Re: [PATCH v6 3/9] iio: imu: inv_icm45600: add buffer support in iio devices

[Jonathan Cameron <jic23@kernel.org>]

On Wed, 1 Oct 2025 12:07:40 +0000
Remi Buisson <Remi.Buisson@tdk.com> wrote:

> >
> >
> >From: Jonathan Cameron <jic23@kernel.org> 
> >Sent: Sunday, September 28, 2025 10:45 AM
> >To: Remi Buisson via B4 Relay <devnull+remi.buisson.tdk.com@kernel.org>
> >Cc: Remi Buisson <Remi.Buisson@tdk.com>; David Lechner <dlechner@baylibre.com>; Nuno Sá <nuno.sa@analog.com>; Andy Shevchenko <andy@kernel.org>; Rob Herring <robh@kernel.org>; Krzysztof Kozlowski <krzk+dt@kernel.org>; Conor Dooley <conor+dt@kernel.org>; linux-kernel@vger.kernel.org; linux-iio@vger.kernel.org; devicetree@vger.kernel.org
> >Subject: Re: [PATCH v6 3/9] iio: imu: inv_icm45600: add buffer support in iio devices
> >
> >On Wed, 24 Sep 2025 09:23:56 +0000
> >Remi Buisson via B4 Relay <devnull+remi.buisson.tdk.com@kernel.org> wrote:
> >  
> >> From: Remi Buisson <remi.buisson@tdk.com>
> >> 
> >> Add FIFO control functions.
> >> Support hwfifo watermark by multiplexing gyro and accel settings.
> >> Support hwfifo flush.
> >> 
> >> Signed-off-by: Remi Buisson <remi.buisson@tdk.com>  
> >Hi Remi,
> >
> >A few trivial things in here as well.
> >
> >Jonathan  
> Thanks again for the review !
> Remi
> >  
> >> diff --git a/drivers/iio/imu/inv_icm45600/inv_icm45600.h b/drivers/iio/imu/inv_icm45600/inv_icm45600.h
> >> index 5f637e2f2ec8f1537459459dbb7e8a796d0ef7a6..aac8cd852c12cfba5331f2b7c1ffbbb2ed23d1c7 100644
> >> --- a/drivers/iio/imu/inv_icm45600/inv_icm45600.h
> >> +++ b/drivers/iio/imu/inv_icm45600/inv_icm45600.h
> >> @@ -5,6 +5,7 @@
> >>  #define INV_ICM45600_H_
> >>  
> >>  #include <linux/bits.h>
> >> +#include <linux/limits.h>  
> >
> >Why this in the header?  Should be only needed in some of the c files I think
> >so push the include down there.  
> This is because the below line uses U8_MAX:
> #define INV_ICM45600_SENSOR_CONF_KEEP_VALUES { U8_MAX, U8_MAX, U8_MAX, U8_MAX }
> So I guess the header from where it comes from should be included.
> Please correct if I miss something.

Nope. Should indeed be there. I just missed that.

> >  
> ...
> >  
> >> diff --git a/drivers/iio/imu/inv_icm45600/inv_icm45600_buffer.h b/drivers/iio/imu/inv_icm45600/inv_icm45600_buffer.h
> >> new file mode 100644
> >> index 0000000000000000000000000000000000000000..0c8caa8287dd4373cf11bb6c7b913a6c49e9eee5
> >> --- /dev/null
> >> +++ b/drivers/iio/imu/inv_icm45600/inv_icm45600_buffer.h  
> >  
> >> +
> >> +/**
> >> + * struct inv_icm45600_fifo - FIFO state variables
> >> + * @on:		reference counter for FIFO on.
> >> + * @en:		bits field of INV_ICM45600_SENSOR_* for FIFO EN bits.
> >> + * @period:	FIFO internal period.
> >> + * @watermark:	watermark configuration values for accel and gyro.  
> >Given the contents of this to me look like things to also document.e
> > * @watermark.gyro:	....
> >etc as well would be good to add
> >  
> >> + * @count:	number of bytes in the FIFO data buffer.
> >> + * @nb:		gyro, accel and total samples in the FIFO data buffer.  
> >
> >This is more obvious.  Check if the kernel-doc script minds these subfields not
> >being defined.  If it does, add a the trivial documentation just to squash warnings
> >and make it easier to spot real issues.  
> 
> With my setup "./scripts/kernel-doc.py -v -none drivers/iio/imu/inv_icm45600/*" does not catch anything, even with -Wall.
> I'll detail the gyro/accel watermark comment anyway.

I guess it doesn't mind not documenting nested structure elements

Jonathan

>