read-only hardware/fan discovery for Pankha fan-control

pankha-fan-diag.sh

#!/usr/bin/env bash
#
set -u

echo "=== Pankha fan diagnostic (read-only) ==="
echo "date    : $(date -Is 2>/dev/null)"
echo "host    : $(hostname 2>/dev/null)"
echo "kernel  : $(uname -r 2>/dev/null)"
echo "cmdline : $(cat /proc/cmdline 2>/dev/null)"

echo
echo "--- Super I/O / it87 module ---"
if lsmod 2>/dev/null | grep -qi it87; then
  lsmod 2>/dev/null | grep -i it87
  modinfo it87 2>/dev/null | grep -E '^(filename|version|srcversion):' || true
else
  echo "it87 NOT loaded (on ITE boards you may need: modprobe it87, often with"
  echo "  acpi_enforce_resources=lax or the driver's ignore_resource_conflict=1)"
fi

echo
echo "--- hwmon chips ---"
for h in /sys/class/hwmon/hwmon*; do
  [ -e "$h" ] || continue
  echo "$h -> $(cat "$h/name" 2>/dev/null)"
done

echo
echo "--- fan / pwm map ---"
echo "(pick a CHASSIS fan with rpm>0 and writable=yes for the control test)"
for h in /sys/class/hwmon/hwmon*; do
  [ -e "$h" ] || continue
  name=$(cat "$h/name" 2>/dev/null)
  for f in "$h"/fan[0-9]*_input; do
    [ -e "$f" ] || continue
    n=$(basename "$f" | sed 's/fan//; s/_input//')
    pp="$h/pwm${n}"
    pe="$h/pwm${n}_enable"
    printf '  %-12s %s fan%s: rpm=%-6s pwm=%-4s enable=%-3s writable=%s\n' \
      "$name" "$h" "$n" \
      "$(cat "$f" 2>/dev/null)" \
      "$( [ -e "$pp" ] && cat "$pp" 2>/dev/null || echo - )" \
      "$( [ -e "$pe" ] && cat "$pe" 2>/dev/null || echo - )" \
      "$( [ -w "$pp" ] && echo yes || echo no )"
  done
done

echo
echo "--- dmesg (it87 lines) ---"
dmesg 2>/dev/null | grep -i it87 | tail -n 20 || echo "(no it87 dmesg lines, or dmesg restricted)"

echo
echo "--- sensors ---"
if command -v sensors >/dev/null 2>&1; then
  sensors 2>/dev/null
else
  echo "(lm-sensors 'sensors' not installed)"
fi

echo
echo "=== done. Next: run pankha-pwm-test.sh on one chassis fan from the map above ==="