pci.c

#define MY_PCI_DOMAIN_NUM 0x0001
#define MY_PCI_BUS_NUM 0x00

#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci-ats.h>
#include <linux/pci-acpi.h>
#include <linux/pci-aspm.h>
#include <asm/pci.h>

int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val){
  return 0;
}
int pci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val){
  return 0;
}

struct pci_ops my_pci_ops = {};
extern struct bus_type pci_bus_type;

MODULE_LICENSE("Dual BSD/GPL");

struct pci_sysdata my_pci_sd = {};
struct pci_dev my_pci_dev = {};

static int hello_init(void){
    struct pci_bus* my_pci_bus;
    
    memset (&my_pci_sd, 0, sizeof (my_pci_sd));
    my_pci_sd.domain = MY_PCI_DOMAIN_NUM;
    my_pci_sd.node = -1;
    
    printk(KERN_ALERT "Hello, world\n");
    memset (&my_pci_ops, 0, sizeof (my_pci_ops));
    my_pci_ops.read = pci_read;
    my_pci_ops.write = pci_write;
      
    my_pci_bus = pci_scan_bus(MY_PCI_BUS_NUM, &my_pci_ops, &my_pci_sd);
    if(my_pci_bus){
       printk(KERN_INFO "Successfully created MY PCI bus");
    }
    return 0;
}

static void hello_exit(void)
{
    printk(KERN_ALERT "Goodbye, cruel world\n");
}

module_init(hello_init);
module_exit(hello_exit);