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v5.9
  1/*
  2 * linux/arch/m68k/atari/time.c
  3 *
  4 * Atari time and real time clock stuff
  5 *
  6 * Assembled of parts of former atari/config.c 97-12-18 by Roman Hodek
  7 *
  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
 10 * for more details.
 11 */
 12
 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/clocksource.h>
 20#include <linux/delay.h>
 21#include <linux/export.h>
 22
 23#include <asm/atariints.h>
 24
 25DEFINE_SPINLOCK(rtc_lock);
 26EXPORT_SYMBOL_GPL(rtc_lock);
 27
 28static u64 atari_read_clk(struct clocksource *cs);
 29
 30static struct clocksource atari_clk = {
 31	.name   = "mfp",
 32	.rating = 100,
 33	.read   = atari_read_clk,
 34	.mask   = CLOCKSOURCE_MASK(32),
 35	.flags  = CLOCK_SOURCE_IS_CONTINUOUS,
 36};
 37
 38static u32 clk_total;
 39static u8 last_timer_count;
 40
 41static irqreturn_t mfp_timer_c_handler(int irq, void *dev_id)
 42{
 43	irq_handler_t timer_routine = dev_id;
 44	unsigned long flags;
 45
 46	local_irq_save(flags);
 47	do {
 48		last_timer_count = st_mfp.tim_dt_c;
 49	} while (last_timer_count == 1);
 50	clk_total += INT_TICKS;
 51	timer_routine(0, NULL);
 52	local_irq_restore(flags);
 53
 54	return IRQ_HANDLED;
 55}
 56
 57void __init
 58atari_sched_init(irq_handler_t timer_routine)
 59{
 60    /* set Timer C data Register */
 61    st_mfp.tim_dt_c = INT_TICKS;
 62    /* start timer C, div = 1:100 */
 63    st_mfp.tim_ct_cd = (st_mfp.tim_ct_cd & 15) | 0x60;
 64    /* install interrupt service routine for MFP Timer C */
 65    if (request_irq(IRQ_MFP_TIMC, mfp_timer_c_handler, IRQF_TIMER, "timer",
 66                    timer_routine))
 67	pr_err("Couldn't register timer interrupt\n");
 68
 69    clocksource_register_hz(&atari_clk, INT_CLK);
 70}
 71
 72/* ++andreas: gettimeoffset fixed to check for pending interrupt */
 73
 74static u64 atari_read_clk(struct clocksource *cs)
 
 
 
 75{
 76	unsigned long flags;
 77	u8 count;
 78	u32 ticks;
 79
 80	local_irq_save(flags);
 81	/* Ensure that the count is monotonically decreasing, even though
 82	 * the result may briefly stop changing after counter wrap-around.
 83	 */
 84	count = min(st_mfp.tim_dt_c, last_timer_count);
 85	last_timer_count = count;
 86
 87	ticks = INT_TICKS - count;
 88	ticks += clk_total;
 89	local_irq_restore(flags);
 90
 91	return ticks;
 
 
 
 
 
 
 
 
 
 
 
 92}
 93
 94
 95static void mste_read(struct MSTE_RTC *val)
 96{
 97#define COPY(v) val->v=(mste_rtc.v & 0xf)
 98	do {
 99		COPY(sec_ones) ; COPY(sec_tens) ; COPY(min_ones) ;
100		COPY(min_tens) ; COPY(hr_ones) ; COPY(hr_tens) ;
101		COPY(weekday) ; COPY(day_ones) ; COPY(day_tens) ;
102		COPY(mon_ones) ; COPY(mon_tens) ; COPY(year_ones) ;
103		COPY(year_tens) ;
104	/* prevent from reading the clock while it changed */
105	} while (val->sec_ones != (mste_rtc.sec_ones & 0xf));
106#undef COPY
107}
108
109static void mste_write(struct MSTE_RTC *val)
110{
111#define COPY(v) mste_rtc.v=val->v
112	do {
113		COPY(sec_ones) ; COPY(sec_tens) ; COPY(min_ones) ;
114		COPY(min_tens) ; COPY(hr_ones) ; COPY(hr_tens) ;
115		COPY(weekday) ; COPY(day_ones) ; COPY(day_tens) ;
116		COPY(mon_ones) ; COPY(mon_tens) ; COPY(year_ones) ;
117		COPY(year_tens) ;
118	/* prevent from writing the clock while it changed */
119	} while (val->sec_ones != (mste_rtc.sec_ones & 0xf));
120#undef COPY
121}
122
123#define	RTC_READ(reg)				\
124    ({	unsigned char	__val;			\
125		(void) atari_writeb(reg,&tt_rtc.regsel);	\
126		__val = tt_rtc.data;		\
127		__val;				\
128	})
129
130#define	RTC_WRITE(reg,val)			\
131    do {					\
132		atari_writeb(reg,&tt_rtc.regsel);	\
133		tt_rtc.data = (val);		\
134	} while(0)
135
136
137#define HWCLK_POLL_INTERVAL	5
138
139int atari_mste_hwclk( int op, struct rtc_time *t )
140{
141    int hour, year;
142    int hr24=0;
143    struct MSTE_RTC val;
144
145    mste_rtc.mode=(mste_rtc.mode | 1);
146    hr24=mste_rtc.mon_tens & 1;
147    mste_rtc.mode=(mste_rtc.mode & ~1);
148
149    if (op) {
150        /* write: prepare values */
151
152        val.sec_ones = t->tm_sec % 10;
153        val.sec_tens = t->tm_sec / 10;
154        val.min_ones = t->tm_min % 10;
155        val.min_tens = t->tm_min / 10;
156        hour = t->tm_hour;
157        if (!hr24) {
158	    if (hour > 11)
159		hour += 20 - 12;
160	    if (hour == 0 || hour == 20)
161		hour += 12;
162        }
163        val.hr_ones = hour % 10;
164        val.hr_tens = hour / 10;
165        val.day_ones = t->tm_mday % 10;
166        val.day_tens = t->tm_mday / 10;
167        val.mon_ones = (t->tm_mon+1) % 10;
168        val.mon_tens = (t->tm_mon+1) / 10;
169        year = t->tm_year - 80;
170        val.year_ones = year % 10;
171        val.year_tens = year / 10;
172        val.weekday = t->tm_wday;
173        mste_write(&val);
174        mste_rtc.mode=(mste_rtc.mode | 1);
175        val.year_ones = (year % 4);	/* leap year register */
176        mste_rtc.mode=(mste_rtc.mode & ~1);
177    }
178    else {
179        mste_read(&val);
180        t->tm_sec = val.sec_ones + val.sec_tens * 10;
181        t->tm_min = val.min_ones + val.min_tens * 10;
182        hour = val.hr_ones + val.hr_tens * 10;
183	if (!hr24) {
184	    if (hour == 12 || hour == 12 + 20)
185		hour -= 12;
186	    if (hour >= 20)
187                hour += 12 - 20;
188        }
189	t->tm_hour = hour;
190	t->tm_mday = val.day_ones + val.day_tens * 10;
191        t->tm_mon  = val.mon_ones + val.mon_tens * 10 - 1;
192        t->tm_year = val.year_ones + val.year_tens * 10 + 80;
193        t->tm_wday = val.weekday;
194    }
195    return 0;
196}
197
198int atari_tt_hwclk( int op, struct rtc_time *t )
199{
200    int sec=0, min=0, hour=0, day=0, mon=0, year=0, wday=0;
201    unsigned long	flags;
202    unsigned char	ctrl;
203    int pm = 0;
204
205    ctrl = RTC_READ(RTC_CONTROL); /* control registers are
206                                   * independent from the UIP */
207
208    if (op) {
209        /* write: prepare values */
210
211        sec  = t->tm_sec;
212        min  = t->tm_min;
213        hour = t->tm_hour;
214        day  = t->tm_mday;
215        mon  = t->tm_mon + 1;
216        year = t->tm_year - atari_rtc_year_offset;
217        wday = t->tm_wday + (t->tm_wday >= 0);
218
219        if (!(ctrl & RTC_24H)) {
220	    if (hour > 11) {
221		pm = 0x80;
222		if (hour != 12)
223		    hour -= 12;
224	    }
225	    else if (hour == 0)
226		hour = 12;
227        }
228
229        if (!(ctrl & RTC_DM_BINARY)) {
230	    sec = bin2bcd(sec);
231	    min = bin2bcd(min);
232	    hour = bin2bcd(hour);
233	    day = bin2bcd(day);
234	    mon = bin2bcd(mon);
235	    year = bin2bcd(year);
236	    if (wday >= 0)
237		wday = bin2bcd(wday);
238        }
239    }
240
241    /* Reading/writing the clock registers is a bit critical due to
242     * the regular update cycle of the RTC. While an update is in
243     * progress, registers 0..9 shouldn't be touched.
244     * The problem is solved like that: If an update is currently in
245     * progress (the UIP bit is set), the process sleeps for a while
246     * (50ms). This really should be enough, since the update cycle
247     * normally needs 2 ms.
248     * If the UIP bit reads as 0, we have at least 244 usecs until the
249     * update starts. This should be enough... But to be sure,
250     * additionally the RTC_SET bit is set to prevent an update cycle.
251     */
252
253    while( RTC_READ(RTC_FREQ_SELECT) & RTC_UIP ) {
254	if (in_atomic() || irqs_disabled())
255	    mdelay(1);
256	else
257	    schedule_timeout_interruptible(HWCLK_POLL_INTERVAL);
258    }
259
260    local_irq_save(flags);
261    RTC_WRITE( RTC_CONTROL, ctrl | RTC_SET );
262    if (!op) {
263        sec  = RTC_READ( RTC_SECONDS );
264        min  = RTC_READ( RTC_MINUTES );
265        hour = RTC_READ( RTC_HOURS );
266        day  = RTC_READ( RTC_DAY_OF_MONTH );
267        mon  = RTC_READ( RTC_MONTH );
268        year = RTC_READ( RTC_YEAR );
269        wday = RTC_READ( RTC_DAY_OF_WEEK );
270    }
271    else {
272        RTC_WRITE( RTC_SECONDS, sec );
273        RTC_WRITE( RTC_MINUTES, min );
274        RTC_WRITE( RTC_HOURS, hour + pm);
275        RTC_WRITE( RTC_DAY_OF_MONTH, day );
276        RTC_WRITE( RTC_MONTH, mon );
277        RTC_WRITE( RTC_YEAR, year );
278        if (wday >= 0) RTC_WRITE( RTC_DAY_OF_WEEK, wday );
279    }
280    RTC_WRITE( RTC_CONTROL, ctrl & ~RTC_SET );
281    local_irq_restore(flags);
282
283    if (!op) {
284        /* read: adjust values */
285
286        if (hour & 0x80) {
287	    hour &= ~0x80;
288	    pm = 1;
289	}
290
291	if (!(ctrl & RTC_DM_BINARY)) {
292	    sec = bcd2bin(sec);
293	    min = bcd2bin(min);
294	    hour = bcd2bin(hour);
295	    day = bcd2bin(day);
296	    mon = bcd2bin(mon);
297	    year = bcd2bin(year);
298	    wday = bcd2bin(wday);
299        }
300
301        if (!(ctrl & RTC_24H)) {
302	    if (!pm && hour == 12)
303		hour = 0;
304	    else if (pm && hour != 12)
305		hour += 12;
306        }
307
308        t->tm_sec  = sec;
309        t->tm_min  = min;
310        t->tm_hour = hour;
311        t->tm_mday = day;
312        t->tm_mon  = mon - 1;
313        t->tm_year = year + atari_rtc_year_offset;
314        t->tm_wday = wday - 1;
315    }
316
317    return( 0 );
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
318}
319
320/*
321 * Local variables:
322 *  c-indent-level: 4
323 *  tab-width: 8
324 * End:
325 */
v4.6
  1/*
  2 * linux/arch/m68k/atari/time.c
  3 *
  4 * Atari time and real time clock stuff
  5 *
  6 * Assembled of parts of former atari/config.c 97-12-18 by Roman Hodek
  7 *
  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
 10 * for more details.
 11 */
 12
 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>
 20#include <linux/export.h>
 21
 22#include <asm/atariints.h>
 23
 24DEFINE_SPINLOCK(rtc_lock);
 25EXPORT_SYMBOL_GPL(rtc_lock);
 26
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 27void __init
 28atari_sched_init(irq_handler_t timer_routine)
 29{
 30    /* set Timer C data Register */
 31    st_mfp.tim_dt_c = INT_TICKS;
 32    /* start timer C, div = 1:100 */
 33    st_mfp.tim_ct_cd = (st_mfp.tim_ct_cd & 15) | 0x60;
 34    /* install interrupt service routine for MFP Timer C */
 35    if (request_irq(IRQ_MFP_TIMC, timer_routine, 0, "timer", timer_routine))
 
 36	pr_err("Couldn't register timer interrupt\n");
 
 
 37}
 38
 39/* ++andreas: gettimeoffset fixed to check for pending interrupt */
 40
 41#define TICK_SIZE 10000
 42
 43/* This is always executed with interrupts disabled.  */
 44u32 atari_gettimeoffset(void)
 45{
 46  u32 ticks, offset = 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 47
 48  /* read MFP timer C current value */
 49  ticks = st_mfp.tim_dt_c;
 50  /* The probability of underflow is less than 2% */
 51  if (ticks > INT_TICKS - INT_TICKS / 50)
 52    /* Check for pending timer interrupt */
 53    if (st_mfp.int_pn_b & (1 << 5))
 54      offset = TICK_SIZE;
 55
 56  ticks = INT_TICKS - ticks;
 57  ticks = ticks * 10000L / INT_TICKS;
 58
 59  return (ticks + offset) * 1000;
 60}
 61
 62
 63static void mste_read(struct MSTE_RTC *val)
 64{
 65#define COPY(v) val->v=(mste_rtc.v & 0xf)
 66	do {
 67		COPY(sec_ones) ; COPY(sec_tens) ; COPY(min_ones) ;
 68		COPY(min_tens) ; COPY(hr_ones) ; COPY(hr_tens) ;
 69		COPY(weekday) ; COPY(day_ones) ; COPY(day_tens) ;
 70		COPY(mon_ones) ; COPY(mon_tens) ; COPY(year_ones) ;
 71		COPY(year_tens) ;
 72	/* prevent from reading the clock while it changed */
 73	} while (val->sec_ones != (mste_rtc.sec_ones & 0xf));
 74#undef COPY
 75}
 76
 77static void mste_write(struct MSTE_RTC *val)
 78{
 79#define COPY(v) mste_rtc.v=val->v
 80	do {
 81		COPY(sec_ones) ; COPY(sec_tens) ; COPY(min_ones) ;
 82		COPY(min_tens) ; COPY(hr_ones) ; COPY(hr_tens) ;
 83		COPY(weekday) ; COPY(day_ones) ; COPY(day_tens) ;
 84		COPY(mon_ones) ; COPY(mon_tens) ; COPY(year_ones) ;
 85		COPY(year_tens) ;
 86	/* prevent from writing the clock while it changed */
 87	} while (val->sec_ones != (mste_rtc.sec_ones & 0xf));
 88#undef COPY
 89}
 90
 91#define	RTC_READ(reg)				\
 92    ({	unsigned char	__val;			\
 93		(void) atari_writeb(reg,&tt_rtc.regsel);	\
 94		__val = tt_rtc.data;		\
 95		__val;				\
 96	})
 97
 98#define	RTC_WRITE(reg,val)			\
 99    do {					\
100		atari_writeb(reg,&tt_rtc.regsel);	\
101		tt_rtc.data = (val);		\
102	} while(0)
103
104
105#define HWCLK_POLL_INTERVAL	5
106
107int atari_mste_hwclk( int op, struct rtc_time *t )
108{
109    int hour, year;
110    int hr24=0;
111    struct MSTE_RTC val;
112
113    mste_rtc.mode=(mste_rtc.mode | 1);
114    hr24=mste_rtc.mon_tens & 1;
115    mste_rtc.mode=(mste_rtc.mode & ~1);
116
117    if (op) {
118        /* write: prepare values */
119
120        val.sec_ones = t->tm_sec % 10;
121        val.sec_tens = t->tm_sec / 10;
122        val.min_ones = t->tm_min % 10;
123        val.min_tens = t->tm_min / 10;
124        hour = t->tm_hour;
125        if (!hr24) {
126	    if (hour > 11)
127		hour += 20 - 12;
128	    if (hour == 0 || hour == 20)
129		hour += 12;
130        }
131        val.hr_ones = hour % 10;
132        val.hr_tens = hour / 10;
133        val.day_ones = t->tm_mday % 10;
134        val.day_tens = t->tm_mday / 10;
135        val.mon_ones = (t->tm_mon+1) % 10;
136        val.mon_tens = (t->tm_mon+1) / 10;
137        year = t->tm_year - 80;
138        val.year_ones = year % 10;
139        val.year_tens = year / 10;
140        val.weekday = t->tm_wday;
141        mste_write(&val);
142        mste_rtc.mode=(mste_rtc.mode | 1);
143        val.year_ones = (year % 4);	/* leap year register */
144        mste_rtc.mode=(mste_rtc.mode & ~1);
145    }
146    else {
147        mste_read(&val);
148        t->tm_sec = val.sec_ones + val.sec_tens * 10;
149        t->tm_min = val.min_ones + val.min_tens * 10;
150        hour = val.hr_ones + val.hr_tens * 10;
151	if (!hr24) {
152	    if (hour == 12 || hour == 12 + 20)
153		hour -= 12;
154	    if (hour >= 20)
155                hour += 12 - 20;
156        }
157	t->tm_hour = hour;
158	t->tm_mday = val.day_ones + val.day_tens * 10;
159        t->tm_mon  = val.mon_ones + val.mon_tens * 10 - 1;
160        t->tm_year = val.year_ones + val.year_tens * 10 + 80;
161        t->tm_wday = val.weekday;
162    }
163    return 0;
164}
165
166int atari_tt_hwclk( int op, struct rtc_time *t )
167{
168    int sec=0, min=0, hour=0, day=0, mon=0, year=0, wday=0;
169    unsigned long	flags;
170    unsigned char	ctrl;
171    int pm = 0;
172
173    ctrl = RTC_READ(RTC_CONTROL); /* control registers are
174                                   * independent from the UIP */
175
176    if (op) {
177        /* write: prepare values */
178
179        sec  = t->tm_sec;
180        min  = t->tm_min;
181        hour = t->tm_hour;
182        day  = t->tm_mday;
183        mon  = t->tm_mon + 1;
184        year = t->tm_year - atari_rtc_year_offset;
185        wday = t->tm_wday + (t->tm_wday >= 0);
186
187        if (!(ctrl & RTC_24H)) {
188	    if (hour > 11) {
189		pm = 0x80;
190		if (hour != 12)
191		    hour -= 12;
192	    }
193	    else if (hour == 0)
194		hour = 12;
195        }
196
197        if (!(ctrl & RTC_DM_BINARY)) {
198	    sec = bin2bcd(sec);
199	    min = bin2bcd(min);
200	    hour = bin2bcd(hour);
201	    day = bin2bcd(day);
202	    mon = bin2bcd(mon);
203	    year = bin2bcd(year);
204	    if (wday >= 0)
205		wday = bin2bcd(wday);
206        }
207    }
208
209    /* Reading/writing the clock registers is a bit critical due to
210     * the regular update cycle of the RTC. While an update is in
211     * progress, registers 0..9 shouldn't be touched.
212     * The problem is solved like that: If an update is currently in
213     * progress (the UIP bit is set), the process sleeps for a while
214     * (50ms). This really should be enough, since the update cycle
215     * normally needs 2 ms.
216     * If the UIP bit reads as 0, we have at least 244 usecs until the
217     * update starts. This should be enough... But to be sure,
218     * additionally the RTC_SET bit is set to prevent an update cycle.
219     */
220
221    while( RTC_READ(RTC_FREQ_SELECT) & RTC_UIP ) {
222	if (in_atomic() || irqs_disabled())
223	    mdelay(1);
224	else
225	    schedule_timeout_interruptible(HWCLK_POLL_INTERVAL);
226    }
227
228    local_irq_save(flags);
229    RTC_WRITE( RTC_CONTROL, ctrl | RTC_SET );
230    if (!op) {
231        sec  = RTC_READ( RTC_SECONDS );
232        min  = RTC_READ( RTC_MINUTES );
233        hour = RTC_READ( RTC_HOURS );
234        day  = RTC_READ( RTC_DAY_OF_MONTH );
235        mon  = RTC_READ( RTC_MONTH );
236        year = RTC_READ( RTC_YEAR );
237        wday = RTC_READ( RTC_DAY_OF_WEEK );
238    }
239    else {
240        RTC_WRITE( RTC_SECONDS, sec );
241        RTC_WRITE( RTC_MINUTES, min );
242        RTC_WRITE( RTC_HOURS, hour + pm);
243        RTC_WRITE( RTC_DAY_OF_MONTH, day );
244        RTC_WRITE( RTC_MONTH, mon );
245        RTC_WRITE( RTC_YEAR, year );
246        if (wday >= 0) RTC_WRITE( RTC_DAY_OF_WEEK, wday );
247    }
248    RTC_WRITE( RTC_CONTROL, ctrl & ~RTC_SET );
249    local_irq_restore(flags);
250
251    if (!op) {
252        /* read: adjust values */
253
254        if (hour & 0x80) {
255	    hour &= ~0x80;
256	    pm = 1;
257	}
258
259	if (!(ctrl & RTC_DM_BINARY)) {
260	    sec = bcd2bin(sec);
261	    min = bcd2bin(min);
262	    hour = bcd2bin(hour);
263	    day = bcd2bin(day);
264	    mon = bcd2bin(mon);
265	    year = bcd2bin(year);
266	    wday = bcd2bin(wday);
267        }
268
269        if (!(ctrl & RTC_24H)) {
270	    if (!pm && hour == 12)
271		hour = 0;
272	    else if (pm && hour != 12)
273		hour += 12;
274        }
275
276        t->tm_sec  = sec;
277        t->tm_min  = min;
278        t->tm_hour = hour;
279        t->tm_mday = day;
280        t->tm_mon  = mon - 1;
281        t->tm_year = year + atari_rtc_year_offset;
282        t->tm_wday = wday - 1;
283    }
284
285    return( 0 );
286}
287
288
289int atari_mste_set_clock_mmss (unsigned long nowtime)
290{
291    short real_seconds = nowtime % 60, real_minutes = (nowtime / 60) % 60;
292    struct MSTE_RTC val;
293    unsigned char rtc_minutes;
294
295    mste_read(&val);
296    rtc_minutes= val.min_ones + val.min_tens * 10;
297    if ((rtc_minutes < real_minutes
298         ? real_minutes - rtc_minutes
299         : rtc_minutes - real_minutes) < 30)
300    {
301        val.sec_ones = real_seconds % 10;
302        val.sec_tens = real_seconds / 10;
303        val.min_ones = real_minutes % 10;
304        val.min_tens = real_minutes / 10;
305        mste_write(&val);
306    }
307    else
308        return -1;
309    return 0;
310}
311
312int atari_tt_set_clock_mmss (unsigned long nowtime)
313{
314    int retval = 0;
315    short real_seconds = nowtime % 60, real_minutes = (nowtime / 60) % 60;
316    unsigned char save_control, save_freq_select, rtc_minutes;
317
318    save_control = RTC_READ (RTC_CONTROL); /* tell the clock it's being set */
319    RTC_WRITE (RTC_CONTROL, save_control | RTC_SET);
320
321    save_freq_select = RTC_READ (RTC_FREQ_SELECT); /* stop and reset prescaler */
322    RTC_WRITE (RTC_FREQ_SELECT, save_freq_select | RTC_DIV_RESET2);
323
324    rtc_minutes = RTC_READ (RTC_MINUTES);
325    if (!(save_control & RTC_DM_BINARY))
326	rtc_minutes = bcd2bin(rtc_minutes);
327
328    /* Since we're only adjusting minutes and seconds, don't interfere
329       with hour overflow.  This avoids messing with unknown time zones
330       but requires your RTC not to be off by more than 30 minutes.  */
331    if ((rtc_minutes < real_minutes
332         ? real_minutes - rtc_minutes
333         : rtc_minutes - real_minutes) < 30)
334        {
335            if (!(save_control & RTC_DM_BINARY))
336                {
337		    real_seconds = bin2bcd(real_seconds);
338		    real_minutes = bin2bcd(real_minutes);
339                }
340            RTC_WRITE (RTC_SECONDS, real_seconds);
341            RTC_WRITE (RTC_MINUTES, real_minutes);
342        }
343    else
344        retval = -1;
345
346    RTC_WRITE (RTC_FREQ_SELECT, save_freq_select);
347    RTC_WRITE (RTC_CONTROL, save_control);
348    return retval;
349}
350
351/*
352 * Local variables:
353 *  c-indent-level: 4
354 *  tab-width: 8
355 * End:
356 */