diff --git a/drivers/tty/serial/8250/8250_fintek.c b/drivers/tty/serial/8250/8250_fintek.c
index ff4286bab791..b67e7a544935 100644
--- a/drivers/tty/serial/8250/8250_fintek.c
+++ b/drivers/tty/serial/8250/8250_fintek.c
@@ -21,6 +21,7 @@
 #define EXIT_KEY 0xAA
 #define CHIP_ID1  0x20
 #define CHIP_ID2  0x21
+#define CHIP_ID_F81865 0x0407
 #define CHIP_ID_F81866 0x1010
 #define CHIP_ID_F81216AD 0x1602
 #define CHIP_ID_F81216H 0x0501
@@ -130,6 +131,7 @@ static int fintek_8250_check_id(struct fintek_8250 *pdata)
 	chip |= sio_read_reg(pdata, CHIP_ID2) << 8;
 
 	switch (chip) {
+	case CHIP_ID_F81865:
 	case CHIP_ID_F81866:
 	case CHIP_ID_F81216AD:
 	case CHIP_ID_F81216H:
@@ -147,6 +149,7 @@ static int fintek_8250_get_ldn_range(struct fintek_8250 *pdata, int *min,
 				     int *max)
 {
 	switch (pdata->pid) {
+	case CHIP_ID_F81865:
 	case CHIP_ID_F81866:
 		*min = F81866_LDN_LOW;
 		*max = F81866_LDN_HIGH;
@@ -219,6 +222,8 @@ static void fintek_8250_set_irq_mode(struct fintek_8250 *pdata, bool is_level)
 	case CHIP_ID_F81866:
 		sio_write_mask_reg(pdata, F81866_FIFO_CTRL, F81866_IRQ_MODE1,
 				   0);
+		/* fall through */
+	case CHIP_ID_F81865:
 		sio_write_mask_reg(pdata, F81866_IRQ_MODE, F81866_IRQ_SHARE,
 				   F81866_IRQ_SHARE);
 		sio_write_mask_reg(pdata, F81866_IRQ_MODE, F81866_IRQ_MODE0,
@@ -311,6 +316,7 @@ static void fintek_8250_set_rs485_handler(struct uart_8250_port *uart)
 	case CHIP_ID_F81216AD:
 	case CHIP_ID_F81216H:
 	case CHIP_ID_F81866:
+	case CHIP_ID_F81865:
 		uart->port.rs485_config = fintek_8250_rs485_config;
 		break;