Initial file dump from open source releaseHEADmaster

1 files changed, 169 insertions, 0 deletions

diff --git a/drivers/staging/dgrp/dgrp_common.c b/drivers/staging/dgrp/dgrp_common.c
new file mode 100644
index 00000000..9a9b4562
--- /dev/null
+++ b/drivers/staging/dgrp/dgrp_common.c
@@ -0,0 +1,169 @@
+/*
+ *
+ * Copyright 1999 Digi International (www.digi.com)
+ *     James Puzzo <jamesp at digi dot com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
+ * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ */
+
+/*
+ *
+ *  Filename:
+ *
+ *     dgrp_common.c
+ *
+ *  Description:
+ *
+ *     Definitions of global variables and functions which are either
+ *     shared by the tty, mon, and net drivers; or which cross them
+ *     functionally (like the poller).
+ *
+ *  Author:
+ *
+ *     James A. Puzzo
+ *
+ */
+
+#include <linux/errno.h>
+#include <linux/tty.h>
+#include <linux/sched.h>
+#include <linux/cred.h>
+
+#include "dgrp_common.h"
+
+/**
+ * dgrp_carrier -- check for carrier change state and act
+ * @ch: struct ch_struct *
+ */
+void dgrp_carrier(struct ch_struct *ch)
+{
+	struct nd_struct *nd;
+
+	int virt_carrier = 0;
+	int phys_carrier = 0;
+
+	/* fix case when the tty has already closed. */
+
+	if (!ch)
+		return;
+	nd  = ch->ch_nd;
+	if (!nd)
+		return;
+
+	/*
+	 *  If we are currently waiting to determine the status of the port,
+	 *  we don't yet know the state of the modem lines.  As a result,
+	 *  we ignore state changes when we are waiting for the modem lines
+	 *  to be established.  We know, as a result of code in dgrp_net_ops,
+	 *  that we will be called again immediately following the reception
+	 *  of the status message with the true modem status flags in it.
+	 */
+	if (ch->ch_expect & RR_STATUS)
+		return;
+
+	/*
+	 * If CH_HANGUP is set, we gotta keep trying to get all the processes
+	 * that have the port open to close the port.
+	 * So lets just keep sending a hangup every time we get here.
+	 */
+	if ((ch->ch_flag & CH_HANGUP) &&
+	    (ch->ch_tun.un_open_count > 0))
+		tty_hangup(ch->ch_tun.un_tty);
+
+	/*
+	 *  Compute the effective state of both the physical and virtual
+	 *  senses of carrier.
+	 */
+
+	if (ch->ch_s_mlast & DM_CD)
+		phys_carrier = 1;
+
+	if ((ch->ch_s_mlast & DM_CD) ||
+	    (ch->ch_digi.digi_flags & DIGI_FORCEDCD) ||
+	    (ch->ch_flag & CH_CLOCAL))
+		virt_carrier = 1;
+
+	/*
+	 *  Test for a VIRTUAL carrier transition to HIGH.
+	 *
+	 *  The CH_HANGUP condition is intended to prevent any action
+	 *  except for close.  As a result, we ignore positive carrier
+	 *  transitions during CH_HANGUP.
+	 */
+	if (((ch->ch_flag & CH_HANGUP)  == 0) &&
+	    ((ch->ch_flag & CH_VIRT_CD) == 0) &&
+	    (virt_carrier == 1)) {
+		/*
+		 * When carrier rises, wake any threads waiting
+		 * for carrier in the open routine.
+		 */
+		nd->nd_tx_work = 1;
+
+		if (waitqueue_active(&ch->ch_flag_wait))
+			wake_up_interruptible(&ch->ch_flag_wait);
+	}
+
+	/*
+	 *  Test for a PHYSICAL transition to low, so long as we aren't
+	 *  currently ignoring physical transitions (which is what "virtual
+	 *  carrier" indicates).
+	 *
+	 *  The transition of the virtual carrier to low really doesn't
+	 *  matter... it really only means "ignore carrier state", not
+	 *  "make pretend that carrier is there".
+	 */
+	if ((virt_carrier == 0) &&
+	    ((ch->ch_flag & CH_PHYS_CD) != 0) &&
+	    (phys_carrier == 0)) {
+		/*
+		 * When carrier drops:
+		 *
+		 *   Do a Hard Hangup if that is called for.
+		 *
+		 *   Drop carrier on all open units.
+		 *
+		 *   Flush queues, waking up any task waiting in the
+		 *   line discipline.
+		 *
+		 *   Send a hangup to the control terminal.
+		 *
+		 *   Enable all select calls.
+		 */
+
+		nd->nd_tx_work = 1;
+
+		ch->ch_flag &= ~(CH_LOW | CH_EMPTY | CH_DRAIN | CH_INPUT);
+
+		if (waitqueue_active(&ch->ch_flag_wait))
+			wake_up_interruptible(&ch->ch_flag_wait);
+
+		if (ch->ch_tun.un_open_count > 0)
+			tty_hangup(ch->ch_tun.un_tty);
+
+		if (ch->ch_pun.un_open_count > 0)
+			tty_hangup(ch->ch_pun.un_tty);
+	}
+
+	/*
+	 *  Make sure that our cached values reflect the current reality.
+	 */
+	if (virt_carrier == 1)
+		ch->ch_flag |= CH_VIRT_CD;
+	else
+		ch->ch_flag &= ~CH_VIRT_CD;
+
+	if (phys_carrier == 1)
+		ch->ch_flag |= CH_PHYS_CD;
+	else
+		ch->ch_flag &= ~CH_PHYS_CD;
+
+}