1 // SPDX-License-Identifier: GPL-2.0-only
3 * Sensortek STK8BA50 3-Axis Accelerometer
5 * Copyright (c) 2015, Intel Corporation.
7 * STK8BA50 7-bit I2C address: 0x18.
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/iio/buffer.h>
16 #include <linux/iio/iio.h>
17 #include <linux/iio/sysfs.h>
18 #include <linux/iio/trigger.h>
19 #include <linux/iio/triggered_buffer.h>
20 #include <linux/iio/trigger_consumer.h>
22 #define STK8BA50_REG_XOUT 0x02
23 #define STK8BA50_REG_YOUT 0x04
24 #define STK8BA50_REG_ZOUT 0x06
25 #define STK8BA50_REG_RANGE 0x0F
26 #define STK8BA50_REG_BWSEL 0x10
27 #define STK8BA50_REG_POWMODE 0x11
28 #define STK8BA50_REG_SWRST 0x14
29 #define STK8BA50_REG_INTEN2 0x17
30 #define STK8BA50_REG_INTMAP2 0x1A
32 #define STK8BA50_MODE_NORMAL 0
33 #define STK8BA50_MODE_SUSPEND 1
34 #define STK8BA50_MODE_POWERBIT BIT(7)
35 #define STK8BA50_DATA_SHIFT 6
36 #define STK8BA50_RESET_CMD 0xB6
37 #define STK8BA50_SR_1792HZ_IDX 7
38 #define STK8BA50_DREADY_INT_MASK 0x10
39 #define STK8BA50_DREADY_INT_MAP 0x81
40 #define STK8BA50_ALL_CHANNEL_MASK 7
41 #define STK8BA50_ALL_CHANNEL_SIZE 6
43 #define STK8BA50_DRIVER_NAME "stk8ba50"
44 #define STK8BA50_IRQ_NAME "stk8ba50_event"
46 #define STK8BA50_SCALE_AVAIL "0.0384 0.0767 0.1534 0.3069"
49 * The accelerometer has four measurement ranges:
50 * +/-2g; +/-4g; +/-8g; +/-16g
52 * Acceleration values are 10-bit, 2's complement.
53 * Scales are calculated as following:
55 * scale1 = (2 + 2) * 9.81 / (2^10 - 1) = 0.0384
56 * scale2 = (4 + 4) * 9.81 / (2^10 - 1) = 0.0767
59 * Scales are stored in this format:
60 * { <register value>, <scale value> }
62 * Locally, the range is stored as a table index.
67 } stk8ba50_scale_table[] = {
68 {3, 38400}, {5, 76700}, {8, 153400}, {12, 306900}
71 /* Sample rates are stored as { <register value>, <Hz value> } */
75 } stk8ba50_samp_freq_table[] = {
76 {0x08, 14}, {0x09, 25}, {0x0A, 56}, {0x0B, 112},
77 {0x0C, 224}, {0x0D, 448}, {0x0E, 896}, {0x0F, 1792}
80 /* Used to map scan mask bits to their corresponding channel register. */
81 static const int stk8ba50_channel_table[] = {
87 struct stk8ba50_data {
88 struct i2c_client *client;
92 struct iio_trigger *dready_trig;
93 bool dready_trigger_on;
94 /* Ensure timestamp is naturally aligned */
97 s64 timetamp __aligned(8);
101 #define STK8BA50_ACCEL_CHANNEL(index, reg, axis) { \
105 .channel2 = IIO_MOD_##axis, \
106 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
107 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
108 BIT(IIO_CHAN_INFO_SAMP_FREQ), \
109 .scan_index = index, \
114 .shift = STK8BA50_DATA_SHIFT, \
115 .endianness = IIO_CPU, \
119 static const struct iio_chan_spec stk8ba50_channels[] = {
120 STK8BA50_ACCEL_CHANNEL(0, STK8BA50_REG_XOUT, X),
121 STK8BA50_ACCEL_CHANNEL(1, STK8BA50_REG_YOUT, Y),
122 STK8BA50_ACCEL_CHANNEL(2, STK8BA50_REG_ZOUT, Z),
123 IIO_CHAN_SOFT_TIMESTAMP(3),
126 static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL);
128 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("14 25 56 112 224 448 896 1792");
130 static struct attribute *stk8ba50_attributes[] = {
131 &iio_const_attr_in_accel_scale_available.dev_attr.attr,
132 &iio_const_attr_sampling_frequency_available.dev_attr.attr,
136 static const struct attribute_group stk8ba50_attribute_group = {
137 .attrs = stk8ba50_attributes
140 static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg)
143 struct i2c_client *client = data->client;
145 ret = i2c_smbus_read_word_data(client, reg);
147 dev_err(&client->dev, "register read failed\n");
154 static int stk8ba50_data_rdy_trigger_set_state(struct iio_trigger *trig,
157 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
158 struct stk8ba50_data *data = iio_priv(indio_dev);
162 ret = i2c_smbus_write_byte_data(data->client,
163 STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
165 ret = i2c_smbus_write_byte_data(data->client,
166 STK8BA50_REG_INTEN2, 0x00);
169 dev_err(&data->client->dev, "failed to set trigger state\n");
171 data->dready_trigger_on = state;
176 static const struct iio_trigger_ops stk8ba50_trigger_ops = {
177 .set_trigger_state = stk8ba50_data_rdy_trigger_set_state,
180 static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode)
184 struct i2c_client *client = data->client;
186 ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE);
191 masked_reg = ret | STK8BA50_MODE_POWERBIT;
193 masked_reg = ret & (~STK8BA50_MODE_POWERBIT);
195 ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE,
203 dev_err(&client->dev, "failed to change sensor mode\n");
207 static int stk8ba50_read_raw(struct iio_dev *indio_dev,
208 struct iio_chan_spec const *chan,
209 int *val, int *val2, long mask)
211 struct stk8ba50_data *data = iio_priv(indio_dev);
215 case IIO_CHAN_INFO_RAW:
216 if (iio_buffer_enabled(indio_dev))
218 mutex_lock(&data->lock);
219 ret = stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
221 mutex_unlock(&data->lock);
224 ret = stk8ba50_read_accel(data, chan->address);
226 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
227 mutex_unlock(&data->lock);
230 *val = sign_extend32(ret >> STK8BA50_DATA_SHIFT, 9);
231 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
232 mutex_unlock(&data->lock);
234 case IIO_CHAN_INFO_SCALE:
236 *val2 = stk8ba50_scale_table[data->range].scale_val;
237 return IIO_VAL_INT_PLUS_MICRO;
238 case IIO_CHAN_INFO_SAMP_FREQ:
239 *val = stk8ba50_samp_freq_table
240 [data->sample_rate_idx].samp_freq;
248 static int stk8ba50_write_raw(struct iio_dev *indio_dev,
249 struct iio_chan_spec const *chan,
250 int val, int val2, long mask)
255 struct stk8ba50_data *data = iio_priv(indio_dev);
258 case IIO_CHAN_INFO_SCALE:
262 for (i = 0; i < ARRAY_SIZE(stk8ba50_scale_table); i++)
263 if (val2 == stk8ba50_scale_table[i].scale_val) {
270 ret = i2c_smbus_write_byte_data(data->client,
272 stk8ba50_scale_table[index].reg_val);
274 dev_err(&data->client->dev,
275 "failed to set measurement range\n");
280 case IIO_CHAN_INFO_SAMP_FREQ:
281 for (i = 0; i < ARRAY_SIZE(stk8ba50_samp_freq_table); i++)
282 if (val == stk8ba50_samp_freq_table[i].samp_freq) {
289 ret = i2c_smbus_write_byte_data(data->client,
291 stk8ba50_samp_freq_table[index].reg_val);
293 dev_err(&data->client->dev,
294 "failed to set sampling rate\n");
296 data->sample_rate_idx = index;
304 static const struct iio_info stk8ba50_info = {
305 .read_raw = stk8ba50_read_raw,
306 .write_raw = stk8ba50_write_raw,
307 .attrs = &stk8ba50_attribute_group,
310 static irqreturn_t stk8ba50_trigger_handler(int irq, void *p)
312 struct iio_poll_func *pf = p;
313 struct iio_dev *indio_dev = pf->indio_dev;
314 struct stk8ba50_data *data = iio_priv(indio_dev);
317 mutex_lock(&data->lock);
319 * Do a bulk read if all channels are requested,
320 * from 0x02 (XOUT1) to 0x07 (ZOUT2)
322 if (*(indio_dev->active_scan_mask) == STK8BA50_ALL_CHANNEL_MASK) {
323 ret = i2c_smbus_read_i2c_block_data(data->client,
325 STK8BA50_ALL_CHANNEL_SIZE,
326 (u8 *)data->scan.chans);
327 if (ret < STK8BA50_ALL_CHANNEL_SIZE) {
328 dev_err(&data->client->dev, "register read failed\n");
332 for_each_set_bit(bit, indio_dev->active_scan_mask,
333 indio_dev->masklength) {
334 ret = stk8ba50_read_accel(data,
335 stk8ba50_channel_table[bit]);
339 data->scan.chans[i++] = ret;
342 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
345 mutex_unlock(&data->lock);
346 iio_trigger_notify_done(indio_dev->trig);
351 static irqreturn_t stk8ba50_data_rdy_trig_poll(int irq, void *private)
353 struct iio_dev *indio_dev = private;
354 struct stk8ba50_data *data = iio_priv(indio_dev);
356 if (data->dready_trigger_on)
357 iio_trigger_poll(data->dready_trig);
362 static int stk8ba50_buffer_preenable(struct iio_dev *indio_dev)
364 struct stk8ba50_data *data = iio_priv(indio_dev);
366 return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
369 static int stk8ba50_buffer_postdisable(struct iio_dev *indio_dev)
371 struct stk8ba50_data *data = iio_priv(indio_dev);
373 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
376 static const struct iio_buffer_setup_ops stk8ba50_buffer_setup_ops = {
377 .preenable = stk8ba50_buffer_preenable,
378 .postdisable = stk8ba50_buffer_postdisable,
381 static int stk8ba50_probe(struct i2c_client *client,
382 const struct i2c_device_id *id)
385 struct iio_dev *indio_dev;
386 struct stk8ba50_data *data;
388 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
390 dev_err(&client->dev, "iio allocation failed!\n");
394 data = iio_priv(indio_dev);
395 data->client = client;
396 i2c_set_clientdata(client, indio_dev);
397 mutex_init(&data->lock);
399 indio_dev->info = &stk8ba50_info;
400 indio_dev->name = STK8BA50_DRIVER_NAME;
401 indio_dev->modes = INDIO_DIRECT_MODE;
402 indio_dev->channels = stk8ba50_channels;
403 indio_dev->num_channels = ARRAY_SIZE(stk8ba50_channels);
405 /* Reset all registers on startup */
406 ret = i2c_smbus_write_byte_data(client,
407 STK8BA50_REG_SWRST, STK8BA50_RESET_CMD);
409 dev_err(&client->dev, "failed to reset sensor\n");
413 /* The default range is +/-2g */
416 /* The default sampling rate is 1792 Hz (maximum) */
417 data->sample_rate_idx = STK8BA50_SR_1792HZ_IDX;
419 /* Set up interrupts */
420 ret = i2c_smbus_write_byte_data(client,
421 STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
423 dev_err(&client->dev, "failed to set up interrupts\n");
426 ret = i2c_smbus_write_byte_data(client,
427 STK8BA50_REG_INTMAP2, STK8BA50_DREADY_INT_MAP);
429 dev_err(&client->dev, "failed to set up interrupts\n");
433 if (client->irq > 0) {
434 ret = devm_request_threaded_irq(&client->dev, client->irq,
435 stk8ba50_data_rdy_trig_poll,
437 IRQF_TRIGGER_RISING |
442 dev_err(&client->dev, "request irq %d failed\n",
447 data->dready_trig = devm_iio_trigger_alloc(&client->dev,
451 if (!data->dready_trig) {
456 data->dready_trig->dev.parent = &client->dev;
457 data->dready_trig->ops = &stk8ba50_trigger_ops;
458 iio_trigger_set_drvdata(data->dready_trig, indio_dev);
459 ret = iio_trigger_register(data->dready_trig);
461 dev_err(&client->dev, "iio trigger register failed\n");
466 ret = iio_triggered_buffer_setup(indio_dev,
467 iio_pollfunc_store_time,
468 stk8ba50_trigger_handler,
469 &stk8ba50_buffer_setup_ops);
471 dev_err(&client->dev, "iio triggered buffer setup failed\n");
472 goto err_trigger_unregister;
475 ret = iio_device_register(indio_dev);
477 dev_err(&client->dev, "device_register failed\n");
478 goto err_buffer_cleanup;
484 iio_triggered_buffer_cleanup(indio_dev);
485 err_trigger_unregister:
486 if (data->dready_trig)
487 iio_trigger_unregister(data->dready_trig);
489 stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
493 static int stk8ba50_remove(struct i2c_client *client)
495 struct iio_dev *indio_dev = i2c_get_clientdata(client);
496 struct stk8ba50_data *data = iio_priv(indio_dev);
498 iio_device_unregister(indio_dev);
499 iio_triggered_buffer_cleanup(indio_dev);
501 if (data->dready_trig)
502 iio_trigger_unregister(data->dready_trig);
504 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
507 #ifdef CONFIG_PM_SLEEP
508 static int stk8ba50_suspend(struct device *dev)
510 struct stk8ba50_data *data;
512 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
514 return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
517 static int stk8ba50_resume(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_NORMAL);
526 static SIMPLE_DEV_PM_OPS(stk8ba50_pm_ops, stk8ba50_suspend, stk8ba50_resume);
528 #define STK8BA50_PM_OPS (&stk8ba50_pm_ops)
530 #define STK8BA50_PM_OPS NULL
533 static const struct i2c_device_id stk8ba50_i2c_id[] = {
537 MODULE_DEVICE_TABLE(i2c, stk8ba50_i2c_id);
539 static const struct acpi_device_id stk8ba50_acpi_id[] = {
544 MODULE_DEVICE_TABLE(acpi, stk8ba50_acpi_id);
546 static struct i2c_driver stk8ba50_driver = {
549 .pm = STK8BA50_PM_OPS,
550 .acpi_match_table = ACPI_PTR(stk8ba50_acpi_id),
552 .probe = stk8ba50_probe,
553 .remove = stk8ba50_remove,
554 .id_table = stk8ba50_i2c_id,
557 module_i2c_driver(stk8ba50_driver);
559 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
560 MODULE_DESCRIPTION("STK8BA50 3-Axis Accelerometer driver");
561 MODULE_LICENSE("GPL v2");