Many of the charge-limit related functions of tlp are Thinkpad-exclusive, but, according to the manual, tlp fullcharge is not. Yet, when I try it, I get Error: battery charge thresholds not available. Before I spend effort on this, I’d like to hear whether it’s even possible on the Framework 13. Since the laptop does have a charge limiting function in the UEFI, it seems like interoperability with programs like tlp might have been a design consideration.
Has anyone seen this work?
Charge limit is not exposed through to the sysfs interface that tlp uses, at least not yet. @DHowett might know if there’s some effort to get that into the kernel.
I have it working on my Framework laptop running Gentoo, first loaded this kernel module:
Then I put this at /usr/share/tlp/bat.d/41-framework (it’s a hacked up version of the template that TLP provides):
#!/bin/sh
# Copyright (c) 2023 Thomas Koch <linrunner at gmx.net> and others.
# SPDX-License-Identifier: GPL-2.0-or-later
# Needs: tlp-func-base, 35-tlp-func-batt, tlp-func-stat
# --- Hardware Detection
readonly BATDRV_FRAMEWORK_MD=/sys/module/framework_laptop
batdrv_is_framework () {
# check if vendor specific kernel module is loaded
# rc: 0=ok, 1=other hardware
[ -d $BATDRV_FRAMEWORK_MD ]
}
# --- Plugin API functions
batdrv_init () {
# detect hardware and initialize driver
# rc: 0=matching hardware detected/1=not detected/2=no batteries detected
# retval: $_batdrv_plugin, $_batdrv_kmod
#
# 1. check for native kernel acpi (Linux 5.4 or higher required)
# --> retval $_natacpi:
# 0=thresholds/
# 32=disabled/
# 128=no kernel support/
# 254=laptop not supported
#
# 2. determine method for
# reading battery data --> retval $_bm_read,
# reading/writing charging thresholds --> retval $_bm_thresh,
# reading/writing force discharge --> retval $_bm_dischg:
# none/natacpi
#
# 3. define sysfile basenames for natacpi
# stop threshold --> retval $_bn_stop,
#
# 4. determine present batteries
# list of batteries (space separated) --> retval $_batteries;
#
# 5. define charge threshold defaults
# stop threshold --> retval $_bt_def_stop;
_batdrv_plugin="framework"
_batdrv_kmod="framework_laptop" # kernel module for natacpi
# check plugin simulation override and denylist
if [ -n "$X_BAT_PLUGIN_SIMULATE" ]; then
if [ "$X_BAT_PLUGIN_SIMULATE" = "$_batdrv_plugin" ]; then
echo_debug "bat" "batdrv_init.${_batdrv_plugin}.simulate"
else
echo_debug "bat" "batdrv_init.${_batdrv_plugin}.simulate_skip"
return 1
fi
elif wordinlist "$_batdrv_plugin" "$X_BAT_PLUGIN_DENYLIST"; then
echo_debug "bat" "batdrv_init.${_batdrv_plugin}.denylist"
return 1
else
# check if hardware matches
if ! batdrv_is_framework; then
echo_debug "bat" "batdrv_init.${_batdrv_plugin}.no_match"
return 1
fi
fi
# presume no features at all
_natacpi=128
# shellcheck disable=SC2034
_bm_read="natacpi"
_bm_thresh="none"
# shellcheck disable=SC2034
_bm_dischg="none"
_bn_stop=""
_batteries=""
# framework doesn't support charge start threshold
_bt_def_stop=60
# iterate batteries and check for native kernel ACPI
local bd bs
local done=0
for bd in "$ACPIBATDIR"/BAT[01]; do
if [ "$(read_sysf "$bd/present")" = "1" ]; then
# record detected batteries and directories
bs=${bd##/*/}
if [ -n "$_batteries" ]; then
_batteries="$_batteries $bs"
else
_batteries="$bs"
fi
# skip natacpi detection for 2nd and subsequent batteries
[ $done -eq 1 ] && continue
done=1
if [ "$NATACPI_ENABLE" = "0" ]; then
# natacpi disabled in configuration --> skip actual detection
_natacpi=32
continue
fi
if [ -f "$bd/charge_control_end_threshold" ]; then
# threshold sysfiles exist
_bn_stop="charge_control_end_threshold"
_natacpi=254
else
# nothing detected
_natacpi=254
continue
fi
if readable_sysf "$bd/$_bn_stop"; then
# threshold sysfiles are actually readable
_natacpi=0
_bm_thresh="natacpi"
fi
fi
done
# quit if no battery detected, there is no point in activating the plugin
if [ -z "$_batteries" ]; then
echo_debug "bat" "batdrv_init.${_batdrv_plugin}.no_batteries"
return 2
fi
# shellcheck disable=SC2034
_batdrv_selected=$_batdrv_plugin
echo_debug "bat" "batdrv_init.${_batdrv_plugin}: batteries=$_batteries; natacpi=$_natacpi; thresh=$_bm_thresh; bn_stop=$_bn_stop;"
return 0
}
batdrv_select_battery () {
# determine battery acpidir and sysfiles
# $1: BAT0/BAT1/DEF
# # rc: 0=bat exists/1=bat non-existent
# retval: $_bat_str: BAT0/BAT1/BATT;
# $_bd_read: directory with battery data sysfiles;
# $_bf_stop: sysfile for stop threshold;
# prerequisite: batdrv_init()
# defaults
_bat_str="" # no bat
_bd_read="" # no directory
_bf_stop=""
# validate battery param
local bs
case $1 in
DEF) # 1st battery is default
_bat_str="${_batteries%% *}"
;;
*)
if wordinlist "$1" "$_batteries"; then
_bat_str=$1
else
# battery not present --> quit
echo_debug "bat" "batdrv.${_batdrv_plugin}.select_battery($1).not_present"
return 1
fi
;;
esac
# determine natacpi sysfiles
_bd_read="$ACPIBATDIR/$_bat_str"
if [ "$_bm_thresh" = "natacpi" ]; then
_bf_stop="$ACPIBATDIR/$_bat_str/$_bn_stop"
fi
echo_debug "bat" "batdrv.${_batdrv_plugin}.select_battery($1): bat_str=$_bat_str; bd_read=$_bd_read; bf_stop=$_bf_stop"
return 0
}
batdrv_read_threshold () {
# read and print charge threshold
# $1: start/stop
# $2: 0=api/1=tlp-stat output
# global param: $_bm_thresh, $_bf_stop
# out:
# - api: 0..100/"" on error
# - tlp-stat: 0..100/"(not available)" on error
# rc: 0=ok/4=read error/255=no api
# prerequisite: batdrv_init(), batdrv_select_battery()
local bf out="" rc=0
case $1 in
start) printf "(not available)\n"; return 0 ;;
stop) out="$X_THRESH_SIMULATE_STOP" ;;
esac
if [ -n "$out" ]; then
printf "%s" "$out"
echo_debug "bat" "batdrv.${_batdrv_plugin}.read_threshold($1).simulate: bm_thresh=$_bm_thresh; bf=$bf; out=$out; rc=$rc"
return 0
fi
if [ "$_bm_thresh" = "natacpi" ]; then
# read threshold from sysfile
case $1 in
stop) bf=$_bf_stop ;;
esac
if ! out=$(read_sysf "$bf"); then
# not readable/non-existent
if [ "$2" != "1" ]; then
out=""
else
out="(not available)"
fi
rc=4
fi
else
# no threshold api
if [ "$2" = "1" ]; then
out="(not available)"
fi
rc=255
fi
# "return" threshold
if [ "$X_THRESH_SIMULATE_READERR" != "1" ]; then
printf "%s" "$out"
else
if [ "$2" = "1" ]; then
printf "(not available)\n"
fi
rc=4
fi
echo_debug "bat" "batdrv.${_batdrv_plugin}.read_threshold($1): bm_thresh=$_bm_thresh; bf=$bf; out=$out; rc=$rc"
return $rc
}
batdrv_write_thresholds () {
# write both charge thresholds for a battery
# use pre-determined method and sysfiles from global parms
# $1: new start threshold 0(disabled)..100/DEF(default)
# $2: new stop threshold 0..100/DEF(default)
# $3: 0=quiet/1=output parameter errors/2=output progress and errors
# $4: config battery - non-empty string indicates thresholds stem from configuration
# global param: $_bm_thresh, $_bat_str, $_bf_stop
# rc: 0=ok/
# 1=not configured/
# 2=threshold(s) out of range or non-numeric/
# 3=minimum start stop diff violated/
# 4=threshold read error/
# 5=threshold write error
# prerequisite: batdrv_init(), batdrv_select_battery()
local new_stop=${2:-}
local verb=${3:-0}
local cfg_bat="$4"
local old_stop
# insert defaults
[ "$new_stop" = "DEF" ] && new_stop=$_bt_def_stop
# --- validate thresholds
local rc
# TEMPLATE: customize boundaries to vendor specs
# stop: check for 3 digits max, ensure min 0 / max 100
if ! is_uint "$new_stop" 3 || \
! is_within_bounds "$new_stop" 0 100; then
# threshold out of range
echo_debug "bat" "batdrv.${_batdrv_plugin}.write_thresholds($1, $2, $3, $4).invalid_stop: bat=$_bat_str"
case $verb in
1)
if [ -n "$cfg_bat" ]; then
echo_message "Error in configuration at STOP_CHARGE_THRESH_${cfg_bat}=\"${new_stop}\": not specified, invalid or out of range (0..100). Battery skipped."
fi
;;
2)
if [ -n "$cfg_bat" ]; then
printf "Error in configuration at STOP_CHARGE_THRESH_%s=\"%s\": not specified, invalid or out of range (0..100). Aborted.\n" "$cfg_bat" "$new_stop" 1>&2
else
printf "Error: stop charge threshold (%s) for %s is not specified, invalid or out of range (0..100). Aborted.\n" "$new_stop" "$_bat_str" 1>&2
fi
;;
esac
return 2
fi
# read active threshold values
if ! old_stop=$(batdrv_read_threshold stop 0); then
echo_debug "bat" "batdrv.${_batdrv_plugin}.write_thresholds($1, $2, $3, $4).read_error: bat=$_bat_str"
case $verb in
1) echo_message "Error: could not read current charge threshold(s) for $_bat_str. Battery skipped." ;;
2) printf "Error: could not read current charge threshold(s) for %s. Aborted.\n" "$_bat_str" 1>&2 ;;
esac
return 4
fi
# TEMPLATE: customize assertion to vendor specs
# determine write sequence too meet boundary condition start < stop
# disclaimer: the driver doesn't enforce it but we don't know about the
# firmware and it's reasonable anyway
local rc=0 steprc tseq="stop"
# write new thresholds in determined sequence
if [ "$verb" = "2" ]; then
printf "Setting temporary charge thresholds for %s:\n" "$_bat_str"
fi
for step in $tseq; do
local old_thresh new_thresh steprc
case $step in
start)
continue
;;
stop)
old_thresh=$old_stop
new_thresh=$new_stop
;;
esac
if [ "$old_thresh" != "$new_thresh" ]; then
# new threshold differs from effective one --> write it
case $step in
stop) write_sysf "$new_thresh" "$_bf_stop" ;;
esac
steprc=$?; [ $steprc -ne 0 ] && rc=5
echo_debug "bat" "batdrv.${_batdrv_plugin}.write_thresholds($1, $2, $3, $4).$step.write: bat=$_bat_str; old=$old_thresh; new=$new_thresh; steprc=$steprc"
case $verb in
2)
if [ $steprc -eq 0 ]; then
printf " %-5s = %3d\n" "$step" "$new_thresh"
else
printf " %-5s = %3d (Error: write failed)\n" "$step" "$new_thresh" 1>&2
fi
;;
1)
if [ $steprc -gt 0 ]; then
echo_message "Error: writing charge $step threshold for $_bat_str failed."
fi
;;
esac
else
echo_debug "bat" "batdrv.${_batdrv_plugin}.write_thresholds($1, $2, $3, $4).$step.no_change: bat=$_bat_str; old=$old_thresh; new=$new_thresh"
if [ "$verb" = "2" ]; then
printf " %-5s = %3d (no change)\n" "$step" "$new_thresh"
fi
fi
done # for step
echo_debug "bat" "batdrv.${_batdrv_plugin}.write_thresholds($1, $2, $3, $4).complete: bat=$_bat_str; rc=$rc"
return $rc
}
batdrv_chargeonce () {
# function not implemented
echo_debug "bat" "batdrv.${_batdrv_plugin}.charge_once.not_implemented"
return 255
}
batdrv_apply_configured_thresholds () {
# apply configured stop thresholds from configuration to all batteries
# output parameter errors only
if batdrv_select_battery BAT0; then
batdrv_write_thresholds 0 "$STOP_CHARGE_THRESH_BAT0" 1 "BAT0"; rc=$?
fi
if batdrv_select_battery BAT1; then
batdrv_write_thresholds 0 "$STOP_CHARGE_THRESH_BAT1" 1 "BAT1"; rc=$?
fi
return 0
}
batdrv_read_force_discharge () {
# function not implemented
echo_debug "bat" "batdrv.${_batdrv_plugin}.read_force_discharge.not_implemented"
return 255
}
batdrv_write_force_discharge () {
# function not implemented
echo_debug "bat" "batdrv.${_batdrv_plugin}.write_force_discharge.not_implemented"
return 255
}
batdrv_cancel_force_discharge () {
# function not implemented
echo_debug "bat" "batdrv.${_batdrv_plugin}.cancel_force_discharge.not_implemented"
return 255
}
batdrv_force_discharge_active () {
# function not implemented
echo_debug "bat" "batdrv.${_batdrv_plugin}.force_discharge_active.not_implemented"
return 255
}
batdrv_discharge () {
# function not implemented
# Important: release lock from caller
unlock_tlp tlp_discharge
echo_debug "bat" "batdrv.${_batdrv_plugin}.discharge.not_implemented"
return 255
}
batdrv_show_battery_data () {
# output battery status
# $1: 1=verbose
# global param: $_batteries
# prerequisite: batdrv_init()
local verbose=${1:-0}
printf "+++ Battery Care\n"
printf "Plugin: %s\n" "$_batdrv_plugin"
if [ "$_bm_thresh" != "none" ]; then
printf "Supported features: charge thresholds\n"
else
printf "Supported features: none available\n"
fi
printf "Driver usage:\n"
# native kernel ACPI battery API
case $_natacpi in
0) printf "* natacpi (%s) = active (charge thresholds)\n" "$_batdrv_kmod" ;;
32) printf "* natacpi (%s) = inactive (disabled by configuration)\n" "$_batdrv_kmod" ;;
128) printf "* natacpi (%s) = inactive (no kernel support)\n" "$_batdrv_kmod" ;;
254) printf "* natacpi (%s) = inactive (laptop not supported)\n" "$_batdrv_kmod" ;;
*) printf "* natacpi (%s) = unknown status\n" "$_batdrv_kmod" ;;
esac
# TEMPLATE: customize to vendor specs
if [ "$_bm_thresh" != "none" ]; then
printf "Parameter value ranges:\n"
printf "* START_CHARGE_THRESH_BAT1/1: 0 (not available)\n"
printf "* STOP_CHARGE_THRESH_BAT1/1: 0..100(default)\n"
fi
printf "\n"
# -- show battery data
local bat
local bcnt=0
local ed ef en
local efsum=0
local ensum=0
for bat in $_batteries; do # iterate batteries
batdrv_select_battery "$bat"
printf "+++ Battery Status: %s\n" "$bat"
printparm "%-59s = ##%s##" "$_bd_read/serial_number"
print_battery_cycle_count "$_bd_read/cycle_count" "$(read_sysf "$_bd_read/cycle_count")"
if [ -f "$_bd_read/energy_full" ]; then
printparm "%-59s = ##%6d## [mWh]" "$_bd_read/energy_full_design" "" 000
printparm "%-59s = ##%6d## [mWh]" "$_bd_read/energy_full" "" 000
printparm "%-59s = ##%6d## [mWh]" "$_bd_read/energy_now" "" 000
printparm "%-59s = ##%6d## [mW]" "$_bd_read/power_now" "" 000
# store values for charge / capacity calculation below
ed=$(read_sysval "$_bd_read/energy_full_design")
ef=$(read_sysval "$_bd_read/energy_full")
en=$(read_sysval "$_bd_read/energy_now")
efsum=$((efsum + ef))
ensum=$((ensum + en))
elif [ -f "$_bd_read/charge_full" ]; then
printparm "%-59s = ##%6d## [mAh]" "$_bd_read/charge_full_design" "" 000
printparm "%-59s = ##%6d## [mAh]" "$_bd_read/charge_full" "" 000
printparm "%-59s = ##%6d## [mAh]" "$_bd_read/charge_now" "" 000
printparm "%-59s = ##%6d## [mA]" "$_bd_read/current_now" "" 000
# store values for charge / capacity calculation below
ed=$(read_sysval "$_bd_read/charge_full_design")
ef=$(read_sysval "$_bd_read/charge_full")
en=$(read_sysval "$_bd_read/charge_now")
efsum=$((efsum + ef))
ensum=$((ensum + en))
else
ed=0
ef=0
en=0
fi
print_batstate "$_bd_read/status"
printf "\n"
if [ "$verbose" -eq 1 ]; then
printparm "%-59s = ##%6s## [mV]" "$_bd_read/voltage_min_design" "" 000
printparm "%-59s = ##%6s## [mV]" "$_bd_read/voltage_now" "" 000
printf "\n"
fi
# --- show battery features: thresholds
if [ "$_bm_thresh" = "natacpi" ]; then
printf "%-59s = %6s [%%]\n" "$_bf_stop" "$(batdrv_read_threshold stop 1)"
printf "\n"
fi
# --- show charge level (SOC) and capacity
lf=0
if [ "$ef" -ne 0 ]; then
perl -e 'printf ("%-59s = %6.1f [%%]\n", "Charge", 100.0 * '"$en"' / '"$ef"');'
lf=1
fi
if [ "$ed" -ne 0 ]; then
perl -e 'printf ("%-59s = %6.1f [%%]\n", "Capacity", 100.0 * '"$ef"' / '"$ed"');'
lf=1
fi
[ "$lf" -gt 0 ] && printf "\n"
bcnt=$((bcnt+1))
done # for bat
if [ $bcnt -gt 1 ] && [ $efsum -ne 0 ]; then
# more than one battery detected --> show charge total
perl -e 'printf ("%-59s = %6.1f [%%]\n", "+++ Charge total", 100.0 * '"$ensum"' / '"$efsum"');'
printf "\n"
fi
return 0
}
batdrv_recommendations () {
# no recommendations
return 0
}
As a general rule, we want folks to do battery charge limiting in the BIOS settings. This is what we are actively supporting.
Is there a specific reason why? Just so it’s guaranteed to be set w/out booting is my guess?
Yep, because when it doesn’t work as expected, folks then seek support for something I have not tested/blessed in testing. 
Those comfortable doing so (engineers, etc) that understand the ins and outs are of course going to do what they think is best for their use case scenarios. But I do not have the cycles to supported in my own scope.