GPIO on Olimex A64 board. Bank E not working.

[Emmanuel Vadot]

 Hi Gary,

On Mon, 14 Oct 2019 14:46:12 -0400
Gary Otten <gdotten at gmail.com> wrote:

> I have successfully booted the FreeBSD on the Olimex board which has the
> Allwinner A64. I have been experimenting with the gpios,  again with
> success. However the 40 pin connector on the Olimex board exposes GPIO pins
> PB0 - PB4 which function normally (voltage corresponds to software setting
> for that pin)  and then PE0-PE17 which don't.     I have played with most
> of the PE0- PE17 pins with various settings, again nothing works, no signs
> of activity. I have successfully lit the LED (PE17) with the armbian
> (linux) distribution for this board so I know it should work.
> 
> Example
> gpioctl -f /dev/gpioc0 -c PB0 OUT
> gpioctl -f /dev/gpioc0 PB0 1
> 
> The pin PB0 then goes high (1) as expected.
> 
> gpioctl -f /dev/gpioc0 -c PE17 OUT
> gpioctl -f /dev/gpioc0 PE17 1
> 
> No activity on PE17
> 
> 
> I have dug into the the driver code a bit and the files containing the
> settings for this board/processor, but I have had no luck figuring it out.
>  I have studied the Allwinner a64 manual but I haven't had luck figuring
> out any other settings that might work.    I think I am missing a simple
> setting but can't figure it out, does anyone know how to get pins PE0 to
> PE17 to work? Thanks.

 What version of FreeBSD are you booting on this board ? 
 PE is a bit special on the Olinuxino as it's also used for MIPI-CSI
and it's drived at 2.8V by default. It's using the regulator ALDO1 from
the AXP PMIC and you should be able to confirm that it's enabled by
doing sysctl hw.regulator.vcc-pe
 Check for the .enable sysctl
 It should be on as there is the always-on property in the DTS.
 By default I think that the gpio pins are configured for 20mA so I
don't know if it would be enough for this led. If you have a multimeter
it would be good to confirm if you have any voltage on the ext
connector (you can use any PE pins, from what I see from the schematics
they are all safe to play with).

-- 
Emmanuel Vadot <manu at bidouilliste.com>