nPM1300 does not exit ship hold mode when SHPHLD button pressed or VBUS connected

[joelspadin]

Hello,

I have custom hardware using an nPM1300 and nRF52840, and I am having trouble getting the nPM1300 to work as described in its documentation. I have a button connected between the SHPHLD pin and ground, and I can tell it is working because I get GPIO events, and a long press does reset the nPM1300. However, if I enable ship hold mode, then it does not exit ship hold mode with either a short press of the button or plugging in USB. I can only get it to exit with a long press.

You can see my hardware at kicanvas.org/?github=https%3A%2F%2Fgithub.com%2Fjoelspadin%2Fmarten_numpad%2Fblob%2Fmain%2Fpcb%2Fnumpad.kicad_pro. The relevant schematics are in usb.kicad_sch and numpad.kicad_sch.

I am using Zephyr 4.1. My devicetree setup for the nPM1300 looks like this:

&i2c0 {
    compatible = "nordic,nrf-twi";
    status = "okay";

    pinctrl-0 = <&i2c0_default>;
    pinctrl-1 = <&i2c0_sleep>;
    pinctrl-names = "default", "sleep";

    npm1300_pmic: pmic@6b {
        compatible = "nordic,npm1300";
        status = "okay";
        reg = <0x6b>;

        host-int-gpios = <&gpio0 30 0>;
        pmic-int-pin = <1>;
        long-press-reset = "one-button";

        npm1300_regulators: regulators {
            compatible = "nordic,npm1300-regulator";

            main_regulator: BUCK2 {
                regulator-min-microvolt = <3300000>;
                regulator-max-microvolt = <3300000>;
                regulator-always-on;
            };
        };

        npm1300_charger: charger {
            compatible = "nordic,npm1300-charger";
            charging-enable;

            term-microvolt = <4150000>;
            term-warm-microvolt = <4000000>;
            current-microamp = <250000>;
            dischg-limit-microamp = <1000000>;
            vbus-limit-microamp = <500000>;

            // No thermistor
            thermistor-ohms = <0>;
            thermistor-beta = <3380>;
        };

        npm1300_leds: leds {
            compatible = "nordic,npm1300-led";
            nordic,led0-mode = "charging";
            nordic,led1-mode = "host";
            nordic,led2-mode = "host";
        };
    };
};

Using

    static struct gpio_callback event_cb;
    gpio_init_callback(&event_cb, power_button_callback, BIT(NPM1300_EVENT_SHIPHOLD_PRESS));
    mfd_npm1300_add_callback(pmic, &event_cb);

I have set up a callback which checks if USB is powered. If not, it blinks an LED a few times, then calls regulator_parent_ship_mode(). With the board powered only from a battery, when I press the button, the LED blinks, then it shuts off and the voltage to the SoC drops to 0 as expected. When I press the button again, nothing happens. (I can tell it is not waking, immediately triggering the GPIO event, and then going back into ship mode, because the LED does not blink.) Similarly, reconnecting USB power does not wake it either.

Is there something else I'm missing that needs to be configured?

[joelspadin]

On the nPM1300 EK, I see VSYS is at 4 V when powered by battery, ~3.5 V and slowly dropping towards 0 in ship/hibernate mode, and 4 V after I press the reset button.

On my custom hardware,

	VSYS	RSTCAUSE on short press	RSTCAUSE on long press	RSTCAUSE on USB plugged in	RSTCAUSE on wake from timer
Powered on USB	5 V	N/A	LONGPRESSTIMEOUT	N/A	N/A
Powered on battery	4 V	N/A		N/A	N/A
Hibernate	3.8 V and slowly dropping towards 0	SHIPMODEEXIT	Not possible. Wakes immediately when button is pressed.	SHIPMODEEXIT	SHIPMODEEXIT
Ship mode	4 V (steady)	Does not wake.	LONGPRESSTIMEOUT	RSTCAUSE is unchanged	N/A

I assume that this behavior with the voltage slowly dropping is just a capacitor discharging, and my multimeter is the only load on the circuit? Regardless, I do see a clear difference between the VSYS behaviors in hibernate and ship modes on my hardware. My hardware in hibernate mode matches the EK in ship and hibernate modes, but my hardware in ship mode has VSYS steady at 4 V.

[Tomi Koskela]

Hello,

Yes it is expected for the VSYS voltage drop slowly when the capacitors get discharged. But it seems something is keeping the VSYS voltage up in your system in ship mode, that is definitely not normal. And why hibernate mode works, but ship mode does not that is strange as well..

[joelspadin]

At this point, the only things I can think of are:

1. Maybe there's a bug in Zephyr's driver, and it's not entering hibernate properly? I will check if there are any differences between the driver in Zephyr 4.1, mainline Zephyr, and the Nordic SDK later.
2. I assumed that ship mode was effectively just hibernate but without the wake timer. Is that correct, or are there other differences between them at the hardware level? If there are any differences, that could point to where to look for hardware issues in my design, since hibernate works (mostly) correctly but ship mode doesn't.

(It is odd that hibernate only sleeps for 10 seconds when I asked for 30,000 ms. I still need to debug that.)

[Tomi Koskela]

Hi,

Yes the hibernate mode is essentially the same as ship mode, but the wakeup is with timer instead of button. We will also check the hibernate timer issue you mentioned, is there something in our driver that needs to be updated. 10s would be the same as the boot timer.

[Tomi Koskela]

Hi,

There has been a fix to the hibernate mode entry which will effect the time you set. This has been fixed upstream, but it's not in the SDK yet. You can see the patch here:

https://github.com/zephyrproject-rtos/zephyr/pull/98654/files