Input: MT - Get slot by key

Some devices use an internal key for tracking which cannot be directly
mapped to slots. This patch provides a key-to-slot mapping, which can
be used by drivers of such devices.

Reviewed-and-tested-by: Benjamin Tissoires <benjamin.tissoires@enac.fr>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
This commit is contained in:
Henrik Rydberg 2012-09-01 09:27:20 +02:00
parent 7c1a87897c
commit 17a465a7f2
2 changed files with 36 additions and 0 deletions

View File

@ -383,3 +383,35 @@ int input_mt_assign_slots(struct input_dev *dev, int *slots,
return 0;
}
EXPORT_SYMBOL(input_mt_assign_slots);
/**
* input_mt_get_slot_by_key() - return slot matching key
* @dev: input device with allocated MT slots
* @key: the key of the sought slot
*
* Returns the slot of the given key, if it exists, otherwise
* set the key on the first unused slot and return.
*
* If no available slot can be found, -1 is returned.
*/
int input_mt_get_slot_by_key(struct input_dev *dev, int key)
{
struct input_mt *mt = dev->mt;
struct input_mt_slot *s;
if (!mt)
return -1;
for (s = mt->slots; s != mt->slots + mt->num_slots; s++)
if (input_mt_is_active(s) && s->key == key)
return s - mt->slots;
for (s = mt->slots; s != mt->slots + mt->num_slots; s++)
if (!input_mt_is_active(s)) {
s->key = key;
return s - mt->slots;
}
return -1;
}
EXPORT_SYMBOL(input_mt_get_slot_by_key);

View File

@ -24,10 +24,12 @@
* struct input_mt_slot - represents the state of an input MT slot
* @abs: holds current values of ABS_MT axes for this slot
* @frame: last frame at which input_mt_report_slot_state() was called
* @key: optional driver designation of this slot
*/
struct input_mt_slot {
int abs[ABS_MT_LAST - ABS_MT_FIRST + 1];
unsigned int frame;
unsigned int key;
};
/**
@ -111,4 +113,6 @@ struct input_mt_pos {
int input_mt_assign_slots(struct input_dev *dev, int *slots,
const struct input_mt_pos *pos, int num_pos);
int input_mt_get_slot_by_key(struct input_dev *dev, int key);
#endif