[PATCH v4 2/7] iio: core: Introduce IIO_ACTIVITY channel

From: Daniel Baluta
Date: Mon Nov 10 2014 - 07:44:30 EST


This channel will be used for exposing information about
activity composite sensors. Activities supported so far:
* running
* jogging
* walking
* still

THRESHOLD event is used to signal a change in the activity
state.

We associate a confidence interval for each activity expressed
as a percentage from 0 to 100.
* 0, means the sensor IS NOT reporting that activity.
* 100, means the sensor IS reporting that activity.

Users of this interface have two possible means to gather
information about the ongoing activities.

1. Event based, via event file descriptor
* sensor may report an event when ENTERING an activity or LEAVING
an activity based on a threshold value.
* drivers will wake up applications waiting data on the event fd

2. Polling, by reading the sysfs associated attribute files:
* /sys/bus/iio/devices/iio:device0/in_activity_running_input
expressed as percentage confidence value from 0 to 100.

This will offer an interface for Android significant motion
composite sensor defined here:
http://source.android.com/devices/sensors/composite_sensors.html

Activities listed above are supported by Freescale's MMA9553 sensor:
http://freescale.com/files/sensors/doc/ref_manual/MMA9553LSWRM.pdf

Signed-off-by: Irina Tirdea <irina.tirdea@xxxxxxxxx>
Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxxxx>
---
Documentation/ABI/testing/sysfs-bus-iio | 44 +++++++++++++++++++++++++++++++++
drivers/iio/industrialio-core.c | 5 ++++
include/linux/iio/types.h | 7 +++++-
3 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index 117521d..7bf49ad 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -790,6 +790,40 @@ Description:
met before an event is generated. If direction is not
specified then this period applies to both directions.

+What: /sys/.../events/in_activity_still_thresh_rising_en
+What: /sys/.../events/in_activity_still_thresh_falling_en
+What: /sys/.../events/in_activity_walking_thresh_rising_en
+What: /sys/.../events/in_activity_walking_thresh_falling_en
+What: /sys/.../events/in_activity_jogging_thresh_rising_en
+What: /sys/.../events/in_activity_jogging_thresh_falling_en
+What: /sys/.../events/in_activity_running_thresh_rising_en
+What: /sys/.../events/in_activity_running_thresh_falling_en
+KernelVersion: 3.19
+Contact: linux-iio@xxxxxxxxxxxxxxx
+Description:
+ Enables or disables activitity events. Depending on direction
+ an event is generated when sensor ENTERS or LEAVES a given state.
+
+What: /sys/.../events/in_activity_still_thresh_rising_value
+What: /sys/.../events/in_activity_still_thresh_falling_value
+What: /sys/.../events/in_activity_walking_thresh_rising_value
+What: /sys/.../events/in_activity_walking_thresh_falling_value
+What: /sys/.../events/in_activity_jogging_thresh_rising_value
+What: /sys/.../events/in_activity_jogging_thresh_falling_value
+What: /sys/.../events/in_activity_running_thresh_rising_value
+What: /sys/.../events/in_activity_running_thresh_falling_value
+KernelVersion: 3.19
+Contact: linux-iio@xxxxxxxxxxxxxxx
+Description:
+ Confidence value (in units as percentage) to be used
+ for deciding when an event should be generated. E.g for
+ running: If the confidence value reported by the sensor
+ is greater than in_activity_running_thresh_rising_value
+ then the sensor ENTERS running state. Conversely, if the
+ confidence value reported by the sensor is lower than
+ in_activity_running_thresh_falling_value then the sensor
+ is LEAVING running state.
+
What: /sys/.../iio:deviceX/events/in_accel_mag_en
What: /sys/.../iio:deviceX/events/in_accel_mag_rising_en
What: /sys/.../iio:deviceX/events/in_accel_mag_falling_en
@@ -956,6 +990,16 @@ Description:
and the relevant _type attributes to establish the data storage
format.

+What: /sys/.../iio:deviceX/in_activity_still_input
+What: /sys/.../iio:deviceX/in_activity_walking_input
+What: /sys/.../iio:deviceX/in_activity_jogging_input
+What: /sys/.../iio:deviceX/in_activity_running_input
+KernelVersion: 3.19
+Contact: linux-iio@xxxxxxxxxxxxxxx
+Description:
+ This attribute is used to read the confidence for an activity
+ expressed in units as percentage.
+
What: /sys/.../iio:deviceX/in_anglvel_z_quadrature_correction_raw
KernelVersion: 2.6.38
Contact: linux-iio@xxxxxxxxxxxxxxx
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index af3e76d..e453ef9 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -70,6 +70,7 @@ static const char * const iio_chan_type_name_spec[] = {
[IIO_CCT] = "cct",
[IIO_PRESSURE] = "pressure",
[IIO_HUMIDITYRELATIVE] = "humidityrelative",
+ [IIO_ACTIVITY] = "activity",
};

static const char * const iio_modifier_names[] = {
@@ -91,6 +92,10 @@ static const char * const iio_modifier_names[] = {
[IIO_MOD_NORTH_TRUE] = "from_north_true",
[IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
[IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
+ [IIO_MOD_RUNNING] = "running",
+ [IIO_MOD_JOGGING] = "jogging",
+ [IIO_MOD_WALKING] = "walking",
+ [IIO_MOD_STILL] = "still",
};

/* relies on pairs of these shared then separate */
diff --git a/include/linux/iio/types.h b/include/linux/iio/types.h
index 4a2af8a..b3a241d 100644
--- a/include/linux/iio/types.h
+++ b/include/linux/iio/types.h
@@ -30,6 +30,7 @@ enum iio_chan_type {
IIO_CCT,
IIO_PRESSURE,
IIO_HUMIDITYRELATIVE,
+ IIO_ACTIVITY,
};

enum iio_modifier {
@@ -59,7 +60,11 @@ enum iio_modifier {
IIO_MOD_NORTH_MAGN,
IIO_MOD_NORTH_TRUE,
IIO_MOD_NORTH_MAGN_TILT_COMP,
- IIO_MOD_NORTH_TRUE_TILT_COMP
+ IIO_MOD_NORTH_TRUE_TILT_COMP,
+ IIO_MOD_RUNNING,
+ IIO_MOD_JOGGING,
+ IIO_MOD_WALKING,
+ IIO_MOD_STILL,
};

enum iio_event_type {
--
1.9.1

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