Commit | Line | Data |
---|---|---|
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, | |
109 | "%d.%d ", vals[n][0], vals[n][1]); | |
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: | |
157 | switch (chan->type) { | |
158 | case IIO_MAGN: /* in 0.1 uT / LSB */ | |
159 | ret = mag3110_read(data, buffer); | |
160 | if (ret < 0) | |
161 | return ret; | |
162 | *val = sign_extend32( | |
163 | be16_to_cpu(buffer[chan->scan_index]), 15); | |
164 | return IIO_VAL_INT; | |
165 | case IIO_TEMP: /* in 1 C / LSB */ | |
166 | mutex_lock(&data->lock); | |
167 | ret = mag3110_request(data); | |
168 | if (ret < 0) { | |
169 | mutex_unlock(&data->lock); | |
170 | return ret; | |
171 | } | |
172 | ret = i2c_smbus_read_byte_data(data->client, | |
173 | MAG3110_DIE_TEMP); | |
174 | mutex_unlock(&data->lock); | |
175 | if (ret < 0) | |
176 | return ret; | |
177 | *val = sign_extend32(ret, 7); | |
178 | return IIO_VAL_INT; | |
179 | default: | |
180 | return -EINVAL; | |
181 | } | |
182 | case IIO_CHAN_INFO_SCALE: | |
183 | *val = 0; | |
184 | *val2 = 1000; | |
185 | return IIO_VAL_INT_PLUS_MICRO; | |
186 | case IIO_CHAN_INFO_SAMP_FREQ: | |
187 | i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT; | |
188 | *val = mag3110_samp_freq[i][0]; | |
189 | *val2 = mag3110_samp_freq[i][1]; | |
190 | return IIO_VAL_INT_PLUS_MICRO; | |
191 | } | |
192 | return -EINVAL; | |
193 | } | |
194 | ||
195 | static int mag3110_write_raw(struct iio_dev *indio_dev, | |
196 | struct iio_chan_spec const *chan, | |
197 | int val, int val2, long mask) | |
198 | { | |
199 | struct mag3110_data *data = iio_priv(indio_dev); | |
200 | int rate; | |
201 | ||
202 | switch (mask) { | |
203 | case IIO_CHAN_INFO_SAMP_FREQ: | |
204 | rate = mag3110_get_samp_freq_index(data, val, val2); | |
205 | if (rate < 0) | |
206 | return -EINVAL; | |
207 | ||
208 | data->ctrl_reg1 &= ~MAG3110_CTRL_DR_MASK; | |
209 | data->ctrl_reg1 |= rate << MAG3110_CTRL_DR_SHIFT; | |
210 | return i2c_smbus_write_byte_data(data->client, | |
211 | MAG3110_CTRL_REG1, data->ctrl_reg1); | |
212 | default: | |
213 | return -EINVAL; | |
214 | } | |
215 | } | |
216 | ||
217 | static irqreturn_t mag3110_trigger_handler(int irq, void *p) | |
218 | { | |
219 | struct iio_poll_func *pf = p; | |
220 | struct iio_dev *indio_dev = pf->indio_dev; | |
221 | struct mag3110_data *data = iio_priv(indio_dev); | |
222 | u8 buffer[16]; /* 3 16-bit channels + 1 byte temp + padding + ts */ | |
223 | int ret; | |
224 | ||
225 | ret = mag3110_read(data, (__be16 *) buffer); | |
226 | if (ret < 0) | |
227 | goto done; | |
228 | ||
229 | if (test_bit(3, indio_dev->active_scan_mask)) { | |
230 | ret = i2c_smbus_read_byte_data(data->client, | |
231 | MAG3110_DIE_TEMP); | |
232 | if (ret < 0) | |
233 | goto done; | |
234 | buffer[6] = ret; | |
235 | } | |
236 | ||
237 | iio_push_to_buffers_with_timestamp(indio_dev, buffer, | |
238 | iio_get_time_ns()); | |
239 | ||
240 | done: | |
241 | iio_trigger_notify_done(indio_dev->trig); | |
242 | return IRQ_HANDLED; | |
243 | } | |
244 | ||
245 | #define MAG3110_CHANNEL(axis, idx) { \ | |
246 | .type = IIO_MAGN, \ | |
247 | .modified = 1, \ | |
248 | .channel2 = IIO_MOD_##axis, \ | |
249 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ | |
250 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \ | |
251 | BIT(IIO_CHAN_INFO_SCALE), \ | |
252 | .scan_index = idx, \ | |
253 | .scan_type = IIO_ST('s', 16, 16, IIO_BE), \ | |
254 | } | |
255 | ||
256 | static const struct iio_chan_spec mag3110_channels[] = { | |
257 | MAG3110_CHANNEL(X, 0), | |
258 | MAG3110_CHANNEL(Y, 1), | |
259 | MAG3110_CHANNEL(Z, 2), | |
260 | { | |
261 | .type = IIO_TEMP, | |
262 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), | |
263 | .scan_index = 3, | |
264 | .scan_type = IIO_ST('s', 8, 8, 0), | |
265 | }, | |
266 | IIO_CHAN_SOFT_TIMESTAMP(4), | |
267 | }; | |
268 | ||
269 | static struct attribute *mag3110_attributes[] = { | |
270 | &iio_dev_attr_sampling_frequency_available.dev_attr.attr, | |
271 | NULL | |
272 | }; | |
273 | ||
274 | static const struct attribute_group mag3110_group = { | |
275 | .attrs = mag3110_attributes, | |
276 | }; | |
277 | ||
278 | static const struct iio_info mag3110_info = { | |
279 | .attrs = &mag3110_group, | |
280 | .read_raw = &mag3110_read_raw, | |
281 | .write_raw = &mag3110_write_raw, | |
282 | .driver_module = THIS_MODULE, | |
283 | }; | |
284 | ||
285 | static const unsigned long mag3110_scan_masks[] = {0x7, 0xf, 0}; | |
286 | ||
287 | static int mag3110_probe(struct i2c_client *client, | |
288 | const struct i2c_device_id *id) | |
289 | { | |
290 | struct mag3110_data *data; | |
291 | struct iio_dev *indio_dev; | |
292 | int ret; | |
293 | ||
294 | ret = i2c_smbus_read_byte_data(client, MAG3110_WHO_AM_I); | |
295 | if (ret < 0) | |
296 | return ret; | |
297 | if (ret != MAG3110_DEVICE_ID) | |
298 | return -ENODEV; | |
299 | ||
300 | indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); | |
301 | if (!indio_dev) | |
302 | return -ENOMEM; | |
303 | ||
304 | data = iio_priv(indio_dev); | |
305 | data->client = client; | |
306 | mutex_init(&data->lock); | |
307 | ||
308 | i2c_set_clientdata(client, indio_dev); | |
309 | indio_dev->info = &mag3110_info; | |
310 | indio_dev->name = id->name; | |
311 | indio_dev->dev.parent = &client->dev; | |
312 | indio_dev->modes = INDIO_DIRECT_MODE; | |
313 | indio_dev->channels = mag3110_channels; | |
314 | indio_dev->num_channels = ARRAY_SIZE(mag3110_channels); | |
315 | indio_dev->available_scan_masks = mag3110_scan_masks; | |
316 | ||
317 | data->ctrl_reg1 = MAG3110_CTRL_DR_DEFAULT; | |
318 | ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG1, | |
319 | data->ctrl_reg1); | |
320 | if (ret < 0) | |
321 | return ret; | |
322 | ||
323 | ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG2, | |
324 | MAG3110_CTRL_AUTO_MRST_EN | MAG3110_CTRL_RAW); | |
325 | if (ret < 0) | |
326 | return ret; | |
327 | ||
328 | ret = iio_triggered_buffer_setup(indio_dev, NULL, | |
329 | mag3110_trigger_handler, NULL); | |
330 | if (ret < 0) | |
331 | return ret; | |
332 | ||
333 | ret = iio_device_register(indio_dev); | |
334 | if (ret < 0) | |
335 | goto buffer_cleanup; | |
336 | return 0; | |
337 | ||
338 | buffer_cleanup: | |
339 | iio_triggered_buffer_cleanup(indio_dev); | |
340 | return ret; | |
341 | } | |
342 | ||
343 | static int mag3110_standby(struct mag3110_data *data) | |
344 | { | |
345 | return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1, | |
346 | data->ctrl_reg1 & ~MAG3110_CTRL_AC); | |
347 | } | |
348 | ||
349 | static int mag3110_remove(struct i2c_client *client) | |
350 | { | |
351 | struct iio_dev *indio_dev = i2c_get_clientdata(client); | |
352 | ||
353 | iio_device_unregister(indio_dev); | |
354 | iio_triggered_buffer_cleanup(indio_dev); | |
355 | mag3110_standby(iio_priv(indio_dev)); | |
356 | ||
357 | return 0; | |
358 | } | |
359 | ||
360 | #ifdef CONFIG_PM_SLEEP | |
361 | static int mag3110_suspend(struct device *dev) | |
362 | { | |
363 | return mag3110_standby(iio_priv(i2c_get_clientdata( | |
364 | to_i2c_client(dev)))); | |
365 | } | |
366 | ||
367 | static int mag3110_resume(struct device *dev) | |
368 | { | |
369 | struct mag3110_data *data = iio_priv(i2c_get_clientdata( | |
370 | to_i2c_client(dev))); | |
371 | ||
372 | return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1, | |
373 | data->ctrl_reg1); | |
374 | } | |
375 | ||
376 | static SIMPLE_DEV_PM_OPS(mag3110_pm_ops, mag3110_suspend, mag3110_resume); | |
377 | #define MAG3110_PM_OPS (&mag3110_pm_ops) | |
378 | #else | |
379 | #define MAG3110_PM_OPS NULL | |
380 | #endif | |
381 | ||
382 | static const struct i2c_device_id mag3110_id[] = { | |
383 | { "mag3110", 0 }, | |
384 | { } | |
385 | }; | |
386 | MODULE_DEVICE_TABLE(i2c, mag3110_id); | |
387 | ||
388 | static struct i2c_driver mag3110_driver = { | |
389 | .driver = { | |
390 | .name = "mag3110", | |
391 | .pm = MAG3110_PM_OPS, | |
392 | }, | |
393 | .probe = mag3110_probe, | |
394 | .remove = mag3110_remove, | |
395 | .id_table = mag3110_id, | |
396 | }; | |
397 | module_i2c_driver(mag3110_driver); | |
398 | ||
399 | MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>"); | |
400 | MODULE_DESCRIPTION("Freescale MAG3110 magnetometer driver"); | |
401 | MODULE_LICENSE("GPL"); |