[buildroot] Enable power button in BBB

[Szymon Kempny]

How to enable power button in Beaglebone Black Rev C?

Here is my device tree from i2c and tps:

    i2c0_pins: pinmux_i2c0_pins {

       pinctrl-single,pins = <

           AM33XX_IOPAD(0x988, PIN_INPUT_PULLUP | MUX_MODE0)   /* i2c0_sda.i2c0_sda */

           AM33XX_IOPAD(0x98c, PIN_INPUT_PULLUP | MUX_MODE0)   /* i2c0_scl.i2c0_scl */

       >;

   };

&i2c0 {

   pinctrl-names = "default";

   pinctrl-0 = <&i2c0_pins>;

    status = "okay";

   clock-frequency = <400000>;

    tps: tps@24 {

       reg = <0x24>;

   };

    baseboard_eeprom: baseboard_eeprom@50 {

       compatible = "atmel,24c256";

       reg = <0x50>;

        #address-cells = <1>;

       #size-cells = <1>;

       baseboard_data: baseboard_data@0 {

           reg = <0 0x100>;

       };

   };

};

&tps {

   /*

    * Configure pmic to enter OFF-state instead of SLEEP-state ("RTC-only

    * mode") at poweroff.  Most BeagleBone versions do not support RTC-only

    * mode and risk hardware damage if this mode is entered.

    *

    * For details, see linux-omap mailing list May 2015 thread

    *  [PATCH] ARM: dts: am335x-bone* enable pmic-shutdown-controller

    * In particular, messages:

    *  http://www.spinics.net/lists/linux-omap/msg118585.html

    *  http://www.spinics.net/lists/linux-omap/msg118615.html

    *

    * You can override this later with

    *  &tps {  /delete-property/ ti,pmic-shutdown-controller;  }

    * if you want to use RTC-only mode and made sure you are not affected

    * by the hardware problems. (Tip: double-check by performing a current

    * measurement after shutdown: it should be less than 1 mA.)

    */

    interrupts = <7>; /* NMI */

   interrupt-parent = <&intc>;

    ti,pmic-shutdown-controller;

    charger {

       status = "okay";

   };

    pwrbutton {

       status = "okay";

   };

    regulators {

       dcdc1_reg: regulator@0 {

           regulator-name = "vdds_dpr";

           regulator-always-on;

       };

        dcdc2_reg: regulator@1 {

           /* VDD_MPU voltage limits 0.95V - 1.26V with +/-4% tolerance */

           regulator-name = "vdd_mpu";

           regulator-min-microvolt = <925000>;

           regulator-max-microvolt = <1351500>;

           regulator-boot-on;

           regulator-always-on;

       };

        dcdc3_reg: regulator@2 {

           /* VDD_CORE voltage limits 0.95V - 1.1V with +/-4% tolerance */

           regulator-name = "vdd_core";

           regulator-min-microvolt = <925000>;

           regulator-max-microvolt = <1150000>;

           regulator-boot-on;

           regulator-always-on;

       };

        ldo1_reg: regulator@3 {

           regulator-name = "vio,vrtc,vdds";

           regulator-always-on;

       };

        ldo2_reg: regulator@4 {

           regulator-name = "vdd_3v3aux";

           regulator-always-on;

       };

        ldo3_reg: regulator@5 {

           regulator-name = "vdd_1v8";

           regulator-always-on;

       };

        ldo4_reg: regulator@6 {

           regulator-name = "vdd_3v3a";

           regulator-always-on;

       };

   };

};

Im using kernel 4.19.79

On default Debian image:

- when i press power button then the system is power off and power LED is off

- when i run `poweroff` then system is going down and power led is OFF

On my buildroot image:

- when i press power button nothing happend

- when i run `poweroff` then system is going down and power led is still ON

How to enable full power support in buildroot image?

Regards,

Szymon
 

[Robert Nelson]

In debian, the power button get's mapped to a KEY_POWER, and systemd
initiates shutdown..

Are you using systemd in your buildroot image? If so what version?
Pre-systemd we use to use an acpi-tool to help shutdown, it wasn't the
greatest..

Regards,

--
Robert Nelson
https://rcn-ee.com/

[Szymon Kempny]

Thanks for quick response.

Im using Busybox, but i can try build with systemd tomorrow.

Is there a quick way to overwrite power off sequence using busybox to make it work correctly?

Working power button isn't nesesery im my case.