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Vieri
l33t
Joined: 18 Dec 2005
Posts: 907
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 Posted: Mon Aug 31, 2009 7:45 am Post subject: [SOLVED] custom udev rules for usb devices |
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Hello,
I'd like to know how to write a custom udev rule so that a particular USB device is always assigned to a "custom-labeled" port, such as "RS-232-adapter-1" instead of a "variable" ttyUSB? (where ? usually changes).
I understand that the concept is to create a "RS-232-adapter-1" symlink in /dev through a custom udev rule. What's the correct way of doing this?
My USB device:
| Code: |
# lsusb -D /proc/bus/usb/002/007
Device: ID 0403:6001 Future Technology Devices International, Ltd 8-bit FIFO
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.10
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 8
idVendor 0x0403 Future Technology Devices International, Ltd
idProduct 0x6001 8-bit FIFO
bcdDevice 4.00
iManufacturer 1 FTDI
iProduct 2 usb serial converter
iSerial 3 FTCTWS1T
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 32
bNumInterfaces 1
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xa0
(Bus Powered)
Remote Wakeup
MaxPower 44mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 255 Vendor Specific Subclass
bInterfaceProtocol 255 Vendor Specific Protocol
iInterface 2 usb serial converter
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Device Status: 0x0000
(Bus Powered)
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Last edited by Vieri on Mon Aug 31, 2009 10:51 am; edited 1 time in total |
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DawgG
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Joined: 17 Sep 2003
Posts: 874
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| Posted: Mon Aug 31, 2009 9:04 am Post subject: |
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you have to find out the one distinguishing property of your device (like manufacturer, serial, etc) and put it inside the udev-rule that creates the named symlink, then the device will always get that name.
you probably have to do some reading (it's worth it :wink: ) if you haven't already:
http://reactivated.net/writing_udev_rules.html#udevinfo
GOOD LUCK!
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DUMM KLICKT GUT. |
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Vieri
l33t
Joined: 18 Dec 2005
Posts: 907
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| Posted: Mon Aug 31, 2009 9:40 am Post subject: |
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Thanks.
I did the following:
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# udevinfo -a -p /sys/class/usb_device/usbdev2.7
looking at device '/class/usb_device/usbdev2.7':
KERNEL=="usbdev2.7"
SUBSYSTEM=="usb_device"
DRIVER==""
looking at parent device '/devices/pci0000:00/0000:00:1d.0/usb2/2-2':
KERNELS=="2-2"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{serial}=="FTCTWS1T"
ATTRS{product}=="usb serial converter"
ATTRS{manufacturer}=="FTDI"
ATTRS{quirks}=="0x0"
ATTRS{maxchild}=="0"
ATTRS{version}==" 1.10"
ATTRS{devnum}=="7"
ATTRS{busnum}=="2"
ATTRS{speed}=="12"
ATTRS{bMaxPacketSize0}=="8"
ATTRS{bNumConfigurations}=="1"
ATTRS{bDeviceProtocol}=="00"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceClass}=="00"
ATTRS{bcdDevice}=="0400"
ATTRS{idProduct}=="6001"
ATTRS{idVendor}=="0403"
ATTRS{bMaxPower}==" 44mA"
ATTRS{bmAttributes}=="a0"
ATTRS{bConfigurationValue}=="1"
ATTRS{bNumInterfaces}==" 1"
ATTRS{configuration}==""
So I tried these udev rules:
DOES NOT WORK: KERNEL=="usb_device", SUBSYSTEMS=="usb", ATTRS{product}=="usb serial converter", ATTRS{manufacturer}=="FTDI", ATTRS{serial}=="FTCTWS1T", NAME="ttyUSB-GSM-630725830"
DOES NOT WORK: SUBSYSTEM=="usb_device", SUBSYSTEMS=="usb", ATTRS{product}=="usb serial converter", ATTRS{manufacturer}=="FTDI", ATTRS{serial}=="FTCTWS1T", NAME="ttyUSB-GSM-630725830"
works: SUBSYSTEMS=="usb", ATTRS{product}=="usb serial converter", ATTRS{manufacturer}=="FTDI", ATTRS{serial}=="FTCTWS1T", NAME="ttyUSB-GSM-630725830"
alternative (works):
SUBSYSTEMS=="usb", ATTRS{product}=="usb serial converter", ATTRS{manufacturer}=="FTDI", ATTRS{serial}=="FTCTWS1T", SYMLINK+="ttyUSB-GSM-630725830"
I tried this:
udevadm control --reload_rules
udevadm trigger --sybsystem-match=usb
to test my new udev rules without rebooting but that did not work. I had to force a reboot.
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So, even if my problem is solved now, I'd like to know:
1) why are my first 2 rules invalid?
2) how can I correctly reload udev rules without rebooting a system?
Thanks. |
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DawgG
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Joined: 17 Sep 2003
Posts: 874
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| Posted: Mon Aug 31, 2009 10:11 am Post subject: |
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glad it works now!
| Quote: | | why are my first 2 rules invalid? |
i think is neither part of KERNEL nor SUBSYSTEM in udev-rules.
| Quote: | | how can I correctly reload udev rules without rebooting a system? |
in my case (automounting usbdrives and executing a script on add and remove) (as root) did the trick.
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Vieri
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Joined: 18 Dec 2005
Posts: 907
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| Posted: Mon Aug 31, 2009 10:51 am Post subject: |
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| Thanks! |
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