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