UNIX for Dummies Questions & Answers

Hi,

I'm trying to develop an application to work with serial infra-red module, but I'm having difficulties to even get my module started. My HW is Beagleboard, which has 1 UART serial port, normally used for console, which I have disabled (I re-created the boot.scr, without the console arguments), and I have modified the getty config, not to try to attach to ttyO2.
On 3.x omap kernels, the serial port is now called ttyOx instead of ttySx, though I guess that doesn't really matter ? I guess the port and irq are the most important things..

During boot, I can see following information regarding the configuration:

Code:

[    0.000000] Kernel command line: console=tty0 root=/dev/mmcblk0p2 rootwait ro vram=12MB omapfb.mode=dvi:1280x720MR-16@60 fixrtc buddy=none mpurate=auto
[    0.000000] console [tty0] enabled
[    0.768524] omap_uart.0: ttyO0 at MMIO 0x4806a000 (irq = 72) is a OMAP UART0
[    0.768768] omap_uart.1: ttyO1 at MMIO 0x4806c000 (irq = 73) is a OMAP UART1
[    0.769012] omap_uart.2: ttyO2 at MMIO 0x49020000 (irq = 74) is a OMAP UART2
[    0.769226] omap_uart.3: ttyO3 at MMIO 0x49042000 (irq = 80) is a OMAP UART3

When system tries to load the lirc module (for infra-red) I get this
complain about IRQ being busy:

Code:

[   12.396392] lirc_serial: IRQ 74 busy

Now, I'm not sure now why that is still happening, as I think nobody should be connected to ttyO2 anymore. But anyway, around internet people say I should release the UART manually, and I try it with setserial, with strange reply:

Code:

ubuntu@omap:/etc$ sudo setserial /dev/ttyO2 uart none
Cannot set serial info: Invalid argument

If I try without sudo, I get "Permission denied"

Also strangely, when I try to look at the port status:

Code:

ubuntu@omap:/etc$ sudo setserial -g /dev/ttyO[0-3]
/dev/ttyO0, UART: undefined, Port: 0x0000, IRQ: 72
/dev/ttyO1, UART: undefined, Port: 0x0000, IRQ: 73
/dev/ttyO2, UART: undefined, Port: 0x0000, IRQ: 74
/dev/ttyO3, UART: undefined, Port: 0x0000, IRQ: 80

Shoudn't there be something in those port addresses ?
Does it matter that "MMIO" is used ? Normally IO port seems to be indeed 0x**** format, now the address for serial port is much higher (0x********)

Any ideas how I should proceed ?