[PATCH 2/3] corenet: Support gpio power/reset for corenet

[Scott Wood]

On 09/06/2016 02:12 PM, Andy Fleming wrote:
> Boards can implement power and reset functionality over gpio using
> these drivers:
>   drivers/power/reset/gpio-poweroff.c
>   drivers/power/reset/gpio-restart.c
> 
> While not all corenet boards use gpio for power/reset, this
> support can be added without interfering with boards that do not
> use this functionality.
> 
> If a board's device tree has the related nodes, they are now probed.
> Also, gpio-poweroff uses the global pm_power_off callback to implement
> the shutdown. However, pm_power_off was not invoked when the kernel
> halted, although that is usually the desired behavior. If the board
> provides gpio power and reset support, it is reasonable to assume that
> halting should also power down the system, unless it has chosen to
> pass those calls on to hypervisor.

Halt and poweroff are not the same thing.  If userspace requests a
poweroff, then kernel_power_off() will call machine_power_off() which
will call pm_power_off().

Why do we need anything corenet-specific here?

> @@ -127,6 +137,12 @@ static const struct of_device_id of_device_ids[] = {
>  	{
>  		.name		= "handles",
>  	},
> +	{
> +		.name		= "gpio-poweroff",
> +	},
> +	{
> +		.name		= "gpio-restart",
> +	},
>  	{}
>  };
>  

I don't see any other platforms doing this.  How do the nodes get probed
for them?

-Scott