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;
97 /* Ensure timestamp is naturally aligned */
100 s64 timetamp __aligned(8);
104 #define STK8BA50_ACCEL_CHANNEL(index, reg, axis) { \
108 .channel2 = IIO_MOD_##axis, \
109 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
110 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
111 BIT(IIO_CHAN_INFO_SAMP_FREQ), \
112 .scan_index = index, \
117 .shift = STK8BA50_DATA_SHIFT, \
118 .endianness = IIO_CPU, \
122 static const struct iio_chan_spec stk8ba50_channels[] = {
123 STK8BA50_ACCEL_CHANNEL(0, STK8BA50_REG_XOUT, X),
124 STK8BA50_ACCEL_CHANNEL(1, STK8BA50_REG_YOUT, Y),
125 STK8BA50_ACCEL_CHANNEL(2, STK8BA50_REG_ZOUT, Z),
126 IIO_CHAN_SOFT_TIMESTAMP(3),
129 static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL);
131 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("14 25 56 112 224 448 896 1792");
133 static struct attribute *stk8ba50_attributes[] = {
134 &iio_const_attr_in_accel_scale_available.dev_attr.attr,
135 &iio_const_attr_sampling_frequency_available.dev_attr.attr,
139 static const struct attribute_group stk8ba50_attribute_group = {
140 .attrs = stk8ba50_attributes
143 static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg)
146 struct i2c_client *client = data->client;
148 ret = i2c_smbus_read_word_data(client, reg);
150 dev_err(&client->dev, "register read failed\n");
157 static int stk8ba50_data_rdy_trigger_set_state(struct iio_trigger *trig,
160 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
161 struct stk8ba50_data *data = iio_priv(indio_dev);
165 ret = i2c_smbus_write_byte_data(data->client,
166 STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
168 ret = i2c_smbus_write_byte_data(data->client,
169 STK8BA50_REG_INTEN2, 0x00);
172 dev_err(&data->client->dev, "failed to set trigger state\n");
174 data->dready_trigger_on = state;
179 static const struct iio_trigger_ops stk8ba50_trigger_ops = {
180 .set_trigger_state = stk8ba50_data_rdy_trigger_set_state,
183 static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode)
187 struct i2c_client *client = data->client;
189 ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE);
194 masked_reg = ret | STK8BA50_MODE_POWERBIT;
196 masked_reg = ret & (~STK8BA50_MODE_POWERBIT);
198 ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE,
206 dev_err(&client->dev, "failed to change sensor mode\n");
210 static int stk8ba50_read_raw(struct iio_dev *indio_dev,
211 struct iio_chan_spec const *chan,
212 int *val, int *val2, long mask)
214 struct stk8ba50_data *data = iio_priv(indio_dev);
218 case IIO_CHAN_INFO_RAW:
219 if (iio_buffer_enabled(indio_dev))
221 mutex_lock(&data->lock);
222 ret = stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
224 mutex_unlock(&data->lock);
227 ret = stk8ba50_read_accel(data, chan->address);
229 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
230 mutex_unlock(&data->lock);
233 *val = sign_extend32(ret >> STK8BA50_DATA_SHIFT, 9);
234 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
235 mutex_unlock(&data->lock);
237 case IIO_CHAN_INFO_SCALE:
239 *val2 = stk8ba50_scale_table[data->range].scale_val;
240 return IIO_VAL_INT_PLUS_MICRO;
241 case IIO_CHAN_INFO_SAMP_FREQ:
242 *val = stk8ba50_samp_freq_table
243 [data->sample_rate_idx].samp_freq;
251 static int stk8ba50_write_raw(struct iio_dev *indio_dev,
252 struct iio_chan_spec const *chan,
253 int val, int val2, long mask)
258 struct stk8ba50_data *data = iio_priv(indio_dev);
261 case IIO_CHAN_INFO_SCALE:
265 for (i = 0; i < ARRAY_SIZE(stk8ba50_scale_table); i++)
266 if (val2 == stk8ba50_scale_table[i].scale_val) {
273 ret = i2c_smbus_write_byte_data(data->client,
275 stk8ba50_scale_table[index].reg_val);
277 dev_err(&data->client->dev,
278 "failed to set measurement range\n");
283 case IIO_CHAN_INFO_SAMP_FREQ:
284 for (i = 0; i < ARRAY_SIZE(stk8ba50_samp_freq_table); i++)
285 if (val == stk8ba50_samp_freq_table[i].samp_freq) {
292 ret = i2c_smbus_write_byte_data(data->client,
294 stk8ba50_samp_freq_table[index].reg_val);
296 dev_err(&data->client->dev,
297 "failed to set sampling rate\n");
299 data->sample_rate_idx = index;
307 static const struct iio_info stk8ba50_info = {
308 .read_raw = stk8ba50_read_raw,
309 .write_raw = stk8ba50_write_raw,
310 .attrs = &stk8ba50_attribute_group,
313 static irqreturn_t stk8ba50_trigger_handler(int irq, void *p)
315 struct iio_poll_func *pf = p;
316 struct iio_dev *indio_dev = pf->indio_dev;
317 struct stk8ba50_data *data = iio_priv(indio_dev);
320 mutex_lock(&data->lock);
322 * Do a bulk read if all channels are requested,
323 * from 0x02 (XOUT1) to 0x07 (ZOUT2)
325 if (*(indio_dev->active_scan_mask) == STK8BA50_ALL_CHANNEL_MASK) {
326 ret = i2c_smbus_read_i2c_block_data(data->client,
328 STK8BA50_ALL_CHANNEL_SIZE,
329 (u8 *)data->scan.chans);
330 if (ret < STK8BA50_ALL_CHANNEL_SIZE) {
331 dev_err(&data->client->dev, "register read failed\n");
335 for_each_set_bit(bit, indio_dev->active_scan_mask,
336 indio_dev->masklength) {
337 ret = stk8ba50_read_accel(data,
338 stk8ba50_channel_table[bit]);
342 data->scan.chans[i++] = ret;
345 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
348 mutex_unlock(&data->lock);
349 iio_trigger_notify_done(indio_dev->trig);
354 static irqreturn_t stk8ba50_data_rdy_trig_poll(int irq, void *private)
356 struct iio_dev *indio_dev = private;
357 struct stk8ba50_data *data = iio_priv(indio_dev);
359 if (data->dready_trigger_on)
360 iio_trigger_poll(data->dready_trig);
365 static int stk8ba50_buffer_preenable(struct iio_dev *indio_dev)
367 struct stk8ba50_data *data = iio_priv(indio_dev);
369 return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
372 static int stk8ba50_buffer_postdisable(struct iio_dev *indio_dev)
374 struct stk8ba50_data *data = iio_priv(indio_dev);
376 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
379 static const struct iio_buffer_setup_ops stk8ba50_buffer_setup_ops = {
380 .preenable = stk8ba50_buffer_preenable,
381 .postenable = iio_triggered_buffer_postenable,
382 .predisable = iio_triggered_buffer_predisable,
383 .postdisable = stk8ba50_buffer_postdisable,
386 static int stk8ba50_probe(struct i2c_client *client,
387 const struct i2c_device_id *id)
390 struct iio_dev *indio_dev;
391 struct stk8ba50_data *data;
393 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
395 dev_err(&client->dev, "iio allocation failed!\n");
399 data = iio_priv(indio_dev);
400 data->client = client;
401 i2c_set_clientdata(client, indio_dev);
402 mutex_init(&data->lock);
404 indio_dev->dev.parent = &client->dev;
405 indio_dev->info = &stk8ba50_info;
406 indio_dev->name = STK8BA50_DRIVER_NAME;
407 indio_dev->modes = INDIO_DIRECT_MODE;
408 indio_dev->channels = stk8ba50_channels;
409 indio_dev->num_channels = ARRAY_SIZE(stk8ba50_channels);
411 /* Reset all registers on startup */
412 ret = i2c_smbus_write_byte_data(client,
413 STK8BA50_REG_SWRST, STK8BA50_RESET_CMD);
415 dev_err(&client->dev, "failed to reset sensor\n");
419 /* The default range is +/-2g */
422 /* The default sampling rate is 1792 Hz (maximum) */
423 data->sample_rate_idx = STK8BA50_SR_1792HZ_IDX;
425 /* Set up interrupts */
426 ret = i2c_smbus_write_byte_data(client,
427 STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
429 dev_err(&client->dev, "failed to set up interrupts\n");
432 ret = i2c_smbus_write_byte_data(client,
433 STK8BA50_REG_INTMAP2, STK8BA50_DREADY_INT_MAP);
435 dev_err(&client->dev, "failed to set up interrupts\n");
439 if (client->irq > 0) {
440 ret = devm_request_threaded_irq(&client->dev, client->irq,
441 stk8ba50_data_rdy_trig_poll,
443 IRQF_TRIGGER_RISING |
448 dev_err(&client->dev, "request irq %d failed\n",
453 data->dready_trig = devm_iio_trigger_alloc(&client->dev,
457 if (!data->dready_trig) {
462 data->dready_trig->dev.parent = &client->dev;
463 data->dready_trig->ops = &stk8ba50_trigger_ops;
464 iio_trigger_set_drvdata(data->dready_trig, indio_dev);
465 ret = iio_trigger_register(data->dready_trig);
467 dev_err(&client->dev, "iio trigger register failed\n");
472 ret = iio_triggered_buffer_setup(indio_dev,
473 iio_pollfunc_store_time,
474 stk8ba50_trigger_handler,
475 &stk8ba50_buffer_setup_ops);
477 dev_err(&client->dev, "iio triggered buffer setup failed\n");
478 goto err_trigger_unregister;
481 ret = iio_device_register(indio_dev);
483 dev_err(&client->dev, "device_register failed\n");
484 goto err_buffer_cleanup;
490 iio_triggered_buffer_cleanup(indio_dev);
491 err_trigger_unregister:
492 if (data->dready_trig)
493 iio_trigger_unregister(data->dready_trig);
495 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
499 static int stk8ba50_remove(struct i2c_client *client)
501 struct iio_dev *indio_dev = i2c_get_clientdata(client);
502 struct stk8ba50_data *data = iio_priv(indio_dev);
504 iio_device_unregister(indio_dev);
505 iio_triggered_buffer_cleanup(indio_dev);
507 if (data->dready_trig)
508 iio_trigger_unregister(data->dready_trig);
510 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
513 #ifdef CONFIG_PM_SLEEP
514 static int stk8ba50_suspend(struct device *dev)
516 struct stk8ba50_data *data;
518 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
520 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
523 static int stk8ba50_resume(struct device *dev)
525 struct stk8ba50_data *data;
527 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
529 return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
532 static SIMPLE_DEV_PM_OPS(stk8ba50_pm_ops, stk8ba50_suspend, stk8ba50_resume);
534 #define STK8BA50_PM_OPS (&stk8ba50_pm_ops)
536 #define STK8BA50_PM_OPS NULL
539 static const struct i2c_device_id stk8ba50_i2c_id[] = {
543 MODULE_DEVICE_TABLE(i2c, stk8ba50_i2c_id);
545 static const struct acpi_device_id stk8ba50_acpi_id[] = {
550 MODULE_DEVICE_TABLE(acpi, stk8ba50_acpi_id);
552 static struct i2c_driver stk8ba50_driver = {
555 .pm = STK8BA50_PM_OPS,
556 .acpi_match_table = ACPI_PTR(stk8ba50_acpi_id),
558 .probe = stk8ba50_probe,
559 .remove = stk8ba50_remove,
560 .id_table = stk8ba50_i2c_id,
563 module_i2c_driver(stk8ba50_driver);
565 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
566 MODULE_DESCRIPTION("STK8BA50 3-Axis Accelerometer driver");
567 MODULE_LICENSE("GPL v2");