GMAC_CONTROL
u32 value = readl(ioaddr + GMAC_CONTROL);
writel(value, ioaddr + GMAC_CONTROL);
value = readl(ioaddr + GMAC_CONTROL);
writel(value | GMAC_CORE_INIT, ioaddr + GMAC_CONTROL);
u32 value = readl(ioaddr + GMAC_CONTROL);
writel(value, ioaddr + GMAC_CONTROL);
value = readl(ioaddr + GMAC_CONTROL);