1 // SPDX-License-Identifier: GPL-2.0-only
3 * mag3110.c - Support for Freescale MAG3110 magnetometer sensor
5 * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
7 * (7-bit I2C slave address 0x0e)
9 * TODO: irq, user offset, oversampling, continuous mode
12 #include <linux/module.h>
13 #include <linux/i2c.h>
14 #include <linux/iio/iio.h>
15 #include <linux/iio/sysfs.h>
16 #include <linux/iio/trigger_consumer.h>
17 #include <linux/iio/buffer.h>
18 #include <linux/iio/triggered_buffer.h>
19 #include <linux/delay.h>
20 #include <linux/regulator/consumer.h>
22 #define MAG3110_STATUS 0x00
23 #define MAG3110_OUT_X 0x01 /* MSB first */
24 #define MAG3110_OUT_Y 0x03
25 #define MAG3110_OUT_Z 0x05
26 #define MAG3110_WHO_AM_I 0x07
27 #define MAG3110_SYSMOD 0x08
28 #define MAG3110_OFF_X 0x09 /* MSB first */
29 #define MAG3110_OFF_Y 0x0b
30 #define MAG3110_OFF_Z 0x0d
31 #define MAG3110_DIE_TEMP 0x0f
32 #define MAG3110_CTRL_REG1 0x10
33 #define MAG3110_CTRL_REG2 0x11
35 #define MAG3110_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0))
37 #define MAG3110_CTRL_DR_MASK (BIT(7) | BIT(6) | BIT(5))
38 #define MAG3110_CTRL_DR_SHIFT 5
39 #define MAG3110_CTRL_DR_DEFAULT 0
41 #define MAG3110_SYSMOD_MODE_MASK GENMASK(1, 0)
43 #define MAG3110_CTRL_TM BIT(1) /* trigger single measurement */
44 #define MAG3110_CTRL_AC BIT(0) /* continuous measurements */
46 #define MAG3110_CTRL_AUTO_MRST_EN BIT(7) /* magnetic auto-reset */
47 #define MAG3110_CTRL_RAW BIT(5) /* measurements not user-offset corrected */
49 #define MAG3110_DEVICE_ID 0xc4
51 /* Each client has this additional data */
53 struct i2c_client *client;
57 struct regulator *vdd_reg;
58 struct regulator *vddio_reg;
59 /* Ensure natural alignment of timestamp */
67 static int mag3110_request(struct mag3110_data *data)
71 if ((data->ctrl_reg1 & MAG3110_CTRL_AC) == 0) {
72 /* trigger measurement */
73 ret = i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
74 data->ctrl_reg1 | MAG3110_CTRL_TM);
80 ret = i2c_smbus_read_byte_data(data->client, MAG3110_STATUS);
83 /* wait for data ready */
84 if ((ret & MAG3110_STATUS_DRDY) == MAG3110_STATUS_DRDY)
87 if (data->sleep_val <= 20)
88 usleep_range(data->sleep_val * 250, data->sleep_val * 500);
94 dev_err(&data->client->dev, "data not ready\n");
101 static int mag3110_read(struct mag3110_data *data, __be16 buf[3])
105 mutex_lock(&data->lock);
106 ret = mag3110_request(data);
108 mutex_unlock(&data->lock);
111 ret = i2c_smbus_read_i2c_block_data(data->client,
112 MAG3110_OUT_X, 3 * sizeof(__be16), (u8 *) buf);
113 mutex_unlock(&data->lock);
118 static ssize_t mag3110_show_int_plus_micros(char *buf,
119 const int (*vals)[2], int n)
124 len += scnprintf(buf + len, PAGE_SIZE - len,
125 "%d.%06d ", vals[n][0], vals[n][1]);
127 /* replace trailing space by newline */
133 static int mag3110_get_int_plus_micros_index(const int (*vals)[2], int n,
137 if (val == vals[n][0] && val2 == vals[n][1])
143 static const int mag3110_samp_freq[8][2] = {
144 {80, 0}, {40, 0}, {20, 0}, {10, 0}, {5, 0}, {2, 500000},
145 {1, 250000}, {0, 625000}
148 static ssize_t mag3110_show_samp_freq_avail(struct device *dev,
149 struct device_attribute *attr, char *buf)
151 return mag3110_show_int_plus_micros(buf, mag3110_samp_freq, 8);
154 static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(mag3110_show_samp_freq_avail);
156 static int mag3110_get_samp_freq_index(struct mag3110_data *data,
159 return mag3110_get_int_plus_micros_index(mag3110_samp_freq, 8, val,
163 static int mag3110_calculate_sleep(struct mag3110_data *data)
165 int ret, i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT;
167 if (mag3110_samp_freq[i][0] > 0)
168 ret = 1000 / mag3110_samp_freq[i][0];
172 return ret == 0 ? 1 : ret;
175 static int mag3110_standby(struct mag3110_data *data)
177 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
178 data->ctrl_reg1 & ~MAG3110_CTRL_AC);
181 static int mag3110_wait_standby(struct mag3110_data *data)
186 * Takes up to 1/ODR to come out of active mode into stby
187 * Longest expected period is 12.5seconds.
188 * We'll sleep for 500ms between checks
190 while (tries-- > 0) {
191 ret = i2c_smbus_read_byte_data(data->client, MAG3110_SYSMOD);
193 dev_err(&data->client->dev, "i2c error\n");
196 /* wait for standby */
197 if ((ret & MAG3110_SYSMOD_MODE_MASK) == 0)
200 msleep_interruptible(500);
204 dev_err(&data->client->dev, "device not entering standby mode\n");
211 static int mag3110_active(struct mag3110_data *data)
213 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
217 /* returns >0 if active, 0 if in standby and <0 on error */
218 static int mag3110_is_active(struct mag3110_data *data)
222 reg = i2c_smbus_read_byte_data(data->client, MAG3110_CTRL_REG1);
226 return reg & MAG3110_CTRL_AC;
229 static int mag3110_change_config(struct mag3110_data *data, u8 reg, u8 val)
234 mutex_lock(&data->lock);
236 is_active = mag3110_is_active(data);
242 /* config can only be changed when in standby */
244 ret = mag3110_standby(data);
250 * After coming out of active we must wait for the part
251 * to transition to STBY. This can take up to 1 /ODR to occur
253 ret = mag3110_wait_standby(data);
257 ret = i2c_smbus_write_byte_data(data->client, reg, val);
262 ret = mag3110_active(data);
269 mutex_unlock(&data->lock);
274 static int mag3110_read_raw(struct iio_dev *indio_dev,
275 struct iio_chan_spec const *chan,
276 int *val, int *val2, long mask)
278 struct mag3110_data *data = iio_priv(indio_dev);
283 case IIO_CHAN_INFO_RAW:
284 ret = iio_device_claim_direct_mode(indio_dev);
288 switch (chan->type) {
289 case IIO_MAGN: /* in 0.1 uT / LSB */
290 ret = mag3110_read(data, buffer);
293 *val = sign_extend32(
294 be16_to_cpu(buffer[chan->scan_index]), 15);
297 case IIO_TEMP: /* in 1 C / LSB */
298 mutex_lock(&data->lock);
299 ret = mag3110_request(data);
301 mutex_unlock(&data->lock);
304 ret = i2c_smbus_read_byte_data(data->client,
306 mutex_unlock(&data->lock);
309 *val = sign_extend32(ret, 7);
316 iio_device_release_direct_mode(indio_dev);
319 case IIO_CHAN_INFO_SCALE:
320 switch (chan->type) {
324 return IIO_VAL_INT_PLUS_MICRO;
331 case IIO_CHAN_INFO_SAMP_FREQ:
332 i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT;
333 *val = mag3110_samp_freq[i][0];
334 *val2 = mag3110_samp_freq[i][1];
335 return IIO_VAL_INT_PLUS_MICRO;
336 case IIO_CHAN_INFO_CALIBBIAS:
337 ret = i2c_smbus_read_word_swapped(data->client,
338 MAG3110_OFF_X + 2 * chan->scan_index);
341 *val = sign_extend32(ret >> 1, 14);
347 static int mag3110_write_raw(struct iio_dev *indio_dev,
348 struct iio_chan_spec const *chan,
349 int val, int val2, long mask)
351 struct mag3110_data *data = iio_priv(indio_dev);
354 ret = iio_device_claim_direct_mode(indio_dev);
359 case IIO_CHAN_INFO_SAMP_FREQ:
360 rate = mag3110_get_samp_freq_index(data, val, val2);
365 data->ctrl_reg1 &= 0xff & ~MAG3110_CTRL_DR_MASK
367 data->ctrl_reg1 |= rate << MAG3110_CTRL_DR_SHIFT;
368 data->sleep_val = mag3110_calculate_sleep(data);
369 if (data->sleep_val < 40)
370 data->ctrl_reg1 |= MAG3110_CTRL_AC;
372 ret = mag3110_change_config(data, MAG3110_CTRL_REG1,
375 case IIO_CHAN_INFO_CALIBBIAS:
376 if (val < -10000 || val > 10000) {
380 ret = i2c_smbus_write_word_swapped(data->client,
381 MAG3110_OFF_X + 2 * chan->scan_index, val << 1);
387 iio_device_release_direct_mode(indio_dev);
391 static irqreturn_t mag3110_trigger_handler(int irq, void *p)
393 struct iio_poll_func *pf = p;
394 struct iio_dev *indio_dev = pf->indio_dev;
395 struct mag3110_data *data = iio_priv(indio_dev);
398 ret = mag3110_read(data, data->scan.channels);
402 if (test_bit(3, indio_dev->active_scan_mask)) {
403 ret = i2c_smbus_read_byte_data(data->client,
407 data->scan.temperature = ret;
410 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
411 iio_get_time_ns(indio_dev));
414 iio_trigger_notify_done(indio_dev->trig);
418 #define MAG3110_CHANNEL(axis, idx) { \
421 .channel2 = IIO_MOD_##axis, \
422 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
423 BIT(IIO_CHAN_INFO_CALIBBIAS), \
424 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
425 BIT(IIO_CHAN_INFO_SCALE), \
431 .endianness = IIO_BE, \
435 static const struct iio_chan_spec mag3110_channels[] = {
436 MAG3110_CHANNEL(X, 0),
437 MAG3110_CHANNEL(Y, 1),
438 MAG3110_CHANNEL(Z, 2),
441 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
442 BIT(IIO_CHAN_INFO_SCALE),
450 IIO_CHAN_SOFT_TIMESTAMP(4),
453 static struct attribute *mag3110_attributes[] = {
454 &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
458 static const struct attribute_group mag3110_group = {
459 .attrs = mag3110_attributes,
462 static const struct iio_info mag3110_info = {
463 .attrs = &mag3110_group,
464 .read_raw = &mag3110_read_raw,
465 .write_raw = &mag3110_write_raw,
468 static const unsigned long mag3110_scan_masks[] = {0x7, 0xf, 0};
470 static int mag3110_probe(struct i2c_client *client,
471 const struct i2c_device_id *id)
473 struct mag3110_data *data;
474 struct iio_dev *indio_dev;
477 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
481 data = iio_priv(indio_dev);
483 data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
484 if (IS_ERR(data->vdd_reg))
485 return dev_err_probe(&client->dev, PTR_ERR(data->vdd_reg),
486 "failed to get VDD regulator!\n");
488 data->vddio_reg = devm_regulator_get(&client->dev, "vddio");
489 if (IS_ERR(data->vddio_reg))
490 return dev_err_probe(&client->dev, PTR_ERR(data->vddio_reg),
491 "failed to get VDDIO regulator!\n");
493 ret = regulator_enable(data->vdd_reg);
495 dev_err(&client->dev, "failed to enable VDD regulator!\n");
499 ret = regulator_enable(data->vddio_reg);
501 dev_err(&client->dev, "failed to enable VDDIO regulator!\n");
502 goto disable_regulator_vdd;
505 ret = i2c_smbus_read_byte_data(client, MAG3110_WHO_AM_I);
507 goto disable_regulators;
508 if (ret != MAG3110_DEVICE_ID) {
510 goto disable_regulators;
513 data->client = client;
514 mutex_init(&data->lock);
516 i2c_set_clientdata(client, indio_dev);
517 indio_dev->info = &mag3110_info;
518 indio_dev->name = id->name;
519 indio_dev->modes = INDIO_DIRECT_MODE;
520 indio_dev->channels = mag3110_channels;
521 indio_dev->num_channels = ARRAY_SIZE(mag3110_channels);
522 indio_dev->available_scan_masks = mag3110_scan_masks;
524 data->ctrl_reg1 = MAG3110_CTRL_DR_DEFAULT << MAG3110_CTRL_DR_SHIFT;
525 data->sleep_val = mag3110_calculate_sleep(data);
526 if (data->sleep_val < 40)
527 data->ctrl_reg1 |= MAG3110_CTRL_AC;
529 ret = mag3110_change_config(data, MAG3110_CTRL_REG1, data->ctrl_reg1);
531 goto disable_regulators;
533 ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG2,
534 MAG3110_CTRL_AUTO_MRST_EN);
536 goto standby_on_error;
538 ret = iio_triggered_buffer_setup(indio_dev, NULL,
539 mag3110_trigger_handler, NULL);
541 goto standby_on_error;
543 ret = iio_device_register(indio_dev);
549 iio_triggered_buffer_cleanup(indio_dev);
551 mag3110_standby(iio_priv(indio_dev));
553 regulator_disable(data->vddio_reg);
554 disable_regulator_vdd:
555 regulator_disable(data->vdd_reg);
560 static int mag3110_remove(struct i2c_client *client)
562 struct iio_dev *indio_dev = i2c_get_clientdata(client);
563 struct mag3110_data *data = iio_priv(indio_dev);
565 iio_device_unregister(indio_dev);
566 iio_triggered_buffer_cleanup(indio_dev);
567 mag3110_standby(iio_priv(indio_dev));
568 regulator_disable(data->vddio_reg);
569 regulator_disable(data->vdd_reg);
574 #ifdef CONFIG_PM_SLEEP
575 static int mag3110_suspend(struct device *dev)
577 struct mag3110_data *data = iio_priv(i2c_get_clientdata(
578 to_i2c_client(dev)));
581 ret = mag3110_standby(iio_priv(i2c_get_clientdata(
582 to_i2c_client(dev))));
586 ret = regulator_disable(data->vddio_reg);
588 dev_err(dev, "failed to disable VDDIO regulator\n");
592 ret = regulator_disable(data->vdd_reg);
594 dev_err(dev, "failed to disable VDD regulator\n");
601 static int mag3110_resume(struct device *dev)
603 struct mag3110_data *data = iio_priv(i2c_get_clientdata(
604 to_i2c_client(dev)));
607 ret = regulator_enable(data->vdd_reg);
609 dev_err(dev, "failed to enable VDD regulator\n");
613 ret = regulator_enable(data->vddio_reg);
615 dev_err(dev, "failed to enable VDDIO regulator\n");
616 regulator_disable(data->vdd_reg);
620 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
624 static SIMPLE_DEV_PM_OPS(mag3110_pm_ops, mag3110_suspend, mag3110_resume);
625 #define MAG3110_PM_OPS (&mag3110_pm_ops)
627 #define MAG3110_PM_OPS NULL
630 static const struct i2c_device_id mag3110_id[] = {
634 MODULE_DEVICE_TABLE(i2c, mag3110_id);
636 static const struct of_device_id mag3110_of_match[] = {
637 { .compatible = "fsl,mag3110" },
640 MODULE_DEVICE_TABLE(of, mag3110_of_match);
642 static struct i2c_driver mag3110_driver = {
645 .of_match_table = mag3110_of_match,
646 .pm = MAG3110_PM_OPS,
648 .probe = mag3110_probe,
649 .remove = mag3110_remove,
650 .id_table = mag3110_id,
652 module_i2c_driver(mag3110_driver);
654 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
655 MODULE_DESCRIPTION("Freescale MAG3110 magnetometer driver");
656 MODULE_LICENSE("GPL");