serial: 8250: Name MSR literals

Add UART_MSR_STATUS_BITS for CD, RI, DSR & CTS. Use names for the
literal.

Don't make the define for combined flags part of UAPI.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20221125130509.8482-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 8676f8b..c870ee8 100644 (file)
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1268,9 +1268,9 @@ static void autoconfig(struct uart_8250_port *up)
         */
        if (!(port->flags & UPF_SKIP_TEST)) {
                serial8250_out_MCR(up, UART_MCR_LOOP | 0x0A);
-               status1 = serial_in(up, UART_MSR) & 0xF0;
+               status1 = serial_in(up, UART_MSR) & UART_MSR_STATUS_BITS;
                serial8250_out_MCR(up, save_mcr);
-               if (status1 != 0x90) {
+               if (status1 != (UART_MSR_DCD | UART_MSR_CTS)) {
                        spin_unlock_irqrestore(&port->lock, flags);
                        DEBUG_AUTOCONF("LOOP test failed (%02x) ",
                                       status1);

diff --git a/include/linux/serial.h b/include/linux/serial.h
index ad6e1c3..bfda927 100644 (file)
--- a/include/linux/serial.h
+++ b/include/linux/serial.h
@@ -28,6 +28,11 @@ static inline bool uart_lsr_tx_empty(u16 lsr)
        return (lsr & UART_LSR_BOTH_EMPTY) == UART_LSR_BOTH_EMPTY;
 }
 
+#define UART_MSR_STATUS_BITS   (UART_MSR_DCD | \
+                                UART_MSR_RI | \
+                                UART_MSR_DSR | \
+                                UART_MSR_CTS)
+
 /*
  * Counters of the input lines (CTS, DSR, RI, CD) interrupts
  */