On Fri, 27 Mar 2020 15:34:43 -0700
Gwendal Grignou <gwendal@xxxxxxxxxxxx> wrote:
> Add buffer/hwfifo_flush. It is not part of the ABI, but it follows ST
> and HID lead: Tells the sensor hub to send to the host all pending
> sensor events.
>
> Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
Unless I'm missing something there aren't any other drivers providing
an explicit flush attribute. The nearest equivalent is the flush
callback which reads out stuff that is in a fifo to be read, but which
hasn't yet reached a watermark to trigger normal readback.
Can we do something similar here?
If not this needs ABI documentation in Documentation/ABI/testing/...
I'm not keen on it in becoming general ABI unless I'm missing a
strong argument in favour of it.
Jonathan
> ---
> No changes in v7.
> New in v6.
>
> .../cros_ec_sensors/cros_ec_sensors_core.c | 28 +++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> index c831915ca7e56..aaf124a82e0e4 100644
> --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> @@ -113,6 +113,33 @@ static int cros_ec_sensor_set_ec_rate(struct cros_ec_sensors_core_state *st,
> return ret;
> }
>
> +static ssize_t cros_ec_sensors_flush(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> + struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
> + int ret = 0;
> + bool flush;
> +
> + ret = strtobool(buf, &flush);
> + if (ret < 0)
> + return ret;
> + if (!flush)
> + return -EINVAL;
> +
> + mutex_lock(&st->cmd_lock);
> + st->param.cmd = MOTIONSENSE_CMD_FIFO_FLUSH;
> + ret = cros_ec_motion_send_host_cmd(st, 0);
> + if (ret != 0)
> + dev_warn(&indio_dev->dev, "Unable to flush sensor\n");
> + mutex_unlock(&st->cmd_lock);
> + return ret ? ret : len;
> +}
> +
> +static IIO_DEVICE_ATTR(hwfifo_flush, 0644, NULL,
> + cros_ec_sensors_flush, 0);
> +
> static ssize_t cros_ec_sensor_set_report_latency(struct device *dev,
> struct device_attribute *attr,
> const char *buf, size_t len)
> @@ -175,6 +202,7 @@ static ssize_t hwfifo_watermark_max_show(struct device *dev,
> static IIO_DEVICE_ATTR_RO(hwfifo_watermark_max, 0);
>
> const struct attribute *cros_ec_sensor_fifo_attributes[] = {
> + &iio_dev_attr_hwfifo_flush.dev_attr.attr,
> &iio_dev_attr_hwfifo_timeout.dev_attr.attr,
> &iio_dev_attr_hwfifo_watermark_max.dev_attr.attr,
> NULL,
