BUS_MODE
smsc9420_reg_write(pd, BUS_MODE, bus_mode);
smsc9420_reg_write(pd, BUS_MODE, BUS_MODE_SWR_);
smsc9420_reg_read(pd, BUS_MODE);
if (smsc9420_reg_read(pd, BUS_MODE) & BUS_MODE_SWR_)
#define CURRENT_BUS_MODE(s) ((u8) (s & BUS_MODE) ? BUS_MODE_PCIX : BUS_MODE_PCI)