You need persistent device naming rules in udev. The udev rules will basically match cretain device attributes you specify in the rules file and then create device nodes/symlinks for it. So, first you need to find what those _unique_ attributes are for your device, and then write it as a udev rule. See this link for an example on how to do it for usb devices: http://hintshop.ludvig.co.nz/show/persistent-names-usb-serial-devices/ Thats just one example. I'm sure there are many howtos out there which explain how to write udev rules. HTH, -mandeep On Wed, Mar 5, 2014 at 12:18 PM, Srinivas Ganji <srinivasganji.kernel@xxxxxxxxx> wrote: > Dear All, > > We have a USB CDC device which we are connecting it to the Ubuntu system. > Then, we are accessing the device using an application by opening the device > with /dev/ttyACM0 node. The system may have multiple USB CDC devices already > connected before connecting my device, sometimes. In such cases, my > application fails to open the device, because, this time the assigned node > is other than /dev/ttyAMC0, but in my application the device node is > /dev/ttyAMC0 only. Due to these reasons, I want to assign my own device node > in the /dev directory like /dev/mydev. This will enable my application to > identify my device very easily. > > The requirement is same as described in the link - > http://marc.info/?l=linux-usb&m=130216901901572&w=2 > The answer is available at > http://marc.info/?l=linux-usb&m=130217684009490&w=2 > > I have tried in different ways as I have also looked at the following > sources. But, still, there is NO luck. When I insert another USB CDC device, > it got /dev/ttyACM0 instead of getting ttyACM1. > http://www.reactivated.net/writing_udev_rules.html > https://www.kernel.org/pub/linux/utils/kernel/hotplug/udev/udev.html > http://unix.stackexchange.com/questions/77476/point-usb-phone-to-specific-dev-ttyacm-using-udev > https://www.pjrc.com/teensy/49-teensy.rules > > The kernel version and distribution details are as follows. > Kernel Version --- 3.5.0-17-generic > Distribution details are as follows. > RELEASE=14 > CODENAME=nadia > EDITION="MATE 64-bit" > DESCRIPTION="Linux Mint 14 Nadia" > > I have created a file, named 11-ttyACM.rules, under /etc/udev/rules.d > directory. The contents of the file as follows. > KERNEL=="ttyAMC0", SUBSYSTEM=="tty", ATTRS{serial}=="__0X00124B000148CC78", > SYMLINK+="mydev" > > I got the above information from the following command > udevadm info -q all -n /dev/ttyACM0 --attribute-walk > > This is what I did. But, no luck. If I insert a different serial numbered > device, then it is assigning ttyACM0 to that device. But, after this udev > rule, it should not assign, I think. > > Please someone, who already used/knows udev rules, suggest me. > > Thanks. > > Regards, > Srinivas. > > _______________________________________________ > Kernelnewbies mailing list > Kernelnewbies@xxxxxxxxxxxxxxxxx > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
