uart #5 in linux

Ran,

Ran S. said:

I would like to ask where should I expect to see it. is uart number #X should be expected to be named /dev/ttySX ?

I currently see only: /dev/ttyS0, /dev/ttyS1, /dev/ttyS2, /dev/ttyS3

On the latest kernel versions, the ttySx is changed to ttyOx. Thus the serial port associated with UART5 is now referred as ttyO5. The character 'O' in the serial port name stands for "OMAP UART Port".

http://processors.wiki.ti.com/index.php/TI81XX_PSP_User_Guide#TI814X.2C_TI813X

Regards,
Pavel

Hi Pavel,

but why there is no tty05 in /dev/ ?

Regards,

Ran

Ran,

Ran S. said:

but why there is no tty05 in /dev/ ?

In which /dev? In the host machine (desktop PC) /dev or in target machine (DM814x based board) /dev?

Regards,
Pavel

Hi Pavel,

I need to use uart #5 in the target machine (DM8148). 

Currently it is not exported in /dev Linux (I see in /dev only  ttyS0 , ttyS1, ttyS2, ttyS3).

Thanks,

Ran

Ran,

In DM814x EVM & EZSDK, UART0 is used for console (ttyO0) and it is exported to /dev

This is what I have in the linux kernel boot up log:

Kernel command line: console=ttyO0,115200n8 rootwait root=/dev/mmcblk0p2 rw mem=364M@0x80000000 mem=320M@0x9FC00000 vmalloc=500M notifyk.vpssm3_sva=0xBF900000 ip=off noinitrd

omap_uart.0: ttyO0 at MMIO 0x48020000 (irq = 72) is a OMAP UART0
console [ttyO0] enabled
omap_uart.1: ttyO1 at MMIO 0x48022000 (irq = 73) is a OMAP UART1
omap_uart.2: ttyO2 at MMIO 0x48024000 (irq = 74) is a OMAP UART2
omap_uart.3: ttyO3 at MMIO 0x481a6000 (irq = 44) is a OMAP UART3
omap_uart.4: ttyO4 at MMIO 0x481a8000 (irq = 45) is a OMAP UART4
omap_uart.5: ttyO5 at MMIO 0x481aa000 (irq = 46) is a OMAP UART5

Arago Project http://arago-project.org dm814x-evm ttyO0

Arago 2011.09 dm814x-evm ttyO0

Then this is what I have in the DM814x /dev folder:

/dev/ttyO0
/dev/ttyO1
/dev/ttyO2
/dev/ttyO3
/dev/ttyO4
/dev/ttyO5
/dev/ttyS0
/dev/ttyS1
/dev/ttyS2
/dev/ttyS3

Could you please provide me full boot up log of your linux kernel? Are you aligned with the below wiki page?

http://processors.wiki.ti.com/index.php/TI81xx_PSP_Porting_Guide#Using_different_UART_than_the_default_EVM_configuration_as_console

Regards,
Pavel

You are right, I had some confusion here.

I actually have the same device as yours, I was mistakenly referring to ttySX (which end at ttyS3) instead of tty0X (which end in tty05).

Regards,

Ran

By the way, what the ttySX refers to ?

Thanks,

Ran

Hello,

I am facing some strange results with UART #5.

I configure the UART as following (19200, 8 chars, even parity, 1 stop bit, no echo, no flow control):

stty -F /dev/ttyO5 19200 cs8 parenb -parodd -cstopb

when doing echo "U" > /dev/tty05 

I see the "U", but I also see more than one transmission on scope, I don't understand yet what it represent.

The other strange thing is that the internal UART register are not changed with the above configuraion and register LCR is always 0 (also before using the stty):

echo "r 0x481aa004 1" > /sys/kernel/debug/prot_reg/mem

----------- H E X V I E W -----------
Address Data
------------------------------------------
481a:a00c : 00000000
----------------------------------------

I meanwhile ignore the above issues,  hopefully, the protocol will function correct on UART #5.

Thanks,

Ran

Hi,

for anyone with similar issue, better notice that the pinmux are modified in RDK as part of the load.sh script.

loas.sh script change pinmux for vin0 for 24 bits.

Changing the pinmux using the script solved this issue for us.

Thanks,

Ran