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/errno.h> 13 #include <linux/sched.h> 14 #include <linux/kernel.h> 15 #include <linux/param.h> 16 #include <linux/string.h> 17 #include <linux/mm.h> 18 #include <linux/init.h> 19 #include <linux/time.h> 20 #include <linux/adb.h> 21 #include <linux/cuda.h> 22 #include <linux/pmu.h> 23 #include <linux/interrupt.h> 24 #include <linux/hardirq.h> 25 #include <linux/rtc.h> 26 27 #include <asm/sections.h> 28 #include <asm/prom.h> 29 #include <asm/system.h> 30 #include <asm/io.h> 31 #include <asm/pgtable.h> 32 #include <asm/machdep.h> 33 #include <asm/time.h> 34 #include <asm/nvram.h> 35 #include <asm/smu.h> 36 37 #undef DEBUG 38 39 #ifdef DEBUG 40 #define DBG(x...) printk(x) 41 #else 42 #define DBG(x...) 43 #endif 44 45 /* Apparently the RTC stores seconds since 1 Jan 1904 */ 46 #define RTC_OFFSET 2082844800 47 48 /* 49 * Calibrate the decrementer frequency with the VIA timer 1. 50 */ 51 #define VIA_TIMER_FREQ_6 4700000 /* time 1 frequency * 6 */ 52 53 /* VIA registers */ 54 #define RS 0x200 /* skip between registers */ 55 #define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */ 56 #define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */ 57 #define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */ 58 #define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */ 59 #define ACR (11*RS) /* Auxiliary control register */ 60 #define IFR (13*RS) /* Interrupt flag register */ 61 62 /* Bits in ACR */ 63 #define T1MODE 0xc0 /* Timer 1 mode */ 64 #define T1MODE_CONT 0x40 /* continuous interrupts */ 65 66 /* Bits in IFR and IER */ 67 #define T1_INT 0x40 /* Timer 1 interrupt */ 68 69 long __init pmac_time_init(void) 70 { 71 s32 delta = 0; 72 #ifdef CONFIG_NVRAM 73 int dst; 74 75 delta = ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x9)) << 16; 76 delta |= ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xa)) << 8; 77 delta |= pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xb); 78 if (delta & 0x00800000UL) 79 delta |= 0xFF000000UL; 80 dst = ((pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x8) & 0x80) != 0); 81 printk("GMT Delta read from XPRAM: %d minutes, DST: %s\n", delta/60, 82 dst ? "on" : "off"); 83 #endif 84 return delta; 85 } 86 87 static void to_rtc_time(unsigned long now, struct rtc_time *tm) 88 { 89 to_tm(now, tm); 90 tm->tm_year -= 1900; 91 tm->tm_mon -= 1; 92 } 93 94 static unsigned long from_rtc_time(struct rtc_time *tm) 95 { 96 return mktime(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday, 97 tm->tm_hour, tm->tm_min, tm->tm_sec); 98 } 99 100 #ifdef CONFIG_ADB_CUDA 101 static unsigned long cuda_get_time(void) 102 { 103 struct adb_request req; 104 unsigned int now; 105 106 if (cuda_request(&req, NULL, 2, CUDA_PACKET, CUDA_GET_TIME) < 0) 107 return 0; 108 while (!req.complete) 109 cuda_poll(); 110 if (req.reply_len != 7) 111 printk(KERN_ERR "cuda_get_time: got %d byte reply\n", 112 req.reply_len); 113 now = (req.reply[3] << 24) + (req.reply[4] << 16) 114 + (req.reply[5] << 8) + req.reply[6]; 115 return ((unsigned long)now) - RTC_OFFSET; 116 } 117 118 #define cuda_get_rtc_time(tm) to_rtc_time(cuda_get_time(), (tm)) 119 120 static int cuda_set_rtc_time(struct rtc_time *tm) 121 { 122 unsigned int nowtime; 123 struct adb_request req; 124 125 nowtime = from_rtc_time(tm) + RTC_OFFSET; 126 if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME, 127 nowtime >> 24, nowtime >> 16, nowtime >> 8, 128 nowtime) < 0) 129 return -ENXIO; 130 while (!req.complete) 131 cuda_poll(); 132 if ((req.reply_len != 3) && (req.reply_len != 7)) 133 printk(KERN_ERR "cuda_set_rtc_time: got %d byte reply\n", 134 req.reply_len); 135 return 0; 136 } 137 138 #else 139 #define cuda_get_time() 0 140 #define cuda_get_rtc_time(tm) 141 #define cuda_set_rtc_time(tm) 0 142 #endif 143 144 #ifdef CONFIG_ADB_PMU 145 static unsigned long pmu_get_time(void) 146 { 147 struct adb_request req; 148 unsigned int now; 149 150 if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0) 151 return 0; 152 pmu_wait_complete(&req); 153 if (req.reply_len != 4) 154 printk(KERN_ERR "pmu_get_time: got %d byte reply from PMU\n", 155 req.reply_len); 156 now = (req.reply[0] << 24) + (req.reply[1] << 16) 157 + (req.reply[2] << 8) + req.reply[3]; 158 return ((unsigned long)now) - RTC_OFFSET; 159 } 160 161 #define pmu_get_rtc_time(tm) to_rtc_time(pmu_get_time(), (tm)) 162 163 static int pmu_set_rtc_time(struct rtc_time *tm) 164 { 165 unsigned int nowtime; 166 struct adb_request req; 167 168 nowtime = from_rtc_time(tm) + RTC_OFFSET; 169 if (pmu_request(&req, NULL, 5, PMU_SET_RTC, nowtime >> 24, 170 nowtime >> 16, nowtime >> 8, nowtime) < 0) 171 return -ENXIO; 172 pmu_wait_complete(&req); 173 if (req.reply_len != 0) 174 printk(KERN_ERR "pmu_set_rtc_time: %d byte reply from PMU\n", 175 req.reply_len); 176 return 0; 177 } 178 179 #else 180 #define pmu_get_time() 0 181 #define pmu_get_rtc_time(tm) 182 #define pmu_set_rtc_time(tm) 0 183 #endif 184 185 #ifdef CONFIG_PMAC_SMU 186 static unsigned long smu_get_time(void) 187 { 188 struct rtc_time tm; 189 190 if (smu_get_rtc_time(&tm, 1)) 191 return 0; 192 return from_rtc_time(&tm); 193 } 194 195 #else 196 #define smu_get_time() 0 197 #define smu_get_rtc_time(tm, spin) 198 #define smu_set_rtc_time(tm, spin) 0 199 #endif 200 201 /* Can't be __init, it's called when suspending and resuming */ 202 unsigned long pmac_get_boot_time(void) 203 { 204 /* Get the time from the RTC, used only at boot time */ 205 switch (sys_ctrler) { 206 case SYS_CTRLER_CUDA: 207 return cuda_get_time(); 208 case SYS_CTRLER_PMU: 209 return pmu_get_time(); 210 case SYS_CTRLER_SMU: 211 return smu_get_time(); 212 default: 213 return 0; 214 } 215 } 216 217 void pmac_get_rtc_time(struct rtc_time *tm) 218 { 219 /* Get the time from the RTC, used only at boot time */ 220 switch (sys_ctrler) { 221 case SYS_CTRLER_CUDA: 222 cuda_get_rtc_time(tm); 223 break; 224 case SYS_CTRLER_PMU: 225 pmu_get_rtc_time(tm); 226 break; 227 case SYS_CTRLER_SMU: 228 smu_get_rtc_time(tm, 1); 229 break; 230 default: 231 ; 232 } 233 } 234 235 int pmac_set_rtc_time(struct rtc_time *tm) 236 { 237 switch (sys_ctrler) { 238 case SYS_CTRLER_CUDA: 239 return cuda_set_rtc_time(tm); 240 case SYS_CTRLER_PMU: 241 return pmu_set_rtc_time(tm); 242 case SYS_CTRLER_SMU: 243 return smu_set_rtc_time(tm, 1); 244 default: 245 return -ENODEV; 246 } 247 } 248 249 #ifdef CONFIG_PPC32 250 /* 251 * Calibrate the decrementer register using VIA timer 1. 252 * This is used both on powermacs and CHRP machines. 253 */ 254 int __init via_calibrate_decr(void) 255 { 256 struct device_node *vias; 257 volatile unsigned char __iomem *via; 258 int count = VIA_TIMER_FREQ_6 / 100; 259 unsigned int dstart, dend; 260 struct resource rsrc; 261 262 vias = of_find_node_by_name(NULL, "via-cuda"); 263 if (vias == 0) 264 vias = of_find_node_by_name(NULL, "via-pmu"); 265 if (vias == 0) 266 vias = of_find_node_by_name(NULL, "via"); 267 if (vias == 0 || of_address_to_resource(vias, 0, &rsrc)) 268 return 0; 269 via = ioremap(rsrc.start, rsrc.end - rsrc.start + 1); 270 if (via == NULL) { 271 printk(KERN_ERR "Failed to map VIA for timer calibration !\n"); 272 return 0; 273 } 274 275 /* set timer 1 for continuous interrupts */ 276 out_8(&via[ACR], (via[ACR] & ~T1MODE) | T1MODE_CONT); 277 /* set the counter to a small value */ 278 out_8(&via[T1CH], 2); 279 /* set the latch to `count' */ 280 out_8(&via[T1LL], count); 281 out_8(&via[T1LH], count >> 8); 282 /* wait until it hits 0 */ 283 while ((in_8(&via[IFR]) & T1_INT) == 0) 284 ; 285 dstart = get_dec(); 286 /* clear the interrupt & wait until it hits 0 again */ 287 in_8(&via[T1CL]); 288 while ((in_8(&via[IFR]) & T1_INT) == 0) 289 ; 290 dend = get_dec(); 291 292 ppc_tb_freq = (dstart - dend) * 100 / 6; 293 294 iounmap(via); 295 296 return 1; 297 } 298 #endif 299 300 #ifdef CONFIG_PM 301 /* 302 * Reset the time after a sleep. 303 */ 304 static int 305 time_sleep_notify(struct pmu_sleep_notifier *self, int when) 306 { 307 static unsigned long time_diff; 308 unsigned long flags; 309 unsigned long seq; 310 struct timespec tv; 311 312 switch (when) { 313 case PBOOK_SLEEP_NOW: 314 do { 315 seq = read_seqbegin_irqsave(&xtime_lock, flags); 316 time_diff = xtime.tv_sec - pmac_get_boot_time(); 317 } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); 318 break; 319 case PBOOK_WAKE: 320 tv.tv_sec = pmac_get_boot_time() + time_diff; 321 tv.tv_nsec = 0; 322 do_settimeofday(&tv); 323 break; 324 } 325 return PBOOK_SLEEP_OK; 326 } 327 328 static struct pmu_sleep_notifier time_sleep_notifier = { 329 time_sleep_notify, SLEEP_LEVEL_MISC, 330 }; 331 #endif /* CONFIG_PM */ 332 333 /* 334 * Query the OF and get the decr frequency. 335 */ 336 void __init pmac_calibrate_decr(void) 337 { 338 #if defined(CONFIG_PM) && defined(CONFIG_ADB_PMU) 339 /* XXX why here? */ 340 pmu_register_sleep_notifier(&time_sleep_notifier); 341 #endif 342 343 generic_calibrate_decr(); 344 345 #ifdef CONFIG_PPC32 346 /* We assume MacRISC2 machines have correct device-tree 347 * calibration. That's better since the VIA itself seems 348 * to be slightly off. --BenH 349 */ 350 if (!machine_is_compatible("MacRISC2") && 351 !machine_is_compatible("MacRISC3") && 352 !machine_is_compatible("MacRISC4")) 353 if (via_calibrate_decr()) 354 return; 355 356 /* Special case: QuickSilver G4s seem to have a badly calibrated 357 * timebase-frequency in OF, VIA is much better on these. We should 358 * probably implement calibration based on the KL timer on these 359 * machines anyway... -BenH 360 */ 361 if (machine_is_compatible("PowerMac3,5")) 362 if (via_calibrate_decr()) 363 return; 364 #endif 365 } 366