File: /usr/src/linux/arch/m68k/mvme16x/rtc.c
1 /*
2 * Real Time Clock interface for Linux on the MVME16x
3 *
4 * Based on the PC driver by Paul Gortmaker.
5 */
6
7 #define RTC_VERSION "1.00"
8
9 #include <linux/types.h>
10 #include <linux/errno.h>
11 #include <linux/miscdevice.h>
12 #include <linux/slab.h>
13 #include <linux/ioport.h>
14 #include <linux/fcntl.h>
15 #include <linux/init.h>
16 #include <linux/poll.h>
17 #include <linux/mc146818rtc.h> /* For struct rtc_time and ioctls, etc */
18 #include <linux/smp_lock.h>
19 #include <asm/mvme16xhw.h>
20
21 #include <asm/io.h>
22 #include <asm/uaccess.h>
23 #include <asm/system.h>
24 #include <asm/setup.h>
25
26 /*
27 * We sponge a minor off of the misc major. No need slurping
28 * up another valuable major dev number for this. If you add
29 * an ioctl, make sure you don't conflict with SPARC's RTC
30 * ioctls.
31 */
32
33 #define BCD2BIN(val) (((val)&15) + ((val)>>4)*10)
34 #define BIN2BCD(val) ((((val)/10)<<4) + (val)%10)
35
36 static unsigned char days_in_mo[] =
37 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
38
39 static char rtc_status = 0;
40
41 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
42 unsigned long arg)
43 {
44 volatile MK48T08ptr_t rtc = (MK48T08ptr_t)MVME_RTC_BASE;
45 unsigned long flags;
46 struct rtc_time wtime;
47
48 switch (cmd) {
49 case RTC_RD_TIME: /* Read the time/date from RTC */
50 {
51 save_flags(flags);
52 cli();
53 /* Ensure clock and real-time-mode-register are accessible */
54 rtc->ctrl = RTC_READ;
55 wtime.tm_sec = BCD2BIN(rtc->bcd_sec);
56 wtime.tm_min = BCD2BIN(rtc->bcd_min);
57 wtime.tm_hour = BCD2BIN(rtc->bcd_hr);
58 wtime.tm_mday = BCD2BIN(rtc->bcd_dom);
59 wtime.tm_mon = BCD2BIN(rtc->bcd_mth)-1;
60 wtime.tm_year = BCD2BIN(rtc->bcd_year);
61 if (wtime.tm_year < 70)
62 wtime.tm_year += 100;
63 wtime.tm_wday = BCD2BIN(rtc->bcd_dow)-1;
64 rtc->ctrl = 0;
65 restore_flags(flags);
66 return copy_to_user((void *)arg, &wtime, sizeof wtime) ?
67 -EFAULT : 0;
68 }
69 case RTC_SET_TIME: /* Set the RTC */
70 {
71 struct rtc_time rtc_tm;
72 unsigned char mon, day, hrs, min, sec, leap_yr;
73 unsigned int yrs;
74
75 if (!capable(CAP_SYS_ADMIN))
76 return -EACCES;
77
78 if (copy_from_user(&rtc_tm, (struct rtc_time*)arg,
79 sizeof(struct rtc_time)))
80 return -EFAULT;
81
82 yrs = rtc_tm.tm_year;
83 if (yrs < 1900)
84 yrs += 1900;
85 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
86 day = rtc_tm.tm_mday;
87 hrs = rtc_tm.tm_hour;
88 min = rtc_tm.tm_min;
89 sec = rtc_tm.tm_sec;
90
91 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
92
93 if ((mon > 12) || (day == 0))
94 return -EINVAL;
95
96 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
97 return -EINVAL;
98
99 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
100 return -EINVAL;
101
102 if (yrs >= 2070)
103 return -EINVAL;
104
105 save_flags(flags);
106 cli();
107 rtc->ctrl = RTC_WRITE;
108
109 rtc->bcd_sec = BIN2BCD(sec);
110 rtc->bcd_min = BIN2BCD(min);
111 rtc->bcd_hr = BIN2BCD(hrs);
112 rtc->bcd_dom = BIN2BCD(day);
113 rtc->bcd_mth = BIN2BCD(mon);
114 rtc->bcd_year = BIN2BCD(yrs%100);
115
116 rtc->ctrl = 0;
117 restore_flags(flags);
118 return 0;
119 }
120 default:
121 return -EINVAL;
122 }
123 }
124
125 /*
126 * We enforce only one user at a time here with the open/close.
127 * Also clear the previous interrupt data on an open, and clean
128 * up things on a close.
129 */
130
131 static int rtc_open(struct inode *inode, struct file *file)
132 {
133 if(rtc_status)
134 return -EBUSY;
135
136 rtc_status = 1;
137 return 0;
138 }
139
140 static int rtc_release(struct inode *inode, struct file *file)
141 {
142 lock_kernel();
143 rtc_status = 0;
144 unlock_kernel();
145 return 0;
146 }
147
148 /*
149 * The various file operations we support.
150 */
151
152 static struct file_operations rtc_fops = {
153 ioctl: rtc_ioctl,
154 open: rtc_open,
155 release: rtc_release,
156 };
157
158 static struct miscdevice rtc_dev=
159 {
160 RTC_MINOR,
161 "rtc",
162 &rtc_fops
163 };
164
165 int __init rtc_MK48T08_init(void)
166 {
167 if (!MACH_IS_MVME16x)
168 return -ENODEV;
169
170 printk(KERN_INFO "MK48T08 Real Time Clock Driver v%s\n", RTC_VERSION);
171 misc_register(&rtc_dev);
172 return 0;
173 }
174
175