diff options
Diffstat (limited to 'drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c')
| -rw-r--r-- | drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c | 601 |
1 files changed, 601 insertions, 0 deletions
diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c new file mode 100644 index 000000000000..99576b2c171f --- /dev/null +++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c @@ -0,0 +1,601 @@ +// 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/iio.h> +#include <linux/iio/buffer.h> + +#include "inv_icm42600.h" +#include "inv_icm42600_timestamp.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); + + pm_runtime_get_sync(dev); + + 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_timestamp *ts; + 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; + ts = iio_priv(st->indio_gyro); + } else if (indio_dev == st->indio_accel) { + sensor = INV_ICM42600_SENSOR_ACCEL; + watermark = &st->fifo.watermark.accel; + ts = iio_priv(st->indio_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); + + inv_icm42600_timestamp_reset(ts); + +out_unlock: + mutex_unlock(&st->lock); + + /* sleep maximum required time */ + if (sleep_sensor > sleep_temp) + sleep = sleep_sensor; + else + sleep = 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, ×tamp, &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_icm42600_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_icm42600_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_icm42600_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_icm42600_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_icm42600_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_icm42600_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); +} |