Hi All.
I have a SD/MMC reader over PCI, which displays the following (amongst
others) when we do "lspci -vv" :
#########################################################
Region 0: Memory at e2c20000 (32-bit, non-prefetchable) [size=512]
#########################################################
Above shows that e2c20000 is the physical (base-)address of BAR0.
Now, in the device driver, I do the following :
########################################################
.....
struct pci_dev *ptr;
void __iomem *bar0_ptr;
......
......
pci_request_region(ptr, 0, "ajay_sd_mmc_BAR0_region");
bar0_ptr = pci_iomap(ptr, 0, pci_resource_len(ptr, 0));
printk("Base virtual-address = [%p]\n", bar0_ptr);
printk("Base physical-address = [%p]\n", virt_to_phys(bar0_ptr));
printk("Base bus-address = [%p]\n", virt_to_bus(bar0_ptr));
....
########################################################
I have removed error-checking, but I confirm that pci_request_region()
and pci_iomap calls are successful.
Now, in the 3 printk's, none of the value is printed as e2c20000.
I was expecting that the 2nd result, of virt_to_phys() translation,
would be equal to the base-address of BAR0 register, as reported by
lspci.
What am I missing?
Will be grateful for pointers.
Thanks and Regards,
Ajay
