The 06/10/2021 15:50, Linus Walleij wrote:

On Thu, Jun 10, 2021 at 4:24 AM Steven Lee [off-list ref] wrote:

quoted

Per the comment in the following mail
https://lkml.org/lkml/2021/6/9/317

I was wondering if I should prepare v6 for the currnet solution or
I should drop this patch series then prepare another patch for the
new solution(piar GPIO input/output) which breaks userspace but is
better than the current solution.

I would say just go ahead with the new solution. AFAIK Aspeed
has pretty tight control over what kind of userspace run on these
systems.

BTW please influence Aspeed to use the GPIO character device
and ligpiod
https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git/
if you are doing any kind of userspace GPIO control (which I
suspect that you do).

We currently use gpioset and gpioget that provided by libgpiod to test
aspeed gpio and sgpio drivers.

For the current solution on AST2600,
the valid range of input pins  is 0 ~ 127,
the valid range of output pins is 128 ~ 255.
So we access input pins by the following command

gpioget $chipId 0 1 2 3 4 ... 127

and access output pins by the following command

gpioset $chipId 128=1 129=0 130=1 131=1 ... 255=1

The new solution will change the gpio id order as follows
Input:

gpioget $chipId 0 2 4 6 8 ... 254

Output:

gpioset $chipId 1=1 3=0 5=1 7=1 ... 255=1

Thanks,
Steven

Yours,
Linus Walleij