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 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 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 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 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 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 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 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 }; 142 143 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 } 187 188 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