Added search feature to GPIO command

general/overlay/usr/sbin/gpio

@@ -1,18 +1,26 @@
 #!/bin/sh
 
 help() {
-    echo "gpio <set|clear|toggle> <pin>"
+    echo -e "\n=== GPIO usage ===\n"
-    echo "gpio <unexport|release> <pin>"
+
-    echo "gpio read <pin>"
+    echo -e ">\t gpio <set|clear|toggle|unexport|read> <pin>\n"
+    echo -e "set\t\t = Output HI\nclear\t\t = Output LOW\ntoggle\t\t = Swap HI <> LOW\nunexport\t = Release GPIO pin back to the kernel space\nread\t\t = Read GPIO pin output state\n"
+    
+    echo -e "---\n"
+
+    echo -e ">\t gpio search <from pin> <to pin>\n"
+    echo -e "Toggle a range of GPIO pins from HI to LOW"
+    echo -e "gpio search logs to syslog\n"
+
+    echo -e "==================\n"
 }
 
 exp() {
     if [ ! -d /sys/class/gpio/gpio$1 ]; then
+        [ ! -f /sys/class/gpio/export ] && echo "Error: No export file!" && exit
         echo $1 > /sys/class/gpio/export
+        [ ! -f /sys/class/gpio/gpio$1/direction ] && echo "Error: No direction file!" && exit
         echo out > /sys/class/gpio/gpio$1/direction
-    elif [ $(cat /sys/class/gpio/gpio$1/direction) = "in" ]; then
-        echo Pin $1 is currently configured as input. Be careful!
-        exit 0
     fi
 }
 
@@ -21,37 +29,57 @@ write(){
 }
 
 read() {
+    [ ! -f /sys/class/gpio/gpio$1/value ] && echo "Error: GPIO-$1 is not set" && exit
     echo $(cat /sys/class/gpio/gpio$1/value)
 }
 
 unexport() {
     if [ -d /sys/class/gpio/gpio$1 ]; then
         echo $1 > /sys/class/gpio/unexport
+    else
+        echo "GPIO-${1} is not exported."
     fi
 }
 
+search() {
+    echo -e "Start blink (output) on GPIO range $1 to $2\n"
+    for pin in $(seq $1 $2); do
+        echo "================================="
+        exp ${pin} && echo "  Exported GPIO-${pin} from kernel space" && echo "    Set GPIO-${pin} to OUTPUT mode"
+        write 0 ${pin} && echo "      Set GPIO-${pin} to LO level" ; sleep 1
+        write 1 ${pin} && echo "      Set GPIO-${pin} to HI level" ; sleep 1
+        echo in > /sys/class/gpio/gpio${pin}/direction && echo "    Set GPIO-${pin} to INPUT mode"
+        unexport ${pin} && echo "  Unexported GPIO-${pin}"
+        logger HELLO - ${pin}
+    done
+}
+
 if [ -n $1 ] && [ -n $2 ] && [ $2 -eq $2 ]; then
         case $1 in
             set)
                 exp $2
+                echo "Setting GPIO-$2 to HI"
                 write 1 $2
                 ;;
 
             clear)
                 exp $2
+                echo "Setting GPIO-$2 to LOW"
                 write 0 $2
                 ;;
 
             toggle)
                 exp $2
-                if [ read -eq 0 ]; then
+                if [ $(read $2) -eq 0 ]; then
+                    echo "Setting GPIO-$2 to HI"
                     write 1 $2
                 else
+                    echo "Setting GPIO-$2 to LOW"
                     write 0 $2
                 fi
                 ;;
 
-            unexport|release)
+            unexport)
                 unexport $2
                 ;;
 
@@ -59,10 +87,19 @@ if [ -n $1 ] && [ -n $2 ] && [ $2 -eq $2 ]; then
                 echo $(read $2)
                 ;;
 
+            search)
+                if [ ! -z $3 ] && [ $3 -eq $3 ]; then
+                    search $2 $3
+                else
+                    echo -e "\n Caution: Toggling single pin. Use <gpio search <from pin> <to pin> to search a range.\n"
+                    search $2 $2
+                fi
+            ;;
+
             *)  
                 help
                 ;;
         esac
 else
     help
-fi
+fi