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    SubjectRe: at91sam9260 wakeup on serial port
    > On Monday 28 January 2008, Haavard Skinnemoen wrote:
    >> On Mon, 28 Jan 2008 12:15:00 +0100
    >> michael <> wrote:
    >> > Hi,
    >> > I implement a little patch (ndr just for a try) for the atmel serial
    >> > driver atmel_serial.c to wakeup the system when it is in suspend-ram
    >> state.
    >> > I reconfigure the RXD pin as a gpio in suspend function and restore it
    >> > in the resume function. It is the correct way?
    >> I'm not sure...this is rather platform-specific, so I don't think it
    >> really belongs in the atmel_serial() driver. One solution might be to
    >> add a function pointer to struct atmel_uart_data that the driver can
    >> call from ->suspend() in order to let the platform code handle this as
    >> appropriate.
    > The core issue is that the system clock driving the baud rate generator
    > is no longer running fast enough to let the UART run. (In "standby" the
    > clock is still driven by the PLL, so this issue doesn't come up.) The
    > GPIO logic can catch the START bit though ... this technique is used on
    > some OMAP boards too.
    > Agreed that knowing exactly which pin(s) should be remuxed (UARTn.RX to
    > GPIO in suspend then enabling it as a wakeup irq, then reversing that
    > on resume; maybe UARTn.DCD should work too..), and how (as A-peripheral?
    > or B?) is chip-specific knowledge. Such a function pointer could work.
    > What will AVR32 (AP7) need to do, when it supports system sleep states?
    > - Dave
    My code just works and I can try to implement a clean patches and submit to
    the mailing list.


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