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 72 rc = cdev_add(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 = PTR_RET(tcd->class_device); 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