Re: [PATCH v4 2/3] gpio: vortex: add new GPIO device driver

[William Breathitt Gray <wbg@kernel.org>]

On Fri, Aug 22, 2025 at 03:58:12PM +0200, Marcos Del Sol Vives wrote:
> Add a new simple GPIO device driver for most DM&P Vortex86 SoCs,
> implemented according to their programming reference manuals [1][2][3].
> 
> Vortex86EX/EX2 use a radically different mechanism of GPIO control
> and are not supported by this driver.
> 
> This is required for detecting the status of the poweroff button and
> performing the poweroff sequence on ICOP eBox computers.
> 
> IRQs are not implemented, as they are only available for ports 0 and 1,
> none which are accessible on my test machine (an EBOX-3352-GLW).
> 
> [1]: https://www.vortex86.com/downloadsStart?serial=Vortex86SX/DX/MXPLUS
> [2]: https://www.vortex86.com/downloadsStart?serial=Vortex86DX2
> [3]: https://www.vortex86.com/downloadsStart?serial=Vortex86DX3
> 
> Signed-off-by: Marcos Del Sol Vives <marcos@orca.pet>

Hi Marcos,

Thank you for taking the time to develop and improve this driver. It can
be intimidating to submit patches and interface changes for public
review (especially without the help of the hardware company), so I
commend your continual efforts.

Regarding this GPIO driver, you've incorporated much of what I had
intended to comment on for your v2, so I'm comfortable leaving an Ack
for this version here.

Acked-by: William Breathitt Gray <wbg@kernel.org>

However, I do have a couple minor suggestions below if you decide to
submit a v5.

> +VORTEX HARDWARE SUPPORT
> +R:	Marcos Del Sol Vives <marcos@orca.pet>
> +S:	Maintained
> +F:	drivers/gpio/gpio-vortex.c

This driver only covers GPIO support so a better title for this
MAINTAINERS entry would be "VORTEX86 GPIO SUPPORT".

> +	rmcfg.reg_bits = 8;
> +	rmcfg.val_bits = 8;
> +	rmcfg.io_port = true;
> +	rmcfg.wr_table = &priv->access_table;
> +	rmcfg.rd_table = &priv->access_table;

The direction ports are expected to hold their previous state until they
are changed, so perhaps it would be beneficial to enable caching with a
rmcfg.cache_type = REGCACHE_FLAT and set a volatile_table which
excludes the data port range.

William Breathitt Gray