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, 26 insertions, 14 deletions

diff --git a/drivers/char/rocket.c b/drivers/char/rocket.c
index 584d791e84a6..4a4110e703a5 100644
--- a/drivers/char/rocket.c
+++ b/drivers/char/rocket.c
@@ -135,6 +135,7 @@ static int rcktpt_type[NUM_BOARDS];
 static int is_PCI[NUM_BOARDS];
 static rocketModel_t rocketModel[NUM_BOARDS];
 static int max_board;
+static const struct tty_port_operations rocket_port_ops;
 
 /*
  * The following arrays define the interrupt bits corresponding to each AIOP.
@@ -649,9 +650,8 @@ static void init_r_port(int board, int aiop, int chan, struct pci_dev *pci_dev)
         info->board = board;
         info->aiop = aiop;
         info->chan = chan;
-        info->port.closing_wait = 3000;
-        info->port.close_delay = 50;
-        init_waitqueue_head(&info->port.open_wait);
+        tty_port_init(&info->port);
+        info->port.ops = &rocket_port_ops;
         init_completion(&info->close_wait);
         info->flags &= ~ROCKET_MODE_MASK;
         switch (pc104[board][line]) {
@@ -864,11 +864,18 @@ static void configure_r_port(struct r_port *info,
         }
 }
 
+static int carrier_raised(struct tty_port *port)
+{
+        struct r_port *info = container_of(port, struct r_port, port);
+        return (sGetChanStatusLo(&info->channel) & CD_ACT) ? 1 : 0;
+}
+
 /*  info->port.count is considered critical, protected by spinlocks.  */
 static int block_til_ready(struct tty_struct *tty, struct file *filp,
                            struct r_port *info)
 {
         DECLARE_WAITQUEUE(wait, current);
+        struct tty_port *port = &info->port;
         int retval;
         int do_clocal = 0, extra_count = 0;
         unsigned long flags;
@@ -898,13 +905,13 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
 
         /*
          * Block waiting for the carrier detect and the line to become free.  While we are in
-         * this loop, info->port.count is dropped by one, so that rp_close() knows when to free things.
+         * this loop, port->count is dropped by one, so that rp_close() knows when to free things.
          * We restore it upon exit, either normal or abnormal.
          */
         retval = 0;
-        add_wait_queue(&info->port.open_wait, &wait);
+        add_wait_queue(&port->open_wait, &wait);
 #ifdef ROCKET_DEBUG_OPEN
-        printk(KERN_INFO "block_til_ready before block: ttyR%d, count = %d\n", info->line, info->port.count);
+        printk(KERN_INFO "block_til_ready before block: ttyR%d, count = %d\n", info->line, port->count);
 #endif
         spin_lock_irqsave(&info->slock, flags);
 
@@ -913,10 +920,10 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
 #else
         if (!tty_hung_up_p(filp)) {
                 extra_count = 1;
-                info->port.count--;
+                port->count--;
         }
 #endif
-        info->port.blocked_open++;
+        port->blocked_open++;
 
         spin_unlock_irqrestore(&info->slock, flags);
 
@@ -933,7 +940,8 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
                                 retval = -ERESTARTSYS;
                         break;
                 }
-                if (!(info->flags & ROCKET_CLOSING) && (do_clocal || (sGetChanStatusLo(&info->channel) & CD_ACT)))
+                if (!(info->flags & ROCKET_CLOSING) &&
+                        (do_clocal || tty_port_carrier_raised(port)))
                         break;
                 if (signal_pending(current)) {
                         retval = -ERESTARTSYS;
@@ -941,24 +949,24 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
                 }
 #ifdef ROCKET_DEBUG_OPEN
                 printk(KERN_INFO "block_til_ready blocking: ttyR%d, count = %d, flags=0x%0x\n",
-                     info->line, info->port.count, info->flags);
+                     info->line, port->count, info->flags);
 #endif
                 schedule();     /*  Don't hold spinlock here, will hang PC */
         }
         __set_current_state(TASK_RUNNING);
-        remove_wait_queue(&info->port.open_wait, &wait);
+        remove_wait_queue(&port->open_wait, &wait);
 
         spin_lock_irqsave(&info->slock, flags);
 
         if (extra_count)
-                info->port.count++;
-        info->port.blocked_open--;
+                port->count++;
+        port->blocked_open--;
 
         spin_unlock_irqrestore(&info->slock, flags);
 
 #ifdef ROCKET_DEBUG_OPEN
         printk(KERN_INFO "block_til_ready after blocking: ttyR%d, count = %d\n",
-               info->line, info->port.count);
+               info->line, port->count);
 #endif
         if (retval)
                 return retval;
@@ -2371,6 +2379,10 @@ static const struct tty_operations rocket_ops = {
         .tiocmset = rp_tiocmset,
 };
 
+static const struct tty_port_operations rocket_port_ops = {
+        .carrier_raised = carrier_raised,
+};
+
 /*
  * The module "startup" routine; it's run when the module is loaded.
  */