Re: [PATCH 09/12] iio: imu: inv_icm42600: add buffer support in iio devices

Jean-Baptiste Maneyrol
2020-05-18T15:34:04Z

Hi Jonathan,

no problem with the comments.

fifo_decode_packet will move to source code,

For the following sleep comment:
> +     if (sleep_gyro > sleep_temp)
> +             sleep = sleep_gyro;
> +     else
> +             sleep = sleep_temp;
> +     if (sleep)
> +             msleep(sleep);

if (sleep_gyro > sleep_temp)
msleep(sleep_gyro);
else
msleep(sleep_temp);

I am using an intermediate local variable to avoid a call to msleep(0) which is in fact sleeping for real for 1 jiffies as far as I understand. So is it OK to keep it as is?

Thanks,
JB

From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>

Sent: Friday, May 8, 2020 16:19

To: Jean-Baptiste Maneyrol <JManeyrol@invensense.com>

Cc: jic23@kernel.org <jic23@kernel.org>; robh+dt@kernel.org <robh+dt@kernel.org>; robh@kernel.org <robh@kernel.org>; mchehab+huawei@kernel.org <mchehab+huawei@kernel.org>; davem@davemloft.net <davem@davemloft.net>; gregkh@linuxfoundation.org <gregkh@linuxfoundation.org>;
linux-iio@vger.kernel.org <linux-iio@vger.kernel.org>; devicetree@vger.kernel.org <devicetree@vger.kernel.org>; linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>

Subject: Re: [PATCH 09/12] iio: imu: inv_icm42600: add buffer support in iio devices

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On Thu, 7 May 2020 16:42:19 +0200

Jean-Baptiste Maneyrol <jmaneyrol@invensense.com> wrote:

> Use triggered buffer by parsing FIFO data read in device trigger.

> Support hwfifo watermark by multiplexing gyro and accel settings.

> Support hwfifo flush.

>

> Simply use interrupt timestamp first.

>

> Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>

> ---

>  drivers/iio/imu/inv_icm42600/Kconfig          |   3 +-

>  drivers/iio/imu/inv_icm42600/Makefile         |   1 +

>  drivers/iio/imu/inv_icm42600/inv_icm42600.h   |   8 +

>  .../iio/imu/inv_icm42600/inv_icm42600_accel.c | 183 +++++++++

>  .../imu/inv_icm42600/inv_icm42600_buffer.c    | 353 ++++++++++++++++++

>  .../imu/inv_icm42600/inv_icm42600_buffer.h    | 162 ++++++++

>  .../iio/imu/inv_icm42600/inv_icm42600_core.c  |  23 ++

>  .../iio/imu/inv_icm42600/inv_icm42600_gyro.c  | 183 +++++++++

>  .../imu/inv_icm42600/inv_icm42600_trigger.c   |  15 +-

>  9 files changed, 928 insertions(+), 3 deletions(-)

>  create mode 100644 drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c

>  create mode 100644 drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.h

>

> diff --git a/drivers/iio/imu/inv_icm42600/Kconfig b/drivers/iio/imu/inv_icm42600/Kconfig

> index 7b3eaeb2aa4a..8c0969319c49 100644

> --- a/drivers/iio/imu/inv_icm42600/Kconfig

> +++ b/drivers/iio/imu/inv_icm42600/Kconfig

> @@ -2,7 +2,8 @@

>

>  config INV_ICM42600

>        tristate

> -     select IIO_TRIGGER

> +     select IIO_BUFFER

> +     select IIO_TRIGGERED_BUFFER

>

>  config INV_ICM42600_I2C

>        tristate "InvenSense ICM-426xx I2C driver"

> diff --git a/drivers/iio/imu/inv_icm42600/Makefile b/drivers/iio/imu/inv_icm42600/Makefile

> index e1f2aacbe888..d6732118010c 100644

> --- a/drivers/iio/imu/inv_icm42600/Makefile

> +++ b/drivers/iio/imu/inv_icm42600/Makefile

> @@ -6,6 +6,7 @@ inv-icm42600-y += inv_icm42600_gyro.o

>  inv-icm42600-y += inv_icm42600_accel.o

>  inv-icm42600-y += inv_icm42600_temp.o

>  inv-icm42600-y += inv_icm42600_trigger.o

> +inv-icm42600-y += inv_icm42600_buffer.o

>

>  obj-$(CONFIG_INV_ICM42600_I2C) += inv-icm42600-i2c.o

>  inv-icm42600-i2c-y += inv_icm42600_i2c.o

> diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600.h b/drivers/iio/imu/inv_icm42600/inv_icm42600.h

> index 175c1f67faee..947ca4dd245b 100644

> --- a/drivers/iio/imu/inv_icm42600/inv_icm42600.h

> +++ b/drivers/iio/imu/inv_icm42600/inv_icm42600.h

> @@ -15,6 +15,8 @@

>  #include <linux/iio/iio.h>

>  #include <linux/iio/trigger.h>

>

> +#include "inv_icm42600_buffer.h"

> +

>  enum inv_icm42600_chip {

>        INV_CHIP_ICM42600,

>        INV_CHIP_ICM42602,

> @@ -124,6 +126,7 @@ struct inv_icm42600_suspended {

>   *  @indio_gyro:     gyroscope IIO device.

>   *  @indio_accel:    accelerometer IIO device.

>   *  @trigger:                device internal interrupt trigger

> + *  @fifo:           FIFO management structure.

>   */

>  struct inv_icm42600_state {

>        struct mutex lock;

> @@ -138,6 +141,7 @@ struct inv_icm42600_state {

>        struct iio_dev *indio_gyro;

>        struct iio_dev *indio_accel;

>        struct iio_trigger *trigger;

> +     struct inv_icm42600_fifo fifo;

>  };

>

>  /* Virtual register addresses: @bank on MSB (4 upper bits), @address on LSB */

> @@ -378,8 +382,12 @@ int inv_icm42600_core_probe(struct regmap *regmap, int chip, int irq,

>

>  int inv_icm42600_gyro_init(struct inv_icm42600_state *st);

>

> +int inv_icm42600_gyro_parse_fifo(struct iio_dev *indio_dev, int64_t ts);

> +

>  int inv_icm42600_accel_init(struct inv_icm42600_state *st);

>

> +int inv_icm42600_accel_parse_fifo(struct iio_dev *indio_dev, int64_t ts);

> +

>  int inv_icm42600_trigger_init(struct inv_icm42600_state *st, int irq,

>                              int irq_type);

>

> diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c

> index 74dac5f283d4..4206be54d057 100644

> --- a/drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c

> +++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c

> @@ -10,9 +10,13 @@

>  #include <linux/regmap.h>

>  #include <linux/delay.h>

>  #include <linux/iio/iio.h>

> +#include <linux/iio/buffer.h>

> +#include <linux/iio/triggered_buffer.h>

> +#include <linux/iio/trigger_consumer.h>

>

>  #include "inv_icm42600.h"

>  #include "inv_icm42600_temp.h"

> +#include "inv_icm42600_buffer.h"

>

>  #define INV_ICM42600_ACCEL_CHAN(_modifier, _index, _ext_info)                \

>        {                                                               \

> @@ -46,6 +50,7 @@ enum inv_icm42600_accel_scan {

>        INV_ICM42600_ACCEL_SCAN_Y,

>        INV_ICM42600_ACCEL_SCAN_Z,

>        INV_ICM42600_ACCEL_SCAN_TEMP,

> +     INV_ICM42600_ACCEL_SCAN_TIMESTAMP,

>  };

>

>  static const struct iio_chan_spec_ext_info inv_icm42600_accel_ext_infos[] = {

> @@ -61,8 +66,100 @@ static const struct iio_chan_spec inv_icm42600_accel_channels[] = {

>        INV_ICM42600_ACCEL_CHAN(IIO_MOD_Z, INV_ICM42600_ACCEL_SCAN_Z,

>                                inv_icm42600_accel_ext_infos),

>        INV_ICM42600_TEMP_CHAN(INV_ICM42600_ACCEL_SCAN_TEMP),

> +     IIO_CHAN_SOFT_TIMESTAMP(INV_ICM42600_ACCEL_SCAN_TIMESTAMP),

>  };

>

> +/* IIO buffer data */

> +struct inv_icm42600_accel_buffer {

> +     struct inv_icm42600_fifo_sensor_data accel;

> +     int8_t temp;

> +     int64_t timestamp;

> +};

> +

> +#define INV_ICM42600_SCAN_MASK_ACCEL_3AXIS                           \

> +     (BIT(INV_ICM42600_ACCEL_SCAN_X) |                               \

> +     BIT(INV_ICM42600_ACCEL_SCAN_Y) |                                \

> +     BIT(INV_ICM42600_ACCEL_SCAN_Z))

> +

> +#define INV_ICM42600_SCAN_MASK_TEMP  BIT(INV_ICM42600_ACCEL_SCAN_TEMP)

> +

> +static const unsigned long inv_icm42600_accel_scan_masks[] = {

> +     /* 3-axis accel + temperature */

> +     INV_ICM42600_SCAN_MASK_ACCEL_3AXIS | INV_ICM42600_SCAN_MASK_TEMP,

> +     0,

> +};

> +

> +static irqreturn_t inv_icm42600_accel_handler(int irq, void *_data)

> +{

> +     struct iio_poll_func *pf = _data;

> +     struct iio_dev *indio_dev = pf->indio_dev;

> +     struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);

> +     const size_t fifo_nb = st->fifo.nb.total;

> +     int ret;

> +

> +     /* exit if no sample */

> +     if (fifo_nb == 0)

> +             goto out;

> +

> +     ret = inv_icm42600_accel_parse_fifo(indio_dev, pf->timestamp);

> +     if (ret)

> +             dev_err(regmap_get_device(st->map), "accel fifo error %d\n",

> +                     ret);

> +

> +out:

> +     iio_trigger_notify_done(indio_dev->trig);

> +     return IRQ_HANDLED;

> +}

> +

> +/* enable accelerometer sensor and FIFO write */

> +static int inv_icm42600_accel_update_scan_mode(struct iio_dev *indio_dev,

> +                                            const unsigned long *scan_mask)

> +{

> +     struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);

> +     struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;

> +     unsigned int fifo_en = 0;

> +     unsigned int sleep_temp = 0;

> +     unsigned int sleep_accel = 0;

> +     unsigned int sleep;

> +     int ret;

> +

> +     mutex_lock(&st->lock);

> +

> +     if (*scan_mask & INV_ICM42600_SCAN_MASK_TEMP) {

> +             /* enable temp sensor */

> +             ret = inv_icm42600_set_temp_conf(st, true, &sleep_temp);

> +             if (ret)

> +                     goto out_unlock;

> +             fifo_en |= INV_ICM42600_SENSOR_TEMP;

> +     }

> +

> +     if (*scan_mask & INV_ICM42600_SCAN_MASK_ACCEL_3AXIS) {

> +             /* enable accel sensor */

> +             conf.mode = INV_ICM42600_SENSOR_MODE_LOW_NOISE;

> +             ret = inv_icm42600_set_accel_conf(st, &conf, &sleep_accel);

> +             if (ret)

> +                     goto out_unlock;

> +             fifo_en |= INV_ICM42600_SENSOR_ACCEL;

> +     }

> +

> +     /* update data FIFO write and FIFO watermark */

> +     ret = inv_icm42600_buffer_set_fifo_en(st, fifo_en | st->fifo.en);

> +     if (ret)

> +             goto out_unlock;

> +     ret = inv_icm42600_buffer_update_watermark(st);

> +

> +out_unlock:

> +     mutex_unlock(&st->lock);

> +     /* sleep maximum required time */

> +     if (sleep_accel > sleep_temp)

> +             sleep = sleep_accel;

> +     else

> +             sleep = sleep_temp;

> +     if (sleep)

> +             msleep(sleep);

> +     return ret;

> +}

> +

>  static int inv_icm42600_accel_read_sensor(struct inv_icm42600_state *st,

>                                          struct iio_chan_spec const *chan,

>                                          int16_t *val)

> @@ -250,6 +347,8 @@ static int inv_icm42600_accel_write_odr(struct inv_icm42600_state *st,

>        mutex_lock(&st->lock);

>        conf.odr = inv_icm42600_accel_odr_conv[idx / 2];

>        ret = inv_icm42600_set_accel_conf(st, &conf, NULL);

> +     inv_icm42600_buffer_update_fifo_period(st);

> +     inv_icm42600_buffer_update_watermark(st);

>        mutex_unlock(&st->lock);

>

>        pm_runtime_mark_last_busy(dev);

> @@ -512,12 +611,51 @@ static int inv_icm42600_accel_write_raw_get_fmt(struct iio_dev *indio_dev,

>        }

>  }

>

> +static int inv_icm42600_accel_hwfifo_set_watermark(struct iio_dev *indio_dev,

> +                                                unsigned int val)

> +{

> +     struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);

> +     int ret;

> +

> +     mutex_lock(&st->lock);

> +

> +     st->fifo.watermark.accel = val;

> +     ret = inv_icm42600_buffer_update_watermark(st);

> +

> +     mutex_unlock(&st->lock);

> +

> +     return ret;

> +}

> +

> +static int inv_icm42600_accel_hwfifo_flush(struct iio_dev *indio_dev,

> +                                        unsigned int count)

> +{

> +     struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);

> +     int ret;

> +

> +     if (count == 0)

> +             return 0;

> +

> +     mutex_lock(&st->lock);

> +

> +     ret = inv_icm42600_buffer_hwfifo_flush(st, count);

> +     if (!ret)

> +             ret = st->fifo.nb.accel;

> +

> +     mutex_unlock(&st->lock);

> +

> +     return ret;

> +}

> +

>  static const struct iio_info inv_icm42600_accel_info = {

>        .read_raw = inv_icm42600_accel_read_raw,

>        .read_avail = inv_icm42600_accel_read_avail,

>        .write_raw = inv_icm42600_accel_write_raw,

>        .write_raw_get_fmt = inv_icm42600_accel_write_raw_get_fmt,

>        .debugfs_reg_access = inv_icm42600_debugfs_reg,

> +     .update_scan_mode = inv_icm42600_accel_update_scan_mode,

> +     .hwfifo_set_watermark = inv_icm42600_accel_hwfifo_set_watermark,

> +     .hwfifo_flush_to_buffer = inv_icm42600_accel_hwfifo_flush,

>  };

>

>  int inv_icm42600_accel_init(struct inv_icm42600_state *st)

> @@ -525,6 +663,7 @@ int inv_icm42600_accel_init(struct inv_icm42600_state *st)

>        struct device *dev = regmap_get_device(st->map);

>        const char *name;

>        struct iio_dev *indio_dev;

> +     int ret;

>

>        name = devm_kasprintf(dev, GFP_KERNEL, "%s-accel", st->name);

>        if (!name)

> @@ -541,7 +680,51 @@ int inv_icm42600_accel_init(struct inv_icm42600_state *st)

>        indio_dev->modes = INDIO_DIRECT_MODE;

>        indio_dev->channels = inv_icm42600_accel_channels;

>        indio_dev->num_channels = ARRAY_SIZE(inv_icm42600_accel_channels);

> +     indio_dev->available_scan_masks = inv_icm42600_accel_scan_masks;

> +

> +     ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,

> +                                           inv_icm42600_accel_handler,

> +                                           &inv_icm42600_buffer_ops);

> +     if (ret)

> +             return ret;

> +

> +     indio_dev->trig = iio_trigger_get(st->trigger);

>

>        st->indio_accel = indio_dev;

>        return devm_iio_device_register(dev, st->indio_accel);

>  }

> +

> +int inv_icm42600_accel_parse_fifo(struct iio_dev *indio_dev, int64_t ts)

> +{

> +     struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);

> +     const size_t accel_nb = st->fifo.nb.accel;

> +     ssize_t i, size;

> +     const void *accel, *gyro, *temp, *timestamp;

> +     unsigned int odr;

> +     struct inv_icm42600_accel_buffer buffer;

> +

> +     /* exit if no accel sample */

> +     if (accel_nb == 0)

> +             return 0;

> +

> +     /* parse all fifo packets */

> +     for (i = 0; i < st->fifo.count; i += size) {

> +             size = inv_icm42600_fifo_decode_packet(&st->fifo.data[i],

> +                             &accel, &gyro, &temp, &timestamp, &odr);

> +             dev_dbg(regmap_get_device(st->map), "accel packet size = %zd\n",

> +                     size);

> +             /* quit if error or FIFO is empty */

> +             if (size <= 0)

> +                     return size;

> +             /* skip packet if no accel data or data is invalid */

> +             if (accel == NULL || !inv_icm42600_fifo_is_data_valid(accel)) {

> +                     dev_dbg(regmap_get_device(st->map), "skip accel data\n");

> +                     continue;

> +             }

> +             memcpy(&buffer.accel, accel, sizeof(buffer.accel));

> +             memcpy(&buffer.temp, temp, sizeof(buffer.temp));

> +             iio_push_to_buffers_with_timestamp(indio_dev, &buffer, ts);

> +     }

> +

> +     return 0;

> +}

> 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..b428abdc92ee

> --- /dev/null

> +++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c

> @@ -0,0 +1,353 @@

> +// SPDX-License-Identifier: GPL-2.0-or-later

> +/*

> + * Copyright (C) 2020 Invensense, Inc.

> + */

> +

> +#include <linux/device.h>

> +#include <linux/mutex.h>

> +#include <linux/pm_runtime.h>

> +#include <linux/regmap.h>

> +#include <linux/delay.h>

> +#include <linux/math64.h>

> +#include <linux/iio/iio.h>

> +#include <linux/iio/buffer.h>

> +#include <linux/iio/triggered_buffer.h>

> +#include <linux/iio/trigger_consumer.h>

> +

> +#include "inv_icm42600.h"

> +#include "inv_icm42600_buffer.h"

> +

> +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;

> +}

> +

> +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;

> +     int64_t latency_gyro, latency_accel, latency;

> +     unsigned int mask, val;

> +     bool restore;

> +     __le16 raw_wm;

> +     int ret;

> +

> +     packet_size = inv_icm42600_get_packet_size(st->fifo.en);

> +

> +     /* get minimal 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);

> +     period_gyro = inv_icm42600_odr_to_period(st->conf.gyro.odr);

> +     period_accel = inv_icm42600_odr_to_period(st->conf.accel.odr);

> +     latency_gyro = (int64_t)period_gyro * (int64_t)wm_gyro;

> +     latency_accel = (int64_t)period_accel * (int64_t)wm_accel;

> +     if (latency_gyro == 0) {

> +             latency = latency_accel;

> +             watermark = wm_accel;

> +     } else if (latency_accel == 0) {

> +             latency = latency_gyro;

> +             watermark = wm_gyro;

> +     } else {

> +             /* compute the smallest latency that is a multiple of both */

> +             if (latency_gyro <= latency_accel) {

> +                     latency = latency_gyro;

> +                     latency -= latency_accel % latency_gyro;

> +             } else {

> +                     latency = latency_accel;

> +                     latency -= 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 = div_s64(latency, period);

> +             if (watermark < 1)

> +                     watermark = 1;

> +     }

> +     wm_size = watermark * packet_size;

> +     dev_dbg(regmap_get_device(st->map), "watermark: %u (%zu)\n",

> +             watermark, wm_size);

> +

> +     /* changing FIFO watermark requires to turn off watermark interrupt */

> +     mask = INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN;

> +     val = 0;

> +     ret = regmap_update_bits_check(st->map, INV_ICM42600_REG_INT_SOURCE0,

> +                                    mask, val, &restore);

> +     if (ret)

> +             return ret;

> +

> +     raw_wm = INV_ICM42600_FIFO_WATERMARK_VAL(wm_size);

> +     ret = regmap_bulk_write(st->map, INV_ICM42600_REG_FIFO_WATERMARK,

> +                             &raw_wm, sizeof(raw_wm));

> +     if (ret)

> +             return ret;

> +

> +     /* restore watermark interrupt */

> +     if (restore) {

> +             mask = INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN;

> +             val = INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN;

> +             ret = regmap_update_bits(st->map, INV_ICM42600_REG_INT_SOURCE0,

> +                                      mask, val);

> +             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;

> +}

> +

> +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 = 0;

> +     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);

> +     else

> +             ret = inv_icm42600_set_accel_conf(st, &conf, &sleep);

> +

> +out_unlock:

> +     mutex_unlock(&st->lock);

> +     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 = iio_triggered_buffer_postenable,

> +     .predisable = iio_triggered_buffer_predisable,

> +     .postdisable = inv_icm42600_buffer_postdisable,

> +};

> +

> +int inv_icm42600_buffer_fifo_read(struct inv_icm42600_state *st,

> +                               unsigned int max)

> +{

> +     struct device *dev = regmap_get_device(st->map);

> +     __be16 raw_fifo_count;

> +     size_t max_count;

> +     ssize_t i, size;

> +     const void *accel, *gyro, *temp, *timestamp;

> +     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 */

> +     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_cpu(raw_fifo_count);

> +     dev_dbg(dev, "FIFO count = %zu\n", st->fifo.count);

> +

> +     /* check and sanitize 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_hwfifo_flush(struct inv_icm42600_state *st,

> +                                  unsigned int count)

> +{

> +     int64_t ts_gyro, ts_accel;

> +     int ret;

> +

> +     dev_dbg(regmap_get_device(st->map), "FIFO flush %u\n", count);

> +

> +     ts_gyro = iio_get_time_ns(st->indio_gyro);

> +     ts_accel = 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;

> +

> +     ret = inv_icm42600_gyro_parse_fifo(st->indio_gyro, ts_gyro);

> +     if (ret)

> +             return ret;

> +

> +     return inv_icm42600_accel_parse_fifo(st->indio_accel, ts_accel);

> +}

> +

> +int inv_icm42600_buffer_init(struct inv_icm42600_state *st)

> +{

> +     unsigned int mask, val;

> +     int ret;

> +

> +     /*

> +      * Default FIFO configuration (bits 7 to 5)

> +      * - use invalid value

> +      * - FIFO count in bytes

> +      * - FIFO count in big endian

> +      */

> +     mask = GENMASK(7, 5);

> +     val = INV_ICM42600_INTF_CONFIG0_FIFO_COUNT_ENDIAN;

> +     ret = regmap_update_bits(st->map, INV_ICM42600_REG_INTF_CONFIG0,

> +                              mask, val);

> +     if (ret)

> +             return ret;

> +

> +     /*

> +      * Enable FIFO partial read and continuous watermark interrupt.

> +      * Disable all FIFO EN bits.

> +      */

> +     mask = GENMASK(6, 5) | GENMASK(3, 0);

> +     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,

> +                               mask, val);

> +}

> diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.h b/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.h

> new file mode 100644

> index 000000000000..74b91c0e664b

> --- /dev/null

> +++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.h

> @@ -0,0 +1,162 @@

> +/* SPDX-License-Identifier: GPL-2.0-or-later */

> +/*

> + * Copyright (C) 2020 Invensense, Inc.

> + */

> +

> +#ifndef INV_ICM42600_BUFFER_H_

> +#define INV_ICM42600_BUFFER_H_

> +

> +#include <linux/kernel.h>

> +#include <linux/bits.h>

> +

> +struct inv_icm42600_state;

> +

> +#define INV_ICM42600_SENSOR_GYRO     BIT(0)

> +#define INV_ICM42600_SENSOR_ACCEL    BIT(1)

> +#define INV_ICM42600_SENSOR_TEMP     BIT(2)

> +

> +struct inv_icm42600_fifo {

> +     unsigned int en;

> +     uint32_t period;

> +     struct {

> +             unsigned int gyro;

> +             unsigned int accel;

> +     } watermark;

> +     size_t count;

> +     struct {

> +             size_t gyro;

> +             size_t accel;

> +             size_t total;

> +     } nb;

> +     uint8_t data[2080];

> +};

> +

> +/* 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)

> +

> +/* FIFO data packet */

> +struct inv_icm42600_fifo_sensor_data {

> +     __be16 x;

> +     __be16 y;

> +     __be16 z;

> +} __packed;

> +#define INV_ICM42600_FIFO_DATA_INVALID               -32768

> +

> +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

> +

> +static inline int16_t inv_icm42600_fifo_get_sensor_data(__be16 d)

> +{

> +     return be16_to_cpu(d);

> +}

> +

> +static inline bool

> +inv_icm42600_fifo_is_data_valid(const struct inv_icm42600_fifo_sensor_data *s)

> +{

> +     int16_t x, y, z;

> +

> +     x = inv_icm42600_fifo_get_sensor_data(s->x);

> +     y = inv_icm42600_fifo_get_sensor_data(s->y);

> +     z = inv_icm42600_fifo_get_sensor_data(s->z);

> +

> +     if (x == INV_ICM42600_FIFO_DATA_INVALID &&

> +                     y == INV_ICM42600_FIFO_DATA_INVALID &&

> +                     z == INV_ICM42600_FIFO_DATA_INVALID)

> +             return false;

> +

> +     return true;

> +}

> +

> +static inline ssize_t inv_icm42600_fifo_decode_packet(const void *packet,

Bit big to be in the header..

> +             const void **accel, const void **gyro, const void **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;

> +}

> +

> +extern const struct iio_buffer_setup_ops inv_icm42600_buffer_ops;

> +

> +int inv_icm42600_buffer_init(struct inv_icm42600_state *st);

> +

> +void inv_icm42600_buffer_update_fifo_period(struct inv_icm42600_state *st);

> +

> +int inv_icm42600_buffer_set_fifo_en(struct inv_icm42600_state *st,

> +                                 unsigned int fifo_en);

> +

> +int inv_icm42600_buffer_update_watermark(struct inv_icm42600_state *st);

> +

> +int inv_icm42600_buffer_fifo_read(struct inv_icm42600_state *st,

> +                               unsigned int max);

> +

> +int inv_icm42600_buffer_hwfifo_flush(struct inv_icm42600_state *st,

> +                                  unsigned int count);

> +

> +#endif

> diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c

> index 1102c54396e3..689089065ff9 100644

> --- a/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c

> +++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c

> @@ -14,6 +14,7 @@

>  #include <linux/iio/iio.h>

>

>  #include "inv_icm42600.h"

> +#include "inv_icm42600_buffer.h"

>

>  static const struct regmap_range_cfg inv_icm42600_regmap_ranges[] = {

>        {

> @@ -515,6 +516,11 @@ int inv_icm42600_core_probe(struct regmap *regmap, int chip, int irq,

>        if (ret)

>                return ret;

>

> +     /* setup FIFO buffer */

> +     ret = inv_icm42600_buffer_init(st);

> +     if (ret)

> +             return ret;

> +

>        /* setup interrupt trigger */

>        ret = inv_icm42600_trigger_init(st, irq, irq_type);

>        if (ret)

> @@ -559,6 +565,16 @@ static int __maybe_unused inv_icm42600_suspend(struct device *dev)

>                goto out_unlock;

>        }

>

> +     /* disable FIFO data streaming */

> +     if (iio_buffer_enabled(st->indio_gyro) ||

> +                     iio_buffer_enabled(st->indio_accel)) {

> +             /* 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;

> +     }

> +

>        ret = inv_icm42600_set_pwr_mgmt0(st, INV_ICM42600_SENSOR_MODE_OFF,

>                                         INV_ICM42600_SENSOR_MODE_OFF, false,

>                                         NULL);

> @@ -594,6 +610,13 @@ static int __maybe_unused inv_icm42600_resume(struct device *dev)

>        if (ret)

>                goto out_unlock;

>

> +     /* restore FIFO data streaming */

> +     if (iio_buffer_enabled(st->indio_gyro) ||

> +                     iio_buffer_enabled(st->indio_accel)) {

> +             ret = regmap_write(st->map, INV_ICM42600_REG_FIFO_CONFIG,

> +                                INV_ICM42600_FIFO_CONFIG_STREAM);

> +     }

> +

>  out_unlock:

>        mutex_unlock(&st->lock);

>        return ret;

> diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_gyro.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_gyro.c

> index c0164ab2830e..dafb104abc77 100644

> --- a/drivers/iio/imu/inv_icm42600/inv_icm42600_gyro.c

> +++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_gyro.c

> @@ -10,9 +10,13 @@

>  #include <linux/regmap.h>

>  #include <linux/delay.h>

>  #include <linux/iio/iio.h>

> +#include <linux/iio/buffer.h>

> +#include <linux/iio/triggered_buffer.h>

> +#include <linux/iio/trigger_consumer.h>

>

>  #include "inv_icm42600.h"

>  #include "inv_icm42600_temp.h"

> +#include "inv_icm42600_buffer.h"

>

>  #define INV_ICM42600_GYRO_CHAN(_modifier, _index, _ext_info)         \

>        {                                                               \

> @@ -46,6 +50,7 @@ enum inv_icm42600_gyro_scan {

>        INV_ICM42600_GYRO_SCAN_Y,

>        INV_ICM42600_GYRO_SCAN_Z,

>        INV_ICM42600_GYRO_SCAN_TEMP,

> +     INV_ICM42600_GYRO_SCAN_TIMESTAMP,

>  };

>

>  static const struct iio_chan_spec_ext_info inv_icm42600_gyro_ext_infos[] = {

> @@ -61,8 +66,100 @@ static const struct iio_chan_spec inv_icm42600_gyro_channels[] = {

>        INV_ICM42600_GYRO_CHAN(IIO_MOD_Z, INV_ICM42600_GYRO_SCAN_Z,

>                               inv_icm42600_gyro_ext_infos),

>        INV_ICM42600_TEMP_CHAN(INV_ICM42600_GYRO_SCAN_TEMP),

> +     IIO_CHAN_SOFT_TIMESTAMP(INV_ICM42600_GYRO_SCAN_TIMESTAMP),

>  };

>

> +/* IIO buffer data */

> +struct inv_icm42600_gyro_buffer {

> +     struct inv_icm42600_fifo_sensor_data gyro;

> +     int8_t temp;

> +     int64_t timestamp;

> +};

> +

> +#define INV_ICM42600_SCAN_MASK_GYRO_3AXIS                            \

> +     (BIT(INV_ICM42600_GYRO_SCAN_X) |                                \

> +     BIT(INV_ICM42600_GYRO_SCAN_Y) |                                 \

> +     BIT(INV_ICM42600_GYRO_SCAN_Z))

> +

> +#define INV_ICM42600_SCAN_MASK_TEMP  BIT(INV_ICM42600_GYRO_SCAN_TEMP)

> +

> +static const unsigned long inv_icm42600_gyro_scan_masks[] = {

> +     /* 3-axis gyro + temperature */

> +     INV_ICM42600_SCAN_MASK_GYRO_3AXIS | INV_ICM42600_SCAN_MASK_TEMP,

> +     0,

> +};

> +

> +static irqreturn_t inv_icm42600_gyro_handler(int irq, void *_data)

> +{

> +     struct iio_poll_func *pf = _data;

> +     struct iio_dev *indio_dev = pf->indio_dev;

> +     struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);

> +     const size_t fifo_nb = st->fifo.nb.total;

> +     int ret;

> +

> +     /* exit if no sample */

> +     if (fifo_nb == 0)

> +             goto out;

> +

> +     ret = inv_icm42600_gyro_parse_fifo(indio_dev, pf->timestamp);

> +     if (ret)

> +             dev_err(regmap_get_device(st->map), "gyro fifo error %d\n",

> +                     ret);

> +

> +out:

> +     iio_trigger_notify_done(indio_dev->trig);

> +     return IRQ_HANDLED;

> +}

> +

> +/* enable gyroscope sensor and FIFO write */

> +static int inv_icm42600_gyro_update_scan_mode(struct iio_dev *indio_dev,

> +                                           const unsigned long *scan_mask)

> +{

> +     struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);

> +     struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;

> +     unsigned int fifo_en = 0;

> +     unsigned int sleep_gyro = 0;

> +     unsigned int sleep_temp = 0;

> +     unsigned int sleep;

> +     int ret;

> +

> +     mutex_lock(&st->lock);

> +

> +     if (*scan_mask & INV_ICM42600_SCAN_MASK_TEMP) {

> +             /* enable temp sensor */

> +             ret = inv_icm42600_set_temp_conf(st, true, &sleep_temp);

> +             if (ret)

> +                     goto out_unlock;

> +             fifo_en |= INV_ICM42600_SENSOR_TEMP;

> +     }

> +

> +     if (*scan_mask & INV_ICM42600_SCAN_MASK_GYRO_3AXIS) {

> +             /* enable gyro sensor */

> +             conf.mode = INV_ICM42600_SENSOR_MODE_LOW_NOISE;

> +             ret = inv_icm42600_set_gyro_conf(st, &conf, &sleep_gyro);

> +             if (ret)

> +                     goto out_unlock;

> +             fifo_en |= INV_ICM42600_SENSOR_GYRO;

> +     }

> +

> +     /* update data FIFO write and FIFO watermark */

> +     ret = inv_icm42600_buffer_set_fifo_en(st, fifo_en | st->fifo.en);

> +     if (ret)

> +             goto out_unlock;

blank line

> +     ret = inv_icm42600_buffer_update_watermark(st);

> +

> +out_unlock:

> +     mutex_unlock(&st->lock);

> +     /* sleep maximum required time */

> +     if (sleep_gyro > sleep_temp)

> +             sleep = sleep_gyro;

> +     else

> +             sleep = sleep_temp;

> +     if (sleep)

> +             msleep(sleep);

if (sleep_gyro > sleep_temp)

msleep(sleep_gyro);

else

msleep(sleep_temp);

> +     return ret;

> +}

> +

>  static int inv_icm42600_gyro_read_sensor(struct inv_icm42600_state *st,

>                                         struct iio_chan_spec const *chan,

>                                         int16_t *val)

> @@ -262,6 +359,8 @@ static int inv_icm42600_gyro_write_odr(struct inv_icm42600_state *st,

>        mutex_lock(&st->lock);

>        conf.odr = inv_icm42600_gyro_odr_conv[idx / 2];

>        ret = inv_icm42600_set_gyro_conf(st, &conf, NULL);

> +     inv_icm42600_buffer_update_fifo_period(st);

> +     inv_icm42600_buffer_update_watermark(st);

>        mutex_unlock(&st->lock);

>

>        pm_runtime_mark_last_busy(dev);

> @@ -524,12 +623,51 @@ static int inv_icm42600_gyro_write_raw_get_fmt(struct iio_dev *indio_dev,

>        }

>  }

>

> +static int inv_icm42600_gyro_hwfifo_set_watermark(struct iio_dev *indio_dev,

> +                                               unsigned int val)

> +{

> +     struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);

> +     int ret;

> +

> +     mutex_lock(&st->lock);

> +

> +     st->fifo.watermark.gyro = val;

> +     ret = inv_icm42600_buffer_update_watermark(st);

> +

> +     mutex_unlock(&st->lock);

> +

> +     return ret;

> +}

> +

> +static int inv_icm42600_gyro_hwfifo_flush(struct iio_dev *indio_dev,

> +                                       unsigned int count)

> +{

> +     struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);

> +     int ret;

> +

> +     if (count == 0)

> +             return 0;

> +

> +     mutex_lock(&st->lock);

> +

> +     ret = inv_icm42600_buffer_hwfifo_flush(st, count);

> +     if (!ret)

> +             ret = st->fifo.nb.gyro;

> +

> +     mutex_unlock(&st->lock);

> +

> +     return ret;

> +}

> +

>  static const struct iio_info inv_icm42600_gyro_info = {

>        .read_raw = inv_icm42600_gyro_read_raw,

>        .read_avail = inv_icm42600_gyro_read_avail,

>        .write_raw = inv_icm42600_gyro_write_raw,

>        .write_raw_get_fmt = inv_icm42600_gyro_write_raw_get_fmt,

>        .debugfs_reg_access = inv_icm42600_debugfs_reg,

> +     .update_scan_mode = inv_icm42600_gyro_update_scan_mode,

> +     .hwfifo_set_watermark = inv_icm42600_gyro_hwfifo_set_watermark,

> +     .hwfifo_flush_to_buffer = inv_icm42600_gyro_hwfifo_flush,

>  };

>

>  int inv_icm42600_gyro_init(struct inv_icm42600_state *st)

> @@ -537,6 +675,7 @@ int inv_icm42600_gyro_init(struct inv_icm42600_state *st)

>        struct device *dev = regmap_get_device(st->map);

>        const char *name;

>        struct iio_dev *indio_dev;

> +     int ret;

>

>        name = devm_kasprintf(dev, GFP_KERNEL, "%s-gyro", st->name);

>        if (!name)

> @@ -553,7 +692,51 @@ int inv_icm42600_gyro_init(struct inv_icm42600_state *st)

>        indio_dev->modes = INDIO_DIRECT_MODE;

>        indio_dev->channels = inv_icm42600_gyro_channels;

>        indio_dev->num_channels = ARRAY_SIZE(inv_icm42600_gyro_channels);

> +     indio_dev->available_scan_masks = inv_icm42600_gyro_scan_masks;

> +

> +     ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,

> +                                           inv_icm42600_gyro_handler,

> +                                           &inv_icm42600_buffer_ops);

> +     if (ret)

> +             return ret;

> +

> +     indio_dev->trig = iio_trigger_get(st->trigger);

>

>        st->indio_gyro = indio_dev;

>        return devm_iio_device_register(dev, st->indio_gyro);

>  }

> +

> +int inv_icm42600_gyro_parse_fifo(struct iio_dev *indio_dev, int64_t ts)

> +{

> +     struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);

> +     const size_t gyro_nb = st->fifo.nb.gyro;

> +     ssize_t i, size;

> +     const void *accel, *gyro, *temp, *timestamp;

> +     unsigned int odr;

> +     struct inv_icm42600_gyro_buffer buffer;

> +

> +     /* exit if no gyro sample */

> +     if (gyro_nb == 0)

> +             return 0;

> +

> +     /* parse all fifo packets */

> +     for (i = 0; i < st->fifo.count; i += size) {

> +             size = inv_icm42600_fifo_decode_packet(&st->fifo.data[i],

> +                             &accel, &gyro, &temp, &timestamp, &odr);

> +             dev_dbg(regmap_get_device(st->map), "gyro packet size = %zd\n",

> +                     size);

> +             /* quit if error or FIFO is empty */

> +             if (size <= 0)

> +                     return size;

blank line here.

> +             /* skip packet if no gyro data or data is invalid */

> +             if (gyro == NULL || !inv_icm42600_fifo_is_data_valid(gyro)) {

> +                     dev_dbg(regmap_get_device(st->map), "skip gyro data\n");

Very noisy logging. I'd drop it for the final version of the driver.

> +                     continue;

> +             }

> +             memcpy(&buffer.gyro, gyro, sizeof(buffer.gyro));

> +             memcpy(&buffer.temp, temp, sizeof(buffer.temp));

buffer.temp = temp;

> +             iio_push_to_buffers_with_timestamp(indio_dev, &buffer, ts);

> +     }

> +

> +     return 0;

> +}

> diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_trigger.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_trigger.c

> index 7a5e76305f0b..5667e0204722 100644

> --- a/drivers/iio/imu/inv_icm42600/inv_icm42600_trigger.c

> +++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_trigger.c

> @@ -13,6 +13,7 @@

>  #include <linux/iio/trigger_consumer.h>

>

>  #include "inv_icm42600.h"

> +#include "inv_icm42600_buffer.h"

>

>  static irqreturn_t inv_icm42600_trigger_timestamp(int irq, void *_data)

>  {

> @@ -45,8 +46,18 @@ static irqreturn_t inv_icm42600_trigger_int_handler(int irq, void *_data)

>                dev_warn(dev, "FIFO full data lost!\n");

>

>        /* FIFO threshold reached */

> -     if (status & INV_ICM42600_INT_STATUS_FIFO_THS)

> -             iio_trigger_poll_chained(st->trigger);

> +     if (status & INV_ICM42600_INT_STATUS_FIFO_THS) {

> +             ret = inv_icm42600_buffer_fifo_read(st, 0);

> +             if (ret)

> +                     dev_err(dev, "FIFO read error %d\n", ret);

> +     } else {

> +             st->fifo.count = 0;

> +             st->fifo.nb.gyro = 0;

> +             st->fifo.nb.accel = 0;

> +             st->fifo.nb.total = 0;

> +     }

> +

> +     iio_trigger_poll_chained(st->trigger);

>

>  out_unlock:

>        mutex_unlock(&st->lock);