STM32_VREFBUF_CSR
ret = readl_relaxed(priv->base + STM32_VREFBUF_CSR) & STM32_ENVR;
val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);
val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);
ret = readl_poll_timeout(priv->base + STM32_VREFBUF_CSR, val,
val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);
val = readl_relaxed(priv->base + STM32_VREFBUF_CSR);
writel_relaxed(val, priv->base + STM32_VREFBUF_CSR);