diff options
author | Jeff LaBundy <jeff@labundy.com> | 2020-02-17 02:32:11 +0300 |
---|---|---|
committer | Lee Jones <lee.jones@linaro.org> | 2020-03-27 11:25:59 +0300 |
commit | 189c3c495ad7382099a641664171d8b047d9e9b5 (patch) | |
tree | 67552a6a6408f6be0b5e5d700c5ea0c2cb7572d8 | |
parent | b081b73820945decb2fd39bdc0ccf46a1ddc6d53 (diff) | |
download | linux-189c3c495ad7382099a641664171d8b047d9e9b5.tar.xz |
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>
-rw-r--r-- | drivers/iio/Kconfig | 1 | ||||
-rw-r--r-- | drivers/iio/Makefile | 1 | ||||
-rw-r--r-- | drivers/iio/position/Kconfig | 19 | ||||
-rw-r--r-- | drivers/iio/position/Makefile | 7 | ||||
-rw-r--r-- | drivers/iio/position/iqs624-pos.c | 284 |
5 files changed, 312 insertions, 0 deletions
diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig index 5bd51853b15e..d5c073a8aa3e 100644 --- a/drivers/iio/Kconfig +++ b/drivers/iio/Kconfig @@ -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" diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile index bff682ad1cfb..1712011c0f4a 100644 --- a/drivers/iio/Makefile +++ b/drivers/iio/Makefile @@ -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/ diff --git a/drivers/iio/position/Kconfig b/drivers/iio/position/Kconfig new file mode 100644 index 000000000000..eda67f008c5b --- /dev/null +++ b/drivers/iio/position/Kconfig @@ -0,0 +1,19 @@ +# 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 diff --git a/drivers/iio/position/Makefile b/drivers/iio/position/Makefile new file mode 100644 index 000000000000..3cbe7a734352 --- /dev/null +++ b/drivers/iio/position/Makefile @@ -0,0 +1,7 @@ +# +# 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 diff --git a/drivers/iio/position/iqs624-pos.c b/drivers/iio/position/iqs624-pos.c new file mode 100644 index 000000000000..77096c31c2ba --- /dev/null +++ b/drivers/iio/position/iqs624-pos.c @@ -0,0 +1,284 @@ +// 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"); |