serial: add port helpers

We can make this the same as the ones that will be needed by the tty_port
helper logic that we want to move to but still call them from the existing
code base.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 37 insertions, 14 deletions

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 424b1c7e50c4..2379045e0871 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1501,6 +1501,34 @@ static void uart_update_termios(struct tty_struct *tty,
         }
 }
 
+static int uart_carrier_raised(struct tty_port *port)
+{
+        struct uart_state *state = container_of(port, struct uart_state, port);
+        struct uart_port *uport = state->uart_port;
+        int mctrl;
+        mutex_lock(&port->mutex);
+        spin_lock_irq(&uport->lock);
+        uport->ops->enable_ms(uport);
+        mctrl = uport->ops->get_mctrl(uport);
+        spin_unlock_irq(&uport->lock);
+        mutex_unlock(&port->mutex);
+        if (mctrl & TIOCM_CAR)
+                return 1;
+        return 0;
+}
+
+static void uart_dtr_rts(struct tty_port *port, int onoff)
+{
+        struct uart_state *state = container_of(port, struct uart_state, port);
+        struct uart_port *uport = state->uart_port;
+        mutex_lock(&port->mutex);
+        if (onoff)
+                uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
+        else
+                uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS);
+        mutex_unlock(&port->mutex);
+}
+
 /*
  * Block the open until the port is ready.  We must be called with
  * the per-port semaphore held.
@@ -1509,9 +1537,7 @@ static int
 uart_block_til_ready(struct file *filp, struct uart_state *state)
 {
         DECLARE_WAITQUEUE(wait, current);
-        struct uart_port *uport = state->uart_port;
         struct tty_port *port = &state->port;
-        unsigned int mctrl;
         unsigned long flags;
 
         spin_lock_irqsave(&port->lock, flags);
@@ -1555,23 +1581,14 @@ uart_block_til_ready(struct file *filp, struct uart_state *state)
                  * not set RTS here - we want to make sure we catch
                  * the data from the modem.
                  */
-                if (port->tty->termios->c_cflag & CBAUD) {
-                        mutex_lock(&port->mutex);
-                        uart_set_mctrl(uport, TIOCM_DTR);
-                        mutex_unlock(&port->mutex);
-                }
+                if (port->tty->termios->c_cflag & CBAUD)
+                        tty_port_raise_dtr_rts(port);
 
                 /*
                  * and wait for the carrier to indicate that the
                  * modem is ready for us.
                  */
-                mutex_lock(&port->mutex);
-                spin_lock_irq(&uport->lock);
-                uport->ops->enable_ms(uport);
-                mctrl = uport->ops->get_mctrl(uport);
-                spin_unlock_irq(&uport->lock);
-                mutex_unlock(&port->mutex);
-                if (mctrl & TIOCM_CAR)
+                if (tty_port_carrier_raised(port))
                         break;
 
                 schedule();
@@ -2349,6 +2366,11 @@ static const struct tty_operations uart_ops = {
 #endif
 };
 
+static const struct tty_port_operations uart_port_ops = {
+        .carrier_raised = uart_carrier_raised,
+        .dtr_rts        = uart_dtr_rts,
+};
+
 /**
  *      uart_register_driver - register a driver with the uart core layer
  *      @drv: low level driver structure
@@ -2405,6 +2427,7 @@ int uart_register_driver(struct uart_driver *drv)
                 struct tty_port *port = &state->port;
 
                 tty_port_init(port);
+                port->ops = &uart_port_ops;
                 port->close_delay     = 500;    /* .5 seconds */
                 port->closing_wait    = 30000;  /* 30 seconds */
                 tasklet_init(&state->tlet, uart_tasklet_action,