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.tgzSigned-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/dgrp/Kconfig

+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.

drivers/staging/dgrp/Makefile

+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

drivers/staging/dgrp/README

+The user space code to work with this driver is located at
+https://github.com/wfp5p/dgrp-utils

drivers/staging/dgrp/TODO

+- Use configfs for config stuff.  This will require changes to the
+  user space code.
+
+- Check the calls to tty_register_device.  In particular, check to see
+  if there should be some handling for IS_ERR(classp).
+
+- dgrp_send() and dgrp_receive() could use some refactoring

drivers/staging/dgrp/dgrp_common.c

+/*
+ *
+ * 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);
+}

drivers/staging/dgrp/dgrp_common.h

+/*
+ *
+ * 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 */

drivers/staging/dgrp/dgrp_driver.c

+/*
+ *
+ * Copyright 1999-2003 Digi International (www.digi.com)
+ *     Jeff Randall
+ *     James Puzzo  <jamesp at digi dot com>
+ *     Scott Kilau  <Scott_Kilau 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.
+ *
+ */
+
+/*
+ *	Driver specific includes
+ */
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <linux/init.h>
+
+/*
+ *  PortServer includes
+ */
+#include "dgrp_common.h"
+
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Digi International, http://www.digi.com");
+MODULE_DESCRIPTION("RealPort driver for Digi's ethernet-based serial connectivity product line");
+MODULE_VERSION(DIGI_VERSION);
+
+struct list_head nd_struct_list;
+struct dgrp_poll_data dgrp_poll_data;
+
+int dgrp_rawreadok = 1;		/* Bypass flipbuf on input */
+int dgrp_register_cudevices = 1;/* Turn on/off registering legacy cu devices */
+int dgrp_register_prdevices = 1;/* Turn on/off registering transparent print */
+int dgrp_poll_tick = 20;	/* Poll interval - in ms */
+
+module_param_named(rawreadok, dgrp_rawreadok, int, 0644);
+MODULE_PARM_DESC(rawreadok, "Bypass flip buffers on input");
+
+module_param_named(register_cudevices, dgrp_register_cudevices, int, 0644);
+MODULE_PARM_DESC(register_cudevices, "Turn on/off registering legacy cu devices");
+
+module_param_named(register_prdevices, dgrp_register_prdevices, int, 0644);
+MODULE_PARM_DESC(register_prdevices, "Turn on/off registering transparent print devices");
+
+module_param_named(pollrate, dgrp_poll_tick, int, 0644);
+MODULE_PARM_DESC(pollrate, "Poll interval in ms");
+
+/* Driver load/unload functions */
+static int dgrp_init_module(void);
+static void dgrp_cleanup_module(void);
+
+module_init(dgrp_init_module);
+module_exit(dgrp_cleanup_module);
+
+/*
+ * init_module()
+ *
+ * Module load.  This is where it all starts.
+ */
+static int dgrp_init_module(void)
+{
+	INIT_LIST_HEAD(&nd_struct_list);
+
+	spin_lock_init(&dgrp_poll_data.poll_lock);
+	init_timer(&dgrp_poll_data.timer);
+	dgrp_poll_data.poll_tick = dgrp_poll_tick;
+	dgrp_poll_data.timer.function = dgrp_poll_handler;
+	dgrp_poll_data.timer.data = (unsigned long) &dgrp_poll_data;
+
+	dgrp_create_class_sysfs_files();
+
+	dgrp_register_proc();
+
+	return 0;
+}
+
+
+/*
+ *	Module unload.  This is where it all ends.
+ */
+static void dgrp_cleanup_module(void)
+{
+	struct nd_struct *nd, *next;
+
+	/*
+	 *	Attempting to free resources in backwards
+	 *	order of allocation, in case that helps
+	 *	memory pool fragmentation.
+	 */
+	dgrp_unregister_proc();
+
+	dgrp_remove_class_sysfs_files();
+
+
+	list_for_each_entry_safe(nd, next, &nd_struct_list, list) {
+		dgrp_tty_uninit(nd);
+		kfree(nd);
+	}
+}

drivers/staging/dgrp/dgrp_mon_ops.c

+/*****************************************************************************
+ *
+ * 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_mon_ops.c
+ *
+ *  Description:
+ *
+ *     Handle the file operations required for the "monitor" devices.
+ *     Includes those functions required to register the "mon" devices
+ *     in "/proc".
+ *
+ *  Author:
+ *
+ *     James A. Puzzo
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/sched.h>
+#include <asm/unaligned.h>
+#include <linux/proc_fs.h>
+
+#include "dgrp_common.h"
+
+/* File operation declarations */
+static int dgrp_mon_open(struct inode *, struct file *);
+static int dgrp_mon_release(struct inode *, struct file *);
+static ssize_t dgrp_mon_read(struct file *, char __user *, size_t, loff_t *);
+static long dgrp_mon_ioctl(struct file *file, unsigned int cmd,
+			   unsigned long arg);
+
+static const struct file_operations mon_ops = {
+	.owner   = THIS_MODULE,
+	.read    = dgrp_mon_read,
+	.unlocked_ioctl = dgrp_mon_ioctl,
+	.open    = dgrp_mon_open,
+	.release = dgrp_mon_release,
+};
+
+static struct inode_operations mon_inode_ops = {
+	.permission = dgrp_inode_permission
+};
+
+void dgrp_register_mon_hook(struct proc_dir_entry *de)
+{
+	struct nd_struct *node = de->data;
+
+	de->proc_iops = &mon_inode_ops;
+	de->proc_fops = &mon_ops;
+	node->nd_mon_de = de;
+	sema_init(&node->nd_mon_semaphore, 1);
+}
+
+/**
+ * dgrp_mon_open() -- open /proc/dgrp/ports device for a PortServer
+ * @inode: struct inode *
+ * @file: struct file *
+ *
+ * Open function to open the /proc/dgrp/ports device for a PortServer.
+ */
+static int dgrp_mon_open(struct inode *inode, struct file *file)
+{
+	struct nd_struct *nd;
+	struct proc_dir_entry *de;
+	struct timeval tv;
+	uint32_t time;
+	u8 *buf;
+	int rtn;
+
+	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 monitor buffer.
+	 */
+
+	/*
+	 *  Grab the MON lock.
+	 */
+	down(&nd->nd_mon_semaphore);
+
+	if (nd->nd_mon_buf) {
+		rtn = -EBUSY;
+		goto done_up;
+	}
+
+	nd->nd_mon_buf = kmalloc(MON_MAX, GFP_KERNEL);
+
+	if (!nd->nd_mon_buf) {
+		rtn = -ENOMEM;
+		goto done_up;
+	}
+
+	/*
+	 *  Enter an RPDUMP file header into the buffer.
+	 */
+
+	buf = nd->nd_mon_buf;
+
+	strcpy(buf, RPDUMP_MAGIC);
+	buf += strlen(buf) + 1;
+
+	do_gettimeofday(&tv);
+
+	/*
+	 *  tv.tv_sec might be a 64 bit quantity.  Pare
+	 *  it down to 32 bits before attempting to encode
+	 *  it.
+	 */
+	time = (uint32_t) (tv.tv_sec & 0xffffffff);
+
+	put_unaligned_be32(time, buf);
+	put_unaligned_be16(0, buf + 4);
+	buf += 6;
+
+	if (nd->nd_tx_module) {
+		buf[0] = RPDUMP_CLIENT;
+		put_unaligned_be32(0, buf + 1);
+		put_unaligned_be16(1, buf + 5);
+		buf[7] = 0xf0 + nd->nd_tx_module;
+		buf += 8;
+	}
+
+	if (nd->nd_rx_module) {
+		buf[0] = RPDUMP_SERVER;
+		put_unaligned_be32(0, buf + 1);
+		put_unaligned_be16(1, buf + 5);
+		buf[7] = 0xf0 + nd->nd_rx_module;
+		buf += 8;
+	}
+
+	nd->nd_mon_out = 0;
+	nd->nd_mon_in  = buf - nd->nd_mon_buf;
+	nd->nd_mon_lbolt = jiffies;
+
+done_up:
+	up(&nd->nd_mon_semaphore);
+
+done:
+	if (rtn)
+		module_put(THIS_MODULE);
+	return rtn;
+}
+
+
+/**
+ * dgrp_mon_release() - Close the MON device for a particular PortServer
+ * @inode: struct inode *
+ * @file: struct file *
+ */
+static int dgrp_mon_release(struct inode *inode, struct file *file)
+{
+	struct nd_struct *nd;
+
+	/*
+	 *  Get the node pointer, and quit if it doesn't exist.
+	 */
+	nd = (struct nd_struct *)(file->private_data);
+	if (!nd)
+		goto done;
+
+	/*
+	 *  Free the monitor buffer.
+	 */
+
+	down(&nd->nd_mon_semaphore);
+
+	kfree(nd->nd_mon_buf);
+	nd->nd_mon_buf = NULL;
+	nd->nd_mon_out = nd->nd_mon_in;
+
+	/*
+	 *  Wakeup any thread waiting for buffer space.
+	 */
+
+	if (nd->nd_mon_flag & MON_WAIT_SPACE) {
+		nd->nd_mon_flag &= ~MON_WAIT_SPACE;
+		wake_up_interruptible(&nd->nd_mon_wqueue);
+	}
+
+	up(&nd->nd_mon_semaphore);
+
+	/*
+	 *  Make sure there is no thread in the middle of writing a packet.
+	 */
+	down(&nd->nd_net_semaphore);
+	up(&nd->nd_net_semaphore);
+
+done:
+	module_put(THIS_MODULE);
+	file->private_data = NULL;
+	return 0;
+}
+
+/**
+ * dgrp_mon_read() -- Copy data from the monitoring buffer to the user
+ */
+static ssize_t dgrp_mon_read(struct file *file, char __user *buf, size_t count,
+			     loff_t *ppos)
+{
+	struct nd_struct *nd;
+	int r;
+	int offset = 0;
+	int res = 0;
+	ssize_t rtn;
+
+	/*
+	 *  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.
+	 */
+
+	down(&nd->nd_mon_semaphore);
+
+	for (;;) {
+		res = (nd->nd_mon_in - nd->nd_mon_out) & MON_MASK;
+
+		if (res)
+			break;
+
+		nd->nd_mon_flag |= MON_WAIT_DATA;
+
+		up(&nd->nd_mon_semaphore);
+
+		/*
+		 * Go to sleep waiting until the condition becomes true.
+		 */
+		rtn = wait_event_interruptible(nd->nd_mon_wqueue,
+					       ((nd->nd_mon_flag & MON_WAIT_DATA) == 0));
+
+		if (rtn)
+			return rtn;
+
+		down(&nd->nd_mon_semaphore);
+	}
+
+	/*
+	 *  Read whatever is there.
+	 */
+
+	if (res > count)
+		res = count;
+
+	r = MON_MAX - nd->nd_mon_out;
+
+	if (r <= res) {
+		rtn = copy_to_user((void __user *)buf,
+				   nd->nd_mon_buf + nd->nd_mon_out, r);
+		if (rtn) {
+			up(&nd->nd_mon_semaphore);
+			return -EFAULT;
+		}
+
+		nd->nd_mon_out = 0;
+		res -= r;
+		offset = r;
+	}
+
+	rtn = copy_to_user((void __user *) buf + offset,
+			   nd->nd_mon_buf + nd->nd_mon_out, res);
+	if (rtn) {
+		up(&nd->nd_mon_semaphore);
+		return -EFAULT;
+	}
+
+	nd->nd_mon_out += res;
+
+	*ppos += res;
+
+	up(&nd->nd_mon_semaphore);
+
+	/*
+	 *  Wakeup any thread waiting for buffer space.
+	 */
+
+	if (nd->nd_mon_flag & MON_WAIT_SPACE) {
+		nd->nd_mon_flag &= ~MON_WAIT_SPACE;
+		wake_up_interruptible(&nd->nd_mon_wqueue);
+	}
+
+	return res;
+}
+
+/*  ioctl is not valid on monitor device */
+static long dgrp_mon_ioctl(struct file *file, unsigned int cmd,
+			   unsigned long arg)
+{
+	return -EINVAL;
+}

drivers/staging/dgrp/dgrp_ports_ops.c

+/*
+ *
+ * Copyright 1999-2000 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+/*
+ *
+ *  Filename:
+ *
+ *     dgrp_ports_ops.c
+ *
+ *  Description:
+ *
+ *     Handle the file operations required for the /proc/dgrp/ports/...
+ *     devices.  Basically gathers tty status for the node and returns it.
+ *
+ *  Author:
+ *
+ *     James A. Puzzo
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/tty.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+
+#include "dgrp_common.h"
+
+/* File operation declarations */
+static int dgrp_ports_open(struct inode *, struct file *);
+
+static const struct file_operations ports_ops = {
+	.owner   = THIS_MODULE,
+	.open    = dgrp_ports_open,
+	.read    = seq_read,
+	.llseek	 = seq_lseek,
+	.release = seq_release
+};
+
+static struct inode_operations ports_inode_ops = {
+	.permission = dgrp_inode_permission
+};
+
+
+void dgrp_register_ports_hook(struct proc_dir_entry *de)
+{
+	struct nd_struct *node = de->data;
+
+	de->proc_iops = &ports_inode_ops;
+	de->proc_fops = &ports_ops;
+	node->nd_ports_de = de;
+}
+
+static void *dgrp_ports_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	if (*pos == 0)
+		seq_puts(seq, "#num tty_open pr_open tot_wait MSTAT  IFLAG  OFLAG  CFLAG  BPS    DIGIFLAGS\n");
+
+	return pos;
+}
+
+static void *dgrp_ports_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct nd_struct *nd = seq->private;
+
+	if (*pos >= nd->nd_chan_count)
+		return NULL;
+
+	*pos += 1;
+
+	return pos;
+}
+
+static void dgrp_ports_seq_stop(struct seq_file *seq, void *v)
+{
+}
+
+static int dgrp_ports_seq_show(struct seq_file *seq, void *v)
+{
+	loff_t *pos = v;
+	struct nd_struct *nd;
+	struct ch_struct *ch;
+	struct un_struct *tun, *pun;
+	unsigned int totcnt;
+
+	nd = seq->private;
+	if (!nd)
+		return 0;
+
+	if (*pos >= nd->nd_chan_count)
+		return 0;
+
+	ch = &nd->nd_chan[*pos];
+	tun = &ch->ch_tun;
+	pun = &ch->ch_pun;
+
+	/*
+	 * If port is not open and no one is waiting to
+	 * open it, the modem signal values can't be
+	 * trusted, and will be zeroed.
+	 */
+	totcnt = tun->un_open_count +
+		pun->un_open_count +
+		ch->ch_wait_count[0] +
+		ch->ch_wait_count[1] +
+		ch->ch_wait_count[2];
+
+	seq_printf(seq, "%02d      %02d      %02d      %02d     0x%04X 0x%04X 0x%04X 0x%04X %-6d 0x%04X\n",
+		   (int) *pos,
+		   tun->un_open_count,
+		   pun->un_open_count,
+		   ch->ch_wait_count[0] +
+		   ch->ch_wait_count[1] +
+		   ch->ch_wait_count[2],
+		   (totcnt ? ch->ch_s_mlast : 0),
+		   ch->ch_s_iflag,
+		   ch->ch_s_oflag,
+		   ch->ch_s_cflag,
+		   (ch->ch_s_brate ? (1843200 / ch->ch_s_brate) : 0),
+		   ch->ch_digi.digi_flags);
+
+	return 0;
+}
+
+static const struct seq_operations ports_seq_ops = {
+	.start = dgrp_ports_seq_start,
+	.next  = dgrp_ports_seq_next,
+	.stop  = dgrp_ports_seq_stop,
+	.show  = dgrp_ports_seq_show,
+};
+
+/**
+ * dgrp_ports_open -- open the /proc/dgrp/ports/... device
+ * @inode: struct inode *
+ * @file: struct file *
+ *
+ * Open function to open the /proc/dgrp/ports device for a PortServer.
+ * This is the open function for struct file_operations
+ */
+static int dgrp_ports_open(struct inode *inode, struct file *file)
+{
+	struct seq_file *seq;
+	int rtn;
+
+	rtn = seq_open(file, &ports_seq_ops);
+	if (!rtn) {
+		seq = file->private_data;
+		seq->private = PDE(inode)->data;
+	}
+
+	return rtn;
+}

drivers/staging/dgrp/digirp.h

+/************************************************************************
+ * HP-UX Realport Daemon interface file.
+ *
+ * Copyright (C) 1998, by Digi International.  All Rights Reserved.
+ ************************************************************************/
+
+#ifndef _DIGIDRP_H
+#define _DIGIDRP_H
+
+/************************************************************************
+ * This file contains defines for the ioctl() interface to
+ * the realport driver.   This ioctl() interface is used by the
+ * daemon to set speed setup parameters honored by the driver.
+ ************************************************************************/
+
+struct link_struct {
+	int lk_fast_rate;  /* Fast line rate to be used
+			      when the delay is less-equal
+			      to lk_fast_delay */
+
+	int lk_fast_delay; /* Fast line rate delay in
+			      milliseconds */
+
+	int lk_slow_rate;  /* Slow line rate to be used when
+			      the delay is greater-equal
+			      to lk_slow_delay */
+
+	int lk_slow_delay; /* Slow line rate delay in
+			      milliseconds */
+
+	int lk_header_size; /* Estimated packet header size
+			       when sent across the slowest
+			       link.  */
+};
+
+#define DIGI_GETLINK	_IOW('e', 103, struct link_struct)	/* Get link parameters */
+#define DIGI_SETLINK	_IOW('e', 104, struct link_struct)	/* Set link parameters */
+
+
+/************************************************************************
+ * This module provides application access to special Digi
+ * serial line enhancements which are not standard UNIX(tm) features.
+ ************************************************************************/
+
+struct	digiflow_struct {
+	unsigned char	startc;				/* flow cntl start char	*/
+	unsigned char	stopc;				/* flow cntl stop char	*/
+};
+
+/************************************************************************
+ * Values for digi_flags
+ ************************************************************************/
+#define DIGI_IXON	0x0001		/* Handle IXON in the FEP	*/
+#define DIGI_FAST	0x0002		/* Fast baud rates		*/
+#define RTSPACE		0x0004		/* RTS input flow control	*/
+#define CTSPACE		0x0008		/* CTS output flow control	*/
+#define DSRPACE		0x0010		/* DSR output flow control	*/
+#define DCDPACE		0x0020		/* DCD output flow control	*/
+#define DTRPACE		0x0040		/* DTR input flow control	*/
+#define DIGI_COOK	0x0080		/* Cooked processing done in FEP */
+#define DIGI_FORCEDCD	0x0100		/* Force carrier		*/
+#define	DIGI_ALTPIN	0x0200		/* Alternate RJ-45 pin config	*/
+#define	DIGI_AIXON	0x0400		/* Aux flow control in fep	*/
+#define	DIGI_PRINTER	0x0800		/* Hold port open for flow cntrl */
+#define DIGI_PP_INPUT	0x1000		/* Change parallel port to input */
+#define DIGI_422	0x4000		/* Change parallel port to input */
+#define DIGI_RTS_TOGGLE	0x8000		/* Support RTS Toggle		 */
+
+
+/************************************************************************
+ * Values associated with transparent print
+ ************************************************************************/
+#define DIGI_PLEN	8		/* String length */
+#define	DIGI_TSIZ	10		/* Terminal string len */
+
+
+/************************************************************************
+ * Structure used with ioctl commands for DIGI parameters.
+ ************************************************************************/
+struct digi_struct {
+	unsigned short	digi_flags;		/* Flags (see above)	*/
+	unsigned short	digi_maxcps;		/* Max printer CPS	*/
+	unsigned short	digi_maxchar;		/* Max chars in print queue */
+	unsigned short	digi_bufsize;		/* Buffer size		*/
+	unsigned char	digi_onlen;		/* Length of ON string	*/
+	unsigned char	digi_offlen;		/* Length of OFF string	*/
+	char		digi_onstr[DIGI_PLEN];	/* Printer on string	*/
+	char		digi_offstr[DIGI_PLEN];	/* Printer off string	*/
+	char		digi_term[DIGI_TSIZ];	/* terminal string	*/
+};
+
+/************************************************************************
+ * Ioctl command arguments for DIGI parameters.
+ ************************************************************************/
+/* Read params */
+#define DIGI_GETA	_IOR('e', 94, struct digi_struct)
+
+/* Set params */
+#define DIGI_SETA	_IOW('e', 95, struct digi_struct)
+
+/* Drain & set params	*/
+#define DIGI_SETAW	_IOW('e', 96, struct digi_struct)
+
+/* Drain, flush & set params */
+#define DIGI_SETAF	_IOW('e', 97, struct digi_struct)
+
+/* Get startc/stopc flow control characters */
+#define	DIGI_GETFLOW	_IOR('e', 99, struct digiflow_struct)
+
+/* Set startc/stopc flow control characters */
+#define	DIGI_SETFLOW	_IOW('e', 100, struct digiflow_struct)
+
+/* Get Aux. startc/stopc flow control chars */
+#define	DIGI_GETAFLOW	_IOR('e', 101, struct digiflow_struct)
+
+/* Set Aux. startc/stopc flow control chars */
+#define	DIGI_SETAFLOW	_IOW('e', 102, struct digiflow_struct)
+
+/* Set integer baud rate */
+#define	DIGI_SETCUSTOMBAUD	_IOW('e', 106, int)
+
+/* Get integer baud rate */
+#define	DIGI_GETCUSTOMBAUD	_IOR('e', 107, int)
+
+#define	DIGI_GEDELAY	_IOR('d', 246, int)	/* Get edelay */
+#define	DIGI_SEDELAY	_IOW('d', 247, int)	/* Get edelay */
+
+
+#endif /* _DIGIDRP_H */