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From:   Ramona Bolboaca <ramona.bolboaca@analog.com>
To:     <jic23@kernel.org>, <nuno.sa@analog.com>,
        <linux-iio@vger.kernel.org>, <linux-kernel@vger.kernel.org>
CC:     Ramona Bolboaca <ramona.bolboaca@analog.com>
Subject: [PATCH v4 1/3] iio: Add IIO_DELTA_ANGL channel type
Date:   Mon, 7 Aug 2023 14:12:25 +0300
Message-ID: <20230807111227.374371-2-ramona.bolboaca@analog.com>
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The delta angle is defined as a piece-wise integration of angular
velocity data. The delta angle represents the amount of
angular displacement between two consecutive measurements and it
is measured in radians.

In order to track the total angular displacement during a desired
period of time, simply sum-up the delta angle samples acquired
during that time.

IIO currently does not offer a suitable channel type for this
type of measurements hence this patch adds it.

Signed-off-by: Ramona Bolboaca <ramona.bolboaca@analog.com>
---
 Documentation/ABI/testing/sysfs-bus-iio | 14 ++++++++++++++
 drivers/iio/industrialio-core.c         |  1 +
 include/uapi/linux/iio/types.h          |  1 +
 tools/iio/iio_event_monitor.c           |  2 ++
 4 files changed, 18 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index a2854dc9a839..32675fa7dc6f 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -279,6 +279,20 @@ 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_deltaangl_x_raw
+What:		/sys/bus/iio/devices/iio:deviceX/in_deltaangl_y_raw
+What:		/sys/bus/iio/devices/iio:deviceX/in_deltaangl_z_raw
+KernelVersion:	6.5
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Angular displacement between two consecutive samples on x, y or
+		z (may be arbitrarily assigned but should match other such
+		assignments on device).
+		In order to compute the total angular displacement during a
+		desired period of time, the application should sum-up the delta
+		angle samples acquired during that time.
+		Units after application of scale and offset are radians.
+
 What:		/sys/bus/iio/devices/iio:deviceX/in_angl_raw
 What:		/sys/bus/iio/devices/iio:deviceX/in_anglY_raw
 KernelVersion:	4.17
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index a92b8b6ad647..2e2fd0be2504 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -89,6 +89,7 @@ static const char * const iio_chan_type_name_spec[] = {
 	[IIO_POSITIONRELATIVE]  = "positionrelative",
 	[IIO_PHASE] = "phase",
 	[IIO_MASSCONCENTRATION] = "massconcentration",
+	[IIO_DELTA_ANGL] = "deltaangl",
 };
 
 static const char * const iio_modifier_names[] = {
diff --git a/include/uapi/linux/iio/types.h b/include/uapi/linux/iio/types.h
index c79f2f046a0b..55666a17d311 100644
--- a/include/uapi/linux/iio/types.h
+++ b/include/uapi/linux/iio/types.h
@@ -47,6 +47,7 @@ enum iio_chan_type {
 	IIO_POSITIONRELATIVE,
 	IIO_PHASE,
 	IIO_MASSCONCENTRATION,
+	IIO_DELTA_ANGL,
 };
 
 enum iio_modifier {
diff --git a/tools/iio/iio_event_monitor.c b/tools/iio/iio_event_monitor.c
index 0a5c2bb60030..3505450060e6 100644
--- a/tools/iio/iio_event_monitor.c
+++ b/tools/iio/iio_event_monitor.c
@@ -59,6 +59,7 @@ static const char * const iio_chan_type_name_spec[] = {
 	[IIO_POSITIONRELATIVE] = "positionrelative",
 	[IIO_PHASE] = "phase",
 	[IIO_MASSCONCENTRATION] = "massconcentration",
+	[IIO_DELTA_ANGL] = "deltaangl",
 };
 
 static const char * const iio_ev_type_text[] = {
@@ -173,6 +174,7 @@ static bool event_is_known(struct iio_event_data *event)
 	case IIO_POSITIONRELATIVE:
 	case IIO_PHASE:
 	case IIO_MASSCONCENTRATION:
+	case IIO_DELTA_ANGL:
 		break;
 	default:
 		return false;
-- 
2.34.1