Wakeup the system from gpio interrupt

[sharmila_devada]

Hi,

I am using pcf2127 rtc module in my custom board. The GPIO3_16 is used for rtc alarm interrupt. Now I have to suspend the module and when rtc alarm interrupt comes, it should wake up. I am using below command for suspending the system

echo mem > /sys/power/state

When rtc alarm interrupt comes , the system is not waking up. The configuration I have made in my dts file is as below

gpio-keys {

    compatible = "gpio-keys";

    wakeup {

      label = "wakeup gpio";

      gpios = <&gpio3 16 GPIO_ACTIVE_LOW>;

      linux,code = <29>;

      gpio-key,wakeup;

    };

  };

But the system is not coming out of suspend mode. Please tell me where I am going wrong.

Thank You,

Regards,

Sharmila

[sharmila_devada]

Hi igor,

I have created suspend and resume function in my rtc driver as below

static int pcf2127_rtc_suspend(struct device *dev)
{
        struct pcf2127 *pdata = dev_get_drvdata(dev);

        if (device_may_wakeup(dev))
        {

               printk("pcf2127_rtc_suspend..\r\n");
                enable_irq_wake(irqNumber);
        }

        return 0;
}

static int pcf2127_rtc_resume(struct device *dev)
{
        struct pcf2127 *pdata = dev_get_drvdata(dev);

        if (device_may_wakeup(dev))
        {

               printk("pcf2127_rtc_suspend..\r\n");
                disable_irq_wake(irqNumber);
        }

        return 0;
}

Note : irqNumber is IRQ of GPIO which I got from gpio_to_irq(gpio_number).

when I suspend the system using echo mem > /sys/power/state command I am getting below prints

root@imx8dx_ccu:/usr/bin/ccu# echo mem > /sys/power/state
[   25.205302] PM: suspend entry (deep)
[   25.208888] PM: Syncing filesystems ... done.
[   25.242558] Freezing user space processes ... (elapsed 0.001 seconds) done.
[   25.250873] OOM killer disabled.
[   25.254121] Freezing remaining freezable tasks ... (elapsed 0.007 seconds) done.
[   25.273048] pcf2127_rtc_read_time..
[   25.277080] pcf2127_rtc_suspend..
[   25.280479] irq_set_irq_wake..
[   25.283642] irq_set_irq_wake..
[   25.288329] PM: suspend devices took 0.016 seconds
[   25.295436] Disabling non-boot CPUs ...
[   25.313505] CPU1: shutdown
[   25.316298] psci: CPU1 killed.

But system is not waking up when alarm interrupt comes.

Please provide some input.

Regards,

Sharmila

[mrcryo]

Hi Sharmila,

To use gpio as a wakeup source, one needed to configure pad-wakeup property for gpio node.

In your case it could be like:

/ {

   ...

   gpio-keys {

      compatible = "gpio-keys";

      wakeup {

         label = "wakeup gpio";

         gpios = <&gpio3 16 GPIO_ACTIVE_LOW>;

         linux,code = <KEY_WAKEUP>;

         wakeup-source;

      };

   };

   ...

};

&gpio3 {

   /* total pad wakeup number in gpio3 */

   pad-wakeup-num = <1>;

   /* SC_P_QSPI0A_SCLK, SC_PAD_WAKEUP_LOW_LVL, LINE 16 */

   /*

    * See include/dt-bindings/pinctrl/pads-imx8qxp.h

    * include/soc/imx8/sc/svc/pad/api.h

    * and drivers/gpio/gpio-mxc.c

    */
   pad-wakeup = <163 4 16>;
};

We're able to wake our custom module up with gpio using similar config.

[sharmila_devada]

Thank you,

After enabling pad wakeup, the wake up the system using gpio interrupt is working fine.

[sharmila_devada]

Hi igor,

Thank you for your support.

Our hardware doesn't have Power key option. Please tell me how to wake up the system using rtc interrupt.

Regards,

Sharmila

[igorpadykov]

Hi Sharmila

this part is preproduction part and unfortunately has not full support.

Suggest to proceed with extended support of Commercial Support and Engineering Services | NXP 

Best regards
igor

[igorpadykov]

Hi Sharmilla

one can check if gpio wakeup linux commits were implemented as mentioned below

Wakeup Source Configuration iMX8QXP/DX 

 dts example:
gpio4: gpio@5d0c0000 {
     compatible = "fsl,imx8qm-gpio", "fsl,imx35-gpio";
     reg = <0x0 0x5d0c0000 0x0 0x10000>;
     interrupts = <GIC_SPI 140 IRQ_TYPE_LEVEL_HIGH>;
     gpio-controller;
     #gpio-cells = <2>;
     power-domains = <&pd_lsio_gpio4>;
     interrupt-controller;
     #interrupt-cells = <2>;
     /* total pad wakeup number in gpio4 */
     pad-wakeup-num = <1>;
     /* SC_P_USDHC1_CD_B, SC_PAD_WAKEUP_LOW_LVL, LINE 22 */
     pad-wakeup = <27 4 22>;
};

Best regards
igor
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[sharmila_devada]

Hi,

I have made the above changes in my dtsi file and the result is same. Please tell me do I need to add any other changes such that my system will wake from suspend mode when rtc interrupt comes.

Regards,

Sharmila

[igorpadykov]

Hi Sharmila

also one can consider onoff pin as wake source:

      sc_pwrkey: sc-powerkey {
        compatible = "fsl,imx8-pwrkey";
        linux,keycode = <KEY_POWER>;
        wakeup-source;
    };

fsl-imx8dx.dtsi\freescale\dts\boot\arm64\arch - linux-imx - i.MX Linux kernel 

Best regards
igor