struct input_dev
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## Name

struct input_dev — represents an input device

## Synopsis

    struct input_dev {
      const char * name;
      const char * phys;
      const char * uniq;
      struct input_id id;
      unsigned long evbit[BITS_TO_LONGS(EV_CNT)];
      unsigned long keybit[BITS_TO_LONGS(KEY_CNT)];
      unsigned long relbit[BITS_TO_LONGS(REL_CNT)];
      unsigned long absbit[BITS_TO_LONGS(ABS_CNT)];
      unsigned long mscbit[BITS_TO_LONGS(MSC_CNT)];
      unsigned long ledbit[BITS_TO_LONGS(LED_CNT)];
      unsigned long sndbit[BITS_TO_LONGS(SND_CNT)];
      unsigned long ffbit[BITS_TO_LONGS(FF_CNT)];
      unsigned long swbit[BITS_TO_LONGS(SW_CNT)];
      unsigned int keycodemax;
      unsigned int keycodesize;
      void * keycode;
      int (* setkeycode) (struct input_dev *dev, int scancode, int keycode);
      int (* getkeycode) (struct input_dev *dev, int scancode, int *keycode);
      struct ff_device * ff;
      unsigned int repeat_key;
      struct timer_list timer;
      int sync;
      int abs[ABS_MAX + 1];
      int rep[REP_MAX + 1];
      unsigned long key[BITS_TO_LONGS(KEY_CNT)];
      unsigned long led[BITS_TO_LONGS(LED_CNT)];
      unsigned long snd[BITS_TO_LONGS(SND_CNT)];
      unsigned long sw[BITS_TO_LONGS(SW_CNT)];
      int absmax[ABS_MAX + 1];
      int absmin[ABS_MAX + 1];
      int absfuzz[ABS_MAX + 1];
      int absflat[ABS_MAX + 1];
      int (* open) (struct input_dev *dev);
      void (* close) (struct input_dev *dev);
      int (* flush) (struct input_dev *dev, struct file *file);
      int (* event) (struct input_dev *dev, unsigned int type, unsigned int code, int value);
      struct input_handle * grab;
      spinlock_t event_lock;
      struct mutex mutex;
      unsigned int users;
      int going_away;
      struct device dev;
      struct list_head h_list;
      struct list_head node;
    };

## Members

name

  name of the device

phys

  physical path to the device in the system hierarchy

uniq

  unique identification code for the device (if device has it)

id

  id of the device (struct input_id)

evbit[BITS_TO_LONGS(EV_CNT)]

  bitmap of types of events supported by the device (EV_KEY, EV_REL, etc.)

keybit[BITS_TO_LONGS(KEY_CNT)]

  bitmap of keys/buttons this device has

relbit[BITS_TO_LONGS(REL_CNT)]

  bitmap of relative axes for the device

absbit[BITS_TO_LONGS(ABS_CNT)]

  bitmap of absolute axes for the device

mscbit[BITS_TO_LONGS(MSC_CNT)]

  bitmap of miscellaneous events supported by the device

ledbit[BITS_TO_LONGS(LED_CNT)]

  bitmap of leds present on the device

sndbit[BITS_TO_LONGS(SND_CNT)]

  bitmap of sound effects supported by the device

ffbit[BITS_TO_LONGS(FF_CNT)]

  bitmap of force feedback effects supported by the device

swbit[BITS_TO_LONGS(SW_CNT)]

  bitmap of switches present on the device

keycodemax

  size of keycode table

keycodesize

  size of elements in keycode table

keycode

  map of scancodes to keycodes for this device

setkeycode

  optional method to alter current keymap, used to implement sparse keymaps. If not supplied default mechanism will be used

getkeycode

  optional method to retrieve current keymap. If not supplied default mechanism will be used

ff

  force feedback structure associated with the device if device supports force feedback effects

repeat_key

  stores key code of the last key pressed; used to implement software autorepeat

timer

  timer for software autorepeat

sync

  set to 1 when there were no new events since last EV_SYNC

abs[ABS_MAX + 1]

  current values for reports from absolute axes

rep[REP_MAX + 1]

  current values for autorepeat parameters (delay, rate)

key[BITS_TO_LONGS(KEY_CNT)]

  reflects current state of device's keys/buttons

led[BITS_TO_LONGS(LED_CNT)]

  reflects current state of device's LEDs

snd[BITS_TO_LONGS(SND_CNT)]

  reflects current state of sound effects

sw[BITS_TO_LONGS(SW_CNT)]

  reflects current state of device's switches

absmax[ABS_MAX + 1]

  maximum values for events coming from absolute axes

absmin[ABS_MAX + 1]

  minimum values for events coming from absolute axes

absfuzz[ABS_MAX + 1]

  describes noisiness for axes

absflat[ABS_MAX + 1]

  size of the center flat position (used by joydev)

open

  this method is called when the very first user calls `input_open_device`. The driver must prepare the device to start generating events (start polling thread, request an IRQ, submit URB, etc.)

close

  this method is called when the very last user calls `input_close_device`.

flush

  purges the device. Most commonly used to get rid of force feedback effects loaded into the device when disconnecting from it

event

  event handler for events sent _to_ the device, like EV_LED or EV_SND. The device is expected to carry out the requested action (turn on a LED, play sound, etc.) The call is protected by `event_lock` and must not sleep

grab

  input handle that currently has the device grabbed (via EVIOCGRAB ioctl). When a handle grabs a device it becomes sole recipient for all input events coming from the device

event_lock

  this spinlock is is taken when input core receives and processes a new event for the device (in `input_event`). Code that accesses and/or modifies parameters of a device (such as keymap or absmin, absmax, absfuzz, etc.) after device has been registered with input core must take this lock.

mutex

  serializes calls to `open`, `close` and `flush` methods

users

  stores number of users (input handlers) that opened this device. It is used by `input_open_device` and `input_close_device` to make sure that dev->`open` is only called when the first user opens device and dev->`close` is called when the very last user closes the device

going_away

  marks devices that are in a middle of unregistering and causes input_open_device*() fail with -ENODEV.

dev

  driver model's view of this device

h_list

  list of input handles associated with the device. When accessing the list dev->mutex must be held

node

  used to place the device onto input_dev_list

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