1 /* 2 * (C) Copyright IBM Corp. 2004 3 * tape_class.c ($Revision: 1.8 $) 4 * 5 * Tape class device support 6 * 7 * Author: Stefan Bader <shbader@de.ibm.com> 8 * Based on simple class device code by Greg K-H 9 */ 10 #include "tape_class.h" 11 12 MODULE_AUTHOR("Stefan Bader <shbader@de.ibm.com>"); 13 MODULE_DESCRIPTION( 14 "(C) Copyright IBM Corp. 2004 All Rights Reserved.\n" 15 "tape_class.c ($Revision: 1.8 $)" 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 = kmalloc(sizeof(struct tape_class_device), GFP_KERNEL); 48 if (!tcd) 49 return ERR_PTR(-ENOMEM); 50 51 memset(tcd, 0, sizeof(struct tape_class_device)); 52 strncpy(tcd->device_name, device_name, TAPECLASS_NAME_LEN); 53 for (s = strchr(tcd->device_name, '/'); s; s = strchr(s, '/')) 54 *s = '!'; 55 strncpy(tcd->mode_name, mode_name, TAPECLASS_NAME_LEN); 56 for (s = strchr(tcd->mode_name, '/'); s; s = strchr(s, '/')) 57 *s = '!'; 58 59 tcd->char_device = cdev_alloc(); 60 if (!tcd->char_device) { 61 rc = -ENOMEM; 62 goto fail_with_tcd; 63 } 64 65 tcd->char_device->owner = fops->owner; 66 tcd->char_device->ops = fops; 67 tcd->char_device->dev = dev; 68 69 rc = cdev_add(tcd->char_device, tcd->char_device->dev, 1); 70 if (rc) 71 goto fail_with_cdev; 72 73 tcd->class_device = class_device_create( 74 tape_class, 75 NULL, 76 tcd->char_device->dev, 77 device, 78 "%s", tcd->device_name 79 ); 80 sysfs_create_link( 81 &device->kobj, 82 &tcd->class_device->kobj, 83 tcd->mode_name 84 ); 85 86 return tcd; 87 88 fail_with_cdev: 89 cdev_del(tcd->char_device); 90 91 fail_with_tcd: 92 kfree(tcd); 93 94 return ERR_PTR(rc); 95 } 96 EXPORT_SYMBOL(register_tape_dev); 97 98 void unregister_tape_dev(struct tape_class_device *tcd) 99 { 100 if (tcd != NULL && !IS_ERR(tcd)) { 101 sysfs_remove_link( 102 &tcd->class_device->dev->kobj, 103 tcd->mode_name 104 ); 105 class_device_destroy(tape_class, tcd->char_device->dev); 106 cdev_del(tcd->char_device); 107 kfree(tcd); 108 } 109 } 110 EXPORT_SYMBOL(unregister_tape_dev); 111 112 113 static int __init tape_init(void) 114 { 115 tape_class = class_create(THIS_MODULE, "tape390"); 116 117 return 0; 118 } 119 120 static void __exit tape_exit(void) 121 { 122 class_destroy(tape_class); 123 tape_class = NULL; 124 } 125 126 postcore_initcall(tape_init); 127 module_exit(tape_exit); 128