Waveshare-DSI-LCD can not display for yocto image with linux-raspberrypi 6.1.34 & 6.1.38

[gitgonewithwind]

Hi
I post my issue here:

https://github.com/waveshare/Waveshare-DSI-LCD/issues/4#issuecomment-1662683896
in that page shows if the kernel > 6.1.25 , it can support Waveshare-DSI-LCD,

I used meta-raspberrypi with yocto
commit dff85b9
linux-raspberrypi-6.1: Update to 6.1.34 release

but it seems the kernel can not communicate with i2c,
so do I need to modify the default dtb(dts )file to enable i2c?
how can I do ? I want to know if the issue is about i2c communicate or something else?

Thank you very much.

[gitgonewithwind]

hi all ,
do you have any idea?
I have updated kernel to 6.1.38 and built the drivers in kernel, but it still can not work for waveshare-dsi-lcd in yocto image. I do no know how to do now
and I tried to set "okay" in dsi1 in dtsi ,but it not useful.
I want to know if ycoto image not support it ? but I think if the kernel support it in raspbian image? In my option ,it should support it.
I do not know why not work
any idea ? @agherzan
Thanks

root@raspberrypi4-64:# ls /dev/i2c*
/dev/i2c-0 /dev/i2c-1 /dev/i2c-10 /dev/i2c-20 /dev/i2c-21 /dev/i2c-22
root@raspberrypi4-64:# modinfo panel-waveshare-dsi
name: panel_waveshare_dsi
filename: (builtin)
license: GPL
file: drivers/gpu/drm/panel/panel-waveshare-dsi
description: Waveshare DSI panel driver
author: Dave Stevenson dave.stevenson@raspberrypi.com
root@raspberrypi4-64:# modinfo goodix_ts
name: goodix_ts
filename: (builtin)
license: GPL v2
file: drivers/input/touchscreen/goodix_ts
description: Goodix touchscreen driver
author: Bastien Nocera hadess@hadess.net
author: Benjamin Tissoires benjamin.tissoires@gmail.com
root@raspberrypi4-64:# uname -a
Linux raspberrypi4-64 6.1.38-v8 #1 SMP PREEMPT Mon Jul 10 18:26:47 UTC 2023 aarx
root@raspberrypi4-64:~# ls /dev/i2c*
/dev/i2c-0 /dev/i2c-1 /dev/i2c-10 /dev/i2c-20 /dev/i2c-21 /dev/i2c-22

config.txt

dtparam=i2c1=on
dtparam=i2c_arm=on
enable_uart=1
dtoverlay=vc4-kms-v3d
dtparam=i2c_arm=on
dtoverlay=vc4-kms-v3d
dtoverlay=vc4-kms-dsi-waveshare-panel,8_0_inch
dtparam=i2c_vc=on

[agherzan]

I am not sure how to guide you from here. I think the right way would be to ask, as you already did, on waveshare.

[omarhogni]

Here are the steps I used to get this working for me.

You do need to update the kernel version provided in meta-raspberrypi to a version that includes
the driver raspberrypi/linux#5433.

I created a file called linux-raspberrypi_6.1.bbappend

LINUX_VERSION = "6.1.46"
SRCREV_machine = "e89e7655a197d28df49da2be7e2003436cf52197"

Then you need to add the driver dtbo file into /boot of the device for that you need to add

RPI_KERNEL_DEVICETREE_OVERLAYS += "\
  <... REPLACE THIS WITH ALL THE OVERLAYS YOU NEED ...>
  overlays/vc4-kms-dsi-waveshare-panel.dtbo \
"

For rest that you need I just used the default as a template and worked
from there. If you add this line to your local conf the built in one
does not apply anymore so beware.

You also need to enable i2c and configure the driver for you panel

KERNEL_MODULE_AUTOLOAD:rpi += " i2c-dev"

RPI_EXTRA_CONFIG = '\n \
# ----- CUSTOM OPTIONS SET IN local.conf ----------\n \
# Raspberry Pi 10_1 dsi \" display/touch screen \n \
dtparam=i2c_arm=on \n \
dtoverlay=vc4-kms-dsi-waveshare-panel,10_1_inch \n \
# ----- END CUSTOM OPTIONS SET IN local.conf ------ \n \
'

This was sufficient to get my 10" display working.
Hope this helps!

[gitgonewithwind]

HI @omarhogni
thank you so much.

I did not do this step before :

RPI_KERNEL_DEVICETREE_OVERLAYS += "
<... REPLACE THIS WITH ALL THE OVERLAYS YOU NEED ...>
overlays/vc4-kms-dsi-waveshare-panel.dtbo
"
in my understanding , I am going to add this line "overlays/vc4-kms-dsi-waveshare-panel.dtbo" to file conf/machine/include/rpi-base.inc , can not add this line in build/conf/local.conf , right?
let me try

[gitgonewithwind]

@omarhogni
your solution works well 8" display
Thank you so much.
close the issue. please. @agherzan thank you so much

[bhaggenmiller]

Here are the steps I used to get this working for me.

You do need to update the kernel version provided in meta-raspberrypi to a version that includes the driver raspberrypi/linux#5433.

I created a file called linux-raspberrypi_6.1.bbappend

LINUX_VERSION = "6.1.46"
SRCREV_machine = "e89e7655a197d28df49da2be7e2003436cf52197"

Then you need to add the driver dtbo file into /boot of the device for that you need to add

RPI_KERNEL_DEVICETREE_OVERLAYS += "\
  <... REPLACE THIS WITH ALL THE OVERLAYS YOU NEED ...>
  overlays/vc4-kms-dsi-waveshare-panel.dtbo \
"

For rest that you need I just used the default as a template and worked from there. If you add this line to your local conf the built in one does not apply anymore so beware.

You also need to enable i2c and configure the driver for you panel

KERNEL_MODULE_AUTOLOAD:rpi += " i2c-dev"

RPI_EXTRA_CONFIG = '\n \
# ----- CUSTOM OPTIONS SET IN local.conf ----------\n \
# Raspberry Pi 10_1 dsi \" display/touch screen \n \
dtparam=i2c_arm=on \n \
dtoverlay=vc4-kms-dsi-waveshare-panel,10_1_inch \n \
# ----- END CUSTOM OPTIONS SET IN local.conf ------ \n \
'

This was sufficient to get my 10" display working. Hope this helps!
Hey I am new to Yocto and the DTS stuff. Could you help me with explaining this in a little bit more detail. Especially where to edit what. Thanks

[gitgonewithwind]

@bhaggenmiller

1. at you build folder conf/local.conf to add the following:

RPI_EXTRA_CONFIG = '\n \

----- CUSTOM OPTIONS SET IN local.conf ----------\n \

Raspberry Pi 10_1 dsi " display/touch screen \n \

dtparam=i2c_arm=on \n
dtoverlay=vc4-kms-dsi-waveshare-panel,8_0_inch \n \

----- END CUSTOM OPTIONS SET IN local.conf ------ \n \

'

2. depend on what git commit your are using meta-raspberrypi because the solution is months ago

I am using Author: Vivien Didelot vivien.didelot@gmail.com
Date: Thu Aug 3 01:36:48 2023 -0400

anyway similarly
at folder meta-raspberrypi/recipes-kernel/linux there was a latest linux version (at a few month ago) .bb file linux-raspberrypi_6.1.bb
so you
I created a file called linux-raspberrypi_6.1.bbappend

LINUX_VERSION = "6.1.46"
SRCREV_machine = "e89e7655a197d28df49da2be7e2003436cf52197"

when building, it will download the commit of source code. (maybe the currently master of meta-raspberrypi updated version already support DSI LCD, so you do not need this step

3, in file meta-raspberrypi/conf/machine/include/rpi-base.inc to add overlays/vc4-kms-dsi-waveshare-panel.dtbo
"
RPI_KERNEL_DEVICETREE_OVERLAYS += "
<... REPLACE THIS WITH ALL THE OVERLAYS YOU NEED ...>
overlays/vc4-kms-dsi-waveshare-panel.dtbo
"

and then, It will be :

overlays/vc4-kms-v3d-pi4.dtbo
overlays/vc4-kms-dsi-7inch.dtbo
overlays/w1-gpio.dtbo
overlays/w1-gpio-pullup.dtbo
overlays/wm8960-soundcard.dtbo
overlays/vc4-kms-dsi-waveshare-panel.dtbo
"

(same, maybe updated master of meta-raspberrypi version already added it, please have a look)

hope it can help you

if master of meta-raspberrypi version is already added it (I forget from what kernel version , it already support DSI), so you do not need step 2 to download "6.1.46" and commit "e89e7655a197d28df49da2be7e2003436cf52197".

you only need step 1 and step 3 ,I think

[talksik]

I have tried to create a custom yocto image on top of boot2qt. I am running into the following problems:

1. blank screen.
2. Qt app won't run as it says "No screens found" or "No DRM device found".

I tried to troubleshoot, but I am out of ideas.

Context:

• I have a yocto custom boot2qt image that enables i2c via meta-raspberrypi settings.
• My config has dtoverlay=vc4-kms-dsi-waveshare-panel,2_8_inch as waveshare's guide says.
• I've tried every different variant of vc4-fkms-v3d and vc4-kms-v3d and vc4-kms-v3d-pi4

Output of lsmod | grep waveshare

root@b2qt-raspberrypi4-64:~# lsmod | grep waveshare
panel_waveshare_dsi    16384  0
backlight              24576  1 panel_waveshare_dsi

Output of ls /dev/dri

root@b2qt-raspberrypi4-64:~# ls /dev/dri/
by-path     card0       card1       renderD128

My entire config.txt file:

# Enable SPI bus
dtparam=spi=on
# Enable I2C
dtparam=i2c1=on
dtparam=i2c_arm=on

# Enable VC4 Graphics
# dtoverlay=vc4-kms-v3d # was causing problems with DSI display
# https://bugreports.qt.io/browse/QTBUG-106112
# https://forum.qt.io/topic/152160/official-7-raspberry-touch-screen-lcd-isn-t-working-with-boot2qt-6-6-for-raspberry-pi-4-64-bit/2
dtoverlay=vc4-fkms-v3d
# dtoverlay=vc4-kms-v3d-pi4

# Enable USB peripheral mode
dtoverlay=dwc2,dr_mode=peripheral
# Enable the onboard ALSA audio
dtparam=audio=on
dtoverlay=vc4-kms-dsi-waveshare-panel,2_8_inch

# enable both hdmi outputs
# max_framebuffers=2 # disabled to prevent conflict with DSI display

Linux kernel version:

root@b2qt-raspberrypi4-64:~# uname -a
Linux b2qt-raspberrypi4-64 6.1.54-v8 #1 SMP PREEMPT Wed Sep 20 14:13:53 UTC 2023 aarch64 GNU/Linux

Confirmed that I have waveshare overlay:

root@b2qt-raspberrypi4-64:~# ls /boot/overlays/ | grep waveshare
vc4-kms-dsi-waveshare-panel.dtbo
waveshare-can-fd-hat-mode-a.dtbo
waveshare-can-fd-hat-mode-b.dtbo

Note: I also tried using a compiled dtbo file from a linux kernel 6.6 /boot/overlays into my yocto image with a kernel of 6.1.54. This workaround doesn't load the module when querying: lsmod | grep waveshare.

Here is the dmesg error that repeats endlessly:

...
[  469.247935] Goodix-TS 10-0014: Error writing 1 bytes to 0x814e: -110
[  470.271888] i2c-bcm2835 fe205000.i2c: i2c transfer timed out
[  470.271936] Goodix-TS 10-0014: Error reading 10 bytes from 0x814e: -110
[  471.295900] i2c-bcm2835 fe205000.i2c: i2c transfer timed out
[  471.295949] Goodix-TS 10-0014: Error writing 1 bytes to 0x814e: -110
[  472.319893] i2c-bcm2835 fe205000.i2c: i2c transfer timed out
[  472.319944] Goodix-TS 10-0014: Error reading 10 bytes from 0x814e: -110
...

Problem: my screen is blank. My Qt app says "No screens available" or "No DRM device" depending on which vc4-* overlay I load.

Ahh, I'm out of ideas and lost. If anyone can give me any sort of hints that helped them, I'd appreciate it!

Could this be a faulty device that needs to be replaced? The display works with a latest version of raspbian.

[talksik]

Long couple days, but fixed.

1. Made sure to use 6.1.46 as noted in this thread. Don't know if this is absolutely necessary.
2. Another layer meta-boot2qt that I was building with enabled raspberry pi camera. From my research, I found other people had this problem of the DSI, GPIO, and camera i2c causing conflicts.
3. I made sure to adjust the KERNEL_MODULE_AUTOLOAD as noted in this thread as the meta-raspberrypi docs state a different method that is likely targeted for latest branches.

Thank you for the hints! I wonder if these problems never would have occurred if I updated the kernel to 6.6.x. I avoided this as I am a newbie when it comes to yocto and upgrading all layers seems daunting to me. Regardless, learned a lot of pieces from this debacle 😆

[bhaggenmiller]

@bhaggenmiller

1. at you build folder conf/local.conf  to add the following:

RPI_EXTRA_CONFIG = '\n \

----- CUSTOM OPTIONS SET IN local.conf ----------\n \

Raspberry Pi 10_1 dsi " display/touch screen \n \

dtparam=i2c_arm=on \n dtoverlay=vc4-kms-dsi-waveshare-panel,8_0_inch \n \

----- END CUSTOM OPTIONS SET IN local.conf ------ \n \

'

2. depend on  what git commit your are using meta-raspberrypi  because the solution is months ago

I am using Author: Vivien Didelot vivien.didelot@gmail.com Date: Thu Aug 3 01:36:48 2023 -0400

anyway similarly at folder meta-raspberrypi/recipes-kernel/linux there was a latest linux version (at a few month ago) .bb file linux-raspberrypi_6.1.bb so you I created a file called linux-raspberrypi_6.1.bbappend

LINUX_VERSION = "6.1.46" SRCREV_machine = "e89e7655a197d28df49da2be7e2003436cf52197"

when building, it will download the commit of source code. (maybe the currently master of meta-raspberrypi updated version already support DSI LCD, so you do not need this step

3, in file meta-raspberrypi/conf/machine/include/rpi-base.inc to add overlays/vc4-kms-dsi-waveshare-panel.dtbo " RPI_KERNEL_DEVICETREE_OVERLAYS += " <... REPLACE THIS WITH ALL THE OVERLAYS YOU NEED ...> overlays/vc4-kms-dsi-waveshare-panel.dtbo "

and then, It will be :

overlays/vc4-kms-v3d-pi4.dtbo overlays/vc4-kms-dsi-7inch.dtbo overlays/w1-gpio.dtbo overlays/w1-gpio-pullup.dtbo overlays/wm8960-soundcard.dtbo overlays/vc4-kms-dsi-waveshare-panel.dtbo "

(same, maybe updated master of meta-raspberrypi version already added it, please have a look)

hope it can help you

if master of meta-raspberrypi version is already added it (I forget from what kernel version , it already support DSI), so you do not need step 2 to download "6.1.46" and commit "e89e7655a197d28df49da2be7e2003436cf52197".

you only need step 1 and step 3 ,I think

Thanks for your help. The display is no working. Unfortunately the application is not working properly. It s a html5/js page which runs on localhost in cog webengine. It has some problems with the framebuffer:

swiotlb_tbl_map_single: 376 callbacks suppressed
vc4-drm gpu: swiotlb buffer is full (sz: 1441792 bytes), total 32768 (slots), used 466 (slots)

[gitgonewithwind]

@bhaggenmiller
Maybe your issue is not at DSI display, just at your APPs. I used chromium to display page. you can use a regular hdmi screen to make sure you app can run well, and then switch to DSI screen. just guess

[bhaggenmiller]

@bhaggenmiller Maybe your issue is not at DSI display, just at your APPs. I used chromium to display page. you can use a regular hdmi screen to make sure you app can run well, and then switch to DSI screen. just guess

Mhm on PI OS it works fine. Therefore i don t think the app is the problem.