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authorHenrik Rydberg <rydberg@euromail.se>2012-09-01 09:27:20 +0200
committerHenrik Rydberg <rydberg@euromail.se>2012-09-19 19:50:19 +0200
commit17a465a7f2d6ce31738a3a76591afeab165f185a (patch)
treeb10a27eb43a6eb0aee31aa851c00936ec3edcc17 /drivers/input
parentInput: MT - Add in-kernel tracking (diff)
downloadlinux-dev-17a465a7f2d6ce31738a3a76591afeab165f185a.tar.xz
linux-dev-17a465a7f2d6ce31738a3a76591afeab165f185a.zip
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>
Diffstat (limited to 'drivers/input')
-rw-r--r--drivers/input/input-mt.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
index caff298832a4..44f5a67aaa69 100644
--- a/drivers/input/input-mt.c
+++ b/drivers/input/input-mt.c
@@ -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);