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Standby mode wakeup by GPIO

Gary Wu
Expert 3313 points

Hi,

    Does anyone test below function?

http://processors.wiki.ti.com/index.php/AM335x_Power_Management_Standby_User%27s_Guide#GPIO_wakeup

There is an issue when using GPIO for standby mode wakeup. I tested it on SK-EVM.

With waking up by GPIO, there are dozens of seconds no any feedback when press GPIO button after standby mode wakeup by GPIO.

  • 0
    TI__Intellectual 1165 points

    Wakeup from Standby via GPIO key press is a working feature.

    Please make sure you are using the latest code (kernel and Cortex M3 firmware).

    Does wakeup from standby happen via any other source? (touchscreen/uart etc)

    Regards

    Sandhya

  • 0 in reply to Sandhya Satyanarayana
    TI__Expert 3313 points

    Hi Sandhya,

         Thank you for your timely reply.

    I am using SDK-06.00.00.00 for test.

    For now, we tested DMtimer, UART0 and GPIO.

    As wiki page said,  standby wakeup by GPIO has been suppported. So I just want to check if there is the issue and how to fix it.

  • 0 in reply to Gary Wu
    TI__Intellectual 1165 points

    Hi Gary,

    Does wakeup from Standby happen for DMTimer and UART0?

    Does GPIO wakeup work for DeepSleep0?

    Regards

    Sandhya

  • 0 in reply to Sandhya Satyanarayana
    TI__Expert 3313 points

    Hi Sandhya,

         Yes, It's OK when using DMTimer and UART0 for standby wakeup.

    And it is also OK for DS0 wakeup when using GPIO. But there is the issue when using GPIO for standby wakeup.

    Could  you check it on starterkit? You can see the issue what I see.

  • 0 in reply to Gary Wu
    Expert 1210 points

    Hi,

    I've been working with Linux standby mode (TI-SDK 6.00), with wake-up from GPIO.

    One issue which can catch you out is that for GPIO wake-up, you must ensure that the GPIO is "free" for the standby wake-up code to use.  So if you are using /sys/class/gpio to read the GPIO in your embedded application, make sure you un-export the GPIO before going into standby.

    IE:

    # Wake on power key press from standby fails unless we unexport this:
    echo 28 > /sys/class/gpio/unexport

    # Wake on falling edge (ON key pressed)
    echo mii1_txd0.gpio0_28=0x27,falling > /debugfs/omap_mux/board/standby_gpio_pad_conf
    echo standby > /sys/power/state