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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012 Invensense, Inc.
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/sysfs.h>
#include <linux/jiffies.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/poll.h>
#include <linux/math64.h>
#include <linux/iio/common/inv_sensors_timestamp.h>
#include "inv_mpu_iio.h"
static int inv_reset_fifo(struct iio_dev *indio_dev)
{
int result;
struct inv_mpu6050_state *st = iio_priv(indio_dev);
/* disable fifo and reenable it */
inv_mpu6050_prepare_fifo(st, false);
result = inv_mpu6050_prepare_fifo(st, true);
if (result)
goto reset_fifo_fail;
return 0;
reset_fifo_fail:
dev_err(regmap_get_device(st->map), "reset fifo failed %d\n", result);
return regmap_update_bits(st->map, st->reg->int_enable,
INV_MPU6050_BIT_DATA_RDY_EN, INV_MPU6050_BIT_DATA_RDY_EN);
}
/*
* inv_mpu6050_read_fifo() - Transfer data from hardware FIFO to KFIFO.
*/
irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct inv_mpu6050_state *st = iio_priv(indio_dev);
size_t bytes_per_datum;
int result;
u16 fifo_count;
u32 fifo_period;
s64 timestamp;
u8 data[INV_MPU6050_OUTPUT_DATA_SIZE];
size_t i, nb;
mutex_lock(&st->lock);
if (!(st->chip_config.accl_fifo_enable |
st->chip_config.gyro_fifo_enable |
st->chip_config.magn_fifo_enable))
goto end_session;
bytes_per_datum = 0;
if (st->chip_config.accl_fifo_enable)
bytes_per_datum += INV_MPU6050_BYTES_PER_3AXIS_SENSOR;
if (st->chip_config.gyro_fifo_enable)
bytes_per_datum += INV_MPU6050_BYTES_PER_3AXIS_SENSOR;
if (st->chip_config.temp_fifo_enable)
bytes_per_datum += INV_MPU6050_BYTES_PER_TEMP_SENSOR;
if (st->chip_config.magn_fifo_enable)
bytes_per_datum += INV_MPU9X50_BYTES_MAGN;
/*
* read fifo_count register to know how many bytes are inside the FIFO
* right now
*/
result = regmap_bulk_read(st->map, st->reg->fifo_count_h,
st->data, INV_MPU6050_FIFO_COUNT_BYTE);
if (result)
goto end_session;
fifo_count = be16_to_cpup((__be16 *)&st->data[0]);
/*
* Handle fifo overflow by resetting fifo.
* Reset if there is only 3 data set free remaining to mitigate
* possible delay between reading fifo count and fifo data.
*/
nb = 3 * bytes_per_datum;
if (fifo_count >= st->hw->fifo_size - nb) {
dev_warn(regmap_get_device(st->map), "fifo overflow reset\n");
goto flush_fifo;
}
/* compute and process only all complete datum */
nb = fifo_count / bytes_per_datum;
fifo_count = nb * bytes_per_datum;
if (nb == 0)
goto end_session;
/* Each FIFO data contains all sensors, so same number for FIFO and sensor data */
fifo_period = NSEC_PER_SEC / INV_MPU6050_DIVIDER_TO_FIFO_RATE(st->chip_config.divider);
inv_sensors_timestamp_interrupt(&st->timestamp, 1, pf->timestamp);
inv_sensors_timestamp_apply_odr(&st->timestamp, fifo_period, 1, 0);
/* clear internal data buffer for avoiding kernel data leak */
memset(data, 0, sizeof(data));
/* read all data once and process every samples */
result = regmap_noinc_read(st->map, st->reg->fifo_r_w, st->data, fifo_count);
if (result)
goto flush_fifo;
for (i = 0; i < nb; ++i) {
/* skip first samples if needed */
if (st->skip_samples) {
st->skip_samples--;
continue;
}
memcpy(data, &st->data[i * bytes_per_datum], bytes_per_datum);
timestamp = inv_sensors_timestamp_pop(&st->timestamp);
iio_push_to_buffers_with_timestamp(indio_dev, data, timestamp);
}
end_session:
mutex_unlock(&st->lock);
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
flush_fifo:
/* Flush HW and SW FIFOs. */
inv_reset_fifo(indio_dev);
mutex_unlock(&st->lock);
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
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