Commit 189c3c49 authored by Jeff LaBundy's avatar Jeff LaBundy Committed by Lee Jones

iio: position: Add support for Azoteq IQS624/625 angle sensors

This patch adds support for the Azoteq IQS624 and IQS625 angular position
sensors, capable of reporting the angle of a rotating shaft down to 1 and
10 degrees of accuracy, respectively.

This patch also introduces a home for linear and angular position sensors.
Unlike resolvers, they are typically contactless and use the Hall effect.
Signed-off-by: default avatarJeff LaBundy <jeff@labundy.com>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
parent b081b738
...@@ -88,6 +88,7 @@ source "drivers/iio/orientation/Kconfig" ...@@ -88,6 +88,7 @@ source "drivers/iio/orientation/Kconfig"
if IIO_TRIGGER if IIO_TRIGGER
source "drivers/iio/trigger/Kconfig" source "drivers/iio/trigger/Kconfig"
endif #IIO_TRIGGER endif #IIO_TRIGGER
source "drivers/iio/position/Kconfig"
source "drivers/iio/potentiometer/Kconfig" source "drivers/iio/potentiometer/Kconfig"
source "drivers/iio/potentiostat/Kconfig" source "drivers/iio/potentiostat/Kconfig"
source "drivers/iio/pressure/Kconfig" source "drivers/iio/pressure/Kconfig"
......
...@@ -31,6 +31,7 @@ obj-y += light/ ...@@ -31,6 +31,7 @@ obj-y += light/
obj-y += magnetometer/ obj-y += magnetometer/
obj-y += multiplexer/ obj-y += multiplexer/
obj-y += orientation/ obj-y += orientation/
obj-y += position/
obj-y += potentiometer/ obj-y += potentiometer/
obj-y += potentiostat/ obj-y += potentiostat/
obj-y += pressure/ obj-y += pressure/
......
# SPDX-License-Identifier: GPL-2.0-only
#
# Linear and angular position sensors
#
# When adding new entries keep the list in alphabetical order
menu "Linear and angular position sensors"
config IQS624_POS
tristate "Azoteq IQS624/625 angular position sensors"
depends on MFD_IQS62X || COMPILE_TEST
help
Say Y here if you want to build support for the Azoteq IQS624
and IQS625 angular position sensors.
To compile this driver as a module, choose M here: the module
will be called iqs624-pos.
endmenu
#
# Makefile for IIO linear and angular position sensors
#
# When adding new entries keep the list in alphabetical order
obj-$(CONFIG_IQS624_POS) += iqs624-pos.o
// SPDX-License-Identifier: GPL-2.0+
/*
* Azoteq IQS624/625 Angular Position Sensors
*
* Copyright (C) 2019 Jeff LaBundy <jeff@labundy.com>
*/
#include <linux/device.h>
#include <linux/iio/events.h>
#include <linux/iio/iio.h>
#include <linux/kernel.h>
#include <linux/mfd/iqs62x.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#define IQS624_POS_DEG_OUT 0x16
#define IQS624_POS_SCALE1 (314159 / 180)
#define IQS624_POS_SCALE2 100000
struct iqs624_pos_private {
struct iqs62x_core *iqs62x;
struct notifier_block notifier;
struct mutex lock;
bool angle_en;
u16 angle;
};
static int iqs624_pos_angle_en(struct iqs62x_core *iqs62x, bool angle_en)
{
unsigned int event_mask = IQS624_HALL_UI_WHL_EVENT;
/*
* The IQS625 reports angular position in the form of coarse intervals,
* so only interval change events are unmasked. Conversely, the IQS624
* reports angular position down to one degree of resolution, so wheel
* movement events are unmasked instead.
*/
if (iqs62x->dev_desc->prod_num == IQS625_PROD_NUM)
event_mask = IQS624_HALL_UI_INT_EVENT;
return regmap_update_bits(iqs62x->regmap, IQS624_HALL_UI, event_mask,
angle_en ? 0 : 0xFF);
}
static int iqs624_pos_notifier(struct notifier_block *notifier,
unsigned long event_flags, void *context)
{
struct iqs62x_event_data *event_data = context;
struct iqs624_pos_private *iqs624_pos;
struct iqs62x_core *iqs62x;
struct iio_dev *indio_dev;
u16 angle = event_data->ui_data;
s64 timestamp;
int ret;
iqs624_pos = container_of(notifier, struct iqs624_pos_private,
notifier);
indio_dev = iio_priv_to_dev(iqs624_pos);
timestamp = iio_get_time_ns(indio_dev);
iqs62x = iqs624_pos->iqs62x;
if (iqs62x->dev_desc->prod_num == IQS625_PROD_NUM)
angle = event_data->interval;
mutex_lock(&iqs624_pos->lock);
if (event_flags & BIT(IQS62X_EVENT_SYS_RESET)) {
ret = iqs624_pos_angle_en(iqs62x, iqs624_pos->angle_en);
if (ret) {
dev_err(indio_dev->dev.parent,
"Failed to re-initialize device: %d\n", ret);
ret = NOTIFY_BAD;
} else {
ret = NOTIFY_OK;
}
} else if (iqs624_pos->angle_en && (angle != iqs624_pos->angle)) {
iio_push_event(indio_dev,
IIO_UNMOD_EVENT_CODE(IIO_ANGL, 0,
IIO_EV_TYPE_CHANGE,
IIO_EV_DIR_NONE),
timestamp);
iqs624_pos->angle = angle;
ret = NOTIFY_OK;
} else {
ret = NOTIFY_DONE;
}
mutex_unlock(&iqs624_pos->lock);
return ret;
}
static void iqs624_pos_notifier_unregister(void *context)
{
struct iqs624_pos_private *iqs624_pos = context;
struct iio_dev *indio_dev = iio_priv_to_dev(iqs624_pos);
int ret;
ret = blocking_notifier_chain_unregister(&iqs624_pos->iqs62x->nh,
&iqs624_pos->notifier);
if (ret)
dev_err(indio_dev->dev.parent,
"Failed to unregister notifier: %d\n", ret);
}
static int iqs624_pos_angle_get(struct iqs62x_core *iqs62x, unsigned int *val)
{
int ret;
__le16 val_buf;
if (iqs62x->dev_desc->prod_num == IQS625_PROD_NUM)
return regmap_read(iqs62x->regmap, iqs62x->dev_desc->interval,
val);
ret = regmap_raw_read(iqs62x->regmap, IQS624_POS_DEG_OUT, &val_buf,
sizeof(val_buf));
if (ret)
return ret;
*val = le16_to_cpu(val_buf);
return 0;
}
static int iqs624_pos_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct iqs624_pos_private *iqs624_pos = iio_priv(indio_dev);
struct iqs62x_core *iqs62x = iqs624_pos->iqs62x;
unsigned int scale = 1;
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = iqs624_pos_angle_get(iqs62x, val);
if (ret)
return ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
if (iqs62x->dev_desc->prod_num == IQS625_PROD_NUM) {
ret = regmap_read(iqs62x->regmap, IQS624_INTERVAL_DIV,
&scale);
if (ret)
return ret;
}
*val = scale * IQS624_POS_SCALE1;
*val2 = IQS624_POS_SCALE2;
return IIO_VAL_FRACTIONAL;
default:
return -EINVAL;
}
}
static int iqs624_pos_read_event_config(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
enum iio_event_direction dir)
{
struct iqs624_pos_private *iqs624_pos = iio_priv(indio_dev);
int ret;
mutex_lock(&iqs624_pos->lock);
ret = iqs624_pos->angle_en;
mutex_unlock(&iqs624_pos->lock);
return ret;
}
static int iqs624_pos_write_event_config(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
enum iio_event_direction dir,
int state)
{
struct iqs624_pos_private *iqs624_pos = iio_priv(indio_dev);
struct iqs62x_core *iqs62x = iqs624_pos->iqs62x;
unsigned int val;
int ret;
mutex_lock(&iqs624_pos->lock);
ret = iqs624_pos_angle_get(iqs62x, &val);
if (ret)
goto err_mutex;
ret = iqs624_pos_angle_en(iqs62x, state);
if (ret)
goto err_mutex;
iqs624_pos->angle = val;
iqs624_pos->angle_en = state;
err_mutex:
mutex_unlock(&iqs624_pos->lock);
return ret;
}
static const struct iio_info iqs624_pos_info = {
.read_raw = &iqs624_pos_read_raw,
.read_event_config = iqs624_pos_read_event_config,
.write_event_config = iqs624_pos_write_event_config,
};
static const struct iio_event_spec iqs624_pos_events[] = {
{
.type = IIO_EV_TYPE_CHANGE,
.dir = IIO_EV_DIR_NONE,
.mask_separate = BIT(IIO_EV_INFO_ENABLE),
},
};
static const struct iio_chan_spec iqs624_pos_channels[] = {
{
.type = IIO_ANGL,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
.event_spec = iqs624_pos_events,
.num_event_specs = ARRAY_SIZE(iqs624_pos_events),
},
};
static int iqs624_pos_probe(struct platform_device *pdev)
{
struct iqs62x_core *iqs62x = dev_get_drvdata(pdev->dev.parent);
struct iqs624_pos_private *iqs624_pos;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*iqs624_pos));
if (!indio_dev)
return -ENOMEM;
iqs624_pos = iio_priv(indio_dev);
iqs624_pos->iqs62x = iqs62x;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->dev.parent = &pdev->dev;
indio_dev->channels = iqs624_pos_channels;
indio_dev->num_channels = ARRAY_SIZE(iqs624_pos_channels);
indio_dev->name = iqs62x->dev_desc->dev_name;
indio_dev->info = &iqs624_pos_info;
mutex_init(&iqs624_pos->lock);
iqs624_pos->notifier.notifier_call = iqs624_pos_notifier;
ret = blocking_notifier_chain_register(&iqs624_pos->iqs62x->nh,
&iqs624_pos->notifier);
if (ret) {
dev_err(&pdev->dev, "Failed to register notifier: %d\n", ret);
return ret;
}
ret = devm_add_action_or_reset(&pdev->dev,
iqs624_pos_notifier_unregister,
iqs624_pos);
if (ret)
return ret;
return devm_iio_device_register(&pdev->dev, indio_dev);
}
static struct platform_driver iqs624_pos_platform_driver = {
.driver = {
.name = "iqs624-pos",
},
.probe = iqs624_pos_probe,
};
module_platform_driver(iqs624_pos_platform_driver);
MODULE_AUTHOR("Jeff LaBundy <jeff@labundy.com>");
MODULE_DESCRIPTION("Azoteq IQS624/625 Angular Position Sensors");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:iqs624-pos");
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