Udev rule for input device

Question

I have a camera device that has an input device listed under /dev/input. I would like to add that input device to the group plugdev.

When I plug in the camera:

[  704.406837] input: See3CAM_CU51 as /devices/pci0000:00/0000:00:14.0/usb4/4-2/4-2:1.0/input/input21
[  705.157657] hid-generic 0003:2560:C152.0007: hiddev0,hidraw4: USB HID v1.11 Device [e-con Systems See3CAM_CU51] on usb-0000:00:1

It's now symlinked under /dev/input/by-id

0 lrwxrwxrwx 1 root root 10 Aug 31 10:50 usb-e-con_Systems_See3CAM_CU51_172A0202-event-if00 -> ../event20

However, event20 has the following permissions:

0 crw-rw---- 1 root input 13, 84 Aug 31 10:50 event20

I've written udev rules for the hiddevice itself with success, but for some reason, I can't get the rule right for the input device. Here's what I've tried:

KERNEL=="input", ATTR{name}=="See3CAM_CU51", MODE="0666" GROUP="plugdev"

But it does not appear to work. There's not a huge deal of examples of changing the ownership of input devices out there (that I've found at least).

Update:

When I change my udev rule to

    KERNEL=="input", MODE="0666" GROUP="plugdev"

that is, I leave out the device name, all my input devices in /dev/input have the correct permissions.

So basically, I'm saying "every input device gets set to mode 0666, and belong to the plugdev group", which works. But adding the ATTR{name}== breaks it.

Here's the output of udevadm info:

udevadm info -a -p /devices/pci0000:00/0000:00:14.0/usb4/4-2/4-2:1.0/input/input21

looking at device '/devices/pci0000:00/0000:00:14.0/usb4/4-2/4-2:1.0/input/input21':
KERNEL=="input21"
SUBSYSTEM=="input"
DRIVER==""
ATTR{name}=="See3CAM_CU51"
ATTR{phys}=="usb-0000:00:14.0-2/button"
ATTR{properties}=="0"
ATTR{uniq}==""

It should be working, I have the correct name set for the device, what stupid mistake am I making?

Answer 1

udev rules support string matching, you're probably looking for:

ACTION=="...", KERNEL=="input[0-9]*", SUBSYSTEM=="input", ...

to match on the specific action for any inputN devices, then you can add your ATTR filter(s) to select the specific device.