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 21#include <asm/atariints.h> 22 23DEFINE_SPINLOCK(rtc_lock); 24EXPORT_SYMBOL_GPL(rtc_lock); 25 26void __init 27atari_sched_init(irq_handler_t timer_routine) 28{ 29 /* set Timer C data Register */ 30 st_mfp.tim_dt_c = INT_TICKS; 31 /* start timer C, div = 1:100 */ 32 st_mfp.tim_ct_cd = (st_mfp.tim_ct_cd & 15) | 0x60; 33 /* install interrupt service routine for MFP Timer C */ 34 if (request_irq(IRQ_MFP_TIMC, timer_routine, IRQ_TYPE_SLOW, 35 "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. */ 44unsigned long atari_gettimeoffset (void) 45{ 46 unsigned long 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; 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 */ 357