Re: [PATCH v3 15/15] docs: iio: add documentation for adxl345 driver

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 20 Feb 2025 10:42:34 +0000
Lothar Rubusch <l.rubusch@gmail.com> wrote:

> The documentation describes the ADXL345 driver, IIO interface,
> interface usage and configuration.
> 
> Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
> ---
>  Documentation/iio/adxl345.rst | 406 ++++++++++++++++++++++++++++++++++
>  1 file changed, 406 insertions(+)
>  create mode 100644 Documentation/iio/adxl345.rst
> 
> diff --git a/Documentation/iio/adxl345.rst b/Documentation/iio/adxl345.rst
> new file mode 100644
> index 000000000000..b77c97ef52e5
> --- /dev/null
> +++ b/Documentation/iio/adxl345.rst
> @@ -0,0 +1,406 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +===============
> +ADXL345 driver
> +===============
> +
> +This driver supports Analog Device's ADXL345/375 on SPI/I2C bus.
> +
> +1. Supported devices
> +====================
> +
> +* `ADXL345 <https://www.analog.com/ADXL345>`_
> +* `ADXL375 <https://www.analog.com/ADXL375>`_
> +
> +The ADXL345 is a generic purpose low power, 3-axis accelerometer with selectable
> +measurement ranges. The ADXL345 supports the ±2 g, ±4 g, ±8 g, and ±16 g ranges.
> +
> +2. Device attributes
> +====================
> +
> +Accelerometer measurements are always provided.

I'm not sure what this sentence is telling us. I'd drop it.

...


> +When activity and inactivity events are both enabled, the driver automatically
> +will implement its hysteresis solution by setting link bit and autosleep bit.
> +The link bit serially links the activity and inactivity functions. On the other
> +side, the autosleep function switches the sensor to sleep mode if the
> +inactivity function is enabled. This will reduce current consumption to the
> +sub-12.5Hz rate.
This makes me a little nervous as it's not particularly standard.
However I can't immediately think of a better way to handle it so maybe the
currently assumption of when to enable it is fine.


> +A double tap event can be invalidated in three ways: If the suppress bit is set,
> +any acceleration spike above the threshold already during the latency time
> +invalidates the double tap detection immediately, i.e. during latence must not
latency in the i.e bit? 
> +occur spikes for double tap detection with suppress bit set.

I'm finding the previous sentence hard to understand. Perhaps consider
rewording?

> +A double tap event is invalidated if acceleration lies above the threshold at
> +the start of the window time for the double tap detection.


Thanks,

Jonathan