ublox-gnss-config: split from gpsd layer, renamed, improved

Changes to baud rate config script:
+ more appropriate name
+ only one service
+ baud rate detector is faster in special case
+ shellcheck conform
- no longer creates default config file if file is missing, instead
throws error

BugzID: 60698

Signed-off-by: Tobias Jäggi <tobias.jaeggi@netmodule.com>

recipes-connectivity/gpsd/config-gnss-tty.bb

@@ -1,32 +0,0 @@
-# Copyright (C) 2020 Tobias Jäggi <tobias.jaeggi@netmodule.com>
-# Released under the MIT license (see COPYING.MIT for the terms)
-DESCRIPTION = "ttyS3 config service"
-HOMEPAGE = "www.netmodule.com"
-LICENSE = "MIT"
-SECTION = "bsp/firmware"
-LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"
-
-
-inherit systemd
-
-SRC_URI = " \ 
-           file://config-gnss-tty.service \
-           file://config-gnss-tty.sh \
-           "
-
-S = "${WORKDIR}"
-
-SYSTEMD_SERVICE_${PN} = " \
-                          config-gnss-tty.service \
-                        "
-
-FILES_${PN} = "${systemd_unitdir}/system ${bindir}"
-
-do_install() {
-    install -d ${D}${systemd_unitdir}/system
-    install -m 644 ${WORKDIR}/config-gnss-tty.service ${D}${systemd_unitdir}/system/
-
-    install -d ${D}${bindir}
-    install -m 744 ${WORKDIR}/config-gnss-tty.sh ${D}${bindir}/config-gnss-tty
-
-}

recipes-connectivity/gpsd/files/config-gnss-receiver.service

@@ -1,12 +0,0 @@
-[Unit]
-Description=config baud rate on NEO-M8L
-Before=config-gnss-tty.service
-
-[Service]
-
-Type=oneshot
-ExecStart=/usr/bin/config-gnss-receiver
-RemainAfterExit=no
-
-[Install]
-WantedBy=multi-user.target

recipes-connectivity/gpsd/files/config-gnss-tty.service

@@ -1,12 +0,0 @@
-[Unit]
-Description=config baud rate of tty used by gnss receiver
-Before=gpsd.service
-
-[Service]
-
-Type=oneshot
-ExecStart=/usr/bin/config-gnss-tty
-RemainAfterExit=no
-
-[Install]
-WantedBy=multi-user.target

recipes-connectivity/gpsd/files/config-gnss-tty.sh

@@ -1,33 +0,0 @@
-#!/bin/sh
-
-# exit codes:
-# 0: success
-# 1: $CONFIG_FILE is missing (should have been created by config-gnss-receiver)
-# 2: failed to set baud rate of $TTY_INTERFACE to $DESIRED_BAUD_RATE
-
-TTY_INTERFACE="/dev/ttyS3"
-CONFIG_FILE="/etc/gnss.conf"
-
-# check if CONFIG_FILE exists
-if ! test -f "$CONFIG_FILE"; then
-  # CONFIG_FILE doesn't exist
-  printf "config file missing\n"
-  exit 1 # $CONFIG_FILE is missing (should have been created by config-gnss-receiver)
-fi
-
-# read $DESIRED_BAUD_RATE specified in $CONFIG_FILE
-read -r DESIRED_BAUD_RATE <<< "$(awk '/br=(\d*)/{print $0}' < $CONFIG_FILE)"
-read -r DESIRED_BAUD_RATE <<< "$(echo "$DESIRED_BAUD_RATE" | cut -d'=' -f 2)"
-
-# set baud rate
-stty -F "$TTY_INTERFACE" speed "$DESIRED_BAUD_RATE" > /dev/null
-
-# verify baud rate
-read -r TTYS3_BAUD_RATE <<< "$(stty -F "$TTY_INTERFACE" | awk '/speed .* baud;/{print $2}')"
-if [ "$TTYS3_BAUD_RATE" == "$DESIRED_BAUD_RATE" ];then
-  printf "successfully set baud rate of %s to %s baud\n" "$TTY_INTERFACE" "$DESIRED_BAUD_RATE"
-  exit 0 # success
-else
-  printf "failed to set baud rate of %s to %s\n" "$TTY_INTERFACE" "$DESIRED_BAUD_RATE"
-  exit 2
-fi

recipes-connectivity/ublox-gnss-config/files/ublox-gnss-config.service

@@ -0,0 +1,12 @@
+[Unit]
+Description=config baud rate on NEO-M8L and relevant tty interface
+Before=gpsd.service
+
+[Service]
+
+Type=oneshot
+ExecStart=/usr/bin/ublox-gnss-config
+RemainAfterExit=yes
+
+[Install]
+WantedBy=multi-user.target

recipes-connectivity/ublox-gnss-config/files/ublox-gnss-config.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 # This script tries to figure out the baud rate of $DEVICE_NAME connected to $TTY_INTERFACE.
 # If the script successfully determines the baud rate of the receiver,
@@ -7,19 +7,19 @@
 
 # exit codes:
 # 0 success
-# 1 unable to detect baud rate
+# 1 unable to detect baud rate of receiver
-# 2 set baud rate was not successful
+# 2 config file missing
-# 3 baud rate not set to $DESIRED_BAUD_RATE or verifiying baud rate failed
+# 3 reciever baud rate not set to $DESIRED_BAUD_RATE or verifiying baud rate failed
 # 4 saving to flash failed
 # 5 baud rate specified in $CONFIG_FILE not supported by $DEVICE_NAME
+# 6 set tty baud rate was not successful
 
 # static variables
 DEVICE_NAME="NEO-M8L"
 TTY_INTERFACE="/dev/ttyS3"
 CONFIG_FILE="/etc/gnss.conf"
 SAVE_FILE="/var/gnss-receiver-save-state"
-# if the config file is missing, a new one gets created with $DEFAULT_BAUD_RATE baud
+
-DEFAULT_BAUD_RATE=115200
 # first baud rate in PRESELECTION_BAUD_RATES should be the one which is most likely the current baud rate of the GNSS receiver,
 # the last one should be the one least likely used by the reciever.
 # This can reduce the runtime of this script
@@ -82,8 +82,8 @@ detect_baud_rate () {
   local _polled_baud_rate
   for br in "${_baud_rates[@]}";
     do
-      printf "testing %s baud\n" "$br"
+      printf "testing %s baud\\n" "$br"
-        for i in $(eval echo {1.."$_allowed_retries"})
+        for i in $(eval "echo {1..$_allowed_retries}")
         do
           _polled_baud_rate="$(poll_baud_rate_receiver "$br")"
           if [ "$_polled_baud_rate" == "0" ];then
@@ -95,10 +95,10 @@ detect_baud_rate () {
             return 0
           fi
         done
-      printf "no luck so far\n"
+      printf "no luck so far\\n"
   done
 # failed to detect baud rate
-printf "failed to detect baud rate\n"
+printf "failed to detect baud rate\\n"
 return 1
 }
 
@@ -115,6 +115,18 @@ save_receiver_config () {
   return 1
 }
 
+set_baud_rate_tty () {
+  # set baud rate of $TTY_INTERFACE
+  stty -F "$TTY_INTERFACE" speed "$DESIRED_BAUD_RATE" > /dev/null
+  # verify baud rate
+  read -r TTYS3_BAUD_RATE <<< "$(stty -F "$TTY_INTERFACE" | awk '/speed .* baud;/{print $2}')"
+  if [ "$TTYS3_BAUD_RATE" == "$DESIRED_BAUD_RATE" ];then
+    return 0
+  else
+    # baud rate configured on $TTY_INTERFACE is not matching baud rate specified in $CONFIG_FILE
+    return 1
+  fi
+}
 # start of main
 
 # check if script was launched by systemd
@@ -127,24 +139,26 @@ else
   RESTART_GPSD=0
 fi
 
+# TODO: remove this hack in favour of a proper python environment
+# hack to get pyserial working
+PYTHONPATH=/usr/lib/python3.7/site-packages/ && export PYTHONPATH
+
 # TODO: parse input args to display help which would explain usage of $CONFIG_FILE
 
 # check if CONFIG_FILE exists
 if ! test -f "$CONFIG_FILE"; then
   # CONFIG_FILE doesn't exist
-  printf "config file missing\n"
+  printf "config file missing\\n"
-  touch $CONFIG_FILE
+  exit 2
-  echo -e "#\n# Define a baud rate to be used by the GNSS receiver\n# This file is part of ublox-gnss-config service\n#\n# Required fields:\n#     br:       baud rate to be used by the GNSS receiver\n#\n\n\n[default]\nbr=$DEFAULT_BAUD_RATE\n" > $CONFIG_FILE
-  printf "created default config file %s with %s baud\n" "$CONFIG_FILE" "$DEFAULT_BAUD_RATE"
 fi
 
 # check if SAVE_FILE exists
 if ! test -f "$SAVE_FILE"; then
   # SAVE_FILE doesn't exist
-  printf "save file missing\n"
+  printf "save file missing\\n"
   touch $SAVE_FILE
   echo 0 > $SAVE_FILE
-  printf "created save file %s\n" "$SAVE_FILE"
+  printf "created save file %s\\n" "$SAVE_FILE"
 fi
 
 # read $DESIRED_BAUD_RATE specified in $CONFIG_FILE
@@ -161,13 +175,13 @@ do
   fi
 done
 if [ "$baud_rate_supported_flag" == "0" ];then
-  printf "baud rate specified in %s is not supported by receiver %s\n" "$CONFIG_FILE" "$DEVICE_NAME"
+  printf "baud rate specified in %s is not supported by receiver %s\\n" "$CONFIG_FILE" "$DEVICE_NAME"
-  printf "supported baud rates are:\n"
+  printf "supported baud rates are:\\n"
   for j in "${SUPPORTED_BAUD_RATES[@]}"
   do
     printf "%s " "$j"
   done
-  printf "\n"
+  printf "\\n"
   exit 5 # baud rate specified in $CONFIG_FILE not supported by $DEVICE_NAME
 fi
 
@@ -177,20 +191,30 @@ if br_receiver="$(poll_baud_rate_receiver "$DESIRED_BAUD_RATE")";then
   if [ "$br_receiver" == "$DESIRED_BAUD_RATE" ];then
     # baud rate of receiver is matching baud rate specified in CONFIG_FILE
     if [ "$(cat "$SAVE_FILE")" == "1" ];then
-      printf "baud rate of %s is already at %s baud\n" "$DEVICE_NAME" "$DESIRED_BAUD_RATE"
+      printf "baud rate of %s is already at %s baud\\n" "$DEVICE_NAME" "$DESIRED_BAUD_RATE"
-      printf "configuration is saved in flash of %s\n" "$DEVICE_NAME"
+      printf "configuration is saved in flash of %s\\n" "$DEVICE_NAME"
+
+      if set_baud_rate_tty;then
+        printf "set baud rate of %s to %s baud\\n" "$TTY_INTERFACE" "$DESIRED_BAUD_RATE"
+      else
+        printf "failed to set baud rate of %s to %s\\n" "$TTY_INTERFACE" "$DESIRED_BAUD_RATE"
+        exit 6
+      fi
+
       # script can exit
       exit 0 # baud rate of receiver is already matching $DESIRED_BAUD_RATE
     else
       # TODO: this could be way faster by telling the detector which baud rate to use since we already know it
-      printf "baud rate of %s is already at %s baud\n" "$DEVICE_NAME" "$DESIRED_BAUD_RATE"
+      printf "baud rate of %s is already at %s baud\\n" "$DEVICE_NAME" "$DESIRED_BAUD_RATE"
-      printf "configuration is not saved in flash of %s\n" "$DEVICE_NAME"
+      printf "configuration is not saved in flash of %s\\n" "$DEVICE_NAME"
+      # hint for the detector
+      PRESELECTION_BAUD_RATES=("$br_receiver")
     fi
   else
-    printf "baud rates are not matching\n"
+    printf "baud rates are not matching\\n"
   fi
 else
-  printf "read failed\n"
+  printf "read failed\\n"
 fi
 
 # determine current baud rate of receiver
@@ -198,20 +222,20 @@ args=("2" "${PRESELECTION_BAUD_RATES[@]}")
 detect_baud_rate "${args[@]}"
 if [ "$?" == "1" ];then
   # retry with more baud rates and more tries per baud rate
-  printf "retrying\n"
+  printf "retrying\\n"
   # maybe a time out increase would also work when dealing with lower baud rates?
   args=("$MAX_ALLOWED_RETRIES" "${SUPPORTED_BAUD_RATES[@]}")
   detect_baud_rate "${args[@]}"
   if [ "$?" == "1" ];then
-    printf "baud rate not detected, even after retry\n"
+    printf "baud rate not detected, even after retry\\n"
     exit 1 # unable to detect baud rate
   fi
 fi
-printf "detected baud rate of %s is %s baud\n" "$DEVICE_NAME" "$DETECTED_BAUD_RATE"
+printf "detected baud rate of %s is %s baud\\n" "$DEVICE_NAME" "$DETECTED_BAUD_RATE"
 
 # upgrade to $DESIRED_BAUD_RATE baud
 new_baud_rate_set_flag=0
-for i in $(eval echo {0.."$MAX_ALLOWED_RETRIES"})
+for i in $(eval "echo {0..$MAX_ALLOWED_RETRIES}")
 do
   set_baud_rate_receiver "$DETECTED_BAUD_RATE" "$DESIRED_BAUD_RATE"
 
@@ -231,15 +255,15 @@ do
 done
 
 if [ "$new_baud_rate_set_flag" == "0" ];then
-  printf "baud rate of %s is not set to %s baud or unable to verify, retried %s times\n" "$DEVICE_NAME" "$DESIRED_BAUD_RATE" "$i"
+  printf "baud rate of %s is not set to %s baud or unable to verify, retried %s times\\n" "$DEVICE_NAME" "$DESIRED_BAUD_RATE" "$i"
   exit 3 # baud rate not set to $DESIRED_BAUD_RATE or verifiying baud rate failed
 else
-  printf "baud rate of %s is set to desired %s baud, it took %s retries\n" "$DEVICE_NAME" "$DESIRED_BAUD_RATE" "$i"
+  printf "baud rate of %s is set to desired %s baud, it took %s retries\\n" "$DEVICE_NAME" "$DESIRED_BAUD_RATE" "$i"
 fi
 
 # save config to flash
 config_saved_flag=0
-for i in $(eval echo {0.."$MAX_ALLOWED_RETRIES"})
+for i in $(eval "echo {0..$MAX_ALLOWED_RETRIES}")
 do
   if save_receiver_config;then
     config_saved_flag=1
@@ -251,15 +275,21 @@ do
 done
 
 if [ "$config_saved_flag" == "0" ];then
-  printf "saving to flash was not successful, retried %s times\n" "$i"
+  printf "saving to flash was not successful, retried %s times\\n" "$i"
   exit 4 # saving to flash failed
 else
-  printf "saving to flash was successful, it took %s retries\n" "$i"
+  printf "saving to flash was successful, it took %s retries\\n" "$i"
+fi
+
+if set_baud_rate_tty;then
+  printf "set baud rate of %s to %s baud\\n" "$TTY_INTERFACE" "$DESIRED_BAUD_RATE"
+else
+  printf "failed to set baud rate of %s to %s\\n" "$TTY_INTERFACE" "$DESIRED_BAUD_RATE"
+  exit 6
 fi
 
 # TODO: verify or error handling
 if [ "$RESTART_GPSD" -eq "1" ]; then
-  config-gnss-tty # call config-gnss-tty to set baud rate of ttyS3 to the baud rate specified in $CONFIG_FILE before launching gpsd
   systemctl start gpsd
 fi
 

recipes-connectivity/ublox-gnss-config/ublox-gnss-config.bb

@@ -9,8 +9,8 @@ LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda
 inherit systemd
 
 SRC_URI = " \
-           file://config-gnss-receiver.service \
+           file://ublox-gnss-config.service \
-           file://config-gnss-receiver.sh \
+           file://ublox-gnss-config.sh \
            file://gnss.conf \
            file://gnss-receiver-save-state \
            "
@@ -18,17 +18,17 @@ SRC_URI = " \
 S = "${WORKDIR}"
 
 SYSTEMD_SERVICE_${PN} = " \
-                          config-gnss-receiver.service \
+                          ublox-gnss-config.service \
                         "
 
 FILES_${PN} = "${systemd_unitdir}/system ${bindir} ${localstatedir} ${sysconfdir}"
 
 do_install() {
     install -d ${D}${systemd_unitdir}/system
-    install -m 644 ${WORKDIR}/config-gnss-receiver.service ${D}${systemd_unitdir}/system/
+    install -m 644 ${WORKDIR}/ublox-gnss-config.service ${D}${systemd_unitdir}/system/
 
     install -d ${D}${bindir}
-    install -m 744 ${WORKDIR}/config-gnss-receiver.sh ${D}${bindir}/config-gnss-receiver
+    install -m 744 ${WORKDIR}/ublox-gnss-config.sh ${D}${bindir}/ublox-gnss-config
    
     install -d ${D}${sysconfdir}
     install -m 644 ${WORKDIR}/gnss.conf ${D}${sysconfdir}/gnss.conf
@@ -37,4 +37,6 @@ do_install() {
     install -m 644 ${WORKDIR}/gnss-receiver-save-state ${D}${localstatedir}/gnss-receiver-save-state
 }
 
-RDEPENDS_${PN} = "gpsd"
+RDEPENDS_${PN} = "gpsd \
+		  bash \
+		 "