21 files changed, 10912 insertions, 19 deletions

diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
index 0f51a158ef7..d805eef1191 100644
--- a/drivers/staging/Kconfig
+++ b/drivers/staging/Kconfig
@@ -142,4 +142,6 @@ source "drivers/staging/ced1401/Kconfig"
 
 source "drivers/staging/imx-drm/Kconfig"
 
+source "drivers/staging/dgrp/Kconfig"
+
 endif # STAGING
diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
index f4b2bc41f1d..76e2ebd596f 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -63,3 +63,4 @@ obj-$(CONFIG_ZCACHE2)		+= ramster/
 obj-$(CONFIG_NET_VENDOR_SILICOM)	+= silicom/
 obj-$(CONFIG_CED1401)		+= ced1401/
 obj-$(CONFIG_DRM_IMX)		+= imx-drm/
+obj-$(CONFIG_DGRP)		+= dgrp/
diff --git a/drivers/staging/dgrp/Kconfig b/drivers/staging/dgrp/Kconfig
new file mode 100644
index 00000000000..39f4bb65ec8
--- /dev/null
+++ b/drivers/staging/dgrp/Kconfig
@@ -0,0 +1,9 @@
+config DGRP
+       tristate "Digi Realport driver"
+       default n
+       depends on SYSFS
+       ---help---
+       Support for Digi Realport devices.  These devices allow you to
+       access remote serial ports as if they are local tty devices.  This
+       will build the kernel driver, you will still need the userspace
+       component to make your Realport device work.
diff --git a/drivers/staging/dgrp/Makefile b/drivers/staging/dgrp/Makefile
new file mode 100644
index 00000000000..d9c3b88d716
--- /dev/null
+++ b/drivers/staging/dgrp/Makefile
@@ -0,0 +1,12 @@
+obj-$(CONFIG_DGRP) += dgrp.o
+
+dgrp-y := 			\
+	dgrp_common.o 		\
+	dgrp_dpa_ops.o 		\
+	dgrp_driver.o 		\
+	dgrp_mon_ops.o 	 	\
+	dgrp_net_ops.o 		\
+	dgrp_ports_ops.o 	\
+	dgrp_specproc.o 	\
+	dgrp_tty.o 		\
+	dgrp_sysfs.o
diff --git a/drivers/staging/dgrp/README b/drivers/staging/dgrp/README
new file mode 100644
index 00000000000..1d8aaee270e
--- /dev/null
+++ b/drivers/staging/dgrp/README
@@ -0,0 +1,2 @@
+The user space code to work with this driver is located at
+https://github.com/wfp5p/dgrp-utils
diff --git a/drivers/staging/dgrp/TODO b/drivers/staging/dgrp/TODO
new file mode 100644
index 00000000000..3ef2611bc6d
--- /dev/null
+++ b/drivers/staging/dgrp/TODO
@@ -0,0 +1,13 @@
+- Use configfs for config stuff.  This will require changes to the
+  user space code.
+
+- dgrp_send() and dgrp_receive() could use some refactoring
+
+- Don't automatically create CHAN_MAX (64) channel array entries for
+  every device as many devices are going to have much less than 64
+  channels.
+
+- The locking needs to be checked.  It seems haphazardly done in most
+  places.
+
+- Check Kconfig dependencies
diff --git a/drivers/staging/dgrp/dgrp_common.c b/drivers/staging/dgrp/dgrp_common.c
new file mode 100644
index 00000000000..fce74e7fb83
--- /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);
+}
diff --git a/drivers/staging/dgrp/dgrp_common.h b/drivers/staging/dgrp/dgrp_common.h
new file mode 100644
index 00000000000..05ff338471a
--- /dev/null
+++ b/drivers/staging/dgrp/dgrp_common.h
@@ -0,0 +1,208 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+#ifndef __DGRP_COMMON_H
+#define __DGRP_COMMON_H
+
+#define DIGI_VERSION "1.9-29"
+
+#include <linux/fs.h>
+#include <linux/timer.h>
+#include "drp.h"
+
+#define DGRP_TTIME 100
+#define DGRP_RTIME 100
+
+/************************************************************************
+ * All global storage allocation.
+ ************************************************************************/
+
+extern int dgrp_rawreadok;  /* Allow raw writing of input */
+extern int dgrp_register_cudevices; /* enable legacy cu devices */
+extern int dgrp_register_prdevices; /* enable transparent print devices */
+extern int dgrp_poll_tick;          /* Poll interval - in ms */
+
+extern struct list_head nd_struct_list;
+
+struct dgrp_poll_data {
+	spinlock_t poll_lock;
+	struct timer_list timer;
+	int poll_tick;
+	ulong poll_round;	/* Timer rouding factor */
+	long node_active_count;
+};
+
+extern struct dgrp_poll_data dgrp_poll_data;
+extern void dgrp_poll_handler(unsigned long arg);
+
+/* from dgrp_mon_ops.c */
+extern void dgrp_register_mon_hook(struct proc_dir_entry *de);
+
+/* from dgrp_tty.c */
+extern int dgrp_tty_init(struct nd_struct *nd);
+extern void dgrp_tty_uninit(struct nd_struct *nd);
+
+/* from dgrp_ports_ops.c */
+extern void dgrp_register_ports_hook(struct proc_dir_entry *de);
+
+/* from dgrp_net_ops.c */
+extern void dgrp_register_net_hook(struct proc_dir_entry *de);
+
+/* from dgrp_dpa_ops.c */
+extern void dgrp_register_dpa_hook(struct proc_dir_entry *de);
+extern void dgrp_dpa_data(struct nd_struct *, int, u8 *, int);
+
+/* from dgrp_sysfs.c */
+extern void dgrp_create_class_sysfs_files(void);
+extern void dgrp_remove_class_sysfs_files(void);
+
+extern void dgrp_create_node_class_sysfs_files(struct nd_struct *nd);
+extern void dgrp_remove_node_class_sysfs_files(struct nd_struct *nd);
+
+extern void dgrp_create_tty_sysfs(struct un_struct *un, struct device *c);
+extern void dgrp_remove_tty_sysfs(struct device *c);
+
+/* from dgrp_specproc.c */
+/*
+ *  The list of DGRP entries with r/w capabilities.  These
+ *  magic numbers are used for identification purposes.
+ */
+enum {
+	DGRP_CONFIG = 1,	/* Configure portservers */
+	DGRP_NETDIR = 2,	/* Directory for "net" devices */
+	DGRP_MONDIR = 3,	/* Directory for "mon" devices */
+	DGRP_PORTSDIR = 4,	/* Directory for "ports" devices */
+	DGRP_INFO = 5,		/* Get info. about the running module */
+	DGRP_NODEINFO = 6,	/* Get info. about the configured nodes */
+	DGRP_DPADIR = 7,	/* Directory for the "dpa" devices */
+};
+
+/*
+ *  Directions for proc handlers
+ */
+enum {
+	INBOUND = 1,		/* Data being written to kernel */
+	OUTBOUND = 2,		/* Data being read from the kernel */
+};
+
+/**
+ * dgrp_proc_entry: structure for dgrp proc dirs
+ * @id: ID number associated with this particular entry.  Should be
+ *    unique across all of DGRP.
+ * @name: text name associated with the /proc entry
+ * @mode: file access permisssions for the /proc entry
+ * @child: pointer to table describing a subdirectory for this entry
+ * @de: pointer to directory entry for this object once registered.  Used
+ *    to grab the handle of the object for unregistration
+ * @excl_sem: semaphore to provide exclusive to struct
+ * @excl_cnt: counter of current accesses
+ *
+ *  Each entry in a DGRP proc directory is described with a
+ *  dgrp_proc_entry structure.  A collection of these
+ *  entries (in an array) represents the members associated
+ *  with a particular /proc directory, and is referred to
+ *  as a table.  All tables are terminated by an entry with
+ *  zeros for every member.
+ */
+struct dgrp_proc_entry {
+	int                  id;          /* Integer identifier */
+	const char        *name;          /* ASCII identifier */
+	mode_t             mode;          /* File access permissions */
+	struct dgrp_proc_entry *child;    /* Child pointer */
+
+	/* file ops to use, pass NULL to use default */
+	struct file_operations *proc_file_ops;
+
+	struct proc_dir_entry *de;        /* proc entry pointer */
+	struct semaphore   excl_sem;      /* Protects exclusive access var */
+	int                excl_cnt;      /* Counts number of curr accesses */
+};
+
+extern void dgrp_unregister_proc(void);
+extern void dgrp_register_proc(void);
+
+/*-----------------------------------------------------------------------*
+ *
+ *  Declarations for common operations:
+ *
+ *      (either used by more than one of net, mon, or tty,
+ *       or in interrupt context (i.e. the poller))
+ *
+ *-----------------------------------------------------------------------*/
+
+void dgrp_carrier(struct ch_struct *ch);
+extern int dgrp_inode_permission(struct inode *inode, int op);
+extern int dgrp_chk_perm(int mode, int op);
+
+
+/*
+ *  ID manipulation macros (where c1 & c2 are characters, i is
+ *  a long integer, and s is a character array of at least three members
+ */
+
+static inline void ID_TO_CHAR(long i, char *s)
+{
+	s[0] = ((i & 0xff00)>>8);
+	s[1] = (i & 0xff);
+	s[2] = 0;
+}
+
+static inline long CHAR_TO_ID(char *s)
+{
+	return ((s[0] & 0xff) << 8) | (s[1] & 0xff);
+}
+
+static inline struct nd_struct *nd_struct_get(long major)
+{
+	struct nd_struct *nd;
+
+	list_for_each_entry(nd, &nd_struct_list, list) {
+		if (major == nd->nd_major)
+			return nd;
+	}
+
+	return NULL;
+}
+
+static inline int nd_struct_add(struct nd_struct *entry)
+{
+	struct nd_struct *ptr;
+
+	ptr = nd_struct_get(entry->nd_major);
+
+	if (ptr)
+		return -EBUSY;
+
+	list_add_tail(&entry->list, &nd_struct_list);
+
+	return 0;
+}
+
+static inline int nd_struct_del(struct nd_struct *entry)
+{
+	struct nd_struct *nd;
+
+	nd = nd_struct_get(entry->nd_major);
+
+	if (!nd)
+		return -ENODEV;
+
+	list_del(&nd->list);
+	return 0;
+}
+
+#endif /* __DGRP_COMMON_H */
diff --git a/drivers/staging/dgrp/dgrp_dpa_ops.c b/drivers/staging/dgrp/dgrp_dpa_ops.c
new file mode 100644
index 00000000000..49e670915e5
--- /dev/null
+++ b/drivers/staging/dgrp/dgrp_dpa_ops.c
@@ -0,0 +1,556 @@
+/*
+ *
+ * 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_dpa_ops.c
+ *
+ *  Description:
+ *
+ *     Handle the file operations required for the "dpa" devices.
+ *     Includes those functions required to register the "dpa" devices
+ *     in "/proc".
+ *
+ *  Author:
+ *
+ *     James A. Puzzo
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/tty.h>
+#include <linux/poll.h>
+#include <linux/cred.h>
+#include <linux/sched.h>
+#include <linux/ratelimit.h>
+#include <asm/unaligned.h>
+
+#include "dgrp_common.h"
+
+/* File operation declarations */
+static int dgrp_dpa_open(struct inode *, struct file *);
+static int dgrp_dpa_release(struct inode *, struct file *);
+static ssize_t dgrp_dpa_read(struct file *, char __user *, size_t, loff_t *);
+static long dgrp_dpa_ioctl(struct file *file, unsigned int cmd,
+			   unsigned long arg);
+static unsigned int dgrp_dpa_select(struct file *, struct poll_table_struct *);
+
+static const struct file_operations dpa_ops = {
+	.owner   =  THIS_MODULE,
+	.read    =  dgrp_dpa_read,
+	.poll    =  dgrp_dpa_select,
+	.unlocked_ioctl =  dgrp_dpa_ioctl,
+	.open    =  dgrp_dpa_open,
+	.release =  dgrp_dpa_release,
+};
+
+static struct inode_operations dpa_inode_ops = {
+	.permission = dgrp_inode_permission
+};
+
+
+
+struct digi_node {
+	uint	nd_state;		/* Node state: 1 = up, 0 = down. */
+	uint	nd_chan_count;		/* Number of channels found */
+	uint	nd_tx_byte;		/* Tx data count */
+	uint	nd_rx_byte;		/* RX data count */
+	u8	nd_ps_desc[MAX_DESC_LEN]; /* Description from PS */
+};
+
+#define DIGI_GETNODE      (('d'<<8) | 249)	/* get board info */
+
+
+struct digi_chan {
+	uint	ch_port;	/* Port number to get info on */
+	uint	ch_open;	/* 1 if open, 0 if not */
+	uint	ch_txcount;	/* TX data count  */
+	uint	ch_rxcount;	/* RX data count  */
+	uint	ch_s_brate;	/* Realport BRATE */
+	uint	ch_s_estat;	/* Realport ELAST */
+	uint	ch_s_cflag;	/* Realport CFLAG */
+	uint	ch_s_iflag;	/* Realport IFLAG */
+	uint	ch_s_oflag;	/* Realport OFLAG */
+	uint	ch_s_xflag;	/* Realport XFLAG */
+	uint	ch_s_mstat;	/* Realport MLAST */
+};
+
+#define DIGI_GETCHAN      (('d'<<8) | 248)	/* get channel info */
+
+
+struct digi_vpd {
+	int vpd_len;
+	char vpd_data[VPDSIZE];
+};
+
+#define DIGI_GETVPD       (('d'<<8) | 246)	/* get VPD info */
+
+
+struct digi_debug {
+	int onoff;
+	int port;
+};
+
+#define DIGI_SETDEBUG      (('d'<<8) | 247)	/* set debug info */
+
+
+void dgrp_register_dpa_hook(struct proc_dir_entry *de)
+{
+	struct nd_struct *node = de->data;
+
+	de->proc_iops = &dpa_inode_ops;
+	de->proc_fops = &dpa_ops;
+
+	node->nd_dpa_de = de;
+	spin_lock_init(&node->nd_dpa_lock);
+}
+
+/*
+ * dgrp_dpa_open -- open the DPA device for a particular PortServer
+ */
+static int dgrp_dpa_open(struct inode *inode, struct file *file)
+{
+	struct nd_struct *nd;
+	int rtn = 0;
+
+	struct proc_dir_entry *de;
+
+	rtn = try_module_get(THIS_MODULE);
+	if (!rtn)
+		return -ENXIO;
+
+	rtn = 0;
+
+	if (!capable(CAP_SYS_ADMIN)) {
+		rtn = -EPERM;
+		goto done;
+	}
+
+	/*
+	 *  Make sure that the "private_data" field hasn't already been used.
+	 */
+	if (file->private_data) {
+		rtn = -EINVAL;
+		goto done;
+	}
+
+	/*
+	 *  Get the node pointer, and fail if it doesn't exist.
+	 */
+	de = PDE(inode);
+	if (!de) {
+		rtn = -ENXIO;
+		goto done;
+	}
+	nd = (struct nd_struct *)de->data;
+	if (!nd) {
+		rtn = -ENXIO;
+		goto done;
+	}
+
+	file->private_data = (void *) nd;
+
+	/*
+	 * Allocate the DPA buffer.
+	 */
+
+	if (nd->nd_dpa_buf) {
+		rtn = -EBUSY;
+	} else {
+		nd->nd_dpa_buf = kmalloc(DPA_MAX, GFP_KERNEL);
+
+		if (!nd->nd_dpa_buf) {
+			rtn = -ENOMEM;
+		} else {
+			nd->nd_dpa_out = 0;
+			nd->nd_dpa_in = 0;
+			nd->nd_dpa_lbolt = jiffies;
+		}
+	}
+
+done:
+
+	if (rtn)
+		module_put(THIS_MODULE);
+	return rtn;
+}
+
+/*
+ * dgrp_dpa_release -- close the DPA device for a particular PortServer
+ */
+static int dgrp_dpa_release(struct inode *inode, struct file *file)
+{
+	struct nd_struct *nd;
+	u8 *buf;
+	unsigned long lock_flags;
+
+	/*
+	 *  Get the node pointer, and quit if it doesn't exist.
+	 */
+	nd = (struct nd_struct *)(file->private_data);
+	if (!nd)
+		goto done;
+
+	/*
+	 *  Free the dpa buffer.
+	 */
+
+	spin_lock_irqsave(&nd->nd_dpa_lock, lock_flags);
+
+	buf = nd->nd_dpa_buf;
+
+	nd->nd_dpa_buf = NULL;
+	nd->nd_dpa_out = nd->nd_dpa_in;
+
+	/*
+	 *  Wakeup any thread waiting for buffer space.
+	 */
+
+	if (nd->nd_dpa_flag & DPA_WAIT_SPACE) {
+		nd->nd_dpa_flag &= ~DPA_WAIT_SPACE;
+		wake_up_interruptible(&nd->nd_dpa_wqueue);
+	}
+
+	spin_unlock_irqrestore(&nd->nd_dpa_lock, lock_flags);
+
+	kfree(buf);
+
+done:
+	module_put(THIS_MODULE);
+	file->private_data = NULL;
+	return 0;
+}
+
+/*
+ * dgrp_dpa_read
+ *
+ * Copy data from the monitoring buffer to the user, freeing space
+ * in the monitoring buffer for more messages
+ */
+static ssize_t dgrp_dpa_read(struct file *file, char __user *buf, size_t count,
+			     loff_t *ppos)
+{
+	struct nd_struct *nd;
+	int n;
+	int r;
+	int offset = 0;
+	int res = 0;
+	ssize_t rtn;
+	unsigned long lock_flags;
+
+	/*
+	 *  Get the node pointer, and quit if it doesn't exist.
+	 */
+	nd = (struct nd_struct *)(file->private_data);
+	if (!nd)
+		return -ENXIO;
+
+	/*
+	 *  Wait for some data to appear in the buffer.
+	 */
+
+	spin_lock_irqsave(&nd->nd_dpa_lock, lock_flags);
+
+	for (;;) {
+		n = (nd->nd_dpa_in - nd->nd_dpa_out) & DPA_MASK;
+
+		if (n != 0)
+			break;
+
+		nd->nd_dpa_flag |= DPA_WAIT_DATA;
+
+		spin_unlock_irqrestore(&nd->nd_dpa_lock, lock_flags);
+
+		/*
+		 * Go to sleep waiting until the condition becomes true.
+		 */
+		rtn = wait_event_interruptible(nd->nd_dpa_wqueue,
+			((nd->nd_dpa_flag & DPA_WAIT_DATA) == 0));
+
+		if (rtn)
+			return rtn;
+
+		spin_lock_irqsave(&nd->nd_dpa_lock, lock_flags);
+	}
+
+	/*
+	 *  Read whatever is there.
+	 */
+
+	if (n > count)
+		n = count;
+
+	res = n;
+
+	r = DPA_MAX - nd->nd_dpa_out;
+
+	if (r <= n) {
+
+		spin_unlock_irqrestore(&nd->nd_dpa_lock, lock_flags);
+		rtn = copy_to_user((void __user *)buf,
+				   nd->nd_dpa_buf + nd->nd_dpa_out, r);
+		spin_lock_irqsave(&nd->nd_dpa_lock, lock_flags);
+
+		if (rtn) {
+			rtn = -EFAULT;
+			goto done;
+		}
+
+		nd->nd_dpa_out = 0;
+		n -= r;
+		offset = r;
+	}
+
+	spin_unlock_irqrestore(&nd->nd_dpa_lock, lock_flags);
+	rtn = copy_to_user((void __user *)buf + offset,
+			   nd->nd_dpa_buf + nd->nd_dpa_out, n);
+	spin_lock_irqsave(&nd->nd_dpa_lock, lock_flags);
+
+	if (rtn) {
+		rtn = -EFAULT;
+		goto done;
+	}
+
+	nd->nd_dpa_out += n;
+
+	*ppos += res;
+
+	rtn = res;
+
+	/*
+	 *  Wakeup any thread waiting for buffer space.
+	 */
+
+	n = (nd->nd_dpa_in - nd->nd_dpa_out) & DPA_MASK;
+
+	if (nd->nd_dpa_flag & DPA_WAIT_SPACE &&
+	    (DPA_MAX - n) > DPA_HIGH_WATER) {
+		nd->nd_dpa_flag &= ~DPA_WAIT_SPACE;
+		wake_up_interruptible(&nd->nd_dpa_wqueue);
+	}
+
+ done:
+	spin_unlock_irqrestore(&nd->nd_dpa_lock, lock_flags);
+	return rtn;
+}
+
+static unsigned int dgrp_dpa_select(struct file *file,
+				    struct poll_table_struct *table)
+{
+	unsigned int retval = 0;
+	struct nd_struct *nd = file->private_data;
+
+	if (nd->nd_dpa_out != nd->nd_dpa_in)
+		retval |= POLLIN | POLLRDNORM; /* Conditionally readable */
+
+	retval |= POLLOUT | POLLWRNORM;        /* Always writeable */
+
+	return retval;
+}
+
+static long dgrp_dpa_ioctl(struct file *file, unsigned int cmd,
+			   unsigned long arg)
+{
+
+	struct nd_struct  *nd;
+	struct digi_chan getchan;
+	struct digi_node getnode;
+	struct ch_struct *ch;
+	struct digi_debug setdebug;
+	struct digi_vpd vpd;
+	unsigned int port;
+	void __user *uarg = (void __user *) arg;
+
+	nd = file->private_data;
+
+	switch (cmd) {
+	case DIGI_GETCHAN:
+		if (copy_from_user(&getchan, uarg, sizeof(struct digi_chan)))
+			return -EFAULT;
+
+		port = getchan.ch_port;
+
+		if (port < 0 || port > nd->nd_chan_count)
+			return -EINVAL;
+
+		ch = nd->nd_chan + port;
+
+		getchan.ch_open = (ch->ch_open_count > 0) ? 1 : 0;
+		getchan.ch_txcount = ch->ch_txcount;
+		getchan.ch_rxcount = ch->ch_rxcount;
+		getchan.ch_s_brate = ch->ch_s_brate;
+		getchan.ch_s_estat = ch->ch_s_elast;
+		getchan.ch_s_cflag = ch->ch_s_cflag;
+		getchan.ch_s_iflag = ch->ch_s_iflag;
+		getchan.ch_s_oflag = ch->ch_s_oflag;
+		getchan.ch_s_xflag = ch->ch_s_xflag;
+		getchan.ch_s_mstat = ch->ch_s_mlast;
+
+		if (copy_to_user(uarg, &getchan, sizeof(struct digi_chan)))
+			return -EFAULT;
+		break;
+
+
+	case DIGI_GETNODE:
+		getnode.nd_state = (nd->nd_state & NS_READY) ? 1 : 0;
+		getnode.nd_chan_count = nd->nd_chan_count;
+		getnode.nd_tx_byte = nd->nd_tx_byte;
+		getnode.nd_rx_byte = nd->nd_rx_byte;
+
+		memset(&getnode.nd_ps_desc, 0, MAX_DESC_LEN);
+		strncpy(getnode.nd_ps_desc, nd->nd_ps_desc, MAX_DESC_LEN);
+
+		if (copy_to_user(uarg, &getnode, sizeof(struct digi_node)))
+			return -EFAULT;
+		break;
+
+
+	case DIGI_SETDEBUG:
+		if (copy_from_user(&setdebug, uarg, sizeof(struct digi_debug)))
+			return -EFAULT;
+
+		nd->nd_dpa_debug = setdebug.onoff;
+		nd->nd_dpa_port = setdebug.port;
+		break;
+
+
+	case DIGI_GETVPD:
+		if (nd->nd_vpd_len > 0) {
+			vpd.vpd_len = nd->nd_vpd_len;
+			memcpy(&vpd.vpd_data, &nd->nd_vpd, nd->nd_vpd_len);
+		} else {
+			vpd.vpd_len = 0;
+		}
+
+		if (copy_to_user(uarg, &vpd, sizeof(struct digi_vpd)))
+			return -EFAULT;
+		break;
+	}
+
+	return 0;
+}
+
+/**
+ * dgrp_dpa() -- send data to the device monitor queue
+ * @nd: pointer to a node structure
+ * @buf: buffer of data to copy to the monitoring buffer
+ * @len: number of bytes to transfer to the buffer
+ *
+ * Called by the net device routines to send data to the device
+ * monitor queue.  If the device monitor buffer is too full to
+ * accept the data, it waits until the buffer is ready.
+ */
+static void dgrp_dpa(struct nd_struct *nd, u8 *buf, int nbuf)
+{
+	int n;
+	int r;
+	unsigned long lock_flags;
+
+	/*
+	 *  Grab DPA lock.
+	 */
+	spin_lock_irqsave(&nd->nd_dpa_lock, lock_flags);
+
+	/*
+	 *  Loop while data remains.
+	 */
+	while (nbuf > 0 && nd->nd_dpa_buf != NULL) {
+
+		n = (nd->nd_dpa_out - nd->nd_dpa_in - 1) & DPA_MASK;
+
+		/*
+		 * Enforce flow control on the DPA device.
+		 */
+		if (n < (DPA_MAX - DPA_HIGH_WATER))
+			nd->nd_dpa_flag |= DPA_WAIT_SPACE;
+
+		/*
+		 * This should never happen, as the flow control above
+		 * should have stopped things before they got to this point.
+		 */
+		if (n == 0) {
+			spin_unlock_irqrestore(&nd->nd_dpa_lock, lock_flags);
+			return;
+		}
+
+		/*
+		 * Copy as much data as will fit.
+		 */
+
+		if (n > nbuf)
+			n = nbuf;
+
+		r = DPA_MAX - nd->nd_dpa_in;
+
+		if (r <= n) {
+			memcpy(nd->nd_dpa_buf + nd->nd_dpa_in, buf, r);
+
+			n -= r;
+
+			nd->nd_dpa_in = 0;
+
+			buf += r;
+			nbuf -= r;
+		}
+
+		memcpy(nd->nd_dpa_buf + nd->nd_dpa_in, buf, n);
+
+		nd->nd_dpa_in += n;
+
+		buf += n;
+		nbuf -= n;
+
+		if (nd->nd_dpa_in >= DPA_MAX)
+			pr_info_ratelimited("%s - nd->nd_dpa_in (%i) >= DPA_MAX\n",
+					    __func__, nd->nd_dpa_in);
+
+		/*
+		 *  Wakeup any thread waiting for data
+		 */
+		if (nd->nd_dpa_flag & DPA_WAIT_DATA) {
+			nd->nd_dpa_flag &= ~DPA_WAIT_DATA;
+			wake_up_interruptible(&nd->nd_dpa_wqueue);
+		}
+	}
+
+	/*
+	 *  Release the DPA lock.
+	 */
+	spin_unlock_irqrestore(&nd->nd_dpa_lock, lock_flags);
+}
+
+/**
+ * dgrp_monitor_data() -- builds a DPA data packet
+ * @nd: pointer to a node structure
+ * @type: type of message to be logged in the DPA buffer
+ * @buf: buffer of data to be logged in the DPA buffer
+ * @size -- number of bytes in the "buf" buffer
+ */
+void dgrp_dpa_data(struct nd_struct *nd, int type, u8 *buf, int size)
+{
+	u8 header[5];
+
+	header[0] = type;
+<