[SOLVED] Parallel port not in /dev/ folder

giuliom_95 · 04-12-2013, 03:36 PM

I have to use my parallel port so, I've looked for it as /dev/parport0 but I haven't found it. I've checked also my kernel configuration and I've seen that the "Device Drivers" > "Parallel port support" option is built-in the kernel. If I run the command "dmesg | grep parport", I get:

Code:

[    0.600536] parport_pc 00:06: reported by Plug and Play ACPI
[    0.600659] parport0: PC-style at 0x378 (0x778), irq 7 [PCSPP(,...)]

What can I do for make it work?

druuna · 04-14-2013, 05:29 AM

Not sure if this will help but: If I look at the parport.txt file (in the ../linux.<version>/Documentation directory) I notice that the naming would be /dev/lp0, /dev/lp1, ... and not /dev/parport0 etc.

giuliom_95 · 04-14-2013, 05:42 AM

Thanks for reply, but there isn't /dev/lp0 too. I've tried to run "dmesg | grep lp" but there is nothing related to parallel ports...

druuna · 04-14-2013, 06:21 AM

You don't mention looking at the parport.txt file I mentioned. It might contain info that is useful to troubleshoot your problem.

giuliom_95 · 04-14-2013, 10:56 AM

I've read the parport.txt file and it mentions about a "lp driver" so, I've looked for it in the kernel config file, by typing, in the source folder, "cat .config | grep lp" but there wasn't a relevant match. What is that driver?
One more thing, I've seen also the parallel port files in "/proc": there is a folder called "parport0" as expected, but the only entry in "/proc/sys/dev/parport/parport0/devices/active" is "none" so, as the documentation says, it means that there are no device drivers using that port. What can I do now?

druuna · 04-14-2013, 11:07 AM

The Parallel port support -> PC-style hardware + Multi-IO cards (parallel and serial) settings are for general parallel port support. Look in Block devices -> Parallel port IDE device support for the appropriate driver(s) to install for your hardware.

I cannot test this myself (no parallel port present).

giuliom_95 · 04-14-2013, 02:37 PM

Well, reading the description of the "Parallel port IDE device support" option it seems to be something related to IDE devices that are connected to the machine trough the parallel port so nothimg that helps in my case... Are there any other suggestion?

stoat · 04-14-2013, 05:27 PM

Quote:

Originally Posted by giuliom_95

Well, reading the description of the "Parallel port IDE device support" option it seems to be something related to IDE devices that are connected to the machine trough the parallel port so nothimg that helps in my case... Are there any other suggestion?

Quote:

Originally Posted by giuliom_95

I've read the parport.txt file and it mentions about a "lp driver" so, I've looked for it in the kernel config file, by typing, in the source folder, "cat .config | grep lp" but there wasn't a relevant match. What is that driver?

Then what ARE you going to use this parallel port for? A printer, maybe? If so, then see if you have parallel printer support enabled in the kernel config. That is the lp driver you asked about.

Code:

|...Device Drivers --->
|    |
|    |...<M> Parallel port support ---> (CONFIG_PARPORT=m, module=parport)
|    |        |
|    |        |...<M> PC-style hardware (CONFIG_PARPORT_PC=m, module=parport_pc)
|    |        |
|    |
|    |...Character devices --->
|    |    |
|    |    |...<M> Parallel printer support (CONFIG_PRINTER, module=lp)

Anyway, I prefer configuring all this stuff as modules. If the lp module does not load automatically, then add a single line with lp to /etc/sysconfig/modules.

giuliom_95 · 04-15-2013, 12:07 AM

I want to use the parallel port for programming an atmega microcontroller by a DAPA dongle so, what I need for the printer‘s and IDE‘s drivers, if it not even creates a symlink in the /dev/ folder? I thought that the parallel port, for his very simple nature, doesn‘t work like the USB ports(I connect the device, udev recognizes it, a symlink in /dev is created) but it‘s something always ready to use. However I‘ll recompile the kernel with those options as soon as possible. Thanks for helping.

giuliom_95 · 04-15-2013, 02:19 PM

I missed to built the ppdev kernel module. It was the key. Thanks however for helping.