Re: [PATCH v5 2/3] tty: serial: qcom_geni_serial: Wakeup over UART RX

Stephen Boyd
2019-11-15T19:41:41Z

Quoting Akash Asthana (2019-11-15 02:00:44)
>
> On 11/14/2019 11:10 PM, Stephen Boyd wrote:
> > Quoting Akash Asthana (2019-11-13 02:48:56)
> >> Add system wakeup capability over UART RX line for wakeup capable UART.
> >> When system is suspended, RX line act as an interrupt to wakeup system
> >> for any communication requests from peer.
> > How does the RX line get remuxed as a GPIO interrupt here? Is that
> > through some pinctrl magic in DT or just via enabling/disabling the
> > interrupt?
> Yes, For wakeup capable UART node, we have registered UART RX line with
> TLMM interrupt controller in DT file . Example: if GPIO48 is UART RX line
>
> interrupts-extended =  <&intc GIC_SPI 607 IRQ_TYPE_LEVEL_HIGH>,  <&tlmm
> 48 IRQ_TYPE_EDGE_FALLING>;

Right. So is gpio48 muxed as 'uart' function forever and the interrupt
logic in tlmm is connected to that pad regardless of the function
selected? I thought that gpios through TLMM had to be muxed as function
0, i.e. gpio function, so that interrupts worked. But maybe that's wrong
and it can work without that.