1 /* Copyright (C) 2010 Texas Instruments
2 Author: Shubhrajyoti Datta <shubhrajyoti@ti.com>
3 Acknowledgement: Jonathan Cameron <jic23@kernel.org> for valuable inputs.
5 Support for HMC5883 and HMC5883L by Peter Meerwald <pmeerw@pmeerw.net>.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 #include <linux/module.h>
23 #include <linux/i2c.h>
24 #include <linux/iio/iio.h>
25 #include <linux/iio/sysfs.h>
26 #include <linux/iio/trigger_consumer.h>
27 #include <linux/iio/buffer.h>
28 #include <linux/iio/triggered_buffer.h>
29 #include <linux/delay.h>
31 #define HMC5843_CONFIG_REG_A 0x00
32 #define HMC5843_CONFIG_REG_B 0x01
33 #define HMC5843_MODE_REG 0x02
34 #define HMC5843_DATA_OUT_MSB_REGS 0x03
35 #define HMC5843_STATUS_REG 0x09
36 #define HMC5843_ID_REG 0x0a
45 * Range gain settings in (+-)Ga
46 * Beware: HMC5843 and HMC5883 have different recommended sensor field
47 * ranges; default corresponds to +-1.0 Ga and +-1.3 Ga, respectively
49 #define HMC5843_RANGE_GAIN_OFFSET 0x05
50 #define HMC5843_RANGE_GAIN_DEFAULT 0x01
51 #define HMC5843_RANGE_GAINS 8
54 #define HMC5843_DATA_READY 0x01
55 #define HMC5843_DATA_OUTPUT_LOCK 0x02
57 /* Mode register configuration */
58 #define HMC5843_MODE_CONVERSION_CONTINUOUS 0x00
59 #define HMC5843_MODE_CONVERSION_SINGLE 0x01
60 #define HMC5843_MODE_IDLE 0x02
61 #define HMC5843_MODE_SLEEP 0x03
62 #define HMC5843_MODE_MASK 0x03
65 * HMC5843: Minimum data output rate
66 * HMC5883: Typical data output rate
68 #define HMC5843_RATE_OFFSET 0x02
69 #define HMC5843_RATE_DEFAULT 0x04
70 #define HMC5843_RATES 7
72 /* Device measurement configuration */
73 #define HMC5843_MEAS_CONF_NORMAL 0x00
74 #define HMC5843_MEAS_CONF_POSITIVE_BIAS 0x01
75 #define HMC5843_MEAS_CONF_NEGATIVE_BIAS 0x02
76 #define HMC5843_MEAS_CONF_MASK 0x03
78 /* Scaling factors: 10000000/Gain */
79 static const int hmc5843_regval_to_nanoscale
[HMC5843_RANGE_GAINS
] = {
80 6173, 7692, 10309, 12821, 18868, 21739, 25641, 35714
83 static const int hmc5883_regval_to_nanoscale
[HMC5843_RANGE_GAINS
] = {
84 7812, 9766, 13021, 16287, 24096, 27701, 32573, 45662
87 static const int hmc5883l_regval_to_nanoscale
[HMC5843_RANGE_GAINS
] = {
88 7299, 9174, 12195, 15152, 22727, 25641, 30303, 43478
93 * Value | HMC5843 | HMC5883/HMC5883L
94 * | Data output rate (Hz) | Data output rate (Hz)
99 * 4 | 10 (default) | 15
102 * 7 | Not used | Not used
104 static const int hmc5843_regval_to_samp_freq
[7][2] = {
105 {0, 500000}, {1, 0}, {2, 0}, {5, 0}, {10, 0}, {20, 0}, {50, 0}
108 static const int hmc5883_regval_to_samp_freq
[7][2] = {
109 {0, 750000}, {1, 500000}, {3, 0}, {7, 500000}, {15, 0}, {30, 0},
113 /* Describe chip variants */
114 struct hmc5843_chip_info
{
115 const struct iio_chan_spec
*channels
;
116 const int (*regval_to_samp_freq
)[2];
117 const int *regval_to_nanoscale
;
120 /* Each client has this additional data */
121 struct hmc5843_data
{
122 struct i2c_client
*client
;
128 const struct hmc5843_chip_info
*variant
;
129 __be16 buffer
[8]; /* 3x 16-bit channels + padding + 64-bit timestamp */
132 /* The lower two bits contain the current conversion mode */
133 static s32
hmc5843_set_mode(struct hmc5843_data
*data
, u8 operating_mode
)
137 mutex_lock(&data
->lock
);
138 ret
= i2c_smbus_write_byte_data(data
->client
, HMC5843_MODE_REG
,
139 operating_mode
& HMC5843_MODE_MASK
);
141 data
->operating_mode
= operating_mode
;
142 mutex_unlock(&data
->lock
);
147 static int hmc5843_wait_measurement(struct hmc5843_data
*data
)
152 while (tries
-- > 0) {
153 result
= i2c_smbus_read_byte_data(data
->client
,
157 if (result
& HMC5843_DATA_READY
)
163 dev_err(&data
->client
->dev
, "data not ready\n");
170 /* Return the measurement value from the specified channel */
171 static int hmc5843_read_measurement(struct hmc5843_data
*data
,
177 mutex_lock(&data
->lock
);
178 result
= hmc5843_wait_measurement(data
);
180 mutex_unlock(&data
->lock
);
183 result
= i2c_smbus_read_i2c_block_data(data
->client
,
184 HMC5843_DATA_OUT_MSB_REGS
, sizeof(values
), (u8
*) values
);
185 mutex_unlock(&data
->lock
);
189 *val
= sign_extend32(be16_to_cpu(values
[idx
]), 15);
194 * API for setting the measurement configuration to
195 * Normal, Positive bias and Negative bias
197 * From the datasheet:
198 * 0 - Normal measurement configuration (default): In normal measurement
199 * configuration the device follows normal measurement flow. Pins BP
200 * and BN are left floating and high impedance.
202 * 1 - Positive bias configuration: In positive bias configuration, a
203 * positive current is forced across the resistive load on pins BP
206 * 2 - Negative bias configuration. In negative bias configuration, a
207 * negative current is forced across the resistive load on pins BP
211 static s32
hmc5843_set_meas_conf(struct hmc5843_data
*data
, u8 meas_conf
)
215 mutex_lock(&data
->lock
);
216 ret
= i2c_smbus_write_byte_data(data
->client
, HMC5843_CONFIG_REG_A
,
217 (meas_conf
& HMC5843_MEAS_CONF_MASK
) |
218 (data
->rate
<< HMC5843_RATE_OFFSET
));
220 data
->meas_conf
= meas_conf
;
221 mutex_unlock(&data
->lock
);
226 static ssize_t
hmc5843_show_measurement_configuration(struct device
*dev
,
227 struct device_attribute
*attr
,
230 struct hmc5843_data
*data
= iio_priv(dev_to_iio_dev(dev
));
231 return sprintf(buf
, "%d\n", data
->meas_conf
);
234 static ssize_t
hmc5843_set_measurement_configuration(struct device
*dev
,
235 struct device_attribute
*attr
,
239 struct hmc5843_data
*data
= iio_priv(dev_to_iio_dev(dev
));
240 unsigned long meas_conf
= 0;
243 ret
= kstrtoul(buf
, 10, &meas_conf
);
246 if (meas_conf
>= HMC5843_MEAS_CONF_MASK
)
249 ret
= hmc5843_set_meas_conf(data
, meas_conf
);
251 return (ret
< 0) ? ret
: count
;
254 static IIO_DEVICE_ATTR(meas_conf
,
256 hmc5843_show_measurement_configuration
,
257 hmc5843_set_measurement_configuration
,
260 static ssize_t
hmc5843_show_samp_freq_avail(struct device
*dev
,
261 struct device_attribute
*attr
, char *buf
)
263 struct hmc5843_data
*data
= iio_priv(dev_to_iio_dev(dev
));
267 for (i
= 0; i
< HMC5843_RATES
; i
++)
268 len
+= scnprintf(buf
+ len
, PAGE_SIZE
- len
,
269 "%d.%d ", data
->variant
->regval_to_samp_freq
[i
][0],
270 data
->variant
->regval_to_samp_freq
[i
][1]);
272 /* replace trailing space by newline */
278 static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(hmc5843_show_samp_freq_avail
);
280 static int hmc5843_set_samp_freq(struct hmc5843_data
*data
, u8 rate
)
284 mutex_lock(&data
->lock
);
285 ret
= i2c_smbus_write_byte_data(data
->client
, HMC5843_CONFIG_REG_A
,
286 data
->meas_conf
| (rate
<< HMC5843_RATE_OFFSET
));
289 mutex_unlock(&data
->lock
);
294 static int hmc5843_get_samp_freq_index(struct hmc5843_data
*data
,
299 for (i
= 0; i
< HMC5843_RATES
; i
++)
300 if (val
== data
->variant
->regval_to_samp_freq
[i
][0] &&
301 val2
== data
->variant
->regval_to_samp_freq
[i
][1])
307 static int hmc5843_set_range_gain(struct hmc5843_data
*data
, u8 range
)
311 mutex_lock(&data
->lock
);
312 ret
= i2c_smbus_write_byte_data(data
->client
, HMC5843_CONFIG_REG_B
,
313 range
<< HMC5843_RANGE_GAIN_OFFSET
);
316 mutex_unlock(&data
->lock
);
321 static ssize_t
hmc5843_show_scale_avail(struct device
*dev
,
322 struct device_attribute
*attr
, char *buf
)
324 struct hmc5843_data
*data
= iio_priv(dev_to_iio_dev(dev
));
329 for (i
= 0; i
< HMC5843_RANGE_GAINS
; i
++)
330 len
+= scnprintf(buf
+ len
, PAGE_SIZE
- len
,
331 "0.%09d ", data
->variant
->regval_to_nanoscale
[i
]);
333 /* replace trailing space by newline */
339 static IIO_DEVICE_ATTR(scale_available
, S_IRUGO
,
340 hmc5843_show_scale_avail
, NULL
, 0);
342 static int hmc5843_get_scale_index(struct hmc5843_data
*data
, int val
, int val2
)
349 for (i
= 0; i
< HMC5843_RANGE_GAINS
; i
++)
350 if (val2
== data
->variant
->regval_to_nanoscale
[i
])
356 static int hmc5843_read_raw(struct iio_dev
*indio_dev
,
357 struct iio_chan_spec
const *chan
,
358 int *val
, int *val2
, long mask
)
360 struct hmc5843_data
*data
= iio_priv(indio_dev
);
363 case IIO_CHAN_INFO_RAW
:
364 return hmc5843_read_measurement(data
, chan
->scan_index
, val
);
365 case IIO_CHAN_INFO_SCALE
:
367 *val2
= data
->variant
->regval_to_nanoscale
[data
->range
];
368 return IIO_VAL_INT_PLUS_NANO
;
369 case IIO_CHAN_INFO_SAMP_FREQ
:
370 *val
= data
->variant
->regval_to_samp_freq
[data
->rate
][0];
371 *val2
= data
->variant
->regval_to_samp_freq
[data
->rate
][1];
372 return IIO_VAL_INT_PLUS_MICRO
;
377 static int hmc5843_write_raw(struct iio_dev
*indio_dev
,
378 struct iio_chan_spec
const *chan
,
379 int val
, int val2
, long mask
)
381 struct hmc5843_data
*data
= iio_priv(indio_dev
);
385 case IIO_CHAN_INFO_SAMP_FREQ
:
386 rate
= hmc5843_get_samp_freq_index(data
, val
, val2
);
390 return hmc5843_set_samp_freq(data
, rate
);
391 case IIO_CHAN_INFO_SCALE
:
392 range
= hmc5843_get_scale_index(data
, val
, val2
);
396 return hmc5843_set_range_gain(data
, range
);
402 static int hmc5843_write_raw_get_fmt(struct iio_dev
*indio_dev
,
403 struct iio_chan_spec
const *chan
, long mask
)
406 case IIO_CHAN_INFO_SAMP_FREQ
:
407 return IIO_VAL_INT_PLUS_MICRO
;
408 case IIO_CHAN_INFO_SCALE
:
409 return IIO_VAL_INT_PLUS_NANO
;
415 static irqreturn_t
hmc5843_trigger_handler(int irq
, void *p
)
417 struct iio_poll_func
*pf
= p
;
418 struct iio_dev
*indio_dev
= pf
->indio_dev
;
419 struct hmc5843_data
*data
= iio_priv(indio_dev
);
422 mutex_lock(&data
->lock
);
423 ret
= hmc5843_wait_measurement(data
);
425 mutex_unlock(&data
->lock
);
429 ret
= i2c_smbus_read_i2c_block_data(data
->client
,
430 HMC5843_DATA_OUT_MSB_REGS
, 3 * sizeof(__be16
),
431 (u8
*) data
->buffer
);
432 mutex_unlock(&data
->lock
);
436 iio_push_to_buffers_with_timestamp(indio_dev
, data
->buffer
,
440 iio_trigger_notify_done(indio_dev
->trig
);
445 #define HMC5843_CHANNEL(axis, idx) \
449 .channel2 = IIO_MOD_##axis, \
450 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
451 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
452 BIT(IIO_CHAN_INFO_SAMP_FREQ), \
458 .endianness = IIO_BE, \
462 static const struct iio_chan_spec hmc5843_channels
[] = {
463 HMC5843_CHANNEL(X
, 0),
464 HMC5843_CHANNEL(Y
, 1),
465 HMC5843_CHANNEL(Z
, 2),
466 IIO_CHAN_SOFT_TIMESTAMP(3),
469 /* Beware: Y and Z are exchanged on HMC5883 */
470 static const struct iio_chan_spec hmc5883_channels
[] = {
471 HMC5843_CHANNEL(X
, 0),
472 HMC5843_CHANNEL(Z
, 1),
473 HMC5843_CHANNEL(Y
, 2),
474 IIO_CHAN_SOFT_TIMESTAMP(3),
477 static struct attribute
*hmc5843_attributes
[] = {
478 &iio_dev_attr_meas_conf
.dev_attr
.attr
,
479 &iio_dev_attr_scale_available
.dev_attr
.attr
,
480 &iio_dev_attr_sampling_frequency_available
.dev_attr
.attr
,
484 static const struct attribute_group hmc5843_group
= {
485 .attrs
= hmc5843_attributes
,
488 static const struct hmc5843_chip_info hmc5843_chip_info_tbl
[] = {
490 .channels
= hmc5843_channels
,
491 .regval_to_samp_freq
= hmc5843_regval_to_samp_freq
,
492 .regval_to_nanoscale
= hmc5843_regval_to_nanoscale
,
495 .channels
= hmc5883_channels
,
496 .regval_to_samp_freq
= hmc5883_regval_to_samp_freq
,
497 .regval_to_nanoscale
= hmc5883_regval_to_nanoscale
,
500 .channels
= hmc5883_channels
,
501 .regval_to_samp_freq
= hmc5883_regval_to_samp_freq
,
502 .regval_to_nanoscale
= hmc5883l_regval_to_nanoscale
,
506 static int hmc5843_init(struct hmc5843_data
*data
)
511 ret
= i2c_smbus_read_i2c_block_data(data
->client
, HMC5843_ID_REG
,
515 if (id
[0] != 'H' || id
[1] != '4' || id
[2] != '3') {
516 dev_err(&data
->client
->dev
, "no HMC5843/5883/5883L sensor\n");
520 ret
= hmc5843_set_meas_conf(data
, HMC5843_MEAS_CONF_NORMAL
);
523 ret
= hmc5843_set_samp_freq(data
, HMC5843_RATE_DEFAULT
);
526 ret
= hmc5843_set_range_gain(data
, HMC5843_RANGE_GAIN_DEFAULT
);
529 return hmc5843_set_mode(data
, HMC5843_MODE_CONVERSION_CONTINUOUS
);
532 static const struct iio_info hmc5843_info
= {
533 .attrs
= &hmc5843_group
,
534 .read_raw
= &hmc5843_read_raw
,
535 .write_raw
= &hmc5843_write_raw
,
536 .write_raw_get_fmt
= &hmc5843_write_raw_get_fmt
,
537 .driver_module
= THIS_MODULE
,
540 static const unsigned long hmc5843_scan_masks
[] = {0x7, 0};
542 static int hmc5843_probe(struct i2c_client
*client
,
543 const struct i2c_device_id
*id
)
545 struct hmc5843_data
*data
;
546 struct iio_dev
*indio_dev
;
549 indio_dev
= devm_iio_device_alloc(&client
->dev
, sizeof(*data
));
550 if (indio_dev
== NULL
)
553 /* default settings at probe */
554 data
= iio_priv(indio_dev
);
555 data
->client
= client
;
556 data
->variant
= &hmc5843_chip_info_tbl
[id
->driver_data
];
557 mutex_init(&data
->lock
);
559 i2c_set_clientdata(client
, indio_dev
);
560 indio_dev
->info
= &hmc5843_info
;
561 indio_dev
->name
= id
->name
;
562 indio_dev
->dev
.parent
= &client
->dev
;
563 indio_dev
->modes
= INDIO_DIRECT_MODE
;
564 indio_dev
->channels
= data
->variant
->channels
;
565 indio_dev
->num_channels
= 4;
566 indio_dev
->available_scan_masks
= hmc5843_scan_masks
;
568 ret
= hmc5843_init(data
);
572 ret
= iio_triggered_buffer_setup(indio_dev
, NULL
,
573 hmc5843_trigger_handler
, NULL
);
577 ret
= iio_device_register(indio_dev
);
584 iio_triggered_buffer_cleanup(indio_dev
);
588 static int hmc5843_remove(struct i2c_client
*client
)
590 struct iio_dev
*indio_dev
= i2c_get_clientdata(client
);
592 iio_device_unregister(indio_dev
);
593 iio_triggered_buffer_cleanup(indio_dev
);
595 /* sleep mode to save power */
596 hmc5843_set_mode(iio_priv(indio_dev
), HMC5843_MODE_SLEEP
);
601 #ifdef CONFIG_PM_SLEEP
602 static int hmc5843_suspend(struct device
*dev
)
604 struct hmc5843_data
*data
= iio_priv(i2c_get_clientdata(
605 to_i2c_client(dev
)));
607 return hmc5843_set_mode(data
, HMC5843_MODE_SLEEP
);
610 static int hmc5843_resume(struct device
*dev
)
612 struct hmc5843_data
*data
= iio_priv(i2c_get_clientdata(
613 to_i2c_client(dev
)));
615 return hmc5843_set_mode(data
, HMC5843_MODE_CONVERSION_CONTINUOUS
);
618 static SIMPLE_DEV_PM_OPS(hmc5843_pm_ops
, hmc5843_suspend
, hmc5843_resume
);
619 #define HMC5843_PM_OPS (&hmc5843_pm_ops)
621 #define HMC5843_PM_OPS NULL
624 static const struct i2c_device_id hmc5843_id
[] = {
625 { "hmc5843", HMC5843_ID
},
626 { "hmc5883", HMC5883_ID
},
627 { "hmc5883l", HMC5883L_ID
},
630 MODULE_DEVICE_TABLE(i2c
, hmc5843_id
);
632 static struct i2c_driver hmc5843_driver
= {
635 .pm
= HMC5843_PM_OPS
,
637 .id_table
= hmc5843_id
,
638 .probe
= hmc5843_probe
,
639 .remove
= hmc5843_remove
,
641 module_i2c_driver(hmc5843_driver
);
643 MODULE_AUTHOR("Shubhrajyoti Datta <shubhrajyoti@ti.com>");
644 MODULE_DESCRIPTION("HMC5843/5883/5883L driver");
645 MODULE_LICENSE("GPL");