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Date: Sun, 17 Dec 2023 14:10:46 +0000
From: Jonathan Cameron <jic23@kernel.org>
To: =?UTF-8?B?TcOlcnRlbg==?= Lindahl <marten.lindahl@axis.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>, <linux-iio@vger.kernel.org>,
 <linux-kernel@vger.kernel.org>, <kernel@axis.com>
Subject: Re: [PATCH 0/2] Introduce new iio resolution standard attribute
Message-ID: <20231217141046.4cf3e34e@jic23-huawei>
In-Reply-To: <20231212-vcnl4000-ps-hd-v1-0-1c62a95828c0@axis.com>
References: <20231212-vcnl4000-ps-hd-v1-0-1c62a95828c0@axis.com>
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On Fri, 15 Dec 2023 13:43:03 +0100
M=C3=A5rten Lindahl <marten.lindahl@axis.com> wrote:

> This patch introduces a new IIO standard attribute to set the bit
> resolution of the data *_raw readings dynamically using sysfs.
>=20
> The VCNL4040/4200 proximity/ambient light sensors support 12-bit
> (default) and 16-bit ADC resolutions. This can be dynamically changed,
> so to support this with the standard iio channel configuration a new iio
> attribute should be added.
>=20
> The VCNL4040 devices will use this for setting proximity high definition
> (16-bit resolution).
>=20
> Signed-off-by: M=C3=A5rten Lindahl <marten.lindahl@axis.com>

Hi M=C3=A5rten,

What is the use case?  We've had lots of devices capable of doing this
sort of resolution change, but never yet come up with a reason to do so for
the sysfs interfaces on the basis the overhead of the sysfs interfaces is
high enough the best bet is almost always to use the highest available reso=
lution
and don't worry that the read takes a little longer.

Jonathan

> ---
> M=C3=A5rten Lindahl (2):
>       iio: core: Introduce resolution standard attribute
>       iio: light: vcnl4000: Add ps high definition for vcnl4040
>=20
>  drivers/iio/industrialio-core.c |  1 +
>  drivers/iio/light/vcnl4000.c    | 87 +++++++++++++++++++++++++++++++++++=
+++++-
>  include/linux/iio/types.h       |  1 +
>  3 files changed, 87 insertions(+), 2 deletions(-)
> ---
> base-commit: a39b6ac3781d46ba18193c9dbb2110f31e9bffe9
> change-id: 20231212-vcnl4000-ps-hd-38d42abf9095
>=20
> Best regards,