TG3PCI_CLOCK_CTRL
clock_ctrl = tr32(TG3PCI_CLOCK_CTRL);
tw32(TG3PCI_CLOCK_CTRL, tp->pci_clock_ctrl);
tw32_carefully(TG3PCI_CLOCK_CTRL,
tw32_carefully(TG3PCI_CLOCK_CTRL,
tw32_carefully(TG3PCI_CLOCK_CTRL, clock_ctrl);
tw32_carefully(TG3PCI_CLOCK_CTRL, tp->pci_clock_ctrl);
tw32(TG3PCI_CLOCK_CTRL, 0);
uint32_t ccval = tr32(TG3PCI_CLOCK_CTRL) & 0x1f;