staging: Add dgrp driver for Digi Realport devices
This is based on dgrp-1.9 available from
ftp://ftp1.digi.com/support/beta/linux/dgrp/dgrp-1.9.tgz
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/dgrp/dgrp_common.c b/drivers/staging/dgrp/dgrp_common.c
new file mode 100644
index 0000000..fce74e7
--- /dev/null
+++ b/drivers/staging/dgrp/dgrp_common.c
@@ -0,0 +1,200 @@
+/*
+ *
+ * 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;
+
+}
+
+/**
+ * dgrp_chk_perm() -- check permissions for net device
+ * @inode: pointer to inode structure for the net communication device
+ * @op: operation to be tested
+ *
+ * The file permissions and ownerships are tested to determine whether
+ * the operation "op" is permitted on the file pointed to by the inode.
+ * Returns 0 if the operation is permitted, -EACCESS otherwise
+ */
+int dgrp_chk_perm(int mode, int op)
+{
+ if (!current_euid())
+ mode >>= 6;
+ else if (in_egroup_p(0))
+ mode >>= 3;
+
+ if ((mode & op & 0007) == op)
+ return 0;
+
+ if (capable(CAP_SYS_ADMIN))
+ return 0;
+
+ return -EACCES;
+}
+
+/* dgrp_chk_perm wrapper for permission call in struct inode_operations */
+int dgrp_inode_permission(struct inode *inode, int op)
+{
+ return dgrp_chk_perm(inode->i_mode, op);
+}