arch/m68k/atari/time.c

   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
  24 DEFINE_SPINLOCK(rtc_lock);
  25 EXPORT_SYMBOL_GPL(rtc_lock);
  26
  27 void __init
  28 atari_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.  */
  44 u32 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
  63 static 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
  77 static 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
 107 int 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
 166 int 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 /*
 289  * Local variables:
 290  *  c-indent-level: 4
 291  *  tab-width: 8
 292  * End:
 293  */