Re: [PATCH] ARM: dts: am437x-idk: Configure uart0 padconf wakeirq

[Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>]

* Vignesh R <vigneshr-l0cyMroinI0@public.gmane.org> [180212 04:53]:
> Hi,
> 
> On Friday 09 February 2018 09:49 PM, Tony Lindgren wrote:
> > We can use CTRL_CONF_UART0_RXD pad as the wakeirq and then
> > the serial console will work with wake up events.
> > 
> > Note that the uart still needs to be configured for idle
> > timeouts for PM runtime for the wakeirq to get activated.
> > That can be done via sysfs to set autosuspend_delay_ms to
> > 3000, wakeup enabled and and control auto.
> > 
> > Cc: Dave Gerlach <d-gerlach-l0cyMroinI0@public.gmane.org>
> > Signed-off-by: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
> > ---
> >  arch/arm/boot/dts/am437x-idk-evm.dts | 6 ++++++
> >  1 file changed, 6 insertions(+)
> > 
> > diff --git a/arch/arm/boot/dts/am437x-idk-evm.dts
> > b/arch/arm/boot/dts/am437x-idk-evm.dts
> > --- a/arch/arm/boot/dts/am437x-idk-evm.dts
> > +++ b/arch/arm/boot/dts/am437x-idk-evm.dts
> > @@ -533,3 +533,9 @@
> >                  opp-suspend;
> >          };
> >  };
> > +
> > +&uart0 {
> > +       /* UART0 interrupt and CTRL_CONF_UART0_RXD pad as wakeirq */
> > +       interrupts-extended = <&gic GIC_SPI 72 IRQ_TYPE_LEVEL_HIGH>,
> > +                             <&am43xx_pinmux 0x170>;
> > +};
> 
> As per Section 6.4.5 Wakeup Sources/Events AM437x TRM, UART0 is in
> Wakeup Power domain  and can wakeup the system directly. AFAIK, there is
> no need to use CTRL_CONF_UART0_RXD pad as the wakeirq.

OK, let's wait a bit on this until we can test suspend resume
with Dave's patches. I think this is still needed for runtime PM
as the UART is not able to wake up if it's configured for
autosuspend_delay_ms, or to wake up the system from suspend if the
UART is suspended.. But maybe you're right and the 8250 internal
wake-up can be used in this case :)

Regards,

Tony
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