1 /* 2 * Support for periodic interrupts (100 per second) and for getting 3 * the current time from the RTC on Power Macintoshes. 4 * 5 * We use the decrementer register for our periodic interrupts. 6 * 7 * Paul Mackerras August 1996. 8 * Copyright (C) 1996 Paul Mackerras. 9 * Copyright (C) 2003-2005 Benjamin Herrenschmidt. 10 * 11 */ 12 #include <linux/config.h> 13 #include <linux/errno.h> 14 #include <linux/sched.h> 15 #include <linux/kernel.h> 16 #include <linux/param.h> 17 #include <linux/string.h> 18 #include <linux/mm.h> 19 #include <linux/init.h> 20 #include <linux/time.h> 21 #include <linux/adb.h> 22 #include <linux/cuda.h> 23 #include <linux/pmu.h> 24 #include <linux/interrupt.h> 25 #include <linux/hardirq.h> 26 #include <linux/rtc.h> 27 28 #include <asm/sections.h> 29 #include <asm/prom.h> 30 #include <asm/system.h> 31 #include <asm/io.h> 32 #include <asm/pgtable.h> 33 #include <asm/machdep.h> 34 #include <asm/time.h> 35 #include <asm/nvram.h> 36 #include <asm/smu.h> 37 38 #undef DEBUG 39 40 #ifdef DEBUG 41 #define DBG(x...) printk(x) 42 #else 43 #define DBG(x...) 44 #endif 45 46 /* Apparently the RTC stores seconds since 1 Jan 1904 */ 47 #define RTC_OFFSET 2082844800 48 49 /* 50 * Calibrate the decrementer frequency with the VIA timer 1. 51 */ 52 #define VIA_TIMER_FREQ_6 4700000 /* time 1 frequency * 6 */ 53 54 /* VIA registers */ 55 #define RS 0x200 /* skip between registers */ 56 #define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */ 57 #define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */ 58 #define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */ 59 #define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */ 60 #define ACR (11*RS) /* Auxiliary control register */ 61 #define IFR (13*RS) /* Interrupt flag register */ 62 63 /* Bits in ACR */ 64 #define T1MODE 0xc0 /* Timer 1 mode */ 65 #define T1MODE_CONT 0x40 /* continuous interrupts */ 66 67 /* Bits in IFR and IER */ 68 #define T1_INT 0x40 /* Timer 1 interrupt */ 69 70 long __init pmac_time_init(void) 71 { 72 s32 delta = 0; 73 #ifdef CONFIG_NVRAM 74 int dst; 75 76 delta = ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x9)) << 16; 77 delta |= ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xa)) << 8; 78 delta |= pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xb); 79 if (delta & 0x00800000UL) 80 delta |= 0xFF000000UL; 81 dst = ((pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x8) & 0x80) != 0); 82 printk("GMT Delta read from XPRAM: %d minutes, DST: %s\n", delta/60, 83 dst ? "on" : "off"); 84 #endif 85 return delta; 86 } 87 88 static void to_rtc_time(unsigned long now, struct rtc_time *tm) 89 { 90 to_tm(now, tm); 91 tm->tm_year -= 1900; 92 tm->tm_mon -= 1; 93 } 94 95 static unsigned long from_rtc_time(struct rtc_time *tm) 96 { 97 return mktime(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday, 98 tm->tm_hour, tm->tm_min, tm->tm_sec); 99 } 100 101 #ifdef CONFIG_ADB_CUDA 102 static unsigned long cuda_get_time(void) 103 { 104 struct adb_request req; 105 unsigned long now; 106 107 if (cuda_request(&req, NULL, 2, CUDA_PACKET, CUDA_GET_TIME) < 0) 108 return 0; 109 while (!req.complete) 110 cuda_poll(); 111 if (req.reply_len != 7) 112 printk(KERN_ERR "cuda_get_time: got %d byte reply\n", 113 req.reply_len); 114 now = (req.reply[3] << 24) + (req.reply[4] << 16) 115 + (req.reply[5] << 8) + req.reply[6]; 116 if (now < RTC_OFFSET) 117 return 0; 118 return now - RTC_OFFSET; 119 } 120 121 #define cuda_get_rtc_time(tm) to_rtc_time(cuda_get_time(), (tm)) 122 123 static int cuda_set_rtc_time(struct rtc_time *tm) 124 { 125 unsigned int nowtime; 126 struct adb_request req; 127 128 nowtime = from_rtc_time(tm) + RTC_OFFSET; 129 if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME, 130 nowtime >> 24, nowtime >> 16, nowtime >> 8, 131 nowtime) < 0) 132 return -ENXIO; 133 while (!req.complete) 134 cuda_poll(); 135 if ((req.reply_len != 3) && (req.reply_len != 7)) 136 printk(KERN_ERR "cuda_set_rtc_time: got %d byte reply\n", 137 req.reply_len); 138 return 0; 139 } 140 141 #else 142 #define cuda_get_time() 0 143 #define cuda_get_rtc_time(tm) 144 #define cuda_set_rtc_time(tm) 0 145 #endif 146 147 #ifdef CONFIG_ADB_PMU 148 static unsigned long pmu_get_time(void) 149 { 150 struct adb_request req; 151 unsigned long now; 152 153 if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0) 154 return 0; 155 pmu_wait_complete(&req); 156 if (req.reply_len != 4) 157 printk(KERN_ERR "pmu_get_time: got %d byte reply from PMU\n", 158 req.reply_len); 159 now = (req.reply[0] << 24) + (req.reply[1] << 16) 160 + (req.reply[2] << 8) + req.reply[3]; 161 if (now < RTC_OFFSET) 162 return 0; 163 return now - RTC_OFFSET; 164 } 165 166 #define pmu_get_rtc_time(tm) to_rtc_time(pmu_get_time(), (tm)) 167 168 static int pmu_set_rtc_time(struct rtc_time *tm) 169 { 170 unsigned int nowtime; 171 struct adb_request req; 172 173 nowtime = from_rtc_time(tm) + RTC_OFFSET; 174 if (pmu_request(&req, NULL, 5, PMU_SET_RTC, nowtime >> 24, 175 nowtime >> 16, nowtime >> 8, nowtime) < 0) 176 return -ENXIO; 177 pmu_wait_complete(&req); 178 if (req.reply_len != 0) 179 printk(KERN_ERR "pmu_set_rtc_time: %d byte reply from PMU\n", 180 req.reply_len); 181 return 0; 182 } 183 184 #else 185 #define pmu_get_time() 0 186 #define pmu_get_rtc_time(tm) 187 #define pmu_set_rtc_time(tm) 0 188 #endif 189 190 #ifdef CONFIG_PMAC_SMU 191 static unsigned long smu_get_time(void) 192 { 193 struct rtc_time tm; 194 195 if (smu_get_rtc_time(&tm, 1)) 196 return 0; 197 return from_rtc_time(&tm); 198 } 199 200 #else 201 #define smu_get_time() 0 202 #define smu_get_rtc_time(tm, spin) 203 #define smu_set_rtc_time(tm, spin) 0 204 #endif 205 206 unsigned long pmac_get_boot_time(void) 207 { 208 /* Get the time from the RTC, used only at boot time */ 209 switch (sys_ctrler) { 210 case SYS_CTRLER_CUDA: 211 return cuda_get_time(); 212 case SYS_CTRLER_PMU: 213 return pmu_get_time(); 214 case SYS_CTRLER_SMU: 215 return smu_get_time(); 216 default: 217 return 0; 218 } 219 } 220 221 void pmac_get_rtc_time(struct rtc_time *tm) 222 { 223 /* Get the time from the RTC, used only at boot time */ 224 switch (sys_ctrler) { 225 case SYS_CTRLER_CUDA: 226 cuda_get_rtc_time(tm); 227 break; 228 case SYS_CTRLER_PMU: 229 pmu_get_rtc_time(tm); 230 break; 231 case SYS_CTRLER_SMU: 232 smu_get_rtc_time(tm, 1); 233 break; 234 default: 235 ; 236 } 237 } 238 239 int pmac_set_rtc_time(struct rtc_time *tm) 240 { 241 switch (sys_ctrler) { 242 case SYS_CTRLER_CUDA: 243 return cuda_set_rtc_time(tm); 244 case SYS_CTRLER_PMU: 245 return pmu_set_rtc_time(tm); 246 case SYS_CTRLER_SMU: 247 return smu_set_rtc_time(tm, 1); 248 default: 249 return -ENODEV; 250 } 251 } 252 253 #ifdef CONFIG_PPC32 254 /* 255 * Calibrate the decrementer register using VIA timer 1. 256 * This is used both on powermacs and CHRP machines. 257 */ 258 int __init via_calibrate_decr(void) 259 { 260 struct device_node *vias; 261 volatile unsigned char __iomem *via; 262 int count = VIA_TIMER_FREQ_6 / 100; 263 unsigned int dstart, dend; 264 265 vias = find_devices("via-cuda"); 266 if (vias == 0) 267 vias = find_devices("via-pmu"); 268 if (vias == 0) 269 vias = find_devices("via"); 270 if (vias == 0 || vias->n_addrs == 0) 271 return 0; 272 via = ioremap(vias->addrs[0].address, vias->addrs[0].size); 273 274 /* set timer 1 for continuous interrupts */ 275 out_8(&via[ACR], (via[ACR] & ~T1MODE) | T1MODE_CONT); 276 /* set the counter to a small value */ 277 out_8(&via[T1CH], 2); 278 /* set the latch to `count' */ 279 out_8(&via[T1LL], count); 280 out_8(&via[T1LH], count >> 8); 281 /* wait until it hits 0 */ 282 while ((in_8(&via[IFR]) & T1_INT) == 0) 283 ; 284 dstart = get_dec(); 285 /* clear the interrupt & wait until it hits 0 again */ 286 in_8(&via[T1CL]); 287 while ((in_8(&via[IFR]) & T1_INT) == 0) 288 ; 289 dend = get_dec(); 290 291 ppc_tb_freq = (dstart - dend) * 100 / 6; 292 293 iounmap(via); 294 295 return 1; 296 } 297 #endif 298 299 #ifdef CONFIG_PM 300 /* 301 * Reset the time after a sleep. 302 */ 303 static int 304 time_sleep_notify(struct pmu_sleep_notifier *self, int when) 305 { 306 static unsigned long time_diff; 307 unsigned long flags; 308 unsigned long seq; 309 struct timespec tv; 310 311 switch (when) { 312 case PBOOK_SLEEP_NOW: 313 do { 314 seq = read_seqbegin_irqsave(&xtime_lock, flags); 315 time_diff = xtime.tv_sec - pmac_get_boot_time(); 316 } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); 317 break; 318 case PBOOK_WAKE: 319 tv.tv_sec = pmac_get_boot_time() + time_diff; 320 tv.tv_nsec = 0; 321 do_settimeofday(&tv); 322 break; 323 } 324 return PBOOK_SLEEP_OK; 325 } 326 327 static struct pmu_sleep_notifier time_sleep_notifier = { 328 time_sleep_notify, SLEEP_LEVEL_MISC, 329 }; 330 #endif /* CONFIG_PM */ 331 332 /* 333 * Query the OF and get the decr frequency. 334 */ 335 void __init pmac_calibrate_decr(void) 336 { 337 #ifdef CONFIG_PM 338 /* XXX why here? */ 339 pmu_register_sleep_notifier(&time_sleep_notifier); 340 #endif /* CONFIG_PM */ 341 342 generic_calibrate_decr(); 343 344 #ifdef CONFIG_PPC32 345 /* We assume MacRISC2 machines have correct device-tree 346 * calibration. That's better since the VIA itself seems 347 * to be slightly off. --BenH 348 */ 349 if (!machine_is_compatible("MacRISC2") && 350 !machine_is_compatible("MacRISC3") && 351 !machine_is_compatible("MacRISC4")) 352 if (via_calibrate_decr()) 353 return; 354 355 /* Special case: QuickSilver G4s seem to have a badly calibrated 356 * timebase-frequency in OF, VIA is much better on these. We should 357 * probably implement calibration based on the KL timer on these 358 * machines anyway... -BenH 359 */ 360 if (machine_is_compatible("PowerMac3,5")) 361 if (via_calibrate_decr()) 362 return; 363 #endif 364 } 365