1 /* 2 * RTC subsystem, base class 3 * 4 * Copyright (C) 2005 Tower Technologies 5 * Author: Alessandro Zummo <a.zummo@towertech.it> 6 * 7 * class skeleton from drivers/hwmon/hwmon.c 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as 11 * published by the Free Software Foundation. 12 */ 13 14 #include <linux/module.h> 15 #include <linux/rtc.h> 16 #include <linux/kdev_t.h> 17 #include <linux/idr.h> 18 19 static DEFINE_IDR(rtc_idr); 20 static DEFINE_MUTEX(idr_lock); 21 struct class *rtc_class; 22 23 static void rtc_device_release(struct class_device *class_dev) 24 { 25 struct rtc_device *rtc = to_rtc_device(class_dev); 26 mutex_lock(&idr_lock); 27 idr_remove(&rtc_idr, rtc->id); 28 mutex_unlock(&idr_lock); 29 kfree(rtc); 30 } 31 32 /** 33 * rtc_device_register - register w/ RTC class 34 * @dev: the device to register 35 * 36 * rtc_device_unregister() must be called when the class device is no 37 * longer needed. 38 * 39 * Returns the pointer to the new struct class device. 40 */ 41 struct rtc_device *rtc_device_register(const char *name, struct device *dev, 42 struct rtc_class_ops *ops, 43 struct module *owner) 44 { 45 struct rtc_device *rtc; 46 int id, err; 47 48 if (idr_pre_get(&rtc_idr, GFP_KERNEL) == 0) { 49 err = -ENOMEM; 50 goto exit; 51 } 52 53 54 mutex_lock(&idr_lock); 55 err = idr_get_new(&rtc_idr, NULL, &id); 56 mutex_unlock(&idr_lock); 57 58 if (err < 0) 59 goto exit; 60 61 id = id & MAX_ID_MASK; 62 63 rtc = kzalloc(sizeof(struct rtc_device), GFP_KERNEL); 64 if (rtc == NULL) { 65 err = -ENOMEM; 66 goto exit_idr; 67 } 68 69 rtc->id = id; 70 rtc->ops = ops; 71 rtc->owner = owner; 72 rtc->class_dev.dev = dev; 73 rtc->class_dev.class = rtc_class; 74 rtc->class_dev.release = rtc_device_release; 75 76 mutex_init(&rtc->ops_lock); 77 spin_lock_init(&rtc->irq_lock); 78 spin_lock_init(&rtc->irq_task_lock); 79 80 strlcpy(rtc->name, name, RTC_DEVICE_NAME_SIZE); 81 snprintf(rtc->class_dev.class_id, BUS_ID_SIZE, "rtc%d", id); 82 83 err = class_device_register(&rtc->class_dev); 84 if (err) 85 goto exit_kfree; 86 87 dev_info(dev, "rtc core: registered %s as %s\n", 88 rtc->name, rtc->class_dev.class_id); 89 90 return rtc; 91 92 exit_kfree: 93 kfree(rtc); 94 95 exit_idr: 96 idr_remove(&rtc_idr, id); 97 98 exit: 99 return ERR_PTR(err); 100 } 101 EXPORT_SYMBOL_GPL(rtc_device_register); 102 103 104 /** 105 * rtc_device_unregister - removes the previously registered RTC class device 106 * 107 * @rtc: the RTC class device to destroy 108 */ 109 void rtc_device_unregister(struct rtc_device *rtc) 110 { 111 mutex_lock(&rtc->ops_lock); 112 rtc->ops = NULL; 113 mutex_unlock(&rtc->ops_lock); 114 class_device_unregister(&rtc->class_dev); 115 } 116 EXPORT_SYMBOL_GPL(rtc_device_unregister); 117 118 int rtc_interface_register(struct class_interface *intf) 119 { 120 intf->class = rtc_class; 121 return class_interface_register(intf); 122 } 123 EXPORT_SYMBOL_GPL(rtc_interface_register); 124 125 static int __init rtc_init(void) 126 { 127 rtc_class = class_create(THIS_MODULE, "rtc"); 128 if (IS_ERR(rtc_class)) { 129 printk(KERN_ERR "%s: couldn't create class\n", __FILE__); 130 return PTR_ERR(rtc_class); 131 } 132 return 0; 133 } 134 135 static void __exit rtc_exit(void) 136 { 137 class_destroy(rtc_class); 138 } 139 140 module_init(rtc_init); 141 module_exit(rtc_exit); 142 143 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towerteh.it>"); 144 MODULE_DESCRIPTION("RTC class support"); 145 MODULE_LICENSE("GPL"); 146