diff --git a/drivers/tty/serial/8250/8250_em.c b/drivers/tty/serial/8250/8250_em.c
index 7614ced9377e..25a9ecf26be6 100644
--- a/drivers/tty/serial/8250/8250_em.c
+++ b/drivers/tty/serial/8250/8250_em.c
@@ -18,6 +18,7 @@
 
 #define UART_DLL_EM 9
 #define UART_DLM_EM 10
+#define UART_HCR0_EM 11
 
 /*
  * A high value for UART_FCR_EM avoids overlapping with existing UART_*
@@ -26,11 +27,14 @@
 #define UART_FCR_EM 0x10003
 #define UART_FCR_EM_HW 3
 
+#define UART_HCR0_EM_SW_RESET	BIT(7) /* SW Reset */
+
 struct serial8250_em_priv {
 	int line;
 };
 
-static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
+static void serial8250_em_serial_out_helper(struct uart_port *p, int offset,
+					    int value)
 {
 	switch (offset) {
 	case UART_TX: /* TX @ 0x00 */
@@ -41,7 +45,6 @@ static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
 	case UART_SCR: /* SCR @ 0x20 (+1) */
 		writel(value, p->membase + ((offset + 1) << 2));
 		break;
-	case UART_FCR:
 	case UART_FCR_EM:
 		writel(value, p->membase + (UART_FCR_EM_HW << 2));
 		break;
@@ -50,6 +53,7 @@ static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
 		fallthrough;
 	case UART_DLL_EM: /* DLL @ 0x24 (+9) */
 	case UART_DLM_EM: /* DLM @ 0x28 (+9) */
+	case UART_HCR0_EM: /* HCR0 @ 0x2c */
 		writel(value, p->membase + (offset << 2));
 		break;
 	}
@@ -60,6 +64,7 @@ static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset)
 	switch (offset) {
 	case UART_RX: /* RX @ 0x00 */
 		return readb(p->membase);
+	case UART_LCR: /* LCR @ 0x10 (+1) */
 	case UART_MCR: /* MCR @ 0x14 (+1) */
 	case UART_LSR: /* LSR @ 0x18 (+1) */
 	case UART_MSR: /* MSR @ 0x1c (+1) */
@@ -71,11 +76,69 @@ static unsigned int serial8250_em_serial_in(struct uart_port *p, int offset)
 	case UART_IIR: /* IIR @ 0x08 */
 	case UART_DLL_EM: /* DLL @ 0x24 (+9) */
 	case UART_DLM_EM: /* DLM @ 0x28 (+9) */
+	case UART_HCR0_EM: /* HCR0 @ 0x2c */
 		return readl(p->membase + (offset << 2));
 	}
 	return 0;
 }
 
+static void serial8250_em_reg_update(struct uart_port *p, int off, int value)
+{
+	unsigned int ier, fcr, lcr, mcr, hcr0;
+
+	ier = serial8250_em_serial_in(p, UART_IER);
+	fcr = serial8250_em_serial_in(p, UART_FCR_EM);
+	lcr = serial8250_em_serial_in(p, UART_LCR);
+	mcr = serial8250_em_serial_in(p, UART_MCR);
+	hcr0 = serial8250_em_serial_in(p, UART_HCR0_EM);
+
+	serial8250_em_serial_out_helper(p, UART_FCR_EM, fcr |
+							UART_FCR_CLEAR_RCVR |
+							UART_FCR_CLEAR_XMIT);
+	serial8250_em_serial_out_helper(p, UART_HCR0_EM, hcr0 |
+							 UART_HCR0_EM_SW_RESET);
+	serial8250_em_serial_out_helper(p, UART_HCR0_EM, hcr0 &
+							 ~UART_HCR0_EM_SW_RESET);
+
+	switch (off) {
+	case UART_FCR_EM:
+		fcr = value;
+		break;
+	case UART_LCR:
+		lcr = value;
+		break;
+	case UART_MCR:
+		mcr = value;
+		break;
+	}
+
+	serial8250_em_serial_out_helper(p, UART_IER, ier);
+	serial8250_em_serial_out_helper(p, UART_FCR_EM, fcr);
+	serial8250_em_serial_out_helper(p, UART_MCR, mcr);
+	serial8250_em_serial_out_helper(p, UART_LCR, lcr);
+	serial8250_em_serial_out_helper(p, UART_HCR0_EM, hcr0);
+}
+
+static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
+{
+	switch (offset) {
+	case UART_TX:
+	case UART_SCR:
+	case UART_IER:
+	case UART_DLL_EM:
+	case UART_DLM_EM:
+		serial8250_em_serial_out_helper(p, offset, value);
+		break;
+	case UART_FCR:
+		serial8250_em_reg_update(p, UART_FCR_EM, value);
+		break;
+	case UART_LCR:
+	case UART_MCR:
+		serial8250_em_reg_update(p, offset, value);
+		break;
+	}
+}
+
 static int serial8250_em_serial_dl_read(struct uart_8250_port *up)
 {
 	return serial_in(up, UART_DLL_EM) | serial_in(up, UART_DLM_EM) << 8;