+
+#ifdef CONFIG_CLK
+ int ret;
+ struct clk clk;
+
+ ret = clk_get_by_index(dev, 0, &clk);
+ if (ret < 0)
+ return ret;
+
+ ret = clk_enable(&clk);
+ if (ret) {
+ dev_err(dev, "failed to enable clock\n");
+ return ret;
+ }
+#endif
+
+ /* Disable usart-> disable overrun-> enable usart */
+ clrbits_le32(&usart->cr1, USART_CR1_RE | USART_CR1_TE | USART_CR1_UE);
+ setbits_le32(&usart->cr3, USART_CR3_OVRDIS);