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
36static unsigned char days_in_mo[] =
37{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
38
39static char rtc_status = 0;
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		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
131static 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
140static 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
152static struct file_operations rtc_fops = {
153	ioctl:		rtc_ioctl,
154	open:		rtc_open,
155	release:	rtc_release,
156};
157
158static struct miscdevice rtc_dev=
159{
160	RTC_MINOR,
161	"rtc",
162	&rtc_fops
163};
164
165int __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