xref: /linux/drivers/atm/adummy.c (revision 765532c8aaac624b5f8687af6d319c6a1138a257)
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 <linux/slab.h>
17 #include <asm/io.h>
18 #include <asm/byteorder.h>
19 #include <asm/uaccess.h>
20 
21 #include <linux/atmdev.h>
22 #include <linux/atm.h>
23 #include <linux/sonet.h>
24 
25 /* version definition */
26 
27 #define DRV_VERSION "1.0"
28 
29 #define DEV_LABEL "adummy"
30 
31 #define ADUMMY_DEV(dev) ((struct adummy_dev *) (dev)->dev_data)
32 
33 struct adummy_dev {
34 	struct atm_dev *atm_dev;
35 
36 	struct list_head entry;
37 };
38 
39 /* globals */
40 
41 static LIST_HEAD(adummy_devs);
42 
43 static ssize_t __set_signal(struct device *dev,
44 		struct device_attribute *attr,
45 		const char *buf, size_t len)
46 {
47 	struct atm_dev *atm_dev = container_of(dev, struct atm_dev, class_dev);
48 	int signal;
49 
50 	if (sscanf(buf, "%d", &signal) == 1) {
51 
52 		if (signal < ATM_PHY_SIG_LOST || signal > ATM_PHY_SIG_FOUND)
53 			signal = ATM_PHY_SIG_UNKNOWN;
54 
55 		atm_dev_signal_change(atm_dev, signal);
56 		return 1;
57 	}
58 	return -EINVAL;
59 }
60 
61 static ssize_t __show_signal(struct device *dev,
62 	struct device_attribute *attr, char *buf)
63 {
64 	struct atm_dev *atm_dev = container_of(dev, struct atm_dev, class_dev);
65 	return sprintf(buf, "%d\n", atm_dev->signal);
66 }
67 static DEVICE_ATTR(signal, 0644, __show_signal, __set_signal);
68 
69 static struct attribute *adummy_attrs[] = {
70 	&dev_attr_signal.attr,
71 	NULL
72 };
73 
74 static struct attribute_group adummy_group_attrs = {
75 	.name = NULL, /* We want them in dev's root folder */
76 	.attrs = adummy_attrs
77 };
78 
79 static int __init
80 adummy_start(struct atm_dev *dev)
81 {
82 	dev->ci_range.vpi_bits = 4;
83 	dev->ci_range.vci_bits = 12;
84 
85 	return 0;
86 }
87 
88 static int
89 adummy_open(struct atm_vcc *vcc)
90 {
91 	short vpi = vcc->vpi;
92 	int vci = vcc->vci;
93 
94 	if (vci == ATM_VCI_UNSPEC || vpi == ATM_VPI_UNSPEC)
95 		return 0;
96 
97 	set_bit(ATM_VF_ADDR, &vcc->flags);
98 	set_bit(ATM_VF_READY, &vcc->flags);
99 
100 	return 0;
101 }
102 
103 static void
104 adummy_close(struct atm_vcc *vcc)
105 {
106 	clear_bit(ATM_VF_READY, &vcc->flags);
107 	clear_bit(ATM_VF_ADDR, &vcc->flags);
108 }
109 
110 static int
111 adummy_send(struct atm_vcc *vcc, struct sk_buff *skb)
112 {
113 	if (vcc->pop)
114 		vcc->pop(vcc, skb);
115 	else
116 		dev_kfree_skb_any(skb);
117 	atomic_inc(&vcc->stats->tx);
118 
119 	return 0;
120 }
121 
122 static int
123 adummy_proc_read(struct atm_dev *dev, loff_t *pos, char *page)
124 {
125 	int left = *pos;
126 
127 	if (!left--)
128 		return sprintf(page, "version %s\n", DRV_VERSION);
129 
130 	return 0;
131 }
132 
133 static struct atmdev_ops adummy_ops =
134 {
135 	.open =		adummy_open,
136 	.close =	adummy_close,
137 	.send =		adummy_send,
138 	.proc_read =	adummy_proc_read,
139 	.owner =	THIS_MODULE
140 };
141 
142 static int __init adummy_init(void)
143 {
144 	struct atm_dev *atm_dev;
145 	struct adummy_dev *adummy_dev;
146 	int err = 0;
147 
148 	printk(KERN_ERR "adummy: version %s\n", DRV_VERSION);
149 
150 	adummy_dev = kzalloc(sizeof(struct adummy_dev),
151 						   GFP_KERNEL);
152 	if (!adummy_dev) {
153 		printk(KERN_ERR DEV_LABEL ": kzalloc() failed\n");
154 		err = -ENOMEM;
155 		goto out;
156 	}
157 	atm_dev = atm_dev_register(DEV_LABEL, NULL, &adummy_ops, -1, NULL);
158 	if (!atm_dev) {
159 		printk(KERN_ERR DEV_LABEL ": atm_dev_register() failed\n");
160 		err = -ENODEV;
161 		goto out_kfree;
162 	}
163 
164 	adummy_dev->atm_dev = atm_dev;
165 	atm_dev->dev_data = adummy_dev;
166 
167 	if (sysfs_create_group(&atm_dev->class_dev.kobj, &adummy_group_attrs))
168 		dev_err(&atm_dev->class_dev, "Could not register attrs for adummy\n");
169 
170 	if (adummy_start(atm_dev)) {
171 		printk(KERN_ERR DEV_LABEL ": adummy_start() failed\n");
172 		err = -ENODEV;
173 		goto out_unregister;
174 	}
175 
176 	list_add(&adummy_dev->entry, &adummy_devs);
177 out:
178 	return err;
179 
180 out_unregister:
181 	atm_dev_deregister(atm_dev);
182 out_kfree:
183 	kfree(adummy_dev);
184 	goto out;
185 }
186 
187 static void __exit adummy_cleanup(void)
188 {
189 	struct adummy_dev *adummy_dev, *next;
190 
191 	list_for_each_entry_safe(adummy_dev, next, &adummy_devs, entry) {
192 		atm_dev_deregister(adummy_dev->atm_dev);
193 		kfree(adummy_dev);
194 	}
195 }
196 
197 module_init(adummy_init);
198 module_exit(adummy_cleanup);
199 
200 MODULE_AUTHOR("chas williams <chas@cmf.nrl.navy.mil>");
201 MODULE_DESCRIPTION("dummy ATM driver");
202 MODULE_LICENSE("GPL");
203