From 1a8f324aa1f2237caef1c6633734785bbdcffeed Mon Sep 17 00:00:00 2001
From: William Breathitt Gray <vilhelm.gray@gmail.com>
Date: Wed, 28 Sep 2016 13:59:49 -0400
Subject: [PATCH] iio: Implement counter channel type and info constants
Quadrature encoders, such as rotary encoders and linear encoders, are
devices which are capable of encoding the relative position and
direction of motion of a shaft. This patch introduces several IIO
constants for supporting quadrature encoder counter devices.
IIO_COUNT: Current count (main data provided by the counter device)
IIO_INDEX: Counter device index value
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
---
Documentation/ABI/testing/sysfs-bus-iio | 18 ++++++++++++++++++
drivers/iio/industrialio-core.c | 2 ++
include/uapi/linux/iio/types.h | 2 ++
3 files changed, 22 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index fee35c00cc4ed..b8f220f978dd3 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -329,6 +329,7 @@ What: /sys/bus/iio/devices/iio:deviceX/in_pressure_scale
What: /sys/bus/iio/devices/iio:deviceX/in_humidityrelative_scale
What: /sys/bus/iio/devices/iio:deviceX/in_velocity_sqrt(x^2+y^2+z^2)_scale
What: /sys/bus/iio/devices/iio:deviceX/in_illuminance_scale
+What: /sys/bus/iio/devices/iio:deviceX/in_countY_scale
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
@@ -1579,3 +1580,20 @@ Contact: linux-iio@vger.kernel.org
Description:
Raw (unscaled no offset etc.) electric conductivity reading that
can be processed to siemens per meter.
+
+What: /sys/bus/iio/devices/iio:deviceX/in_countY_raw
+KernelVersion: 4.9
+Contact: linux-iio@vger.kernel.org
+Description:
+ Raw counter device counts from channel Y. For quadrature
+ counters, multiplication by an available [Y]_scale results in
+ the counts of a single quadrature signal phase from channel Y.
+
+What: /sys/bus/iio/devices/iio:deviceX/in_indexY_raw
+KernelVersion: 4.9
+Contact: linux-iio@vger.kernel.org
+Description:
+ Raw counter device index value from channel Y. This attribute
+ provides an absolute positional reference (e.g. a pulse once per
+ revolution) which may be used to home positional systems as
+ required.
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index fc340ed3dca1c..649725bc15c1a 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -81,6 +81,8 @@ static const char * const iio_chan_type_name_spec[] = {
[IIO_PH] = "ph",
[IIO_UVINDEX] = "uvindex",
[IIO_ELECTRICALCONDUCTIVITY] = "electricalconductivity",
+ [IIO_COUNT] = "count",
+ [IIO_INDEX] = "index",
};
static const char * const iio_modifier_names[] = {
diff --git a/include/uapi/linux/iio/types.h b/include/uapi/linux/iio/types.h
index 22e5e589a2747..e54d14a7f876b 100644
--- a/include/uapi/linux/iio/types.h
+++ b/include/uapi/linux/iio/types.h
@@ -40,6 +40,8 @@ enum iio_chan_type {
IIO_PH,
IIO_UVINDEX,
IIO_ELECTRICALCONDUCTIVITY,
+ IIO_COUNT,
+ IIO_INDEX,
};
enum iio_modifier {
--
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