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