8250: Fix lock warning (and possible crash)
[linux-2.6-block.git] / arch / m68k / bvme6000 / rtc.c
CommitLineData
1da177e4
LT
1/*
2 * Real Time Clock interface for Linux on the BVME6000
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>
122bc5ea 13#include <linux/smp_lock.h>
1da177e4 14#include <linux/ioport.h>
a9415644 15#include <linux/capability.h>
1da177e4
LT
16#include <linux/fcntl.h>
17#include <linux/init.h>
18#include <linux/poll.h>
573fc113 19#include <linux/module.h>
1da177e4
LT
20#include <linux/mc146818rtc.h> /* For struct rtc_time and ioctls, etc */
21#include <linux/smp_lock.h>
b8e31edc 22#include <linux/bcd.h>
1da177e4
LT
23#include <asm/bvme6000hw.h>
24
25#include <asm/io.h>
26#include <asm/uaccess.h>
27#include <asm/system.h>
28#include <asm/setup.h>
29
30/*
31 * We sponge a minor off of the misc major. No need slurping
32 * up another valuable major dev number for this. If you add
33 * an ioctl, make sure you don't conflict with SPARC's RTC
34 * ioctls.
35 */
36
1da177e4
LT
37static unsigned char days_in_mo[] =
38{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
39
40static char rtc_status;
41
42static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
43 unsigned long arg)
44{
45 volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
46 unsigned char msr;
47 unsigned long flags;
48 struct rtc_time wtime;
1b7bb54a 49 void __user *argp = (void __user *)arg;
1da177e4
LT
50
51 switch (cmd) {
52 case RTC_RD_TIME: /* Read the time/date from RTC */
53 {
54 local_irq_save(flags);
55 /* Ensure clock and real-time-mode-register are accessible */
56 msr = rtc->msr & 0xc0;
57 rtc->msr = 0x40;
58 memset(&wtime, 0, sizeof(struct rtc_time));
59 do {
60 wtime.tm_sec = BCD2BIN(rtc->bcd_sec);
61 wtime.tm_min = BCD2BIN(rtc->bcd_min);
62 wtime.tm_hour = BCD2BIN(rtc->bcd_hr);
63 wtime.tm_mday = BCD2BIN(rtc->bcd_dom);
64 wtime.tm_mon = BCD2BIN(rtc->bcd_mth)-1;
65 wtime.tm_year = BCD2BIN(rtc->bcd_year);
66 if (wtime.tm_year < 70)
67 wtime.tm_year += 100;
68 wtime.tm_wday = BCD2BIN(rtc->bcd_dow)-1;
69 } while (wtime.tm_sec != BCD2BIN(rtc->bcd_sec));
70 rtc->msr = msr;
71 local_irq_restore(flags);
1b7bb54a 72 return copy_to_user(argp, &wtime, sizeof wtime) ?
1da177e4
LT
73 -EFAULT : 0;
74 }
75 case RTC_SET_TIME: /* Set the RTC */
76 {
77 struct rtc_time rtc_tm;
78 unsigned char mon, day, hrs, min, sec, leap_yr;
79 unsigned int yrs;
80
81 if (!capable(CAP_SYS_ADMIN))
82 return -EACCES;
83
1b7bb54a 84 if (copy_from_user(&rtc_tm, argp, sizeof(struct rtc_time)))
1da177e4
LT
85 return -EFAULT;
86
87 yrs = rtc_tm.tm_year;
88 if (yrs < 1900)
89 yrs += 1900;
90 mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
91 day = rtc_tm.tm_mday;
92 hrs = rtc_tm.tm_hour;
93 min = rtc_tm.tm_min;
94 sec = rtc_tm.tm_sec;
95
96 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
97
98 if ((mon > 12) || (mon < 1) || (day == 0))
99 return -EINVAL;
100
101 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
102 return -EINVAL;
103
104 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
105 return -EINVAL;
106
107 if (yrs >= 2070)
108 return -EINVAL;
109
110 local_irq_save(flags);
111 /* Ensure clock and real-time-mode-register are accessible */
112 msr = rtc->msr & 0xc0;
113 rtc->msr = 0x40;
114
115 rtc->t0cr_rtmr = yrs%4;
116 rtc->bcd_tenms = 0;
117 rtc->bcd_sec = BIN2BCD(sec);
118 rtc->bcd_min = BIN2BCD(min);
119 rtc->bcd_hr = BIN2BCD(hrs);
120 rtc->bcd_dom = BIN2BCD(day);
121 rtc->bcd_mth = BIN2BCD(mon);
122 rtc->bcd_year = BIN2BCD(yrs%100);
123 if (rtc_tm.tm_wday >= 0)
124 rtc->bcd_dow = BIN2BCD(rtc_tm.tm_wday+1);
125 rtc->t0cr_rtmr = yrs%4 | 0x08;
126
127 rtc->msr = msr;
128 local_irq_restore(flags);
129 return 0;
130 }
131 default:
132 return -EINVAL;
133 }
134}
135
136/*
137 * We enforce only one user at a time here with the open/close.
138 * Also clear the previous interrupt data on an open, and clean
139 * up things on a close.
140 */
141
142static int rtc_open(struct inode *inode, struct file *file)
143{
122bc5ea
AB
144 lock_kernel();
145 if(rtc_status) {
146 unlock_kernel();
1da177e4 147 return -EBUSY;
122bc5ea 148 }
1da177e4
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149
150 rtc_status = 1;
122bc5ea 151 unlock_kernel();
1da177e4
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152 return 0;
153}
154
155static int rtc_release(struct inode *inode, struct file *file)
156{
157 lock_kernel();
158 rtc_status = 0;
159 unlock_kernel();
160 return 0;
161}
162
163/*
164 * The various file operations we support.
165 */
166
5dfe4c96 167static const struct file_operations rtc_fops = {
1da177e4
LT
168 .ioctl = rtc_ioctl,
169 .open = rtc_open,
170 .release = rtc_release,
171};
172
173static struct miscdevice rtc_dev = {
174 .minor = RTC_MINOR,
175 .name = "rtc",
176 .fops = &rtc_fops
177};
178
573fc113 179static int __init rtc_DP8570A_init(void)
1da177e4
LT
180{
181 if (!MACH_IS_BVME6000)
182 return -ENODEV;
183
184 printk(KERN_INFO "DP8570A Real Time Clock Driver v%s\n", RTC_VERSION);
185 return misc_register(&rtc_dev);
186}
573fc113 187module_init(rtc_DP8570A_init);