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--- en:acc:vu8 [2017/01/19 10:44]
joy.cho [2. Backlight ON/OFF.]
+++ en:acc:vu8 [2017/01/19 14:18]
joy.cho [3. Backlight control with PWM.]
@@ Line 90: / Line 90: @@
 </code>
-Add "vu8c backlight control" part in "/init.odroid.board.rc" as following.
+Make or download the following shell script of the board model that you're using (C1 or C2)\\
+and copy it in **/system/bin/**.\\
+And make its permission executable.
-**ODROID-C2**
 <code>
-....
+# su
-.....
+# chmod 755 /system/bin/vu8c_backlight_c2_android.sh
-on boot
+</code>
-    setprop ro.radio.noril true
-    write /sys/class/freq_limit/limit 0
-    write /sys/devices/system/cpu/cpu0/cpufreq/scaling_dflt_freq 1536000
-# Permissions for bluetooth$
+**ODROID-C2**
-    setprop ro.bt.bdaddr_path "/efs/bluetooth/bt_addr"$
+<file sh vu8c_backlight_c2_android.sh>
-    chown bluetooth bluetooth ro.bt.bdaddr_path$
+#!/bin/sh
-# vu8c backlight control
+path="/sys/class/gpio"
-    echo 234 > /sys/class/gpio/export
-    echo 214 > /sys/class/gpio/export
+echo 234 > $path/export
-    echo out > /sys/class/gpio/gpio234/direction
+echo 214 > $path/export
-    echo out > /sys/class/gpio/gpio214/direction
-    echo 0 > /sys/class/gpio/gpio234/value
+echo out > $path/gpio234/direction
-    echo 0 > /sys/class/gpio/gpio214/value
+echo out > $path/gpio214/direction
+echo 0 > $path/gpio234/value
+echo 0 > $path/gpio214/value
+chown system system $path/gpio234/value
+chown system system $path/gpio214/value
+</file>
+Now, you need to register the service to run this script automatically on boot time.\\
+Add the following lines in the end of /init.odroid.board.rc.\\
+Don't forget the root filesystem should be writable as aforementioned.
+<code>
+# su
+# vi /init.odroid.board.rc
 .....
 .....
+service vu8c_backlight /system/bin/vu8c_backlight_c2_android.sh
+    class main
+    user root
+    group root
+    oneshot
 </code>
-Then, **reboot**.
+Then, reboot.
 <code>
 $ reboot
@@ Line 131: / Line 147: @@
 </code>
+**ODROID-C1**
+<file sh vu8c_backlight_c1_android.sh>
+#!/bin/sh
+path="/sys/class/gpio"
+echo 97 > $path/export
+echo 108 > $path/export
+echo out > $path/gpio97/direction
+echo out > $path/gpio108/direction
+echo 0 > $path/gpio97/value
+echo 0 > $path/gpio108/value
+chown system system $path/gpio97/value
+chown system system $path/gpio108/value
+</file>
+Now, you need to register the service to run this script automatically on boot time.\\
+Add the following lines in the end of /init.odroid.board.rc.\\
+Don't forget the root filesystem should be writable as aforementioned.
-**ODROID-C1**
 <code>
+# su
+# vi /init.odroid.board.rc
 .....
 .....
-on boot
+service vu8c_backlight /system/bin/vu8c_backlight_c2_android.sh
-    write /sys/class/freq_limit/limit 0
+    class main
-.....
+    user root
-.....
+    group root
-#add for mali scaling mode set
+    oneshot
-    chown system /sys/module/mali/parameters/scaling_mode
+</code>
+Then, reboot.
-# vu8c backlight control
+<code>
-    echo 97 > /sys/class/gpio/export
+$ reboot
-    echo 108 > /sys/class/gpio/export
+</code>
-    echo out > /sys/class/gpio/gpio97/direction
+After reboot, you can confirm if the nodes are configured normally by checking "gpio97" and "gpio108".
-    echo out > /sys/class/gpio/gpio108/direction
+<code>
-    echo 0 > /sys/class/gpio/gpio97/value
+$ ls /sys/class/gpio/
-    echo 0 > /sys/class/gpio/gpio108/value
+export
-.....
+gpio97
-.....
+gpio108
+......
+......
+unexport
 </code>
 ==== 3. Backlight control with PWM. ====
 === GPIO configuration ===
 == ODROID-C2 ==
-  cd /sys/class/gpio
+<code>
-  echo 214 | sudo tee export
+cd /sys/class/gpio
-  echo out | sudo tee gpio214/direction
+echo 214 | sudo tee export
-  echo 0 | sudo tee gpio214/value
+echo out | sudo tee gpio214/direction
-  echo 234 | sudo tee unexport
+echo 0 | sudo tee gpio214/value
+echo 234 | sudo tee unexport
+</code>
 == ODROID-C1+/C1/C0 ==
-  cd /sys/class/gpio
+<code>
-  echo 97 | sudo tee export
+cd /sys/class/gpio
-  echo out | sudo tee gpio97/direction
+echo 97 | sudo tee export
-  echo 0 | sudo tee gpio97/value
+echo out | sudo tee gpio97/direction
-  echo 108 | sudo tee unexport
+echo 0 | sudo tee gpio97/value
+echo 108 | sudo tee unexport
+</code>
 === PWM configuration ===
+== [Ubuntu] ==
 Load PWM driver modules.
-  sudo modprobe pwm-meson
+<code>
-  sudo modprobe pwm-ctrl
+sudo modprobe pwm-meson
-Ignore warning message of "pwm-ctrl pwm-ctrl: cannot export to PWM-1 : modprobe pwm-meson npwm=2"
+sudo modprobe pwm-ctrl
+</code>
+Ignore warning message of "pwm-ctrl pwm-ctrl: cannot export to PWM-1 : modprobe pwm-meson npwm=2" \\
+Enable PWM via sysfs. \\
+<code>
+echo 100000 | sudo tee /sys/devices/platform/pwm-ctrl/freq0
+echo 1 | sudo tee /sys/devices/platform/pwm-ctrl/enable0
+</code>
+Set duty ratio (value can be 0 to 1023. Lower is brighter)
+<code>
+echo 1023 | sudo tee /sys/devices/platform/pwm-ctrl/duty0
+</code>
+== [Android] ==
+Load PWM driver modules.
+<code>
+root@odroidc2:/ # insmod /system/lib/modules/pwm-meson.ko npwm="1"
+root@odroidc2:/ # insmod /system/lib/modules/pwm-ctrl.ko
+</code>
 Enable PWM via sysfs.
-  echo 100000 | sudo tee /sys/devices/platform/pwm-ctrl/freq0
-  echo 1 | sudo tee /sys/devices/platform/pwm-ctrl/enable0
+<code>
-Set duty ratio (value can be 0 to 1023. Higher is brighter)
+root@odroidc2:/ # cd /sys/devices/pwm-ctrl.43/
-  echo 1023 | sudo tee /sys/devices/platform/pwm-ctrl/duty0
+root@odroidc2:/sys/devices/pwm-ctrl.43 # ls
+driver
+duty0
+enable0
+freq0
+modalias
+power
+subsystem
+uevent
+root@odroidc2:/sys/devices/pwm-ctrl.43 # cat enable0
+PWM_0 : off
+root@odroidc2:/sys/devices/pwm-ctrl.43 # echo 1 > enable0
+root@odroidc2:/sys/devices/pwm-ctrl.43 # cat enable0
+PWM_0 : on
+</code>
+Set default frequency.
+<code>
+root@odroidc2:/sys/devices/pwm-ctrl.43 # echo 100000 > freq0
+</code>
+Set duty ratio.\\
+Value can be 0 to 1023 and lower value means brighter.
+<code>
+root@odroidc2:/sys/devices/pwm-ctrl.43 # cat duty0
+
+root@odroidc2:/sys/devices/pwm-ctrl.43 #echo 160 > duty0
+root@odroidc2:/sys/devices/pwm-ctrl.43 # cat duty0
+
+</code>
 ==== 4.  How to Set Auto Backlight On/Off by Monitor Status ====