1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * adummy.c: a dummy ATM driver
4 */
5
6 #include <linux/module.h>
7 #include <linux/kernel.h>
8 #include <linux/skbuff.h>
9 #include <linux/errno.h>
10 #include <linux/types.h>
11 #include <linux/string.h>
12 #include <linux/delay.h>
13 #include <linux/init.h>
14 #include <linux/mm.h>
15 #include <linux/timer.h>
16 #include <linux/interrupt.h>
17 #include <linux/slab.h>
18 #include <asm/io.h>
19 #include <asm/byteorder.h>
20 #include <linux/uaccess.h>
21
22 #include <linux/atmdev.h>
23 #include <linux/atm.h>
24 #include <linux/sonet.h>
25
26 /* version definition */
27
28 #define DRV_VERSION "1.0"
29
30 #define DEV_LABEL "adummy"
31
32 #define ADUMMY_DEV(dev) ((struct adummy_dev *) (dev)->dev_data)
33
34 struct adummy_dev {
35 struct atm_dev *atm_dev;
36
37 struct list_head entry;
38 };
39
40 /* globals */
41
42 static LIST_HEAD(adummy_devs);
43
__set_signal(struct device * dev,struct device_attribute * attr,const char * buf,size_t len)44 static ssize_t __set_signal(struct device *dev,
45 struct device_attribute *attr,
46 const char *buf, size_t len)
47 {
48 struct atm_dev *atm_dev = container_of(dev, struct atm_dev, class_dev);
49 int signal;
50
51 if (sscanf(buf, "%d", &signal) == 1) {
52
53 if (signal < ATM_PHY_SIG_LOST || signal > ATM_PHY_SIG_FOUND)
54 signal = ATM_PHY_SIG_UNKNOWN;
55
56 atm_dev_signal_change(atm_dev, signal);
57 return 1;
58 }
59 return -EINVAL;
60 }
61
__show_signal(struct device * dev,struct device_attribute * attr,char * buf)62 static ssize_t __show_signal(struct device *dev,
63 struct device_attribute *attr, char *buf)
64 {
65 struct atm_dev *atm_dev = container_of(dev, struct atm_dev, class_dev);
66 return sprintf(buf, "%d\n", atm_dev->signal);
67 }
68 static DEVICE_ATTR(signal, 0644, __show_signal, __set_signal);
69
70 static struct attribute *adummy_attrs[] = {
71 &dev_attr_signal.attr,
72 NULL
73 };
74
75 static const struct attribute_group adummy_group_attrs = {
76 .name = NULL, /* We want them in dev's root folder */
77 .attrs = adummy_attrs
78 };
79
80 static int __init
adummy_start(struct atm_dev * dev)81 adummy_start(struct atm_dev *dev)
82 {
83 dev->ci_range.vpi_bits = 4;
84 dev->ci_range.vci_bits = 12;
85
86 return 0;
87 }
88
89 static int
adummy_open(struct atm_vcc * vcc)90 adummy_open(struct atm_vcc *vcc)
91 {
92 short vpi = vcc->vpi;
93 int vci = vcc->vci;
94
95 if (vci == ATM_VCI_UNSPEC || vpi == ATM_VPI_UNSPEC)
96 return 0;
97
98 set_bit(ATM_VF_ADDR, &vcc->flags);
99 set_bit(ATM_VF_READY, &vcc->flags);
100
101 return 0;
102 }
103
104 static void
adummy_close(struct atm_vcc * vcc)105 adummy_close(struct atm_vcc *vcc)
106 {
107 clear_bit(ATM_VF_READY, &vcc->flags);
108 clear_bit(ATM_VF_ADDR, &vcc->flags);
109 }
110
111 static int
adummy_send(struct atm_vcc * vcc,struct sk_buff * skb)112 adummy_send(struct atm_vcc *vcc, struct sk_buff *skb)
113 {
114 if (vcc->pop)
115 vcc->pop(vcc, skb);
116 else
117 dev_kfree_skb_any(skb);
118 atomic_inc(&vcc->stats->tx);
119
120 return 0;
121 }
122
123 static int
adummy_proc_read(struct atm_dev * dev,loff_t * pos,char * page)124 adummy_proc_read(struct atm_dev *dev, loff_t *pos, char *page)
125 {
126 int left = *pos;
127
128 if (!left--)
129 return sprintf(page, "version %s\n", DRV_VERSION);
130
131 return 0;
132 }
133
134 static const struct atmdev_ops adummy_ops =
135 {
136 .open = adummy_open,
137 .close = adummy_close,
138 .send = adummy_send,
139 .proc_read = adummy_proc_read,
140 .owner = THIS_MODULE
141 };
142
adummy_init(void)143 static int __init adummy_init(void)
144 {
145 struct atm_dev *atm_dev;
146 struct adummy_dev *adummy_dev;
147 int err = 0;
148
149 printk(KERN_ERR "adummy: version %s\n", DRV_VERSION);
150
151 adummy_dev = kzalloc(sizeof(struct adummy_dev),
152 GFP_KERNEL);
153 if (!adummy_dev) {
154 printk(KERN_ERR DEV_LABEL ": kzalloc() failed\n");
155 err = -ENOMEM;
156 goto out;
157 }
158 atm_dev = atm_dev_register(DEV_LABEL, NULL, &adummy_ops, -1, NULL);
159 if (!atm_dev) {
160 printk(KERN_ERR DEV_LABEL ": atm_dev_register() failed\n");
161 err = -ENODEV;
162 goto out_kfree;
163 }
164
165 adummy_dev->atm_dev = atm_dev;
166 atm_dev->dev_data = adummy_dev;
167
168 if (sysfs_create_group(&atm_dev->class_dev.kobj, &adummy_group_attrs))
169 dev_err(&atm_dev->class_dev, "Could not register attrs for adummy\n");
170
171 if (adummy_start(atm_dev)) {
172 printk(KERN_ERR DEV_LABEL ": adummy_start() failed\n");
173 err = -ENODEV;
174 goto out_unregister;
175 }
176
177 list_add(&adummy_dev->entry, &adummy_devs);
178 out:
179 return err;
180
181 out_unregister:
182 atm_dev_deregister(atm_dev);
183 out_kfree:
184 kfree(adummy_dev);
185 goto out;
186 }
187
adummy_cleanup(void)188 static void __exit adummy_cleanup(void)
189 {
190 struct adummy_dev *adummy_dev, *next;
191
192 list_for_each_entry_safe(adummy_dev, next, &adummy_devs, entry) {
193 atm_dev_deregister(adummy_dev->atm_dev);
194 kfree(adummy_dev);
195 }
196 }
197
198 module_init(adummy_init);
199 module_exit(adummy_cleanup);
200
201 MODULE_AUTHOR("chas williams <chas@cmf.nrl.navy.mil>");
202 MODULE_DESCRIPTION("dummy ATM driver");
203 MODULE_LICENSE("GPL");
204