[PATCH v4 2/9] iio: Add channel for Position Relative

From: Eugen Hristev
Date: Mon Apr 30 2018 - 06:35:12 EST


Add new channel type for relative position on a pad.

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.
+
What: /sys/bus/iio/devices/iio:deviceX/in_anglvel_x_raw
What: /sys/bus/iio/devices/iio:deviceX/in_anglvel_y_raw
What: /sys/bus/iio/devices/iio:deviceX/in_anglvel_z_raw
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 19bdf3d..14bf3d24 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -85,6 +85,7 @@ static const char * const iio_chan_type_name_spec[] = {
[IIO_COUNT] = "count",
[IIO_INDEX] = "index",
[IIO_GRAVITY] = "gravity",
+ [IIO_POSITIONRELATIVE] = "positionrelative",
};

static const char * const iio_modifier_names[] = {
diff --git a/include/uapi/linux/iio/types.h b/include/uapi/linux/iio/types.h
index 4213cdf..033c7d2 100644
--- a/include/uapi/linux/iio/types.h
+++ b/include/uapi/linux/iio/types.h
@@ -44,6 +44,7 @@ enum iio_chan_type {
IIO_COUNT,
IIO_INDEX,
IIO_GRAVITY,
+ IIO_POSITIONRELATIVE,
};

enum iio_modifier {
diff --git a/tools/iio/iio_event_monitor.c b/tools/iio/iio_event_monitor.c
index b61245e..148f69d 100644
--- a/tools/iio/iio_event_monitor.c
+++ b/tools/iio/iio_event_monitor.c
@@ -58,6 +58,7 @@ static const char * const iio_chan_type_name_spec[] = {
[IIO_PH] = "ph",
[IIO_UVINDEX] = "uvindex",
[IIO_GRAVITY] = "gravity",
+ [IIO_POSITIONRELATIVE] = "positionrelative",
};

static const char * const iio_ev_type_text[] = {
@@ -151,6 +152,7 @@ static bool event_is_known(struct iio_event_data *event)
case IIO_PH:
case IIO_UVINDEX:
case IIO_GRAVITY:
+ case IIO_POSITIONRELATIVE:
break;
default:
return false;
--
2.7.4