mxser: introduce and use start/stop_tx helpers

Starting and stopping TX is performed on many places in the driver. It
is repeated outb and info->IER modification.  Create few helpers
(__mxser_start_tx, mxser_start_tx, __mxser_stop_tx) and use them in the
code instead of open coding.

This should be a base for an uart driver for this device in the future.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-60-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 00363d9..e46974e 100644 (file)
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -418,6 +418,28 @@ static void mxser_process_txrx_fifo(struct mxser_port *info)
                }
 }
 
+static void __mxser_start_tx(struct mxser_port *info)
+{
+       outb(info->IER & ~UART_IER_THRI, info->ioaddr + UART_IER);
+       info->IER |= UART_IER_THRI;
+       outb(info->IER, info->ioaddr + UART_IER);
+}
+
+static void mxser_start_tx(struct mxser_port *info)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&info->slock, flags);
+       __mxser_start_tx(info);
+       spin_unlock_irqrestore(&info->slock, flags);
+}
+
+static void __mxser_stop_tx(struct mxser_port *info)
+{
+       info->IER &= ~UART_IER_THRI;
+       outb(info->IER, info->ioaddr + UART_IER);
+}
+
 static int mxser_carrier_raised(struct tty_port *port)
 {
        struct mxser_port *mp = container_of(port, struct mxser_port, port);
@@ -516,12 +538,8 @@ static void mxser_handle_cts(struct tty_struct *tty, struct mxser_port *info,
                        tty->hw_stopped = 0;
 
                        if (info->type != PORT_16550A &&
-                                       !info->board->must_hwid) {
-                               outb(info->IER & ~UART_IER_THRI,
-                                       info->ioaddr + UART_IER);
-                               info->IER |= UART_IER_THRI;
-                               outb(info->IER, info->ioaddr + UART_IER);
-                       }
+                                       !info->board->must_hwid)
+                               __mxser_start_tx(info);
                        tty_wakeup(tty);
                }
                return;
@@ -529,10 +547,8 @@ static void mxser_handle_cts(struct tty_struct *tty, struct mxser_port *info,
                return;
 
        tty->hw_stopped = 1;
-       if (info->type != PORT_16550A && !info->board->must_hwid) {
-               info->IER &= ~UART_IER_THRI;
-               outb(info->IER, info->ioaddr + UART_IER);
-       }
+       if (info->type != PORT_16550A && !info->board->must_hwid)
+               __mxser_stop_tx(info);
 }
 
 /*
@@ -947,16 +963,9 @@ static int mxser_write(struct tty_struct *tty, const unsigned char *buf, int cou
        }
 
        if (info->xmit_cnt && !tty->flow.stopped) {
-               if (!tty->hw_stopped ||
-                               (info->type == PORT_16550A) ||
-                               (info->board->must_hwid)) {
-                       spin_lock_irqsave(&info->slock, flags);
-                       outb(info->IER & ~UART_IER_THRI, info->ioaddr +
-                                       UART_IER);
-                       info->IER |= UART_IER_THRI;
-                       outb(info->IER, info->ioaddr + UART_IER);
-                       spin_unlock_irqrestore(&info->slock, flags);
-               }
+               if (!tty->hw_stopped || info->type == PORT_16550A ||
+                               info->board->must_hwid)
+                       mxser_start_tx(info);
        }
        return total;
 }
@@ -985,20 +994,13 @@ static int mxser_put_char(struct tty_struct *tty, unsigned char ch)
 static void mxser_flush_chars(struct tty_struct *tty)
 {
        struct mxser_port *info = tty->driver_data;
-       unsigned long flags;
 
        if (info->xmit_cnt <= 0 || tty->flow.stopped || !info->port.xmit_buf ||
                        (tty->hw_stopped && info->type != PORT_16550A &&
                         !info->board->must_hwid))
                return;
 
-       spin_lock_irqsave(&info->slock, flags);
-
-       outb(info->IER & ~UART_IER_THRI, info->ioaddr + UART_IER);
-       info->IER |= UART_IER_THRI;
-       outb(info->IER, info->ioaddr + UART_IER);
-
-       spin_unlock_irqrestore(&info->slock, flags);
+       mxser_start_tx(info);
 }
 
 static unsigned int mxser_write_room(struct tty_struct *tty)
@@ -1399,10 +1401,8 @@ static void mxser_stop(struct tty_struct *tty)
        unsigned long flags;
 
        spin_lock_irqsave(&info->slock, flags);
-       if (info->IER & UART_IER_THRI) {
-               info->IER &= ~UART_IER_THRI;
-               outb(info->IER, info->ioaddr + UART_IER);
-       }
+       if (info->IER & UART_IER_THRI)
+               __mxser_stop_tx(info);
        spin_unlock_irqrestore(&info->slock, flags);
 }
 
@@ -1412,11 +1412,8 @@ static void mxser_start(struct tty_struct *tty)
        unsigned long flags;
 
        spin_lock_irqsave(&info->slock, flags);
-       if (info->xmit_cnt && info->port.xmit_buf) {
-               outb(info->IER & ~UART_IER_THRI, info->ioaddr + UART_IER);
-               info->IER |= UART_IER_THRI;
-               outb(info->IER, info->ioaddr + UART_IER);
-       }
+       if (info->xmit_cnt && info->port.xmit_buf)
+               __mxser_start_tx(info);
        spin_unlock_irqrestore(&info->slock, flags);
 }
 
@@ -1659,8 +1656,7 @@ static void mxser_transmit_chars(struct tty_struct *tty, struct mxser_port *port
                        (tty->hw_stopped &&
                        (port->type != PORT_16550A) &&
                        (!port->board->must_hwid))) {
-               port->IER &= ~UART_IER_THRI;
-               outb(port->IER, port->ioaddr + UART_IER);
+               __mxser_stop_tx(port);
                return;
        }
 
@@ -1679,10 +1675,8 @@ static void mxser_transmit_chars(struct tty_struct *tty, struct mxser_port *port
        if (port->xmit_cnt < WAKEUP_CHARS)
                tty_wakeup(tty);
 
-       if (port->xmit_cnt <= 0) {
-               port->IER &= ~UART_IER_THRI;
-               outb(port->IER, port->ioaddr + UART_IER);
-       }
+       if (port->xmit_cnt <= 0)
+               __mxser_stop_tx(port);
 }
 
 static bool mxser_port_isr(struct mxser_port *port)