usbserial on ARM

I have an ARM based board with usb interface. To use the usb interface I use the following commands:

insmod usbserial.ko vendor=0x... product=0x... > mknod /dev/ttyUSB0 c 188 0

If I try to use the device with echo or cat I get the error "No such device". Could you help me?

Bye

Reply to
ghiggia
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vendor=0x... product=0x...

"modprobe", which should load all dependencies as well. Eg: usbserial probably needs the USB core, USB Hub, OHCI/EHCI .... modules etc. Also check the log files (dmesg, syslog etc) to see if those modules were successfully loaded. Cheers Janaka

Reply to
Janaka

vendor=0x... product=0x...

With modinfo I see that the module usbserial doesn't have dependency. In this case insmod and modprobe do the same work?

modinfo drivers/usb/serial/usbserial.ko filename: drivers/usb/serial/usbserial.ko author: Greg Kroah-Hartman, snipped-for-privacy@kroah.com,

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description: USB Serial Driver core license: GPL vermagic: 2.6.18-rc2-rev.1.0.2.1 mod_unload ARMv5 gcc-3.3 depends: parm: product:User specified USB idProduct (ushort) parm: vendor:User specified USB idVendor (ushort) parm: debug:Debug enabled or not (bool)

Bye

Reply to
ghiggia

usbserial.ko vendor=0x... product=0x...

That doesn't sound right! You may have the core Usb modules ..etc compiled in to the kernel or a strange setup. The reason I say the above is, USB is a reasonably complex bus with multiple levels of control. At the highest level there must be a root hub. Some boards have a dedicated chip for this, and some others have it on their processor (an SOC design). To enable and operate that you need a kernel driver/module. Next level down you may (or may not) have a USB hub, which increases the number of USB devices that can be connected to the Root hub and takes care of power needs. This may have further control/driver modules. Next level down in the tree structure will be your device driver for the USB serial product (Most likely a CDC [communications device] or a HID [ Human interface Device]). There may be more layers depending on the complexity of the HW setup.

The other thing could be that modinfo may not show all the dependencies if a SOC controlling code is in a one big driver. If none of the above helps, you can try dividing the problem and to solve it:

  1. Is the USB port working for other types of devices
  2. Is the USB to serial setup working Good luck!
Reply to
Janaka

vendor=0x... product=0x...

You do not have the device driver at all. usbserial is a module for the common parts of USB serial drivers.

As an example, I plugged in a simple USB serial cable, Aten International Co Ltd UC-232A, vendor ID 0x557 and product ID 0x2008.

It needs the modules:

pl2303 usbserial, used by pl2303

The command

modprobe pl2303

loads both modules.

HTH

--

Tauno Voipio
tauno voipio (at) iki fi
Reply to
Tauno Voipio

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