[PATCH v5 00/10] ASPEED sgpio driver enhancement.
steven_lee at aspeedtech.com
Thu Jun 10 18:39:32 AEST 2021
The 06/10/2021 15:50, Linus Walleij wrote:
> On Thu, Jun 10, 2021 at 4:24 AM Steven Lee <steven_lee at aspeedtech.com> wrote:
> > 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
> BTW please influence Aspeed to use the GPIO character device
> and ligpiod
> 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
gpioget $chipId 0 2 4 6 8 ... 254
gpioset $chipId 1=1 3=0 5=1 7=1 ... 255=1
> Linus Walleij
More information about the Linux-aspeed