aboutsummaryrefslogtreecommitdiffstats
path: root/arch/m68k/atari/time.c
blob: 6df7fb60dfea5af07a03950b62dc3d200c77a600 (plain) (blame)
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
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
/*
 * linux/arch/m68k/atari/time.c
 *
 * Atari time and real time clock stuff
 *
 * Assembled of parts of former atari/config.c 97-12-18 by Roman Hodek
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 */

#include <linux/types.h>
#include <linux/mc146818rtc.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/rtc.h>
#include <linux/bcd.h>

#include <asm/atariints.h>

void __init
atari_sched_init(irqreturn_t (*timer_routine)(int, void *, struct pt_regs *))
{
    /* set Timer C data Register */
    mfp.tim_dt_c = INT_TICKS;
    /* start timer C, div = 1:100 */
    mfp.tim_ct_cd = (mfp.tim_ct_cd & 15) | 0x60;
    /* install interrupt service routine for MFP Timer C */
    request_irq(IRQ_MFP_TIMC, timer_routine, IRQ_TYPE_SLOW,
                "timer", timer_routine);
}

/* ++andreas: gettimeoffset fixed to check for pending interrupt */

#define TICK_SIZE 10000

/* This is always executed with interrupts disabled.  */
unsigned long atari_gettimeoffset (void)
{
  unsigned long ticks, offset = 0;

  /* read MFP timer C current value */
  ticks = mfp.tim_dt_c;
  /* The probability of underflow is less than 2% */
  if (ticks > INT_TICKS - INT_TICKS / 50)
    /* Check for pending timer interrupt */
    if (mfp.int_pn_b & (1 << 5))
      offset = TICK_SIZE;

  ticks = INT_TICKS - ticks;
  ticks = ticks * 10000L / INT_TICKS;

  return ticks + offset;
}


static void mste_read(struct MSTE_RTC *val)
{
#define COPY(v) val->v=(mste_rtc.v & 0xf)
	do {
		COPY(sec_ones) ; COPY(sec_tens) ; COPY(min_ones) ;
		COPY(min_tens) ; COPY(hr_ones) ; COPY(hr_tens) ;
		COPY(weekday) ; COPY(day_ones) ; COPY(day_tens) ;
		COPY(mon_ones) ; COPY(mon_tens) ; COPY(year_ones) ;
		COPY(year_tens) ;
	/* prevent from reading the clock while it changed */
	} while (val->sec_ones != (mste_rtc.sec_ones & 0xf));
#undef COPY
}

static void mste_write(struct MSTE_RTC *val)
{
#define COPY(v) mste_rtc.v=val->v
	do {
		COPY(sec_ones) ; COPY(sec_tens) ; COPY(min_ones) ;
		COPY(min_tens) ; COPY(hr_ones) ; COPY(hr_tens) ;
		COPY(weekday) ; COPY(day_ones) ; COPY(day_tens) ;
		COPY(mon_ones) ; COPY(mon_tens) ; COPY(year_ones) ;
		COPY(year_tens) ;
	/* prevent from writing the clock while it changed */
	} while (val->sec_ones != (mste_rtc.sec_ones & 0xf));
#undef COPY
}

#define	RTC_READ(reg)				\
    ({	unsigned char	__val;			\
		(void) atari_writeb(reg,&tt_rtc.regsel);	\
		__val = tt_rtc.data;		\
		__val;				\
	})

#define	RTC_WRITE(reg,val)			\
    do {					\
		atari_writeb(reg,&tt_rtc.regsel);	\
		tt_rtc.data = (val);		\
	} while(0)


#define HWCLK_POLL_INTERVAL	5

int atari_mste_hwclk( int op, struct rtc_time *t )
{
    int hour, year;
    int hr24=0;
    struct MSTE_RTC val;

    mste_rtc.mode=(mste_rtc.mode | 1);
    hr24=mste_rtc.mon_tens & 1;
    mste_rtc.mode=(mste_rtc.mode & ~1);

    if (op) {
        /* write: prepare values */

        val.sec_ones = t->tm_sec % 10;
        val.sec_tens = t->tm_sec / 10;
        val.min_ones = t->tm_min % 10;
        val.min_tens = t->tm_min / 10;
        hour = t->tm_hour;
        if (!hr24) {
	    if (hour > 11)
		hour += 20 - 12;
	    if (hour == 0 || hour == 20)
		hour += 12;
        }
        val.hr_ones = hour % 10;
        val.hr_tens = hour / 10;
        val.day_ones = t->tm_mday % 10;
        val.day_tens = t->tm_mday / 10;
        val.mon_ones = (t->tm_mon+1) % 10;
        val.mon_tens = (t->tm_mon+1) / 10;
        year = t->tm_year - 80;
        val.year_ones = year % 10;
        val.year_tens = year / 10;
        val.weekday = t->tm_wday;
        mste_write(&val);
        mste_rtc.mode=(mste_rtc.mode | 1);
        val.year_ones = (year % 4);	/* leap year register */
        mste_rtc.mode=(mste_rtc.mode & ~1);
    }
    else {
        mste_read(&val);
        t->tm_sec = val.sec_ones + val.sec_tens * 10;
        t->tm_min = val.min_ones + val.min_tens * 10;
        hour = val.hr_ones + val.hr_tens * 10;
	if (!hr24) {
	    if (hour == 12 || hour == 12 + 20)
		hour -= 12;
	    if (hour >= 20)
                hour += 12 - 20;
        }
	t->tm_hour = hour;
	t->tm_mday = val.day_ones + val.day_tens * 10;
        t->tm_mon  = val.mon_ones + val.mon_tens * 10 - 1;
        t->tm_year = val.year_ones + val.year_tens * 10 + 80;
        t->tm_wday = val.weekday;
    }
    return 0;
}

int atari_tt_hwclk( int op, struct rtc_time *t )
{
    int sec=0, min=0, hour=0, day=0, mon=0, year=0, wday=0;
    unsigned long	flags;
    unsigned char	ctrl;
    int pm = 0;

    ctrl = RTC_READ(RTC_CONTROL); /* control registers are
                                   * independent from the UIP */

    if (op) {
        /* write: prepare values */

        sec  = t->tm_sec;
        min  = t->tm_min;
        hour = t->tm_hour;
        day  = t->tm_mday;
        mon  = t->tm_mon + 1;
        year = t->tm_year - atari_rtc_year_offset;
        wday = t->tm_wday + (t->tm_wday >= 0);

        if (!(ctrl & RTC_24H)) {
	    if (hour > 11) {
		pm = 0x80;
		if (hour != 12)
		    hour -= 12;
	    }
	    else if (hour == 0)
		hour = 12;
        }

        if (!(ctrl & RTC_DM_BINARY)) {
            BIN_TO_BCD(sec);
            BIN_TO_BCD(min);
            BIN_TO_BCD(hour);
            BIN_TO_BCD(day);
            BIN_TO_BCD(mon);
            BIN_TO_BCD(year);
            if (wday >= 0) BIN_TO_BCD(wday);
        }
    }

    /* Reading/writing the clock registers is a bit critical due to
     * the regular update cycle of the RTC. While an update is in
     * progress, registers 0..9 shouldn't be touched.
     * The problem is solved like that: If an update is currently in
     * progress (the UIP bit is set), the process sleeps for a while
     * (50ms). This really should be enough, since the update cycle
     * normally needs 2 ms.
     * If the UIP bit reads as 0, we have at least 244 usecs until the
     * update starts. This should be enough... But to be sure,
     * additionally the RTC_SET bit is set to prevent an update cycle.
     */

    while( RTC_READ(RTC_FREQ_SELECT) & RTC_UIP ) {
        current->state = TASK_INTERRUPTIBLE;
        schedule_timeout(HWCLK_POLL_INTERVAL);
    }

    local_irq_save(flags);
    RTC_WRITE( RTC_CONTROL, ctrl | RTC_SET );
    if (!op) {
        sec  = RTC_READ( RTC_SECONDS );
        min  = RTC_READ( RTC_MINUTES );
        hour = RTC_READ( RTC_HOURS );
        day  = RTC_READ( RTC_DAY_OF_MONTH );
        mon  = RTC_READ( RTC_MONTH );
        year = RTC_READ( RTC_YEAR );
        wday = RTC_READ( RTC_DAY_OF_WEEK );
    }
    else {
        RTC_WRITE( RTC_SECONDS, sec );
        RTC_WRITE( RTC_MINUTES, min );
        RTC_WRITE( RTC_HOURS, hour + pm);
        RTC_WRITE( RTC_DAY_OF_MONTH, day );
        RTC_WRITE( RTC_MONTH, mon );
        RTC_WRITE( RTC_YEAR, year );
        if (wday >= 0) RTC_WRITE( RTC_DAY_OF_WEEK, wday );
    }
    RTC_WRITE( RTC_CONTROL, ctrl & ~RTC_SET );
    local_irq_restore(flags);

    if (!op) {
        /* read: adjust values */

        if (hour & 0x80) {
	    hour &= ~0x80;
	    pm = 1;
	}

	if (!(ctrl & RTC_DM_BINARY)) {
            BCD_TO_BIN(sec);
            BCD_TO_BIN(min);
            BCD_TO_BIN(hour);
            BCD_TO_BIN(day);
            BCD_TO_BIN(mon);
            BCD_TO_BIN(year);
            BCD_TO_BIN(wday);
        }

        if (!(ctrl & RTC_24H)) {
	    if (!pm && hour == 12)
		hour = 0;
	    else if (pm && hour != 12)
		hour += 12;
        }

        t->tm_sec  = sec;
        t->tm_min  = min;
        t->tm_hour = hour;
        t->tm_mday = day;
        t->tm_mon  = mon - 1;
        t->tm_year = year + atari_rtc_year_offset;
        t->tm_wday = wday - 1;
    }

    return( 0 );
}


int atari_mste_set_clock_mmss (unsigned long nowtime)
{
    short real_seconds = nowtime % 60, real_minutes = (nowtime / 60) % 60;
    struct MSTE_RTC val;
    unsigned char rtc_minutes;

    mste_read(&val);
    rtc_minutes= val.min_ones + val.min_tens * 10;
    if ((rtc_minutes < real_minutes
         ? real_minutes - rtc_minutes
         : rtc_minutes - real_minutes) < 30)
    {
        val.sec_ones = real_seconds % 10;
        val.sec_tens = real_seconds / 10;
        val.min_ones = real_minutes % 10;
        val.min_tens = real_minutes / 10;
        mste_write(&val);
    }
    else
        return -1;
    return 0;
}

int atari_tt_set_clock_mmss (unsigned long nowtime)
{
    int retval = 0;
    short real_seconds = nowtime % 60, real_minutes = (nowtime / 60) % 60;
    unsigned char save_control, save_freq_select, rtc_minutes;

    save_control = RTC_READ (RTC_CONTROL); /* tell the clock it's being set */
    RTC_WRITE (RTC_CONTROL, save_control | RTC_SET);

    save_freq_select = RTC_READ (RTC_FREQ_SELECT); /* stop and reset prescaler */
    RTC_WRITE (RTC_FREQ_SELECT, save_freq_select | RTC_DIV_RESET2);

    rtc_minutes = RTC_READ (RTC_MINUTES);
    if (!(save_control & RTC_DM_BINARY))
        BCD_TO_BIN (rtc_minutes);

    /* Since we're only adjusting minutes and seconds, don't interfere
       with hour overflow.  This avoids messing with unknown time zones
       but requires your RTC not to be off by more than 30 minutes.  */
    if ((rtc_minutes < real_minutes
         ? real_minutes - rtc_minutes
         : rtc_minutes - real_minutes) < 30)
        {
            if (!(save_control & RTC_DM_BINARY))
                {
                    BIN_TO_BCD (real_seconds);
                    BIN_TO_BCD (real_minutes);
                }
            RTC_WRITE (RTC_SECONDS, real_seconds);
            RTC_WRITE (RTC_MINUTES, real_minutes);
        }
    else
        retval = -1;

    RTC_WRITE (RTC_FREQ_SELECT, save_freq_select);
    RTC_WRITE (RTC_CONTROL, save_control);
    return retval;
}

/*
 * Local variables:
 *  c-indent-level: 4
 *  tab-width: 8
 * End:
 */