On Tue, 10 Apr 2018 11:57:49 +0300Hello Jonathan,
Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx> wrote:
Add new channel type for relative position on a pad.I know the milli percent comes form the humidity equivalent, but I wonder
These type of analog sensor offers the position of a pen
on a touchpad, and is represented as a voltage, which can be
converted to a position on X and Y axis on the pad.
The channel will hand the relative position on the pad in both directions.
The channel can then be consumed by a touchscreen driver or
read as-is for a raw indication of the touchpen on a touchpad.
Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
---
Changes in v2:
- modified channel name to relative position as suggested.
- modified kernel version to 4.18 (presumable)
Documentation/ABI/testing/sysfs-bus-iio | 12 ++++++++++++
drivers/iio/industrialio-core.c | 1 +
include/uapi/linux/iio/types.h | 1 +
tools/iio/iio_event_monitor.c | 2 ++
4 files changed, 16 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index 6a5f34b..42a9287 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -190,6 +190,18 @@ Description:
but should match other such assignments on device).
Units after application of scale and offset are m/s^2.
+What: /sys/bus/iio/devices/iio:deviceX/in_positionrelative_x_raw
+What: /sys/bus/iio/devices/iio:deviceX/in_positionrelative_y_raw
+KernelVersion: 4.18
+Contact: linux-iio@xxxxxxxxxxxxxxx
+Description:
+ Relative position in direction x or y on a pad (may be
+ arbitrarily assigned but should match other such assignments on
+ device).
+ Units after application of scale and offset are milli percents
+ from the pad's size in both directions. Should be calibrated by
+ the consumer.
if we are right to follow that. 10^-5 is a pretty random base unit (though
I got argued into it being a standard choice for humidity sensors IIRC...
What do people think? We could go with 1 for full range or just percent perhaps?
I'm not that fussed about staying consistent with humidity - we are unlikely
to end up with sensors doing both anytime soon so there shouldn't be
any confusion...
Jonathan
+
[...]