I have a driver supporting basicNIC/RDMA running in linux kernel 6.2, consisting of 2 ko files, which using auxiliary_device/driver structure, like this:

/* basicNIC.ko: */
struct pci_device{
    struct auxiliary device RDMA_dev;
    ...
} NIC_dev;

struct pci_driver {
   ...
}NIC_drv;

/* RDMA.ko: */
struct auxiliary driver {
    ...
}RDMA_drv

I want to make my driver support linux kernel 4.x, which does not support auxiliary_device/driver structure. Can i replace it with platform_device/driver? If so, what are the pros and cons?

I read the code about auxiliary_bus patch.Exactly I think it is just a simplified version of platform_bus, but i am not very sure because i am a newbie.