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: Jeff LaBundy <jeff@labundy.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
This commit is contained in:
Jeff LaBundy
Lee Jones
Родитель
b081b73820
Коммит
189c3c495a
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@ -88,6 +88,7 @@ source "drivers/iio/orientation/Kconfig"
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if IIO_TRIGGER
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source "drivers/iio/trigger/Kconfig"
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endif #IIO_TRIGGER
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source "drivers/iio/position/Kconfig"
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source "drivers/iio/potentiometer/Kconfig"
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source "drivers/iio/potentiostat/Kconfig"
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source "drivers/iio/pressure/Kconfig"
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@ -31,6 +31,7 @@ obj-y += light/
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obj-y += magnetometer/
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obj-y += multiplexer/
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obj-y += orientation/
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obj-y += position/
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obj-y += potentiometer/
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obj-y += potentiostat/
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obj-y += pressure/
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@ -0,0 +1,19 @@
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# SPDX-License-Identifier: GPL-2.0-only
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#
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# Linear and angular position sensors
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#
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# When adding new entries keep the list in alphabetical order
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menu "Linear and angular position sensors"
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config IQS624_POS
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tristate "Azoteq IQS624/625 angular position sensors"
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depends on MFD_IQS62X || COMPILE_TEST
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help
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Say Y here if you want to build support for the Azoteq IQS624
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and IQS625 angular position sensors.
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To compile this driver as a module, choose M here: the module
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will be called iqs624-pos.
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endmenu
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@ -0,0 +1,7 @@
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#
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# Makefile for IIO linear and angular position sensors
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#
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# When adding new entries keep the list in alphabetical order
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obj-$(CONFIG_IQS624_POS) += iqs624-pos.o
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@ -0,0 +1,284 @@
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// SPDX-License-Identifier: GPL-2.0+
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/*
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* Azoteq IQS624/625 Angular Position Sensors
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*
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* Copyright (C) 2019 Jeff LaBundy <jeff@labundy.com>
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*/
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#include <linux/device.h>
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#include <linux/iio/events.h>
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#include <linux/iio/iio.h>
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#include <linux/kernel.h>
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#include <linux/mfd/iqs62x.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/notifier.h>
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#include <linux/platform_device.h>
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#include <linux/regmap.h>
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#define IQS624_POS_DEG_OUT 0x16
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#define IQS624_POS_SCALE1 (314159 / 180)
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#define IQS624_POS_SCALE2 100000
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struct iqs624_pos_private {
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struct iqs62x_core *iqs62x;
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struct notifier_block notifier;
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struct mutex lock;
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bool angle_en;
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u16 angle;
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};
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static int iqs624_pos_angle_en(struct iqs62x_core *iqs62x, bool angle_en)
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{
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unsigned int event_mask = IQS624_HALL_UI_WHL_EVENT;
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/*
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* The IQS625 reports angular position in the form of coarse intervals,
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* so only interval change events are unmasked. Conversely, the IQS624
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* reports angular position down to one degree of resolution, so wheel
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* movement events are unmasked instead.
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*/
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if (iqs62x->dev_desc->prod_num == IQS625_PROD_NUM)
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event_mask = IQS624_HALL_UI_INT_EVENT;
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return regmap_update_bits(iqs62x->regmap, IQS624_HALL_UI, event_mask,
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angle_en ? 0 : 0xFF);
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}
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static int iqs624_pos_notifier(struct notifier_block *notifier,
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unsigned long event_flags, void *context)
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{
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struct iqs62x_event_data *event_data = context;
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struct iqs624_pos_private *iqs624_pos;
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struct iqs62x_core *iqs62x;
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struct iio_dev *indio_dev;
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u16 angle = event_data->ui_data;
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s64 timestamp;
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int ret;
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iqs624_pos = container_of(notifier, struct iqs624_pos_private,
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notifier);
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indio_dev = iio_priv_to_dev(iqs624_pos);
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timestamp = iio_get_time_ns(indio_dev);
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iqs62x = iqs624_pos->iqs62x;
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if (iqs62x->dev_desc->prod_num == IQS625_PROD_NUM)
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angle = event_data->interval;
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mutex_lock(&iqs624_pos->lock);
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if (event_flags & BIT(IQS62X_EVENT_SYS_RESET)) {
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ret = iqs624_pos_angle_en(iqs62x, iqs624_pos->angle_en);
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if (ret) {
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dev_err(indio_dev->dev.parent,
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"Failed to re-initialize device: %d\n", ret);
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ret = NOTIFY_BAD;
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} else {
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ret = NOTIFY_OK;
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}
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} else if (iqs624_pos->angle_en && (angle != iqs624_pos->angle)) {
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iio_push_event(indio_dev,
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IIO_UNMOD_EVENT_CODE(IIO_ANGL, 0,
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IIO_EV_TYPE_CHANGE,
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IIO_EV_DIR_NONE),
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timestamp);
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iqs624_pos->angle = angle;
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ret = NOTIFY_OK;
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} else {
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ret = NOTIFY_DONE;
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}
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mutex_unlock(&iqs624_pos->lock);
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return ret;
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}
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static void iqs624_pos_notifier_unregister(void *context)
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{
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struct iqs624_pos_private *iqs624_pos = context;
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struct iio_dev *indio_dev = iio_priv_to_dev(iqs624_pos);
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int ret;
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ret = blocking_notifier_chain_unregister(&iqs624_pos->iqs62x->nh,
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&iqs624_pos->notifier);
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if (ret)
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dev_err(indio_dev->dev.parent,
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"Failed to unregister notifier: %d\n", ret);
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}
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static int iqs624_pos_angle_get(struct iqs62x_core *iqs62x, unsigned int *val)
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{
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int ret;
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__le16 val_buf;
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if (iqs62x->dev_desc->prod_num == IQS625_PROD_NUM)
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return regmap_read(iqs62x->regmap, iqs62x->dev_desc->interval,
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val);
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ret = regmap_raw_read(iqs62x->regmap, IQS624_POS_DEG_OUT, &val_buf,
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sizeof(val_buf));
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if (ret)
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return ret;
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*val = le16_to_cpu(val_buf);
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return 0;
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}
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static int iqs624_pos_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long mask)
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{
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struct iqs624_pos_private *iqs624_pos = iio_priv(indio_dev);
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struct iqs62x_core *iqs62x = iqs624_pos->iqs62x;
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unsigned int scale = 1;
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int ret;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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ret = iqs624_pos_angle_get(iqs62x, val);
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if (ret)
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return ret;
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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if (iqs62x->dev_desc->prod_num == IQS625_PROD_NUM) {
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ret = regmap_read(iqs62x->regmap, IQS624_INTERVAL_DIV,
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&scale);
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if (ret)
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return ret;
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}
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*val = scale * IQS624_POS_SCALE1;
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*val2 = IQS624_POS_SCALE2;
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return IIO_VAL_FRACTIONAL;
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default:
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return -EINVAL;
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}
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}
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static int iqs624_pos_read_event_config(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan,
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enum iio_event_type type,
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enum iio_event_direction dir)
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{
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struct iqs624_pos_private *iqs624_pos = iio_priv(indio_dev);
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int ret;
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mutex_lock(&iqs624_pos->lock);
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ret = iqs624_pos->angle_en;
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mutex_unlock(&iqs624_pos->lock);
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return ret;
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}
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static int iqs624_pos_write_event_config(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan,
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enum iio_event_type type,
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enum iio_event_direction dir,
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int state)
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{
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struct iqs624_pos_private *iqs624_pos = iio_priv(indio_dev);
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struct iqs62x_core *iqs62x = iqs624_pos->iqs62x;
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unsigned int val;
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int ret;
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mutex_lock(&iqs624_pos->lock);
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ret = iqs624_pos_angle_get(iqs62x, &val);
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if (ret)
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goto err_mutex;
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ret = iqs624_pos_angle_en(iqs62x, state);
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if (ret)
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goto err_mutex;
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iqs624_pos->angle = val;
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iqs624_pos->angle_en = state;
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err_mutex:
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mutex_unlock(&iqs624_pos->lock);
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return ret;
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}
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static const struct iio_info iqs624_pos_info = {
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.read_raw = &iqs624_pos_read_raw,
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.read_event_config = iqs624_pos_read_event_config,
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.write_event_config = iqs624_pos_write_event_config,
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};
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static const struct iio_event_spec iqs624_pos_events[] = {
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{
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.type = IIO_EV_TYPE_CHANGE,
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.dir = IIO_EV_DIR_NONE,
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.mask_separate = BIT(IIO_EV_INFO_ENABLE),
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},
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};
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static const struct iio_chan_spec iqs624_pos_channels[] = {
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{
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.type = IIO_ANGL,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
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BIT(IIO_CHAN_INFO_SCALE),
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.event_spec = iqs624_pos_events,
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.num_event_specs = ARRAY_SIZE(iqs624_pos_events),
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},
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};
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static int iqs624_pos_probe(struct platform_device *pdev)
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{
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struct iqs62x_core *iqs62x = dev_get_drvdata(pdev->dev.parent);
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struct iqs624_pos_private *iqs624_pos;
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struct iio_dev *indio_dev;
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int ret;
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indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*iqs624_pos));
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if (!indio_dev)
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return -ENOMEM;
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iqs624_pos = iio_priv(indio_dev);
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iqs624_pos->iqs62x = iqs62x;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->dev.parent = &pdev->dev;
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indio_dev->channels = iqs624_pos_channels;
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indio_dev->num_channels = ARRAY_SIZE(iqs624_pos_channels);
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indio_dev->name = iqs62x->dev_desc->dev_name;
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indio_dev->info = &iqs624_pos_info;
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mutex_init(&iqs624_pos->lock);
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iqs624_pos->notifier.notifier_call = iqs624_pos_notifier;
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ret = blocking_notifier_chain_register(&iqs624_pos->iqs62x->nh,
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&iqs624_pos->notifier);
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if (ret) {
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dev_err(&pdev->dev, "Failed to register notifier: %d\n", ret);
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return ret;
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}
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ret = devm_add_action_or_reset(&pdev->dev,
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iqs624_pos_notifier_unregister,
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iqs624_pos);
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if (ret)
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return ret;
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return devm_iio_device_register(&pdev->dev, indio_dev);
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}
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static struct platform_driver iqs624_pos_platform_driver = {
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.driver = {
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.name = "iqs624-pos",
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},
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.probe = iqs624_pos_probe,
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};
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module_platform_driver(iqs624_pos_platform_driver);
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MODULE_AUTHOR("Jeff LaBundy <jeff@labundy.com>");
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MODULE_DESCRIPTION("Azoteq IQS624/625 Angular Position Sensors");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:iqs624-pos");
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