Re: [PATCH v2 1/2] gpio/aspeed-sgpio: enable access to all 80 input & output sgpios

Andrew Jeffery andrew at
Fri Sep 11 13:28:06 AEST 2020

On Fri, 11 Sep 2020, at 11:21, Jeremy Kerr wrote:
> Currently, the aspeed-sgpio driver exposes up to 80 GPIO lines,
> corresponding to the 80 status bits available in hardware. Each of these
> lines can be configured as either an input or an output.
> However, each of these GPIOs is actually an input *and* an output; we
> actually have 80 inputs plus 80 outputs.
> This change expands the maximum number of GPIOs to 160; the lower half
> of this range are the input-only GPIOs, the upper half are the outputs.
> We fix the GPIO directions to correspond to this mapping.
> This also fixes a bug when setting GPIOs - we were reading from the
> input register, making it impossible to set more than one output GPIO.
> Signed-off-by: Jeremy Kerr <jk at>
> Fixes: 7db47faae79b ("gpio: aspeed: Add SGPIO driver")

This was something I was leaning on the implementer to sort out when I
reviewed the driver way back. Oh well.

Reviewed-by: Andrew Jeffery <andrew at>

More information about the Linux-aspeed mailing list