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 | #define ADXL345_REG_DEVID 0x00 |
21 | #define ADXL345_REG_OFSX 0x1e |
22 | #define ADXL345_REG_OFSY 0x1f |
23 | #define ADXL345_REG_OFSZ 0x20 |
24 | #define ADXL345_REG_OFS_AXIS(index) (ADXL345_REG_OFSX + (index)) |
25 | #define ADXL345_REG_BW_RATE 0x2C |
26 | #define ADXL345_REG_POWER_CTL 0x2D |
27 | #define ADXL345_REG_DATA_FORMAT 0x31 |
28 | #define ADXL345_REG_DATAX0 0x32 |
29 | #define ADXL345_REG_DATAY0 0x34 |
30 | #define ADXL345_REG_DATAZ0 0x36 |
31 | #define ADXL345_REG_DATA_AXIS(index) \ |
32 | (ADXL345_REG_DATAX0 + (index) * sizeof(__le16)) |
33 | |
34 | #define ADXL345_BW_RATE GENMASK(3, 0) |
35 | #define ADXL345_BASE_RATE_NANO_HZ 97656250LL |
36 | |
37 | #define ADXL345_POWER_CTL_MEASURE BIT(3) |
38 | #define ADXL345_POWER_CTL_STANDBY 0x00 |
39 | |
40 | #define ADXL345_DATA_FORMAT_FULL_RES BIT(3) /* Up to 13-bits resolution */ |
41 | #define ADXL345_DATA_FORMAT_2G 0 |
42 | #define ADXL345_DATA_FORMAT_4G 1 |
43 | #define ADXL345_DATA_FORMAT_8G 2 |
44 | #define ADXL345_DATA_FORMAT_16G 3 |
45 | |
46 | #define ADXL345_DEVID 0xE5 |
47 | |
48 | struct adxl345_data { |
49 | const struct adxl345_chip_info *info; |
50 | struct regmap *regmap; |
51 | u8 data_range; |
52 | }; |
53 | |
54 | #define ADXL345_CHANNEL(index, axis) { \ |
55 | .type = IIO_ACCEL, \ |
56 | .modified = 1, \ |
57 | .channel2 = IIO_MOD_##axis, \ |
58 | .address = index, \ |
59 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ |
60 | BIT(IIO_CHAN_INFO_CALIBBIAS), \ |
61 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ |
62 | BIT(IIO_CHAN_INFO_SAMP_FREQ), \ |
63 | } |
64 | |
65 | static const struct iio_chan_spec adxl345_channels[] = { |
66 | ADXL345_CHANNEL(0, X), |
67 | ADXL345_CHANNEL(1, Y), |
68 | ADXL345_CHANNEL(2, Z), |
69 | }; |
70 | |
71 | static int adxl345_read_raw(struct iio_dev *indio_dev, |
72 | struct iio_chan_spec const *chan, |
73 | int *val, int *val2, long mask) |
74 | { |
75 | struct adxl345_data *data = iio_priv(indio_dev); |
76 | __le16 accel; |
77 | long long samp_freq_nhz; |
78 | unsigned int regval; |
79 | int ret; |
80 | |
81 | switch (mask) { |
82 | case IIO_CHAN_INFO_RAW: |
83 | /* |
84 | * Data is stored in adjacent registers: |
85 | * ADXL345_REG_DATA(X0/Y0/Z0) contain the least significant byte |
86 | * and ADXL345_REG_DATA(X0/Y0/Z0) + 1 the most significant byte |
87 | */ |
88 | ret = regmap_bulk_read(map: data->regmap, |
89 | ADXL345_REG_DATA_AXIS(chan->address), |
90 | val: &accel, val_count: sizeof(accel)); |
91 | if (ret < 0) |
92 | return ret; |
93 | |
94 | *val = sign_extend32(le16_to_cpu(accel), index: 12); |
95 | return IIO_VAL_INT; |
96 | case IIO_CHAN_INFO_SCALE: |
97 | *val = 0; |
98 | *val2 = data->info->uscale; |
99 | return IIO_VAL_INT_PLUS_MICRO; |
100 | case IIO_CHAN_INFO_CALIBBIAS: |
101 | ret = regmap_read(map: data->regmap, |
102 | ADXL345_REG_OFS_AXIS(chan->address), val: ®val); |
103 | if (ret < 0) |
104 | return ret; |
105 | /* |
106 | * 8-bit resolution at +/- 2g, that is 4x accel data scale |
107 | * factor |
108 | */ |
109 | *val = sign_extend32(value: regval, index: 7) * 4; |
110 | |
111 | return IIO_VAL_INT; |
112 | case IIO_CHAN_INFO_SAMP_FREQ: |
113 | ret = regmap_read(map: data->regmap, ADXL345_REG_BW_RATE, val: ®val); |
114 | if (ret < 0) |
115 | return ret; |
116 | |
117 | samp_freq_nhz = ADXL345_BASE_RATE_NANO_HZ << |
118 | (regval & ADXL345_BW_RATE); |
119 | *val = div_s64_rem(dividend: samp_freq_nhz, NANOHZ_PER_HZ, remainder: val2); |
120 | |
121 | return IIO_VAL_INT_PLUS_NANO; |
122 | } |
123 | |
124 | return -EINVAL; |
125 | } |
126 | |
127 | static int adxl345_write_raw(struct iio_dev *indio_dev, |
128 | struct iio_chan_spec const *chan, |
129 | int val, int val2, long mask) |
130 | { |
131 | struct adxl345_data *data = iio_priv(indio_dev); |
132 | s64 n; |
133 | |
134 | switch (mask) { |
135 | case IIO_CHAN_INFO_CALIBBIAS: |
136 | /* |
137 | * 8-bit resolution at +/- 2g, that is 4x accel data scale |
138 | * factor |
139 | */ |
140 | return regmap_write(map: data->regmap, |
141 | ADXL345_REG_OFS_AXIS(chan->address), |
142 | val: val / 4); |
143 | case IIO_CHAN_INFO_SAMP_FREQ: |
144 | n = div_s64(dividend: val * NANOHZ_PER_HZ + val2, |
145 | ADXL345_BASE_RATE_NANO_HZ); |
146 | |
147 | return regmap_update_bits(map: data->regmap, ADXL345_REG_BW_RATE, |
148 | ADXL345_BW_RATE, |
149 | clamp_val(ilog2(n), 0, |
150 | ADXL345_BW_RATE)); |
151 | } |
152 | |
153 | return -EINVAL; |
154 | } |
155 | |
156 | static int adxl345_write_raw_get_fmt(struct iio_dev *indio_dev, |
157 | struct iio_chan_spec const *chan, |
158 | long mask) |
159 | { |
160 | switch (mask) { |
161 | case IIO_CHAN_INFO_CALIBBIAS: |
162 | return IIO_VAL_INT; |
163 | case IIO_CHAN_INFO_SAMP_FREQ: |
164 | return IIO_VAL_INT_PLUS_NANO; |
165 | default: |
166 | return -EINVAL; |
167 | } |
168 | } |
169 | |
170 | static IIO_CONST_ATTR_SAMP_FREQ_AVAIL( |
171 | "0.09765625 0.1953125 0.390625 0.78125 1.5625 3.125 6.25 12.5 25 50 100 200 400 800 1600 3200" |
172 | ); |
173 | |
174 | static struct attribute *adxl345_attrs[] = { |
175 | &iio_const_attr_sampling_frequency_available.dev_attr.attr, |
176 | NULL |
177 | }; |
178 | |
179 | static const struct attribute_group adxl345_attrs_group = { |
180 | .attrs = adxl345_attrs, |
181 | }; |
182 | |
183 | static const struct iio_info adxl345_info = { |
184 | .attrs = &adxl345_attrs_group, |
185 | .read_raw = adxl345_read_raw, |
186 | .write_raw = adxl345_write_raw, |
187 | .write_raw_get_fmt = adxl345_write_raw_get_fmt, |
188 | }; |
189 | |
190 | static int adxl345_powerup(void *regmap) |
191 | { |
192 | return regmap_write(map: regmap, ADXL345_REG_POWER_CTL, ADXL345_POWER_CTL_MEASURE); |
193 | } |
194 | |
195 | static void adxl345_powerdown(void *regmap) |
196 | { |
197 | regmap_write(map: regmap, ADXL345_REG_POWER_CTL, ADXL345_POWER_CTL_STANDBY); |
198 | } |
199 | |
200 | int adxl345_core_probe(struct device *dev, struct regmap *regmap) |
201 | { |
202 | struct adxl345_data *data; |
203 | struct iio_dev *indio_dev; |
204 | u32 regval; |
205 | int ret; |
206 | |
207 | ret = regmap_read(map: regmap, ADXL345_REG_DEVID, val: ®val); |
208 | if (ret < 0) |
209 | return dev_err_probe(dev, err: ret, fmt: "Error reading device ID\n" ); |
210 | |
211 | if (regval != ADXL345_DEVID) |
212 | return dev_err_probe(dev, err: -ENODEV, fmt: "Invalid device ID: %x, expected %x\n" , |
213 | regval, ADXL345_DEVID); |
214 | |
215 | indio_dev = devm_iio_device_alloc(parent: dev, sizeof_priv: sizeof(*data)); |
216 | if (!indio_dev) |
217 | return -ENOMEM; |
218 | |
219 | data = iio_priv(indio_dev); |
220 | data->regmap = regmap; |
221 | /* Enable full-resolution mode */ |
222 | data->data_range = ADXL345_DATA_FORMAT_FULL_RES; |
223 | data->info = device_get_match_data(dev); |
224 | if (!data->info) |
225 | return -ENODEV; |
226 | |
227 | ret = regmap_write(map: data->regmap, ADXL345_REG_DATA_FORMAT, |
228 | val: data->data_range); |
229 | if (ret < 0) |
230 | return dev_err_probe(dev, err: ret, fmt: "Failed to set data range\n" ); |
231 | |
232 | indio_dev->name = data->info->name; |
233 | indio_dev->info = &adxl345_info; |
234 | indio_dev->modes = INDIO_DIRECT_MODE; |
235 | indio_dev->channels = adxl345_channels; |
236 | indio_dev->num_channels = ARRAY_SIZE(adxl345_channels); |
237 | |
238 | /* Enable measurement mode */ |
239 | ret = adxl345_powerup(regmap: data->regmap); |
240 | if (ret < 0) |
241 | return dev_err_probe(dev, err: ret, fmt: "Failed to enable measurement mode\n" ); |
242 | |
243 | ret = devm_add_action_or_reset(dev, adxl345_powerdown, data->regmap); |
244 | if (ret < 0) |
245 | return ret; |
246 | |
247 | return devm_iio_device_register(dev, indio_dev); |
248 | } |
249 | EXPORT_SYMBOL_NS_GPL(adxl345_core_probe, IIO_ADXL345); |
250 | |
251 | MODULE_AUTHOR("Eva Rachel Retuya <eraretuya@gmail.com>" ); |
252 | MODULE_DESCRIPTION("ADXL345 3-Axis Digital Accelerometer core driver" ); |
253 | MODULE_LICENSE("GPL v2" ); |
254 | |