UART_EE_A RTS and CTS

Post Reply
rpineau
Posts: 22
Joined: Sun Sep 30, 2018 12:19 pm
languages_spoken: english
ODROIDs: XU4
Has thanked: 0
Been thanked: 1 time
Contact:

UART_EE_A RTS and CTS

Unread post by rpineau » Mon Aug 12, 2019 12:29 pm

On the expansion connection page ( https://wiki.odroid.com/odroid-n2/hardw ... connectors ) I can see that pin 29 and 31 are UART_EE_A_CTS and UART_EE_A_RTS.
I've enable the UART_EE_A but if I select hardware flow control in minicom (aka rts/cts flow control) and do the same on the other end, this doesn't work (no data as I guess RTS never goes to the right state and CTS is not read).
Is there something else that needs to be done to actually enable these pins as RTS/CTS for UART_EE_A ?

Rodolphe

User avatar
odroid
Site Admin
Posts: 31760
Joined: Fri Feb 22, 2013 11:14 pm
languages_spoken: English
ODROIDs: ODROID
Has thanked: 83 times
Been thanked: 241 times
Contact:

Re: UART_EE_A RTS and CTS

Unread post by odroid » Mon Aug 12, 2019 6:30 pm

Did you modify the DeviceTree file arch/arm64/boot/dts/amlogic/meson64_odroidn2.dts and compile it?
You have to add the following lines in the DT file to enable the hw flow-control feature.

Code: Select all

&uart_A {
   status = "okay";
};
We tested the RTS/CTS functionality with two N2 boards and it worked well.

rpineau
Posts: 22
Joined: Sun Sep 30, 2018 12:19 pm
languages_spoken: english
ODROIDs: XU4
Has thanked: 0
Been thanked: 1 time
Contact:

Re: UART_EE_A RTS and CTS

Unread post by rpineau » Mon Aug 12, 2019 11:14 pm

I did not modify the device tree.
I guess I need the kernel sources for this. I was hopping to not have to have to compile anything and be able to enable this via /sys or and other sysctl. I have no issue compiling kernel and other things but this means my project will have a non standard kernel and if our users do an update without doing the above tit will break what was done.

User avatar
tobetter
Posts: 3764
Joined: Mon Feb 25, 2013 10:55 am
languages_spoken: Korean, English
ODROIDs: X, X2, U2, U3, XU3, C1
Location: Paju, South Korea
Has thanked: 28 times
Been thanked: 128 times
Contact:

Re: UART_EE_A RTS and CTS

Unread post by tobetter » Mon Aug 12, 2019 11:48 pm

rpineau wrote:
Mon Aug 12, 2019 11:14 pm
I did not modify the device tree.
I guess I need the kernel sources for this. I was hopping to not have to have to compile anything and be able to enable this via /sys or and other sysctl. I have no issue compiling kernel and other things but this means my project will have a non standard kernel and if our users do an update without doing the above tit will break what was done.
You can add this command after fdt addr ${dtb_loadaddr} in boot.ini.

Code: Select all

fdt set /serial@ffd24000 status okay

rpineau
Posts: 22
Joined: Sun Sep 30, 2018 12:19 pm
languages_spoken: english
ODROIDs: XU4
Has thanked: 0
Been thanked: 1 time
Contact:

Re: UART_EE_A RTS and CTS

Unread post by rpineau » Tue Aug 13, 2019 1:02 am

I already have this as a one time setup :

Code: Select all

fdtput -t s /media/boot/meson64_odroidn2.dtb /serial@ffd24000 status "okay"
to enable the serial port. So is the above just another way or does it actually enable the RTS/CTS mapping of the pins ?


And the kernel boot log shows all 3 serial port being enabled :

Code: Select all

[    1.017389] ff803000.serial: clock gate not found
[    1.017414] meson_uart ff803000.serial: ==uart0 reg addr = ffffff80084f5000
[    1.017436] ff803000.serial: ttyS0 at MMIO 0xff803000 (irq = 34, base_baud = 1500000) is a meson_uart
[    1.017446] meson_uart ff803000.serial: ttyS0 use xtal(24M) 24000000 change 0 to 115200
[    3.116882] console [ttyS0] enabled
[    3.120750] meson_uart ffd24000.serial: ==uart1 reg addr = ffffff80084f7000
[    3.127641] ffd24000.serial: ttyS1 at MMIO 0xffd24000 (irq = 42, base_baud = 1500000) is a meson_uart
[    3.137141] meson_uart ffd23000.serial: ==uart2 reg addr = ffffff80084f9000
[    3.144104] ffd23000.serial: ttyS2 at MMIO 0xffd23000 (irq = 43, base_baud = 1500000) is a meson_uart
but nothing about RTS/CTS even after adding what you posted above in boot.ini
Rodolphe

Post Reply

Return to “Hardware and peripherals”

Who is online

Users browsing this forum: No registered users and 2 guests