2 * linux/arch/m68k/atari/time.c
4 * Atari time and real time clock stuff
6 * Assembled of parts of former atari/config.c 97-12-18 by Roman Hodek
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file COPYING in the main directory of this archive
13 #include <linux/types.h>
14 #include <linux/mc146818rtc.h>
15 #include <linux/interrupt.h>
16 #include <linux/init.h>
17 #include <linux/rtc.h>
18 #include <linux/bcd.h>
19 #include <linux/delay.h>
21 #include <asm/atariints.h>
24 atari_sched_init(irq_handler_t timer_routine)
26 /* set Timer C data Register */
27 mfp.tim_dt_c = INT_TICKS;
28 /* start timer C, div = 1:100 */
29 mfp.tim_ct_cd = (mfp.tim_ct_cd & 15) | 0x60;
30 /* install interrupt service routine for MFP Timer C */
31 request_irq(IRQ_MFP_TIMC, timer_routine, IRQ_TYPE_SLOW,
32 "timer", timer_routine);
35 /* ++andreas: gettimeoffset fixed to check for pending interrupt */
37 #define TICK_SIZE 10000
39 /* This is always executed with interrupts disabled. */
40 unsigned long atari_gettimeoffset (void)
42 unsigned long ticks, offset = 0;
44 /* read MFP timer C current value */
46 /* The probability of underflow is less than 2% */
47 if (ticks > INT_TICKS - INT_TICKS / 50)
48 /* Check for pending timer interrupt */
49 if (mfp.int_pn_b & (1 << 5))
52 ticks = INT_TICKS - ticks;
53 ticks = ticks * 10000L / INT_TICKS;
55 return ticks + offset;
59 static void mste_read(struct MSTE_RTC *val)
61 #define COPY(v) val->v=(mste_rtc.v & 0xf)
63 COPY(sec_ones) ; COPY(sec_tens) ; COPY(min_ones) ;
64 COPY(min_tens) ; COPY(hr_ones) ; COPY(hr_tens) ;
65 COPY(weekday) ; COPY(day_ones) ; COPY(day_tens) ;
66 COPY(mon_ones) ; COPY(mon_tens) ; COPY(year_ones) ;
68 /* prevent from reading the clock while it changed */
69 } while (val->sec_ones != (mste_rtc.sec_ones & 0xf));
73 static void mste_write(struct MSTE_RTC *val)
75 #define COPY(v) mste_rtc.v=val->v
77 COPY(sec_ones) ; COPY(sec_tens) ; COPY(min_ones) ;
78 COPY(min_tens) ; COPY(hr_ones) ; COPY(hr_tens) ;
79 COPY(weekday) ; COPY(day_ones) ; COPY(day_tens) ;
80 COPY(mon_ones) ; COPY(mon_tens) ; COPY(year_ones) ;
82 /* prevent from writing the clock while it changed */
83 } while (val->sec_ones != (mste_rtc.sec_ones & 0xf));
87 #define RTC_READ(reg) \
88 ({ unsigned char __val; \
89 (void) atari_writeb(reg,&tt_rtc.regsel); \
90 __val = tt_rtc.data; \
94 #define RTC_WRITE(reg,val) \
96 atari_writeb(reg,&tt_rtc.regsel); \
97 tt_rtc.data = (val); \
101 #define HWCLK_POLL_INTERVAL 5
103 int atari_mste_hwclk( int op, struct rtc_time *t )
109 mste_rtc.mode=(mste_rtc.mode | 1);
110 hr24=mste_rtc.mon_tens & 1;
111 mste_rtc.mode=(mste_rtc.mode & ~1);
114 /* write: prepare values */
116 val.sec_ones = t->tm_sec % 10;
117 val.sec_tens = t->tm_sec / 10;
118 val.min_ones = t->tm_min % 10;
119 val.min_tens = t->tm_min / 10;
124 if (hour == 0 || hour == 20)
127 val.hr_ones = hour % 10;
128 val.hr_tens = hour / 10;
129 val.day_ones = t->tm_mday % 10;
130 val.day_tens = t->tm_mday / 10;
131 val.mon_ones = (t->tm_mon+1) % 10;
132 val.mon_tens = (t->tm_mon+1) / 10;
133 year = t->tm_year - 80;
134 val.year_ones = year % 10;
135 val.year_tens = year / 10;
136 val.weekday = t->tm_wday;
138 mste_rtc.mode=(mste_rtc.mode | 1);
139 val.year_ones = (year % 4); /* leap year register */
140 mste_rtc.mode=(mste_rtc.mode & ~1);
144 t->tm_sec = val.sec_ones + val.sec_tens * 10;
145 t->tm_min = val.min_ones + val.min_tens * 10;
146 hour = val.hr_ones + val.hr_tens * 10;
148 if (hour == 12 || hour == 12 + 20)
154 t->tm_mday = val.day_ones + val.day_tens * 10;
155 t->tm_mon = val.mon_ones + val.mon_tens * 10 - 1;
156 t->tm_year = val.year_ones + val.year_tens * 10 + 80;
157 t->tm_wday = val.weekday;
162 int atari_tt_hwclk( int op, struct rtc_time *t )
164 int sec=0, min=0, hour=0, day=0, mon=0, year=0, wday=0;
169 ctrl = RTC_READ(RTC_CONTROL); /* control registers are
170 * independent from the UIP */
173 /* write: prepare values */
180 year = t->tm_year - atari_rtc_year_offset;
181 wday = t->tm_wday + (t->tm_wday >= 0);
183 if (!(ctrl & RTC_24H)) {
193 if (!(ctrl & RTC_DM_BINARY)) {
196 hour = bin2bcd(hour);
199 year = bin2bcd(year);
201 wday = bin2bcd(wday);
205 /* Reading/writing the clock registers is a bit critical due to
206 * the regular update cycle of the RTC. While an update is in
207 * progress, registers 0..9 shouldn't be touched.
208 * The problem is solved like that: If an update is currently in
209 * progress (the UIP bit is set), the process sleeps for a while
210 * (50ms). This really should be enough, since the update cycle
211 * normally needs 2 ms.
212 * If the UIP bit reads as 0, we have at least 244 usecs until the
213 * update starts. This should be enough... But to be sure,
214 * additionally the RTC_SET bit is set to prevent an update cycle.
217 while( RTC_READ(RTC_FREQ_SELECT) & RTC_UIP ) {
218 if (in_atomic() || irqs_disabled())
221 schedule_timeout_interruptible(HWCLK_POLL_INTERVAL);
224 local_irq_save(flags);
225 RTC_WRITE( RTC_CONTROL, ctrl | RTC_SET );
227 sec = RTC_READ( RTC_SECONDS );
228 min = RTC_READ( RTC_MINUTES );
229 hour = RTC_READ( RTC_HOURS );
230 day = RTC_READ( RTC_DAY_OF_MONTH );
231 mon = RTC_READ( RTC_MONTH );
232 year = RTC_READ( RTC_YEAR );
233 wday = RTC_READ( RTC_DAY_OF_WEEK );
236 RTC_WRITE( RTC_SECONDS, sec );
237 RTC_WRITE( RTC_MINUTES, min );
238 RTC_WRITE( RTC_HOURS, hour + pm);
239 RTC_WRITE( RTC_DAY_OF_MONTH, day );
240 RTC_WRITE( RTC_MONTH, mon );
241 RTC_WRITE( RTC_YEAR, year );
242 if (wday >= 0) RTC_WRITE( RTC_DAY_OF_WEEK, wday );
244 RTC_WRITE( RTC_CONTROL, ctrl & ~RTC_SET );
245 local_irq_restore(flags);
248 /* read: adjust values */
255 if (!(ctrl & RTC_DM_BINARY)) {
258 hour = bcd2bin(hour);
261 year = bcd2bin(year);
262 wday = bcd2bin(wday);
265 if (!(ctrl & RTC_24H)) {
266 if (!pm && hour == 12)
268 else if (pm && hour != 12)
277 t->tm_year = year + atari_rtc_year_offset;
278 t->tm_wday = wday - 1;
285 int atari_mste_set_clock_mmss (unsigned long nowtime)
287 short real_seconds = nowtime % 60, real_minutes = (nowtime / 60) % 60;
289 unsigned char rtc_minutes;
292 rtc_minutes= val.min_ones + val.min_tens * 10;
293 if ((rtc_minutes < real_minutes
294 ? real_minutes - rtc_minutes
295 : rtc_minutes - real_minutes) < 30)
297 val.sec_ones = real_seconds % 10;
298 val.sec_tens = real_seconds / 10;
299 val.min_ones = real_minutes % 10;
300 val.min_tens = real_minutes / 10;
308 int atari_tt_set_clock_mmss (unsigned long nowtime)
311 short real_seconds = nowtime % 60, real_minutes = (nowtime / 60) % 60;
312 unsigned char save_control, save_freq_select, rtc_minutes;
314 save_control = RTC_READ (RTC_CONTROL); /* tell the clock it's being set */
315 RTC_WRITE (RTC_CONTROL, save_control | RTC_SET);
317 save_freq_select = RTC_READ (RTC_FREQ_SELECT); /* stop and reset prescaler */
318 RTC_WRITE (RTC_FREQ_SELECT, save_freq_select | RTC_DIV_RESET2);
320 rtc_minutes = RTC_READ (RTC_MINUTES);
321 if (!(save_control & RTC_DM_BINARY))
322 rtc_minutes = bcd2bin(rtc_minutes);
324 /* Since we're only adjusting minutes and seconds, don't interfere
325 with hour overflow. This avoids messing with unknown time zones
326 but requires your RTC not to be off by more than 30 minutes. */
327 if ((rtc_minutes < real_minutes
328 ? real_minutes - rtc_minutes
329 : rtc_minutes - real_minutes) < 30)
331 if (!(save_control & RTC_DM_BINARY))
333 real_seconds = bin2bcd(real_seconds);
334 real_minutes = bin2bcd(real_minutes);
336 RTC_WRITE (RTC_SECONDS, real_seconds);
337 RTC_WRITE (RTC_MINUTES, real_minutes);
342 RTC_WRITE (RTC_FREQ_SELECT, save_freq_select);
343 RTC_WRITE (RTC_CONTROL, save_control);