2 * mag3110.c - Support for Freescale MAG3110 magnetometer sensor
4 * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
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.
10 * (7-bit I2C slave address 0x0e)
12 * TODO: irq, user offset, oversampling, continuous mode
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>
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
36 #define MAG3110_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0))
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
42 #define MAG3110_CTRL_TM BIT(1) /* trigger single measurement */
43 #define MAG3110_CTRL_AC BIT(0) /* continuous measurements */
45 #define MAG3110_CTRL_AUTO_MRST_EN BIT(7) /* magnetic auto-reset */
46 #define MAG3110_CTRL_RAW BIT(5) /* measurements not user-offset corrected */
48 #define MAG3110_DEVICE_ID 0xc4
50 /* Each client has this additional data */
52 struct i2c_client *client;
55 /* Ensure natural alignment of timestamp */
63 static int mag3110_request(struct mag3110_data *data)
67 /* trigger measurement */
68 ret = i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
69 data->ctrl_reg1 | MAG3110_CTRL_TM);
74 ret = i2c_smbus_read_byte_data(data->client, MAG3110_STATUS);
77 /* wait for data ready */
78 if ((ret & MAG3110_STATUS_DRDY) == MAG3110_STATUS_DRDY)
84 dev_err(&data->client->dev, "data not ready\n");
91 static int mag3110_read(struct mag3110_data *data, __be16 buf[3])
95 mutex_lock(&data->lock);
96 ret = mag3110_request(data);
98 mutex_unlock(&data->lock);
101 ret = i2c_smbus_read_i2c_block_data(data->client,
102 MAG3110_OUT_X, 3 * sizeof(__be16), (u8 *) buf);
103 mutex_unlock(&data->lock);
108 static ssize_t mag3110_show_int_plus_micros(char *buf,
109 const int (*vals)[2], int n)
114 len += scnprintf(buf + len, PAGE_SIZE - len,
115 "%d.%06d ", vals[n][0], vals[n][1]);
117 /* replace trailing space by newline */
123 static int mag3110_get_int_plus_micros_index(const int (*vals)[2], int n,
127 if (val == vals[n][0] && val2 == vals[n][1])
133 static const int mag3110_samp_freq[8][2] = {
134 {80, 0}, {40, 0}, {20, 0}, {10, 0}, {5, 0}, {2, 500000},
135 {1, 250000}, {0, 625000}
138 static ssize_t mag3110_show_samp_freq_avail(struct device *dev,
139 struct device_attribute *attr, char *buf)
141 return mag3110_show_int_plus_micros(buf, mag3110_samp_freq, 8);
144 static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(mag3110_show_samp_freq_avail);
146 static int mag3110_get_samp_freq_index(struct mag3110_data *data,
149 return mag3110_get_int_plus_micros_index(mag3110_samp_freq, 8, val,
153 static int mag3110_read_raw(struct iio_dev *indio_dev,
154 struct iio_chan_spec const *chan,
155 int *val, int *val2, long mask)
157 struct mag3110_data *data = iio_priv(indio_dev);
162 case IIO_CHAN_INFO_RAW:
163 ret = iio_device_claim_direct_mode(indio_dev);
167 switch (chan->type) {
168 case IIO_MAGN: /* in 0.1 uT / LSB */
169 ret = mag3110_read(data, buffer);
172 *val = sign_extend32(
173 be16_to_cpu(buffer[chan->scan_index]), 15);
176 case IIO_TEMP: /* in 1 C / LSB */
177 mutex_lock(&data->lock);
178 ret = mag3110_request(data);
180 mutex_unlock(&data->lock);
183 ret = i2c_smbus_read_byte_data(data->client,
185 mutex_unlock(&data->lock);
188 *val = sign_extend32(ret, 7);
195 iio_device_release_direct_mode(indio_dev);
198 case IIO_CHAN_INFO_SCALE:
199 switch (chan->type) {
203 return IIO_VAL_INT_PLUS_MICRO;
210 case IIO_CHAN_INFO_SAMP_FREQ:
211 i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT;
212 *val = mag3110_samp_freq[i][0];
213 *val2 = mag3110_samp_freq[i][1];
214 return IIO_VAL_INT_PLUS_MICRO;
215 case IIO_CHAN_INFO_CALIBBIAS:
216 ret = i2c_smbus_read_word_swapped(data->client,
217 MAG3110_OFF_X + 2 * chan->scan_index);
220 *val = sign_extend32(ret >> 1, 14);
226 static int mag3110_write_raw(struct iio_dev *indio_dev,
227 struct iio_chan_spec const *chan,
228 int val, int val2, long mask)
230 struct mag3110_data *data = iio_priv(indio_dev);
233 ret = iio_device_claim_direct_mode(indio_dev);
238 case IIO_CHAN_INFO_SAMP_FREQ:
239 rate = mag3110_get_samp_freq_index(data, val, val2);
245 data->ctrl_reg1 &= ~MAG3110_CTRL_DR_MASK;
246 data->ctrl_reg1 |= rate << MAG3110_CTRL_DR_SHIFT;
247 ret = i2c_smbus_write_byte_data(data->client,
248 MAG3110_CTRL_REG1, data->ctrl_reg1);
250 case IIO_CHAN_INFO_CALIBBIAS:
251 if (val < -10000 || val > 10000) {
255 ret = i2c_smbus_write_word_swapped(data->client,
256 MAG3110_OFF_X + 2 * chan->scan_index, val << 1);
262 iio_device_release_direct_mode(indio_dev);
266 static irqreturn_t mag3110_trigger_handler(int irq, void *p)
268 struct iio_poll_func *pf = p;
269 struct iio_dev *indio_dev = pf->indio_dev;
270 struct mag3110_data *data = iio_priv(indio_dev);
273 ret = mag3110_read(data, data->scan.channels);
277 if (test_bit(3, indio_dev->active_scan_mask)) {
278 ret = i2c_smbus_read_byte_data(data->client,
282 data->scan.temperature = ret;
285 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
286 iio_get_time_ns(indio_dev));
289 iio_trigger_notify_done(indio_dev->trig);
293 #define MAG3110_CHANNEL(axis, idx) { \
296 .channel2 = IIO_MOD_##axis, \
297 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
298 BIT(IIO_CHAN_INFO_CALIBBIAS), \
299 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
300 BIT(IIO_CHAN_INFO_SCALE), \
306 .endianness = IIO_BE, \
310 static const struct iio_chan_spec mag3110_channels[] = {
311 MAG3110_CHANNEL(X, 0),
312 MAG3110_CHANNEL(Y, 1),
313 MAG3110_CHANNEL(Z, 2),
316 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
317 BIT(IIO_CHAN_INFO_SCALE),
325 IIO_CHAN_SOFT_TIMESTAMP(4),
328 static struct attribute *mag3110_attributes[] = {
329 &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
333 static const struct attribute_group mag3110_group = {
334 .attrs = mag3110_attributes,
337 static const struct iio_info mag3110_info = {
338 .attrs = &mag3110_group,
339 .read_raw = &mag3110_read_raw,
340 .write_raw = &mag3110_write_raw,
341 .driver_module = THIS_MODULE,
344 static const unsigned long mag3110_scan_masks[] = {0x7, 0xf, 0};
346 static int mag3110_standby(struct mag3110_data *data)
348 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
349 data->ctrl_reg1 & ~MAG3110_CTRL_AC);
352 static int mag3110_probe(struct i2c_client *client,
353 const struct i2c_device_id *id)
355 struct mag3110_data *data;
356 struct iio_dev *indio_dev;
359 ret = i2c_smbus_read_byte_data(client, MAG3110_WHO_AM_I);
362 if (ret != MAG3110_DEVICE_ID)
365 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
369 data = iio_priv(indio_dev);
370 data->client = client;
371 mutex_init(&data->lock);
373 i2c_set_clientdata(client, indio_dev);
374 indio_dev->info = &mag3110_info;
375 indio_dev->name = id->name;
376 indio_dev->dev.parent = &client->dev;
377 indio_dev->modes = INDIO_DIRECT_MODE;
378 indio_dev->channels = mag3110_channels;
379 indio_dev->num_channels = ARRAY_SIZE(mag3110_channels);
380 indio_dev->available_scan_masks = mag3110_scan_masks;
382 data->ctrl_reg1 = MAG3110_CTRL_DR_DEFAULT << MAG3110_CTRL_DR_SHIFT;
383 ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG1,
388 ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG2,
389 MAG3110_CTRL_AUTO_MRST_EN);
391 goto standby_on_error;
393 ret = iio_triggered_buffer_setup(indio_dev, NULL,
394 mag3110_trigger_handler, NULL);
396 goto standby_on_error;
398 ret = iio_device_register(indio_dev);
404 iio_triggered_buffer_cleanup(indio_dev);
406 mag3110_standby(iio_priv(indio_dev));
410 static int mag3110_remove(struct i2c_client *client)
412 struct iio_dev *indio_dev = i2c_get_clientdata(client);
414 iio_device_unregister(indio_dev);
415 iio_triggered_buffer_cleanup(indio_dev);
416 mag3110_standby(iio_priv(indio_dev));
421 #ifdef CONFIG_PM_SLEEP
422 static int mag3110_suspend(struct device *dev)
424 return mag3110_standby(iio_priv(i2c_get_clientdata(
425 to_i2c_client(dev))));
428 static int mag3110_resume(struct device *dev)
430 struct mag3110_data *data = iio_priv(i2c_get_clientdata(
431 to_i2c_client(dev)));
433 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
437 static SIMPLE_DEV_PM_OPS(mag3110_pm_ops, mag3110_suspend, mag3110_resume);
438 #define MAG3110_PM_OPS (&mag3110_pm_ops)
440 #define MAG3110_PM_OPS NULL
443 static const struct i2c_device_id mag3110_id[] = {
447 MODULE_DEVICE_TABLE(i2c, mag3110_id);
449 static const struct of_device_id mag3110_of_match[] = {
450 { .compatible = "fsl,mag3110" },
453 MODULE_DEVICE_TABLE(of, mag3110_of_match);
455 static struct i2c_driver mag3110_driver = {
458 .of_match_table = mag3110_of_match,
459 .pm = MAG3110_PM_OPS,
461 .probe = mag3110_probe,
462 .remove = mag3110_remove,
463 .id_table = mag3110_id,
465 module_i2c_driver(mag3110_driver);
467 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
468 MODULE_DESCRIPTION("Freescale MAG3110 magnetometer driver");
469 MODULE_LICENSE("GPL");