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39631b5f PM |
1 | /* |
2 | * mag3110.c - Support for Freescale MAG3110 magnetometer sensor | |
3 | * | |
4 | * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net> | |
5 | * | |
6 | * This file is subject to the terms and conditions of version 2 of | |
7 | * the GNU General Public License. See the file COPYING in the main | |
8 | * directory of this archive for more details. | |
9 | * | |
10 | * (7-bit I2C slave address 0x0e) | |
11 | * | |
12 | * TODO: irq, user offset, oversampling, continuous mode | |
13 | */ | |
14 | ||
15 | #include <linux/module.h> | |
16 | #include <linux/i2c.h> | |
17 | #include <linux/iio/iio.h> | |
18 | #include <linux/iio/sysfs.h> | |
19 | #include <linux/iio/trigger_consumer.h> | |
20 | #include <linux/iio/buffer.h> | |
21 | #include <linux/iio/triggered_buffer.h> | |
22 | #include <linux/delay.h> | |
23 | ||
24 | #define MAG3110_STATUS 0x00 | |
25 | #define MAG3110_OUT_X 0x01 /* MSB first */ | |
26 | #define MAG3110_OUT_Y 0x03 | |
27 | #define MAG3110_OUT_Z 0x05 | |
28 | #define MAG3110_WHO_AM_I 0x07 | |
29 | #define MAG3110_OFF_X 0x09 /* MSB first */ | |
30 | #define MAG3110_OFF_Y 0x0b | |
31 | #define MAG3110_OFF_Z 0x0d | |
32 | #define MAG3110_DIE_TEMP 0x0f | |
33 | #define MAG3110_CTRL_REG1 0x10 | |
34 | #define MAG3110_CTRL_REG2 0x11 | |
35 | ||
36 | #define MAG3110_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0)) | |
37 | ||
38 | #define MAG3110_CTRL_DR_MASK (BIT(7) | BIT(6) | BIT(5)) | |
39 | #define MAG3110_CTRL_DR_SHIFT 5 | |
40 | #define MAG3110_CTRL_DR_DEFAULT 0 | |
41 | ||
42 | #define MAG3110_CTRL_TM BIT(1) /* trigger single measurement */ | |
43 | #define MAG3110_CTRL_AC BIT(0) /* continuous measurements */ | |
44 | ||
45 | #define MAG3110_CTRL_AUTO_MRST_EN BIT(7) /* magnetic auto-reset */ | |
46 | #define MAG3110_CTRL_RAW BIT(5) /* measurements not user-offset corrected */ | |
47 | ||
48 | #define MAG3110_DEVICE_ID 0xc4 | |
49 | ||
50 | /* Each client has this additional data */ | |
51 | struct mag3110_data { | |
52 | struct i2c_client *client; | |
53 | struct mutex lock; | |
54 | u8 ctrl_reg1; | |
55 | }; | |
56 | ||
57 | static int mag3110_request(struct mag3110_data *data) | |
58 | { | |
59 | int ret, tries = 150; | |
60 | ||
61 | /* trigger measurement */ | |
62 | ret = i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1, | |
63 | data->ctrl_reg1 | MAG3110_CTRL_TM); | |
64 | if (ret < 0) | |
65 | return ret; | |
66 | ||
67 | while (tries-- > 0) { | |
68 | ret = i2c_smbus_read_byte_data(data->client, MAG3110_STATUS); | |
69 | if (ret < 0) | |
70 | return ret; | |
71 | /* wait for data ready */ | |
72 | if ((ret & MAG3110_STATUS_DRDY) == MAG3110_STATUS_DRDY) | |
73 | break; | |
74 | msleep(20); | |
75 | } | |
76 | ||
77 | if (tries < 0) { | |
78 | dev_err(&data->client->dev, "data not ready\n"); | |
79 | return -EIO; | |
80 | } | |
81 | ||
82 | return 0; | |
83 | } | |
84 | ||
85 | static int mag3110_read(struct mag3110_data *data, __be16 buf[3]) | |
86 | { | |
87 | int ret; | |
88 | ||
89 | mutex_lock(&data->lock); | |
90 | ret = mag3110_request(data); | |
91 | if (ret < 0) { | |
92 | mutex_unlock(&data->lock); | |
93 | return ret; | |
94 | } | |
95 | ret = i2c_smbus_read_i2c_block_data(data->client, | |
96 | MAG3110_OUT_X, 3 * sizeof(__be16), (u8 *) buf); | |
97 | mutex_unlock(&data->lock); | |
98 | ||
99 | return ret; | |
100 | } | |
101 | ||
102 | static ssize_t mag3110_show_int_plus_micros(char *buf, | |
103 | const int (*vals)[2], int n) | |
104 | { | |
105 | size_t len = 0; | |
106 | ||
107 | while (n-- > 0) | |
108 | len += scnprintf(buf + len, PAGE_SIZE - len, | |
71bd8945 | 109 | "%d.%06d ", vals[n][0], vals[n][1]); |
39631b5f PM |
110 | |
111 | /* replace trailing space by newline */ | |
112 | buf[len - 1] = '\n'; | |
113 | ||
114 | return len; | |
115 | } | |
116 | ||
117 | static int mag3110_get_int_plus_micros_index(const int (*vals)[2], int n, | |
118 | int val, int val2) | |
119 | { | |
120 | while (n-- > 0) | |
121 | if (val == vals[n][0] && val2 == vals[n][1]) | |
122 | return n; | |
123 | ||
124 | return -EINVAL; | |
125 | } | |
126 | ||
127 | static const int mag3110_samp_freq[8][2] = { | |
128 | {80, 0}, {40, 0}, {20, 0}, {10, 0}, {5, 0}, {2, 500000}, | |
129 | {1, 250000}, {0, 625000} | |
130 | }; | |
131 | ||
132 | static ssize_t mag3110_show_samp_freq_avail(struct device *dev, | |
133 | struct device_attribute *attr, char *buf) | |
134 | { | |
135 | return mag3110_show_int_plus_micros(buf, mag3110_samp_freq, 8); | |
136 | } | |
137 | ||
138 | static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(mag3110_show_samp_freq_avail); | |
139 | ||
140 | static int mag3110_get_samp_freq_index(struct mag3110_data *data, | |
141 | int val, int val2) | |
142 | { | |
143 | return mag3110_get_int_plus_micros_index(mag3110_samp_freq, 8, val, | |
144 | val2); | |
145 | } | |
146 | ||
147 | static int mag3110_read_raw(struct iio_dev *indio_dev, | |
148 | struct iio_chan_spec const *chan, | |
149 | int *val, int *val2, long mask) | |
150 | { | |
151 | struct mag3110_data *data = iio_priv(indio_dev); | |
152 | __be16 buffer[3]; | |
153 | int i, ret; | |
154 | ||
155 | switch (mask) { | |
156 | case IIO_CHAN_INFO_RAW: | |
f25330f6 PM |
157 | if (iio_buffer_enabled(indio_dev)) |
158 | return -EBUSY; | |
159 | ||
39631b5f PM |
160 | switch (chan->type) { |
161 | case IIO_MAGN: /* in 0.1 uT / LSB */ | |
162 | ret = mag3110_read(data, buffer); | |
163 | if (ret < 0) | |
164 | return ret; | |
165 | *val = sign_extend32( | |
166 | be16_to_cpu(buffer[chan->scan_index]), 15); | |
167 | return IIO_VAL_INT; | |
168 | case IIO_TEMP: /* in 1 C / LSB */ | |
169 | mutex_lock(&data->lock); | |
170 | ret = mag3110_request(data); | |
171 | if (ret < 0) { | |
172 | mutex_unlock(&data->lock); | |
173 | return ret; | |
174 | } | |
175 | ret = i2c_smbus_read_byte_data(data->client, | |
176 | MAG3110_DIE_TEMP); | |
177 | mutex_unlock(&data->lock); | |
178 | if (ret < 0) | |
179 | return ret; | |
180 | *val = sign_extend32(ret, 7); | |
181 | return IIO_VAL_INT; | |
182 | default: | |
183 | return -EINVAL; | |
184 | } | |
185 | case IIO_CHAN_INFO_SCALE: | |
f9279d3a PM |
186 | switch (chan->type) { |
187 | case IIO_MAGN: | |
188 | *val = 0; | |
189 | *val2 = 1000; | |
190 | return IIO_VAL_INT_PLUS_MICRO; | |
191 | case IIO_TEMP: | |
192 | *val = 1000; | |
193 | return IIO_VAL_INT; | |
194 | default: | |
195 | return -EINVAL; | |
196 | } | |
39631b5f PM |
197 | case IIO_CHAN_INFO_SAMP_FREQ: |
198 | i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT; | |
199 | *val = mag3110_samp_freq[i][0]; | |
200 | *val2 = mag3110_samp_freq[i][1]; | |
201 | return IIO_VAL_INT_PLUS_MICRO; | |
0828eddc PM |
202 | case IIO_CHAN_INFO_CALIBBIAS: |
203 | ret = i2c_smbus_read_word_swapped(data->client, | |
204 | MAG3110_OFF_X + 2 * chan->scan_index); | |
205 | if (ret < 0) | |
206 | return ret; | |
207 | *val = sign_extend32(ret >> 1, 14); | |
208 | return IIO_VAL_INT; | |
39631b5f PM |
209 | } |
210 | return -EINVAL; | |
211 | } | |
212 | ||
213 | static int mag3110_write_raw(struct iio_dev *indio_dev, | |
214 | struct iio_chan_spec const *chan, | |
215 | int val, int val2, long mask) | |
216 | { | |
217 | struct mag3110_data *data = iio_priv(indio_dev); | |
218 | int rate; | |
219 | ||
f25330f6 PM |
220 | if (iio_buffer_enabled(indio_dev)) |
221 | return -EBUSY; | |
222 | ||
39631b5f PM |
223 | switch (mask) { |
224 | case IIO_CHAN_INFO_SAMP_FREQ: | |
225 | rate = mag3110_get_samp_freq_index(data, val, val2); | |
226 | if (rate < 0) | |
227 | return -EINVAL; | |
228 | ||
229 | data->ctrl_reg1 &= ~MAG3110_CTRL_DR_MASK; | |
230 | data->ctrl_reg1 |= rate << MAG3110_CTRL_DR_SHIFT; | |
231 | return i2c_smbus_write_byte_data(data->client, | |
232 | MAG3110_CTRL_REG1, data->ctrl_reg1); | |
0828eddc PM |
233 | case IIO_CHAN_INFO_CALIBBIAS: |
234 | if (val < -10000 || val > 10000) | |
235 | return -EINVAL; | |
236 | return i2c_smbus_write_word_swapped(data->client, | |
237 | MAG3110_OFF_X + 2 * chan->scan_index, val << 1); | |
39631b5f PM |
238 | default: |
239 | return -EINVAL; | |
240 | } | |
241 | } | |
242 | ||
243 | static irqreturn_t mag3110_trigger_handler(int irq, void *p) | |
244 | { | |
245 | struct iio_poll_func *pf = p; | |
246 | struct iio_dev *indio_dev = pf->indio_dev; | |
247 | struct mag3110_data *data = iio_priv(indio_dev); | |
248 | u8 buffer[16]; /* 3 16-bit channels + 1 byte temp + padding + ts */ | |
249 | int ret; | |
250 | ||
251 | ret = mag3110_read(data, (__be16 *) buffer); | |
252 | if (ret < 0) | |
253 | goto done; | |
254 | ||
255 | if (test_bit(3, indio_dev->active_scan_mask)) { | |
256 | ret = i2c_smbus_read_byte_data(data->client, | |
257 | MAG3110_DIE_TEMP); | |
258 | if (ret < 0) | |
259 | goto done; | |
260 | buffer[6] = ret; | |
261 | } | |
262 | ||
263 | iio_push_to_buffers_with_timestamp(indio_dev, buffer, | |
264 | iio_get_time_ns()); | |
265 | ||
266 | done: | |
267 | iio_trigger_notify_done(indio_dev->trig); | |
268 | return IRQ_HANDLED; | |
269 | } | |
270 | ||
271 | #define MAG3110_CHANNEL(axis, idx) { \ | |
272 | .type = IIO_MAGN, \ | |
273 | .modified = 1, \ | |
274 | .channel2 = IIO_MOD_##axis, \ | |
0828eddc PM |
275 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ |
276 | BIT(IIO_CHAN_INFO_CALIBBIAS), \ | |
39631b5f PM |
277 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \ |
278 | BIT(IIO_CHAN_INFO_SCALE), \ | |
279 | .scan_index = idx, \ | |
911bdc68 PM |
280 | .scan_type = { \ |
281 | .sign = 's', \ | |
282 | .realbits = 16, \ | |
283 | .storagebits = 16, \ | |
284 | .endianness = IIO_BE, \ | |
285 | }, \ | |
39631b5f PM |
286 | } |
287 | ||
288 | static const struct iio_chan_spec mag3110_channels[] = { | |
289 | MAG3110_CHANNEL(X, 0), | |
290 | MAG3110_CHANNEL(Y, 1), | |
291 | MAG3110_CHANNEL(Z, 2), | |
292 | { | |
293 | .type = IIO_TEMP, | |
f9279d3a PM |
294 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
295 | BIT(IIO_CHAN_INFO_SCALE), | |
39631b5f | 296 | .scan_index = 3, |
e5687979 JC |
297 | .scan_type = { |
298 | .sign = 's', | |
299 | .realbits = 8, | |
300 | .storagebits = 8, | |
301 | }, | |
39631b5f PM |
302 | }, |
303 | IIO_CHAN_SOFT_TIMESTAMP(4), | |
304 | }; | |
305 | ||
306 | static struct attribute *mag3110_attributes[] = { | |
307 | &iio_dev_attr_sampling_frequency_available.dev_attr.attr, | |
308 | NULL | |
309 | }; | |
310 | ||
311 | static const struct attribute_group mag3110_group = { | |
312 | .attrs = mag3110_attributes, | |
313 | }; | |
314 | ||
315 | static const struct iio_info mag3110_info = { | |
316 | .attrs = &mag3110_group, | |
317 | .read_raw = &mag3110_read_raw, | |
318 | .write_raw = &mag3110_write_raw, | |
319 | .driver_module = THIS_MODULE, | |
320 | }; | |
321 | ||
322 | static const unsigned long mag3110_scan_masks[] = {0x7, 0xf, 0}; | |
323 | ||
66687e6a CO |
324 | static int mag3110_standby(struct mag3110_data *data) |
325 | { | |
326 | return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1, | |
327 | data->ctrl_reg1 & ~MAG3110_CTRL_AC); | |
328 | } | |
329 | ||
39631b5f PM |
330 | static int mag3110_probe(struct i2c_client *client, |
331 | const struct i2c_device_id *id) | |
332 | { | |
333 | struct mag3110_data *data; | |
334 | struct iio_dev *indio_dev; | |
335 | int ret; | |
336 | ||
337 | ret = i2c_smbus_read_byte_data(client, MAG3110_WHO_AM_I); | |
338 | if (ret < 0) | |
339 | return ret; | |
340 | if (ret != MAG3110_DEVICE_ID) | |
341 | return -ENODEV; | |
342 | ||
343 | indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); | |
344 | if (!indio_dev) | |
345 | return -ENOMEM; | |
346 | ||
347 | data = iio_priv(indio_dev); | |
348 | data->client = client; | |
349 | mutex_init(&data->lock); | |
350 | ||
351 | i2c_set_clientdata(client, indio_dev); | |
352 | indio_dev->info = &mag3110_info; | |
353 | indio_dev->name = id->name; | |
354 | indio_dev->dev.parent = &client->dev; | |
355 | indio_dev->modes = INDIO_DIRECT_MODE; | |
356 | indio_dev->channels = mag3110_channels; | |
357 | indio_dev->num_channels = ARRAY_SIZE(mag3110_channels); | |
358 | indio_dev->available_scan_masks = mag3110_scan_masks; | |
359 | ||
6584891b | 360 | data->ctrl_reg1 = MAG3110_CTRL_DR_DEFAULT << MAG3110_CTRL_DR_SHIFT; |
39631b5f PM |
361 | ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG1, |
362 | data->ctrl_reg1); | |
363 | if (ret < 0) | |
364 | return ret; | |
365 | ||
366 | ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG2, | |
0828eddc | 367 | MAG3110_CTRL_AUTO_MRST_EN); |
39631b5f | 368 | if (ret < 0) |
66687e6a | 369 | goto standby_on_error; |
39631b5f PM |
370 | |
371 | ret = iio_triggered_buffer_setup(indio_dev, NULL, | |
372 | mag3110_trigger_handler, NULL); | |
373 | if (ret < 0) | |
66687e6a | 374 | goto standby_on_error; |
39631b5f PM |
375 | |
376 | ret = iio_device_register(indio_dev); | |
377 | if (ret < 0) | |
378 | goto buffer_cleanup; | |
379 | return 0; | |
380 | ||
381 | buffer_cleanup: | |
382 | iio_triggered_buffer_cleanup(indio_dev); | |
66687e6a CO |
383 | standby_on_error: |
384 | mag3110_standby(iio_priv(indio_dev)); | |
39631b5f PM |
385 | return ret; |
386 | } | |
387 | ||
39631b5f PM |
388 | static int mag3110_remove(struct i2c_client *client) |
389 | { | |
390 | struct iio_dev *indio_dev = i2c_get_clientdata(client); | |
391 | ||
392 | iio_device_unregister(indio_dev); | |
393 | iio_triggered_buffer_cleanup(indio_dev); | |
394 | mag3110_standby(iio_priv(indio_dev)); | |
395 | ||
396 | return 0; | |
397 | } | |
398 | ||
399 | #ifdef CONFIG_PM_SLEEP | |
400 | static int mag3110_suspend(struct device *dev) | |
401 | { | |
402 | return mag3110_standby(iio_priv(i2c_get_clientdata( | |
403 | to_i2c_client(dev)))); | |
404 | } | |
405 | ||
406 | static int mag3110_resume(struct device *dev) | |
407 | { | |
408 | struct mag3110_data *data = iio_priv(i2c_get_clientdata( | |
409 | to_i2c_client(dev))); | |
410 | ||
411 | return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1, | |
412 | data->ctrl_reg1); | |
413 | } | |
414 | ||
415 | static SIMPLE_DEV_PM_OPS(mag3110_pm_ops, mag3110_suspend, mag3110_resume); | |
416 | #define MAG3110_PM_OPS (&mag3110_pm_ops) | |
417 | #else | |
418 | #define MAG3110_PM_OPS NULL | |
419 | #endif | |
420 | ||
421 | static const struct i2c_device_id mag3110_id[] = { | |
422 | { "mag3110", 0 }, | |
423 | { } | |
424 | }; | |
425 | MODULE_DEVICE_TABLE(i2c, mag3110_id); | |
426 | ||
427 | static struct i2c_driver mag3110_driver = { | |
428 | .driver = { | |
429 | .name = "mag3110", | |
430 | .pm = MAG3110_PM_OPS, | |
431 | }, | |
432 | .probe = mag3110_probe, | |
433 | .remove = mag3110_remove, | |
434 | .id_table = mag3110_id, | |
435 | }; | |
436 | module_i2c_driver(mag3110_driver); | |
437 | ||
438 | MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>"); | |
439 | MODULE_DESCRIPTION("Freescale MAG3110 magnetometer driver"); | |
440 | MODULE_LICENSE("GPL"); |