#!/bin/sh
# systemd sleep hook: unload brcmfmac before deep sleep (S3) and hibernate, and load it again
# after resume, so the BCM43602 starts with fresh firmware instead of resuming.
# s2idle keeps the chip powered and doesn't need this.
# Install: sudo install -Dm755 brcmfmac-sleep /usr/lib/systemd/system-sleep/brcmfmac
# $1 = pre|post, $2 = suspend|hibernate|hybrid-sleep|suspend-then-hibernate
# suspend-then-hibernate runs "post" after the timed wake and "pre hibernate" right after it,
# so "post" waits for the driver to finish loading, and "pre" retries the unload.
case "$1/$2" in
    pre/suspend|pre/suspend-then-hibernate)
        grep -q '\[deep\]' /sys/power/mem_sleep || exit 0
        ;;
esac

wifi_up() {
    for n in /sys/class/net/*; do
        [ -d "$n/wireless" ] && return 0
    done
    return 1
}

case "$1" in
    pre)
        for _ in $(seq 1 20); do
            # brcmfmac_wcc/_cyw/_bca (vendor glue) hold a reference to brcmfmac; remove them first
            mods=$(lsmod | awk '$1 ~ /^brcmfmac_/ {print $1}')
            lsmod | grep -q '^brcmfmac ' || exit 0
            # shellcheck disable=SC2086
            modprobe -r $mods brcmfmac 2>/dev/null && exit 0
            sleep 0.5
        done
        echo "brcmfmac-sleep: could not unload brcmfmac" >&2
        ;;
    post)
        modprobe brcmfmac
        for _ in $(seq 1 30); do
            wifi_up && exit 0
            sleep 0.5
        done
        echo "brcmfmac-sleep: no Wi-Fi interface 15 s after loading brcmfmac" >&2
        ;;
esac
exit 0