SPRD_MBOX_FIFO_STS
fifo_sts = readl(base + SPRD_MBOX_FIFO_STS);
fifo_sts = readl(priv->inbox_base + SPRD_MBOX_FIFO_STS);
busy = readl(priv->inbox_base + SPRD_MBOX_FIFO_STS) &