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, IRQ_TYPE_SLOW, 36 "timer", timer_routine)) 37 pr_err("Couldn't register timer interrupt\n"); 38 } 39 40 /* ++andreas: gettimeoffset fixed to check for pending interrupt */ 41 42 #define TICK_SIZE 10000 43 44 /* This is always executed with interrupts disabled. */ 45 unsigned long atari_gettimeoffset (void) 46 { 47 unsigned long ticks, offset = 0; 48 49 /* read MFP timer C current value */ 50 ticks = st_mfp.tim_dt_c; 51 /* The probability of underflow is less than 2% */ 52 if (ticks > INT_TICKS - INT_TICKS / 50) 53 /* Check for pending timer interrupt */ 54 if (st_mfp.int_pn_b & (1 << 5)) 55 offset = TICK_SIZE; 56 57 ticks = INT_TICKS - ticks; 58 ticks = ticks * 10000L / INT_TICKS; 59 60 return ticks + offset; 61 } 62 63 64 static void mste_read(struct MSTE_RTC *val) 65 { 66 #define COPY(v) val->v=(mste_rtc.v & 0xf) 67 do { 68 COPY(sec_ones) ; COPY(sec_tens) ; COPY(min_ones) ; 69 COPY(min_tens) ; COPY(hr_ones) ; COPY(hr_tens) ; 70 COPY(weekday) ; COPY(day_ones) ; COPY(day_tens) ; 71 COPY(mon_ones) ; COPY(mon_tens) ; COPY(year_ones) ; 72 COPY(year_tens) ; 73 /* prevent from reading the clock while it changed */ 74 } while (val->sec_ones != (mste_rtc.sec_ones & 0xf)); 75 #undef COPY 76 } 77 78 static void mste_write(struct MSTE_RTC *val) 79 { 80 #define COPY(v) mste_rtc.v=val->v 81 do { 82 COPY(sec_ones) ; COPY(sec_tens) ; COPY(min_ones) ; 83 COPY(min_tens) ; COPY(hr_ones) ; COPY(hr_tens) ; 84 COPY(weekday) ; COPY(day_ones) ; COPY(day_tens) ; 85 COPY(mon_ones) ; COPY(mon_tens) ; COPY(year_ones) ; 86 COPY(year_tens) ; 87 /* prevent from writing the clock while it changed */ 88 } while (val->sec_ones != (mste_rtc.sec_ones & 0xf)); 89 #undef COPY 90 } 91 92 #define RTC_READ(reg) \ 93 ({ unsigned char __val; \ 94 (void) atari_writeb(reg,&tt_rtc.regsel); \ 95 __val = tt_rtc.data; \ 96 __val; \ 97 }) 98 99 #define RTC_WRITE(reg,val) \ 100 do { \ 101 atari_writeb(reg,&tt_rtc.regsel); \ 102 tt_rtc.data = (val); \ 103 } while(0) 104 105 106 #define HWCLK_POLL_INTERVAL 5 107 108 int atari_mste_hwclk( int op, struct rtc_time *t ) 109 { 110 int hour, year; 111 int hr24=0; 112 struct MSTE_RTC val; 113 114 mste_rtc.mode=(mste_rtc.mode | 1); 115 hr24=mste_rtc.mon_tens & 1; 116 mste_rtc.mode=(mste_rtc.mode & ~1); 117 118 if (op) { 119 /* write: prepare values */ 120 121 val.sec_ones = t->tm_sec % 10; 122 val.sec_tens = t->tm_sec / 10; 123 val.min_ones = t->tm_min % 10; 124 val.min_tens = t->tm_min / 10; 125 hour = t->tm_hour; 126 if (!hr24) { 127 if (hour > 11) 128 hour += 20 - 12; 129 if (hour == 0 || hour == 20) 130 hour += 12; 131 } 132 val.hr_ones = hour % 10; 133 val.hr_tens = hour / 10; 134 val.day_ones = t->tm_mday % 10; 135 val.day_tens = t->tm_mday / 10; 136 val.mon_ones = (t->tm_mon+1) % 10; 137 val.mon_tens = (t->tm_mon+1) / 10; 138 year = t->tm_year - 80; 139 val.year_ones = year % 10; 140 val.year_tens = year / 10; 141 val.weekday = t->tm_wday; 142 mste_write(&val); 143 mste_rtc.mode=(mste_rtc.mode | 1); 144 val.year_ones = (year % 4); /* leap year register */ 145 mste_rtc.mode=(mste_rtc.mode & ~1); 146 } 147 else { 148 mste_read(&val); 149 t->tm_sec = val.sec_ones + val.sec_tens * 10; 150 t->tm_min = val.min_ones + val.min_tens * 10; 151 hour = val.hr_ones + val.hr_tens * 10; 152 if (!hr24) { 153 if (hour == 12 || hour == 12 + 20) 154 hour -= 12; 155 if (hour >= 20) 156 hour += 12 - 20; 157 } 158 t->tm_hour = hour; 159 t->tm_mday = val.day_ones + val.day_tens * 10; 160 t->tm_mon = val.mon_ones + val.mon_tens * 10 - 1; 161 t->tm_year = val.year_ones + val.year_tens * 10 + 80; 162 t->tm_wday = val.weekday; 163 } 164 return 0; 165 } 166 167 int atari_tt_hwclk( int op, struct rtc_time *t ) 168 { 169 int sec=0, min=0, hour=0, day=0, mon=0, year=0, wday=0; 170 unsigned long flags; 171 unsigned char ctrl; 172 int pm = 0; 173 174 ctrl = RTC_READ(RTC_CONTROL); /* control registers are 175 * independent from the UIP */ 176 177 if (op) { 178 /* write: prepare values */ 179 180 sec = t->tm_sec; 181 min = t->tm_min; 182 hour = t->tm_hour; 183 day = t->tm_mday; 184 mon = t->tm_mon + 1; 185 year = t->tm_year - atari_rtc_year_offset; 186 wday = t->tm_wday + (t->tm_wday >= 0); 187 188 if (!(ctrl & RTC_24H)) { 189 if (hour > 11) { 190 pm = 0x80; 191 if (hour != 12) 192 hour -= 12; 193 } 194 else if (hour == 0) 195 hour = 12; 196 } 197 198 if (!(ctrl & RTC_DM_BINARY)) { 199 sec = bin2bcd(sec); 200 min = bin2bcd(min); 201 hour = bin2bcd(hour); 202 day = bin2bcd(day); 203 mon = bin2bcd(mon); 204 year = bin2bcd(year); 205 if (wday >= 0) 206 wday = bin2bcd(wday); 207 } 208 } 209 210 /* Reading/writing the clock registers is a bit critical due to 211 * the regular update cycle of the RTC. While an update is in 212 * progress, registers 0..9 shouldn't be touched. 213 * The problem is solved like that: If an update is currently in 214 * progress (the UIP bit is set), the process sleeps for a while 215 * (50ms). This really should be enough, since the update cycle 216 * normally needs 2 ms. 217 * If the UIP bit reads as 0, we have at least 244 usecs until the 218 * update starts. This should be enough... But to be sure, 219 * additionally the RTC_SET bit is set to prevent an update cycle. 220 */ 221 222 while( RTC_READ(RTC_FREQ_SELECT) & RTC_UIP ) { 223 if (in_atomic() || irqs_disabled()) 224 mdelay(1); 225 else 226 schedule_timeout_interruptible(HWCLK_POLL_INTERVAL); 227 } 228 229 local_irq_save(flags); 230 RTC_WRITE( RTC_CONTROL, ctrl | RTC_SET ); 231 if (!op) { 232 sec = RTC_READ( RTC_SECONDS ); 233 min = RTC_READ( RTC_MINUTES ); 234 hour = RTC_READ( RTC_HOURS ); 235 day = RTC_READ( RTC_DAY_OF_MONTH ); 236 mon = RTC_READ( RTC_MONTH ); 237 year = RTC_READ( RTC_YEAR ); 238 wday = RTC_READ( RTC_DAY_OF_WEEK ); 239 } 240 else { 241 RTC_WRITE( RTC_SECONDS, sec ); 242 RTC_WRITE( RTC_MINUTES, min ); 243 RTC_WRITE( RTC_HOURS, hour + pm); 244 RTC_WRITE( RTC_DAY_OF_MONTH, day ); 245 RTC_WRITE( RTC_MONTH, mon ); 246 RTC_WRITE( RTC_YEAR, year ); 247 if (wday >= 0) RTC_WRITE( RTC_DAY_OF_WEEK, wday ); 248 } 249 RTC_WRITE( RTC_CONTROL, ctrl & ~RTC_SET ); 250 local_irq_restore(flags); 251 252 if (!op) { 253 /* read: adjust values */ 254 255 if (hour & 0x80) { 256 hour &= ~0x80; 257 pm = 1; 258 } 259 260 if (!(ctrl & RTC_DM_BINARY)) { 261 sec = bcd2bin(sec); 262 min = bcd2bin(min); 263 hour = bcd2bin(hour); 264 day = bcd2bin(day); 265 mon = bcd2bin(mon); 266 year = bcd2bin(year); 267 wday = bcd2bin(wday); 268 } 269 270 if (!(ctrl & RTC_24H)) { 271 if (!pm && hour == 12) 272 hour = 0; 273 else if (pm && hour != 12) 274 hour += 12; 275 } 276 277 t->tm_sec = sec; 278 t->tm_min = min; 279 t->tm_hour = hour; 280 t->tm_mday = day; 281 t->tm_mon = mon - 1; 282 t->tm_year = year + atari_rtc_year_offset; 283 t->tm_wday = wday - 1; 284 } 285 286 return( 0 ); 287 } 288 289 290 int atari_mste_set_clock_mmss (unsigned long nowtime) 291 { 292 short real_seconds = nowtime % 60, real_minutes = (nowtime / 60) % 60; 293 struct MSTE_RTC val; 294 unsigned char rtc_minutes; 295 296 mste_read(&val); 297 rtc_minutes= val.min_ones + val.min_tens * 10; 298 if ((rtc_minutes < real_minutes 299 ? real_minutes - rtc_minutes 300 : rtc_minutes - real_minutes) < 30) 301 { 302 val.sec_ones = real_seconds % 10; 303 val.sec_tens = real_seconds / 10; 304 val.min_ones = real_minutes % 10; 305 val.min_tens = real_minutes / 10; 306 mste_write(&val); 307 } 308 else 309 return -1; 310 return 0; 311 } 312 313 int atari_tt_set_clock_mmss (unsigned long nowtime) 314 { 315 int retval = 0; 316 short real_seconds = nowtime % 60, real_minutes = (nowtime / 60) % 60; 317 unsigned char save_control, save_freq_select, rtc_minutes; 318 319 save_control = RTC_READ (RTC_CONTROL); /* tell the clock it's being set */ 320 RTC_WRITE (RTC_CONTROL, save_control | RTC_SET); 321 322 save_freq_select = RTC_READ (RTC_FREQ_SELECT); /* stop and reset prescaler */ 323 RTC_WRITE (RTC_FREQ_SELECT, save_freq_select | RTC_DIV_RESET2); 324 325 rtc_minutes = RTC_READ (RTC_MINUTES); 326 if (!(save_control & RTC_DM_BINARY)) 327 rtc_minutes = bcd2bin(rtc_minutes); 328 329 /* Since we're only adjusting minutes and seconds, don't interfere 330 with hour overflow. This avoids messing with unknown time zones 331 but requires your RTC not to be off by more than 30 minutes. */ 332 if ((rtc_minutes < real_minutes 333 ? real_minutes - rtc_minutes 334 : rtc_minutes - real_minutes) < 30) 335 { 336 if (!(save_control & RTC_DM_BINARY)) 337 { 338 real_seconds = bin2bcd(real_seconds); 339 real_minutes = bin2bcd(real_minutes); 340 } 341 RTC_WRITE (RTC_SECONDS, real_seconds); 342 RTC_WRITE (RTC_MINUTES, real_minutes); 343 } 344 else 345 retval = -1; 346 347 RTC_WRITE (RTC_FREQ_SELECT, save_freq_select); 348 RTC_WRITE (RTC_CONTROL, save_control); 349 return retval; 350 } 351 352 /* 353 * Local variables: 354 * c-indent-level: 4 355 * tab-width: 8 356 * End: 357 */ 358