release all handlers attached * to the device have their start() method called so they have a change * to synchronize device state with the rest of the system. */ void input_release_device(struct input_handle *handle) { struct input_dev *dev = handle->dev; mutex_lock(&dev->mutex); __input_release_device(handle); mutex_unlock(&dev->mutex); } EXPORT_SYMBOL(input_release_device); /** * input_open_device - open input device * @handle: handle through which device is being accessed * * This function should be called by input handlers when they * want to start receive events from given input device. */ int input_open_device(struct input_handle *handle) { struct input_dev *dev = handle->dev; int retval; retval = mutex_lock_interruptible(&dev->mutex); if (retval) return retval; if (dev->going_away) { retval = -ENODEV; goto out; } handle->open++; if (!dev->users++ && dev->open) retval = dev->open(dev); if (retval) { dev->users--; if (!--handle->open) { /* * Make sure we are not delivering any more events * through this handle */ synchronize_rcu(); } } out: mutex_unlock(&dev->mutex); return retval; } EXPORT_SYMBOL(input_open_device); int input_flush_device(struct input_handle *handle, struct file *file) { struct input_dev *dev = handle->dev; int retval; retval = mutex_lock_interruptible(&dev->mutex); if (retval) return retval; if (dev->flush) retval = dev->flush(dev, file); mutex_unlock(&dev->mutex); return retval; } EXPORT_SYMBOL(input_flush_device); /** * input_close_device - close input device * @handle: handle through which device is being accessed * * This function should be called by input handlers when they * want to stop receive events from given input device. */ void input_close_device(struct input_handle *handle) { struct input_dev *dev = handle->dev; mutex_lock(&dev->mutex); __input_release_device(handle); if (!--dev->users && dev->close) dev->close(dev); if (!--handle->open) { /* * synchronize_rcu() makes sure that input_pass_event() * completed and that no more input events are delivered * through this handle */ synchronize_rcu(); } mutex_unlock(&dev->mutex); } EXPORT_SYMBOL(input_close_device); /* * Prepare device for unregistering */ static void input_disconnect_device(struct input_dev *dev) { struct input_handle *handle; int code; /* * Mark device as going away. Note that we take dev->mutex here * not to protect access to dev->going_away but rather to ensure * that there are no threads in the middle of input_open_device() */ mutex_lock(&dev->mutex); dev->going_away = true; mutex_unlock(&dev->mutex); spin_lock_irq(&dev->event_lock); /* * Simulate keyup events for all pressed keys so that handlers * are not left with "stuck" keys. The driver may continue * generate events even after we done here but they will not * reach any handlers. */ if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) { for (code = 0; code <= KEY_MAX; code++) { if (is_event_supported(code, dev->keybit, KEY_MAX) && __test_and_clear_bit(code, dev->key)) { input_pass_event(dev, EV_KEY, code, 0); } } input_pass_event(dev, EV_SYN, SYN_REPORT, 1); } list_for_each_entry(handle, &dev->h_list, d_node) handle->open = 0; spin_unlock_irq(&dev->event_lock); } static int input_fetch_keycode(struct input_dev *dev, int scancode) { switch (dev->keycodesize) { case 1: return ((u8 *)dev->keycode)[scancode]; case 2: return ((u16 *)dev->keycode)[scancode]; default: return ((u32 *)dev->keycode)[scancode]; } } static int input_default_getkeycode(struct input_dev *dev, unsigned int scancode, unsigned int *keycode) { if (!dev->keycodesize) return -EINVAL; if (scancode >= dev->keycodemax) return -EINVAL; *keycode = input_fetch_keycode(dev, scancode); return 0; } static int input_default_setkeycode(struct input_dev *dev, unsigned int scancode, unsigned int keycode) { int old_keycode; int i; if (scancode >= dev->keycodemax) return -EINVAL; if (!dev->keycodesize) return -EINVAL; if (dev->keycodesize < sizeof(keycode) && (keycode >> (dev->keycodesize * 8))) return -EINVAL; switch (dev->keycodesize) { case 1: { u8 *k = (u8 *)dev->keycode; old_keycode = k[scancode]; k[scancode] = keycode; break; } case 2: { u16 *k = (u16 *)dev->keycode; old_keycode = k[scancode]; k[scancode] = keycode; break; } default: { u32 *k = (u32 *)dev->keycode; old_keycode = k[scancode]; k[scancode] = keycode; break; } } __clear_bit(old_keycode, dev->keybit); __set_bit(keycode, dev->keybit); for (i = 0; i < dev->keycodemax; i++) { if (input_fetch_keycode(dev, i) == old_keycode) { __set_bit(old_keycode, dev->keybit); break; /* Setting the bit twice is useless, so break */ } } return 0; } /** * input_get_keycode - retrieve keycode currently mapped to a given scancode * @dev: input device which keymap is being queried * @scancode: scancode (or its equivalent for device in question) for which * keycode is needed * @keycode: result * * This function should be called by anyone interested in retrieving current * keymap. Presently keyboard and evdev handlers use it. */ int input_get_keycode(struct input_dev *dev, unsigned int scancode, unsigned int *keycode) { unsigned long flags; int retval; spin_lock_irqsave(&dev->event_lock, flags); retval = dev->getkeycode(dev, scancode, keycode); spin_unlock_irqrestore(&dev->event_lock, flags); return retval; } EXPORT_SYMBOL(input_get_keycode); /** * input_get_keycode - assign new keycode to a given scancode * @dev: input device which keymap is being updated * @scancode: scancode (or its equivalent for device in question) * @keycode: new keycode to be assigned to the scancode * * This function should be called by anyone needing to update current * keymap. Presently keyboard and evdev handlers use it. */ int input_set_keycode(struct input_dev *dev, unsigned int scancode, unsigned int keycode) { unsigned long flags; int old_keycode; int retval; if (keycode > KEY_MAX) return -EINVAL; spin_lock_irqsave(&dev->event_lock, flags); retval = dev->getkeycode(dev, scancode, &old_keycode); if (retval) goto out; retval = dev->setkeycode(dev, scancode, keycode); if (retval) goto out; /* Make sure KEY_RESERVED did not get enabled. */ __clear_bit(KEY_RESERVED, dev->keybit); /* * Simulate keyup event if keycode is not present * in the keymap anymore */ if (test_bit(EV_KEY, dev->evbit) && !is_event_supported(old_keycode, dev->keybit, KEY_MAX) && __test_and_clear_bit(old_keycode, dev->key)) { input_pass_event(dev, EV_KEY, old_keycode, 0); if (dev->sync) input_pass_event(dev, EV_SYN, SYN_REPORT, 1); } out: spin_unlock_irqrestore(&dev->event_lock, flags); return retval; } EXPORT_SYMBOL(input_set_keycode); #define MATCH_BIT(bit, max) \ for (i = 0; i < BITS_TO_LONGS(max); i++) \ if ((id->bit[i] & dev->bit[i]) != id->bit[i]) \ break; \ if (i != BITS_TO_LONGS(max)) \ continue; static const struct input_device_id *input_match_device(struct input_handler *handler, struct input_dev *dev) { const struct input_device_id *id; int i; for (id = handler->id_table; id->flags || id->driver_info; id++) { if (id->flags & INPUT_DEVICE_ID_MATCH_BUS) if (id->bustype != dev->id.bustype) continue; if (id->flags & INPUT_DEVICE_ID_MATCH_VENDOR) if (id->vendor != dev->id.vendor) continue; if (id->flags & INPUT_DEVICE_ID_MATCH_PRODUCT) if (id->product != dev->id.product) continue; if (id->flags & INPUT_DEVICE_ID_MATCH_VERSION) if (id->version != dev->id.version) continue; MATCH_BIT(evbit, EV_MAX); MATCH_BIT(keybit, KEY_MAX); MATCH_BIT(relbit, REL_MAX); MATCH_BIT(absbit, ABS_MAX); MATCH_BIT(mscbit, MSC_MAX); MATCH_BIT(ledbit, LED_MAX); MATCH_BIT(sndbit, SND_MAX); MATCH_BIT(ffbit, FF_MAX); MATCH_BIT(swbit, SW_MAX); if (!handler->match || handler->match(handler, dev)) return id; } return NULL; } static int input_attach_handler(struct input_dev *dev, struct input_handler *handler) { const struct input_device_id *id; int error; id = input_match_device(handler, dev); if (!id) return -ENODEV; error = handler->connect(handler, dev, id); if (error && error != -ENODEV) printk(KERN_ERR "input: failed to attach handler %s to device %s, " "error: %d\n", handler->name, kobject_name(&dev->dev.kobj), error); return error; } #ifdef CONFIG_COMPAT static int input_bits_to_string(char *buf, int buf_size, unsigned long bits, bool skip_empty) { int len = 0; if (INPUT_COMPAT_TEST) { u32 dword = bits >> 32; if (dword || !skip_empty) len += snprintf(buf, buf_size, "%x ", dword); dword = bits & 0xffffffffUL; if (dword || !skip_empty || len) len += snprintf(buf + len, max(buf_size - len, 0), "%x", dword); } else { if (bits || !skip_empty) len += snprintf(buf, buf_size, "%lx", bits); } return len; } #else /* !CONFIG_COMPAT */ static int input_bits_to_string(char *buf, int buf_size, unsigned long bits, bool skip_empty) { return bits || !skip_empty ? snprintf(buf, buf_size, "%lx", bits) : 0; } #endif #ifdef CONFIG_PROC_FS static struct proc_dir_entry *proc_bus_input_dir; static DECLARE_WAIT_QUEUE_HEAD(input_devices_poll_wait); static int input_devices_state; static inline void input_wakeup_procfs_readers(void) { input_devices_state++; wake_up(&input_devices_poll_wait); } static unsigned int input_proc_devices_poll(struct file *file, poll_table *wait) { poll_wait(file, &input_devices_poll_wait, wait); if (file->f_version != input_devices_state) { file->f_version = input_devices_state; return POLLIN | POLLRDNORM; } return 0; } union input_seq_state { struct { unsigned short pos; bool mutex_acquired; }; void *p; }; static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos) { union input_seq_state *state = (union input_seq_state *)&seq->private; int error; /* We need to fit into seq->private pointer */ BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private)); error = mutex_lock_interruptible(&input_mutex); if (error) { state->mutex_acquired = false; return ERR_PTR(error); } state->mutex_acquired = true; return seq_list_start(&input_dev_list, *pos); } static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos) { return seq_list_next(v, &input_dev_list, pos); } static void input_seq_stop(struct seq_file *seq, void *v) { union input_seq_state *state = (union input_seq_state *)&seq->private; if (state->mutex_acquired) mutex_unlock(&input_mutex); } static void input_seq_print_bitmap(struct seq_file *seq, const char *name, unsigned long *bitmap, int max) { int i; bool skip_empty = true; char buf[18]; seq_printf(seq, "B: %s=", name); for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) { if (input_bits_to_string(buf, sizeof(buf), bitmap[i], skip_empty)) { skip_empty = false; seq_printf(seq, "%s%s", buf, i > 0 ? " " : ""); } } /* * If no output was produced print a single 0. */ if (skip_empty) seq_puts(seq, "0"); seq_putc(seq, '\n'); } static int input_devices_seq_show(struct seq_file *seq, void *v) { struct input_dev *dev = container_of(v, struct input_dev, node); const char *path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL); struct input_handle *handle; seq_printf(seq, "I: Bus=%04x Vendor=%04x Product=%04x Version=%04x\n", dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version); seq_printf(seq, "N: Name=\"%s\"\n", dev->name ? dev->name : ""); seq_printf(seq, "P: Phys=%s\n", dev->phys ? dev->phys : ""); seq_printf(seq, "S: Sysfs=%s\n", path ? path : ""); seq_printf(seq, "U: Uniq=%s\n", dev->uniq ? dev->uniq : ""); seq_printf(seq, "H: Handlers="); list_for_each_entry(handle, &dev->h_list, d_node) seq_printf(seq, "%s ", handle->name); seq_putc(seq, '\n'); input_seq_print_bitmap(seq, "EV", dev->evbit, EV_MAX); if (test_bit(EV_KEY, dev->evbit)) input_seq_print_bitmap(seq, "KEY", dev->keybit, KEY_MAX); if (test_bit(EV_REL, dev->evbit)) input_seq_print_bitmap(seq, "REL", dev->relbit, REL_MAX); if (test_bit(EV_ABS, dev->evbit)) input_seq_print_bitmap(seq, "ABS", dev->absbit, ABS_MAX); if (test_bit(EV_MSC, dev->evbit)) input_seq_print_bitmap(seq, "MSC", dev->mscbit, MSC_MAX); if (test_bit(EV_LED, dev->evbit)) input_seq_print_bitmap(seq, "LED", dev->ledbit, LED_MAX); if (test_bit(EV_SND, dev->evbit)) input_seq_print_bitmap(seq, "SND", dev->sndbit, SND_MAX); if (test_bit(EV_FF, dev->evbit)) input_seq_print_bitmap(seq, "FF", dev->ffbit, FF_MAX); if (test_bit(EV_SW, dev->evbit)) input_seq_print_bitmap(seq, "SW", dev->swbit, SW_MAX); seq_putc(seq, '\n'); kfree(path); return 0; } static const struct seq_operations input_devices_seq_ops = { .start = input_devices_seq_start, .next = input_devices_seq_next, .stop = input_seq_stop, .show = input_devices_seq_show, }; static int input_proc_devices_open(struct inode *inode, struct file *file) { return seq_open(file, &input_devices_seq_ops); } static const struct file_operations input_devices_fileops = { .owner = THIS_MODULE, .open = input_proc_devices_open, .poll = input_proc_devices_poll, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos) { union input_seq_state *state = (union input_seq_state *)&seq->private; int error; /* We need to fit into seq->private pointer */ BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private)); error = mutex_lock_interruptible(&input_mutex); if (error) { state->mutex_acquired = false; return ERR_PTR(error); } state->mutex_acquired = true; state->pos = *pos; return seq_list_start(&input_handler_list, *pos); } static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos) { union input_seq_state *state = (union input_seq_state *)&seq->private; state->pos = *pos + 1; return seq_list_next(v, &input_handler_list, pos); } static int input_handlers_seq_show(struct seq_file *seq, void *v) { struct input_handler *handler = container_of(v, struct input_handler, node); union input_seq_state *state = (union input_seq_state *)&seq->private; seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name); if (handler->filter) seq_puts(seq, " (filter)"); if (handler->fops) seq_printf(seq, " Minor=%d", handler->minor); seq_putc(seq, '\n'); return 0; } static const struct seq_operations input_handlers_seq_ops = { .start = input_handlers_seq_start, .next = input_handlers_seq_next, .stop = input_seq_stop, .show = input_handlers_seq_show, }; static int input_proc_handlers_open(struct inode *inode, struct file *file) { return seq_open(file, &input_handlers_seq_ops); } static const struct file_operations input_handlers_fileops = { .owner = THIS_MODULE, .open = input_proc_handlers_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; static int __init input_proc_init(void) { struct proc_dir_entry *entry; proc_bus_input_dir = proc_mkdir("bus/input", NULL); if (!proc_bus_input_dir) return -ENOMEM; entry = proc_create("devices", 0, proc_bus_input_dir, &input_devices_fileops); if (!entry) goto fail1; entry = proc_create("handlers", 0, proc_bus_input_dir, &input_handlers_fileops); if (!entry) goto fail2; return 0; fail2: remove_proc_entry("devices", proc_bus_input_dir); fail1: remove_proc_entry("bus/input", NULL); return -ENOMEM; } static void input_proc_exit(void) { remove_proc_entry("devices", proc_bus_input_dir); remove_proc_entry("handlers", proc_bus_input_dir); remove_proc_entry("bus/input", NULL); } #else /* !CONFIG_PROC_FS */ static inline void input_wakeup_procfs_readers(void) { } static inline int input_proc_init(void) { return 0; } static inline void input_proc_exit(void) { } #endif #define INPUT_DEV_STRING_ATTR_SHOW(name) \ static ssize_t input_dev_show_##name(struct device *dev, \ struct device_attribute *attr, \ char *buf) \ { \ struct input_dev *input_dev = to_input_dev(dev); \ \ return scnprintf(buf, PAGE_SIZE, "%s\n", \ input_dev->name ? input_dev->name : ""); \ } \ static DEVICE_ATTR(name, S_IRUGO, input_dev_show_##name, NULL) INPUT_DEV_STRING_ATTR_SHOW(name); INPUT_DEV_STRING_ATTR_SHOW(phys); INPUT_DEV_STRING_ATTR_SHOW(uniq); static int input_print_modalias_bits(char *buf, int size, char name, unsigned long *bm, unsigned int min_bit, unsigned int max_bit) { int len = 0, i; len += snprintf(buf, max(size, 0), "%c", name); for (i = min_bit; i < max_bit; i++) if (bm[BIT_WORD(i)] & BIT_MASK(i)) len += snprintf(buf + len, max(size - len, 0), "%X,", i); return len; } static int input_print_modalias(char *buf, int size, struct input_dev *id, int add_cr) { int len; len = snprintf(buf, max(size, 0), "input:b%04Xv%04Xp%04Xe%04X-", id->id.bustype, id->id.vendor, id->id.product, id->id.version); len += input_print_modalias_bits(buf + len, size - len, 'e', id->evbit, 0, EV_MAX); len += input_print_modalias_bits(buf + len, size - len, 'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX); len += input_print_modalias_bits(buf + len, size - len, 'r', id->relbit, 0, REL_MAX); len += input_print_modalias_bits(buf + len, size - len, 'a', id->absbit, 0, ABS_MAX); len += input_print_modalias_bits(buf + len, size - len, 'm', id->mscbit, 0, MSC_MAX); len += input_print_modalias_bits(buf + len, size - len, 'l', id->ledbit, 0, LED_MAX); len += input_print_modalias_bits(buf + len, size - len, 's', id->sndbit, 0, SND_MAX); len += input_print_modalias_bits(buf + len, size - len, 'f', id->ffbit, 0, FF_MAX); len += input_print_modalias_bits(buf + len, size - len, 'w', id->swbit, 0, SW_MAX); if (add_cr) len += snprintf(buf + len, max(size - len, 0), "\n"); return len; } static ssize_t input_dev_show_modalias(struct device *dev, struct device_attribute *attr, char *buf) { struct input_dev *id = to_input_dev(dev); ssize_t len; len = input_print_modalias(buf, PAGE_SIZE, id, 1); return min_t(int, len, PAGE_SIZE); } static DEVICE_ATTR(modalias, S_IRUGO, input_dev_show_modalias, NULL); static struct attribute *input_dev_attrs[] = { &dev_attr_name.attr, &dev_attr_phys.attr, &dev_attr_uniq.attr, &dev_attr_modalias.attr, NULL }; static struct attribute_group input_dev_attr_group = { .attrs = input_dev_attrs, }; #define INPUT_DEV_ID_ATTR(name) \ static ssize_t input_dev_show_id_##name(struct device *dev, \ struct device_attribute *attr, \ char *buf) \ { \ struct input_dev *input_dev = to_input_dev(dev); \ return scnprintf(buf, PAGE_SIZE, "%04x\n", input_dev->id.name); \ } \ static DEVICE_ATTR(name, S_IRUGO, input_dev_show_id_##name, NULL) INPUT_DEV_ID_ATTR(bustype); INPUT_DEV_ID_ATTR(vendor); INPUT_DEV_ID_ATTR(product); INPUT_DEV_ID_ATTR(version); static struct attribute *input_dev_id_attrs[] = { &dev_attr_bustype.attr, &dev_attr_vendor.attr, &dev_attr_product.attr, &dev_attr_version.attr, NULL }; static struct attribute_group input_dev_id_attr_group = { .name = "id", .attrs = input_dev_id_attrs, }; static int input_print_bitmap(char *buf, int buf_size, unsigned long *bitmap, int max, int add_cr) { int i; int len = 0; bool skip_empty = true; for (i = BITS_TO_LONGS(max) - 1; i >= 0; i--) { len += input_bits_to_string(buf + len, max(buf_size - len, 0), bitmap[i], skip_empty); if (len) { skip_empty = false; if (i > 0) len += snprintf(buf + len, max(buf_size - len, 0), " "); } } /* * If no output was produced print a single 0. */ if (len == 0) len = snprintf(buf, buf_size, "%d", 0); if (add_cr) len += snprintf(buf + len, max(buf_size - len, 0), "\n"); return len; } #define INPUT_DEV_CAP_ATTR(ev, bm) \ static ssize_t input_dev_show_cap_##bm(struct device *dev, \ struct device_attribute *attr, \ char *buf) \ { \ struct input_dev *input_dev = to_input_dev(dev); \ int len = input_print_bitmap(buf, PAGE_SIZE, \ input_dev->bm##bit, ev##_MAX, \ true); \ return min_t(int, len, PAGE_SIZE); \ } \ static DEVICE_ATTR(bm, S_IRUGO, input_dev_show_cap_##bm, NULL) INPUT_DEV_CAP_ATTR(EV, ev); INPUT_DEV_CAP_ATTR(KEY, key); INPUT_DEV_CAP_ATTR(REL, rel); INPUT_DEV_CAP_ATTR(ABS, abs); INPUT_DEV_CAP_ATTR(MSC, msc); INPUT_DEV_CAP_ATTR(LED, led); INPUT_DEV_CAP_ATTR(SND, snd); INPUT_DEV_CAP_ATTR(FF, ff); INPUT_DEV_CAP_ATTR(SW, sw); static struct attribute *input_dev_caps_attrs[] = { &dev_attr_ev.attr, &dev_attr_key.attr, &dev_attr_rel.attr, &dev_attr_abs.attr, &dev_attr_msc.attr, &dev_attr_led.attr, &dev_attr_snd.attr, &dev_attr_ff.attr, &dev_attr_sw.attr, NULL }; static struct attribute_group input_dev_caps_attr_group = { .name = "capabilities", .attrs = input_dev_caps_attrs, }; static const struct attribute_group *input_dev_attr_groups[] = { &input_dev_attr_group, &input_dev_id_attr_group, &input_dev_caps_attr_group, NULL }; static void input_dev_release(struct device *device) { struct input_dev *dev = to_input_dev(device); input_ff_destroy(dev); kfree(dev); module_put(THIS_MODULE); } /* * Input uevent interface - loading event handlers based on * device bitfields. */ static int input_add_uevent_bm_var(struct kobj_uevent_env *env, const char *name, unsigned long *bitmap, int max) { int len; if (add_uevent_var(env, "%s=", name)) return -ENOMEM; len = input_print_bitmap(&env->buf[env->buflen - 1], sizeof(env->buf) - env->buflen, bitmap, max, false); if (len >= (sizeof(env->buf) - env->buflen)) return -ENOMEM; env->buflen += len; return 0; } static int input_add_uevent_modalias_var(struct kobj_uevent_env *env, struct input_dev *dev) { int len; if (add_uevent_var(env, "MODALIAS=")) return -ENOMEM; len = input_print_modalias(&env->buf[env->buflen - 1], sizeof(env->buf) - env->buflen, dev, 0); if (len >= (sizeof(env->buf) - env->buflen)) return -ENOMEM; env->buflen += len; return 0; } #define INPUT_ADD_HOTPLUG_VAR(fmt, val...) \ do { \ int err = add_uevent_var(env, fmt, val); \ if (err) \ return err; \ } while (0) #define INPUT_ADD_HOTPLUG_BM_VAR(name, bm, max) \ do { \ int err = input_add_uevent_bm_var(env, name, bm, max); \ if (err) \ return err; \ } while (0) #define INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev) \ do { \ int err = input_add_uevent_modalias_var(env, dev); \ if (err) \ return err; \ } while (0) static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env) { struct input_dev *dev = to_input_dev(device); INPUT_ADD_HOTPLUG_VAR("PRODUCT=%x/%x/%x/%x", dev->id.bustype, dev->id.vendor, dev->id.product, dev->id.version); if (dev->name) INPUT_ADD_HOTPLUG_VAR("NAME=\"%s\"", dev->name); if (dev->phys) INPUT_ADD_HOTPLUG_VAR("PHYS=\"%s\"", dev->phys); if (dev->uniq) INPUT_ADD_HOTPLUG_VAR("UNIQ=\"%s\"", dev->uniq); INPUT_ADD_HOTPLUG_BM_VAR("EV=", dev->evbit, EV_MAX); if (test_bit(EV_KEY, dev->evbit)) INPUT_ADD_HOTPLUG_BM_VAR("KEY=", dev->keybit, KEY_MAX); if (test_bit(EV_REL, dev->evbit)) INPUT_ADD_HOTPLUG_BM_VAR("REL=", dev->relbit, REL_MAX); if (test_bit(EV_ABS, dev->evbit)) INPUT_ADD_HOTPLUG_BM_VAR("ABS=", dev->absbit, ABS_MAX); if (test_bit(EV_MSC, dev->evbit)) INPUT_ADD_HOTPLUG_BM_VAR("MSC=", dev->mscbit, MSC_MAX); if (test_bit(EV_LED, dev->evbit)) INPUT_ADD_HOTPLUG_BM_VAR("LED=", dev->ledbit, LED_MAX); if (test_bit(EV_SND, dev->evbit)) INPUT_ADD_HOTPLUG_BM_VAR("SND=", dev->sndbit, SND_MAX); if (test_bit(EV_FF, dev->evbit)) INPUT_ADD_HOTPLUG_BM_VAR("FF=", dev->ffbit, FF_MAX); if (test_bit(EV_SW, dev->evbit)) INPUT_ADD_HOTPLUG_BM_VAR("SW=", dev->swbit, SW_MAX); INPUT_ADD_HOTPLUG_MODALIAS_VAR(dev); return 0; } #define INPUT_DO_TOGGLE(dev, type, bits, on) \ do { \ int i; \ bool active; \ \ if (!test_bit(EV_##type, dev->evbit)) \ break; \ \ for (i = 0; i < type##_MAX; i++) { \ if (!test_bit(i, dev->bits##bit)) \ continue; \ \ active = test_bit(i, dev->bits); \ if (!active && !on) \ continue; \ \ dev->event(dev, EV_##type, i, on ? active : 0); \ } \ } while (0) #ifdef CONFIG_PM static void input_dev_reset(struct input_dev *dev, bool activate) { if (!dev->event) return; INPUT_DO_TOGGLE(dev, LED, led, activate); INPUT_DO_TOGGLE(dev, SND, snd, activate); if (activate && test_bit(EV_REP, dev->evbit)) { dev->event(dev, EV_REP, REP_PERIOD, dev->rep[REP_PERIOD]); dev->event(dev, EV_REP, REP_DELAY, dev->rep[REP_DELAY]); } } static int input_dev_suspend(struct device *dev) { struct input_dev *input_dev = to_input_dev(dev); mutex_lock(&input_dev->mutex); input_dev_reset(input_dev, false); mutex_unlock(&input_dev->mutex); return 0; } static int input_dev_resume(struct device *dev) { struct input_dev *input_dev = to_input_dev(dev); mutex_lock(&input_dev->mutex); input_dev_reset(input_dev, true); mutex_unlock(&input_dev->mutex); return 0; } static const struct dev_pm_ops input_dev_pm_ops = { .suspend = input_dev_suspend, .resume = input_dev_resume, .poweroff = input_dev_suspend, .restore = input_dev_resume, }; #endif /* CONFIG_PM */ static struct device_type input_dev_type = { .groups = input_dev_attr_groups, .release = input_dev_release, .uevent = input_dev_uevent, #ifdef CONFIG_PM .pm = &input_dev_pm_ops, #endif }; static char *input_devnode(struct device *dev, mode_t *mode) { return kasprintf(GFP_KERNEL, "input/%s", dev_name(dev)); } struct class input_class = { .name = "input", .devnode = input_devnode, }; EXPORT_SYMBOL_GPL(input_class); /** * input_allocate_device - allocate memory for new input device * * Returns prepared struct input_dev or NULL. * * NOTE: Use input_free_device() to free devices that have not been * registered; input_unregister_device() should be used for already * registered devices. */ struct input_dev *input_allocate_device(void) { struct input_dev *dev; dev = kzalloc(sizeof(struct input_dev), GFP_KERNEL); if (dev) { dev->dev.type = &input_dev_type; dev->dev.class = &input_class; device_initialize(&dev->dev); mutex_init(&dev->mutex); spin_lock_init(&dev->event_lock); INIT_LIST_HEAD(&dev->h_list); INIT_LIST_HEAD(&dev->node); __module_get(THIS_MODULE); } return dev; } EXPORT_SYMBOL(input_allocate_device); /** * input_free_device - free memory occupied by input_dev structure * @dev: input device to free * * This function should only be used if input_register_device() * was not called yet or if it failed. Once device was registered * use input_unregister_device() and memory will be freed once last * reference to the device is dropped. * * Device should be allocated by input_allocate_device(). * * NOTE: If there are references to the input device then memory * will not be freed until last reference is dropped. */ void input_free_device(struct input_dev *dev) { if (dev) input_put_device(dev); } EXPORT_SYMBOL(input_free_device); /** * input_set_capability - mark device as capable of a certain event * @dev: device that is capable of emitting or accepting event * @type: type of the event (EV_KEY, EV_REL, etc...) * @code: event code * * In addition to setting up corresponding bit in appropriate capability * bitmap the function also adjusts dev->evbit. */ void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code) { switch (type) { case EV_KEY: __set_bit(code, dev->keybit); break; case EV_REL: __set_bit(code, dev->relbit); break; case EV_ABS: __set_bit(code, dev->absbit); break; case EV_MSC: __set_bit(code, dev->mscbit); break; case EV_SW: __set_bit(code, dev->swbit); break; case EV_LED: __set_bit(code, dev->ledbit); break; case EV_SND: __set_bit(code, dev->sndbit); break; case EV_FF: __set_bit(code, dev->ffbit); break; case EV_PWR: /* do nothing */ break; default: printk(KERN_ERR "input_set_capability: unknown type %u (code %u)\n", type, code); dump_stack(); return; } __set_bit(type, dev->evbit); } EXPORT_SYMBOL(input_set_capability); #define INPUT_CLEANSE_BITMASK(dev, type, bits) \ do { \ if (!test_bit(EV_##type, dev->evbit)) \ memset(dev->bits##bit, 0, \ sizeof(dev->bits##bit)); \ } while (0) static void input_cleanse_bitmasks(struct input_dev *dev) { INPUT_CLEANSE_BITMASK(dev, KEY, key); INPUT_CLEANSE_BITMASK(dev, REL, rel); INPUT_CLEANSE_BITMASK(dev, ABS, abs); INPUT_CLEANSE_BITMASK(dev, MSC, msc); INPUT_CLEANSE_BITMASK(dev, LED, led); INPUT_CLEANSE_BITMASK(dev, SND, snd); INPUT_CLEANSE_BITMASK(dev, FF, ff); INPUT_CLEANSE_BITMASK(dev, SW, sw); } /** * input_register_device - register device with input core * @dev: device to be registered * * This function registers device with input core. The device must be * allocated with input_allocate_device() and all it's capabilities * set up before registering. * If function fails the device must be freed with input_free_device(). * Once device has been successfully registered it can be unregistered * with input_unregister_device(); input_free_device() should not be * called in this case. */ int input_register_device(struct input_dev *dev) { static atomic_t input_no = ATOMIC_INIT(0); struct input_handler *handler; const char *path; int error; /* Every input device generates EV_SYN/SYN_REPORT events. */ __set_bit(EV_SYN, dev->evbit); /* KEY_RESERVED is not supposed to be transmitted to userspace. */ __clear_bit(KEY_RESERVED, dev->keybit); /* Make sure that bitmasks not mentioned in dev->evbit are clean. */ input_cleanse_bitmasks(dev); /* * If delay and period are pre-set by the driver, then autorepeating * is handled by the driver itself and we don't do it in input.c. */ init_timer(&dev->timer); if (!dev->rep[REP_DELAY] && !dev->rep[REP_PERIOD]) { dev->timer.data = (long) dev; dev->timer.function = input_repeat_key; dev->rep[REP_DELAY] = 250; dev->rep[REP_PERIOD] = 33; } if (!dev->getkeycode) dev->getkeycode = input_default_getkeycode; if (!dev->setkeycode) dev->setkeycode = input_default_setkeycode; dev_set_name(&dev->dev, "input%ld", (unsigned long) atomic_inc_return(&input_no) - 1); error = device_add(&dev->dev); if (error) return error; path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL); printk(KERN_INFO "input: %s as %s\n", dev->name ? dev->name : "Unspecified device", path ? path : "N/A"); kfree(path); error = mutex_lock_interruptible(&input_mutex); if (error) { device_del(&dev->dev); return error; } list_add_tail(&dev->node, &input_dev_list); list_for_each_entry(handler, &input_handler_list, node) input_attach_handler(dev, handler); input_wakeup_procfs_readers(); mutex_unlock(&input_mutex); return 0; } EXPORT_SYMBOL(input_register_device); /** * input_unregister_device - unregister previously registered device * @dev: device to be unregistered * * This function unregisters an input device. Once device is unregistered * the caller should not try to access it as it may get freed at any moment. */ void input_unregister_device(struct input_dev *dev) { struct input_handle *handle, *next; input_disconnect_device(dev); mutex_lock(&input_mutex); list_for_each_entry_safe(handle, next, &dev->h_list, d_node) handle->handler->disconnect(handle); WARN_ON(!list_empty(&dev->h_list)); del_timer_sync(&dev->timer); list_del_init(&dev->node); input_wakeup_procfs_readers(); mutex_unlock(&input_mutex); device_unregister(&dev->dev); } EXPORT_SYMBOL(input_unregister_device); /** * input_register_handler - register a new input handler * @handler: handler to be registered * * This function registers a new input handler (interface) for input * devices in the system and attaches it to all input devices that * are compatible with the handler. */ int input_register_handler(struct input_handler *handler) { struct input_dev *dev; int retval; retval = mutex_lock_interruptible(&input_mutex); if (retval) return retval; INIT_LIST_HEAD(&handler->h_list); if (handler->fops != NULL) { if (input_table[handler->minor >> 5]) { retval = -EBUSY; goto out; } input_table[handler->minor >> 5] = handler; } list_add_tail(&handler->node, &input_handler_list); list_for_each_entry(dev, &input_dev_list, node) input_attach_handler(dev, handler); input_wakeup_procfs_readers(); out: mutex_unlock(&input_mutex); return retval; } EXPORT_SYMBOL(input_register_handler); /** * input_unregister_handler - unregisters an input handler * @handler: handler to be unregistered * * This function disconnects a handler from its input devices and * removes it from lists of known handlers. */ void input_unregister_handler(struct input_handler *handler) { struct input_handle *handle, *next; mutex_lock(&input_mutex); list_for_each_entry_safe(handle, next, &handler->h_list, h_node) handler->disconnect(handle); WARN_ON(!list_empty(&handler->h_list)); list_del_init(&handler->node); if (handler->fops != NULL) input_table[handler->minor >> 5] = NULL; input_wakeup_procfs_readers(); mutex_unlock(&input_mutex); } EXPORT_SYMBOL(input_unregister_handler); /** * input_handler_for_each_handle - handle iterator * @handler: input handler to iterate * @data: data for the callback * @fn: function to be called for each handle * * Iterate over @bus's list of devices, and call @fn for each, passing * it @data and stop when @fn returns a non-zero value. The function is * using RCU to traverse the list and therefore may be usind in atonic * contexts. The @fn callback is invoked from RCU critical section and * thus must not sleep. */ int input_handler_for_each_handle(struct input_handler *handler, void *data, int (*fn)(struct input_handle *, void *)) { struct input_handle *handle; int retval = 0; rcu_read_lock(); list_for_each_entry_rcu(handle, &handler->h_list, h_node) { retval = fn(handle, data); if (retval) break; } rcu_read_unlock(); return retval; } EXPORT_SYMBOL(input_handler_for_each_handle); /** * input_register_handle - register a new input handle * @handle: handle to register * * This function puts a new input handle onto device's * and handler's lists so that events can flow through * it once it is opened using input_open_device(). * * This function is supposed to be called from handler's * connect() method. */ int input_register_handle(struct input_handle *handle) { struct input_handler *handler = handle->handler; struct input_dev *dev = handle->dev; int error; /* * We take dev->mutex here to prevent race with * input_release_device(). */ error = mutex_lock_interruptible(&dev->mutex); if (error) return error; /* * Filters go to the head of the list, normal handlers * to the tail. */ if (handler->filter) list_add_rcu(&handle->d_node, &dev->h_list); else list_add_tail_rcu(&handle->d_node, &dev->h_list); mutex_unlock(&dev->mutex); /* * Since we are supposed to be called from ->connect() * which is mutually exclusive with ->disconnect() * we can't be racing with input_unregister_handle() * and so separate lock is not needed here. */ list_add_tail_rcu(&handle->h_node, &handler->h_list); if (handler->start) handler->start(handle); return 0; } EXPORT_SYMBOL(input_register_handle); /** * input_unregister_handle - unregister an input handle * @handle: handle to unregister * * This function removes input handle from device's * and handler's lists. * * This function is supposed to be called from handler's * disconnect() method. */ void input_unregister_handle(struct input_handle *handle) { struct input_dev *dev = handle->dev; list_del_rcu(&handle->h_node); /* * Take dev->mutex to prevent race with input_release_device(). */ mutex_lock(&dev->mutex); list_del_rcu(&handle->d_node); mutex_unlock(&dev->mutex); synchronize_rcu(); } EXPORT_SYMBOL(input_unregister_handle); static int input_open_file(struct inode *inode, struct file *file) { struct input_handler *handler; const struct file_operations *old_fops, *new_fops = NULL; int err; err = mutex_lock_interruptible(&input_mutex); if (err) return err; /* No load-on-demand here? */ handler = input_table[iminor(inode) >> 5]; if (handler) new_fops = fops_get(handler->fops); mutex_unlock(&input_mutex); /* * That's _really_ odd. Usually NULL ->open means "nothing special", * not "no device". Oh, well... */ if (!new_fops || !new_fops->open) { fops_put(new_fops); err = -ENODEV; goto out; } old_fops = file->f_op; file->f_op = new_fops; err = new_fops->open(inode, file); if (err) { fops_put(file->f_op); file->f_op = fops_get(old_fops); } fops_put(old_fops); out: return err; } static const struct file_operations input_fops = { .owner = THIS_MODULE, .open = input_open_file, }; static void __init input_init_abs_bypass(void) { const unsigned int *p; for (p = input_abs_bypass_init_data; *p; p++) input_abs_bypass[BIT_WORD(*p)] |= BIT_MASK(*p); } static int __init input_init(void) { int err; input_init_abs_bypass(); err = class_register(&input_class); if (err) { printk(KERN_ERR "input: unable to register input_dev class\n"); return err; } err = input_proc_init(); if (err) goto fail1; err = register_chrdev(INPUT_MAJOR, "input", &input_fops); if (err) { printk(KERN_ERR "input: unable to register char major %d", INPUT_MAJOR); goto fail2; } return 0; fail2: input_proc_exit(); fail1: class_unregister(&input_class); return err; } static void __exit input_exit(void) { input_proc_exit(); unregister_chrdev(INPUT_MAJOR, "input"); class_unregister(&input_class); } subsys_initcall(input_init); module_exit(input_exit);