drivers/rtc/rtc-sysfs.c

   1 /*
   2  * RTC subsystem, sysfs interface
   3  *
   4  * Copyright (C) 2005 Tower Technologies
   5  * Author: Alessandro Zummo <a.zummo@towertech.it>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10 */
  11
  12 #include <linux/module.h>
  13 #include <linux/rtc.h>
  14
  15 /* device attributes */
  16
  17 static ssize_t rtc_sysfs_show_name(struct class_device *dev, char *buf)
  18 {
  19         return sprintf(buf, "%s\n", to_rtc_device(dev)->name);
  20 }
  21 static CLASS_DEVICE_ATTR(name, S_IRUGO, rtc_sysfs_show_name, NULL);
  22
  23 static ssize_t rtc_sysfs_show_date(struct class_device *dev, char *buf)
  24 {
  25         ssize_t retval;
  26         struct rtc_time tm;
  27
  28         retval = rtc_read_time(dev, &tm);
  29         if (retval == 0) {
  30                 retval = sprintf(buf, "%04d-%02d-%02d\n",
  31                         tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
  32         }
  33
  34         return retval;
  35 }
  36 static CLASS_DEVICE_ATTR(date, S_IRUGO, rtc_sysfs_show_date, NULL);
  37
  38 static ssize_t rtc_sysfs_show_time(struct class_device *dev, char *buf)
  39 {
  40         ssize_t retval;
  41         struct rtc_time tm;
  42
  43         retval = rtc_read_time(dev, &tm);
  44         if (retval == 0) {
  45                 retval = sprintf(buf, "%02d:%02d:%02d\n",
  46                         tm.tm_hour, tm.tm_min, tm.tm_sec);
  47         }
  48
  49         return retval;
  50 }
  51 static CLASS_DEVICE_ATTR(time, S_IRUGO, rtc_sysfs_show_time, NULL);
  52
  53 static ssize_t rtc_sysfs_show_since_epoch(struct class_device *dev, char *buf)
  54 {
  55         ssize_t retval;
  56         struct rtc_time tm;
  57
  58         retval = rtc_read_time(dev, &tm);
  59         if (retval == 0) {
  60                 unsigned long time;
  61                 rtc_tm_to_time(&tm, &time);
  62                 retval = sprintf(buf, "%lu\n", time);
  63         }
  64
  65         return retval;
  66 }
  67 static CLASS_DEVICE_ATTR(since_epoch, S_IRUGO, rtc_sysfs_show_since_epoch, NULL);
  68
  69 static struct attribute *rtc_attrs[] = {
  70         &class_device_attr_name.attr,
  71         &class_device_attr_date.attr,
  72         &class_device_attr_time.attr,
  73         &class_device_attr_since_epoch.attr,
  74         NULL,
  75 };
  76
  77 static struct attribute_group rtc_attr_group = {
  78         .attrs = rtc_attrs,
  79 };
  80
  81 static int rtc_sysfs_add_device(struct class_device *class_dev,
  82                                         struct class_interface *class_intf)
  83 {
  84         int err;
  85
  86         dev_dbg(class_dev->dev, "rtc intf: sysfs\n");
  87
  88         err = sysfs_create_group(&class_dev->kobj, &rtc_attr_group);
  89         if (err)
  90                 dev_err(class_dev->dev,
  91                         "failed to create sysfs attributes\n");
  92
  93         return err;
  94 }
  95
  96 static void rtc_sysfs_remove_device(struct class_device *class_dev,
  97                                 struct class_interface *class_intf)
  98 {
  99         sysfs_remove_group(&class_dev->kobj, &rtc_attr_group);
 100 }
 101
 102 /* interface registration */
 103
 104 static struct class_interface rtc_sysfs_interface = {
 105         .add = &rtc_sysfs_add_device,
 106         .remove = &rtc_sysfs_remove_device,
 107 };
 108
 109 static int __init rtc_sysfs_init(void)
 110 {
 111         return rtc_interface_register(&rtc_sysfs_interface);
 112 }
 113
 114 static void __exit rtc_sysfs_exit(void)
 115 {
 116         class_interface_unregister(&rtc_sysfs_interface);
 117 }
 118
 119 subsys_initcall(rtc_sysfs_init);
 120 module_exit(rtc_sysfs_exit);
 121
 122 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 123 MODULE_DESCRIPTION("RTC class sysfs interface");
 124 MODULE_LICENSE("GPL");