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| author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2010-11-29 23:33:04 -0800 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2010-11-30 23:11:57 -0800 |
| commit | 86b17f76f462db460d6d916e105a4c44cb353e36 (patch) | |
| tree | b83c3f03f91867260143126ed75592353bfefaa8 /include/linux/input.h | |
| parent | 0417596f66dd6621f4fd46563c7c56a95311dbe8 (diff) | |
| download | lwn-86b17f76f462db460d6d916e105a4c44cb353e36.tar.gz lwn-86b17f76f462db460d6d916e105a4c44cb353e36.zip | |
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/linux/input.h')
| -rw-r--r-- | include/linux/input.h | 21 |
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 |