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 <linux/slab.h> 15 16#include "tape_class.h" 17 18MODULE_AUTHOR("Stefan Bader <shbader@de.ibm.com>"); 19MODULE_DESCRIPTION( 20 "(C) Copyright IBM Corp. 2004 All Rights Reserved.\n" 21 "tape_class.c" 22); 23MODULE_LICENSE("GPL"); 24 25static struct class *tape_class; 26 27/* 28 * Register a tape device and return a pointer to the cdev structure. 29 * 30 * device 31 * The pointer to the struct device of the physical (base) device. 32 * drivername 33 * The pointer to the drivers name for it's character devices. 34 * dev 35 * The intended major/minor number. The major number may be 0 to 36 * get a dynamic major number. 37 * fops 38 * The pointer to the drivers file operations for the tape device. 39 * devname 40 * The pointer to the name of the character device. 41 */ 42struct tape_class_device *register_tape_dev( 43 struct device * device, 44 dev_t dev, 45 const struct file_operations *fops, 46 char * device_name, 47 char * mode_name) 48{ 49 struct tape_class_device * tcd; 50 int rc; 51 char * s; 52 53 tcd = kzalloc(sizeof(struct tape_class_device), GFP_KERNEL); 54 if (!tcd) 55 return ERR_PTR(-ENOMEM); 56 57 strncpy(tcd->device_name, device_name, TAPECLASS_NAME_LEN); 58 for (s = strchr(tcd->device_name, '/'); s; s = strchr(s, '/')) 59 *s = '!'; 60 strncpy(tcd->mode_name, mode_name, TAPECLASS_NAME_LEN); 61 for (s = strchr(tcd->mode_name, '/'); s; s = strchr(s, '/')) 62 *s = '!'; 63 64 tcd->char_device = cdev_alloc(); 65 if (!tcd->char_device) { 66 rc = -ENOMEM; 67 goto fail_with_tcd; 68 } 69 70 tcd->char_device->owner = fops->owner; 71 tcd->char_device->ops = fops; 72 tcd->char_device->dev = dev; 73 74 rc = cdev_add(tcd->char_device, tcd->char_device->dev, 1); 75 if (rc) 76 goto fail_with_cdev; 77 78 tcd->class_device = device_create(tape_class, device, 79 tcd->char_device->dev, NULL, 80 "%s", tcd->device_name); 81 rc = IS_ERR(tcd->class_device) ? PTR_ERR(tcd->class_device) : 0; 82 if (rc) 83 goto fail_with_cdev; 84 rc = sysfs_create_link( 85 &device->kobj, 86 &tcd->class_device->kobj, 87 tcd->mode_name 88 ); 89 if (rc) 90 goto fail_with_class_device; 91 92 return tcd; 93 94fail_with_class_device: 95 device_destroy(tape_class, tcd->char_device->dev); 96 97fail_with_cdev: 98 cdev_del(tcd->char_device); 99 100fail_with_tcd: 101 kfree(tcd); 102 103 return ERR_PTR(rc); 104} 105EXPORT_SYMBOL(register_tape_dev); 106 107void unregister_tape_dev(struct device *device, struct tape_class_device *tcd) 108{ 109 if (tcd != NULL && !IS_ERR(tcd)) { 110 sysfs_remove_link(&device->kobj, tcd->mode_name); 111 device_destroy(tape_class, tcd->char_device->dev); 112 cdev_del(tcd->char_device); 113 kfree(tcd); 114 } 115} 116EXPORT_SYMBOL(unregister_tape_dev); 117 118 119static int __init tape_init(void) 120{ 121 tape_class = class_create(THIS_MODULE, "tape390"); 122 123 return 0; 124} 125 126static void __exit tape_exit(void) 127{ 128 class_destroy(tape_class); 129 tape_class = NULL; 130} 131 132postcore_initcall(tape_init); 133module_exit(tape_exit); 134