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 BIT(0)
41 #define STK8312_MODE_STANDBY 0x00
42 #define STK8312_MODE_INT_AH_PP 0xC0 /* active-high, push-pull */
43 #define STK8312_DREADY_BIT BIT(4)
44 #define STK8312_RNG_6G 1
45 #define STK8312_RNG_SHIFT 6
46 #define STK8312_RNG_MASK GENMASK(7, 6)
47 #define STK8312_SR_MASK GENMASK(2, 0)
48 #define STK8312_SR_400HZ_IDX 0
49 #define STK8312_ALL_CHANNEL_MASK GENMASK(2, 0)
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 & BIT(7)) && count > 0);
154 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA);
160 ret = i2c_smbus_write_byte_data(data->client,
161 STK8312_REG_AFECTRL, ret);
169 dev_err(&client->dev, "failed to initialize sensor\n");
173 static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
176 struct i2c_client *client = data->client;
178 if (mode == data->mode)
181 ret = i2c_smbus_write_byte_data(client, STK8312_REG_MODE, mode);
183 dev_err(&client->dev, "failed to change sensor mode\n");
188 if (mode & STK8312_MODE_ACTIVE) {
189 /* Need to run OTP sequence before entering active mode */
190 usleep_range(1000, 5000);
191 ret = stk8312_otp_init(data);
197 static int stk8312_set_interrupts(struct stk8312_data *data, u8 int_mask)
201 struct i2c_client *client = data->client;
204 /* We need to go in standby mode to modify registers */
205 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
209 ret = i2c_smbus_write_byte_data(client, STK8312_REG_INTSU, int_mask);
211 dev_err(&client->dev, "failed to set interrupts\n");
212 stk8312_set_mode(data, mode);
216 return stk8312_set_mode(data, mode);
219 static int stk8312_data_rdy_trigger_set_state(struct iio_trigger *trig,
222 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
223 struct stk8312_data *data = iio_priv(indio_dev);
227 ret = stk8312_set_interrupts(data, STK8312_DREADY_BIT);
229 ret = stk8312_set_interrupts(data, 0x00);
232 dev_err(&data->client->dev, "failed to set trigger state\n");
236 data->dready_trigger_on = state;
241 static const struct iio_trigger_ops stk8312_trigger_ops = {
242 .set_trigger_state = stk8312_data_rdy_trigger_set_state,
243 .owner = THIS_MODULE,
246 static int stk8312_set_sample_rate(struct stk8312_data *data, u8 rate)
251 struct i2c_client *client = data->client;
253 if (rate == data->sample_rate_idx)
257 /* We need to go in standby mode to modify registers */
258 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
262 ret = i2c_smbus_read_byte_data(client, STK8312_REG_SR);
266 masked_reg = (ret & (~STK8312_SR_MASK)) | rate;
268 ret = i2c_smbus_write_byte_data(client, STK8312_REG_SR, masked_reg);
272 data->sample_rate_idx = rate;
274 return stk8312_set_mode(data, mode);
277 dev_err(&client->dev, "failed to set sampling rate\n");
278 stk8312_set_mode(data, mode);
283 static int stk8312_set_range(struct stk8312_data *data, u8 range)
288 struct i2c_client *client = data->client;
290 if (range != 1 && range != 2)
292 else if (range == data->range)
296 /* We need to go in standby mode to modify registers */
297 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
301 ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH);
305 masked_reg = ret & (~STK8312_RNG_MASK);
306 masked_reg |= range << STK8312_RNG_SHIFT;
308 ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg);
314 return stk8312_set_mode(data, mode);
317 dev_err(&client->dev, "failed to change sensor range\n");
318 stk8312_set_mode(data, mode);
323 static int stk8312_read_accel(struct stk8312_data *data, u8 address)
326 struct i2c_client *client = data->client;
331 ret = i2c_smbus_read_byte_data(client, address);
333 dev_err(&client->dev, "register read failed\n");
338 static int stk8312_read_raw(struct iio_dev *indio_dev,
339 struct iio_chan_spec const *chan,
340 int *val, int *val2, long mask)
342 struct stk8312_data *data = iio_priv(indio_dev);
346 case IIO_CHAN_INFO_RAW:
347 if (iio_buffer_enabled(indio_dev))
349 mutex_lock(&data->lock);
350 ret = stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
352 mutex_unlock(&data->lock);
355 ret = stk8312_read_accel(data, chan->address);
357 stk8312_set_mode(data,
358 data->mode & (~STK8312_MODE_ACTIVE));
359 mutex_unlock(&data->lock);
362 *val = sign_extend32(ret, 7);
363 ret = stk8312_set_mode(data,
364 data->mode & (~STK8312_MODE_ACTIVE));
365 mutex_unlock(&data->lock);
369 case IIO_CHAN_INFO_SCALE:
370 *val = stk8312_scale_table[data->range - 1][0];
371 *val2 = stk8312_scale_table[data->range - 1][1];
372 return IIO_VAL_INT_PLUS_MICRO;
373 case IIO_CHAN_INFO_SAMP_FREQ:
374 *val = stk8312_samp_freq_table[data->sample_rate_idx].val;
375 *val2 = stk8312_samp_freq_table[data->sample_rate_idx].val2;
376 return IIO_VAL_INT_PLUS_MICRO;
382 static int stk8312_write_raw(struct iio_dev *indio_dev,
383 struct iio_chan_spec const *chan,
384 int val, int val2, long mask)
389 struct stk8312_data *data = iio_priv(indio_dev);
392 case IIO_CHAN_INFO_SCALE:
393 for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++)
394 if (val == stk8312_scale_table[i][0] &&
395 val2 == stk8312_scale_table[i][1]) {
402 mutex_lock(&data->lock);
403 ret = stk8312_set_range(data, index);
404 mutex_unlock(&data->lock);
407 case IIO_CHAN_INFO_SAMP_FREQ:
408 for (i = 0; i < ARRAY_SIZE(stk8312_samp_freq_table); i++)
409 if (val == stk8312_samp_freq_table[i].val &&
410 val2 == stk8312_samp_freq_table[i].val2) {
416 mutex_lock(&data->lock);
417 ret = stk8312_set_sample_rate(data, index);
418 mutex_unlock(&data->lock);
426 static const struct iio_info stk8312_info = {
427 .driver_module = THIS_MODULE,
428 .read_raw = stk8312_read_raw,
429 .write_raw = stk8312_write_raw,
430 .attrs = &stk8312_attribute_group,
433 static irqreturn_t stk8312_trigger_handler(int irq, void *p)
435 struct iio_poll_func *pf = p;
436 struct iio_dev *indio_dev = pf->indio_dev;
437 struct stk8312_data *data = iio_priv(indio_dev);
439 u8 buffer[STK8312_ALL_CHANNEL_SIZE];
441 mutex_lock(&data->lock);
443 * Do a bulk read if all channels are requested,
444 * from 0x00 (XOUT) to 0x02 (ZOUT)
446 if (*(indio_dev->active_scan_mask) == STK8312_ALL_CHANNEL_MASK) {
447 ret = i2c_smbus_read_i2c_block_data(data->client,
449 STK8312_ALL_CHANNEL_SIZE,
451 if (ret < STK8312_ALL_CHANNEL_SIZE) {
452 dev_err(&data->client->dev, "register read failed\n");
453 mutex_unlock(&data->lock);
456 data->buffer[0] = buffer[0];
457 data->buffer[1] = buffer[1];
458 data->buffer[2] = buffer[2];
460 for_each_set_bit(bit, indio_dev->active_scan_mask,
461 indio_dev->masklength) {
462 ret = stk8312_read_accel(data, bit);
464 mutex_unlock(&data->lock);
467 data->buffer[i++] = ret;
470 mutex_unlock(&data->lock);
472 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
475 iio_trigger_notify_done(indio_dev->trig);
480 static irqreturn_t stk8312_data_rdy_trig_poll(int irq, void *private)
482 struct iio_dev *indio_dev = private;
483 struct stk8312_data *data = iio_priv(indio_dev);
485 if (data->dready_trigger_on)
486 iio_trigger_poll(data->dready_trig);
491 static int stk8312_buffer_preenable(struct iio_dev *indio_dev)
493 struct stk8312_data *data = iio_priv(indio_dev);
495 return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
498 static int stk8312_buffer_postdisable(struct iio_dev *indio_dev)
500 struct stk8312_data *data = iio_priv(indio_dev);
502 return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
505 static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops = {
506 .preenable = stk8312_buffer_preenable,
507 .postenable = iio_triggered_buffer_postenable,
508 .predisable = iio_triggered_buffer_predisable,
509 .postdisable = stk8312_buffer_postdisable,
512 static int stk8312_gpio_probe(struct i2c_client *client)
515 struct gpio_desc *gpio;
523 /* data ready gpio interrupt pin */
524 gpio = devm_gpiod_get_index(dev, STK8312_GPIO, 0, GPIOD_IN);
526 dev_err(dev, "acpi gpio get index failed\n");
527 return PTR_ERR(gpio);
530 ret = gpiod_to_irq(gpio);
531 dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio), ret);
536 static int stk8312_probe(struct i2c_client *client,
537 const struct i2c_device_id *id)
540 struct iio_dev *indio_dev;
541 struct stk8312_data *data;
543 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
545 dev_err(&client->dev, "iio allocation failed!\n");
549 data = iio_priv(indio_dev);
550 data->client = client;
551 i2c_set_clientdata(client, indio_dev);
552 mutex_init(&data->lock);
554 indio_dev->dev.parent = &client->dev;
555 indio_dev->info = &stk8312_info;
556 indio_dev->name = STK8312_DRIVER_NAME;
557 indio_dev->modes = INDIO_DIRECT_MODE;
558 indio_dev->channels = stk8312_channels;
559 indio_dev->num_channels = ARRAY_SIZE(stk8312_channels);
561 /* A software reset is recommended at power-on */
562 ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00);
564 dev_err(&client->dev, "failed to reset sensor\n");
567 data->sample_rate_idx = STK8312_SR_400HZ_IDX;
568 ret = stk8312_set_range(data, STK8312_RNG_6G);
572 ret = stk8312_set_mode(data,
573 STK8312_MODE_INT_AH_PP | STK8312_MODE_ACTIVE);
578 client->irq = stk8312_gpio_probe(client);
580 if (client->irq >= 0) {
581 ret = devm_request_threaded_irq(&client->dev, client->irq,
582 stk8312_data_rdy_trig_poll,
584 IRQF_TRIGGER_RISING |
589 dev_err(&client->dev, "request irq %d failed\n",
594 data->dready_trig = devm_iio_trigger_alloc(&client->dev,
598 if (!data->dready_trig) {
603 data->dready_trig->dev.parent = &client->dev;
604 data->dready_trig->ops = &stk8312_trigger_ops;
605 iio_trigger_set_drvdata(data->dready_trig, indio_dev);
606 ret = iio_trigger_register(data->dready_trig);
608 dev_err(&client->dev, "iio trigger register failed\n");
613 ret = iio_triggered_buffer_setup(indio_dev,
614 iio_pollfunc_store_time,
615 stk8312_trigger_handler,
616 &stk8312_buffer_setup_ops);
618 dev_err(&client->dev, "iio triggered buffer setup failed\n");
619 goto err_trigger_unregister;
622 ret = iio_device_register(indio_dev);
624 dev_err(&client->dev, "device_register failed\n");
625 goto err_buffer_cleanup;
631 iio_triggered_buffer_cleanup(indio_dev);
632 err_trigger_unregister:
633 if (data->dready_trig)
634 iio_trigger_unregister(data->dready_trig);
636 stk8312_set_mode(data, STK8312_MODE_STANDBY);
640 static int stk8312_remove(struct i2c_client *client)
642 struct iio_dev *indio_dev = i2c_get_clientdata(client);
643 struct stk8312_data *data = iio_priv(indio_dev);
645 iio_device_unregister(indio_dev);
646 iio_triggered_buffer_cleanup(indio_dev);
648 if (data->dready_trig)
649 iio_trigger_unregister(data->dready_trig);
651 return stk8312_set_mode(data, STK8312_MODE_STANDBY);
654 #ifdef CONFIG_PM_SLEEP
655 static int stk8312_suspend(struct device *dev)
657 struct stk8312_data *data;
659 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
661 return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
664 static int stk8312_resume(struct device *dev)
666 struct stk8312_data *data;
668 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
670 return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
673 static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);
675 #define STK8312_PM_OPS (&stk8312_pm_ops)
677 #define STK8312_PM_OPS NULL
680 static const struct i2c_device_id stk8312_i2c_id[] = {
684 MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id);
686 static const struct acpi_device_id stk8312_acpi_id[] = {
691 MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id);
693 static struct i2c_driver stk8312_driver = {
695 .name = STK8312_DRIVER_NAME,
696 .pm = STK8312_PM_OPS,
697 .acpi_match_table = ACPI_PTR(stk8312_acpi_id),
699 .probe = stk8312_probe,
700 .remove = stk8312_remove,
701 .id_table = stk8312_i2c_id,
704 module_i2c_driver(stk8312_driver);
706 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
707 MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");
708 MODULE_LICENSE("GPL v2");