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/acpi.h>
11 #include <linux/i2c.h>
12 #include <linux/interrupt.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/delay.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 s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 64-bit timestamp */
109 static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);
111 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400");
113 static struct attribute *stk8312_attributes[] = {
114 &iio_const_attr_in_accel_scale_available.dev_attr.attr,
115 &iio_const_attr_sampling_frequency_available.dev_attr.attr,
119 static const struct attribute_group stk8312_attribute_group = {
120 .attrs = stk8312_attributes
123 static int stk8312_otp_init(struct stk8312_data *data)
127 struct i2c_client *client = data->client;
129 ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70);
132 ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02);
137 usleep_range(1000, 5000);
138 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL);
142 } while (!(ret & BIT(7)) && count > 0);
149 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA);
155 ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_AFECTRL, ret);
163 dev_err(&client->dev, "failed to initialize sensor\n");
167 static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
170 struct i2c_client *client = data->client;
172 if (mode == data->mode)
175 ret = i2c_smbus_write_byte_data(client, STK8312_REG_MODE, mode);
177 dev_err(&client->dev, "failed to change sensor mode\n");
182 if (mode & STK8312_MODE_ACTIVE) {
183 /* Need to run OTP sequence before entering active mode */
184 usleep_range(1000, 5000);
185 ret = stk8312_otp_init(data);
191 static int stk8312_set_interrupts(struct stk8312_data *data, u8 int_mask)
195 struct i2c_client *client = data->client;
198 /* We need to go in standby mode to modify registers */
199 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
203 ret = i2c_smbus_write_byte_data(client, STK8312_REG_INTSU, int_mask);
205 dev_err(&client->dev, "failed to set interrupts\n");
206 stk8312_set_mode(data, mode);
210 return stk8312_set_mode(data, mode);
213 static int stk8312_data_rdy_trigger_set_state(struct iio_trigger *trig,
216 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
217 struct stk8312_data *data = iio_priv(indio_dev);
221 ret = stk8312_set_interrupts(data, STK8312_DREADY_BIT);
223 ret = stk8312_set_interrupts(data, 0x00);
226 dev_err(&data->client->dev, "failed to set trigger state\n");
230 data->dready_trigger_on = state;
235 static const struct iio_trigger_ops stk8312_trigger_ops = {
236 .set_trigger_state = stk8312_data_rdy_trigger_set_state,
239 static int stk8312_set_sample_rate(struct stk8312_data *data, u8 rate)
244 struct i2c_client *client = data->client;
246 if (rate == data->sample_rate_idx)
250 /* We need to go in standby mode to modify registers */
251 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
255 ret = i2c_smbus_read_byte_data(client, STK8312_REG_SR);
259 masked_reg = (ret & (~STK8312_SR_MASK)) | rate;
261 ret = i2c_smbus_write_byte_data(client, STK8312_REG_SR, masked_reg);
265 data->sample_rate_idx = rate;
267 return stk8312_set_mode(data, mode);
270 dev_err(&client->dev, "failed to set sampling rate\n");
271 stk8312_set_mode(data, mode);
276 static int stk8312_set_range(struct stk8312_data *data, u8 range)
281 struct i2c_client *client = data->client;
283 if (range != 1 && range != 2)
285 else if (range == data->range)
289 /* We need to go in standby mode to modify registers */
290 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
294 ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH);
298 masked_reg = ret & (~STK8312_RNG_MASK);
299 masked_reg |= range << STK8312_RNG_SHIFT;
301 ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg);
307 return stk8312_set_mode(data, mode);
310 dev_err(&client->dev, "failed to change sensor range\n");
311 stk8312_set_mode(data, mode);
316 static int stk8312_read_accel(struct stk8312_data *data, u8 address)
319 struct i2c_client *client = data->client;
324 ret = i2c_smbus_read_byte_data(client, address);
326 dev_err(&client->dev, "register read failed\n");
331 static int stk8312_read_raw(struct iio_dev *indio_dev,
332 struct iio_chan_spec const *chan,
333 int *val, int *val2, long mask)
335 struct stk8312_data *data = iio_priv(indio_dev);
339 case IIO_CHAN_INFO_RAW:
340 if (iio_buffer_enabled(indio_dev))
342 mutex_lock(&data->lock);
343 ret = stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
345 mutex_unlock(&data->lock);
348 ret = stk8312_read_accel(data, chan->address);
350 stk8312_set_mode(data,
351 data->mode & (~STK8312_MODE_ACTIVE));
352 mutex_unlock(&data->lock);
355 *val = sign_extend32(ret, 7);
356 ret = stk8312_set_mode(data,
357 data->mode & (~STK8312_MODE_ACTIVE));
358 mutex_unlock(&data->lock);
362 case IIO_CHAN_INFO_SCALE:
363 *val = stk8312_scale_table[data->range - 1][0];
364 *val2 = stk8312_scale_table[data->range - 1][1];
365 return IIO_VAL_INT_PLUS_MICRO;
366 case IIO_CHAN_INFO_SAMP_FREQ:
367 *val = stk8312_samp_freq_table[data->sample_rate_idx].val;
368 *val2 = stk8312_samp_freq_table[data->sample_rate_idx].val2;
369 return IIO_VAL_INT_PLUS_MICRO;
375 static int stk8312_write_raw(struct iio_dev *indio_dev,
376 struct iio_chan_spec const *chan,
377 int val, int val2, long mask)
382 struct stk8312_data *data = iio_priv(indio_dev);
385 case IIO_CHAN_INFO_SCALE:
386 for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++)
387 if (val == stk8312_scale_table[i][0] &&
388 val2 == stk8312_scale_table[i][1]) {
395 mutex_lock(&data->lock);
396 ret = stk8312_set_range(data, index);
397 mutex_unlock(&data->lock);
400 case IIO_CHAN_INFO_SAMP_FREQ:
401 for (i = 0; i < ARRAY_SIZE(stk8312_samp_freq_table); i++)
402 if (val == stk8312_samp_freq_table[i].val &&
403 val2 == stk8312_samp_freq_table[i].val2) {
409 mutex_lock(&data->lock);
410 ret = stk8312_set_sample_rate(data, index);
411 mutex_unlock(&data->lock);
419 static const struct iio_info stk8312_info = {
420 .read_raw = stk8312_read_raw,
421 .write_raw = stk8312_write_raw,
422 .attrs = &stk8312_attribute_group,
425 static irqreturn_t stk8312_trigger_handler(int irq, void *p)
427 struct iio_poll_func *pf = p;
428 struct iio_dev *indio_dev = pf->indio_dev;
429 struct stk8312_data *data = iio_priv(indio_dev);
432 mutex_lock(&data->lock);
434 * Do a bulk read if all channels are requested,
435 * from 0x00 (XOUT) to 0x02 (ZOUT)
437 if (*(indio_dev->active_scan_mask) == STK8312_ALL_CHANNEL_MASK) {
438 ret = i2c_smbus_read_i2c_block_data(data->client,
440 STK8312_ALL_CHANNEL_SIZE,
442 if (ret < STK8312_ALL_CHANNEL_SIZE) {
443 dev_err(&data->client->dev, "register read failed\n");
444 mutex_unlock(&data->lock);
448 for_each_set_bit(bit, indio_dev->active_scan_mask,
449 indio_dev->masklength) {
450 ret = stk8312_read_accel(data, bit);
452 mutex_unlock(&data->lock);
455 data->buffer[i++] = ret;
458 mutex_unlock(&data->lock);
460 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
463 iio_trigger_notify_done(indio_dev->trig);
468 static irqreturn_t stk8312_data_rdy_trig_poll(int irq, void *private)
470 struct iio_dev *indio_dev = private;
471 struct stk8312_data *data = iio_priv(indio_dev);
473 if (data->dready_trigger_on)
474 iio_trigger_poll(data->dready_trig);
479 static int stk8312_buffer_preenable(struct iio_dev *indio_dev)
481 struct stk8312_data *data = iio_priv(indio_dev);
483 return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
486 static int stk8312_buffer_postdisable(struct iio_dev *indio_dev)
488 struct stk8312_data *data = iio_priv(indio_dev);
490 return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
493 static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops = {
494 .preenable = stk8312_buffer_preenable,
495 .postenable = iio_triggered_buffer_postenable,
496 .predisable = iio_triggered_buffer_predisable,
497 .postdisable = stk8312_buffer_postdisable,
500 static int stk8312_probe(struct i2c_client *client,
501 const struct i2c_device_id *id)
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->dev.parent = &client->dev;
519 indio_dev->info = &stk8312_info;
520 indio_dev->name = STK8312_DRIVER_NAME;
521 indio_dev->modes = INDIO_DIRECT_MODE;
522 indio_dev->channels = stk8312_channels;
523 indio_dev->num_channels = ARRAY_SIZE(stk8312_channels);
525 /* A software reset is recommended at power-on */
526 ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00);
528 dev_err(&client->dev, "failed to reset sensor\n");
531 data->sample_rate_idx = STK8312_SR_400HZ_IDX;
532 ret = stk8312_set_range(data, STK8312_RNG_6G);
536 ret = stk8312_set_mode(data,
537 STK8312_MODE_INT_AH_PP | STK8312_MODE_ACTIVE);
541 if (client->irq > 0) {
542 ret = devm_request_threaded_irq(&client->dev, client->irq,
543 stk8312_data_rdy_trig_poll,
545 IRQF_TRIGGER_RISING |
550 dev_err(&client->dev, "request irq %d failed\n",
555 data->dready_trig = devm_iio_trigger_alloc(&client->dev,
559 if (!data->dready_trig) {
564 data->dready_trig->dev.parent = &client->dev;
565 data->dready_trig->ops = &stk8312_trigger_ops;
566 iio_trigger_set_drvdata(data->dready_trig, indio_dev);
567 ret = iio_trigger_register(data->dready_trig);
569 dev_err(&client->dev, "iio trigger register failed\n");
574 ret = iio_triggered_buffer_setup(indio_dev,
575 iio_pollfunc_store_time,
576 stk8312_trigger_handler,
577 &stk8312_buffer_setup_ops);
579 dev_err(&client->dev, "iio triggered buffer setup failed\n");
580 goto err_trigger_unregister;
583 ret = iio_device_register(indio_dev);
585 dev_err(&client->dev, "device_register failed\n");
586 goto err_buffer_cleanup;
592 iio_triggered_buffer_cleanup(indio_dev);
593 err_trigger_unregister:
594 if (data->dready_trig)
595 iio_trigger_unregister(data->dready_trig);
597 stk8312_set_mode(data, STK8312_MODE_STANDBY);
601 static int stk8312_remove(struct i2c_client *client)
603 struct iio_dev *indio_dev = i2c_get_clientdata(client);
604 struct stk8312_data *data = iio_priv(indio_dev);
606 iio_device_unregister(indio_dev);
607 iio_triggered_buffer_cleanup(indio_dev);
609 if (data->dready_trig)
610 iio_trigger_unregister(data->dready_trig);
612 return stk8312_set_mode(data, STK8312_MODE_STANDBY);
615 #ifdef CONFIG_PM_SLEEP
616 static int stk8312_suspend(struct device *dev)
618 struct stk8312_data *data;
620 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
622 return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
625 static int stk8312_resume(struct device *dev)
627 struct stk8312_data *data;
629 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
631 return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
634 static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);
636 #define STK8312_PM_OPS (&stk8312_pm_ops)
638 #define STK8312_PM_OPS NULL
641 static const struct i2c_device_id stk8312_i2c_id[] = {
645 MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id);
647 static const struct acpi_device_id stk8312_acpi_id[] = {
652 MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id);
654 static struct i2c_driver stk8312_driver = {
656 .name = STK8312_DRIVER_NAME,
657 .pm = STK8312_PM_OPS,
658 .acpi_match_table = ACPI_PTR(stk8312_acpi_id),
660 .probe = stk8312_probe,
661 .remove = stk8312_remove,
662 .id_table = stk8312_i2c_id,
665 module_i2c_driver(stk8312_driver);
668 MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");
669 MODULE_LICENSE("GPL v2");