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287 lines
7.3 KiB
287 lines
7.3 KiB
// 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 <[email protected]> |
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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/iio/iio.h> |
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#include <linux/iio/sysfs.h> |
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#include "adxl345.h" |
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#define ADXL345_REG_DEVID 0x00 |
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#define ADXL345_REG_OFSX 0x1e |
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#define ADXL345_REG_OFSY 0x1f |
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#define ADXL345_REG_OFSZ 0x20 |
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#define ADXL345_REG_OFS_AXIS(index) (ADXL345_REG_OFSX + (index)) |
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#define ADXL345_REG_BW_RATE 0x2C |
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#define ADXL345_REG_POWER_CTL 0x2D |
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#define ADXL345_REG_DATA_FORMAT 0x31 |
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#define ADXL345_REG_DATAX0 0x32 |
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#define ADXL345_REG_DATAY0 0x34 |
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#define ADXL345_REG_DATAZ0 0x36 |
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#define ADXL345_REG_DATA_AXIS(index) \ |
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(ADXL345_REG_DATAX0 + (index) * sizeof(__le16)) |
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#define ADXL345_BW_RATE GENMASK(3, 0) |
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#define ADXL345_BASE_RATE_NANO_HZ 97656250LL |
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#define NHZ_PER_HZ 1000000000LL |
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#define ADXL345_POWER_CTL_MEASURE BIT(3) |
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#define ADXL345_POWER_CTL_STANDBY 0x00 |
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#define ADXL345_DATA_FORMAT_FULL_RES BIT(3) /* Up to 13-bits resolution */ |
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#define ADXL345_DATA_FORMAT_2G 0 |
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#define ADXL345_DATA_FORMAT_4G 1 |
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#define ADXL345_DATA_FORMAT_8G 2 |
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#define ADXL345_DATA_FORMAT_16G 3 |
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#define ADXL345_DEVID 0xE5 |
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/* |
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* In full-resolution mode, scale factor is maintained at ~4 mg/LSB |
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* in all g ranges. |
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* |
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* At +/- 16g with 13-bit resolution, scale is computed as: |
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* (16 + 16) * 9.81 / (2^13 - 1) = 0.0383 |
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*/ |
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static const int adxl345_uscale = 38300; |
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/* |
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* The Datasheet lists a resolution of Resolution is ~49 mg per LSB. That's |
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* ~480mm/s**2 per LSB. |
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*/ |
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static const int adxl375_uscale = 480000; |
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struct adxl345_data { |
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struct regmap *regmap; |
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u8 data_range; |
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enum adxl345_device_type type; |
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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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switch (data->type) { |
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case ADXL345: |
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*val2 = adxl345_uscale; |
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break; |
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case ADXL375: |
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*val2 = adxl375_uscale; |
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break; |
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} |
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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, NHZ_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 * NHZ_PER_HZ + val2, 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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int adxl345_core_probe(struct device *dev, struct regmap *regmap) |
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{ |
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enum adxl345_device_type type; |
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struct adxl345_data *data; |
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struct iio_dev *indio_dev; |
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const char *name; |
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u32 regval; |
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int ret; |
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type = (uintptr_t)device_get_match_data(dev); |
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switch (type) { |
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case ADXL345: |
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name = "adxl345"; |
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break; |
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case ADXL375: |
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name = "adxl375"; |
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break; |
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default: |
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return -EINVAL; |
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} |
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ret = regmap_read(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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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->type = type; |
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/* Enable full-resolution mode */ |
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data->data_range = ADXL345_DATA_FORMAT_FULL_RES; |
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ret = regmap_write(data->regmap, ADXL345_REG_DATA_FORMAT, |
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data->data_range); |
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if (ret < 0) |
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return dev_err_probe(dev, ret, "Failed to set data range\n"); |
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indio_dev->name = 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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/* 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 <[email protected]>"); |
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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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