[PATCH v1 1/1] serial: 8250_port: Introduce UART_IIR_FIFO_ENABLED_16750

[Andy Shevchenko]

The UART_IIR_64BYTE_FIFO is always being used in conjunction with
UART_IIR_FIFO_ENABLED. Introduce a joined UART_IIR_FIFO_ENABLED_16750
definition and use it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
 drivers/tty/serial/8250/8250_port.c | 11 +++++------
 include/uapi/linux/serial_reg.h     |  1 +
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index fb891b67968f..a064698c2be0 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1008,12 +1008,11 @@ static void autoconfig_16550a(struct uart_8250_port *up)
 			serial_out(up, UART_LCR, 0);
 			serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
 				   UART_FCR7_64BYTE);
-			status1 = serial_in(up, UART_IIR) & (UART_IIR_64BYTE_FIFO |
-							     UART_IIR_FIFO_ENABLED);
+			status1 = serial_in(up, UART_IIR) & UART_IIR_FIFO_ENABLED_16750;
 			serial_out(up, UART_FCR, 0);
 			serial_out(up, UART_LCR, 0);
 
-			if (status1 == (UART_IIR_64BYTE_FIFO | UART_IIR_FIFO_ENABLED))
+			if (status1 == UART_IIR_FIFO_ENABLED_16750)
 				up->port.type = PORT_16550A_FSL64;
 			else
 				DEBUG_AUTOCONF("Motorola 8xxx DUART ");
@@ -1081,12 +1080,12 @@ static void autoconfig_16550a(struct uart_8250_port *up)
 	 */
 	serial_out(up, UART_LCR, 0);
 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
-	status1 = serial_in(up, UART_IIR) & (UART_IIR_64BYTE_FIFO | UART_IIR_FIFO_ENABLED);
+	status1 = serial_in(up, UART_IIR) & UART_IIR_FIFO_ENABLED_16750;
 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
 
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR7_64BYTE);
-	status2 = serial_in(up, UART_IIR) & (UART_IIR_64BYTE_FIFO | UART_IIR_FIFO_ENABLED);
+	status2 = serial_in(up, UART_IIR) & UART_IIR_FIFO_ENABLED_16750;
 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
 
 	serial_out(up, UART_LCR, 0);
@@ -1094,7 +1093,7 @@ static void autoconfig_16550a(struct uart_8250_port *up)
 	DEBUG_AUTOCONF("iir1=%d iir2=%d ", status1, status2);
 
 	if (status1 == UART_IIR_FIFO_ENABLED_16550A &&
-	    status2 == (UART_IIR_64BYTE_FIFO | UART_IIR_FIFO_ENABLED_16550A)) {
+	    status2 == UART_IIR_FIFO_ENABLED_16750) {
 		up->port.type = PORT_16750;
 		up->capabilities |= UART_CAP_AFE | UART_CAP_SLEEP;
 		return;
diff --git a/include/uapi/linux/serial_reg.h b/include/uapi/linux/serial_reg.h
index 08b3527e1b93..9c987b04e2d0 100644
--- a/include/uapi/linux/serial_reg.h
+++ b/include/uapi/linux/serial_reg.h
@@ -49,6 +49,7 @@
 #define  UART_IIR_FIFO_ENABLED_8250	0x00	/* 8250: no FIFO */
 #define  UART_IIR_FIFO_ENABLED_16550	0x80	/* 16550: (broken/unusable) FIFO */
 #define  UART_IIR_FIFO_ENABLED_16550A	0xc0	/* 16550A: FIFO enabled */
+#define  UART_IIR_FIFO_ENABLED_16750	0xe0	/* 16750: 64 bytes FIFO enabled */
 
 #define UART_FCR	2	/* Out: FIFO Control Register */
 #define UART_FCR_ENABLE_FIFO	0x01 /* Enable the FIFO */
-- 
2.40.0.1.gaa8946217a0b