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