How can I create a device node from the init_module code of a Linux kernel module?

To have more control over the device numbers and the device creation, you could do the following steps (instead of register_chrdev()):

1. Call alloc_chrdev_region() to get a major number and a range of minor numbers to work with.
2. Create a device class for your devices with class_create().
3. For each device, call cdev_init() and cdev_add() to add the character device to the system.
4. For each device, call device_create(). As a result, among other things, Udev will create device nodes for your devices. There isn’t any need for mknod() or the like. device_create() also allows you to control the names of the devices.

There are probably many examples of this on the Internet, and one of them is here.