From 31f35939d1d9bcfb3099b32c67b896d2792603f9 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Fri, 2 Jan 2009 13:45:05 +0000 Subject: 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 Signed-off-by: Linus Torvalds --- drivers/char/synclink.c | 61 +++++++++++++++++++++++++++++++++---------------- 1 file changed, 41 insertions(+), 20 deletions(-) (limited to 'drivers/char/synclink.c') diff --git a/drivers/char/synclink.c b/drivers/char/synclink.c index 500f5176b6b..fb2e6b5e0ef 100644 --- a/drivers/char/synclink.c +++ b/drivers/char/synclink.c @@ -3281,6 +3281,23 @@ static void mgsl_hangup(struct tty_struct *tty) } /* end of mgsl_hangup() */ +/* + * carrier_raised() + * + * Return true if carrier is raised + */ + +static int carrier_raised(struct tty_port *port) +{ + unsigned long flags; + struct mgsl_struct *info = container_of(port, struct mgsl_struct, port); + + spin_lock_irqsave(&info->irq_spinlock, flags); + usc_get_serial_signals(info); + spin_unlock_irqrestore(&info->irq_spinlock, flags); + return (info->serial_signals & SerialSignal_DCD) ? 1 : 0; +} + /* block_til_ready() * * Block the current process until the specified port @@ -3302,6 +3319,8 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp, bool do_clocal = false; bool extra_count = false; unsigned long flags; + int dcd; + struct tty_port *port = &info->port; if (debug_level >= DEBUG_LEVEL_INFO) printk("%s(%d):block_til_ready on %s\n", @@ -3309,7 +3328,7 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp, if (filp->f_flags & O_NONBLOCK || tty->flags & (1 << TTY_IO_ERROR)){ /* nonblock mode is set or port is not enabled */ - info->port.flags |= ASYNC_NORMAL_ACTIVE; + port->flags |= ASYNC_NORMAL_ACTIVE; return 0; } @@ -3318,25 +3337,25 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp, /* Wait for carrier detect and the line to become * free (i.e., not in use by the callout). While we are in - * this loop, info->port.count is dropped by one, so that + * this loop, port->count is dropped by one, so that * mgsl_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); if (debug_level >= DEBUG_LEVEL_INFO) printk("%s(%d):block_til_ready before block on %s count=%d\n", - __FILE__,__LINE__, tty->driver->name, info->port.count ); + __FILE__,__LINE__, tty->driver->name, port->count ); spin_lock_irqsave(&info->irq_spinlock, flags); if (!tty_hung_up_p(filp)) { extra_count = true; - info->port.count--; + port->count--; } spin_unlock_irqrestore(&info->irq_spinlock, flags); - info->port.blocked_open++; + port->blocked_open++; while (1) { if (tty->termios->c_cflag & CBAUD) { @@ -3348,20 +3367,16 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp, set_current_state(TASK_INTERRUPTIBLE); - if (tty_hung_up_p(filp) || !(info->port.flags & ASYNC_INITIALIZED)){ - retval = (info->port.flags & ASYNC_HUP_NOTIFY) ? + if (tty_hung_up_p(filp) || !(port->flags & ASYNC_INITIALIZED)){ + retval = (port->flags & ASYNC_HUP_NOTIFY) ? -EAGAIN : -ERESTARTSYS; break; } - spin_lock_irqsave(&info->irq_spinlock,flags); - usc_get_serial_signals(info); - spin_unlock_irqrestore(&info->irq_spinlock,flags); + dcd = tty_port_carrier_raised(&info->port); - if (!(info->port.flags & ASYNC_CLOSING) && - (do_clocal || (info->serial_signals & SerialSignal_DCD)) ) { + if (!(port->flags & ASYNC_CLOSING) && (do_clocal || dcd)) break; - } if (signal_pending(current)) { retval = -ERESTARTSYS; @@ -3370,24 +3385,24 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp, if (debug_level >= DEBUG_LEVEL_INFO) printk("%s(%d):block_til_ready blocking on %s count=%d\n", - __FILE__,__LINE__, tty->driver->name, info->port.count ); + __FILE__,__LINE__, tty->driver->name, port->count ); schedule(); } set_current_state(TASK_RUNNING); - remove_wait_queue(&info->port.open_wait, &wait); + remove_wait_queue(&port->open_wait, &wait); if (extra_count) - info->port.count++; - info->port.blocked_open--; + port->count++; + port->blocked_open--; if (debug_level >= DEBUG_LEVEL_INFO) printk("%s(%d):block_til_ready after blocking on %s count=%d\n", - __FILE__,__LINE__, tty->driver->name, info->port.count ); + __FILE__,__LINE__, tty->driver->name, port->count ); if (!retval) - info->port.flags |= ASYNC_NORMAL_ACTIVE; + port->flags |= ASYNC_NORMAL_ACTIVE; return retval; @@ -4304,6 +4319,11 @@ static void mgsl_add_device( struct mgsl_struct *info ) } /* end of mgsl_add_device() */ +static const struct tty_port_operations mgsl_port_ops = { + .carrier_raised = carrier_raised, +}; + + /* mgsl_allocate_device() * * Allocate and initialize a device instance structure @@ -4322,6 +4342,7 @@ static struct mgsl_struct* mgsl_allocate_device(void) printk("Error can't allocate device instance data\n"); } else { tty_port_init(&info->port); + info->port.ops = &mgsl_port_ops; info->magic = MGSL_MAGIC; INIT_WORK(&info->task, mgsl_bh_handler); info->max_frame_size = 4096; -- cgit v1.2.3