34ca62caa0
Add a comment to the probe() function to describe the passed function pointer argument in particular. Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com> Link: https://lore.kernel.org/r/20240401194906.56810-8-l.rubusch@gmail.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
256 lines
6.7 KiB
C
256 lines
6.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* ADXL345 3-Axis Digital Accelerometer IIO core driver
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*
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* Copyright (c) 2017 Eva Rachel Retuya <eraretuya@gmail.com>
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*
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* Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ADXL345.pdf
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*/
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#include <linux/module.h>
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#include <linux/property.h>
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#include <linux/regmap.h>
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#include <linux/units.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#include "adxl345.h"
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struct adxl345_data {
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const struct adxl345_chip_info *info;
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struct regmap *regmap;
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};
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#define ADXL345_CHANNEL(index, axis) { \
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.type = IIO_ACCEL, \
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.modified = 1, \
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.channel2 = IIO_MOD_##axis, \
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.address = index, \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
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BIT(IIO_CHAN_INFO_CALIBBIAS), \
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
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BIT(IIO_CHAN_INFO_SAMP_FREQ), \
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}
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static const struct iio_chan_spec adxl345_channels[] = {
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ADXL345_CHANNEL(0, X),
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ADXL345_CHANNEL(1, Y),
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ADXL345_CHANNEL(2, Z),
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};
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static int adxl345_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 adxl345_data *data = iio_priv(indio_dev);
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__le16 accel;
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long long samp_freq_nhz;
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unsigned int regval;
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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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/*
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* Data is stored in adjacent registers:
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* ADXL345_REG_DATA(X0/Y0/Z0) contain the least significant byte
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* and ADXL345_REG_DATA(X0/Y0/Z0) + 1 the most significant byte
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*/
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ret = regmap_bulk_read(data->regmap,
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ADXL345_REG_DATA_AXIS(chan->address),
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&accel, sizeof(accel));
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if (ret < 0)
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return ret;
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*val = sign_extend32(le16_to_cpu(accel), 12);
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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*val = 0;
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*val2 = data->info->uscale;
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return IIO_VAL_INT_PLUS_MICRO;
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case IIO_CHAN_INFO_CALIBBIAS:
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ret = regmap_read(data->regmap,
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ADXL345_REG_OFS_AXIS(chan->address), ®val);
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if (ret < 0)
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return ret;
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/*
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* 8-bit resolution at +/- 2g, that is 4x accel data scale
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* factor
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*/
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*val = sign_extend32(regval, 7) * 4;
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SAMP_FREQ:
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ret = regmap_read(data->regmap, ADXL345_REG_BW_RATE, ®val);
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if (ret < 0)
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return ret;
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samp_freq_nhz = ADXL345_BASE_RATE_NANO_HZ <<
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(regval & ADXL345_BW_RATE);
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*val = div_s64_rem(samp_freq_nhz, NANOHZ_PER_HZ, val2);
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return IIO_VAL_INT_PLUS_NANO;
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}
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return -EINVAL;
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}
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static int adxl345_write_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 adxl345_data *data = iio_priv(indio_dev);
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s64 n;
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switch (mask) {
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case IIO_CHAN_INFO_CALIBBIAS:
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/*
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* 8-bit resolution at +/- 2g, that is 4x accel data scale
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* factor
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*/
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return regmap_write(data->regmap,
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ADXL345_REG_OFS_AXIS(chan->address),
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val / 4);
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case IIO_CHAN_INFO_SAMP_FREQ:
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n = div_s64(val * NANOHZ_PER_HZ + val2,
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ADXL345_BASE_RATE_NANO_HZ);
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return regmap_update_bits(data->regmap, ADXL345_REG_BW_RATE,
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ADXL345_BW_RATE,
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clamp_val(ilog2(n), 0,
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ADXL345_BW_RATE));
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}
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return -EINVAL;
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}
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static int adxl345_write_raw_get_fmt(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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long mask)
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{
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switch (mask) {
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case IIO_CHAN_INFO_CALIBBIAS:
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SAMP_FREQ:
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return IIO_VAL_INT_PLUS_NANO;
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default:
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return -EINVAL;
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}
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}
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static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
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"0.09765625 0.1953125 0.390625 0.78125 1.5625 3.125 6.25 12.5 25 50 100 200 400 800 1600 3200"
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);
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static struct attribute *adxl345_attrs[] = {
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&iio_const_attr_sampling_frequency_available.dev_attr.attr,
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NULL
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};
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static const struct attribute_group adxl345_attrs_group = {
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.attrs = adxl345_attrs,
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};
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static const struct iio_info adxl345_info = {
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.attrs = &adxl345_attrs_group,
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.read_raw = adxl345_read_raw,
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.write_raw = adxl345_write_raw,
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.write_raw_get_fmt = adxl345_write_raw_get_fmt,
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};
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static int adxl345_powerup(void *regmap)
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{
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return regmap_write(regmap, ADXL345_REG_POWER_CTL, ADXL345_POWER_CTL_MEASURE);
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}
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static void adxl345_powerdown(void *regmap)
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{
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regmap_write(regmap, ADXL345_REG_POWER_CTL, ADXL345_POWER_CTL_STANDBY);
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}
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/**
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* adxl345_core_probe() - probe and setup for the adxl345 accelerometer,
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* also covers the adlx375 accelerometer
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* @dev: Driver model representation of the device
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* @regmap: Regmap instance for the device
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* @setup: Setup routine to be executed right before the standard device
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* setup
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*
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* Return: 0 on success, negative errno on error
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*/
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int adxl345_core_probe(struct device *dev, struct regmap *regmap,
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int (*setup)(struct device*, struct regmap*))
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{
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struct adxl345_data *data;
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struct iio_dev *indio_dev;
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u32 regval;
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unsigned int data_format_mask = (ADXL345_DATA_FORMAT_RANGE |
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ADXL345_DATA_FORMAT_JUSTIFY |
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ADXL345_DATA_FORMAT_FULL_RES |
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ADXL345_DATA_FORMAT_SELF_TEST);
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int ret;
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indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
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if (!indio_dev)
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return -ENOMEM;
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data = iio_priv(indio_dev);
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data->regmap = regmap;
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data->info = device_get_match_data(dev);
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if (!data->info)
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return -ENODEV;
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indio_dev->name = data->info->name;
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indio_dev->info = &adxl345_info;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = adxl345_channels;
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indio_dev->num_channels = ARRAY_SIZE(adxl345_channels);
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if (setup) {
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/* Perform optional initial bus specific configuration */
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ret = setup(dev, data->regmap);
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if (ret)
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return ret;
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/* Enable full-resolution mode */
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ret = regmap_update_bits(data->regmap, ADXL345_REG_DATA_FORMAT,
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data_format_mask,
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ADXL345_DATA_FORMAT_FULL_RES);
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if (ret)
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return dev_err_probe(dev, ret,
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"Failed to set data range\n");
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} else {
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/* Enable full-resolution mode (init all data_format bits) */
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ret = regmap_write(data->regmap, ADXL345_REG_DATA_FORMAT,
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ADXL345_DATA_FORMAT_FULL_RES);
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if (ret)
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return dev_err_probe(dev, ret,
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"Failed to set data range\n");
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}
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ret = regmap_read(data->regmap, ADXL345_REG_DEVID, ®val);
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if (ret < 0)
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return dev_err_probe(dev, ret, "Error reading device ID\n");
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if (regval != ADXL345_DEVID)
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return dev_err_probe(dev, -ENODEV, "Invalid device ID: %x, expected %x\n",
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regval, ADXL345_DEVID);
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/* Enable measurement mode */
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ret = adxl345_powerup(data->regmap);
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if (ret < 0)
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return dev_err_probe(dev, ret, "Failed to enable measurement mode\n");
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ret = devm_add_action_or_reset(dev, adxl345_powerdown, data->regmap);
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if (ret < 0)
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return ret;
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return devm_iio_device_register(dev, indio_dev);
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}
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EXPORT_SYMBOL_NS_GPL(adxl345_core_probe, IIO_ADXL345);
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MODULE_AUTHOR("Eva Rachel Retuya <eraretuya@gmail.com>");
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MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer core driver");
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MODULE_LICENSE("GPL v2");
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