diff options
| author | Hans de Goede | 2022-02-28 22:58:28 -0800 |
|---|---|---|
| committer | Dmitry Torokhov | 2022-02-28 23:26:27 -0800 |
| commit | cb66b9ba5cdacab5592bce31a4083fc4ac172ea5 (patch) | |
| tree | 7304866999301a410f380c60ef43631c40597fe4 /drivers/input | |
| parent | 3f9ed5c2fe36794c1b11697bbbc6c8ec82a7d3dc (diff) | |
Input: add input_copy_abs() function
Add a new helper function to copy absinfo from one input_dev to
another input_dev.
This is useful to e.g. setup a pen/stylus input-device for combined
touchscreen/pen hardware where the pen uses the same coordinates as
the touchscreen.
Suggested-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220131143539.109142-2-hdegoede@redhat.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers/input')
| -rw-r--r-- | drivers/input/input.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/input/input.c b/drivers/input/input.c index 3a5156012fb8..4456e82d370b 100644 --- a/drivers/input/input.c +++ b/drivers/input/input.c @@ -526,6 +526,42 @@ void input_set_abs_params(struct input_dev *dev, unsigned int axis, } EXPORT_SYMBOL(input_set_abs_params); +/** + * input_copy_abs - Copy absinfo from one input_dev to another + * @dst: Destination input device to copy the abs settings to + * @dst_axis: ABS_* value selecting the destination axis + * @src: Source input device to copy the abs settings from + * @src_axis: ABS_* value selecting the source axis + * + * Set absinfo for the selected destination axis by copying it from + * the specified source input device's source axis. + * This is useful to e.g. setup a pen/stylus input-device for combined + * touchscreen/pen hardware where the pen uses the same coordinates as + * the touchscreen. + */ +void input_copy_abs(struct input_dev *dst, unsigned int dst_axis, + const struct input_dev *src, unsigned int src_axis) +{ + /* src must have EV_ABS and src_axis set */ + if (WARN_ON(!(test_bit(EV_ABS, src->evbit) && + test_bit(src_axis, src->absbit)))) + return; + + /* + * input_alloc_absinfo() may have failed for the source. Our caller is + * expected to catch this when registering the input devices, which may + * happen after the input_copy_abs() call. + */ + if (!src->absinfo) + return; + + input_set_capability(dst, EV_ABS, dst_axis); + if (!dst->absinfo) + return; + + dst->absinfo[dst_axis] = src->absinfo[src_axis]; +} +EXPORT_SYMBOL(input_copy_abs); /** * input_grab_device - grabs device for exclusive use |