1 // SPDX-License-Identifier: GPL-2.0-only
3 * Sensortek STK8312 3-Axis Accelerometer
5 * Copyright (c) 2015, Intel Corporation.
7 * IIO driver for STK8312; 7-bit I2C address: 0x3D.
10 #include <linux/i2c.h>
11 #include <linux/interrupt.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/delay.h>
15 #include <linux/types.h>
16 #include <linux/iio/buffer.h>
17 #include <linux/iio/iio.h>
18 #include <linux/iio/sysfs.h>
19 #include <linux/iio/trigger.h>
20 #include <linux/iio/triggered_buffer.h>
21 #include <linux/iio/trigger_consumer.h>
23 #define STK8312_REG_XOUT 0x00
24 #define STK8312_REG_YOUT 0x01
25 #define STK8312_REG_ZOUT 0x02
26 #define STK8312_REG_INTSU 0x06
27 #define STK8312_REG_MODE 0x07
28 #define STK8312_REG_SR 0x08
29 #define STK8312_REG_STH 0x13
30 #define STK8312_REG_RESET 0x20
31 #define STK8312_REG_AFECTRL 0x24
32 #define STK8312_REG_OTPADDR 0x3D
33 #define STK8312_REG_OTPDATA 0x3E
34 #define STK8312_REG_OTPCTRL 0x3F
36 #define STK8312_MODE_ACTIVE BIT(0)
37 #define STK8312_MODE_STANDBY 0x00
38 #define STK8312_MODE_INT_AH_PP 0xC0 /* active-high, push-pull */
39 #define STK8312_DREADY_BIT BIT(4)
40 #define STK8312_RNG_6G 1
41 #define STK8312_RNG_SHIFT 6
42 #define STK8312_RNG_MASK GENMASK(7, 6)
43 #define STK8312_SR_MASK GENMASK(2, 0)
44 #define STK8312_SR_400HZ_IDX 0
45 #define STK8312_ALL_CHANNEL_MASK GENMASK(2, 0)
46 #define STK8312_ALL_CHANNEL_SIZE 3
48 #define STK8312_DRIVER_NAME "stk8312"
49 #define STK8312_IRQ_NAME "stk8312_event"
52 * The accelerometer has two measurement ranges:
54 * -6g - +6g (8-bit, signed)
55 * -16g - +16g (8-bit, signed)
57 * scale1 = (6 + 6) * 9.81 / (2^8 - 1) = 0.4616
58 * scale2 = (16 + 16) * 9.81 / (2^8 - 1) = 1.2311
60 #define STK8312_SCALE_AVAIL "0.4616 1.2311"
62 static const int stk8312_scale_table
[][2] = {
63 {0, 461600}, {1, 231100}
69 } stk8312_samp_freq_table
[] = {
70 {400, 0}, {200, 0}, {100, 0}, {50, 0}, {25, 0},
71 {12, 500000}, {6, 250000}, {3, 125000}
74 #define STK8312_ACCEL_CHANNEL(index, reg, axis) { \
78 .channel2 = IIO_MOD_##axis, \
79 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
80 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
81 BIT(IIO_CHAN_INFO_SAMP_FREQ), \
82 .scan_index = index, \
87 .endianness = IIO_CPU, \
91 static const struct iio_chan_spec stk8312_channels
[] = {
92 STK8312_ACCEL_CHANNEL(0, STK8312_REG_XOUT
, X
),
93 STK8312_ACCEL_CHANNEL(1, STK8312_REG_YOUT
, Y
),
94 STK8312_ACCEL_CHANNEL(2, STK8312_REG_ZOUT
, Z
),
95 IIO_CHAN_SOFT_TIMESTAMP(3),
99 struct i2c_client
*client
;
104 struct iio_trigger
*dready_trig
;
105 bool dready_trigger_on
;
106 /* Ensure timestamp is naturally aligned */
109 aligned_s64 timestamp
;
113 static IIO_CONST_ATTR(in_accel_scale_available
, STK8312_SCALE_AVAIL
);
115 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400");
117 static struct attribute
*stk8312_attributes
[] = {
118 &iio_const_attr_in_accel_scale_available
.dev_attr
.attr
,
119 &iio_const_attr_sampling_frequency_available
.dev_attr
.attr
,
123 static const struct attribute_group stk8312_attribute_group
= {
124 .attrs
= stk8312_attributes
127 static int stk8312_otp_init(struct stk8312_data
*data
)
131 struct i2c_client
*client
= data
->client
;
133 ret
= i2c_smbus_write_byte_data(client
, STK8312_REG_OTPADDR
, 0x70);
136 ret
= i2c_smbus_write_byte_data(client
, STK8312_REG_OTPCTRL
, 0x02);
141 usleep_range(1000, 5000);
142 ret
= i2c_smbus_read_byte_data(client
, STK8312_REG_OTPCTRL
);
146 } while (!(ret
& BIT(7)) && count
> 0);
153 ret
= i2c_smbus_read_byte_data(client
, STK8312_REG_OTPDATA
);
159 ret
= i2c_smbus_write_byte_data(data
->client
, STK8312_REG_AFECTRL
, ret
);
167 dev_err(&client
->dev
, "failed to initialize sensor\n");
171 static int stk8312_set_mode(struct stk8312_data
*data
, u8 mode
)
174 struct i2c_client
*client
= data
->client
;
176 if (mode
== data
->mode
)
179 ret
= i2c_smbus_write_byte_data(client
, STK8312_REG_MODE
, mode
);
181 dev_err(&client
->dev
, "failed to change sensor mode\n");
186 if (mode
& STK8312_MODE_ACTIVE
) {
187 /* Need to run OTP sequence before entering active mode */
188 usleep_range(1000, 5000);
189 ret
= stk8312_otp_init(data
);
195 static int stk8312_set_interrupts(struct stk8312_data
*data
, u8 int_mask
)
199 struct i2c_client
*client
= data
->client
;
202 /* We need to go in standby mode to modify registers */
203 ret
= stk8312_set_mode(data
, STK8312_MODE_STANDBY
);
207 ret
= i2c_smbus_write_byte_data(client
, STK8312_REG_INTSU
, int_mask
);
209 dev_err(&client
->dev
, "failed to set interrupts\n");
210 stk8312_set_mode(data
, mode
);
214 return stk8312_set_mode(data
, mode
);
217 static int stk8312_data_rdy_trigger_set_state(struct iio_trigger
*trig
,
220 struct iio_dev
*indio_dev
= iio_trigger_get_drvdata(trig
);
221 struct stk8312_data
*data
= iio_priv(indio_dev
);
225 ret
= stk8312_set_interrupts(data
, STK8312_DREADY_BIT
);
227 ret
= stk8312_set_interrupts(data
, 0x00);
230 dev_err(&data
->client
->dev
, "failed to set trigger state\n");
234 data
->dready_trigger_on
= state
;
239 static const struct iio_trigger_ops stk8312_trigger_ops
= {
240 .set_trigger_state
= stk8312_data_rdy_trigger_set_state
,
243 static int stk8312_set_sample_rate(struct stk8312_data
*data
, u8 rate
)
248 struct i2c_client
*client
= data
->client
;
250 if (rate
== data
->sample_rate_idx
)
254 /* We need to go in standby mode to modify registers */
255 ret
= stk8312_set_mode(data
, STK8312_MODE_STANDBY
);
259 ret
= i2c_smbus_read_byte_data(client
, STK8312_REG_SR
);
263 masked_reg
= (ret
& (~STK8312_SR_MASK
)) | rate
;
265 ret
= i2c_smbus_write_byte_data(client
, STK8312_REG_SR
, masked_reg
);
269 data
->sample_rate_idx
= rate
;
271 return stk8312_set_mode(data
, mode
);
274 dev_err(&client
->dev
, "failed to set sampling rate\n");
275 stk8312_set_mode(data
, mode
);
280 static int stk8312_set_range(struct stk8312_data
*data
, u8 range
)
285 struct i2c_client
*client
= data
->client
;
287 if (range
!= 1 && range
!= 2)
289 else if (range
== data
->range
)
293 /* We need to go in standby mode to modify registers */
294 ret
= stk8312_set_mode(data
, STK8312_MODE_STANDBY
);
298 ret
= i2c_smbus_read_byte_data(client
, STK8312_REG_STH
);
302 masked_reg
= ret
& (~STK8312_RNG_MASK
);
303 masked_reg
|= range
<< STK8312_RNG_SHIFT
;
305 ret
= i2c_smbus_write_byte_data(client
, STK8312_REG_STH
, masked_reg
);
311 return stk8312_set_mode(data
, mode
);
314 dev_err(&client
->dev
, "failed to change sensor range\n");
315 stk8312_set_mode(data
, mode
);
320 static int stk8312_read_accel(struct stk8312_data
*data
, u8 address
)
323 struct i2c_client
*client
= data
->client
;
328 ret
= i2c_smbus_read_byte_data(client
, address
);
330 dev_err(&client
->dev
, "register read failed\n");
335 static int stk8312_read_raw(struct iio_dev
*indio_dev
,
336 struct iio_chan_spec
const *chan
,
337 int *val
, int *val2
, long mask
)
339 struct stk8312_data
*data
= iio_priv(indio_dev
);
343 case IIO_CHAN_INFO_RAW
:
344 if (iio_buffer_enabled(indio_dev
))
346 mutex_lock(&data
->lock
);
347 ret
= stk8312_set_mode(data
, data
->mode
| STK8312_MODE_ACTIVE
);
349 mutex_unlock(&data
->lock
);
352 ret
= stk8312_read_accel(data
, chan
->address
);
354 stk8312_set_mode(data
,
355 data
->mode
& (~STK8312_MODE_ACTIVE
));
356 mutex_unlock(&data
->lock
);
359 *val
= sign_extend32(ret
, chan
->scan_type
.realbits
- 1);
360 ret
= stk8312_set_mode(data
,
361 data
->mode
& (~STK8312_MODE_ACTIVE
));
362 mutex_unlock(&data
->lock
);
366 case IIO_CHAN_INFO_SCALE
:
367 *val
= stk8312_scale_table
[data
->range
- 1][0];
368 *val2
= stk8312_scale_table
[data
->range
- 1][1];
369 return IIO_VAL_INT_PLUS_MICRO
;
370 case IIO_CHAN_INFO_SAMP_FREQ
:
371 *val
= stk8312_samp_freq_table
[data
->sample_rate_idx
].val
;
372 *val2
= stk8312_samp_freq_table
[data
->sample_rate_idx
].val2
;
373 return IIO_VAL_INT_PLUS_MICRO
;
379 static int stk8312_write_raw(struct iio_dev
*indio_dev
,
380 struct iio_chan_spec
const *chan
,
381 int val
, int val2
, long mask
)
386 struct stk8312_data
*data
= iio_priv(indio_dev
);
389 case IIO_CHAN_INFO_SCALE
:
390 for (i
= 0; i
< ARRAY_SIZE(stk8312_scale_table
); i
++)
391 if (val
== stk8312_scale_table
[i
][0] &&
392 val2
== stk8312_scale_table
[i
][1]) {
399 mutex_lock(&data
->lock
);
400 ret
= stk8312_set_range(data
, index
);
401 mutex_unlock(&data
->lock
);
404 case IIO_CHAN_INFO_SAMP_FREQ
:
405 for (i
= 0; i
< ARRAY_SIZE(stk8312_samp_freq_table
); i
++)
406 if (val
== stk8312_samp_freq_table
[i
].val
&&
407 val2
== stk8312_samp_freq_table
[i
].val2
) {
413 mutex_lock(&data
->lock
);
414 ret
= stk8312_set_sample_rate(data
, index
);
415 mutex_unlock(&data
->lock
);
423 static const struct iio_info stk8312_info
= {
424 .read_raw
= stk8312_read_raw
,
425 .write_raw
= stk8312_write_raw
,
426 .attrs
= &stk8312_attribute_group
,
429 static irqreturn_t
stk8312_trigger_handler(int irq
, void *p
)
431 struct iio_poll_func
*pf
= p
;
432 struct iio_dev
*indio_dev
= pf
->indio_dev
;
433 struct stk8312_data
*data
= iio_priv(indio_dev
);
436 mutex_lock(&data
->lock
);
438 * Do a bulk read if all channels are requested,
439 * from 0x00 (XOUT) to 0x02 (ZOUT)
441 if (*(indio_dev
->active_scan_mask
) == STK8312_ALL_CHANNEL_MASK
) {
442 ret
= i2c_smbus_read_i2c_block_data(data
->client
,
444 STK8312_ALL_CHANNEL_SIZE
,
446 if (ret
< STK8312_ALL_CHANNEL_SIZE
) {
447 dev_err(&data
->client
->dev
, "register read failed\n");
448 mutex_unlock(&data
->lock
);
452 iio_for_each_active_channel(indio_dev
, bit
) {
453 ret
= stk8312_read_accel(data
, bit
);
455 mutex_unlock(&data
->lock
);
458 data
->scan
.chans
[i
++] = ret
;
461 mutex_unlock(&data
->lock
);
463 iio_push_to_buffers_with_timestamp(indio_dev
, &data
->scan
,
466 iio_trigger_notify_done(indio_dev
->trig
);
471 static irqreturn_t
stk8312_data_rdy_trig_poll(int irq
, void *private)
473 struct iio_dev
*indio_dev
= private;
474 struct stk8312_data
*data
= iio_priv(indio_dev
);
476 if (data
->dready_trigger_on
)
477 iio_trigger_poll(data
->dready_trig
);
482 static int stk8312_buffer_preenable(struct iio_dev
*indio_dev
)
484 struct stk8312_data
*data
= iio_priv(indio_dev
);
486 return stk8312_set_mode(data
, data
->mode
| STK8312_MODE_ACTIVE
);
489 static int stk8312_buffer_postdisable(struct iio_dev
*indio_dev
)
491 struct stk8312_data
*data
= iio_priv(indio_dev
);
493 return stk8312_set_mode(data
, data
->mode
& (~STK8312_MODE_ACTIVE
));
496 static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops
= {
497 .preenable
= stk8312_buffer_preenable
,
498 .postdisable
= stk8312_buffer_postdisable
,
501 static int stk8312_probe(struct i2c_client
*client
)
504 struct iio_dev
*indio_dev
;
505 struct stk8312_data
*data
;
507 indio_dev
= devm_iio_device_alloc(&client
->dev
, sizeof(*data
));
509 dev_err(&client
->dev
, "iio allocation failed!\n");
513 data
= iio_priv(indio_dev
);
514 data
->client
= client
;
515 i2c_set_clientdata(client
, indio_dev
);
516 mutex_init(&data
->lock
);
518 indio_dev
->info
= &stk8312_info
;
519 indio_dev
->name
= STK8312_DRIVER_NAME
;
520 indio_dev
->modes
= INDIO_DIRECT_MODE
;
521 indio_dev
->channels
= stk8312_channels
;
522 indio_dev
->num_channels
= ARRAY_SIZE(stk8312_channels
);
524 /* A software reset is recommended at power-on */
525 ret
= i2c_smbus_write_byte_data(data
->client
, STK8312_REG_RESET
, 0x00);
527 dev_err(&client
->dev
, "failed to reset sensor\n");
530 data
->sample_rate_idx
= STK8312_SR_400HZ_IDX
;
531 ret
= stk8312_set_range(data
, STK8312_RNG_6G
);
535 ret
= stk8312_set_mode(data
,
536 STK8312_MODE_INT_AH_PP
| STK8312_MODE_ACTIVE
);
540 if (client
->irq
> 0) {
541 ret
= devm_request_threaded_irq(&client
->dev
, client
->irq
,
542 stk8312_data_rdy_trig_poll
,
544 IRQF_TRIGGER_RISING
|
549 dev_err(&client
->dev
, "request irq %d failed\n",
554 data
->dready_trig
= devm_iio_trigger_alloc(&client
->dev
,
557 iio_device_id(indio_dev
));
558 if (!data
->dready_trig
) {
563 data
->dready_trig
->ops
= &stk8312_trigger_ops
;
564 iio_trigger_set_drvdata(data
->dready_trig
, indio_dev
);
565 ret
= iio_trigger_register(data
->dready_trig
);
567 dev_err(&client
->dev
, "iio trigger register failed\n");
572 ret
= iio_triggered_buffer_setup(indio_dev
,
573 iio_pollfunc_store_time
,
574 stk8312_trigger_handler
,
575 &stk8312_buffer_setup_ops
);
577 dev_err(&client
->dev
, "iio triggered buffer setup failed\n");
578 goto err_trigger_unregister
;
581 ret
= iio_device_register(indio_dev
);
583 dev_err(&client
->dev
, "device_register failed\n");
584 goto err_buffer_cleanup
;
590 iio_triggered_buffer_cleanup(indio_dev
);
591 err_trigger_unregister
:
592 if (data
->dready_trig
)
593 iio_trigger_unregister(data
->dready_trig
);
595 stk8312_set_mode(data
, STK8312_MODE_STANDBY
);
599 static void stk8312_remove(struct i2c_client
*client
)
601 struct iio_dev
*indio_dev
= i2c_get_clientdata(client
);
602 struct stk8312_data
*data
= iio_priv(indio_dev
);
604 iio_device_unregister(indio_dev
);
605 iio_triggered_buffer_cleanup(indio_dev
);
607 if (data
->dready_trig
)
608 iio_trigger_unregister(data
->dready_trig
);
610 stk8312_set_mode(data
, STK8312_MODE_STANDBY
);
613 static int stk8312_suspend(struct device
*dev
)
615 struct stk8312_data
*data
;
617 data
= iio_priv(i2c_get_clientdata(to_i2c_client(dev
)));
619 return stk8312_set_mode(data
, data
->mode
& (~STK8312_MODE_ACTIVE
));
622 static int stk8312_resume(struct device
*dev
)
624 struct stk8312_data
*data
;
626 data
= iio_priv(i2c_get_clientdata(to_i2c_client(dev
)));
628 return stk8312_set_mode(data
, data
->mode
| STK8312_MODE_ACTIVE
);
631 static DEFINE_SIMPLE_DEV_PM_OPS(stk8312_pm_ops
, stk8312_suspend
,
634 static const struct i2c_device_id stk8312_i2c_id
[] = {
635 /* Deprecated in favour of lowercase form */
640 MODULE_DEVICE_TABLE(i2c
, stk8312_i2c_id
);
642 static struct i2c_driver stk8312_driver
= {
644 .name
= STK8312_DRIVER_NAME
,
645 .pm
= pm_sleep_ptr(&stk8312_pm_ops
),
647 .probe
= stk8312_probe
,
648 .remove
= stk8312_remove
,
649 .id_table
= stk8312_i2c_id
,
652 module_i2c_driver(stk8312_driver
);
654 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
655 MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");
656 MODULE_LICENSE("GPL v2");