1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * ADXL345 3-Axis Digital Accelerometer IIO core driver 4 * 5 * Copyright (c) 2017 Eva Rachel Retuya <eraretuya@gmail.com> 6 * 7 * Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ADXL345.pdf 8 */ 9 10 #include <linux/module.h> 11 #include <linux/property.h> 12 #include <linux/regmap.h> 13 #include <linux/units.h> 14 15 #include <linux/iio/iio.h> 16 #include <linux/iio/sysfs.h> 17 18 #include "adxl345.h" 19 20 struct adxl345_data { 21 const struct adxl345_chip_info *info; 22 struct regmap *regmap; 23 }; 24 25 #define ADXL345_CHANNEL(index, axis) { \ 26 .type = IIO_ACCEL, \ 27 .modified = 1, \ 28 .channel2 = IIO_MOD_##axis, \ 29 .address = index, \ 30 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ 31 BIT(IIO_CHAN_INFO_CALIBBIAS), \ 32 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ 33 BIT(IIO_CHAN_INFO_SAMP_FREQ), \ 34 } 35 36 static const struct iio_chan_spec adxl345_channels[] = { 37 ADXL345_CHANNEL(0, X), 38 ADXL345_CHANNEL(1, Y), 39 ADXL345_CHANNEL(2, Z), 40 }; 41 42 static int adxl345_read_raw(struct iio_dev *indio_dev, 43 struct iio_chan_spec const *chan, 44 int *val, int *val2, long mask) 45 { 46 struct adxl345_data *data = iio_priv(indio_dev); 47 __le16 accel; 48 long long samp_freq_nhz; 49 unsigned int regval; 50 int ret; 51 52 switch (mask) { 53 case IIO_CHAN_INFO_RAW: 54 /* 55 * Data is stored in adjacent registers: 56 * ADXL345_REG_DATA(X0/Y0/Z0) contain the least significant byte 57 * and ADXL345_REG_DATA(X0/Y0/Z0) + 1 the most significant byte 58 */ 59 ret = regmap_bulk_read(data->regmap, 60 ADXL345_REG_DATA_AXIS(chan->address), 61 &accel, sizeof(accel)); 62 if (ret < 0) 63 return ret; 64 65 *val = sign_extend32(le16_to_cpu(accel), 12); 66 return IIO_VAL_INT; 67 case IIO_CHAN_INFO_SCALE: 68 *val = 0; 69 *val2 = data->info->uscale; 70 return IIO_VAL_INT_PLUS_MICRO; 71 case IIO_CHAN_INFO_CALIBBIAS: 72 ret = regmap_read(data->regmap, 73 ADXL345_REG_OFS_AXIS(chan->address), ®val); 74 if (ret < 0) 75 return ret; 76 /* 77 * 8-bit resolution at +/- 2g, that is 4x accel data scale 78 * factor 79 */ 80 *val = sign_extend32(regval, 7) * 4; 81 82 return IIO_VAL_INT; 83 case IIO_CHAN_INFO_SAMP_FREQ: 84 ret = regmap_read(data->regmap, ADXL345_REG_BW_RATE, ®val); 85 if (ret < 0) 86 return ret; 87 88 samp_freq_nhz = ADXL345_BASE_RATE_NANO_HZ << 89 (regval & ADXL345_BW_RATE); 90 *val = div_s64_rem(samp_freq_nhz, NANOHZ_PER_HZ, val2); 91 92 return IIO_VAL_INT_PLUS_NANO; 93 } 94 95 return -EINVAL; 96 } 97 98 static int adxl345_write_raw(struct iio_dev *indio_dev, 99 struct iio_chan_spec const *chan, 100 int val, int val2, long mask) 101 { 102 struct adxl345_data *data = iio_priv(indio_dev); 103 s64 n; 104 105 switch (mask) { 106 case IIO_CHAN_INFO_CALIBBIAS: 107 /* 108 * 8-bit resolution at +/- 2g, that is 4x accel data scale 109 * factor 110 */ 111 return regmap_write(data->regmap, 112 ADXL345_REG_OFS_AXIS(chan->address), 113 val / 4); 114 case IIO_CHAN_INFO_SAMP_FREQ: 115 n = div_s64(val * NANOHZ_PER_HZ + val2, 116 ADXL345_BASE_RATE_NANO_HZ); 117 118 return regmap_update_bits(data->regmap, ADXL345_REG_BW_RATE, 119 ADXL345_BW_RATE, 120 clamp_val(ilog2(n), 0, 121 ADXL345_BW_RATE)); 122 } 123 124 return -EINVAL; 125 } 126 127 static int adxl345_write_raw_get_fmt(struct iio_dev *indio_dev, 128 struct iio_chan_spec const *chan, 129 long mask) 130 { 131 switch (mask) { 132 case IIO_CHAN_INFO_CALIBBIAS: 133 return IIO_VAL_INT; 134 case IIO_CHAN_INFO_SAMP_FREQ: 135 return IIO_VAL_INT_PLUS_NANO; 136 default: 137 return -EINVAL; 138 } 139 } 140 141 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL( 142 "0.09765625 0.1953125 0.390625 0.78125 1.5625 3.125 6.25 12.5 25 50 100 200 400 800 1600 3200" 143 ); 144 145 static struct attribute *adxl345_attrs[] = { 146 &iio_const_attr_sampling_frequency_available.dev_attr.attr, 147 NULL 148 }; 149 150 static const struct attribute_group adxl345_attrs_group = { 151 .attrs = adxl345_attrs, 152 }; 153 154 static const struct iio_info adxl345_info = { 155 .attrs = &adxl345_attrs_group, 156 .read_raw = adxl345_read_raw, 157 .write_raw = adxl345_write_raw, 158 .write_raw_get_fmt = adxl345_write_raw_get_fmt, 159 }; 160 161 static int adxl345_powerup(void *regmap) 162 { 163 return regmap_write(regmap, ADXL345_REG_POWER_CTL, ADXL345_POWER_CTL_MEASURE); 164 } 165 166 static void adxl345_powerdown(void *regmap) 167 { 168 regmap_write(regmap, ADXL345_REG_POWER_CTL, ADXL345_POWER_CTL_STANDBY); 169 } 170 171 /** 172 * adxl345_core_probe() - probe and setup for the adxl345 accelerometer, 173 * also covers the adlx375 accelerometer 174 * @dev: Driver model representation of the device 175 * @regmap: Regmap instance for the device 176 * @setup: Setup routine to be executed right before the standard device 177 * setup 178 * 179 * Return: 0 on success, negative errno on error 180 */ 181 int adxl345_core_probe(struct device *dev, struct regmap *regmap, 182 int (*setup)(struct device*, struct regmap*)) 183 { 184 struct adxl345_data *data; 185 struct iio_dev *indio_dev; 186 u32 regval; 187 unsigned int data_format_mask = (ADXL345_DATA_FORMAT_RANGE | 188 ADXL345_DATA_FORMAT_JUSTIFY | 189 ADXL345_DATA_FORMAT_FULL_RES | 190 ADXL345_DATA_FORMAT_SELF_TEST); 191 int ret; 192 193 indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); 194 if (!indio_dev) 195 return -ENOMEM; 196 197 data = iio_priv(indio_dev); 198 data->regmap = regmap; 199 data->info = device_get_match_data(dev); 200 if (!data->info) 201 return -ENODEV; 202 203 indio_dev->name = data->info->name; 204 indio_dev->info = &adxl345_info; 205 indio_dev->modes = INDIO_DIRECT_MODE; 206 indio_dev->channels = adxl345_channels; 207 indio_dev->num_channels = ARRAY_SIZE(adxl345_channels); 208 209 if (setup) { 210 /* Perform optional initial bus specific configuration */ 211 ret = setup(dev, data->regmap); 212 if (ret) 213 return ret; 214 215 /* Enable full-resolution mode */ 216 ret = regmap_update_bits(data->regmap, ADXL345_REG_DATA_FORMAT, 217 data_format_mask, 218 ADXL345_DATA_FORMAT_FULL_RES); 219 if (ret) 220 return dev_err_probe(dev, ret, 221 "Failed to set data range\n"); 222 223 } else { 224 /* Enable full-resolution mode (init all data_format bits) */ 225 ret = regmap_write(data->regmap, ADXL345_REG_DATA_FORMAT, 226 ADXL345_DATA_FORMAT_FULL_RES); 227 if (ret) 228 return dev_err_probe(dev, ret, 229 "Failed to set data range\n"); 230 } 231 232 ret = regmap_read(data->regmap, ADXL345_REG_DEVID, ®val); 233 if (ret < 0) 234 return dev_err_probe(dev, ret, "Error reading device ID\n"); 235 236 if (regval != ADXL345_DEVID) 237 return dev_err_probe(dev, -ENODEV, "Invalid device ID: %x, expected %x\n", 238 regval, ADXL345_DEVID); 239 240 /* Enable measurement mode */ 241 ret = adxl345_powerup(data->regmap); 242 if (ret < 0) 243 return dev_err_probe(dev, ret, "Failed to enable measurement mode\n"); 244 245 ret = devm_add_action_or_reset(dev, adxl345_powerdown, data->regmap); 246 if (ret < 0) 247 return ret; 248 249 return devm_iio_device_register(dev, indio_dev); 250 } 251 EXPORT_SYMBOL_NS_GPL(adxl345_core_probe, IIO_ADXL345); 252 253 MODULE_AUTHOR("Eva Rachel Retuya <eraretuya@gmail.com>"); 254 MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer core driver"); 255 MODULE_LICENSE("GPL v2"); 256