On Sun, Feb 4, 2024 at 10:29 AM Peng Fan <peng.fan@xxxxxxx> wrote: > Using generic pinconf means the firmware needs exporting groups/functions/pins > and etc, the firmware design will be complicated and code size enlarged. This is very much to the core of the problem isn't it? So the argument is to save code effort and size in the firmware. This reflects some of the reasoning behind the device tree bindings that encode "magic numbers" in the DT nodes to mux and configure pins. Often the argument is that it saves space and effort. When the i.MX driver was first discussed it used the standard scheme actually. Look at i.MX 53 for example: https://lore.kernel.org/linux-kernel/1322999384-7886-2-git-send-email-b29396@xxxxxxxxxxxxx/ Groups and functions! As strings! Then the DT bindings were discussed back and forth between Dong Aisheng (the original driver author), Sasha Hauer and Shawn Guo before arriving at the fsl,pins scheme. Back in the day I was pretty much clueless about device tree and relied on others to review the bindings, which ended up like this: Documentation/devicetree/bindings/pinctrl/fsl,imx-pinctrl.txt This was in 2011/2012 so many things were not considered. It is clear that this scheme with a number of integers that get poked into registers is convenient for some DT authors, also pinctrl-single uses this as well as I think Mediatek and maybe a few others. Over the years I have come to regret it a bit, I think insisting on groups and functions as strings is better for abstraction. And the point of firmware is to abstract things so they work the same on all systems. Yours, Linus Walleij
