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i.MX53 power management

Question asked by Vishakh M on Oct 10, 2014
Latest reply on Oct 31, 2014 by Vishakh M

Hi,

I am using imx53 custom board with linux-2.6.35 .

Trying to achieve power management in this platform.

PMIC used is ltc3589.

 

Currently trying to wakeup the system from "mem"(Sleep mode) using UART and gpios connected to buttons.

System is able to wake up using RTC alarm, but not able to wake up using UART and gpios.

 

GPIOs are generating interrupt on pressing the buttons in normal mode. GPIO voltage level is changing when button is pressed in low power mode.

Also noticed that there is no entry for "echo enabled > /sys/devices/gpio/<gpio_no>/power/wakeup".

 

For UART added following lines in drivers/serial/mxc_uart.c mxcuart_suspend function.

    if (device_may_wakeup(&pdev->dev)) {
            /* UART RTS signal is used as wakeup source */
            writel(MXC_UARTUCR1_RTSDEN, umxc->port.membase + MXC_UARTUCR1);
    }

 

But the above condition is not becoming true when mxcuart_suspend() is called.

 

Please, help me to configure GPIO  and UART as wake up source.

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