drivers/atm/adummy.c

   1 /*
   2  * adummy.c: a dummy ATM driver
   3  */
   4
   5 #include <linux/module.h>
   6 #include <linux/kernel.h>
   7 #include <linux/skbuff.h>
   8 #include <linux/errno.h>
   9 #include <linux/types.h>
  10 #include <linux/string.h>
  11 #include <linux/delay.h>
  12 #include <linux/init.h>
  13 #include <linux/mm.h>
  14 #include <linux/timer.h>
  15 #include <linux/interrupt.h>
  16 #include <asm/io.h>
  17 #include <asm/byteorder.h>
  18 #include <asm/uaccess.h>
  19
  20 #include <linux/atmdev.h>
  21 #include <linux/atm.h>
  22 #include <linux/sonet.h>
  23
  24 /* version definition */
  25
  26 #define DRV_VERSION "1.0"
  27
  28 #define DEV_LABEL "adummy"
  29
  30 #define ADUMMY_DEV(dev) ((struct adummy_dev *) (dev)->dev_data)
  31
  32 struct adummy_dev {
  33         struct atm_dev *atm_dev;
  34
  35         struct list_head entry;
  36 };
  37
  38 /* globals */
  39
  40 static LIST_HEAD(adummy_devs);
  41
  42 static int __init
  43 adummy_start(struct atm_dev *dev)
  44 {
  45         dev->ci_range.vpi_bits = 4;
  46         dev->ci_range.vci_bits = 12;
  47
  48         return 0;
  49 }
  50
  51 static int
  52 adummy_open(struct atm_vcc *vcc)
  53 {
  54         short vpi = vcc->vpi;
  55         int vci = vcc->vci;
  56
  57         if (vci == ATM_VCI_UNSPEC || vpi == ATM_VPI_UNSPEC)
  58                 return 0;
  59
  60         set_bit(ATM_VF_ADDR, &vcc->flags);
  61         set_bit(ATM_VF_READY, &vcc->flags);
  62
  63         return 0;
  64 }
  65
  66 static void
  67 adummy_close(struct atm_vcc *vcc)
  68 {
  69         clear_bit(ATM_VF_READY, &vcc->flags);
  70         clear_bit(ATM_VF_ADDR, &vcc->flags);
  71 }
  72
  73 static int
  74 adummy_send(struct atm_vcc *vcc, struct sk_buff *skb)
  75 {
  76         if (vcc->pop)
  77                 vcc->pop(vcc, skb);
  78         else
  79                 dev_kfree_skb_any(skb);
  80         atomic_inc(&vcc->stats->tx);
  81
  82         return 0;
  83 }
  84
  85 static int
  86 adummy_proc_read(struct atm_dev *dev, loff_t *pos, char *page)
  87 {
  88         int left = *pos;
  89
  90         if (!left--)
  91                 return sprintf(page, "version %s\n", DRV_VERSION);
  92
  93         return 0;
  94 }
  95
  96 static struct atmdev_ops adummy_ops =
  97 {
  98         .open =         adummy_open,
  99         .close =        adummy_close,
 100         .send =         adummy_send,
 101         .proc_read =    adummy_proc_read,
 102         .owner =        THIS_MODULE
 103 };
 104
 105 static int __init adummy_init(void)
 106 {
 107         struct atm_dev *atm_dev;
 108         struct adummy_dev *adummy_dev;
 109         int err = 0;
 110
 111         printk(KERN_ERR "adummy: version %s\n", DRV_VERSION);
 112
 113         adummy_dev = kzalloc(sizeof(struct adummy_dev),
 114                                                    GFP_KERNEL);
 115         if (!adummy_dev) {
 116                 printk(KERN_ERR DEV_LABEL ": kzalloc() failed\n");
 117                 err = -ENOMEM;
 118                 goto out;
 119         }
 120         atm_dev = atm_dev_register(DEV_LABEL, &adummy_ops, -1, NULL);
 121         if (!atm_dev) {
 122                 printk(KERN_ERR DEV_LABEL ": atm_dev_register() failed\n");
 123                 err = -ENODEV;
 124                 goto out_kfree;
 125         }
 126
 127         adummy_dev->atm_dev = atm_dev;
 128         atm_dev->dev_data = adummy_dev;
 129
 130         if (adummy_start(atm_dev)) {
 131                 printk(KERN_ERR DEV_LABEL ": adummy_start() failed\n");
 132                 err = -ENODEV;
 133                 goto out_unregister;
 134         }
 135
 136         list_add(&adummy_dev->entry, &adummy_devs);
 137 out:
 138         return err;
 139
 140 out_unregister:
 141         atm_dev_deregister(atm_dev);
 142 out_kfree:
 143         kfree(adummy_dev);
 144         goto out;
 145 }
 146
 147 static void __exit adummy_cleanup(void)
 148 {
 149         struct adummy_dev *adummy_dev, *next;
 150
 151         list_for_each_entry_safe(adummy_dev, next, &adummy_devs, entry) {
 152                 atm_dev_deregister(adummy_dev->atm_dev);
 153                 kfree(adummy_dev);
 154         }
 155 }
 156
 157 module_init(adummy_init);
 158 module_exit(adummy_cleanup);
 159
 160 MODULE_AUTHOR("chas williams <chas@cmf.nrl.navy.mil>");
 161 MODULE_DESCRIPTION("dummy ATM driver");
 162 MODULE_LICENSE("GPL");