1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
|
/* Copyright (C) 2010 Texas Instruments
Author: Shubhrajyoti Datta <shubhrajyoti@ti.com>
Acknowledgement: Jonathan Cameron <jic23@kernel.org> for valuable inputs.
Support for HMC5883 and HMC5883L by Peter Meerwald <pmeerw@pmeerw.net>.
Split to multiple files by Josef Gajdusek <atx@atx.name> - 2014
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/delay.h>
#include "hmc5843.h"
/*
* Range gain settings in (+-)Ga
* Beware: HMC5843 and HMC5883 have different recommended sensor field
* ranges; default corresponds to +-1.0 Ga and +-1.3 Ga, respectively
*/
#define HMC5843_RANGE_GAIN_OFFSET 0x05
#define HMC5843_RANGE_GAIN_DEFAULT 0x01
#define HMC5843_RANGE_GAINS 8
#define HMC5843_RANGE_GAIN_MASK 0xe0
/* Device status */
#define HMC5843_DATA_READY 0x01
#define HMC5843_DATA_OUTPUT_LOCK 0x02
/* Mode register configuration */
#define HMC5843_MODE_CONVERSION_CONTINUOUS 0x00
#define HMC5843_MODE_CONVERSION_SINGLE 0x01
#define HMC5843_MODE_IDLE 0x02
#define HMC5843_MODE_SLEEP 0x03
#define HMC5843_MODE_MASK 0x03
/*
* HMC5843: Minimum data output rate
* HMC5883: Typical data output rate
*/
#define HMC5843_RATE_OFFSET 0x02
#define HMC5843_RATE_DEFAULT 0x04
#define HMC5843_RATES 7
#define HMC5843_RATE_MASK 0x1c
/* Device measurement configuration */
#define HMC5843_MEAS_CONF_NORMAL 0x00
#define HMC5843_MEAS_CONF_POSITIVE_BIAS 0x01
#define HMC5843_MEAS_CONF_NEGATIVE_BIAS 0x02
#define HMC5843_MEAS_CONF_MASK 0x03
/* Scaling factors: 10000000/Gain */
static const int hmc5843_regval_to_nanoscale[HMC5843_RANGE_GAINS] = {
6173, 7692, 10309, 12821, 18868, 21739, 25641, 35714
};
static const int hmc5883_regval_to_nanoscale[HMC5843_RANGE_GAINS] = {
7812, 9766, 13021, 16287, 24096, 27701, 32573, 45662
};
static const int hmc5883l_regval_to_nanoscale[HMC5843_RANGE_GAINS] = {
7299, 9174, 12195, 15152, 22727, 25641, 30303, 43478
};
/*
* From the datasheet:
* Value | HMC5843 | HMC5883/HMC5883L
* | Data output rate (Hz) | Data output rate (Hz)
* 0 | 0.5 | 0.75
* 1 | 1 | 1.5
* 2 | 2 | 3
* 3 | 5 | 7.5
* 4 | 10 (default) | 15
* 5 | 20 | 30
* 6 | 50 | 75
* 7 | Not used | Not used
*/
static const int hmc5843_regval_to_samp_freq[7][2] = {
{0, 500000}, {1, 0}, {2, 0}, {5, 0}, {10, 0}, {20, 0}, {50, 0}
};
static const int hmc5883_regval_to_samp_freq[7][2] = {
{0, 750000}, {1, 500000}, {3, 0}, {7, 500000}, {15, 0}, {30, 0},
{75, 0}
};
/* Describe chip variants */
struct hmc5843_chip_info {
const struct iio_chan_spec *channels;
const int (*regval_to_samp_freq)[2];
const int *regval_to_nanoscale;
};
/* The lower two bits contain the current conversion mode */
static s32 hmc5843_set_mode(struct hmc5843_data *data, u8 operating_mode)
{
int ret;
mutex_lock(&data->lock);
ret = regmap_update_bits(data->regmap, HMC5843_MODE_REG,
HMC5843_MODE_MASK, operating_mode);
mutex_unlock(&data->lock);
return ret;
}
static int hmc5843_wait_measurement(struct hmc5843_data *data)
{
int tries = 150;
int val;
int ret;
while (tries-- > 0) {
ret = regmap_read(data->regmap, HMC5843_STATUS_REG, &val);
if (ret < 0)
return ret;
if (val & HMC5843_DATA_READY)
break;
msleep(20);
}
if (tries < 0) {
dev_err(data->dev, "data not ready\n");
return -EIO;
}
return 0;
}
/* Return the measurement value from the specified channel */
static int hmc5843_read_measurement(struct hmc5843_data *data,
int idx, int *val)
{
__be16 values[3];
int ret;
mutex_lock(&data->lock);
ret = hmc5843_wait_measurement(data);
if (ret < 0) {
mutex_unlock(&data->lock);
return ret;
}
ret = regmap_bulk_read(data->regmap, HMC5843_DATA_OUT_MSB_REGS,
values, sizeof(values));
mutex_unlock(&data->lock);
if (ret < 0)
return ret;
*val = sign_extend32(be16_to_cpu(values[idx]), 15);
return IIO_VAL_INT;
}
/*
* API for setting the measurement configuration to
* Normal, Positive bias and Negative bias
*
* From the datasheet:
* 0 - Normal measurement configuration (default): In normal measurement
* configuration the device follows normal measurement flow. Pins BP
* and BN are left floating and high impedance.
*
* 1 - Positive bias configuration: In positive bias configuration, a
* positive current is forced across the resistive load on pins BP
* and BN.
*
* 2 - Negative bias configuration. In negative bias configuration, a
* negative current is forced across the resistive load on pins BP
* and BN.
*
*/
static int hmc5843_set_meas_conf(struct hmc5843_data *data, u8 meas_conf)
{
int ret;
mutex_lock(&data->lock);
ret = regmap_update_bits(data->regmap, HMC5843_CONFIG_REG_A,
HMC5843_MEAS_CONF_MASK, meas_conf);
mutex_unlock(&data->lock);
return ret;
}
static ssize_t hmc5843_show_measurement_configuration(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev));
int val;
int ret;
ret = regmap_read(data->regmap, HMC5843_CONFIG_REG_A, &val);
if (ret)
return ret;
val &= HMC5843_MEAS_CONF_MASK;
return sprintf(buf, "%d\n", val);
}
static ssize_t hmc5843_set_measurement_configuration(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev));
unsigned long meas_conf = 0;
int ret;
ret = kstrtoul(buf, 10, &meas_conf);
if (ret)
return ret;
if (meas_conf >= HMC5843_MEAS_CONF_MASK)
return -EINVAL;
ret = hmc5843_set_meas_conf(data, meas_conf);
return (ret < 0) ? ret : count;
}
static IIO_DEVICE_ATTR(meas_conf,
S_IWUSR | S_IRUGO,
hmc5843_show_measurement_configuration,
hmc5843_set_measurement_configuration,
0);
static ssize_t hmc5843_show_samp_freq_avail(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev));
size_t len = 0;
int i;
for (i = 0; i < HMC5843_RATES; i++)
len += scnprintf(buf + len, PAGE_SIZE - len,
"%d.%d ", data->variant->regval_to_samp_freq[i][0],
data->variant->regval_to_samp_freq[i][1]);
/* replace trailing space by newline */
buf[len - 1] = '\n';
return len;
}
static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(hmc5843_show_samp_freq_avail);
static int hmc5843_set_samp_freq(struct hmc5843_data *data, u8 rate)
{
int ret;
mutex_lock(&data->lock);
ret = regmap_update_bits(data->regmap, HMC5843_CONFIG_REG_A,
HMC5843_RATE_MASK, rate << HMC5843_RATE_OFFSET);
mutex_unlock(&data->lock);
return ret;
}
static int hmc5843_get_samp_freq_index(struct hmc5843_data *data,
int val, int val2)
{
int i;
for (i = 0; i < HMC5843_RATES; i++)
if (val == data->variant->regval_to_samp_freq[i][0] &&
val2 == data->variant->regval_to_samp_freq[i][1])
return i;
return -EINVAL;
}
static int hmc5843_set_range_gain(struct hmc5843_data *data, u8 range)
{
int ret;
mutex_lock(&data->lock);
ret = regmap_update_bits(data->regmap, HMC5843_CONFIG_REG_B,
HMC5843_RANGE_GAIN_MASK,
range << HMC5843_RANGE_GAIN_OFFSET);
mutex_unlock(&data->lock);
return ret;
}
static ssize_t hmc5843_show_scale_avail(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev));
size_t len = 0;
int i;
for (i = 0; i < HMC5843_RANGE_GAINS; i++)
len += scnprintf(buf + len, PAGE_SIZE - len,
"0.%09d ", data->variant->regval_to_nanoscale[i]);
/* replace trailing space by newline */
buf[len - 1] = '\n';
return len;
}
static IIO_DEVICE_ATTR(scale_available, S_IRUGO,
hmc5843_show_scale_avail, NULL, 0);
static int hmc5843_get_scale_index(struct hmc5843_data *data, int val, int val2)
{
int i;
if (val != 0)
return -EINVAL;
for (i = 0; i < HMC5843_RANGE_GAINS; i++)
if (val2 == data->variant->regval_to_nanoscale[i])
return i;
return -EINVAL;
}
static int hmc5843_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct hmc5843_data *data = iio_priv(indio_dev);
int rval;
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
return hmc5843_read_measurement(data, chan->scan_index, val);
case IIO_CHAN_INFO_SCALE:
ret = regmap_read(data->regmap, HMC5843_CONFIG_REG_B, &rval);
if (ret < 0)
return ret;
rval >>= HMC5843_RANGE_GAIN_OFFSET;
*val = 0;
*val2 = data->variant->regval_to_nanoscale[rval];
return IIO_VAL_INT_PLUS_NANO;
case IIO_CHAN_INFO_SAMP_FREQ:
ret = regmap_read(data->regmap, HMC5843_CONFIG_REG_A, &rval);
if (ret < 0)
return ret;
rval >>= HMC5843_RATE_OFFSET;
*val = data->variant->regval_to_samp_freq[rval][0];
*val2 = data->variant->regval_to_samp_freq[rval][1];
return IIO_VAL_INT_PLUS_MICRO;
}
return -EINVAL;
}
static int hmc5843_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct hmc5843_data *data = iio_priv(indio_dev);
int rate, range;
switch (mask) {
case IIO_CHAN_INFO_SAMP_FREQ:
rate = hmc5843_get_samp_freq_index(data, val, val2);
if (rate < 0)
return -EINVAL;
return hmc5843_set_samp_freq(data, rate);
case IIO_CHAN_INFO_SCALE:
range = hmc5843_get_scale_index(data, val, val2);
if (range < 0)
return -EINVAL;
return hmc5843_set_range_gain(data, range);
default:
return -EINVAL;
}
}
static int hmc5843_write_raw_get_fmt(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, long mask)
{
switch (mask) {
case IIO_CHAN_INFO_SAMP_FREQ:
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_SCALE:
return IIO_VAL_INT_PLUS_NANO;
default:
return -EINVAL;
}
}
static irqreturn_t hmc5843_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct hmc5843_data *data = iio_priv(indio_dev);
int ret;
mutex_lock(&data->lock);
ret = hmc5843_wait_measurement(data);
if (ret < 0) {
mutex_unlock(&data->lock);
goto done;
}
ret = regmap_bulk_read(data->regmap, HMC5843_DATA_OUT_MSB_REGS,
data->buffer, 3 * sizeof(__be16));
mutex_unlock(&data->lock);
if (ret < 0)
goto done;
iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
iio_get_time_ns());
done:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
#define HMC5843_CHANNEL(axis, idx) \
{ \
.type = IIO_MAGN, \
.modified = 1, \
.channel2 = IIO_MOD_##axis, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_SAMP_FREQ), \
.scan_index = idx, \
.scan_type = { \
.sign = 's', \
.realbits = 16, \
.storagebits = 16, \
.endianness = IIO_BE, \
}, \
}
static const struct iio_chan_spec hmc5843_channels[] = {
HMC5843_CHANNEL(X, 0),
HMC5843_CHANNEL(Y, 1),
HMC5843_CHANNEL(Z, 2),
IIO_CHAN_SOFT_TIMESTAMP(3),
};
/* Beware: Y and Z are exchanged on HMC5883 */
static const struct iio_chan_spec hmc5883_channels[] = {
HMC5843_CHANNEL(X, 0),
HMC5843_CHANNEL(Z, 1),
HMC5843_CHANNEL(Y, 2),
IIO_CHAN_SOFT_TIMESTAMP(3),
};
static struct attribute *hmc5843_attributes[] = {
&iio_dev_attr_meas_conf.dev_attr.attr,
&iio_dev_attr_scale_available.dev_attr.attr,
&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
NULL
};
static const struct attribute_group hmc5843_group = {
.attrs = hmc5843_attributes,
};
static const struct hmc5843_chip_info hmc5843_chip_info_tbl[] = {
[HMC5843_ID] = {
.channels = hmc5843_channels,
.regval_to_samp_freq = hmc5843_regval_to_samp_freq,
.regval_to_nanoscale = hmc5843_regval_to_nanoscale,
},
[HMC5883_ID] = {
.channels = hmc5883_channels,
.regval_to_samp_freq = hmc5883_regval_to_samp_freq,
.regval_to_nanoscale = hmc5883_regval_to_nanoscale,
},
[HMC5883L_ID] = {
.channels = hmc5883_channels,
.regval_to_samp_freq = hmc5883_regval_to_samp_freq,
.regval_to_nanoscale = hmc5883l_regval_to_nanoscale,
},
};
static int hmc5843_init(struct hmc5843_data *data)
{
int ret;
u8 id[3];
ret = regmap_bulk_read(data->regmap, HMC5843_ID_REG,
id, ARRAY_SIZE(id));
if (ret < 0)
return ret;
if (id[0] != 'H' || id[1] != '4' || id[2] != '3') {
dev_err(data->dev, "no HMC5843/5883/5883L sensor\n");
return -ENODEV;
}
ret = hmc5843_set_meas_conf(data, HMC5843_MEAS_CONF_NORMAL);
if (ret < 0)
return ret;
ret = hmc5843_set_samp_freq(data, HMC5843_RATE_DEFAULT);
if (ret < 0)
return ret;
ret = hmc5843_set_range_gain(data, HMC5843_RANGE_GAIN_DEFAULT);
if (ret < 0)
return ret;
return hmc5843_set_mode(data, HMC5843_MODE_CONVERSION_CONTINUOUS);
}
static const struct iio_info hmc5843_info = {
.attrs = &hmc5843_group,
.read_raw = &hmc5843_read_raw,
.write_raw = &hmc5843_write_raw,
.write_raw_get_fmt = &hmc5843_write_raw_get_fmt,
.driver_module = THIS_MODULE,
};
static const unsigned long hmc5843_scan_masks[] = {0x7, 0};
int hmc5843_common_suspend(struct device *dev)
{
return hmc5843_set_mode(iio_priv(dev_get_drvdata(dev)),
HMC5843_MODE_CONVERSION_CONTINUOUS);
}
EXPORT_SYMBOL(hmc5843_common_suspend);
int hmc5843_common_resume(struct device *dev)
{
return hmc5843_set_mode(iio_priv(dev_get_drvdata(dev)),
HMC5843_MODE_SLEEP);
}
EXPORT_SYMBOL(hmc5843_common_resume);
int hmc5843_common_probe(struct device *dev, struct regmap *regmap,
enum hmc5843_ids id)
{
struct hmc5843_data *data;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
if (indio_dev == NULL)
return -ENOMEM;
dev_set_drvdata(dev, indio_dev);
/* default settings at probe */
data = iio_priv(indio_dev);
data->dev = dev;
data->regmap = regmap;
data->variant = &hmc5843_chip_info_tbl[id];
mutex_init(&data->lock);
indio_dev->dev.parent = dev;
indio_dev->info = &hmc5843_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = data->variant->channels;
indio_dev->num_channels = 4;
indio_dev->available_scan_masks = hmc5843_scan_masks;
ret = hmc5843_init(data);
if (ret < 0)
return ret;
ret = iio_triggered_buffer_setup(indio_dev, NULL,
hmc5843_trigger_handler, NULL);
if (ret < 0)
return ret;
ret = iio_device_register(indio_dev);
if (ret < 0)
goto buffer_cleanup;
return 0;
buffer_cleanup:
iio_triggered_buffer_cleanup(indio_dev);
return ret;
}
EXPORT_SYMBOL(hmc5843_common_probe);
int hmc5843_common_remove(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
iio_device_unregister(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
/* sleep mode to save power */
hmc5843_set_mode(iio_priv(indio_dev), HMC5843_MODE_SLEEP);
return 0;
}
EXPORT_SYMBOL(hmc5843_common_remove);
MODULE_AUTHOR("Shubhrajyoti Datta <shubhrajyoti@ti.com>");
MODULE_DESCRIPTION("HMC5843/5883/5883L core driver");
MODULE_LICENSE("GPL");
|