2 * Sensortek STK8312 3-Axis Accelerometer
4 * Copyright (c) 2015, Intel Corporation.
6 * This file is subject to the terms and conditions of version 2 of
7 * the GNU General Public License. See the file COPYING in the main
8 * directory of this archive for more details.
10 * IIO driver for STK8312; 7-bit I2C address: 0x3D.
13 #include <linux/acpi.h>
14 #include <linux/gpio/consumer.h>
15 #include <linux/i2c.h>
16 #include <linux/interrupt.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/delay.h>
20 #include <linux/iio/buffer.h>
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 #include <linux/iio/trigger.h>
24 #include <linux/iio/triggered_buffer.h>
25 #include <linux/iio/trigger_consumer.h>
27 #define STK8312_REG_XOUT 0x00
28 #define STK8312_REG_YOUT 0x01
29 #define STK8312_REG_ZOUT 0x02
30 #define STK8312_REG_INTSU 0x06
31 #define STK8312_REG_MODE 0x07
32 #define STK8312_REG_SR 0x08
33 #define STK8312_REG_STH 0x13
34 #define STK8312_REG_RESET 0x20
35 #define STK8312_REG_AFECTRL 0x24
36 #define STK8312_REG_OTPADDR 0x3D
37 #define STK8312_REG_OTPDATA 0x3E
38 #define STK8312_REG_OTPCTRL 0x3F
40 #define STK8312_MODE_ACTIVE 0x01
41 #define STK8312_MODE_STANDBY 0x00
42 #define STK8312_DREADY_BIT 0x10
43 #define STK8312_INT_MODE 0xC0
44 #define STK8312_RNG_MASK 0xC0
45 #define STK8312_SR_MASK 0x07
46 #define STK8312_SR_400HZ_IDX 0
47 #define STK8312_RNG_SHIFT 6
48 #define STK8312_READ_RETRIES 16
49 #define STK8312_ALL_CHANNEL_MASK 7
50 #define STK8312_ALL_CHANNEL_SIZE 3
52 #define STK8312_DRIVER_NAME "stk8312"
53 #define STK8312_GPIO "stk8312_gpio"
54 #define STK8312_IRQ_NAME "stk8312_event"
57 * The accelerometer has two measurement ranges:
59 * -6g - +6g (8-bit, signed)
60 * -16g - +16g (8-bit, signed)
62 * scale1 = (6 + 6) * 9.81 / (2^8 - 1) = 0.4616
63 * scale2 = (16 + 16) * 9.81 / (2^8 - 1) = 1.2311
65 #define STK8312_SCALE_AVAIL "0.4616 1.2311"
67 static const int stk8312_scale_table[][2] = {
68 {0, 461600}, {1, 231100}
74 } stk8312_samp_freq_table[] = {
75 {400, 0}, {200, 0}, {100, 0}, {50, 0}, {25, 0},
76 {12, 500000}, {6, 250000}, {3, 125000}
79 #define STK8312_ACCEL_CHANNEL(index, reg, axis) { \
83 .channel2 = IIO_MOD_##axis, \
84 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
85 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
86 BIT(IIO_CHAN_INFO_SAMP_FREQ), \
87 .scan_index = index, \
92 .endianness = IIO_CPU, \
96 static const struct iio_chan_spec stk8312_channels[] = {
97 STK8312_ACCEL_CHANNEL(0, STK8312_REG_XOUT, X),
98 STK8312_ACCEL_CHANNEL(1, STK8312_REG_YOUT, Y),
99 STK8312_ACCEL_CHANNEL(2, STK8312_REG_ZOUT, Z),
100 IIO_CHAN_SOFT_TIMESTAMP(3),
103 struct stk8312_data {
104 struct i2c_client *client;
109 struct iio_trigger *dready_trig;
110 bool dready_trigger_on;
111 s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 64-bit timestamp */
114 static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);
116 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400");
118 static struct attribute *stk8312_attributes[] = {
119 &iio_const_attr_in_accel_scale_available.dev_attr.attr,
120 &iio_const_attr_sampling_frequency_available.dev_attr.attr,
124 static const struct attribute_group stk8312_attribute_group = {
125 .attrs = stk8312_attributes
128 static int stk8312_otp_init(struct stk8312_data *data)
132 struct i2c_client *client = data->client;
134 ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70);
137 ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02);
142 usleep_range(1000, 5000);
143 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL);
147 } while (!(ret & 0x80) && count > 0);
152 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA);
156 ret = i2c_smbus_write_byte_data(data->client,
157 STK8312_REG_AFECTRL, ret);
165 dev_err(&client->dev, "failed to initialize sensor\n");
169 static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
172 struct i2c_client *client = data->client;
174 if (mode == data->mode)
177 ret = i2c_smbus_write_byte_data(client, STK8312_REG_MODE, mode);
179 dev_err(&client->dev, "failed to change sensor mode\n");
184 if (mode & STK8312_MODE_ACTIVE) {
185 /* Need to run OTP sequence before entering active mode */
186 usleep_range(1000, 5000);
187 ret = stk8312_otp_init(data);
193 static int stk8312_set_interrupts(struct stk8312_data *data, u8 int_mask)
197 struct i2c_client *client = data->client;
200 /* We need to go in standby mode to modify registers */
201 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
205 ret = i2c_smbus_write_byte_data(client, STK8312_REG_INTSU, int_mask);
207 dev_err(&client->dev, "failed to set interrupts\n");
209 return stk8312_set_mode(data, mode);
212 static int stk8312_data_rdy_trigger_set_state(struct iio_trigger *trig,
215 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
216 struct stk8312_data *data = iio_priv(indio_dev);
220 ret = stk8312_set_interrupts(data, STK8312_DREADY_BIT);
222 ret = stk8312_set_interrupts(data, 0x00);
225 dev_err(&data->client->dev, "failed to set trigger state\n");
229 data->dready_trigger_on = state;
234 static const struct iio_trigger_ops stk8312_trigger_ops = {
235 .set_trigger_state = stk8312_data_rdy_trigger_set_state,
236 .owner = THIS_MODULE,
239 static int stk8312_set_sample_rate(struct stk8312_data *data, int 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);
257 dev_err(&client->dev, "failed to set sampling rate\n");
261 masked_reg = (ret & (~STK8312_SR_MASK)) | rate;
263 ret = i2c_smbus_write_byte_data(client, STK8312_REG_SR, masked_reg);
265 dev_err(&client->dev, "failed to set sampling rate\n");
267 data->sample_rate_idx = rate;
269 return stk8312_set_mode(data, mode);
272 static int stk8312_set_range(struct stk8312_data *data, u8 range)
277 struct i2c_client *client = data->client;
279 if (range != 1 && range != 2)
281 else if (range == data->range)
285 /* We need to go in standby mode to modify registers */
286 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
290 ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH);
292 dev_err(&client->dev, "failed to change sensor range\n");
296 masked_reg = ret & (~STK8312_RNG_MASK);
297 masked_reg |= range << STK8312_RNG_SHIFT;
299 ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg);
301 dev_err(&client->dev, "failed to change sensor range\n");
305 return stk8312_set_mode(data, mode);
308 static int stk8312_read_accel(struct stk8312_data *data, u8 address)
311 struct i2c_client *client = data->client;
316 ret = i2c_smbus_read_byte_data(client, address);
318 dev_err(&client->dev, "register read failed\n");
323 static int stk8312_read_raw(struct iio_dev *indio_dev,
324 struct iio_chan_spec const *chan,
325 int *val, int *val2, long mask)
327 struct stk8312_data *data = iio_priv(indio_dev);
331 case IIO_CHAN_INFO_RAW:
332 if (iio_buffer_enabled(indio_dev))
334 mutex_lock(&data->lock);
335 ret = stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
337 mutex_unlock(&data->lock);
340 ret = stk8312_read_accel(data, chan->address);
342 stk8312_set_mode(data,
343 data->mode & (~STK8312_MODE_ACTIVE));
344 mutex_unlock(&data->lock);
347 *val = sign_extend32(ret, 7);
348 stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
349 mutex_unlock(&data->lock);
351 case IIO_CHAN_INFO_SCALE:
352 *val = stk8312_scale_table[data->range - 1][0];
353 *val2 = stk8312_scale_table[data->range - 1][1];
354 return IIO_VAL_INT_PLUS_MICRO;
355 case IIO_CHAN_INFO_SAMP_FREQ:
356 *val = stk8312_samp_freq_table[data->sample_rate_idx].val;
357 *val2 = stk8312_samp_freq_table[data->sample_rate_idx].val2;
358 return IIO_VAL_INT_PLUS_MICRO;
364 static int stk8312_write_raw(struct iio_dev *indio_dev,
365 struct iio_chan_spec const *chan,
366 int val, int val2, long mask)
371 struct stk8312_data *data = iio_priv(indio_dev);
374 case IIO_CHAN_INFO_SCALE:
375 for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++)
376 if (val == stk8312_scale_table[i][0] &&
377 val2 == stk8312_scale_table[i][1]) {
384 mutex_lock(&data->lock);
385 ret = stk8312_set_range(data, index);
386 mutex_unlock(&data->lock);
389 case IIO_CHAN_INFO_SAMP_FREQ:
390 for (i = 0; i < ARRAY_SIZE(stk8312_samp_freq_table); i++)
391 if (val == stk8312_samp_freq_table[i].val &&
392 val2 == stk8312_samp_freq_table[i].val2) {
398 mutex_lock(&data->lock);
399 ret = stk8312_set_sample_rate(data, index);
400 mutex_unlock(&data->lock);
408 static const struct iio_info stk8312_info = {
409 .driver_module = THIS_MODULE,
410 .read_raw = stk8312_read_raw,
411 .write_raw = stk8312_write_raw,
412 .attrs = &stk8312_attribute_group,
415 static irqreturn_t stk8312_trigger_handler(int irq, void *p)
417 struct iio_poll_func *pf = p;
418 struct iio_dev *indio_dev = pf->indio_dev;
419 struct stk8312_data *data = iio_priv(indio_dev);
421 u8 buffer[STK8312_ALL_CHANNEL_SIZE];
423 mutex_lock(&data->lock);
425 * Do a bulk read if all channels are requested,
426 * from 0x00 (XOUT) to 0x02 (ZOUT)
428 if (*(indio_dev->active_scan_mask) == STK8312_ALL_CHANNEL_MASK) {
429 ret = i2c_smbus_read_i2c_block_data(data->client,
431 STK8312_ALL_CHANNEL_SIZE,
433 if (ret < STK8312_ALL_CHANNEL_SIZE) {
434 dev_err(&data->client->dev, "register read failed\n");
435 mutex_unlock(&data->lock);
438 data->buffer[0] = buffer[0];
439 data->buffer[1] = buffer[1];
440 data->buffer[2] = buffer[2];
442 for_each_set_bit(bit, indio_dev->active_scan_mask,
443 indio_dev->masklength) {
444 ret = stk8312_read_accel(data, bit);
446 mutex_unlock(&data->lock);
449 data->buffer[i++] = ret;
452 mutex_unlock(&data->lock);
454 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
457 iio_trigger_notify_done(indio_dev->trig);
462 static irqreturn_t stk8312_data_rdy_trig_poll(int irq, void *private)
464 struct iio_dev *indio_dev = private;
465 struct stk8312_data *data = iio_priv(indio_dev);
467 if (data->dready_trigger_on)
468 iio_trigger_poll(data->dready_trig);
473 static int stk8312_buffer_preenable(struct iio_dev *indio_dev)
475 struct stk8312_data *data = iio_priv(indio_dev);
477 return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
480 static int stk8312_buffer_postdisable(struct iio_dev *indio_dev)
482 struct stk8312_data *data = iio_priv(indio_dev);
484 return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
487 static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops = {
488 .preenable = stk8312_buffer_preenable,
489 .postenable = iio_triggered_buffer_postenable,
490 .predisable = iio_triggered_buffer_predisable,
491 .postdisable = stk8312_buffer_postdisable,
494 static int stk8312_gpio_probe(struct i2c_client *client)
497 struct gpio_desc *gpio;
505 /* data ready gpio interrupt pin */
506 gpio = devm_gpiod_get_index(dev, STK8312_GPIO, 0, GPIOD_IN);
508 dev_err(dev, "acpi gpio get index failed\n");
509 return PTR_ERR(gpio);
512 ret = gpiod_to_irq(gpio);
513 dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio), ret);
518 static int stk8312_probe(struct i2c_client *client,
519 const struct i2c_device_id *id)
522 struct iio_dev *indio_dev;
523 struct stk8312_data *data;
525 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
527 dev_err(&client->dev, "iio allocation failed!\n");
531 data = iio_priv(indio_dev);
532 data->client = client;
533 i2c_set_clientdata(client, indio_dev);
534 mutex_init(&data->lock);
536 indio_dev->dev.parent = &client->dev;
537 indio_dev->info = &stk8312_info;
538 indio_dev->name = STK8312_DRIVER_NAME;
539 indio_dev->modes = INDIO_DIRECT_MODE;
540 indio_dev->channels = stk8312_channels;
541 indio_dev->num_channels = ARRAY_SIZE(stk8312_channels);
543 /* A software reset is recommended at power-on */
544 ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00);
546 dev_err(&client->dev, "failed to reset sensor\n");
549 data->sample_rate_idx = STK8312_SR_400HZ_IDX;
550 ret = stk8312_set_range(data, 1);
554 ret = stk8312_set_mode(data, STK8312_INT_MODE | STK8312_MODE_ACTIVE);
559 client->irq = stk8312_gpio_probe(client);
561 if (client->irq >= 0) {
562 ret = devm_request_threaded_irq(&client->dev, client->irq,
563 stk8312_data_rdy_trig_poll,
565 IRQF_TRIGGER_RISING |
570 dev_err(&client->dev, "request irq %d failed\n",
575 data->dready_trig = devm_iio_trigger_alloc(&client->dev,
579 if (!data->dready_trig) {
584 data->dready_trig->dev.parent = &client->dev;
585 data->dready_trig->ops = &stk8312_trigger_ops;
586 iio_trigger_set_drvdata(data->dready_trig, indio_dev);
587 ret = iio_trigger_register(data->dready_trig);
589 dev_err(&client->dev, "iio trigger register failed\n");
594 ret = iio_triggered_buffer_setup(indio_dev,
595 iio_pollfunc_store_time,
596 stk8312_trigger_handler,
597 &stk8312_buffer_setup_ops);
599 dev_err(&client->dev, "iio triggered buffer setup failed\n");
600 goto err_trigger_unregister;
603 ret = iio_device_register(indio_dev);
605 dev_err(&client->dev, "device_register failed\n");
606 goto err_buffer_cleanup;
612 iio_triggered_buffer_cleanup(indio_dev);
613 err_trigger_unregister:
614 if (data->dready_trig)
615 iio_trigger_unregister(data->dready_trig);
617 stk8312_set_mode(data, STK8312_MODE_STANDBY);
621 static int stk8312_remove(struct i2c_client *client)
623 struct iio_dev *indio_dev = i2c_get_clientdata(client);
624 struct stk8312_data *data = iio_priv(indio_dev);
626 iio_device_unregister(indio_dev);
627 iio_triggered_buffer_cleanup(indio_dev);
629 if (data->dready_trig)
630 iio_trigger_unregister(data->dready_trig);
632 return stk8312_set_mode(data, STK8312_MODE_STANDBY);
635 #ifdef CONFIG_PM_SLEEP
636 static int stk8312_suspend(struct device *dev)
638 struct stk8312_data *data;
640 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
642 return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
645 static int stk8312_resume(struct device *dev)
647 struct stk8312_data *data;
649 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
651 return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
654 static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);
656 #define STK8312_PM_OPS (&stk8312_pm_ops)
658 #define STK8312_PM_OPS NULL
661 static const struct i2c_device_id stk8312_i2c_id[] = {
665 MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id);
667 static const struct acpi_device_id stk8312_acpi_id[] = {
672 MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id);
674 static struct i2c_driver stk8312_driver = {
677 .pm = STK8312_PM_OPS,
678 .acpi_match_table = ACPI_PTR(stk8312_acpi_id),
680 .probe = stk8312_probe,
681 .remove = stk8312_remove,
682 .id_table = stk8312_i2c_id,
685 module_i2c_driver(stk8312_driver);
687 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
688 MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");
689 MODULE_LICENSE("GPL v2");