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

* Vignesh R [off-list ref] [180212 04:53]:

Hi,

On Friday 09 February 2018 09:49 PM, Tony Lindgren wrote:

quoted

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 <redacted>
Signed-off-by: Tony Lindgren <redacted>
---
 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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