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, 14 insertions, 13 deletions

diff --git a/drivers/char/sx.c b/drivers/char/sx.c
index ba4e86281fbf..a71bc58abe7f 100644
--- a/drivers/char/sx.c
+++ b/drivers/char/sx.c
@@ -279,7 +279,7 @@ static void sx_disable_tx_interrupts(void *ptr);
 static void sx_enable_tx_interrupts(void *ptr);
 static void sx_disable_rx_interrupts(void *ptr);
 static void sx_enable_rx_interrupts(void *ptr);
-static int sx_get_CD(void *ptr);
+static int sx_carrier_raised(struct tty_port *port);
 static void sx_shutdown_port(void *ptr);
 static int sx_set_real_termios(void *ptr);
 static void sx_close(void *ptr);
@@ -360,7 +360,6 @@ static struct real_driver sx_real_driver = {
         sx_enable_tx_interrupts,
         sx_disable_rx_interrupts,
         sx_enable_rx_interrupts,
-        sx_get_CD,
         sx_shutdown_port,
         sx_set_real_termios,
         sx_chars_in_buffer,
@@ -791,7 +790,7 @@ static int sx_getsignals(struct sx_port *port)
         sx_dprintk(SX_DEBUG_MODEMSIGNALS, "getsignals: %d/%d  (%d/%d) "
                         "%02x/%02x\n",
                         (o_stat & OP_DTR) != 0, (o_stat & OP_RTS) != 0,
-                        port->c_dcd, sx_get_CD(port),
+                        port->c_dcd, tty_port_carrier_raised(&port->gs.port),
                         sx_read_channel_byte(port, hi_ip),
                         sx_read_channel_byte(port, hi_state));
 
@@ -1190,7 +1189,7 @@ static inline void sx_check_modem_signals(struct sx_port *port)
 
         hi_state = sx_read_channel_byte(port, hi_state);
         sx_dprintk(SX_DEBUG_MODEMSIGNALS, "Checking modem signals (%d/%d)\n",
-                        port->c_dcd, sx_get_CD(port));
+                        port->c_dcd, tty_port_carrier_raised(&port->gs.port));
 
         if (hi_state & ST_BREAK) {
                 hi_state &= ~ST_BREAK;
@@ -1202,11 +1201,11 @@ static inline void sx_check_modem_signals(struct sx_port *port)
                 hi_state &= ~ST_DCD;
                 sx_dprintk(SX_DEBUG_MODEMSIGNALS, "got a DCD change.\n");
                 sx_write_channel_byte(port, hi_state, hi_state);
-                c_dcd = sx_get_CD(port);
+                c_dcd = tty_port_carrier_raised(&port->gs.port);
                 sx_dprintk(SX_DEBUG_MODEMSIGNALS, "DCD is now %d\n", c_dcd);
                 if (c_dcd != port->c_dcd) {
                         port->c_dcd = c_dcd;
-                        if (sx_get_CD(port)) {
+                        if (tty_port_carrier_raised(&port->gs.port)) {
                                 /* DCD went UP */
                                 if ((sx_read_channel_byte(port, hi_hstat) !=
                                                 HS_IDLE_CLOSED) &&
@@ -1415,13 +1414,10 @@ static void sx_enable_rx_interrupts(void *ptr)
 }
 
 /* Jeez. Isn't this simple? */
-static int sx_get_CD(void *ptr)
+static int sx_carrier_raised(struct tty_port *port)
 {
-        struct sx_port *port = ptr;
-        func_enter2();
-
-        func_exit();
-        return ((sx_read_channel_byte(port, hi_ip) & IP_DCD) != 0);
+        struct sx_port *sp = container_of(port, struct sx_port, gs.port);
+        return ((sx_read_channel_byte(sp, hi_ip) & IP_DCD) != 0);
 }
 
 /* Jeez. Isn't this simple? */
@@ -1536,7 +1532,7 @@ static int sx_open(struct tty_struct *tty, struct file *filp)
         }
         /* tty->low_latency = 1; */
 
-        port->c_dcd = sx_get_CD(port);
+        port->c_dcd = sx_carrier_raised(&port->gs.port);
         sx_dprintk(SX_DEBUG_OPEN, "at open: cd=%d\n", port->c_dcd);
 
         func_exit();
@@ -2354,6 +2350,10 @@ static const struct tty_operations sx_ops = {
         .tiocmset = sx_tiocmset,
 };
 
+static const struct tty_port_operations sx_port_ops = {
+        .carrier_raised = sx_carrier_raised,
+};
+
 static int sx_init_drivers(void)
 {
         int error;
@@ -2410,6 +2410,7 @@ static int sx_init_portstructs(int nboards, int nports)
                 for (j = 0; j < boards[i].nports; j++) {
                         sx_dprintk(SX_DEBUG_INIT, "initing port %d\n", j);
                         tty_port_init(&port->gs.port);
+                        port->gs.port.ops = &sx_port_ops;
                         port->gs.magic = SX_MAGIC;
                         port->gs.close_delay = HZ / 2;
                         port->gs.closing_wait = 30 * HZ;