diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 1e8fe44a7099..5418708f4631 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -167,12 +167,12 @@ static unsigned int __maybe_unused serial_icr_read(struct uart_8250_port *up,
 
 void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p);
 
-static inline int serial_dl_read(struct uart_8250_port *up)
+static inline u32 serial_dl_read(struct uart_8250_port *up)
 {
 	return up->dl_read(up);
 }
 
-static inline void serial_dl_write(struct uart_8250_port *up, int value)
+static inline void serial_dl_write(struct uart_8250_port *up, u32 value)
 {
 	up->dl_write(up, value);
 }
diff --git a/drivers/tty/serial/8250/8250_em.c b/drivers/tty/serial/8250/8250_em.c
index 25a9ecf26be6..ef5019e944ea 100644
--- a/drivers/tty/serial/8250/8250_em.c
+++ b/drivers/tty/serial/8250/8250_em.c
@@ -139,12 +139,12 @@ static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
 	}
 }
 
-static int serial8250_em_serial_dl_read(struct uart_8250_port *up)
+static u32 serial8250_em_serial_dl_read(struct uart_8250_port *up)
 {
 	return serial_in(up, UART_DLL_EM) | serial_in(up, UART_DLM_EM) << 8;
 }
 
-static void serial8250_em_serial_dl_write(struct uart_8250_port *up, int value)
+static void serial8250_em_serial_dl_write(struct uart_8250_port *up, u32 value)
 {
 	serial_out(up, UART_DLL_EM, value & 0xff);
 	serial_out(up, UART_DLM_EM, value >> 8 & 0xff);
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index fe8d79c4ae95..0622c11f0064 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -325,7 +325,7 @@ static const struct serial8250_config uart_config[] = {
 };
 
 /* Uart divisor latch read */
-static int default_serial_dl_read(struct uart_8250_port *up)
+static u32 default_serial_dl_read(struct uart_8250_port *up)
 {
 	/* Assign these in pieces to truncate any bits above 7.  */
 	unsigned char dll = serial_in(up, UART_DLL);
@@ -335,7 +335,7 @@ static int default_serial_dl_read(struct uart_8250_port *up)
 }
 
 /* Uart divisor latch write */
-static void default_serial_dl_write(struct uart_8250_port *up, int value)
+static void default_serial_dl_write(struct uart_8250_port *up, u32 value)
 {
 	serial_out(up, UART_DLL, value & 0xff);
 	serial_out(up, UART_DLM, value >> 8 & 0xff);
@@ -389,12 +389,12 @@ void au_serial_out(struct uart_port *p, int offset, int value)
 }
 
 /* Au1x00 haven't got a standard divisor latch */
-static int au_serial_dl_read(struct uart_8250_port *up)
+static u32 au_serial_dl_read(struct uart_8250_port *up)
 {
 	return __raw_readl(up->port.membase + 0x28);
 }
 
-static void au_serial_dl_write(struct uart_8250_port *up, int value)
+static void au_serial_dl_write(struct uart_8250_port *up, u32 value)
 {
 	__raw_writel(value, up->port.membase + 0x28);
 }
@@ -847,7 +847,7 @@ static void disable_rsa(struct uart_8250_port *up)
 static int size_fifo(struct uart_8250_port *up)
 {
 	unsigned char old_fcr, old_mcr, old_lcr;
-	unsigned short old_dl;
+	unsigned int old_dl;
 	int count;
 
 	old_lcr = serial_in(up, UART_LCR);
diff --git a/drivers/tty/serial/8250/8250_pxa.c b/drivers/tty/serial/8250/8250_pxa.c
index 795e55142d4c..28b341f602c6 100644
--- a/drivers/tty/serial/8250/8250_pxa.c
+++ b/drivers/tty/serial/8250/8250_pxa.c
@@ -60,7 +60,7 @@ static const struct of_device_id serial_pxa_dt_ids[] = {
 MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);
 
 /* Uart divisor latch write */
-static void serial_pxa_dl_write(struct uart_8250_port *up, int value)
+static void serial_pxa_dl_write(struct uart_8250_port *up, u32 value)
 {
 	unsigned int dll;
 
diff --git a/drivers/tty/serial/8250/8250_uniphier.c b/drivers/tty/serial/8250/8250_uniphier.c
index a2978abab0db..a405155264b1 100644
--- a/drivers/tty/serial/8250/8250_uniphier.c
+++ b/drivers/tty/serial/8250/8250_uniphier.c
@@ -145,12 +145,12 @@ static void uniphier_serial_out(struct uart_port *p, int offset, int value)
  * The divisor latch register exists at different address.
  * Override dl_read/write callbacks.
  */
-static int uniphier_serial_dl_read(struct uart_8250_port *up)
+static u32 uniphier_serial_dl_read(struct uart_8250_port *up)
 {
 	return readl(up->port.membase + UNIPHIER_UART_DLR);
 }
 
-static void uniphier_serial_dl_write(struct uart_8250_port *up, int value)
+static void uniphier_serial_dl_write(struct uart_8250_port *up, u32 value)
 {
 	writel(value, up->port.membase + UNIPHIER_UART_DLR);
 }
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index 6f78f302d272..7b5d558e4e0c 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -129,8 +129,8 @@ struct uart_8250_port {
 	const struct uart_8250_ops *ops;
 
 	/* 8250 specific callbacks */
-	int			(*dl_read)(struct uart_8250_port *);
-	void			(*dl_write)(struct uart_8250_port *, int);
+	u32			(*dl_read)(struct uart_8250_port *up);
+	void			(*dl_write)(struct uart_8250_port *up, u32 value);
 
 	struct uart_8250_em485 *em485;
 	void			(*rs485_start_tx)(struct uart_8250_port *);
