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