1 /* 2 * Copyright IBM Corp. 2004 3 * 4 * Tape class device support 5 * 6 * Author: Stefan Bader <shbader@de.ibm.com> 7 * Based on simple class device code by Greg K-H 8 */ 9 10 #define KMSG_COMPONENT "tape" 11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 12 13 #include <linux/slab.h> 14 15 #include "tape_class.h" 16 17 MODULE_AUTHOR("Stefan Bader <shbader@de.ibm.com>"); 18 MODULE_DESCRIPTION( 19 "Copyright IBM Corp. 2004 All Rights Reserved.\n" 20 "tape_class.c" 21 ); 22 MODULE_LICENSE("GPL"); 23 24 static struct class *tape_class; 25 26 /* 27 * Register a tape device and return a pointer to the cdev structure. 28 * 29 * device 30 * The pointer to the struct device of the physical (base) device. 31 * drivername 32 * The pointer to the drivers name for it's character devices. 33 * dev 34 * The intended major/minor number. The major number may be 0 to 35 * get a dynamic major number. 36 * fops 37 * The pointer to the drivers file operations for the tape device. 38 * devname 39 * The pointer to the name of the character device. 40 */ 41 struct tape_class_device *register_tape_dev( 42 struct device * device, 43 dev_t dev, 44 const struct file_operations *fops, 45 char * device_name, 46 char * mode_name) 47 { 48 struct tape_class_device * tcd; 49 int rc; 50 char * s; 51 52 tcd = kzalloc(sizeof(struct tape_class_device), GFP_KERNEL); 53 if (!tcd) 54 return ERR_PTR(-ENOMEM); 55 56 strncpy(tcd->device_name, device_name, TAPECLASS_NAME_LEN); 57 for (s = strchr(tcd->device_name, '/'); s; s = strchr(s, '/')) 58 *s = '!'; 59 strncpy(tcd->mode_name, mode_name, TAPECLASS_NAME_LEN); 60 for (s = strchr(tcd->mode_name, '/'); s; s = strchr(s, '/')) 61 *s = '!'; 62 63 tcd->char_device = cdev_alloc(); 64 if (!tcd->char_device) { 65 rc = -ENOMEM; 66 goto fail_with_tcd; 67 } 68 69 tcd->char_device->owner = fops->owner; 70 tcd->char_device->ops = fops; 71 tcd->char_device->dev = dev; 72 73 rc = cdev_add(tcd->char_device, tcd->char_device->dev, 1); 74 if (rc) 75 goto fail_with_cdev; 76 77 tcd->class_device = device_create(tape_class, device, 78 tcd->char_device->dev, NULL, 79 "%s", tcd->device_name); 80 rc = PTR_RET(tcd->class_device); 81 if (rc) 82 goto fail_with_cdev; 83 rc = sysfs_create_link( 84 &device->kobj, 85 &tcd->class_device->kobj, 86 tcd->mode_name 87 ); 88 if (rc) 89 goto fail_with_class_device; 90 91 return tcd; 92 93 fail_with_class_device: 94 device_destroy(tape_class, tcd->char_device->dev); 95 96 fail_with_cdev: 97 cdev_del(tcd->char_device); 98 99 fail_with_tcd: 100 kfree(tcd); 101 102 return ERR_PTR(rc); 103 } 104 EXPORT_SYMBOL(register_tape_dev); 105 106 void unregister_tape_dev(struct device *device, struct tape_class_device *tcd) 107 { 108 if (tcd != NULL && !IS_ERR(tcd)) { 109 sysfs_remove_link(&device->kobj, tcd->mode_name); 110 device_destroy(tape_class, tcd->char_device->dev); 111 cdev_del(tcd->char_device); 112 kfree(tcd); 113 } 114 } 115 EXPORT_SYMBOL(unregister_tape_dev); 116 117 118 static int __init tape_init(void) 119 { 120 tape_class = class_create(THIS_MODULE, "tape390"); 121 122 return 0; 123 } 124 125 static void __exit tape_exit(void) 126 { 127 class_destroy(tape_class); 128 tape_class = NULL; 129 } 130 131 postcore_initcall(tape_init); 132 module_exit(tape_exit); 133