new post: backlight freebsd (xbl)

content/posts/2023-05-28-backlight-control-on-a-lenovo-x1-carbon/index.md

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+# vim: ft=markdown
+title = 'Backlight control on a Lenovo X1 Carbon'
+summary = '''These two scripts let the X1 switch to a predefined setting for
+battery or ac mode. It also remembers the last used setting for either mode.'''
+date = '2023-05-28T17:35:45+02:00'
+# lastmod = ''
+categories = [ 'computerstuff' ]
+tags = [ 'freebsd', 'script' ]
+
++++
+
+I like to have my computer reduce the screen brightness when it's not
+connected to an external power source.
+
+## powersave.sh
+
+This is (mainly) used to control Intel SpeedStep®. I tend to save my custom
+applications and scripts in `$HOME/bin`. Saved as `$HOME/bin/powersave.sh`.
+
+```sh
+#! /bin/sh
+
+case $( sysctl -n hw.acpi.acline ) in
+
+  (0) # BATTERY
+    doas sysctl dev.hwpstate_intel.0.epp=100 1> /dev/null 2> /dev/null
+    doas sysctl dev.hwpstate_intel.1.epp=100 1> /dev/null 2> /dev/null
+    doas sysctl dev.hwpstate_intel.2.epp=100 1> /dev/null 2> /dev/null
+    doas sysctl dev.hwpstate_intel.3.epp=100 1> /dev/null 2> /dev/null
+    doas sysctl dev.hwpstate_intel.4.epp=100 1> /dev/null 2> /dev/null
+    doas sysctl dev.hwpstate_intel.5.epp=100 1> /dev/null 2> /dev/null
+    doas sysctl dev.hwpstate_intel.6.epp=100 1> /dev/null 2> /dev/null
+    doas sysctl dev.hwpstate_intel.7.epp=100 1> /dev/null 2> /dev/null
+    #backlight 20 1> /dev/null 2> /dev/null
+    backlight $(cat ${HOME}/.backlight-bat) 1> /dev/null 2> /dev/null
+    ;;
+
+  (1) # AC
+    doas sysctl dev.hwpstate_intel.0.epp=0   1> /dev/null 2> /dev/null
+    doas sysctl dev.hwpstate_intel.1.epp=50  1> /dev/null 2> /dev/null
+    doas sysctl dev.hwpstate_intel.2.epp=100 1> /dev/null 2> /dev/null
+    doas sysctl dev.hwpstate_intel.3.epp=100 1> /dev/null 2> /dev/null
+    doas sysctl dev.hwpstate_intel.4.epp=100 1> /dev/null 2> /dev/null
+    doas sysctl dev.hwpstate_intel.5.epp=100 1> /dev/null 2> /dev/null
+    doas sysctl dev.hwpstate_intel.6.epp=100 1> /dev/null 2> /dev/null
+    doas sysctl dev.hwpstate_intel.7.epp=100 1> /dev/null 2> /dev/null
+    #backlight 100 1> /dev/null 2> /dev/null
+    backlight $(cat ${HOME}/.backlight-ac) 1> /dev/null 2> /dev/null
+    ;;
+
+esac
+```
+
+## xbl
+
+A script to modify different backlight settings depending on the connected
+power source. Saved as `$HOME/bin/xbl`.
+
+```sh
+#! /bin/sh
+
+print_usage () {
+  echo >&2 "usage: $(basename ${0}) [0..100]"
+  exit 1
+}
+
+# check if argument given or not (list or set value)
+if [ $# -eq 1 ]
+then
+  # set value (select between ac or bat mode)
+  # check if argument is integer between 0,100
+  if [ "$1" -eq "$1" ] 2>/dev/null
+  then
+    if [ "$1" -ge 0 ] && [ "$1" -le 100 ] 2>/dev/null
+    then
+      # argument given and between 0,100
+      case $( sysctl -n hw.acpi.acline ) in
+        (0) # BATTERY
+          echo "$1" > ${HOME}/.backlight-bat
+          ;;
+        (1) # AC
+          echo "$1" > ${HOME}/.backlight-ac
+          ;;
+      esac
+      backlight "$1"
+    else
+      # arg not between 0 and 100
+      print_usage
+    fi
+  else
+    # arg not an integer
+    print_usage
+  fi
+else
+  # no args given, only list values
+  case $( sysctl -n hw.acpi.acline ) in
+    (0) # BATTERY
+      current=bat
+      ;;
+    (1) # AC
+      current=ac
+      ;;
+  esac
+
+  for status in ac bat
+  do
+    if [ "${status}" = "${current}" ]
+    then
+      echo -e "${status}: ★ \t$( cat ${HOME}/.backlight-${status} )" | tr "[:lower:]" "[:upper:]"
+    else
+      echo -e "${status}:\t$( cat ${HOME}/.backlight-${status} )" | tr "[:lower:]" "[:upper:]"
+    fi
+  done
+fi
+```
+
+