drivers/iio/accel/adxl345_core.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * ADXL345 3-Axis Digital Accelerometer IIO core driver
  *
  * Copyright (c) 2017 Eva Rachel Retuya <eraretuya@gmail.com>
  *
  * Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ADXL345.pdf
  */

 #include <linux/module.h>
 #include <linux/property.h>
 #include <linux/regmap.h>
 #include <linux/units.h>

 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>

 #include "adxl345.h"

 struct adxl345_data {
 	const struct adxl345_chip_info *info;
 	struct regmap *regmap;
 };

 #define ADXL345_CHANNEL(index, axis) {					\
 	.type = IIO_ACCEL,						\
 	.modified = 1,							\
 	.channel2 = IIO_MOD_##axis,					\
 	.address = index,						\
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
 		BIT(IIO_CHAN_INFO_CALIBBIAS),				\
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\
 		BIT(IIO_CHAN_INFO_SAMP_FREQ),				\
 }

 static const struct iio_chan_spec adxl345_channels[] = {
 	ADXL345_CHANNEL(0, X),
 	ADXL345_CHANNEL(1, Y),
 	ADXL345_CHANNEL(2, Z),
 };

 static int adxl345_read_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan,
 			    int *val, int *val2, long mask)
 {
 	struct adxl345_data *data = iio_priv(indio_dev);
 	__le16 accel;
 	long long samp_freq_nhz;
 	unsigned int regval;
 	int ret;

 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		/*
 		 * Data is stored in adjacent registers:
 		 * ADXL345_REG_DATA(X0/Y0/Z0) contain the least significant byte
 		 * and ADXL345_REG_DATA(X0/Y0/Z0) + 1 the most significant byte
 		 */
 		ret = regmap_bulk_read(data->regmap,
 				       ADXL345_REG_DATA_AXIS(chan->address),
 				       &accel, sizeof(accel));
 		if (ret < 0)
 			return ret;

 		*val = sign_extend32(le16_to_cpu(accel), 12);
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
 		*val = 0;
 		*val2 = data->info->uscale;
 		return IIO_VAL_INT_PLUS_MICRO;
 	case IIO_CHAN_INFO_CALIBBIAS:
 		ret = regmap_read(data->regmap,
 				  ADXL345_REG_OFS_AXIS(chan->address), &regval);
 		if (ret < 0)
 			return ret;
 		/*
 		 * 8-bit resolution at +/- 2g, that is 4x accel data scale
 		 * factor
 		 */
 		*val = sign_extend32(regval, 7) * 4;

 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		ret = regmap_read(data->regmap, ADXL345_REG_BW_RATE, &regval);
 		if (ret < 0)
 			return ret;

 		samp_freq_nhz = ADXL345_BASE_RATE_NANO_HZ <<
 				(regval & ADXL345_BW_RATE);
 		*val = div_s64_rem(samp_freq_nhz, NANOHZ_PER_HZ, val2);

 		return IIO_VAL_INT_PLUS_NANO;
 	}

 	return -EINVAL;
 }

 static int adxl345_write_raw(struct iio_dev *indio_dev,
 			     struct iio_chan_spec const *chan,
 			     int val, int val2, long mask)
 {
 	struct adxl345_data *data = iio_priv(indio_dev);
 	s64 n;

 	switch (mask) {
 	case IIO_CHAN_INFO_CALIBBIAS:
 		/*
 		 * 8-bit resolution at +/- 2g, that is 4x accel data scale
 		 * factor
 		 */
 		return regmap_write(data->regmap,
 				    ADXL345_REG_OFS_AXIS(chan->address),
 				    val / 4);
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		n = div_s64(val * NANOHZ_PER_HZ + val2,
 			    ADXL345_BASE_RATE_NANO_HZ);

 		return regmap_update_bits(data->regmap, ADXL345_REG_BW_RATE,
 					  ADXL345_BW_RATE,
 					  clamp_val(ilog2(n), 0,
 						    ADXL345_BW_RATE));
 	}

 	return -EINVAL;
 }

 static int adxl345_write_raw_get_fmt(struct iio_dev *indio_dev,
 				     struct iio_chan_spec const *chan,
 				     long mask)
 {
 	switch (mask) {
 	case IIO_CHAN_INFO_CALIBBIAS:
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		return IIO_VAL_INT_PLUS_NANO;
 	default:
 		return -EINVAL;
 	}
 }

 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
 "0.09765625 0.1953125 0.390625 0.78125 1.5625 3.125 6.25 12.5 25 50 100 200 400 800 1600 3200"
 );

 static struct attribute *adxl345_attrs[] = {
 	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
 	NULL
 };

 static const struct attribute_group adxl345_attrs_group = {
 	.attrs = adxl345_attrs,
 };

 static const struct iio_info adxl345_info = {
 	.attrs		= &adxl345_attrs_group,
 	.read_raw	= adxl345_read_raw,
 	.write_raw	= adxl345_write_raw,
 	.write_raw_get_fmt	= adxl345_write_raw_get_fmt,
 };

 static int adxl345_powerup(void *regmap)
 {
 	return regmap_write(regmap, ADXL345_REG_POWER_CTL, ADXL345_POWER_CTL_MEASURE);
 }

 static void adxl345_powerdown(void *regmap)
 {
 	regmap_write(regmap, ADXL345_REG_POWER_CTL, ADXL345_POWER_CTL_STANDBY);
 }

 /**
  * adxl345_core_probe() - probe and setup for the adxl345 accelerometer,
  *                        also covers the adlx375 accelerometer
  * @dev:	Driver model representation of the device
  * @regmap:	Regmap instance for the device
  * @setup:	Setup routine to be executed right before the standard device
  *		setup
  *
  * Return: 0 on success, negative errno on error
  */
 int adxl345_core_probe(struct device *dev, struct regmap *regmap,
 		       int (*setup)(struct device*, struct regmap*))
 {
 	struct adxl345_data *data;
 	struct iio_dev *indio_dev;
 	u32 regval;
 	unsigned int data_format_mask = (ADXL345_DATA_FORMAT_RANGE |
 					 ADXL345_DATA_FORMAT_JUSTIFY |
 					 ADXL345_DATA_FORMAT_FULL_RES |
 					 ADXL345_DATA_FORMAT_SELF_TEST);
 	int ret;

 	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
 	if (!indio_dev)
 		return -ENOMEM;

 	data = iio_priv(indio_dev);
 	data->regmap = regmap;
 	data->info = device_get_match_data(dev);
 	if (!data->info)
 		return -ENODEV;

 	indio_dev->name = data->info->name;
 	indio_dev->info = &adxl345_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = adxl345_channels;
 	indio_dev->num_channels = ARRAY_SIZE(adxl345_channels);

 	if (setup) {
 		/* Perform optional initial bus specific configuration */
 		ret = setup(dev, data->regmap);
 		if (ret)
 			return ret;

 		/* Enable full-resolution mode */
 		ret = regmap_update_bits(data->regmap, ADXL345_REG_DATA_FORMAT,
 					 data_format_mask,
 					 ADXL345_DATA_FORMAT_FULL_RES);
 		if (ret)
 			return dev_err_probe(dev, ret,
 					     "Failed to set data range\n");

 	} else {
 		/* Enable full-resolution mode (init all data_format bits) */
 		ret = regmap_write(data->regmap, ADXL345_REG_DATA_FORMAT,
 				   ADXL345_DATA_FORMAT_FULL_RES);
 		if (ret)
 			return dev_err_probe(dev, ret,
 					     "Failed to set data range\n");
 	}

 	ret = regmap_read(data->regmap, ADXL345_REG_DEVID, &regval);
 	if (ret < 0)
 		return dev_err_probe(dev, ret, "Error reading device ID\n");

 	if (regval != ADXL345_DEVID)
 		return dev_err_probe(dev, -ENODEV, "Invalid device ID: %x, expected %x\n",
 				     regval, ADXL345_DEVID);

 	/* Enable measurement mode */
 	ret = adxl345_powerup(data->regmap);
 	if (ret < 0)
 		return dev_err_probe(dev, ret, "Failed to enable measurement mode\n");

 	ret = devm_add_action_or_reset(dev, adxl345_powerdown, data->regmap);
 	if (ret < 0)
 		return ret;

 	return devm_iio_device_register(dev, indio_dev);
 }
 EXPORT_SYMBOL_NS_GPL(adxl345_core_probe, IIO_ADXL345);

 MODULE_AUTHOR("Eva Rachel Retuya <eraretuya@gmail.com>");
 MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer core driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* ADXL345 3-Axis Digital Accelerometer IIO core driver
	*
	* Copyright (c) 2017 Eva Rachel Retuya <eraretuya@gmail.com>
	*
	* Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ADXL345.pdf
	*/

	#include <linux/module.h>
	#include <linux/property.h>
	#include <linux/regmap.h>
	#include <linux/units.h>

	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>

	#include "adxl345.h"

	struct adxl345_data {
	const struct adxl345_chip_info *info;
	struct regmap *regmap;
	};

	#define ADXL345_CHANNEL(index, axis) { \
	.type = IIO_ACCEL, \
	.modified = 1, \
	.channel2 = IIO_MOD_##axis, \
	.address = index, \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \| \
	BIT(IIO_CHAN_INFO_CALIBBIAS), \
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \| \
	BIT(IIO_CHAN_INFO_SAMP_FREQ), \
	}

	static const struct iio_chan_spec adxl345_channels[] = {
	ADXL345_CHANNEL(0, X),
	ADXL345_CHANNEL(1, Y),
	ADXL345_CHANNEL(2, Z),
	};

	static int adxl345_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct adxl345_data *data = iio_priv(indio_dev);
	__le16 accel;
	long long samp_freq_nhz;
	unsigned int regval;
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
	/*
	* Data is stored in adjacent registers:
	* ADXL345_REG_DATA(X0/Y0/Z0) contain the least significant byte
	* and ADXL345_REG_DATA(X0/Y0/Z0) + 1 the most significant byte
	*/
	ret = regmap_bulk_read(data->regmap,
	ADXL345_REG_DATA_AXIS(chan->address),
	&accel, sizeof(accel));
	if (ret < 0)
	return ret;

	*val = sign_extend32(le16_to_cpu(accel), 12);
	return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
	*val = 0;
	*val2 = data->info->uscale;
	return IIO_VAL_INT_PLUS_MICRO;
	case IIO_CHAN_INFO_CALIBBIAS:
	ret = regmap_read(data->regmap,
	ADXL345_REG_OFS_AXIS(chan->address), &regval);
	if (ret < 0)
	return ret;
	/*
	* 8-bit resolution at +/- 2g, that is 4x accel data scale
	* factor
	*/
	val = sign_extend32(regval, 7) 4;

	return IIO_VAL_INT;
	case IIO_CHAN_INFO_SAMP_FREQ:
	ret = regmap_read(data->regmap, ADXL345_REG_BW_RATE, &regval);
	if (ret < 0)
	return ret;

	samp_freq_nhz = ADXL345_BASE_RATE_NANO_HZ <<
	(regval & ADXL345_BW_RATE);
	*val = div_s64_rem(samp_freq_nhz, NANOHZ_PER_HZ, val2);

	return IIO_VAL_INT_PLUS_NANO;
	}

	return -EINVAL;
	}

	static int adxl345_write_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct adxl345_data *data = iio_priv(indio_dev);
	s64 n;

	switch (mask) {
	case IIO_CHAN_INFO_CALIBBIAS:
	/*
	* 8-bit resolution at +/- 2g, that is 4x accel data scale
	* factor
	*/
	return regmap_write(data->regmap,
	ADXL345_REG_OFS_AXIS(chan->address),
	val / 4);
	case IIO_CHAN_INFO_SAMP_FREQ:
	n = div_s64(val * NANOHZ_PER_HZ + val2,
	ADXL345_BASE_RATE_NANO_HZ);

	return regmap_update_bits(data->regmap, ADXL345_REG_BW_RATE,
	ADXL345_BW_RATE,
	clamp_val(ilog2(n), 0,
	ADXL345_BW_RATE));
	}

	return -EINVAL;
	}

	static int adxl345_write_raw_get_fmt(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	long mask)
	{
	switch (mask) {
	case IIO_CHAN_INFO_CALIBBIAS:
	return IIO_VAL_INT;
	case IIO_CHAN_INFO_SAMP_FREQ:
	return IIO_VAL_INT_PLUS_NANO;
	default:
	return -EINVAL;
	}
	}

	static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
	"0.09765625 0.1953125 0.390625 0.78125 1.5625 3.125 6.25 12.5 25 50 100 200 400 800 1600 3200"
	);

	static struct attribute *adxl345_attrs[] = {
	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
	NULL
	};

	static const struct attribute_group adxl345_attrs_group = {
	.attrs = adxl345_attrs,
	};

	static const struct iio_info adxl345_info = {
	.attrs = &adxl345_attrs_group,
	.read_raw = adxl345_read_raw,
	.write_raw = adxl345_write_raw,
	.write_raw_get_fmt = adxl345_write_raw_get_fmt,
	};

	static int adxl345_powerup(void *regmap)
	{
	return regmap_write(regmap, ADXL345_REG_POWER_CTL, ADXL345_POWER_CTL_MEASURE);
	}

	static void adxl345_powerdown(void *regmap)
	{
	regmap_write(regmap, ADXL345_REG_POWER_CTL, ADXL345_POWER_CTL_STANDBY);
	}

	/**
	* adxl345_core_probe() - probe and setup for the adxl345 accelerometer,
	* also covers the adlx375 accelerometer
	* @dev: Driver model representation of the device
	* @regmap: Regmap instance for the device
	* @setup: Setup routine to be executed right before the standard device
	* setup
	*
	* Return: 0 on success, negative errno on error
	*/
	int adxl345_core_probe(struct device dev, struct regmap regmap,
	int (setup)(struct device, struct regmap*))
	{
	struct adxl345_data *data;
	struct iio_dev *indio_dev;
	u32 regval;
	unsigned int data_format_mask = (ADXL345_DATA_FORMAT_RANGE \|
	ADXL345_DATA_FORMAT_JUSTIFY \|
	ADXL345_DATA_FORMAT_FULL_RES \|
	ADXL345_DATA_FORMAT_SELF_TEST);
	int ret;

	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
	if (!indio_dev)
	return -ENOMEM;

	data = iio_priv(indio_dev);
	data->regmap = regmap;
	data->info = device_get_match_data(dev);
	if (!data->info)
	return -ENODEV;

	indio_dev->name = data->info->name;
	indio_dev->info = &adxl345_info;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = adxl345_channels;
	indio_dev->num_channels = ARRAY_SIZE(adxl345_channels);

	if (setup) {
	/* Perform optional initial bus specific configuration */
	ret = setup(dev, data->regmap);
	if (ret)
	return ret;

	/* Enable full-resolution mode */
	ret = regmap_update_bits(data->regmap, ADXL345_REG_DATA_FORMAT,
	data_format_mask,
	ADXL345_DATA_FORMAT_FULL_RES);
	if (ret)
	return dev_err_probe(dev, ret,
	"Failed to set data range\n");

	} else {
	/* Enable full-resolution mode (init all data_format bits) */
	ret = regmap_write(data->regmap, ADXL345_REG_DATA_FORMAT,
	ADXL345_DATA_FORMAT_FULL_RES);
	if (ret)
	return dev_err_probe(dev, ret,
	"Failed to set data range\n");
	}

	ret = regmap_read(data->regmap, ADXL345_REG_DEVID, &regval);
	if (ret < 0)
	return dev_err_probe(dev, ret, "Error reading device ID\n");

	if (regval != ADXL345_DEVID)
	return dev_err_probe(dev, -ENODEV, "Invalid device ID: %x, expected %x\n",
	regval, ADXL345_DEVID);

	/* Enable measurement mode */
	ret = adxl345_powerup(data->regmap);
	if (ret < 0)
	return dev_err_probe(dev, ret, "Failed to enable measurement mode\n");

	ret = devm_add_action_or_reset(dev, adxl345_powerdown, data->regmap);
	if (ret < 0)
	return ret;

	return devm_iio_device_register(dev, indio_dev);
	}
	EXPORT_SYMBOL_NS_GPL(adxl345_core_probe, IIO_ADXL345);

	MODULE_AUTHOR("Eva Rachel Retuya <eraretuya@gmail.com>");
	MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer core driver");
	MODULE_LICENSE("GPL v2");