Linux Display Features

Revision as of 05:41, 12 August 2016 by Winston.huang (Talk | contribs) (Android)

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Single Channel LVDS Panel


The following operations are performed with RSB-4210 (i.MX5).
  • u-boot
specify boot logo
showlogo=mmc read 0 0x70200000 0x0 0x1; fatload mmc 0:1 0x76000000 ulogo.bmp; bmp d 0x76000000
mmc read 1 0x70200000 0x0 0x1; fatload mmc 1:1 0x76000000 ulogo.bmp; bmp d 0x76000000
specify the variable bootargs_base as below:
setenv bootargs_base 'setenv bootargs console=ttymxc0,115200 ldb=single,di=1,ch0_map=JEIDA,ch1_map=JEIDA video=mxcdi0fb:RGB24,AUO- G070VW01 di1_primary,bpp=24'


  • u-boot
specify the variable bootargs_base as below:
setenv bootargs_base 'setenv bootargs console=ttymxc0,115200 enable_wait_mode=off video=mxcfb0:dev=ldb,1024x768M@60,if=RGB24 ldb=sin0'

Dual Channel LVDS Panel

Calculating Timings parameter of LVDS Panel SOP OS: Yocto 1.8 Modify imx6qdl-advantech.dtsi Step1: In ldb parameter, add parameter --> split-mode; /* dual-channel setting *

  &ldb {
       ext_ref = "true";
       status = "okay";
       split-mode; /* dual-channel setting */

Step2: In lvds-channel@1, change [crtc = "ipu1-di1";] to [crtc = "ipu1-di0";]

       lvds-channel@1 {
               fsl,data-mapping = "spwg";
               fsl,data-width = <24>;
               /* crtc = "ipu1-di1"; */
               crtc = "ipu1-di0"; /* dual-channel setting */
               status = "okay";

Step3: In display-timings native-mode = <&timing0>, Delete the other panel parameter.Add" LTI370LN01 " Parameter

        //Dual channel panel
                       timing0: lti370ln01 {
                               clock-frequency = <148500000>;
                               hactive = <1920>;
                               vactive = <544>;
                               hback-porch = <70>;
                               hfront-porch = <70>;
                               vback-porch = <200>;
                               vfront-porch = <200>;
                               hsync-len = <140>;
                               vsync-len = <185>;

Calculating Timings parameter Check your panel Timing table Example : samsung 37 inch panel

Timing lvds.png
Timing lvds2.png

(1)clock-frequency --> Clock (MHz)

(2)hactive --> Horizontal Active Display Period

(3)vactive --> Vertical Active Display Period

(4)hback-porch + hfront-porch + hsync-len (Total) = Blanking = Horizontal Total - Horizontal Active Display Period

(5)vback-porch + vfront-porch + vsync-len (Total) = Blanking = Vertical Total - Vertical Active Display Period

Touchscreen Panel

E21D03U-C01-04 Irtouch-Dualtouch

IRTOUCH panel [Android 4.4]

 (1) Download IRTOUCH driver  (Irtouch-dualtouch-package-android-v14.2.0.0002.7z)
 (2) Download IRTOUCH SWAP mode tool (Swapmode.7z)
 (3) Swap mode
     You need to check and swap IRTOUCH 0X80.
     Please install SWAP mode tool in win7.
     Run SwapModeTool.exe and choose IRTOUCH 0X80.  
 (4) Installing the IRTOUCH Dual-touch Touchscreen Driver
     (a) irtouchusb-dt.c locate to kernel_imx/driver/input/touchscreen;
     (b) modify Makefile in kernel_imx/driver/input/touchscreen
         add:  "obj-$(CONFIG_TOUCHSCREEN_USBIRTOUCH_DT)	+= irtouchusb-dt.o"
     (c) modify Kconfig in kernel_imx/driver/input/touchscreen
                tristate "IRTOUCH USB Touchscreen Driver For single point"
                depends on USB_ARCH_HAS_HCD
                select USB
                  Say Y here if you have a IRTOUCH based touchscreen
                  If unsure, say N.
                  To compile this driver as a module, choose M here: the
                  module will be called irtouch.
     (d)  You can make menuconfig select TOUCHSCREEN_USBIRTOUCH_DT and build kernel 
          Modify defconfig CONFIG_TOUCHSCREEN_USBIRTOUCH_DT=y
          example : imx6_rsb4410_android_kk44_defconfig
     (e)  Add one line to Android file system's ueventd.rc: 
          File path : device/fsl/imx6/etc/ueventd.freescale.rc  
          /dev/irtouch      0666   root    root
     (f)  Copy "Vendor_6615_Product_0081.idc" and "Vendor_6615_Product_0080.idc" file to the Android file system's /usr/idc directory. 
 (5)  Calibration the Touchscreen
         Install CalibrationTools.apk and run "CalibrationTools" to start calibrate touchscreen. 
         class name:  CalibrationToolsActivity

eGTouch touch panel [Android 4.2 ~ Android 4.4]

 (1) Add "eGalaxCalibrator" PRODUCK PACKAGES in device/fsl/imx6/
 (2) Add eGtouch file path in device/fsl/imx6/
     device/fsl/common/input/eGTouch_v2.5.2320.A/eGalaxTouch_VirtualDevice.idc:system/usr/idc/eGalaxTouch_VirtualDevice.idc \
     device/fsl/common/input/eGTouch_v2.5.2320.A/eGTouchA.ini:data/eGTouchA.ini \
     device/fsl/common/input/eGTouch_v2.5.2320.A/eGTouchD:system/bin/eGTouchD \
 (3) Add eGtouch idc and ini file in device/fsl/imx6/BoardConfigCommon.mK
 (4) Add service about eGTouch in device/fsl/rsb_4410/init.rc
      service eGTouchD /system/bin/eGTouchD
        class main
        user root
        group root
        oneshot      [Android 4.2 and 4.4 MP version is include eGTouch function]


The following operations are performed using Linux BSP 4410LBV2080.
  • u-boot
apparently specify LDB-VGA in video item contained in the variable bootargs_base
setenv bootargs_base 'setenv bootargs console=ttymxc0,115200 enable_wait_mode=off video=mxcfb0:dev=ldb,LDB-VGA,if=RGB666'
  • linux kernel
in drivers/video/mxc/ldb.c, insert the following lines into static struct struct fb_videomode ldb_modefb[] (or modify the exist element contained "LDB-VGA") :
 "LDB-VGA", 60, 640, 480, 39722,
 50, 80,
 24, 18,
 30, 10,



The following operations are performed with RSB-4410(4410LBV2080 and

  • u-boot
specify the variable bootargs_base as below:
setenv bootargs_base 'setenv bootargs console=ttymxc0,115200 enable_wait_mode=off video_mode=extension video=mxcfb0:dev=ldb,800x480M@60,if=RGB666,bpp=32 ldb=sin0'
  • linux kernel source
  1. drivers/input/evdev.c
    IDK-1107WR-40WVA1E linux evdev.png
  2. drivers/input/mousedev.c
    IDK-1107WR-40WVA1E linux mousedev.png
  3. drivers/input/joydev.c
    IDK-1107WR-40WVA1E linux joydev.png
  • linux kernel config

Device Drivers --->
Input device support --->
<*> Event interface
Miscellaneous devices --->
<*> User level driver support
HID Devices --->
[*] /dev/hidraw raw HID device support
Special HID drivers --->
<*> HID Multitouch panels


Device Drivers --->
Input device support --->
[*] Touchscreens --->
< > USB Touchscreen Driver

  • root filesystem
IDK-1107WR-40WVA1E rootfs.png


The following operations are performed with RSB-4410(4410ABV1080 and