Subject: Re: [PATCH 1/6] driver core: Add device_show_string() helper for sysfs attributes

From: Michael Ellerman <[email-masked]>
Date: Mon, 22 Apr 2024 15:38:54 +1000

Lukas Wunner <[email-masked]> writes:
> For drivers wishing to expose an unsigned long, int or bool at a static
> memory location in sysfs, the driver core provides ready-made helpers
> such as device_show_ulong() to be used as ->show() callback.
>
> Some drivers need to expose a string and so far they all provide their
> own ->show() implementation.  arch/powerpc/perf/hv-24x7.c went so far
> as to create a device_show_string() helper but kept it private.
>
> Make it public for reuse by other drivers.  The pattern seems to be
> sufficiently frequent to merit a public helper.
>
> Add a DEVICE_STRING_ATTR_RO() macro in line with the existing
> DEVICE_ULONG_ATTR() and similar macros to ease declaration of string
> attributes.
>
> Signed-off-by: Lukas Wunner <[email-masked]>
> ---
>  arch/powerpc/perf/hv-24x7.c | 10 ----------
>  drivers/base/core.c         |  9 +++++++++
>  include/linux/device.h      | 15 +++++++++++++++
>  3 files changed, 24 insertions(+), 10 deletions(-)

Acked-by: Michael Ellerman <[email-masked]> (powerpc)

cheers