MBOX_MODE_REG
if (readl(base + MBOX_MODE_REG) & MBOX_STATE_IDLE) {
writel_relaxed(MBOX_AUTOMATIC_ACK, base + MBOX_MODE_REG);
if (readl(base + MBOX_MODE_REG) & MBOX_STATE_READY)
ret = readx_poll_timeout_atomic(readl, base + MBOX_MODE_REG,
mode = readl(mbox->base + MBOX_MODE_REG(slot));
writel(mode, mbox->base + MBOX_MODE_REG(slot));
state = readl(mbox->base + MBOX_MODE_REG(mchan->slot));
status = readl(mbox->base + MBOX_MODE_REG(slot));
writel(status, mbox->base + MBOX_MODE_REG(slot));