Documentation/input/input-programming.rst

34 		    return -EBUSY;
40 		    error = -ENOMEM;
44 	    button_dev->evbit[0] = BIT_MASK(EV_KEY);
45 	    button_dev->keybit[BIT_WORD(BTN_0)] = BIT_MASK(BTN_0);
83 parts of the input systems what it is - what events can be generated or
88 	set_bit(EV_KEY, button_dev->evbit);
89 	set_bit(BTN_0, button_dev->keybit);
126 dev->open() and dev->close()
140 		    return -EBUSY;
154 	    button_dev->open = button_open;
155 	    button_dev->close = button_close;
160 makes sure that dev->open() is called only when the first user connects
161 to the device and that dev->close() is called when the very last user
164 The open() callback should return a 0 in case of success or any non-zero value
171 maintaining relationships with input handlers - either already existing
184 driver to save power. Either by directly powering down the device or by
185 releasing the runtime-PM reference it got in open() when the driver is using
186 runtime-PM.
195 inhibiting, sleeping and being a wakeup source is driver-specific.
197 Taking the analogy with the network devices - bringing a network interface down
202 is not aware of input-specific inhibit (nor should it be).  Composite devices
203 containing several interfaces can be inhibited on a per-interface basis and e.g.
221 See uapi/linux/input-event-codes.h for the allowable values of code (from 0 to
222 KEY_MAX). Value is interpreted as a truth value, i.e. any non-zero value means
231 events are namely for joysticks and digitizers - devices that do work in an
239 function. Events are generated only for non-zero values.
258 max values), with noise in the data up to +- 4, and with a center flat
270 	BITS_TO_LONGS(x) - returns the length of a bitfield array in longs for
272 	BIT_WORD(x)	 - returns the index in the array in longs for bit x
273 	BIT_MASK(x)	 - returns the index in a long for bit x
278 The dev->name should be set before registering the input device by the input
280 user friendly name of the device.
306 dev->getkeycode() and dev->setkeycode()
319 autorepeat for your device, just set EV_REP in dev->evbit. All will be
327 - EV_LED - used for the keyboard LEDs.
328 - EV_SND - used for keyboard beeps.
331 direction - from the system to the input device driver. If your input device
335     button_dev->event = button_event;
344 	    return -1;