tty_port: Add a port level carrier detect operation

This is the first step to generalising the various pieces of waiting logic
duplicated in all sorts of serial drivers.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 5 deletions

diff --git a/drivers/char/vme_scc.c b/drivers/char/vme_scc.c
index 1718b3c..d4e1534 100644
--- a/drivers/char/vme_scc.c
+++ b/drivers/char/vme_scc.c
@@ -69,7 +69,7 @@ static void scc_disable_tx_interrupts(void * ptr);
 static void scc_enable_tx_interrupts(void * ptr);
 static void scc_disable_rx_interrupts(void * ptr);
 static void scc_enable_rx_interrupts(void * ptr);
-static int  scc_get_CD(void * ptr);
+static int  scc_carrier_raised(struct tty_port *port);
 static void scc_shutdown_port(void * ptr);
 static int scc_set_real_termios(void  *ptr);
 static void scc_hungup(void  *ptr);
@@ -100,7 +100,6 @@ static struct real_driver scc_real_driver = {
         scc_enable_tx_interrupts,
         scc_disable_rx_interrupts,
         scc_enable_rx_interrupts,
-        scc_get_CD,
         scc_shutdown_port,
         scc_set_real_termios,
         scc_chars_in_buffer,
@@ -129,6 +128,10 @@ static const struct tty_operations scc_ops = {
 	.break_ctl = scc_break_ctl,
 };
 
+static const struct tty_port_operations scc_port_ops = {
+	.carrier_raised = scc_carrier_raised,
+};
+
 /*----------------------------------------------------------------------------
  * vme_scc_init() and support functions
  *---------------------------------------------------------------------------*/
@@ -176,6 +179,8 @@ static void scc_init_portstructs(void)
 
 	for (i = 0; i < 2; i++) {
 		port = scc_ports + i;
+		tty_port_init(&port->gs.port);
+		port->gs.port.ops = &scc_port_ops;
 		port->gs.magic = SCC_MAGIC;
 		port->gs.close_delay = HZ/2;
 		port->gs.closing_wait = 30 * HZ;
@@ -624,9 +629,9 @@ static void scc_enable_rx_interrupts(void *ptr)
 }
 
 
-static int scc_get_CD(void *ptr)
+static int scc_carrier_raised(struct tty_port *port)
 {
-	struct scc_port *port = ptr;
+	struct scc_port *scc = container_of(port, struct scc_port, gs.port);
 	unsigned channel = port->channel;
 
 	return !!(scc_last_status_reg[channel] & SR_DCD);
@@ -896,7 +901,7 @@ static int scc_open (struct tty_struct * tty, struct file * filp)
 		return retval;
 	}
 
-	port->c_dcd = scc_get_CD (port);
+	port->c_dcd = tty_port_carrier_raised(&port->gs.port);
 
 	scc_enable_rx_interrupts(port);