iio: position: Add support for Azoteq IQS624/625 angle sensors (189c3c49) · Commits · EulixOS / Software / Kernel

drivers/iio/Kconfig

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		@@ -88,6 +88,7 @@ source "drivers/iio/orientation/Kconfig"
		if IIO_TRIGGER
		source "drivers/iio/trigger/Kconfig"
		endif #IIO_TRIGGER
		source "drivers/iio/position/Kconfig"
		source "drivers/iio/potentiometer/Kconfig"
		source "drivers/iio/potentiostat/Kconfig"
		source "drivers/iio/pressure/Kconfig"

drivers/iio/Makefile

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		@@ -31,6 +31,7 @@ obj-y += light/
		obj-y += magnetometer/
		obj-y += multiplexer/
		obj-y += orientation/
		obj-y += position/
		obj-y += potentiometer/
		obj-y += potentiostat/
		obj-y += pressure/

drivers/iio/position/Kconfig

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		# 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

drivers/iio/position/Makefile

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		#
		# 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

drivers/iio/position/iqs624-pos.c

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		// 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");