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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2010-11-30 10:33:04 +0300
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2010-12-01 10:11:57 +0300
commit86b17f76f462db460d6d916e105a4c44cb353e36 (patch)
treeb83c3f03f91867260143126ed75592353bfefaa8 /include
parent0417596f66dd6621f4fd46563c7c56a95311dbe8 (diff)
downloadlinux-86b17f76f462db460d6d916e105a4c44cb353e36.tar.xz
Input: document struct input_absinfo
Add documentation for struct input_absinfo that is used in EVIOCGABS and EVIOCSABS ioctl and specify units of measure used for reporting resolution for an axis. Acked-by: Henrik Rydberg <rydberg@euromail.se> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Diffstat (limited to 'include')
-rw-r--r--include/linux/input.h21
1 files changed, 20 insertions, 1 deletions
diff --git a/include/linux/input.h b/include/linux/input.h
index a50046f15372..a8af21d42bc1 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -47,6 +47,25 @@ struct input_id {
__u16 version;
};
+/**
+ * struct input_absinfo - used by EVIOCGABS/EVIOCSABS ioctls
+ * @value: latest reported value for the axis.
+ * @minimum: specifies minimum value for the axis.
+ * @maximum: specifies maximum value for the axis.
+ * @fuzz: specifies fuzz value that is used to filter noise from
+ * the event stream.
+ * @flat: values that are within this value will be discarded by
+ * joydev interface and reported as 0 instead.
+ * @resolution: specifies resolution for the values reported for
+ * the axis.
+ *
+ * Note that input core does not clamp reported values to the
+ * [minimum, maximum] limits, such task is left to userspace.
+ *
+ * Resolution for main axes (ABS_X, ABS_Y, ABS_Z) is reported in
+ * units per millimeter (units/mm), resolution for rotational axes
+ * (ABS_RX, ABS_RY, ABS_RZ) is reported in units per radian.
+ */
struct input_absinfo {
__s32 value;
__s32 minimum;
@@ -1134,7 +1153,7 @@ struct input_mt_slot {
* of tracked contacts
* @mtsize: number of MT slots the device uses
* @slot: MT slot currently being transmitted
- * @absinfo: array of &struct absinfo elements holding information
+ * @absinfo: array of &struct input_absinfo elements holding information
* about absolute axes (current value, min, max, flat, fuzz,
* resolution)
* @key: reflects current state of device's keys/buttons