serial: 8250: extract serial8250_set_efr()

serial8250_do_set_termios() consists of many registers and up flags
settings. Extract all these into separate functions. This time, setting
of EFR for UART_CAP_EFR ports.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250611100319.186924-24-jirislaby@kernel.org
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 2c045a4369fcb8b228988a8039a2a2d68c935979..0f16398cc86faf89f6efbcd0f74fc7218703da4b 100644 (file)
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -2768,6 +2768,30 @@ static void serial8250_set_ier(struct uart_port *port, struct ktermios *termios)
        serial_port_out(port, UART_IER, up->ier);
 }
 
+static void serial8250_set_efr(struct uart_port *port, struct ktermios *termios)
+{
+       struct uart_8250_port *up = up_to_u8250p(port);
+       u8 efr_reg = UART_EFR;
+       u8 efr = 0;
+
+       if (!(up->capabilities & UART_CAP_EFR))
+               return;
+
+       /*
+        * TI16C752/Startech hardware flow control.  FIXME:
+        * - TI16C752 requires control thresholds to be set.
+        * - UART_MCR_RTS is ineffective if auto-RTS mode is enabled.
+        */
+       if (termios->c_cflag & CRTSCTS)
+               efr |= UART_EFR_CTS;
+
+       if (port->flags & UPF_EXAR_EFR)
+               efr_reg = UART_XR_EFR;
+
+       serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
+       serial_port_out(port, efr_reg, efr);
+}
+
 void
 serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
                          const struct ktermios *old)
@@ -2797,24 +2821,7 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
        uart_update_timeout(port, termios->c_cflag, baud);
        serial8250_set_errors_and_ignores(port, termios);
        serial8250_set_ier(port, termios);
-
-       if (up->capabilities & UART_CAP_EFR) {
-               unsigned char efr = 0;
-               /*
-                * TI16C752/Startech hardware flow control.  FIXME:
-                * - TI16C752 requires control thresholds to be set.
-                * - UART_MCR_RTS is ineffective if auto-RTS mode is enabled.
-                */
-               if (termios->c_cflag & CRTSCTS)
-                       efr |= UART_EFR_CTS;
-
-               serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
-               if (port->flags & UPF_EXAR_EFR)
-                       serial_port_out(port, UART_XR_EFR, efr);
-               else
-                       serial_port_out(port, UART_EFR, efr);
-       }
-
+       serial8250_set_efr(port, termios);
        serial8250_set_divisor(port, baud, quot, frac);
 
        /*