1 /*
2 * Linux/PowerPC Real Time Clock Driver
3 *
4 * heavily based on:
5 * Linux/SPARC Real Time Clock Driver
6 * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
7 *
8 * This is a little driver that lets a user-level program access
9 * the PPC clocks chip. It is no use unless you
10 * use the modified clock utility.
11 *
12 * Get the modified clock utility from:
13 * ftp://vger.rutgers.edu/pub/linux/Sparc/userland/clock.c
14 */
15
16 #include <linux/module.h>
17 #include <linux/types.h>
18 #include <linux/errno.h>
19 #include <linux/miscdevice.h>
20 #include <linux/malloc.h>
21 #include <linux/fcntl.h>
22 #include <linux/poll.h>
23 #include <linux/init.h>
24 #include <linux/mc146818rtc.h>
25 #include <asm/system.h>
26 #include <asm/uaccess.h>
27 #include <asm/machdep.h>
28
29 #include <asm/time.h>
30
31 static int rtc_busy = 0;
32
33 /* Retrieve the current date and time from the real time clock. */
34 void get_rtc_time(struct rtc_time *t)
35 {
36 unsigned long nowtime;
37
38 nowtime = (ppc_md.get_rtc_time)();
39
40 to_tm(nowtime, t);
41
42 t->tm_year -= 1900;
43 t->tm_mon -= 1;
44 t->tm_wday -= 1;
45 }
46
47 /* Set the current date and time in the real time clock. */
48 void set_rtc_time(struct rtc_time *t)
49 {
50 unsigned long nowtime;
51
52 printk(KERN_INFO "rtc.c:set_rtc_time: %04d-%02d-%02d %02d:%02d:%02d.\n", t->tm_year+1900, t->tm_mon+1, t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec);
53
54 nowtime = mktime(t->tm_year+1900, t->tm_mon+1, t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec);
55
56 printk(KERN_INFO "rtc.c:set_rtc_time: set rtc time to %ld seconds.\n", nowtime);
57
58 (ppc_md.set_rtc_time)(nowtime);
59 }
60
61 static loff_t rtc_lseek(struct file *file, loff_t offset, int origin)
62 {
63 return -ESPIPE;
64 }
65
66 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
67 unsigned long arg)
68 {
69 struct rtc_time rtc_tm;
70
71 switch (cmd)
72 {
73 case RTC_RD_TIME:
74 if (ppc_md.get_rtc_time)
75 {
76 get_rtc_time(&rtc_tm);
77
78 if (copy_to_user((struct rtc_time*)arg, &rtc_tm, sizeof(struct rtc_time)))
79 return -EFAULT;
80
81 return 0;
82 }
83 else
84 return -EINVAL;
85
86 case RTC_SET_TIME:
87 if (!capable(CAP_SYS_TIME))
88 return -EPERM;
89
90 if (ppc_md.set_rtc_time)
91 {
92 if (copy_from_user(&rtc_tm, (struct rtc_time*)arg, sizeof(struct rtc_time)))
93 return -EFAULT;
94
95 set_rtc_time(&rtc_tm);
96
97 return 0;
98 }
99 else
100 return -EINVAL;
101
102 default:
103 return -EINVAL;
104 }
105 }
106
107 static int rtc_open(struct inode *inode, struct file *file)
108 {
109 if (rtc_busy)
110 return -EBUSY;
111
112 rtc_busy = 1;
113
114 MOD_INC_USE_COUNT;
115
116 return 0;
117 }
118
119 static int rtc_release(struct inode *inode, struct file *file)
120 {
121 MOD_DEC_USE_COUNT;
122 rtc_busy = 0;
123 return 0;
124 }
125
126 static struct file_operations rtc_fops = {
127 owner: THIS_MODULE,
128 llseek: rtc_lseek,
129 ioctl: rtc_ioctl,
130 open: rtc_open,
131 release: rtc_release
132 };
133
134 static struct miscdevice rtc_dev = { RTC_MINOR, "rtc", &rtc_fops };
135
136 EXPORT_NO_SYMBOLS;
137
138 static int __init rtc_init(void)
139 {
140 int error;
141
142 error = misc_register(&rtc_dev);
143 if (error) {
144 printk(KERN_ERR "rtc: unable to get misc minor\n");
145 return error;
146 }
147
148 return 0;
149 }
150
151 static void __exit rtc_exit(void)
152 {
153 misc_deregister(&rtc_dev);
154 }
155
156 module_init(rtc_init);
157 module_exit(rtc_exit);
158
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