blob: 8a2425069088240e0e87031dd1c103108eca5eb7 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
36static const unsigned char days_in_mo[] =
37{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
38
39static atomic_t rtc_ready = ATOMIC_INIT(1);
40
41static 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 local_irq_save(flags);
52 /* Ensure clock and real-time-mode-register are accessible */
53 rtc->ctrl = RTC_READ;
54 memset(&wtime, 0, sizeof(struct rtc_time));
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 local_irq_restore(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 local_irq_save(flags);
106 rtc->ctrl = RTC_WRITE;
107
108 rtc->bcd_sec = BIN2BCD(sec);
109 rtc->bcd_min = BIN2BCD(min);
110 rtc->bcd_hr = BIN2BCD(hrs);
111 rtc->bcd_dom = BIN2BCD(day);
112 rtc->bcd_mth = BIN2BCD(mon);
113 rtc->bcd_year = BIN2BCD(yrs%100);
114
115 rtc->ctrl = 0;
116 local_irq_restore(flags);
117 return 0;
118 }
119 default:
120 return -EINVAL;
121 }
122}
123
124/*
125 * We enforce only one user at a time here with the open/close.
126 * Also clear the previous interrupt data on an open, and clean
127 * up things on a close.
128 */
129
130static int rtc_open(struct inode *inode, struct file *file)
131{
132 if( !atomic_dec_and_test(&rtc_ready) )
133 {
134 atomic_inc( &rtc_ready );
135 return -EBUSY;
136 }
137
138 return 0;
139}
140
141static int rtc_release(struct inode *inode, struct file *file)
142{
143 atomic_inc( &rtc_ready );
144 return 0;
145}
146
147/*
148 * The various file operations we support.
149 */
150
151static struct file_operations rtc_fops = {
152 .ioctl = rtc_ioctl,
153 .open = rtc_open,
154 .release = rtc_release,
155};
156
157static struct miscdevice rtc_dev=
158{
159 .minor = RTC_MINOR,
160 .name = "rtc",
161 .fops = &rtc_fops
162};
163
164int __init rtc_MK48T08_init(void)
165{
166 if (!MACH_IS_MVME16x)
167 return -ENODEV;
168
169 printk(KERN_INFO "MK48T08 Real Time Clock Driver v%s\n", RTC_VERSION);
170 return misc_register(&rtc_dev);
171}
172