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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2020 Invensense, Inc.
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/delay.h>
#include <linux/iio/buffer.h>
#include <linux/iio/common/inv_sensors_timestamp.h>
#include <linux/iio/iio.h>
#include "inv_icm42600.h"
#include "inv_icm42600_buffer.h"
/* FIFO header: 1 byte */
#define INV_ICM42600_FIFO_HEADER_MSG BIT(7)
#define INV_ICM42600_FIFO_HEADER_ACCEL BIT(6)
#define INV_ICM42600_FIFO_HEADER_GYRO BIT(5)
#define INV_ICM42600_FIFO_HEADER_TMST_FSYNC GENMASK(3, 2)
#define INV_ICM42600_FIFO_HEADER_ODR_ACCEL BIT(1)
#define INV_ICM42600_FIFO_HEADER_ODR_GYRO BIT(0)
struct inv_icm42600_fifo_1sensor_packet {
uint8_t header;
struct inv_icm42600_fifo_sensor_data data;
int8_t temp;
} __packed;
#define INV_ICM42600_FIFO_1SENSOR_PACKET_SIZE 8
struct inv_icm42600_fifo_2sensors_packet {
uint8_t header;
struct inv_icm42600_fifo_sensor_data accel;
struct inv_icm42600_fifo_sensor_data gyro;
int8_t temp;
__be16 timestamp;
} __packed;
#define INV_ICM42600_FIFO_2SENSORS_PACKET_SIZE 16
ssize_t inv_icm42600_fifo_decode_packet(const void *packet, const void **accel,
const void **gyro, const int8_t **temp,
const void **timestamp, unsigned int *odr)
{
const struct inv_icm42600_fifo_1sensor_packet *pack1 = packet;
const struct inv_icm42600_fifo_2sensors_packet *pack2 = packet;
uint8_t header = *((const uint8_t *)packet);
/* FIFO empty */
if (header & INV_ICM42600_FIFO_HEADER_MSG) {
*accel = NULL;
*gyro = NULL;
*temp = NULL;
*timestamp = NULL;
*odr = 0;
return 0;
}
/* handle odr flags */
*odr = 0;
if (header & INV_ICM42600_FIFO_HEADER_ODR_GYRO)
*odr |= INV_ICM42600_SENSOR_GYRO;
if (header & INV_ICM42600_FIFO_HEADER_ODR_ACCEL)
*odr |= INV_ICM42600_SENSOR_ACCEL;
/* accel + gyro */
if ((header & INV_ICM42600_FIFO_HEADER_ACCEL) &&
(header & INV_ICM42600_FIFO_HEADER_GYRO)) {
*accel = &pack2->accel;
*gyro = &pack2->gyro;
*temp = &pack2->temp;
*timestamp = &pack2->timestamp;
return INV_ICM42600_FIFO_2SENSORS_PACKET_SIZE;
}
/* accel only */
if (header & INV_ICM42600_FIFO_HEADER_ACCEL) {
*accel = &pack1->data;
*gyro = NULL;
*temp = &pack1->temp;
*timestamp = NULL;
return INV_ICM42600_FIFO_1SENSOR_PACKET_SIZE;
}
/* gyro only */
if (header & INV_ICM42600_FIFO_HEADER_GYRO) {
*accel = NULL;
*gyro = &pack1->data;
*temp = &pack1->temp;
*timestamp = NULL;
return INV_ICM42600_FIFO_1SENSOR_PACKET_SIZE;
}
/* invalid packet if here */
return -EINVAL;
}
void inv_icm42600_buffer_update_fifo_period(struct inv_icm42600_state *st)
{
uint32_t period_gyro, period_accel, period;
if (st->fifo.en & INV_ICM42600_SENSOR_GYRO)
period_gyro = inv_icm42600_odr_to_period(st->conf.gyro.odr);
else
period_gyro = U32_MAX;
if (st->fifo.en & INV_ICM42600_SENSOR_ACCEL)
period_accel = inv_icm42600_odr_to_period(st->conf.accel.odr);
else
period_accel = U32_MAX;
if (period_gyro <= period_accel)
period = period_gyro;
else
period = period_accel;
st->fifo.period = period;
}
int inv_icm42600_buffer_set_fifo_en(struct inv_icm42600_state *st,
unsigned int fifo_en)
{
unsigned int mask, val;
int ret;
/* update only FIFO EN bits */
mask = INV_ICM42600_FIFO_CONFIG1_TMST_FSYNC_EN |
INV_ICM42600_FIFO_CONFIG1_TEMP_EN |
INV_ICM42600_FIFO_CONFIG1_GYRO_EN |
INV_ICM42600_FIFO_CONFIG1_ACCEL_EN;
val = 0;
if (fifo_en & INV_ICM42600_SENSOR_GYRO)
val |= INV_ICM42600_FIFO_CONFIG1_GYRO_EN;
if (fifo_en & INV_ICM42600_SENSOR_ACCEL)
val |= INV_ICM42600_FIFO_CONFIG1_ACCEL_EN;
if (fifo_en & INV_ICM42600_SENSOR_TEMP)
val |= INV_ICM42600_FIFO_CONFIG1_TEMP_EN;
ret = regmap_update_bits(st->map, INV_ICM42600_REG_FIFO_CONFIG1, mask, val);
if (ret)
return ret;
st->fifo.en = fifo_en;
inv_icm42600_buffer_update_fifo_period(st);
return 0;
}
static size_t inv_icm42600_get_packet_size(unsigned int fifo_en)
{
size_t packet_size;
if ((fifo_en & INV_ICM42600_SENSOR_GYRO) &&
(fifo_en & INV_ICM42600_SENSOR_ACCEL))
packet_size = INV_ICM42600_FIFO_2SENSORS_PACKET_SIZE;
else
packet_size = INV_ICM42600_FIFO_1SENSOR_PACKET_SIZE;
return packet_size;
}
static unsigned int inv_icm42600_wm_truncate(unsigned int watermark,
size_t packet_size)
{
size_t wm_size;
unsigned int wm;
wm_size = watermark * packet_size;
if (wm_size > INV_ICM42600_FIFO_WATERMARK_MAX)
wm_size = INV_ICM42600_FIFO_WATERMARK_MAX;
wm = wm_size / packet_size;
return wm;
}
/**
* inv_icm42600_buffer_update_watermark - update watermark FIFO threshold
* @st: driver internal state
*
* Returns 0 on success, a negative error code otherwise.
*
* FIFO watermark threshold is computed based on the required watermark values
* set for gyro and accel sensors. Since watermark is all about acceptable data
* latency, use the smallest setting between the 2. It means choosing the
* smallest latency but this is not as simple as choosing the smallest watermark
* value. Latency depends on watermark and ODR. It requires several steps:
* 1) compute gyro and accel latencies and choose the smallest value.
* 2) adapt the choosen latency so that it is a multiple of both gyro and accel
* ones. Otherwise it is possible that you don't meet a requirement. (for
* example with gyro @100Hz wm 4 and accel @100Hz with wm 6, choosing the
* value of 4 will not meet accel latency requirement because 6 is not a
* multiple of 4. You need to use the value 2.)
* 3) Since all periods are multiple of each others, watermark is computed by
* dividing this computed latency by the smallest period, which corresponds
* to the FIFO frequency. Beware that this is only true because we are not
* using 500Hz frequency which is not a multiple of the others.
*/
int inv_icm42600_buffer_update_watermark(struct inv_icm42600_state *st)
{
size_t packet_size, wm_size;
unsigned int wm_gyro, wm_accel, watermark;
uint32_t period_gyro, period_accel, period;
uint32_t latency_gyro, latency_accel, latency;
bool restore;
__le16 raw_wm;
int ret;
packet_size = inv_icm42600_get_packet_size(st->fifo.en);
/* compute sensors latency, depending on sensor watermark and odr */
wm_gyro = inv_icm42600_wm_truncate(st->fifo.watermark.gyro, packet_size);
wm_accel = inv_icm42600_wm_truncate(st->fifo.watermark.accel, packet_size);
/* use us for odr to avoid overflow using 32 bits values */
period_gyro = inv_icm42600_odr_to_period(st->conf.gyro.odr) / 1000UL;
period_accel = inv_icm42600_odr_to_period(st->conf.accel.odr) / 1000UL;
latency_gyro = period_gyro * wm_gyro;
latency_accel = period_accel * wm_accel;
/* 0 value for watermark means that the sensor is turned off */
if (latency_gyro == 0) {
watermark = wm_accel;
} else if (latency_accel == 0) {
watermark = wm_gyro;
} else {
/* compute the smallest latency that is a multiple of both */
if (latency_gyro <= latency_accel)
latency = latency_gyro - (latency_accel % latency_gyro);
else
latency = latency_accel - (latency_gyro % latency_accel);
/* use the shortest period */
if (period_gyro <= period_accel)
period = period_gyro;
else
period = period_accel;
/* all this works because periods are multiple of each others */
watermark = latency / period;
if (watermark < 1)
watermark = 1;
}
/* compute watermark value in bytes */
wm_size = watermark * packet_size;
/* changing FIFO watermark requires to turn off watermark interrupt */
ret = regmap_update_bits_check(st->map, INV_ICM42600_REG_INT_SOURCE0,
INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN,
0, &restore);
if (ret)
return ret;
raw_wm = INV_ICM42600_FIFO_WATERMARK_VAL(wm_size);
memcpy(st->buffer, &raw_wm, sizeof(raw_wm));
ret = regmap_bulk_write(st->map, INV_ICM42600_REG_FIFO_WATERMARK,
st->buffer, sizeof(raw_wm));
if (ret)
return ret;
/* restore watermark interrupt */
if (restore) {
ret = regmap_update_bits(st->map, INV_ICM42600_REG_INT_SOURCE0,
INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN,
INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN);
if (ret)
return ret;
}
return 0;
}
static int inv_icm42600_buffer_preenable(struct iio_dev *indio_dev)
{
struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
struct device *dev = regmap_get_device(st->map);
struct inv_sensors_timestamp *ts = iio_priv(indio_dev);
pm_runtime_get_sync(dev);
mutex_lock(&st->lock);
inv_sensors_timestamp_reset(ts);
mutex_unlock(&st->lock);
return 0;
}
/*
* update_scan_mode callback is turning sensors on and setting data FIFO enable
* bits.
*/
static int inv_icm42600_buffer_postenable(struct iio_dev *indio_dev)
{
struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
int ret;
mutex_lock(&st->lock);
/* exit if FIFO is already on */
if (st->fifo.on) {
ret = 0;
goto out_on;
}
/* set FIFO threshold interrupt */
ret = regmap_update_bits(st->map, INV_ICM42600_REG_INT_SOURCE0,
INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN,
INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN);
if (ret)
goto out_unlock;
/* flush FIFO data */
ret = regmap_write(st->map, INV_ICM42600_REG_SIGNAL_PATH_RESET,
INV_ICM42600_SIGNAL_PATH_RESET_FIFO_FLUSH);
if (ret)
goto out_unlock;
/* set FIFO in streaming mode */
ret = regmap_write(st->map, INV_ICM42600_REG_FIFO_CONFIG,
INV_ICM42600_FIFO_CONFIG_STREAM);
if (ret)
goto out_unlock;
/* workaround: first read of FIFO count after reset is always 0 */
ret = regmap_bulk_read(st->map, INV_ICM42600_REG_FIFO_COUNT, st->buffer, 2);
if (ret)
goto out_unlock;
out_on:
/* increase FIFO on counter */
st->fifo.on++;
out_unlock:
mutex_unlock(&st->lock);
return ret;
}
static int inv_icm42600_buffer_predisable(struct iio_dev *indio_dev)
{
struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
int ret;
mutex_lock(&st->lock);
/* exit if there are several sensors using the FIFO */
if (st->fifo.on > 1) {
ret = 0;
goto out_off;
}
/* set FIFO in bypass mode */
ret = regmap_write(st->map, INV_ICM42600_REG_FIFO_CONFIG,
INV_ICM42600_FIFO_CONFIG_BYPASS);
if (ret)
goto out_unlock;
/* flush FIFO data */
ret = regmap_write(st->map, INV_ICM42600_REG_SIGNAL_PATH_RESET,
INV_ICM42600_SIGNAL_PATH_RESET_FIFO_FLUSH);
if (ret)
goto out_unlock;
/* disable FIFO threshold interrupt */
ret = regmap_update_bits(st->map, INV_ICM42600_REG_INT_SOURCE0,
INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN, 0);
if (ret)
goto out_unlock;
out_off:
/* decrease FIFO on counter */
st->fifo.on--;
out_unlock:
mutex_unlock(&st->lock);
return ret;
}
static int inv_icm42600_buffer_postdisable(struct iio_dev *indio_dev)
{
struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
struct device *dev = regmap_get_device(st->map);
unsigned int sensor;
unsigned int *watermark;
struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
unsigned int sleep_temp = 0;
unsigned int sleep_sensor = 0;
unsigned int sleep;
int ret;
if (indio_dev == st->indio_gyro) {
sensor = INV_ICM42600_SENSOR_GYRO;
watermark = &st->fifo.watermark.gyro;
} else if (indio_dev == st->indio_accel) {
sensor = INV_ICM42600_SENSOR_ACCEL;
watermark = &st->fifo.watermark.accel;
} else {
return -EINVAL;
}
mutex_lock(&st->lock);
ret = inv_icm42600_buffer_set_fifo_en(st, st->fifo.en & ~sensor);
if (ret)
goto out_unlock;
*watermark = 0;
ret = inv_icm42600_buffer_update_watermark(st);
if (ret)
goto out_unlock;
conf.mode = INV_ICM42600_SENSOR_MODE_OFF;
if (sensor == INV_ICM42600_SENSOR_GYRO)
ret = inv_icm42600_set_gyro_conf(st, &conf, &sleep_sensor);
else
ret = inv_icm42600_set_accel_conf(st, &conf, &sleep_sensor);
if (ret)
goto out_unlock;
/* if FIFO is off, turn temperature off */
if (!st->fifo.on)
ret = inv_icm42600_set_temp_conf(st, false, &sleep_temp);
out_unlock:
mutex_unlock(&st->lock);
/* sleep maximum required time */
sleep = max(sleep_sensor, sleep_temp);
if (sleep)
msleep(sleep);
pm_runtime_mark_last_busy(dev);
pm_runtime_put_autosuspend(dev);
return ret;
}
const struct iio_buffer_setup_ops inv_icm42600_buffer_ops = {
.preenable = inv_icm42600_buffer_preenable,
.postenable = inv_icm42600_buffer_postenable,
.predisable = inv_icm42600_buffer_predisable,
.postdisable = inv_icm42600_buffer_postdisable,
};
int inv_icm42600_buffer_fifo_read(struct inv_icm42600_state *st,
unsigned int max)
{
size_t max_count;
__be16 *raw_fifo_count;
ssize_t i, size;
const void *accel, *gyro, *timestamp;
const int8_t *temp;
unsigned int odr;
int ret;
/* reset all samples counters */
st->fifo.count = 0;
st->fifo.nb.gyro = 0;
st->fifo.nb.accel = 0;
st->fifo.nb.total = 0;
/* compute maximum FIFO read size */
if (max == 0)
max_count = sizeof(st->fifo.data);
else
max_count = max * inv_icm42600_get_packet_size(st->fifo.en);
/* read FIFO count value */
raw_fifo_count = (__be16 *)st->buffer;
ret = regmap_bulk_read(st->map, INV_ICM42600_REG_FIFO_COUNT,
raw_fifo_count, sizeof(*raw_fifo_count));
if (ret)
return ret;
st->fifo.count = be16_to_cpup(raw_fifo_count);
/* check and clamp FIFO count value */
if (st->fifo.count == 0)
return 0;
if (st->fifo.count > max_count)
st->fifo.count = max_count;
/* read all FIFO data in internal buffer */
ret = regmap_noinc_read(st->map, INV_ICM42600_REG_FIFO_DATA,
st->fifo.data, st->fifo.count);
if (ret)
return ret;
/* compute number of samples for each sensor */
for (i = 0; i < st->fifo.count; i += size) {
size = inv_icm42600_fifo_decode_packet(&st->fifo.data[i],
&accel, &gyro, &temp, &timestamp, &odr);
if (size <= 0)
break;
if (gyro != NULL && inv_icm42600_fifo_is_data_valid(gyro))
st->fifo.nb.gyro++;
if (accel != NULL && inv_icm42600_fifo_is_data_valid(accel))
st->fifo.nb.accel++;
st->fifo.nb.total++;
}
return 0;
}
int inv_icm42600_buffer_fifo_parse(struct inv_icm42600_state *st)
{
struct inv_sensors_timestamp *ts;
int ret;
if (st->fifo.nb.total == 0)
return 0;
/* handle gyroscope timestamp and FIFO data parsing */
ts = iio_priv(st->indio_gyro);
inv_sensors_timestamp_interrupt(ts, st->fifo.period, st->fifo.nb.total,
st->fifo.nb.gyro, st->timestamp.gyro);
if (st->fifo.nb.gyro > 0) {
ret = inv_icm42600_gyro_parse_fifo(st->indio_gyro);
if (ret)
return ret;
}
/* handle accelerometer timestamp and FIFO data parsing */
ts = iio_priv(st->indio_accel);
inv_sensors_timestamp_interrupt(ts, st->fifo.period, st->fifo.nb.total,
st->fifo.nb.accel, st->timestamp.accel);
if (st->fifo.nb.accel > 0) {
ret = inv_icm42600_accel_parse_fifo(st->indio_accel);
if (ret)
return ret;
}
return 0;
}
int inv_icm42600_buffer_hwfifo_flush(struct inv_icm42600_state *st,
unsigned int count)
{
struct inv_sensors_timestamp *ts;
int64_t gyro_ts, accel_ts;
int ret;
gyro_ts = iio_get_time_ns(st->indio_gyro);
accel_ts = iio_get_time_ns(st->indio_accel);
ret = inv_icm42600_buffer_fifo_read(st, count);
if (ret)
return ret;
if (st->fifo.nb.total == 0)
return 0;
if (st->fifo.nb.gyro > 0) {
ts = iio_priv(st->indio_gyro);
inv_sensors_timestamp_interrupt(ts, st->fifo.period,
st->fifo.nb.total, st->fifo.nb.gyro,
gyro_ts);
ret = inv_icm42600_gyro_parse_fifo(st->indio_gyro);
if (ret)
return ret;
}
if (st->fifo.nb.accel > 0) {
ts = iio_priv(st->indio_accel);
inv_sensors_timestamp_interrupt(ts, st->fifo.period,
st->fifo.nb.total, st->fifo.nb.accel,
accel_ts);
ret = inv_icm42600_accel_parse_fifo(st->indio_accel);
if (ret)
return ret;
}
return 0;
}
int inv_icm42600_buffer_init(struct inv_icm42600_state *st)
{
unsigned int val;
int ret;
/*
* Default FIFO configuration (bits 7 to 5)
* - use invalid value
* - FIFO count in bytes
* - FIFO count in big endian
*/
val = INV_ICM42600_INTF_CONFIG0_FIFO_COUNT_ENDIAN;
ret = regmap_update_bits(st->map, INV_ICM42600_REG_INTF_CONFIG0,
GENMASK(7, 5), val);
if (ret)
return ret;
/*
* Enable FIFO partial read and continuous watermark interrupt.
* Disable all FIFO EN bits.
*/
val = INV_ICM42600_FIFO_CONFIG1_RESUME_PARTIAL_RD |
INV_ICM42600_FIFO_CONFIG1_WM_GT_TH;
return regmap_update_bits(st->map, INV_ICM42600_REG_FIFO_CONFIG1,
GENMASK(6, 5) | GENMASK(3, 0), val);
}