drivers/staging/comedi/proc.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * /proc interface for comedi
   4  *
   5  * COMEDI - Linux Control and Measurement Device Interface
   6  * Copyright (C) 1998 David A. Schleef <ds@schleef.org>
   7  */
   8
   9 /*
  10  * This is some serious bloatware.
  11  *
  12  * Taken from Dave A.'s PCL-711 driver, 'cuz I thought it
  13  * was cool.
  14  */
  15
  16 #include "comedidev.h"
  17 #include "comedi_internal.h"
  18 #include <linux/proc_fs.h>
  19 #include <linux/seq_file.h>
  20
  21 static int comedi_read(struct seq_file *m, void *v)
  22 {
  23         int i;
  24         int devices_q = 0;
  25         struct comedi_driver *driv;
  26
  27         seq_printf(m, "comedi version " COMEDI_RELEASE "\nformat string: %s\n",
  28                    "\"%2d: %-20s %-20s %4d\", i, driver_name, board_name, n_subdevices");
  29
  30         for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
  31                 struct comedi_device *dev = comedi_dev_get_from_minor(i);
  32
  33                 if (!dev)
  34                         continue;
  35
  36                 down_read(&dev->attach_lock);
  37                 if (dev->attached) {
  38                         devices_q = 1;
  39                         seq_printf(m, "%2d: %-20s %-20s %4d\n",
  40                                    i, dev->driver->driver_name,
  41                                    dev->board_name, dev->n_subdevices);
  42                 }
  43                 up_read(&dev->attach_lock);
  44                 comedi_dev_put(dev);
  45         }
  46         if (!devices_q)
  47                 seq_puts(m, "no devices\n");
  48
  49         mutex_lock(&comedi_drivers_list_lock);
  50         for (driv = comedi_drivers; driv; driv = driv->next) {
  51                 seq_printf(m, "%s:\n", driv->driver_name);
  52                 for (i = 0; i < driv->num_names; i++)
  53                         seq_printf(m, " %s\n",
  54                                    *(char **)((char *)driv->board_name +
  55                                               i * driv->offset));
  56
  57                 if (!driv->num_names)
  58                         seq_printf(m, " %s\n", driv->driver_name);
  59         }
  60         mutex_unlock(&comedi_drivers_list_lock);
  61
  62         return 0;
  63 }
  64
  65 /*
  66  * seq_file wrappers for procfile show routines.
  67  */
  68 static int comedi_proc_open(struct inode *inode, struct file *file)
  69 {
  70         return single_open(file, comedi_read, NULL);
  71 }
  72
  73 static const struct file_operations comedi_proc_fops = {
  74         .owner          = THIS_MODULE,
  75         .open           = comedi_proc_open,
  76         .read           = seq_read,
  77         .llseek         = seq_lseek,
  78         .release        = single_release,
  79 };
  80
  81 void __init comedi_proc_init(void)
  82 {
  83         if (!proc_create("comedi", 0444, NULL, &comedi_proc_fops))
  84                 pr_warn("comedi: unable to create proc entry\n");
  85 }
  86
  87 void comedi_proc_cleanup(void)
  88 {
  89         remove_proc_entry("comedi", NULL);
  90 }