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 int 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 return ((unsigned long)now) - RTC_OFFSET; 117 } 118 119 #define cuda_get_rtc_time(tm) to_rtc_time(cuda_get_time(), (tm)) 120 121 static int cuda_set_rtc_time(struct rtc_time *tm) 122 { 123 unsigned int nowtime; 124 struct adb_request req; 125 126 nowtime = from_rtc_time(tm) + RTC_OFFSET; 127 if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME, 128 nowtime >> 24, nowtime >> 16, nowtime >> 8, 129 nowtime) < 0) 130 return -ENXIO; 131 while (!req.complete) 132 cuda_poll(); 133 if ((req.reply_len != 3) && (req.reply_len != 7)) 134 printk(KERN_ERR "cuda_set_rtc_time: got %d byte reply\n", 135 req.reply_len); 136 return 0; 137 } 138 139 #else 140 #define cuda_get_time() 0 141 #define cuda_get_rtc_time(tm) 142 #define cuda_set_rtc_time(tm) 0 143 #endif 144 145 #ifdef CONFIG_ADB_PMU 146 static unsigned long pmu_get_time(void) 147 { 148 struct adb_request req; 149 unsigned int now; 150 151 if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0) 152 return 0; 153 pmu_wait_complete(&req); 154 if (req.reply_len != 4) 155 printk(KERN_ERR "pmu_get_time: got %d byte reply from PMU\n", 156 req.reply_len); 157 now = (req.reply[0] << 24) + (req.reply[1] << 16) 158 + (req.reply[2] << 8) + req.reply[3]; 159 return ((unsigned long)now) - RTC_OFFSET; 160 } 161 162 #define pmu_get_rtc_time(tm) to_rtc_time(pmu_get_time(), (tm)) 163 164 static int pmu_set_rtc_time(struct rtc_time *tm) 165 { 166 unsigned int nowtime; 167 struct adb_request req; 168 169 nowtime = from_rtc_time(tm) + RTC_OFFSET; 170 if (pmu_request(&req, NULL, 5, PMU_SET_RTC, nowtime >> 24, 171 nowtime >> 16, nowtime >> 8, nowtime) < 0) 172 return -ENXIO; 173 pmu_wait_complete(&req); 174 if (req.reply_len != 0) 175 printk(KERN_ERR "pmu_set_rtc_time: %d byte reply from PMU\n", 176 req.reply_len); 177 return 0; 178 } 179 180 #else 181 #define pmu_get_time() 0 182 #define pmu_get_rtc_time(tm) 183 #define pmu_set_rtc_time(tm) 0 184 #endif 185 186 #ifdef CONFIG_PMAC_SMU 187 static unsigned long smu_get_time(void) 188 { 189 struct rtc_time tm; 190 191 if (smu_get_rtc_time(&tm, 1)) 192 return 0; 193 return from_rtc_time(&tm); 194 } 195 196 #else 197 #define smu_get_time() 0 198 #define smu_get_rtc_time(tm, spin) 199 #define smu_set_rtc_time(tm, spin) 0 200 #endif 201 202 /* Can't be __init, it's called when suspending and resuming */ 203 unsigned long pmac_get_boot_time(void) 204 { 205 /* Get the time from the RTC, used only at boot time */ 206 switch (sys_ctrler) { 207 case SYS_CTRLER_CUDA: 208 return cuda_get_time(); 209 case SYS_CTRLER_PMU: 210 return pmu_get_time(); 211 case SYS_CTRLER_SMU: 212 return smu_get_time(); 213 default: 214 return 0; 215 } 216 } 217 218 void pmac_get_rtc_time(struct rtc_time *tm) 219 { 220 /* Get the time from the RTC, used only at boot time */ 221 switch (sys_ctrler) { 222 case SYS_CTRLER_CUDA: 223 cuda_get_rtc_time(tm); 224 break; 225 case SYS_CTRLER_PMU: 226 pmu_get_rtc_time(tm); 227 break; 228 case SYS_CTRLER_SMU: 229 smu_get_rtc_time(tm, 1); 230 break; 231 default: 232 ; 233 } 234 } 235 236 int pmac_set_rtc_time(struct rtc_time *tm) 237 { 238 switch (sys_ctrler) { 239 case SYS_CTRLER_CUDA: 240 return cuda_set_rtc_time(tm); 241 case SYS_CTRLER_PMU: 242 return pmu_set_rtc_time(tm); 243 case SYS_CTRLER_SMU: 244 return smu_set_rtc_time(tm, 1); 245 default: 246 return -ENODEV; 247 } 248 } 249 250 #ifdef CONFIG_PPC32 251 /* 252 * Calibrate the decrementer register using VIA timer 1. 253 * This is used both on powermacs and CHRP machines. 254 */ 255 int __init via_calibrate_decr(void) 256 { 257 struct device_node *vias; 258 volatile unsigned char __iomem *via; 259 int count = VIA_TIMER_FREQ_6 / 100; 260 unsigned int dstart, dend; 261 262 vias = find_devices("via-cuda"); 263 if (vias == 0) 264 vias = find_devices("via-pmu"); 265 if (vias == 0) 266 vias = find_devices("via"); 267 if (vias == 0 || vias->n_addrs == 0) 268 return 0; 269 via = ioremap(vias->addrs[0].address, vias->addrs[0].size); 270 271 /* set timer 1 for continuous interrupts */ 272 out_8(&via[ACR], (via[ACR] & ~T1MODE) | T1MODE_CONT); 273 /* set the counter to a small value */ 274 out_8(&via[T1CH], 2); 275 /* set the latch to `count' */ 276 out_8(&via[T1LL], count); 277 out_8(&via[T1LH], count >> 8); 278 /* wait until it hits 0 */ 279 while ((in_8(&via[IFR]) & T1_INT) == 0) 280 ; 281 dstart = get_dec(); 282 /* clear the interrupt & wait until it hits 0 again */ 283 in_8(&via[T1CL]); 284 while ((in_8(&via[IFR]) & T1_INT) == 0) 285 ; 286 dend = get_dec(); 287 288 ppc_tb_freq = (dstart - dend) * 100 / 6; 289 290 iounmap(via); 291 292 return 1; 293 } 294 #endif 295 296 #ifdef CONFIG_PM 297 /* 298 * Reset the time after a sleep. 299 */ 300 static int 301 time_sleep_notify(struct pmu_sleep_notifier *self, int when) 302 { 303 static unsigned long time_diff; 304 unsigned long flags; 305 unsigned long seq; 306 struct timespec tv; 307 308 switch (when) { 309 case PBOOK_SLEEP_NOW: 310 do { 311 seq = read_seqbegin_irqsave(&xtime_lock, flags); 312 time_diff = xtime.tv_sec - pmac_get_boot_time(); 313 } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); 314 break; 315 case PBOOK_WAKE: 316 tv.tv_sec = pmac_get_boot_time() + time_diff; 317 tv.tv_nsec = 0; 318 do_settimeofday(&tv); 319 break; 320 } 321 return PBOOK_SLEEP_OK; 322 } 323 324 static struct pmu_sleep_notifier time_sleep_notifier = { 325 time_sleep_notify, SLEEP_LEVEL_MISC, 326 }; 327 #endif /* CONFIG_PM */ 328 329 /* 330 * Query the OF and get the decr frequency. 331 */ 332 void __init pmac_calibrate_decr(void) 333 { 334 #ifdef CONFIG_PM 335 /* XXX why here? */ 336 pmu_register_sleep_notifier(&time_sleep_notifier); 337 #endif /* CONFIG_PM */ 338 339 generic_calibrate_decr(); 340 341 #ifdef CONFIG_PPC32 342 /* We assume MacRISC2 machines have correct device-tree 343 * calibration. That's better since the VIA itself seems 344 * to be slightly off. --BenH 345 */ 346 if (!machine_is_compatible("MacRISC2") && 347 !machine_is_compatible("MacRISC3") && 348 !machine_is_compatible("MacRISC4")) 349 if (via_calibrate_decr()) 350 return; 351 352 /* Special case: QuickSilver G4s seem to have a badly calibrated 353 * timebase-frequency in OF, VIA is much better on these. We should 354 * probably implement calibration based on the KL timer on these 355 * machines anyway... -BenH 356 */ 357 if (machine_is_compatible("PowerMac3,5")) 358 if (via_calibrate_decr()) 359 return; 360 #endif 361 } 362