How uart1/2 work with out overlay dtb file

#1

Hi,
We trying to building debian (https://wiki.radxa.com/RockpiS/dev/Debian).
Kernel dts overlay does not contain uart1 and uart2 dts file.
Where uart1 and uart2 dts files is present ?
How uart1/2 work with out overlay dtb file ?
We want to use two uart at same time but uart1 rts/cts mux with uart2 we need to remove uart1 rts/cts pin from dts file.

Thanks & Regards
Vasu

#2

Any update on this? Please update soon.

#4

How about using UART0 and UART2 at the same time? If this meets your need, you can try.

You need to do the following steps.

Use system image, rockpis_debian_buster_minimal_arm64_191219_0406-gpt.img

enable UART0 and UART2 in file, /boot/hw_intfc.conf

intfc:uart0=on
intfc:uart1=off
intfc:uart2=on

And comment this line in file, /boot/hw_intfc.conf

#intfc:dtoverlay=console-on-ttyS0

Delete the following strings of command line in file, cat /boot/extlinux/extlinux.conf

earlyprintk console=ttyFIQ0,1500000n8

And the final content is this.

root@rockpis:/# cat /boot/extlinux/extlinux.conf 
timeout 10
menu title select kernel

label kernel-4.4.143-34-rockchip-g3c9d2019dba7
    kernel /vmlinuz-4.4.143-34-rockchip-g3c9d2019dba7
    initrd /initrd.img-4.4.143-34-rockchip-g3c9d2019dba7
    devicetreedir /dtbs/4.4.143-34-rockchip-g3c9d2019dba7
    append  rw init=/sbin/init rootfstype=ext4 rootwait  root=UUID=ced8410b-05fb-4347-b0ae-ad2065c7d629

Reboot. and Use adb to access ROCK Pi S.

#5

Hi @Stephen ,
We followed the steps mentioned by you.
But while using uart 0, receiving junk data and while sending also same issue.
Not able to get proper data.

#6

Hi, Here is my test.

On ROCK Pi S, use adb

 stty -F /dev/ttyS0 raw speed 115200
 cat /dev/ttyS0

On Ubuntu Host, create rockpis-uart-send.py and test.txt

$ cat rockpis-uart-send.py 
#!/bin/bash/python
# -*- coding: UTF-8 -*-
import serial
ser = serial.Serial("/dev/ttyUSB0")
ser.baudrate = 115200
ser.write(open("./test.txt","rb").read())

$ python rockpis-uart-send.py

You would see the content of test.txt on ROCK Pi S.

Would you mind doing the testing?

Usage of UART0 for application purpose
#7

Hi @Stephen
I executed same commands as mentioned.
But still getting junk data as follows.

cat /dev/ttyS0
�i�i�a� �o�a�s�i�a�i�r�d�y�
�i�i�a� �o�a�s�i�a�i�r�d�y�

#8

Here is my result.

root@rockpis:/test# uptime
 11:24:50 up  1:55,  0 users,  load average: 0.00, 0.00, 0.00
root@rockpis:/test# stty -F /dev/ttyS0 raw speed 115200
115200
root@rockpis:/test# cat /dev/ttyS0 
ROCK Pi S is a Rockchip RK3308 based SBC(Single Board Computer) by Radxa. It equips a 64bits quad core processor, USB, ethernet, wireless connectivity and voice detection engine at the size of 1.7 inch, make it perfect for IoT and voice applications. ROCK Pi S comes in two ram sizes 256MB or 512MB DDR3, and uses uSD card for OS and storage. Optionally, ROCK Pi S can provide on board storage version with 1Gb/2Gb/4Gb/8Gb NAND flash.

Make sure the Baudrate is right and do not use minicom or other serial tools for rockpis ttyS0.