stk8ba50.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Sensortek STK8BA50 3-Axis Accelerometer
  4 *
  5 * Copyright (c) 2015, Intel Corporation.
  6 *
  7 * STK8BA50 7-bit I2C address: 0x18.
  8 */
  9
 10#include <linux/i2c.h>
 11#include <linux/interrupt.h>
 12#include <linux/kernel.h>
 13#include <linux/module.h>
 14#include <linux/mod_devicetable.h>
 15#include <linux/types.h>
 16#include <linux/iio/buffer.h>
 17#include <linux/iio/iio.h>
 18#include <linux/iio/sysfs.h>
 19#include <linux/iio/trigger.h>
 20#include <linux/iio/triggered_buffer.h>
 21#include <linux/iio/trigger_consumer.h>
 22
 23#define STK8BA50_REG_XOUT			0x02
 24#define STK8BA50_REG_YOUT			0x04
 25#define STK8BA50_REG_ZOUT			0x06
 26#define STK8BA50_REG_RANGE			0x0F
 27#define STK8BA50_REG_BWSEL			0x10
 28#define STK8BA50_REG_POWMODE			0x11
 29#define STK8BA50_REG_SWRST			0x14
 30#define STK8BA50_REG_INTEN2			0x17
 31#define STK8BA50_REG_INTMAP2			0x1A
 32
 33#define STK8BA50_MODE_NORMAL			0
 34#define STK8BA50_MODE_SUSPEND			1
 35#define STK8BA50_MODE_POWERBIT			BIT(7)
 36#define STK8BA50_DATA_SHIFT			6
 37#define STK8BA50_RESET_CMD			0xB6
 38#define STK8BA50_SR_1792HZ_IDX			7
 39#define STK8BA50_DREADY_INT_MASK		0x10
 40#define STK8BA50_DREADY_INT_MAP			0x81
 41#define STK8BA50_ALL_CHANNEL_MASK		7
 42#define STK8BA50_ALL_CHANNEL_SIZE		6
 43
 44#define STK8BA50_DRIVER_NAME			"stk8ba50"
 45
 46#define STK8BA50_SCALE_AVAIL			"0.0384 0.0767 0.1534 0.3069"
 47
 48/*
 49 * The accelerometer has four measurement ranges:
 50 * +/-2g; +/-4g; +/-8g; +/-16g
 51 *
 52 * Acceleration values are 10-bit, 2's complement.
 53 * Scales are calculated as following:
 54 *
 55 * scale1 = (2 + 2) * 9.81 / (2^10 - 1)   = 0.0384
 56 * scale2 = (4 + 4) * 9.81 / (2^10 - 1)   = 0.0767
 57 * etc.
 58 *
 59 * Scales are stored in this format:
 60 * { <register value>, <scale value> }
 61 *
 62 * Locally, the range is stored as a table index.
 63 */
 64static const struct {
 65	u8 reg_val;
 66	u32 scale_val;
 67} stk8ba50_scale_table[] = {
 68	{3, 38400}, {5, 76700}, {8, 153400}, {12, 306900}
 69};
 70
 71/* Sample rates are stored as { <register value>, <Hz value> } */
 72static const struct {
 73	u8 reg_val;
 74	u16 samp_freq;
 75} stk8ba50_samp_freq_table[] = {
 76	{0x08, 14},  {0x09, 25},  {0x0A, 56},  {0x0B, 112},
 77	{0x0C, 224}, {0x0D, 448}, {0x0E, 896}, {0x0F, 1792}
 78};
 79
 80/* Used to map scan mask bits to their corresponding channel register. */
 81static const int stk8ba50_channel_table[] = {
 82	STK8BA50_REG_XOUT,
 83	STK8BA50_REG_YOUT,
 84	STK8BA50_REG_ZOUT
 85};
 86
 87struct stk8ba50_data {
 88	struct i2c_client *client;
 89	struct mutex lock;
 90	int range;
 91	u8 sample_rate_idx;
 92	struct iio_trigger *dready_trig;
 93	bool dready_trigger_on;
 94	/* Ensure timestamp is naturally aligned */
 95	struct {
 96		s16 chans[3];
 97		aligned_s64 timetamp;
 98	} scan;
 99};
100
101#define STK8BA50_ACCEL_CHANNEL(index, reg, axis) {			\
102	.type = IIO_ACCEL,						\
103	.address = reg,							\
104	.modified = 1,							\
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,						\
110	.scan_type = {							\
111		.sign = 's',						\
112		.realbits = 10,						\
113		.storagebits = 16,					\
114		.shift = STK8BA50_DATA_SHIFT,				\
115		.endianness = IIO_CPU,					\
116	},								\
117}
118
119static 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),
124};
125
126static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL);
127
128static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("14 25 56 112 224 448 896 1792");
129
130static 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,
133	NULL,
134};
135
136static const struct attribute_group stk8ba50_attribute_group = {
137	.attrs = stk8ba50_attributes
138};
139
140static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg)
141{
142	int ret;
143	struct i2c_client *client = data->client;
144
145	ret = i2c_smbus_read_word_data(client, reg);
146	if (ret < 0) {
147		dev_err(&client->dev, "register read failed\n");
148		return ret;
149	}
150
151	return ret;
152}
153
154static int stk8ba50_data_rdy_trigger_set_state(struct iio_trigger *trig,
155					       bool state)
156{
157	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
158	struct stk8ba50_data *data = iio_priv(indio_dev);
159	int ret;
160
161	if (state)
162		ret = i2c_smbus_write_byte_data(data->client,
163			STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
164	else
165		ret = i2c_smbus_write_byte_data(data->client,
166			STK8BA50_REG_INTEN2, 0x00);
167
168	if (ret < 0)
169		dev_err(&data->client->dev, "failed to set trigger state\n");
170	else
171		data->dready_trigger_on = state;
172
173	return ret;
174}
175
176static const struct iio_trigger_ops stk8ba50_trigger_ops = {
177	.set_trigger_state = stk8ba50_data_rdy_trigger_set_state,
178};
179
180static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode)
181{
182	int ret;
183	u8 masked_reg;
184	struct i2c_client *client = data->client;
185
186	ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE);
187	if (ret < 0)
188		goto exit_err;
189
190	if (mode)
191		masked_reg = ret | STK8BA50_MODE_POWERBIT;
192	else
193		masked_reg = ret & (~STK8BA50_MODE_POWERBIT);
194
195	ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE,
196					masked_reg);
197	if (ret < 0)
198		goto exit_err;
199
200	return ret;
201
202exit_err:
203	dev_err(&client->dev, "failed to change sensor mode\n");
204	return ret;
205}
206
207static int stk8ba50_read_raw(struct iio_dev *indio_dev,
208			     struct iio_chan_spec const *chan,
209			     int *val, int *val2, long mask)
210{
211	struct stk8ba50_data *data = iio_priv(indio_dev);
212	int ret;
213
214	switch (mask) {
215	case IIO_CHAN_INFO_RAW:
216		if (iio_buffer_enabled(indio_dev))
217			return -EBUSY;
218		mutex_lock(&data->lock);
219		ret = stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
220		if (ret < 0) {
221			mutex_unlock(&data->lock);
222			return -EINVAL;
223		}
224		ret = stk8ba50_read_accel(data, chan->address);
225		if (ret < 0) {
226			stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
227			mutex_unlock(&data->lock);
228			return -EINVAL;
229		}
230		*val = sign_extend32(ret >> chan->scan_type.shift,
231				     chan->scan_type.realbits - 1);
232		stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
233		mutex_unlock(&data->lock);
234		return IIO_VAL_INT;
235	case IIO_CHAN_INFO_SCALE:
236		*val = 0;
237		*val2 = stk8ba50_scale_table[data->range].scale_val;
238		return IIO_VAL_INT_PLUS_MICRO;
239	case IIO_CHAN_INFO_SAMP_FREQ:
240		*val = stk8ba50_samp_freq_table
241				[data->sample_rate_idx].samp_freq;
242		*val2 = 0;
243		return IIO_VAL_INT;
244	}
245
246	return -EINVAL;
247}
248
249static int stk8ba50_write_raw(struct iio_dev *indio_dev,
250			      struct iio_chan_spec const *chan,
251			      int val, int val2, long mask)
252{
253	int ret;
254	int i;
255	int index = -1;
256	struct stk8ba50_data *data = iio_priv(indio_dev);
257
258	switch (mask) {
259	case IIO_CHAN_INFO_SCALE:
260		if (val != 0)
261			return -EINVAL;
262
263		for (i = 0; i < ARRAY_SIZE(stk8ba50_scale_table); i++)
264			if (val2 == stk8ba50_scale_table[i].scale_val) {
265				index = i;
266				break;
267			}
268		if (index < 0)
269			return -EINVAL;
270
271		ret = i2c_smbus_write_byte_data(data->client,
272				STK8BA50_REG_RANGE,
273				stk8ba50_scale_table[index].reg_val);
274		if (ret < 0)
275			dev_err(&data->client->dev,
276					"failed to set measurement range\n");
277		else
278			data->range = index;
279
280		return ret;
281	case IIO_CHAN_INFO_SAMP_FREQ:
282		for (i = 0; i < ARRAY_SIZE(stk8ba50_samp_freq_table); i++)
283			if (val == stk8ba50_samp_freq_table[i].samp_freq) {
284				index = i;
285				break;
286			}
287		if (index < 0)
288			return -EINVAL;
289
290		ret = i2c_smbus_write_byte_data(data->client,
291				STK8BA50_REG_BWSEL,
292				stk8ba50_samp_freq_table[index].reg_val);
293		if (ret < 0)
294			dev_err(&data->client->dev,
295					"failed to set sampling rate\n");
296		else
297			data->sample_rate_idx = index;
298
299		return ret;
300	}
301
302	return -EINVAL;
303}
304
305static const struct iio_info stk8ba50_info = {
306	.read_raw		= stk8ba50_read_raw,
307	.write_raw		= stk8ba50_write_raw,
308	.attrs			= &stk8ba50_attribute_group,
309};
310
311static irqreturn_t stk8ba50_trigger_handler(int irq, void *p)
312{
313	struct iio_poll_func *pf = p;
314	struct iio_dev *indio_dev = pf->indio_dev;
315	struct stk8ba50_data *data = iio_priv(indio_dev);
316	int bit, ret, i = 0;
317
318	mutex_lock(&data->lock);
319	/*
320	 * Do a bulk read if all channels are requested,
321	 * from 0x02 (XOUT1) to 0x07 (ZOUT2)
322	 */
323	if (*(indio_dev->active_scan_mask) == STK8BA50_ALL_CHANNEL_MASK) {
324		ret = i2c_smbus_read_i2c_block_data(data->client,
325						    STK8BA50_REG_XOUT,
326						    STK8BA50_ALL_CHANNEL_SIZE,
327						    (u8 *)data->scan.chans);
328		if (ret < STK8BA50_ALL_CHANNEL_SIZE) {
329			dev_err(&data->client->dev, "register read failed\n");
330			goto err;
331		}
332	} else {
333		iio_for_each_active_channel(indio_dev, bit) {
334			ret = stk8ba50_read_accel(data,
335						  stk8ba50_channel_table[bit]);
336			if (ret < 0)
337				goto err;
338
339			data->scan.chans[i++] = ret;
340		}
341	}
342	iio_push_to_buffers_with_ts(indio_dev, &data->scan, sizeof(data->scan),
343				    pf->timestamp);
344err:
345	mutex_unlock(&data->lock);
346	iio_trigger_notify_done(indio_dev->trig);
347
348	return IRQ_HANDLED;
349}
350
351static irqreturn_t stk8ba50_data_rdy_trig_poll(int irq, void *private)
352{
353	struct iio_dev *indio_dev = private;
354	struct stk8ba50_data *data = iio_priv(indio_dev);
355
356	if (data->dready_trigger_on)
357		iio_trigger_poll(data->dready_trig);
358
359	return IRQ_HANDLED;
360}
361
362static int stk8ba50_buffer_preenable(struct iio_dev *indio_dev)
363{
364	struct stk8ba50_data *data = iio_priv(indio_dev);
365
366	return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
367}
368
369static int stk8ba50_buffer_postdisable(struct iio_dev *indio_dev)
370{
371	struct stk8ba50_data *data = iio_priv(indio_dev);
372
373	return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
374}
375
376static const struct iio_buffer_setup_ops stk8ba50_buffer_setup_ops = {
377	.preenable   = stk8ba50_buffer_preenable,
378	.postdisable = stk8ba50_buffer_postdisable,
379};
380
381static int stk8ba50_probe(struct i2c_client *client)
382{
383	int ret;
384	struct iio_dev *indio_dev;
385	struct stk8ba50_data *data;
386
387	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
388	if (!indio_dev)
389		return -ENOMEM;
390
391	data = iio_priv(indio_dev);
392	data->client = client;
393	i2c_set_clientdata(client, indio_dev);
394	mutex_init(&data->lock);
395
396	indio_dev->info = &stk8ba50_info;
397	indio_dev->name = STK8BA50_DRIVER_NAME;
398	indio_dev->modes = INDIO_DIRECT_MODE;
399	indio_dev->channels = stk8ba50_channels;
400	indio_dev->num_channels = ARRAY_SIZE(stk8ba50_channels);
401
402	/* Reset all registers on startup */
403	ret = i2c_smbus_write_byte_data(client,
404			STK8BA50_REG_SWRST, STK8BA50_RESET_CMD);
405	if (ret < 0) {
406		dev_err(&client->dev, "failed to reset sensor\n");
407		goto err_power_off;
408	}
409
410	/* The default range is +/-2g */
411	data->range = 0;
412
413	/* The default sampling rate is 1792 Hz (maximum) */
414	data->sample_rate_idx = STK8BA50_SR_1792HZ_IDX;
415
416	/* Set up interrupts */
417	ret = i2c_smbus_write_byte_data(client,
418			STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
419	if (ret < 0) {
420		dev_err(&client->dev, "failed to set up interrupts\n");
421		goto err_power_off;
422	}
423	ret = i2c_smbus_write_byte_data(client,
424			STK8BA50_REG_INTMAP2, STK8BA50_DREADY_INT_MAP);
425	if (ret < 0) {
426		dev_err(&client->dev, "failed to set up interrupts\n");
427		goto err_power_off;
428	}
429
430	if (client->irq > 0) {
431		ret = devm_request_threaded_irq(&client->dev, client->irq,
432						stk8ba50_data_rdy_trig_poll,
433						NULL,
434						IRQF_TRIGGER_RISING |
435						IRQF_ONESHOT,
436						"stk8ba50_event",
437						indio_dev);
438		if (ret < 0) {
439			dev_err(&client->dev, "request irq %d failed\n",
440				client->irq);
441			goto err_power_off;
442		}
443
444		data->dready_trig = devm_iio_trigger_alloc(&client->dev,
445							   "%s-dev%d",
446							   indio_dev->name,
447							   iio_device_id(indio_dev));
448		if (!data->dready_trig) {
449			ret = -ENOMEM;
450			goto err_power_off;
451		}
452
453		data->dready_trig->ops = &stk8ba50_trigger_ops;
454		iio_trigger_set_drvdata(data->dready_trig, indio_dev);
455		ret = iio_trigger_register(data->dready_trig);
456		if (ret) {
457			dev_err(&client->dev, "iio trigger register failed\n");
458			goto err_power_off;
459		}
460	}
461
462	ret = iio_triggered_buffer_setup(indio_dev,
463					 iio_pollfunc_store_time,
464					 stk8ba50_trigger_handler,
465					 &stk8ba50_buffer_setup_ops);
466	if (ret < 0) {
467		dev_err(&client->dev, "iio triggered buffer setup failed\n");
468		goto err_trigger_unregister;
469	}
470
471	ret = iio_device_register(indio_dev);
472	if (ret < 0) {
473		dev_err(&client->dev, "device_register failed\n");
474		goto err_buffer_cleanup;
475	}
476
477	return ret;
478
479err_buffer_cleanup:
480	iio_triggered_buffer_cleanup(indio_dev);
481err_trigger_unregister:
482	if (data->dready_trig)
483		iio_trigger_unregister(data->dready_trig);
484err_power_off:
485	stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
486	return ret;
487}
488
489static void stk8ba50_remove(struct i2c_client *client)
490{
491	struct iio_dev *indio_dev = i2c_get_clientdata(client);
492	struct stk8ba50_data *data = iio_priv(indio_dev);
493
494	iio_device_unregister(indio_dev);
495	iio_triggered_buffer_cleanup(indio_dev);
496
497	if (data->dready_trig)
498		iio_trigger_unregister(data->dready_trig);
499
500	stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
501}
502
503static int stk8ba50_suspend(struct device *dev)
504{
505	struct stk8ba50_data *data;
506
507	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
508
509	return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
510}
511
512static int stk8ba50_resume(struct device *dev)
513{
514	struct stk8ba50_data *data;
515
516	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
517
518	return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
519}
520
521static DEFINE_SIMPLE_DEV_PM_OPS(stk8ba50_pm_ops, stk8ba50_suspend,
522				stk8ba50_resume);
523
524static const struct i2c_device_id stk8ba50_i2c_id[] = {
525	{ "stk8ba50" },
526	{ }
527};
528MODULE_DEVICE_TABLE(i2c, stk8ba50_i2c_id);
529
530static const struct acpi_device_id stk8ba50_acpi_id[] = {
531	{"STK8BA50", 0},
532	{ }
533};
534
535MODULE_DEVICE_TABLE(acpi, stk8ba50_acpi_id);
536
537static struct i2c_driver stk8ba50_driver = {
538	.driver = {
539		.name = "stk8ba50",
540		.pm = pm_sleep_ptr(&stk8ba50_pm_ops),
541		.acpi_match_table = stk8ba50_acpi_id,
542	},
543	.probe =        stk8ba50_probe,
544	.remove =           stk8ba50_remove,
545	.id_table =         stk8ba50_i2c_id,
546};
547
548module_i2c_driver(stk8ba50_driver);
549
550MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
551MODULE_DESCRIPTION("STK8BA50 3-Axis Accelerometer driver");
552MODULE_LICENSE("GPL v2");