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