2 * Device driver for the the HMC5843 multi-chip module designed
3 * for low field magnetic sensing.
5 * Copyright (C) 2010 Texas Instruments
7 * Author: Shubhrajyoti Datta <shubhrajyoti@ti.com>
8 * Acknowledgment: Jonathan Cameron <jic23@kernel.org> for valuable inputs.
9 * Support for HMC5883 and HMC5883L by Peter Meerwald <pmeerw@pmeerw.net>.
10 * Split to multiple files by Josef Gajdusek <atx@atx.name> - 2014
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
24 #include <linux/module.h>
25 #include <linux/regmap.h>
26 #include <linux/iio/iio.h>
27 #include <linux/iio/sysfs.h>
28 #include <linux/iio/trigger_consumer.h>
29 #include <linux/iio/buffer.h>
30 #include <linux/iio/triggered_buffer.h>
31 #include <linux/delay.h>
36 * Range gain settings in (+-)Ga
37 * Beware: HMC5843 and HMC5883 have different recommended sensor field
38 * ranges; default corresponds to +-1.0 Ga and +-1.3 Ga, respectively
40 #define HMC5843_RANGE_GAIN_OFFSET 0x05
41 #define HMC5843_RANGE_GAIN_DEFAULT 0x01
42 #define HMC5843_RANGE_GAIN_MASK 0xe0
45 #define HMC5843_DATA_READY 0x01
46 #define HMC5843_DATA_OUTPUT_LOCK 0x02
48 /* Mode register configuration */
49 #define HMC5843_MODE_CONVERSION_CONTINUOUS 0x00
50 #define HMC5843_MODE_CONVERSION_SINGLE 0x01
51 #define HMC5843_MODE_IDLE 0x02
52 #define HMC5843_MODE_SLEEP 0x03
53 #define HMC5843_MODE_MASK 0x03
56 * HMC5843: Minimum data output rate
57 * HMC5883: Typical data output rate
59 #define HMC5843_RATE_OFFSET 0x02
60 #define HMC5843_RATE_DEFAULT 0x04
61 #define HMC5843_RATE_MASK 0x1c
63 /* Device measurement configuration */
64 #define HMC5843_MEAS_CONF_NORMAL 0x00
65 #define HMC5843_MEAS_CONF_POSITIVE_BIAS 0x01
66 #define HMC5843_MEAS_CONF_NEGATIVE_BIAS 0x02
67 #define HMC5843_MEAS_CONF_MASK 0x03
69 /* Scaling factors: 10000000/Gain */
70 static const int hmc5843_regval_to_nanoscale[] = {
71 6173, 7692, 10309, 12821, 18868, 21739, 25641, 35714
74 static const int hmc5883_regval_to_nanoscale[] = {
75 7812, 9766, 13021, 16287, 24096, 27701, 32573, 45662
78 static const int hmc5883l_regval_to_nanoscale[] = {
79 7299, 9174, 12195, 15152, 22727, 25641, 30303, 43478
84 * Value | HMC5843 | HMC5883/HMC5883L
85 * | Data output rate (Hz) | Data output rate (Hz)
90 * 4 | 10 (default) | 15
93 * 7 | Not used | Not used
95 static const int hmc5843_regval_to_samp_freq[][2] = {
96 {0, 500000}, {1, 0}, {2, 0}, {5, 0}, {10, 0}, {20, 0}, {50, 0}
99 static const int hmc5883_regval_to_samp_freq[][2] = {
100 {0, 750000}, {1, 500000}, {3, 0}, {7, 500000}, {15, 0}, {30, 0},
104 static const int hmc5983_regval_to_samp_freq[][2] = {
105 {0, 750000}, {1, 500000}, {3, 0}, {7, 500000}, {15, 0}, {30, 0},
109 /* Describe chip variants */
110 struct hmc5843_chip_info {
111 const struct iio_chan_spec *channels;
112 const int (*regval_to_samp_freq)[2];
113 const int n_regval_to_samp_freq;
114 const int *regval_to_nanoscale;
115 const int n_regval_to_nanoscale;
118 /* The lower two bits contain the current conversion mode */
119 static s32 hmc5843_set_mode(struct hmc5843_data *data, u8 operating_mode)
123 mutex_lock(&data->lock);
124 ret = regmap_update_bits(data->regmap, HMC5843_MODE_REG,
125 HMC5843_MODE_MASK, operating_mode);
126 mutex_unlock(&data->lock);
131 static int hmc5843_wait_measurement(struct hmc5843_data *data)
137 while (tries-- > 0) {
138 ret = regmap_read(data->regmap, HMC5843_STATUS_REG, &val);
141 if (val & HMC5843_DATA_READY)
147 dev_err(data->dev, "data not ready\n");
154 /* Return the measurement value from the specified channel */
155 static int hmc5843_read_measurement(struct hmc5843_data *data,
161 mutex_lock(&data->lock);
162 ret = hmc5843_wait_measurement(data);
164 mutex_unlock(&data->lock);
167 ret = regmap_bulk_read(data->regmap, HMC5843_DATA_OUT_MSB_REGS,
168 values, sizeof(values));
169 mutex_unlock(&data->lock);
173 *val = sign_extend32(be16_to_cpu(values[idx]), 15);
178 * API for setting the measurement configuration to
179 * Normal, Positive bias and Negative bias
181 * From the datasheet:
182 * 0 - Normal measurement configuration (default): In normal measurement
183 * configuration the device follows normal measurement flow. Pins BP
184 * and BN are left floating and high impedance.
186 * 1 - Positive bias configuration: In positive bias configuration, a
187 * positive current is forced across the resistive load on pins BP
190 * 2 - Negative bias configuration. In negative bias configuration, a
191 * negative current is forced across the resistive load on pins BP
195 static int hmc5843_set_meas_conf(struct hmc5843_data *data, u8 meas_conf)
199 mutex_lock(&data->lock);
200 ret = regmap_update_bits(data->regmap, HMC5843_CONFIG_REG_A,
201 HMC5843_MEAS_CONF_MASK, meas_conf);
202 mutex_unlock(&data->lock);
208 ssize_t hmc5843_show_measurement_configuration(struct device *dev,
209 struct device_attribute *attr,
212 struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev));
216 ret = regmap_read(data->regmap, HMC5843_CONFIG_REG_A, &val);
219 val &= HMC5843_MEAS_CONF_MASK;
221 return sprintf(buf, "%d\n", val);
225 ssize_t hmc5843_set_measurement_configuration(struct device *dev,
226 struct device_attribute *attr,
230 struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev));
231 unsigned long meas_conf = 0;
234 ret = kstrtoul(buf, 10, &meas_conf);
237 if (meas_conf >= HMC5843_MEAS_CONF_MASK)
240 ret = hmc5843_set_meas_conf(data, meas_conf);
242 return (ret < 0) ? ret : count;
245 static IIO_DEVICE_ATTR(meas_conf,
247 hmc5843_show_measurement_configuration,
248 hmc5843_set_measurement_configuration,
252 ssize_t hmc5843_show_samp_freq_avail(struct device *dev,
253 struct device_attribute *attr, char *buf)
255 struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev));
259 for (i = 0; i < data->variant->n_regval_to_samp_freq; i++)
260 len += scnprintf(buf + len, PAGE_SIZE - len,
261 "%d.%d ", data->variant->regval_to_samp_freq[i][0],
262 data->variant->regval_to_samp_freq[i][1]);
264 /* replace trailing space by newline */
270 static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(hmc5843_show_samp_freq_avail);
272 static int hmc5843_set_samp_freq(struct hmc5843_data *data, u8 rate)
276 mutex_lock(&data->lock);
277 ret = regmap_update_bits(data->regmap, HMC5843_CONFIG_REG_A,
279 rate << HMC5843_RATE_OFFSET);
280 mutex_unlock(&data->lock);
285 static int hmc5843_get_samp_freq_index(struct hmc5843_data *data,
290 for (i = 0; i < data->variant->n_regval_to_samp_freq; i++)
291 if (val == data->variant->regval_to_samp_freq[i][0] &&
292 val2 == data->variant->regval_to_samp_freq[i][1])
298 static int hmc5843_set_range_gain(struct hmc5843_data *data, u8 range)
302 mutex_lock(&data->lock);
303 ret = regmap_update_bits(data->regmap, HMC5843_CONFIG_REG_B,
304 HMC5843_RANGE_GAIN_MASK,
305 range << HMC5843_RANGE_GAIN_OFFSET);
306 mutex_unlock(&data->lock);
311 static ssize_t hmc5843_show_scale_avail(struct device *dev,
312 struct device_attribute *attr,
315 struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev));
320 for (i = 0; i < data->variant->n_regval_to_nanoscale; i++)
321 len += scnprintf(buf + len, PAGE_SIZE - len,
322 "0.%09d ", data->variant->regval_to_nanoscale[i]);
324 /* replace trailing space by newline */
330 static IIO_DEVICE_ATTR(scale_available, S_IRUGO,
331 hmc5843_show_scale_avail, NULL, 0);
333 static int hmc5843_get_scale_index(struct hmc5843_data *data, int val, int val2)
340 for (i = 0; i < data->variant->n_regval_to_nanoscale; i++)
341 if (val2 == data->variant->regval_to_nanoscale[i])
347 static int hmc5843_read_raw(struct iio_dev *indio_dev,
348 struct iio_chan_spec const *chan,
349 int *val, int *val2, long mask)
351 struct hmc5843_data *data = iio_priv(indio_dev);
356 case IIO_CHAN_INFO_RAW:
357 return hmc5843_read_measurement(data, chan->scan_index, val);
358 case IIO_CHAN_INFO_SCALE:
359 ret = regmap_read(data->regmap, HMC5843_CONFIG_REG_B, &rval);
362 rval >>= HMC5843_RANGE_GAIN_OFFSET;
364 *val2 = data->variant->regval_to_nanoscale[rval];
365 return IIO_VAL_INT_PLUS_NANO;
366 case IIO_CHAN_INFO_SAMP_FREQ:
367 ret = regmap_read(data->regmap, HMC5843_CONFIG_REG_A, &rval);
370 rval >>= HMC5843_RATE_OFFSET;
371 *val = data->variant->regval_to_samp_freq[rval][0];
372 *val2 = data->variant->regval_to_samp_freq[rval][1];
373 return IIO_VAL_INT_PLUS_MICRO;
378 static int hmc5843_write_raw(struct iio_dev *indio_dev,
379 struct iio_chan_spec const *chan,
380 int val, int val2, long mask)
382 struct hmc5843_data *data = iio_priv(indio_dev);
386 case IIO_CHAN_INFO_SAMP_FREQ:
387 rate = hmc5843_get_samp_freq_index(data, val, val2);
391 return hmc5843_set_samp_freq(data, rate);
392 case IIO_CHAN_INFO_SCALE:
393 range = hmc5843_get_scale_index(data, val, val2);
397 return hmc5843_set_range_gain(data, range);
403 static int hmc5843_write_raw_get_fmt(struct iio_dev *indio_dev,
404 struct iio_chan_spec const *chan,
408 case IIO_CHAN_INFO_SAMP_FREQ:
409 return IIO_VAL_INT_PLUS_MICRO;
410 case IIO_CHAN_INFO_SCALE:
411 return IIO_VAL_INT_PLUS_NANO;
417 static irqreturn_t hmc5843_trigger_handler(int irq, void *p)
419 struct iio_poll_func *pf = p;
420 struct iio_dev *indio_dev = pf->indio_dev;
421 struct hmc5843_data *data = iio_priv(indio_dev);
424 mutex_lock(&data->lock);
425 ret = hmc5843_wait_measurement(data);
427 mutex_unlock(&data->lock);
431 ret = regmap_bulk_read(data->regmap, HMC5843_DATA_OUT_MSB_REGS,
432 data->buffer, 3 * sizeof(__be16));
434 mutex_unlock(&data->lock);
438 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
442 iio_trigger_notify_done(indio_dev->trig);
447 #define HMC5843_CHANNEL(axis, idx) \
451 .channel2 = IIO_MOD_##axis, \
452 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
453 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
454 BIT(IIO_CHAN_INFO_SAMP_FREQ), \
460 .endianness = IIO_BE, \
464 static const struct iio_chan_spec hmc5843_channels[] = {
465 HMC5843_CHANNEL(X, 0),
466 HMC5843_CHANNEL(Y, 1),
467 HMC5843_CHANNEL(Z, 2),
468 IIO_CHAN_SOFT_TIMESTAMP(3),
471 /* Beware: Y and Z are exchanged on HMC5883 and 5983 */
472 static const struct iio_chan_spec hmc5883_channels[] = {
473 HMC5843_CHANNEL(X, 0),
474 HMC5843_CHANNEL(Z, 1),
475 HMC5843_CHANNEL(Y, 2),
476 IIO_CHAN_SOFT_TIMESTAMP(3),
479 static struct attribute *hmc5843_attributes[] = {
480 &iio_dev_attr_meas_conf.dev_attr.attr,
481 &iio_dev_attr_scale_available.dev_attr.attr,
482 &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
486 static const struct attribute_group hmc5843_group = {
487 .attrs = hmc5843_attributes,
490 static const struct hmc5843_chip_info hmc5843_chip_info_tbl[] = {
492 .channels = hmc5843_channels,
493 .regval_to_samp_freq = hmc5843_regval_to_samp_freq,
494 .n_regval_to_samp_freq =
495 ARRAY_SIZE(hmc5843_regval_to_samp_freq),
496 .regval_to_nanoscale = hmc5843_regval_to_nanoscale,
497 .n_regval_to_nanoscale =
498 ARRAY_SIZE(hmc5843_regval_to_nanoscale),
501 .channels = hmc5883_channels,
502 .regval_to_samp_freq = hmc5883_regval_to_samp_freq,
503 .n_regval_to_samp_freq =
504 ARRAY_SIZE(hmc5883_regval_to_samp_freq),
505 .regval_to_nanoscale = hmc5883_regval_to_nanoscale,
506 .n_regval_to_nanoscale =
507 ARRAY_SIZE(hmc5883_regval_to_nanoscale),
510 .channels = hmc5883_channels,
511 .regval_to_samp_freq = hmc5883_regval_to_samp_freq,
512 .n_regval_to_samp_freq =
513 ARRAY_SIZE(hmc5883_regval_to_samp_freq),
514 .regval_to_nanoscale = hmc5883l_regval_to_nanoscale,
515 .n_regval_to_nanoscale =
516 ARRAY_SIZE(hmc5883l_regval_to_nanoscale),
519 .channels = hmc5883_channels,
520 .regval_to_samp_freq = hmc5983_regval_to_samp_freq,
521 .n_regval_to_samp_freq =
522 ARRAY_SIZE(hmc5983_regval_to_samp_freq),
523 .regval_to_nanoscale = hmc5883l_regval_to_nanoscale,
524 .n_regval_to_nanoscale =
525 ARRAY_SIZE(hmc5883l_regval_to_nanoscale),
529 static int hmc5843_init(struct hmc5843_data *data)
534 ret = regmap_bulk_read(data->regmap, HMC5843_ID_REG,
538 if (id[0] != 'H' || id[1] != '4' || id[2] != '3') {
539 dev_err(data->dev, "no HMC5843/5883/5883L/5983 sensor\n");
543 ret = hmc5843_set_meas_conf(data, HMC5843_MEAS_CONF_NORMAL);
546 ret = hmc5843_set_samp_freq(data, HMC5843_RATE_DEFAULT);
549 ret = hmc5843_set_range_gain(data, HMC5843_RANGE_GAIN_DEFAULT);
552 return hmc5843_set_mode(data, HMC5843_MODE_CONVERSION_CONTINUOUS);
555 static const struct iio_info hmc5843_info = {
556 .attrs = &hmc5843_group,
557 .read_raw = &hmc5843_read_raw,
558 .write_raw = &hmc5843_write_raw,
559 .write_raw_get_fmt = &hmc5843_write_raw_get_fmt,
560 .driver_module = THIS_MODULE,
563 static const unsigned long hmc5843_scan_masks[] = {0x7, 0};
565 int hmc5843_common_suspend(struct device *dev)
567 return hmc5843_set_mode(iio_priv(dev_get_drvdata(dev)),
568 HMC5843_MODE_CONVERSION_CONTINUOUS);
570 EXPORT_SYMBOL(hmc5843_common_suspend);
572 int hmc5843_common_resume(struct device *dev)
574 return hmc5843_set_mode(iio_priv(dev_get_drvdata(dev)),
577 EXPORT_SYMBOL(hmc5843_common_resume);
579 int hmc5843_common_probe(struct device *dev, struct regmap *regmap,
580 enum hmc5843_ids id, const char *name)
582 struct hmc5843_data *data;
583 struct iio_dev *indio_dev;
586 indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
590 dev_set_drvdata(dev, indio_dev);
592 /* default settings at probe */
593 data = iio_priv(indio_dev);
595 data->regmap = regmap;
596 data->variant = &hmc5843_chip_info_tbl[id];
597 mutex_init(&data->lock);
599 indio_dev->dev.parent = dev;
600 indio_dev->name = name;
601 indio_dev->info = &hmc5843_info;
602 indio_dev->modes = INDIO_DIRECT_MODE;
603 indio_dev->channels = data->variant->channels;
604 indio_dev->num_channels = 4;
605 indio_dev->available_scan_masks = hmc5843_scan_masks;
607 ret = hmc5843_init(data);
611 ret = iio_triggered_buffer_setup(indio_dev, NULL,
612 hmc5843_trigger_handler, NULL);
614 goto buffer_setup_err;
616 ret = iio_device_register(indio_dev);
623 iio_triggered_buffer_cleanup(indio_dev);
625 hmc5843_set_mode(iio_priv(indio_dev), HMC5843_MODE_SLEEP);
628 EXPORT_SYMBOL(hmc5843_common_probe);
630 int hmc5843_common_remove(struct device *dev)
632 struct iio_dev *indio_dev = dev_get_drvdata(dev);
634 iio_device_unregister(indio_dev);
635 iio_triggered_buffer_cleanup(indio_dev);
637 /* sleep mode to save power */
638 hmc5843_set_mode(iio_priv(indio_dev), HMC5843_MODE_SLEEP);
642 EXPORT_SYMBOL(hmc5843_common_remove);
644 MODULE_AUTHOR("Shubhrajyoti Datta <shubhrajyoti@ti.com>");
645 MODULE_DESCRIPTION("HMC5843/5883/5883L/5983 core driver");
646 MODULE_LICENSE("GPL");