Change default resolution for device files

I wrote my gpio driver and registered it on the system with udev. This created all my device files, but the permission they created is 600. How can I change this default permission to 666 or whatever. As I need to start my program by reading this file using sudo.

Should I write any rules in udev .. please explain. Or I need to change the permission of my program in my program itself to root.

Update: my udev rules.d contains

40-scratch.rules

:

ATTRS{idVendor}=="0694", ATTRS{idProduct}=="0003", SUBSYSTEMS=="usb", ACTION=="add", MODE="0666", GROUP="plugdev"

      

        
        
        
      

    

and 99-input.rules

:

SUBSYSTEM=="input", GROUP="input", MODE="0660"

      

        
        
        
      

    

and udev.conf

:

udev_log="err"