diff --git a/drivers/serial/serial_stm32x7.c b/drivers/serial/serial_stm32x7.c
index 05c73da2301245cbe9190017e4b40446827103b3..bf118a78cf9dc17151148fa35dd8cb1c320c68f7 100644
--- a/drivers/serial/serial_stm32x7.c
+++ b/drivers/serial/serial_stm32x7.c
@@ -19,16 +19,9 @@ static int stm32_serial_setbrg(struct udevice *dev, int baudrate)
 {
 	struct stm32x7_serial_platdata *plat = dev->platdata;
 	struct stm32_usart *const usart = plat->base;
-	u32  clock, int_div, mantissa, fraction, oversampling;
+	u32 int_div, mantissa, fraction, oversampling;
 
-	if (((u32)usart & STM32_BUS_MASK) == APB1_PERIPH_BASE)
-		clock = clock_get(CLOCK_APB1);
-	else if (((u32)usart & STM32_BUS_MASK) == APB2_PERIPH_BASE)
-		clock = clock_get(CLOCK_APB2);
-	else
-		return -EINVAL;
-
-	int_div = DIV_ROUND_CLOSEST(clock, baudrate);
+	int_div = DIV_ROUND_CLOSEST(plat->clock_rate, baudrate);
 
 	if (int_div < 16) {
 		oversampling = 8;
@@ -101,6 +94,12 @@ static int stm32_serial_probe(struct udevice *dev)
 	}
 #endif
 
+	plat->clock_rate = clk_get_rate(&clk);
+	if (plat->clock_rate < 0) {
+		clk_disable(&clk);
+		return plat->clock_rate;
+	};
+
 	/* 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);
diff --git a/drivers/serial/serial_stm32x7.h b/drivers/serial/serial_stm32x7.h
index 42b05f14b52a682163ad1c28a379adc787a40b4d..9fe37af5cc998db1d3bb563fefe679a3a5364ca7 100644
--- a/drivers/serial/serial_stm32x7.h
+++ b/drivers/serial/serial_stm32x7.h
@@ -25,7 +25,7 @@ struct stm32_usart {
 /* Information about a serial port */
 struct stm32x7_serial_platdata {
 	struct stm32_usart *base;  /* address of registers in physical memory */
-	unsigned int clock;
+	unsigned long int clock_rate;
 };
 
 #define USART_CR1_OVER8			(1 << 15)