drivers/staging/dgrp/dgrp_ports_ops.c

   1 /*
   2  *
   3  * Copyright 1999-2000 Digi International (www.digi.com)
   4  *     James Puzzo <jamesp at digi dot com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2, or (at your option)
   9  * any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
  13  * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  14  * PURPOSE.  See the GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  *
  20  */
  21
  22 /*
  23  *
  24  *  Filename:
  25  *
  26  *     dgrp_ports_ops.c
  27  *
  28  *  Description:
  29  *
  30  *     Handle the file operations required for the /proc/dgrp/ports/...
  31  *     devices.  Basically gathers tty status for the node and returns it.
  32  *
  33  *  Author:
  34  *
  35  *     James A. Puzzo
  36  *
  37  */
  38
  39 #include <linux/module.h>
  40 #include <linux/proc_fs.h>
  41 #include <linux/tty.h>
  42 #include <linux/sched.h>
  43 #include <linux/seq_file.h>
  44
  45 #include "dgrp_common.h"
  46
  47 /* File operation declarations */
  48 static int dgrp_ports_open(struct inode *, struct file *);
  49
  50 const struct file_operations dgrp_ports_ops = {
  51         .owner   = THIS_MODULE,
  52         .open    = dgrp_ports_open,
  53         .read    = seq_read,
  54         .llseek  = seq_lseek,
  55         .release = seq_release
  56 };
  57
  58 static void *dgrp_ports_seq_start(struct seq_file *seq, loff_t *pos)
  59 {
  60         if (*pos == 0)
  61                 seq_puts(seq, "#num tty_open pr_open tot_wait MSTAT  IFLAG  OFLAG  CFLAG  BPS    DIGIFLAGS\n");
  62
  63         return pos;
  64 }
  65
  66 static void *dgrp_ports_seq_next(struct seq_file *seq, void *v, loff_t *pos)
  67 {
  68         struct nd_struct *nd = seq->private;
  69
  70         if (*pos >= nd->nd_chan_count)
  71                 return NULL;
  72
  73         *pos += 1;
  74
  75         return pos;
  76 }
  77
  78 static void dgrp_ports_seq_stop(struct seq_file *seq, void *v)
  79 {
  80 }
  81
  82 static int dgrp_ports_seq_show(struct seq_file *seq, void *v)
  83 {
  84         loff_t *pos = v;
  85         struct nd_struct *nd;
  86         struct ch_struct *ch;
  87         struct un_struct *tun, *pun;
  88         unsigned int totcnt;
  89
  90         nd = seq->private;
  91         if (!nd)
  92                 return 0;
  93
  94         if (*pos >= nd->nd_chan_count)
  95                 return 0;
  96
  97         ch = &nd->nd_chan[*pos];
  98         tun = &ch->ch_tun;
  99         pun = &ch->ch_pun;
 100
 101         /*
 102          * If port is not open and no one is waiting to
 103          * open it, the modem signal values can't be
 104          * trusted, and will be zeroed.
 105          */
 106         totcnt = tun->un_open_count +
 107                 pun->un_open_count +
 108                 ch->ch_wait_count[0] +
 109                 ch->ch_wait_count[1] +
 110                 ch->ch_wait_count[2];
 111
 112         seq_printf(seq, "%02d      %02d      %02d      %02d     0x%04X 0x%04X 0x%04X 0x%04X %-6d 0x%04X\n",
 113                    (int) *pos,
 114                    tun->un_open_count,
 115                    pun->un_open_count,
 116                    ch->ch_wait_count[0] +
 117                    ch->ch_wait_count[1] +
 118                    ch->ch_wait_count[2],
 119                    (totcnt ? ch->ch_s_mlast : 0),
 120                    ch->ch_s_iflag,
 121                    ch->ch_s_oflag,
 122                    ch->ch_s_cflag,
 123                    (ch->ch_s_brate ? (1843200 / ch->ch_s_brate) : 0),
 124                    ch->ch_digi.digi_flags);
 125
 126         return 0;
 127 }
 128
 129 static const struct seq_operations ports_seq_ops = {
 130         .start = dgrp_ports_seq_start,
 131         .next  = dgrp_ports_seq_next,
 132         .stop  = dgrp_ports_seq_stop,
 133         .show  = dgrp_ports_seq_show,
 134 };
 135
 136 /**
 137  * dgrp_ports_open -- open the /proc/dgrp/ports/... device
 138  * @inode: struct inode *
 139  * @file: struct file *
 140  *
 141  * Open function to open the /proc/dgrp/ports device for a PortServer.
 142  * This is the open function for struct file_operations
 143  */
 144 static int dgrp_ports_open(struct inode *inode, struct file *file)
 145 {
 146         struct seq_file *seq;
 147         int rtn;
 148
 149         rtn = seq_open(file, &ports_seq_ops);
 150         if (!rtn) {
 151                 seq = file->private_data;
 152                 seq->private = PDE_DATA(inode);
 153         }
 154
 155         return rtn;
 156 }