summaryrefslogtreecommitdiffstats
path: root/arch/m68k/bvme6000/rtc.c
blob: e4f1faffe32bad16b950dfd51037077d6df372eb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/*
 *	Real Time Clock interface for Linux on the BVME6000
 *
 * Based on the PC driver by Paul Gortmaker.
 */

#define RTC_VERSION		"1.00"

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/ioport.h>
#include <linux/capability.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/module.h>
#include <linux/rtc.h>	/* For struct rtc_time and ioctls, etc */
#include <linux/bcd.h>
#include <asm/bvme6000hw.h>

#include <asm/io.h>
#include <linux/uaccess.h>
#include <asm/setup.h>

/*
 *	We sponge a minor off of the misc major. No need slurping
 *	up another valuable major dev number for this. If you add
 *	an ioctl, make sure you don't conflict with SPARC's RTC
 *	ioctls.
 */

static unsigned char days_in_mo[] =
{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

static atomic_t rtc_status = ATOMIC_INIT(1);

static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
	unsigned char msr;
	unsigned long flags;
	struct rtc_time wtime;
	void __user *argp = (void __user *)arg;

	switch (cmd) {
	case RTC_RD_TIME:	/* Read the time/date from RTC	*/
	{
		local_irq_save(flags);
		/* Ensure clock and real-time-mode-register are accessible */
		msr = rtc->msr & 0xc0;
		rtc->msr = 0x40;
		memset(&wtime, 0, sizeof(struct rtc_time));
		do {
			wtime.tm_sec =  bcd2bin(rtc->bcd_sec);
			wtime.tm_min =  bcd2bin(rtc->bcd_min);
			wtime.tm_hour = bcd2bin(rtc->bcd_hr);
			wtime.tm_mday =  bcd2bin(rtc->bcd_dom);
			wtime.tm_mon =  bcd2bin(rtc->bcd_mth)-1;
			wtime.tm_year = bcd2bin(rtc->bcd_year);
			if (wtime.tm_year < 70)
				wtime.tm_year += 100;
			wtime.tm_wday = bcd2bin(rtc->bcd_dow)-1;
		} while (wtime.tm_sec != bcd2bin(rtc->bcd_sec));
		rtc->msr = msr;
		local_irq_restore(flags);
		return copy_to_user(argp, &wtime, sizeof wtime) ?
								-EFAULT : 0;
	}
	case RTC_SET_TIME:	/* Set the RTC */
	{
		struct rtc_time rtc_tm;
		unsigned char mon, day, hrs, min, sec, leap_yr;
		unsigned int yrs;

		if (!capable(CAP_SYS_ADMIN))
			return -EACCES;

		if (copy_from_user(&rtc_tm, argp, sizeof(struct rtc_time)))
			return -EFAULT;

		yrs = rtc_tm.tm_year;
		if (yrs < 1900)
			yrs += 1900;
		mon = rtc_tm.tm_mon + 1;   /* tm_mon starts at zero */
		day = rtc_tm.tm_mday;
		hrs = rtc_tm.tm_hour;
		min = rtc_tm.tm_min;
		sec = rtc_tm.tm_sec;

		leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));

		if ((mon > 12) || (mon < 1) || (day == 0))
			return -EINVAL;

		if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
			return -EINVAL;

		if ((hrs >= 24) || (min >= 60) || (sec >= 60))
			return -EINVAL;

		if (yrs >= 2070)
			return -EINVAL;

		local_irq_save(flags);
		/* Ensure clock and real-time-mode-register are accessible */
		msr = rtc->msr & 0xc0;
		rtc->msr = 0x40;

		rtc->t0cr_rtmr = yrs%4;
		rtc->bcd_tenms = 0;
		rtc->bcd_sec   = bin2bcd(sec);
		rtc->bcd_min   = bin2bcd(min);
		rtc->bcd_hr    = bin2bcd(hrs);
		rtc->bcd_dom   = bin2bcd(day);
		rtc->bcd_mth   = bin2bcd(mon);
		rtc->bcd_year  = bin2bcd(yrs%100);
		if (rtc_tm.tm_wday >= 0)
			rtc->bcd_dow = bin2bcd(rtc_tm.tm_wday+1);
		rtc->t0cr_rtmr = yrs%4 | 0x08;

		rtc->msr = msr;
		local_irq_restore(flags);
		return 0;
	}
	default:
		return -EINVAL;
	}
}

/*
 * We enforce only one user at a time here with the open/close.
 */
static int rtc_open(struct inode *inode, struct file *file)
{
	if (!atomic_dec_and_test(&rtc_status)) {
		atomic_inc(&rtc_status);
		return -EBUSY;
	}
	return 0;
}

static int rtc_release(struct inode *inode, struct file *file)
{
	atomic_inc(&rtc_status);
	return 0;
}

/*
 *	The various file operations we support.
 */

static const struct file_operations rtc_fops = {
	.unlocked_ioctl	= rtc_ioctl,
	.open		= rtc_open,
	.release	= rtc_release,
	.llseek		= noop_llseek,
};

static struct miscdevice rtc_dev = {
	.minor =	RTC_MINOR,
	.name =		"rtc",
	.fops =		&rtc_fops
};

static int __init rtc_DP8570A_init(void)
{
	if (!MACH_IS_BVME6000)
		return -ENODEV;

	pr_info("DP8570A Real Time Clock Driver v%s\n", RTC_VERSION);
	return misc_register(&rtc_dev);
}
module_init(rtc_DP8570A_init);