st_lsm6dsx_buffer.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * STMicroelectronics st_lsm6dsx FIFO buffer library driver
  4 *
  5 * Pattern FIFO:
  6 * The FIFO buffer can be configured to store data from gyroscope and
  7 * accelerometer. Samples are queued without any tag according to a
  8 * specific pattern based on 'FIFO data sets' (6 bytes each):
  9 *  - 1st data set is reserved for gyroscope data
 10 *  - 2nd data set is reserved for accelerometer data
 11 * The FIFO pattern changes depending on the ODRs and decimation factors
 12 * assigned to the FIFO data sets. The first sequence of data stored in FIFO
 13 * buffer contains the data of all the enabled FIFO data sets
 14 * (e.g. Gx, Gy, Gz, Ax, Ay, Az), then data are repeated depending on the
 15 * value of the decimation factor and ODR set for each FIFO data set.
 16 *
 17 * Supported devices:
 18 * - ISM330DLC
 19 * - LSM6DS3
 20 * - LSM6DS3H
 21 * - LSM6DS3TR-C
 22 * - LSM6DSL
 23 * - LSM6DSM
 24 *
 25 * Tagged FIFO:
 26 * The FIFO buffer can be configured to store data from gyroscope and
 27 * accelerometer. Each sample is queued with a tag (1B) indicating data
 28 * source (gyroscope, accelerometer, hw timer).
 29 *
 30 * Supported devices:
 31 * - ASM330LHB
 32 * - ASM330LHH
 33 * - ASM330LHHX
 34 * - ASM330LHHXG1
 35 * - ISM330DHCX
 36 * - LSM6DSO
 37 * - LSM6DSOP
 38 * - LSM6DSOX
 39 * - LSM6DSR
 40 * - LSM6DSRX
 41 * - LSM6DST
 42 * - LSM6DSTX
 43 * - LSM6DSV
 44 *
 45 * FIFO supported modes:
 46 *  - BYPASS: FIFO disabled
 47 *  - CONTINUOUS: FIFO enabled. When the buffer is full, the FIFO index
 48 *    restarts from the beginning and the oldest sample is overwritten
 49 *
 50 * Copyright 2016 STMicroelectronics Inc.
 51 *
 52 * Lorenzo Bianconi <lorenzo.bianconi@st.com>
 53 * Denis Ciocca <denis.ciocca@st.com>
 54 */
 55#include <linux/module.h>
 56#include <linux/iio/kfifo_buf.h>
 57#include <linux/iio/iio.h>
 58#include <linux/iio/buffer.h>
 59#include <linux/iio/sysfs.h>
 60#include <linux/regmap.h>
 61#include <linux/bitfield.h>
 62
 63#include <linux/platform_data/st_sensors_pdata.h>
 64
 65#include "st_lsm6dsx.h"
 66
 67#define ST_LSM6DSX_REG_FIFO_MODE_ADDR		0x0a
 68#define ST_LSM6DSX_FIFO_MODE_MASK		GENMASK(2, 0)
 69#define ST_LSM6DSX_FIFO_ODR_MASK		GENMASK(6, 3)
 70#define ST_LSM6DSX_FIFO_EMPTY_MASK		BIT(12)
 71#define ST_LSM6DSX_REG_FIFO_OUTL_ADDR		0x3e
 72#define ST_LSM6DSX_REG_FIFO_OUT_TAG_ADDR	0x78
 73#define ST_LSM6DSX_REG_TS_RESET_ADDR		0x42
 74
 75#define ST_LSM6DSX_MAX_FIFO_ODR_VAL		0x08
 76
 77#define ST_LSM6DSX_TS_RESET_VAL			0xaa
 78
 79struct st_lsm6dsx_decimator_entry {
 80	u8 decimator;
 81	u8 val;
 82};
 83
 84enum st_lsm6dsx_fifo_tag {
 85	ST_LSM6DSX_GYRO_TAG = 0x01,
 86	ST_LSM6DSX_ACC_TAG = 0x02,
 87	ST_LSM6DSX_TS_TAG = 0x04,
 88	ST_LSM6DSX_EXT0_TAG = 0x0f,
 89	ST_LSM6DSX_EXT1_TAG = 0x10,
 90	ST_LSM6DSX_EXT2_TAG = 0x11,
 91};
 92
 93static const
 94struct st_lsm6dsx_decimator_entry st_lsm6dsx_decimator_table[] = {
 95	{  0, 0x0 },
 96	{  1, 0x1 },
 97	{  2, 0x2 },
 98	{  3, 0x3 },
 99	{  4, 0x4 },
100	{  8, 0x5 },
101	{ 16, 0x6 },
102	{ 32, 0x7 },
103};
104
105static int
106st_lsm6dsx_get_decimator_val(struct st_lsm6dsx_sensor *sensor, u32 max_odr)
107{
108	const int max_size = ARRAY_SIZE(st_lsm6dsx_decimator_table);
109	u32 decimator = max_odr / sensor->hwfifo_odr_mHz;
110	int i;
111
112	if (decimator > 1)
113		decimator = round_down(decimator, 2);
114
115	for (i = 0; i < max_size; i++) {
116		if (st_lsm6dsx_decimator_table[i].decimator == decimator)
117			break;
118	}
119
120	sensor->decimator = decimator;
121	return i == max_size ? 0 : st_lsm6dsx_decimator_table[i].val;
122}
123
124static void st_lsm6dsx_get_max_min_odr(struct st_lsm6dsx_hw *hw,
125				       u32 *max_odr, u32 *min_odr)
126{
127	struct st_lsm6dsx_sensor *sensor;
128	int i;
129
130	*max_odr = 0, *min_odr = ~0;
131	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
132		if (!hw->iio_devs[i])
133			continue;
134
135		sensor = iio_priv(hw->iio_devs[i]);
136
137		if (!(hw->enable_mask & BIT(sensor->id)))
138			continue;
139
140		*max_odr = max(*max_odr, sensor->hwfifo_odr_mHz);
141		*min_odr = min(*min_odr, sensor->hwfifo_odr_mHz);
142	}
143}
144
145static u8 st_lsm6dsx_get_sip(struct st_lsm6dsx_sensor *sensor, u32 min_odr)
146{
147	u8 sip = sensor->hwfifo_odr_mHz / min_odr;
148
149	return sip > 1 ? round_down(sip, 2) : sip;
150}
151
152static int st_lsm6dsx_update_decimators(struct st_lsm6dsx_hw *hw)
153{
154	const struct st_lsm6dsx_reg *ts_dec_reg;
155	struct st_lsm6dsx_sensor *sensor;
156	u16 sip = 0, ts_sip = 0;
157	u32 max_odr, min_odr;
158	int err = 0, i;
159	u8 data;
160
161	st_lsm6dsx_get_max_min_odr(hw, &max_odr, &min_odr);
162
163	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
164		const struct st_lsm6dsx_reg *dec_reg;
165
166		if (!hw->iio_devs[i])
167			continue;
168
169		sensor = iio_priv(hw->iio_devs[i]);
170		/* update fifo decimators and sample in pattern */
171		if (hw->enable_mask & BIT(sensor->id)) {
172			sensor->sip = st_lsm6dsx_get_sip(sensor, min_odr);
173			data = st_lsm6dsx_get_decimator_val(sensor, max_odr);
174		} else {
175			sensor->sip = 0;
176			data = 0;
177		}
178		ts_sip = max_t(u16, ts_sip, sensor->sip);
179
180		dec_reg = &hw->settings->decimator[sensor->id];
181		if (dec_reg->addr) {
182			int val = ST_LSM6DSX_SHIFT_VAL(data, dec_reg->mask);
183
184			err = st_lsm6dsx_update_bits_locked(hw, dec_reg->addr,
185							    dec_reg->mask,
186							    val);
187			if (err < 0)
188				return err;
189		}
190		sip += sensor->sip;
191	}
192	hw->sip = sip + ts_sip;
193	hw->ts_sip = ts_sip;
194
195	/*
196	 * update hw ts decimator if necessary. Decimator for hw timestamp
197	 * is always 1 or 0 in order to have a ts sample for each data
198	 * sample in FIFO
199	 */
200	ts_dec_reg = &hw->settings->ts_settings.decimator;
201	if (ts_dec_reg->addr) {
202		int val, ts_dec = !!hw->ts_sip;
203
204		val = ST_LSM6DSX_SHIFT_VAL(ts_dec, ts_dec_reg->mask);
205		err = st_lsm6dsx_update_bits_locked(hw, ts_dec_reg->addr,
206						    ts_dec_reg->mask, val);
207	}
208	return err;
209}
210
211static int st_lsm6dsx_set_fifo_mode(struct st_lsm6dsx_hw *hw,
212				    enum st_lsm6dsx_fifo_mode fifo_mode)
213{
214	unsigned int data;
215
216	data = FIELD_PREP(ST_LSM6DSX_FIFO_MODE_MASK, fifo_mode);
217	return st_lsm6dsx_update_bits_locked(hw, ST_LSM6DSX_REG_FIFO_MODE_ADDR,
218					     ST_LSM6DSX_FIFO_MODE_MASK, data);
219}
220
221static int st_lsm6dsx_set_fifo_odr(struct st_lsm6dsx_sensor *sensor,
222				   bool enable)
223{
224	struct st_lsm6dsx_hw *hw = sensor->hw;
225	const struct st_lsm6dsx_reg *batch_reg;
226	u8 data;
227
228	/* Only internal sensors have a FIFO ODR configuration register. */
229	if (sensor->id >= ARRAY_SIZE(hw->settings->batch))
230		return 0;
231
232	batch_reg = &hw->settings->batch[sensor->id];
233	if (batch_reg->addr) {
234		int val;
235
236		if (enable) {
237			int err;
238
239			err = st_lsm6dsx_check_odr(sensor, sensor->hwfifo_odr_mHz,
240						   &data);
241			if (err < 0)
242				return err;
243		} else {
244			data = 0;
245		}
246		val = ST_LSM6DSX_SHIFT_VAL(data, batch_reg->mask);
247		return st_lsm6dsx_update_bits_locked(hw, batch_reg->addr,
248						     batch_reg->mask, val);
249	} else {
250		data = hw->enable_mask ? ST_LSM6DSX_MAX_FIFO_ODR_VAL : 0;
251		return st_lsm6dsx_update_bits_locked(hw,
252					ST_LSM6DSX_REG_FIFO_MODE_ADDR,
253					ST_LSM6DSX_FIFO_ODR_MASK,
254					FIELD_PREP(ST_LSM6DSX_FIFO_ODR_MASK,
255						   data));
256	}
257}
258
259int st_lsm6dsx_update_watermark(struct st_lsm6dsx_sensor *sensor, u16 watermark)
260{
261	u16 fifo_watermark = ~0, cur_watermark, fifo_th_mask;
262	struct st_lsm6dsx_hw *hw = sensor->hw;
263	struct st_lsm6dsx_sensor *cur_sensor;
264	int i, err, data;
265	__le16 wdata;
266
267	if (!hw->sip)
268		return 0;
269
270	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
271		if (!hw->iio_devs[i])
272			continue;
273
274		cur_sensor = iio_priv(hw->iio_devs[i]);
275
276		if (!(hw->enable_mask & BIT(cur_sensor->id)))
277			continue;
278
279		cur_watermark = (cur_sensor == sensor) ? watermark
280						       : cur_sensor->watermark;
281
282		fifo_watermark = min_t(u16, fifo_watermark, cur_watermark);
283	}
284
285	fifo_watermark = max_t(u16, fifo_watermark, hw->sip);
286	fifo_watermark = (fifo_watermark / hw->sip) * hw->sip;
287	fifo_watermark = fifo_watermark * hw->settings->fifo_ops.th_wl;
288
289	mutex_lock(&hw->page_lock);
290	err = regmap_read(hw->regmap, hw->settings->fifo_ops.fifo_th.addr + 1,
291			  &data);
292	if (err < 0)
293		goto out;
294
295	fifo_th_mask = hw->settings->fifo_ops.fifo_th.mask;
296	fifo_watermark = ((data << 8) & ~fifo_th_mask) |
297			 (fifo_watermark & fifo_th_mask);
298
299	wdata = cpu_to_le16(fifo_watermark);
300	err = regmap_bulk_write(hw->regmap,
301				hw->settings->fifo_ops.fifo_th.addr,
302				&wdata, sizeof(wdata));
303out:
304	mutex_unlock(&hw->page_lock);
305	return err;
306}
307
308static int st_lsm6dsx_reset_hw_ts(struct st_lsm6dsx_hw *hw)
309{
310	struct st_lsm6dsx_sensor *sensor;
311	int i, err;
312
313	/* reset hw ts counter */
314	err = st_lsm6dsx_write_locked(hw, ST_LSM6DSX_REG_TS_RESET_ADDR,
315				      ST_LSM6DSX_TS_RESET_VAL);
316	if (err < 0)
317		return err;
318
319	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
320		if (!hw->iio_devs[i])
321			continue;
322
323		sensor = iio_priv(hw->iio_devs[i]);
324		/*
325		 * store enable buffer timestamp as reference for
326		 * hw timestamp
327		 */
328		sensor->ts_ref = iio_get_time_ns(hw->iio_devs[i]);
329	}
330	return 0;
331}
332
333int st_lsm6dsx_resume_fifo(struct st_lsm6dsx_hw *hw)
334{
335	int err;
336
337	/* reset hw ts counter */
338	err = st_lsm6dsx_reset_hw_ts(hw);
339	if (err < 0)
340		return err;
341
342	return st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_CONT);
343}
344
345/*
346 * Set max bulk read to ST_LSM6DSX_MAX_WORD_LEN/ST_LSM6DSX_MAX_TAGGED_WORD_LEN
347 * in order to avoid a kmalloc for each bus access
348 */
349static inline int st_lsm6dsx_read_block(struct st_lsm6dsx_hw *hw, u8 addr,
350					u8 *data, unsigned int data_len,
351					unsigned int max_word_len)
352{
353	unsigned int word_len, read_len = 0;
354	int err;
355
356	while (read_len < data_len) {
357		word_len = min_t(unsigned int, data_len - read_len,
358				 max_word_len);
359		err = st_lsm6dsx_read_locked(hw, addr, data + read_len,
360					     word_len);
361		if (err < 0)
362			return err;
363		read_len += word_len;
364	}
365	return 0;
366}
367
368#define ST_LSM6DSX_IIO_BUFF_SIZE	(ALIGN(ST_LSM6DSX_SAMPLE_SIZE, \
369					       sizeof(s64)) + sizeof(s64))
370/**
371 * st_lsm6dsx_read_fifo() - hw FIFO read routine
372 * @hw: Pointer to instance of struct st_lsm6dsx_hw.
373 *
374 * Read samples from the hw FIFO and push them to IIO buffers.
375 *
376 * Return: Number of bytes read from the FIFO
377 */
378int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw)
379{
380	struct st_lsm6dsx_sensor *acc_sensor, *gyro_sensor, *ext_sensor = NULL;
381	int err, sip, acc_sip, gyro_sip, ts_sip, ext_sip, read_len, offset;
382	u16 fifo_len, pattern_len = hw->sip * ST_LSM6DSX_SAMPLE_SIZE;
383	u16 fifo_diff_mask = hw->settings->fifo_ops.fifo_diff.mask;
384	bool reset_ts = false;
385	__le16 fifo_status;
386	s64 ts = 0;
387
388	err = st_lsm6dsx_read_locked(hw,
389				     hw->settings->fifo_ops.fifo_diff.addr,
390				     &fifo_status, sizeof(fifo_status));
391	if (err < 0) {
392		dev_err(hw->dev, "failed to read fifo status (err=%d)\n",
393			err);
394		return err;
395	}
396
397	if (fifo_status & cpu_to_le16(ST_LSM6DSX_FIFO_EMPTY_MASK))
398		return 0;
399
400	if (!pattern_len)
401		pattern_len = ST_LSM6DSX_SAMPLE_SIZE;
402
403	fifo_len = (le16_to_cpu(fifo_status) & fifo_diff_mask) *
404		   ST_LSM6DSX_CHAN_SIZE;
405	fifo_len = (fifo_len / pattern_len) * pattern_len;
406
407	acc_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
408	gyro_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_GYRO]);
409	if (hw->iio_devs[ST_LSM6DSX_ID_EXT0])
410		ext_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_EXT0]);
411
412	for (read_len = 0; read_len < fifo_len; read_len += pattern_len) {
413		err = st_lsm6dsx_read_block(hw, ST_LSM6DSX_REG_FIFO_OUTL_ADDR,
414					    hw->buff, pattern_len,
415					    ST_LSM6DSX_MAX_WORD_LEN);
416		if (err < 0) {
417			dev_err(hw->dev,
418				"failed to read pattern from fifo (err=%d)\n",
419				err);
420			return err;
421		}
422
423		/*
424		 * Data are written to the FIFO with a specific pattern
425		 * depending on the configured ODRs. The first sequence of data
426		 * stored in FIFO contains the data of all enabled sensors
427		 * (e.g. Gx, Gy, Gz, Ax, Ay, Az, Ts), then data are repeated
428		 * depending on the value of the decimation factor set for each
429		 * sensor.
430		 *
431		 * Supposing the FIFO is storing data from gyroscope and
432		 * accelerometer at different ODRs:
433		 *   - gyroscope ODR = 208Hz, accelerometer ODR = 104Hz
434		 * Since the gyroscope ODR is twice the accelerometer one, the
435		 * following pattern is repeated every 9 samples:
436		 *   - Gx, Gy, Gz, Ax, Ay, Az, Ts, Gx, Gy, Gz, Ts, Gx, ..
437		 */
438		ext_sip = ext_sensor ? ext_sensor->sip : 0;
439		gyro_sip = gyro_sensor->sip;
440		acc_sip = acc_sensor->sip;
441		ts_sip = hw->ts_sip;
442		offset = 0;
443		sip = 0;
444
445		while (acc_sip > 0 || gyro_sip > 0 || ext_sip > 0) {
446			if (gyro_sip > 0 && !(sip % gyro_sensor->decimator)) {
447				memcpy(hw->scan[ST_LSM6DSX_ID_GYRO].channels,
448				       &hw->buff[offset],
449				       sizeof(hw->scan[ST_LSM6DSX_ID_GYRO].channels));
450				offset += sizeof(hw->scan[ST_LSM6DSX_ID_GYRO].channels);
451			}
452			if (acc_sip > 0 && !(sip % acc_sensor->decimator)) {
453				memcpy(hw->scan[ST_LSM6DSX_ID_ACC].channels,
454				       &hw->buff[offset],
455				       sizeof(hw->scan[ST_LSM6DSX_ID_ACC].channels));
456				offset += sizeof(hw->scan[ST_LSM6DSX_ID_ACC].channels);
457			}
458			if (ext_sip > 0 && !(sip % ext_sensor->decimator)) {
459				memcpy(hw->scan[ST_LSM6DSX_ID_EXT0].channels,
460				       &hw->buff[offset],
461				       sizeof(hw->scan[ST_LSM6DSX_ID_EXT0].channels));
462				offset += sizeof(hw->scan[ST_LSM6DSX_ID_EXT0].channels);
463			}
464
465			if (ts_sip-- > 0) {
466				u8 data[ST_LSM6DSX_SAMPLE_SIZE];
467
468				memcpy(data, &hw->buff[offset], sizeof(data));
469				/*
470				 * hw timestamp is 3B long and it is stored
471				 * in FIFO using 6B as 4th FIFO data set
472				 * according to this schema:
473				 * B0 = ts[15:8], B1 = ts[23:16], B3 = ts[7:0]
474				 */
475				ts = data[1] << 16 | data[0] << 8 | data[3];
476				/*
477				 * check if hw timestamp engine is going to
478				 * reset (the sensor generates an interrupt
479				 * to signal the hw timestamp will reset in
480				 * 1.638s)
481				 */
482				if (!reset_ts && ts >= 0xff0000)
483					reset_ts = true;
484				ts *= hw->ts_gain;
485
486				offset += ST_LSM6DSX_SAMPLE_SIZE;
487			}
488
489			if (gyro_sip > 0 && !(sip % gyro_sensor->decimator)) {
490				/*
491				 * We need to discards gyro samples during
492				 * filters settling time
493				 */
494				if (gyro_sensor->samples_to_discard > 0)
495					gyro_sensor->samples_to_discard--;
496				else
497					iio_push_to_buffers_with_timestamp(
498						hw->iio_devs[ST_LSM6DSX_ID_GYRO],
499						&hw->scan[ST_LSM6DSX_ID_GYRO],
500						gyro_sensor->ts_ref + ts);
501				gyro_sip--;
502			}
503			if (acc_sip > 0 && !(sip % acc_sensor->decimator)) {
504				/*
505				 * We need to discards accel samples during
506				 * filters settling time
507				 */
508				if (acc_sensor->samples_to_discard > 0)
509					acc_sensor->samples_to_discard--;
510				else
511					iio_push_to_buffers_with_timestamp(
512						hw->iio_devs[ST_LSM6DSX_ID_ACC],
513						&hw->scan[ST_LSM6DSX_ID_ACC],
514						acc_sensor->ts_ref + ts);
515				acc_sip--;
516			}
517			if (ext_sip > 0 && !(sip % ext_sensor->decimator)) {
518				iio_push_to_buffers_with_timestamp(
519					hw->iio_devs[ST_LSM6DSX_ID_EXT0],
520					&hw->scan[ST_LSM6DSX_ID_EXT0],
521					ext_sensor->ts_ref + ts);
522				ext_sip--;
523			}
524			sip++;
525		}
526	}
527
528	if (unlikely(reset_ts)) {
529		err = st_lsm6dsx_reset_hw_ts(hw);
530		if (err < 0) {
531			dev_err(hw->dev, "failed to reset hw ts (err=%d)\n",
532				err);
533			return err;
534		}
535	}
536	return read_len;
537}
538
539#define ST_LSM6DSX_INVALID_SAMPLE	0x7ffd
540static int
541st_lsm6dsx_push_tagged_data(struct st_lsm6dsx_hw *hw, u8 tag,
542			    u8 *data, s64 ts)
543{
544	s16 val = le16_to_cpu(*(__le16 *)data);
545	struct st_lsm6dsx_sensor *sensor;
546	struct iio_dev *iio_dev;
547
548	/* invalid sample during bootstrap phase */
549	if (val >= ST_LSM6DSX_INVALID_SAMPLE)
550		return -EINVAL;
551
552	/*
553	 * EXT_TAG are managed in FIFO fashion so ST_LSM6DSX_EXT0_TAG
554	 * corresponds to the first enabled channel, ST_LSM6DSX_EXT1_TAG
555	 * to the second one and ST_LSM6DSX_EXT2_TAG to the last enabled
556	 * channel
557	 */
558	switch (tag) {
559	case ST_LSM6DSX_GYRO_TAG:
560		iio_dev = hw->iio_devs[ST_LSM6DSX_ID_GYRO];
561		break;
562	case ST_LSM6DSX_ACC_TAG:
563		iio_dev = hw->iio_devs[ST_LSM6DSX_ID_ACC];
564		break;
565	case ST_LSM6DSX_EXT0_TAG:
566		if (hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT0))
567			iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT0];
568		else if (hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT1))
569			iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT1];
570		else
571			iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT2];
572		break;
573	case ST_LSM6DSX_EXT1_TAG:
574		if ((hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT0)) &&
575		    (hw->enable_mask & BIT(ST_LSM6DSX_ID_EXT1)))
576			iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT1];
577		else
578			iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT2];
579		break;
580	case ST_LSM6DSX_EXT2_TAG:
581		iio_dev = hw->iio_devs[ST_LSM6DSX_ID_EXT2];
582		break;
583	default:
584		return -EINVAL;
585	}
586
587	sensor = iio_priv(iio_dev);
588	iio_push_to_buffers_with_timestamp(iio_dev, data,
589					   ts + sensor->ts_ref);
590
591	return 0;
592}
593
594/**
595 * st_lsm6dsx_read_tagged_fifo() - tagged hw FIFO read routine
596 * @hw: Pointer to instance of struct st_lsm6dsx_hw.
597 *
598 * Read samples from the hw FIFO and push them to IIO buffers.
599 *
600 * Return: Number of bytes read from the FIFO
601 */
602int st_lsm6dsx_read_tagged_fifo(struct st_lsm6dsx_hw *hw)
603{
604	u16 pattern_len = hw->sip * ST_LSM6DSX_TAGGED_SAMPLE_SIZE;
605	u16 fifo_len, fifo_diff_mask;
606	/*
607	 * Alignment needed as this can ultimately be passed to a
608	 * call to iio_push_to_buffers_with_timestamp() which
609	 * must be passed a buffer that is aligned to 8 bytes so
610	 * as to allow insertion of a naturally aligned timestamp.
611	 */
612	u8 iio_buff[ST_LSM6DSX_IIO_BUFF_SIZE] __aligned(8);
613	u8 tag;
614	bool reset_ts = false;
615	int i, err, read_len;
616	__le16 fifo_status;
617	s64 ts = 0;
618
619	err = st_lsm6dsx_read_locked(hw,
620				     hw->settings->fifo_ops.fifo_diff.addr,
621				     &fifo_status, sizeof(fifo_status));
622	if (err < 0) {
623		dev_err(hw->dev, "failed to read fifo status (err=%d)\n",
624			err);
625		return err;
626	}
627
628	fifo_diff_mask = hw->settings->fifo_ops.fifo_diff.mask;
629	fifo_len = (le16_to_cpu(fifo_status) & fifo_diff_mask) *
630		   ST_LSM6DSX_TAGGED_SAMPLE_SIZE;
631	if (!fifo_len)
632		return 0;
633
634	if (!pattern_len)
635		pattern_len = ST_LSM6DSX_TAGGED_SAMPLE_SIZE;
636
637	for (read_len = 0; read_len < fifo_len; read_len += pattern_len) {
638		err = st_lsm6dsx_read_block(hw,
639					    ST_LSM6DSX_REG_FIFO_OUT_TAG_ADDR,
640					    hw->buff, pattern_len,
641					    ST_LSM6DSX_MAX_TAGGED_WORD_LEN);
642		if (err < 0) {
643			dev_err(hw->dev,
644				"failed to read pattern from fifo (err=%d)\n",
645				err);
646			return err;
647		}
648
649		for (i = 0; i < pattern_len;
650		     i += ST_LSM6DSX_TAGGED_SAMPLE_SIZE) {
651			memcpy(iio_buff, &hw->buff[i + ST_LSM6DSX_TAG_SIZE],
652			       ST_LSM6DSX_SAMPLE_SIZE);
653
654			tag = hw->buff[i] >> 3;
655			if (tag == ST_LSM6DSX_TS_TAG) {
656				/*
657				 * hw timestamp is 4B long and it is stored
658				 * in FIFO according to this schema:
659				 * B0 = ts[7:0], B1 = ts[15:8], B2 = ts[23:16],
660				 * B3 = ts[31:24]
661				 */
662				ts = le32_to_cpu(*((__le32 *)iio_buff));
663				/*
664				 * check if hw timestamp engine is going to
665				 * reset (the sensor generates an interrupt
666				 * to signal the hw timestamp will reset in
667				 * 1.638s)
668				 */
669				if (!reset_ts && ts >= 0xffff0000)
670					reset_ts = true;
671				ts *= hw->ts_gain;
672			} else {
673				st_lsm6dsx_push_tagged_data(hw, tag, iio_buff,
674							    ts);
675			}
676		}
677	}
678
679	if (unlikely(reset_ts)) {
680		err = st_lsm6dsx_reset_hw_ts(hw);
681		if (err < 0)
682			return err;
683	}
684	return read_len;
685}
686
687int st_lsm6dsx_flush_fifo(struct st_lsm6dsx_hw *hw)
688{
689	int err;
690
691	if (!hw->settings->fifo_ops.read_fifo)
692		return -ENOTSUPP;
693
694	mutex_lock(&hw->fifo_lock);
695
696	hw->settings->fifo_ops.read_fifo(hw);
697	err = st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_BYPASS);
698
699	mutex_unlock(&hw->fifo_lock);
700
701	return err;
702}
703
704static void
705st_lsm6dsx_update_samples_to_discard(struct st_lsm6dsx_sensor *sensor)
706{
707	const struct st_lsm6dsx_samples_to_discard *data;
708	struct st_lsm6dsx_hw *hw = sensor->hw;
709	int i;
710
711	if (sensor->id != ST_LSM6DSX_ID_GYRO &&
712	    sensor->id != ST_LSM6DSX_ID_ACC)
713		return;
714
715	/* check if drdy mask is supported in hw */
716	if (hw->settings->drdy_mask.addr)
717		return;
718
719	data = &hw->settings->samples_to_discard[sensor->id];
720	for (i = 0; i < ST_LSM6DSX_ODR_LIST_SIZE; i++) {
721		if (data->val[i].milli_hz == sensor->hwfifo_odr_mHz) {
722			sensor->samples_to_discard = data->val[i].samples;
723			return;
724		}
725	}
726}
727
728int st_lsm6dsx_update_fifo(struct st_lsm6dsx_sensor *sensor, bool enable)
729{
730	struct st_lsm6dsx_hw *hw = sensor->hw;
731	u8 fifo_mask;
732	int err;
733
734	mutex_lock(&hw->conf_lock);
735
736	if (enable)
737		fifo_mask = hw->fifo_mask | BIT(sensor->id);
738	else
739		fifo_mask = hw->fifo_mask & ~BIT(sensor->id);
740
741	if (hw->fifo_mask) {
742		err = st_lsm6dsx_flush_fifo(hw);
743		if (err < 0)
744			goto out;
745	}
746
747	if (enable)
748		st_lsm6dsx_update_samples_to_discard(sensor);
749
750	err = st_lsm6dsx_device_set_enable(sensor, enable);
751	if (err < 0)
752		goto out;
753
754	err = st_lsm6dsx_set_fifo_odr(sensor, enable);
755	if (err < 0)
756		goto out;
757
758	err = st_lsm6dsx_update_decimators(hw);
759	if (err < 0)
760		goto out;
761
762	err = st_lsm6dsx_update_watermark(sensor, sensor->watermark);
763	if (err < 0)
764		goto out;
765
766	if (fifo_mask) {
767		err = st_lsm6dsx_resume_fifo(hw);
768		if (err < 0)
769			goto out;
770	}
771
772	hw->fifo_mask = fifo_mask;
773
774out:
775	mutex_unlock(&hw->conf_lock);
776
777	return err;
778}
779
780static int st_lsm6dsx_buffer_preenable(struct iio_dev *iio_dev)
781{
782	struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
783	struct st_lsm6dsx_hw *hw = sensor->hw;
784
785	if (!hw->settings->fifo_ops.update_fifo)
786		return -ENOTSUPP;
787
788	return hw->settings->fifo_ops.update_fifo(sensor, true);
789}
790
791static int st_lsm6dsx_buffer_postdisable(struct iio_dev *iio_dev)
792{
793	struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
794	struct st_lsm6dsx_hw *hw = sensor->hw;
795
796	if (!hw->settings->fifo_ops.update_fifo)
797		return -ENOTSUPP;
798
799	return hw->settings->fifo_ops.update_fifo(sensor, false);
800}
801
802static const struct iio_buffer_setup_ops st_lsm6dsx_buffer_ops = {
803	.preenable = st_lsm6dsx_buffer_preenable,
804	.postdisable = st_lsm6dsx_buffer_postdisable,
805};
806
807static ssize_t st_lsm6dsx_hwfifo_odr_show(struct device *dev,
808					  struct device_attribute *attr, char *buf)
809{
810	struct st_lsm6dsx_sensor *sensor = iio_priv(dev_to_iio_dev(dev));
811
812	return sysfs_emit(buf, "%d.%03d\n", sensor->hwfifo_odr_mHz / 1000,
813			  sensor->hwfifo_odr_mHz % 1000);
814}
815
816static ssize_t st_lsm6dsx_hwfifo_odr_store(struct device *dev,
817					   struct device_attribute *attr,
818					   const char *buf, size_t len)
819{
820	struct iio_dev *iio_dev = dev_to_iio_dev(dev);
821	struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
822	int integer, milli;
823	int ret;
824	u32 hwfifo_odr;
825	u8 data;
826
827	if (!iio_device_claim_direct(iio_dev))
828		return -EBUSY;
829
830	ret = iio_str_to_fixpoint(buf, 100, &integer, &milli);
831	if (ret)
832		goto out;
833
834	hwfifo_odr = integer * 1000 + milli;
835	ret = st_lsm6dsx_check_odr(sensor, hwfifo_odr, &data);
836	if (ret < 0)
837		goto out;
838
839	hwfifo_odr = ret;
840
841	/* the batch data rate must not exceed the sensor output data rate */
842	if (hwfifo_odr <= sensor->odr)
843		sensor->hwfifo_odr_mHz = hwfifo_odr;
844	else
845		ret = -EINVAL;
846
847out:
848	iio_device_release_direct(iio_dev);
849
850	return ret < 0 ? ret : len;
851}
852
853static IIO_DEV_ATTR_SAMP_FREQ(0664, st_lsm6dsx_hwfifo_odr_show, st_lsm6dsx_hwfifo_odr_store);
854
855static const struct iio_dev_attr *st_lsm6dsx_buffer_attrs[] = {
856	&iio_dev_attr_sampling_frequency,
857	NULL
858};
859
860int st_lsm6dsx_fifo_setup(struct st_lsm6dsx_hw *hw)
861{
862	int i, ret;
863
864	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
865		const struct iio_dev_attr **attrs;
866
867		if (!hw->iio_devs[i])
868			continue;
869
870		/*
871		 * For the accelerometer, allow setting FIFO sampling frequency
872		 * values different from the sensor sampling frequency, which
873		 * may be needed to keep FIFO data rate low while sampling
874		 * acceleration data at high rates for accurate event detection.
875		 */
876		attrs = i == ST_LSM6DSX_ID_ACC ? st_lsm6dsx_buffer_attrs : NULL;
877		ret = devm_iio_kfifo_buffer_setup_ext(hw->dev, hw->iio_devs[i],
878						      &st_lsm6dsx_buffer_ops,
879						      attrs);
880		if (ret)
881			return ret;
882	}
883
884	return 0;
885}