On Mon, Jul 5, 2021 at 1:59 AM Pkshih [off-list ref] wrote:

quoted

-----Original Message-----
From: Oleksij Rempel [mailto:o.rempel@pengutronix.de]

quoted

Based on this and other part of this driver I would recommend to use
regmap. It will provide to additional interface for the register
access. And typically for the network devices we have an ethtool
interface for that.

Could I know the 'regmap' you mentioned?

include/linux/regmap.h
drivers/base/regmap/

It's a driver framework and API for abstracting register accesses,
whether they are accessed directly via MMIO, or behind some kind of
indirect bus (I2C, SPI, etc.). It also happens to have its own debugfs
operators for doing various kinds of register get/set/dump. So if you
can successfully teach your driver to use it, then you don't need to
implement your own debugfs files for it.

I've only ever used regmap with Device Tree systems (which can more
easily specify syscon nodes, etc. -- see
Documentation/devicetree/bindings/regmap/regmap.txt). I'm totally
unfamiliar how to use this with ACPI (which I'm sure you want to
support). I'm sure it's possible somehow.

FWIW, search engines turn up a few basic articles about it, if you
find its documentation or code examples too sparse:
https://www.collabora.com/news-and-blog/blog/2020/05/27/using-regmaps-to-make-linux-drivers-more-generic/

Brian