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
adxl345_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)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
adxl345_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)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
adxl345_write_raw_get_fmt(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,long mask)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
adxl345_powerup(void * regmap)161 static int adxl345_powerup(void *regmap)
162 {
163 return regmap_write(regmap, ADXL345_REG_POWER_CTL, ADXL345_POWER_CTL_MEASURE);
164 }
165
adxl345_powerdown(void * regmap)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 */
adxl345_core_probe(struct device * dev,struct regmap * regmap,int (* setup)(struct device *,struct regmap *))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