2 * Sensortek STK8BA50 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 * STK8BA50 7-bit I2C address: 0x18.
13 #include <linux/acpi.h>
14 #include <linux/i2c.h>
15 #include <linux/interrupt.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/iio/buffer.h>
19 #include <linux/iio/iio.h>
20 #include <linux/iio/sysfs.h>
21 #include <linux/iio/trigger.h>
22 #include <linux/iio/triggered_buffer.h>
23 #include <linux/iio/trigger_consumer.h>
25 #define STK8BA50_REG_XOUT 0x02
26 #define STK8BA50_REG_YOUT 0x04
27 #define STK8BA50_REG_ZOUT 0x06
28 #define STK8BA50_REG_RANGE 0x0F
29 #define STK8BA50_REG_BWSEL 0x10
30 #define STK8BA50_REG_POWMODE 0x11
31 #define STK8BA50_REG_SWRST 0x14
32 #define STK8BA50_REG_INTEN2 0x17
33 #define STK8BA50_REG_INTMAP2 0x1A
35 #define STK8BA50_MODE_NORMAL 0
36 #define STK8BA50_MODE_SUSPEND 1
37 #define STK8BA50_MODE_POWERBIT BIT(7)
38 #define STK8BA50_DATA_SHIFT 6
39 #define STK8BA50_RESET_CMD 0xB6
40 #define STK8BA50_SR_1792HZ_IDX 7
41 #define STK8BA50_DREADY_INT_MASK 0x10
42 #define STK8BA50_DREADY_INT_MAP 0x81
43 #define STK8BA50_ALL_CHANNEL_MASK 7
44 #define STK8BA50_ALL_CHANNEL_SIZE 6
46 #define STK8BA50_DRIVER_NAME "stk8ba50"
47 #define STK8BA50_IRQ_NAME "stk8ba50_event"
49 #define STK8BA50_SCALE_AVAIL "0.0384 0.0767 0.1534 0.3069"
52 * The accelerometer has four measurement ranges:
53 * +/-2g; +/-4g; +/-8g; +/-16g
55 * Acceleration values are 10-bit, 2's complement.
56 * Scales are calculated as following:
58 * scale1 = (2 + 2) * 9.81 / (2^10 - 1) = 0.0384
59 * scale2 = (4 + 4) * 9.81 / (2^10 - 1) = 0.0767
62 * Scales are stored in this format:
63 * { <register value>, <scale value> }
65 * Locally, the range is stored as a table index.
70 } stk8ba50_scale_table[] = {
71 {3, 38400}, {5, 76700}, {8, 153400}, {12, 306900}
74 /* Sample rates are stored as { <register value>, <Hz value> } */
78 } stk8ba50_samp_freq_table[] = {
79 {0x08, 14}, {0x09, 25}, {0x0A, 56}, {0x0B, 112},
80 {0x0C, 224}, {0x0D, 448}, {0x0E, 896}, {0x0F, 1792}
83 /* Used to map scan mask bits to their corresponding channel register. */
84 static const int stk8ba50_channel_table[] = {
90 struct stk8ba50_data {
91 struct i2c_client *client;
95 struct iio_trigger *dready_trig;
96 bool dready_trigger_on;
98 * 3 x 16-bit channels (10-bit data, 6-bit padding) +
100 * 4 x 16 64-bit timestamp
105 #define STK8BA50_ACCEL_CHANNEL(index, reg, axis) { \
109 .channel2 = IIO_MOD_##axis, \
110 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
111 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
112 BIT(IIO_CHAN_INFO_SAMP_FREQ), \
113 .scan_index = index, \
118 .shift = STK8BA50_DATA_SHIFT, \
119 .endianness = IIO_CPU, \
123 static const struct iio_chan_spec stk8ba50_channels[] = {
124 STK8BA50_ACCEL_CHANNEL(0, STK8BA50_REG_XOUT, X),
125 STK8BA50_ACCEL_CHANNEL(1, STK8BA50_REG_YOUT, Y),
126 STK8BA50_ACCEL_CHANNEL(2, STK8BA50_REG_ZOUT, Z),
127 IIO_CHAN_SOFT_TIMESTAMP(3),
130 static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL);
132 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("14 25 56 112 224 448 896 1792");
134 static struct attribute *stk8ba50_attributes[] = {
135 &iio_const_attr_in_accel_scale_available.dev_attr.attr,
136 &iio_const_attr_sampling_frequency_available.dev_attr.attr,
140 static const struct attribute_group stk8ba50_attribute_group = {
141 .attrs = stk8ba50_attributes
144 static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg)
147 struct i2c_client *client = data->client;
149 ret = i2c_smbus_read_word_data(client, reg);
151 dev_err(&client->dev, "register read failed\n");
158 static int stk8ba50_data_rdy_trigger_set_state(struct iio_trigger *trig,
161 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
162 struct stk8ba50_data *data = iio_priv(indio_dev);
166 ret = i2c_smbus_write_byte_data(data->client,
167 STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
169 ret = i2c_smbus_write_byte_data(data->client,
170 STK8BA50_REG_INTEN2, 0x00);
173 dev_err(&data->client->dev, "failed to set trigger state\n");
175 data->dready_trigger_on = state;
180 static const struct iio_trigger_ops stk8ba50_trigger_ops = {
181 .set_trigger_state = stk8ba50_data_rdy_trigger_set_state,
182 .owner = THIS_MODULE,
185 static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode)
189 struct i2c_client *client = data->client;
191 ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE);
196 masked_reg = ret | STK8BA50_MODE_POWERBIT;
198 masked_reg = ret & (~STK8BA50_MODE_POWERBIT);
200 ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE,
208 dev_err(&client->dev, "failed to change sensor mode\n");
212 static int stk8ba50_read_raw(struct iio_dev *indio_dev,
213 struct iio_chan_spec const *chan,
214 int *val, int *val2, long mask)
216 struct stk8ba50_data *data = iio_priv(indio_dev);
220 case IIO_CHAN_INFO_RAW:
221 if (iio_buffer_enabled(indio_dev))
223 mutex_lock(&data->lock);
224 ret = stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
226 mutex_unlock(&data->lock);
229 ret = stk8ba50_read_accel(data, chan->address);
231 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
232 mutex_unlock(&data->lock);
235 *val = sign_extend32(ret >> STK8BA50_DATA_SHIFT, 9);
236 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
237 mutex_unlock(&data->lock);
239 case IIO_CHAN_INFO_SCALE:
241 *val2 = stk8ba50_scale_table[data->range].scale_val;
242 return IIO_VAL_INT_PLUS_MICRO;
243 case IIO_CHAN_INFO_SAMP_FREQ:
244 *val = stk8ba50_samp_freq_table
245 [data->sample_rate_idx].samp_freq;
253 static int stk8ba50_write_raw(struct iio_dev *indio_dev,
254 struct iio_chan_spec const *chan,
255 int val, int val2, long mask)
260 struct stk8ba50_data *data = iio_priv(indio_dev);
263 case IIO_CHAN_INFO_SCALE:
267 for (i = 0; i < ARRAY_SIZE(stk8ba50_scale_table); i++)
268 if (val2 == stk8ba50_scale_table[i].scale_val) {
275 ret = i2c_smbus_write_byte_data(data->client,
277 stk8ba50_scale_table[index].reg_val);
279 dev_err(&data->client->dev,
280 "failed to set measurement range\n");
285 case IIO_CHAN_INFO_SAMP_FREQ:
286 for (i = 0; i < ARRAY_SIZE(stk8ba50_samp_freq_table); i++)
287 if (val == stk8ba50_samp_freq_table[i].samp_freq) {
294 ret = i2c_smbus_write_byte_data(data->client,
296 stk8ba50_samp_freq_table[index].reg_val);
298 dev_err(&data->client->dev,
299 "failed to set sampling rate\n");
301 data->sample_rate_idx = index;
309 static const struct iio_info stk8ba50_info = {
310 .driver_module = THIS_MODULE,
311 .read_raw = stk8ba50_read_raw,
312 .write_raw = stk8ba50_write_raw,
313 .attrs = &stk8ba50_attribute_group,
316 static irqreturn_t stk8ba50_trigger_handler(int irq, void *p)
318 struct iio_poll_func *pf = p;
319 struct iio_dev *indio_dev = pf->indio_dev;
320 struct stk8ba50_data *data = iio_priv(indio_dev);
323 mutex_lock(&data->lock);
325 * Do a bulk read if all channels are requested,
326 * from 0x02 (XOUT1) to 0x07 (ZOUT2)
328 if (*(indio_dev->active_scan_mask) == STK8BA50_ALL_CHANNEL_MASK) {
329 ret = i2c_smbus_read_i2c_block_data(data->client,
331 STK8BA50_ALL_CHANNEL_SIZE,
333 if (ret < STK8BA50_ALL_CHANNEL_SIZE) {
334 dev_err(&data->client->dev, "register read failed\n");
338 for_each_set_bit(bit, indio_dev->active_scan_mask,
339 indio_dev->masklength) {
340 ret = stk8ba50_read_accel(data,
341 stk8ba50_channel_table[bit]);
345 data->buffer[i++] = ret;
348 iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
351 mutex_unlock(&data->lock);
352 iio_trigger_notify_done(indio_dev->trig);
357 static irqreturn_t stk8ba50_data_rdy_trig_poll(int irq, void *private)
359 struct iio_dev *indio_dev = private;
360 struct stk8ba50_data *data = iio_priv(indio_dev);
362 if (data->dready_trigger_on)
363 iio_trigger_poll(data->dready_trig);
368 static int stk8ba50_buffer_preenable(struct iio_dev *indio_dev)
370 struct stk8ba50_data *data = iio_priv(indio_dev);
372 return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
375 static int stk8ba50_buffer_postdisable(struct iio_dev *indio_dev)
377 struct stk8ba50_data *data = iio_priv(indio_dev);
379 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
382 static const struct iio_buffer_setup_ops stk8ba50_buffer_setup_ops = {
383 .preenable = stk8ba50_buffer_preenable,
384 .postenable = iio_triggered_buffer_postenable,
385 .predisable = iio_triggered_buffer_predisable,
386 .postdisable = stk8ba50_buffer_postdisable,
389 static int stk8ba50_probe(struct i2c_client *client,
390 const struct i2c_device_id *id)
393 struct iio_dev *indio_dev;
394 struct stk8ba50_data *data;
396 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
398 dev_err(&client->dev, "iio allocation failed!\n");
402 data = iio_priv(indio_dev);
403 data->client = client;
404 i2c_set_clientdata(client, indio_dev);
405 mutex_init(&data->lock);
407 indio_dev->dev.parent = &client->dev;
408 indio_dev->info = &stk8ba50_info;
409 indio_dev->name = STK8BA50_DRIVER_NAME;
410 indio_dev->modes = INDIO_DIRECT_MODE;
411 indio_dev->channels = stk8ba50_channels;
412 indio_dev->num_channels = ARRAY_SIZE(stk8ba50_channels);
414 /* Reset all registers on startup */
415 ret = i2c_smbus_write_byte_data(client,
416 STK8BA50_REG_SWRST, STK8BA50_RESET_CMD);
418 dev_err(&client->dev, "failed to reset sensor\n");
422 /* The default range is +/-2g */
425 /* The default sampling rate is 1792 Hz (maximum) */
426 data->sample_rate_idx = STK8BA50_SR_1792HZ_IDX;
428 /* Set up interrupts */
429 ret = i2c_smbus_write_byte_data(client,
430 STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
432 dev_err(&client->dev, "failed to set up interrupts\n");
435 ret = i2c_smbus_write_byte_data(client,
436 STK8BA50_REG_INTMAP2, STK8BA50_DREADY_INT_MAP);
438 dev_err(&client->dev, "failed to set up interrupts\n");
442 if (client->irq > 0) {
443 ret = devm_request_threaded_irq(&client->dev, client->irq,
444 stk8ba50_data_rdy_trig_poll,
446 IRQF_TRIGGER_RISING |
451 dev_err(&client->dev, "request irq %d failed\n",
456 data->dready_trig = devm_iio_trigger_alloc(&client->dev,
460 if (!data->dready_trig) {
465 data->dready_trig->dev.parent = &client->dev;
466 data->dready_trig->ops = &stk8ba50_trigger_ops;
467 iio_trigger_set_drvdata(data->dready_trig, indio_dev);
468 ret = iio_trigger_register(data->dready_trig);
470 dev_err(&client->dev, "iio trigger register failed\n");
475 ret = iio_triggered_buffer_setup(indio_dev,
476 iio_pollfunc_store_time,
477 stk8ba50_trigger_handler,
478 &stk8ba50_buffer_setup_ops);
480 dev_err(&client->dev, "iio triggered buffer setup failed\n");
481 goto err_trigger_unregister;
484 ret = iio_device_register(indio_dev);
486 dev_err(&client->dev, "device_register failed\n");
487 goto err_buffer_cleanup;
493 iio_triggered_buffer_cleanup(indio_dev);
494 err_trigger_unregister:
495 if (data->dready_trig)
496 iio_trigger_unregister(data->dready_trig);
498 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
502 static int stk8ba50_remove(struct i2c_client *client)
504 struct iio_dev *indio_dev = i2c_get_clientdata(client);
505 struct stk8ba50_data *data = iio_priv(indio_dev);
507 iio_device_unregister(indio_dev);
508 iio_triggered_buffer_cleanup(indio_dev);
510 if (data->dready_trig)
511 iio_trigger_unregister(data->dready_trig);
513 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
516 #ifdef CONFIG_PM_SLEEP
517 static int stk8ba50_suspend(struct device *dev)
519 struct stk8ba50_data *data;
521 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
523 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
526 static int stk8ba50_resume(struct device *dev)
528 struct stk8ba50_data *data;
530 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
532 return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
535 static SIMPLE_DEV_PM_OPS(stk8ba50_pm_ops, stk8ba50_suspend, stk8ba50_resume);
537 #define STK8BA50_PM_OPS (&stk8ba50_pm_ops)
539 #define STK8BA50_PM_OPS NULL
542 static const struct i2c_device_id stk8ba50_i2c_id[] = {
546 MODULE_DEVICE_TABLE(i2c, stk8ba50_i2c_id);
548 static const struct acpi_device_id stk8ba50_acpi_id[] = {
553 MODULE_DEVICE_TABLE(acpi, stk8ba50_acpi_id);
555 static struct i2c_driver stk8ba50_driver = {
558 .pm = STK8BA50_PM_OPS,
559 .acpi_match_table = ACPI_PTR(stk8ba50_acpi_id),
561 .probe = stk8ba50_probe,
562 .remove = stk8ba50_remove,
563 .id_table = stk8ba50_i2c_id,
566 module_i2c_driver(stk8ba50_driver);
568 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
569 MODULE_DESCRIPTION("STK8BA50 3-Axis Accelerometer driver");
570 MODULE_LICENSE("GPL v2");