how to enable element14 7 touchscreen+LCD on nougat for PI2/3?

[wad...@gmail.com]

Hello,

  I can enable element14 7 touchscreen on nougat for PI3 by 

1. modify config.txt
  dtoverlay=vc4-kms-v3d,cma-256,rpi-ft5406

  ==> put rpi-ft5406.dtbo into BOOT/overlay/rpi-ft5406.dtbo

  ==> I also put rpi-ft5406-overlay.dts into BOOT/overlay/rpi-ft5406-overlay.dts too.

2. modify cmdline.txt

  console=tty1

  ==> remove original console=serial0,115200....

  But I don't know how to set the main display to the 7" monitor.

Could anyone show me how to modify source code? 

Thanks.

[chen wade]

I found that I could found there are two framebuffer device on /dev/graphic/fb[01] by:

1. Turn on the CONFIG_FB_TFT and CONFIG_FB_TFT_ILI9341=y ....and

2. modified dtoverlay=rpi-display,vc4-kms-v3d,rpi-ft5406 on config.txt

But...the system will be failed on surfaceflinger... :(

chen wade於 2016年12月1日星期四 UTC+8下午5時20分43秒寫道：

[neilcu...@googlemail.com]

Don't include rpi-display as this is for the "RPi-Display - 2.8" Touch Display by Watterott"

rpi-ft5406 does make the touchscreen work but until the screen position is fixed you have to press an inch to the left of where you want to hit.

I have included the following overlay but that doesn't effect the brightness levels or position:
Name:   rpi-backlight
Info:   Raspberry Pi official display backlight driver
Load:   dtoverlay=rpi-backlight
Params: <None>

[neilcu...@googlemail.com]

Pinpointed the issue to the vc4-kms-v3d overlay. Read the same experience happened when they tried to load Ubuntu but appeared to be fix by changing the gpu_memory amount, however this didn't work for me.

So I swapped that overlay for the vc4-fkms-v3d overlay and the screen centered properly and actually showed my the "A N D R O I D _" visual which i didn't get before (was just black). However, as soon as it came to the main boot loader visual, it froze.

[chen wade]

My hardware components are:

1. RPI3

2. 7" touch screen from element14

3. 22" HDMI LCD panel from ViewSonic

My config.txt to work with HDMI output and 10-points touch function gracefully as:

dtoverlay=vc4-kms-v3d,cma-256,rpi-ft5406

kernel=zImage

initramfs ramdisk.img 0x01f00000

display_default_lcd=1

hdmi_force_hotplug=1

hdmi_drive=2

hdmi_group=1

hdmi_mode=4

config_hdmi_boost=4

framebuffer_width=1280 

framebuffer_height=720

hdmi_force_hotplug=1

device_tree=bcm2710-rpi-3-b.dtb

dtparam=audio=on

hdmi_cvt=1280 720 60 6 0 0 0

mask_gpu_interrupt0=0x400 

avoid_warnings=2

gpu_mem=256

enable_uart=1

disable_overscan=1

disable_splash=0

My cmdline.txt to work with 7" for the console output gracefully:
initrd=0x01f00000 dwc_otg.lpm_enable=0 console=tty1 no_console_suspend root=/dev/ram0 acpi_irq_nobalance noirqbalance isolcpus=1 elevator=deadline rootwait androidboot.hardware=rpi3 androidboot.selinux=permissive

But what I want is to turn on the second framebuffer for dual display application.