The allocation of PCI resources is done in the
probe() function, and usually an extra
xxx_create() function is written for this
purpose.
In the case of PCI devices, you have to call at first
pci_enable_device() function before
allocating resources. Also, you need to set the proper PCI DMA
mask to limit the accessed i/o range. In some cases, you might
need to call pci_set_master() function,
too.
Suppose the 28bit mask, and the code to be added would be like: