arch/powerpc/platforms/powermac/time.c

   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         struct resource rsrc;
 262
 263         vias = of_find_node_by_name(NULL, "via-cuda");
 264         if (vias == 0)
 265                 vias = of_find_node_by_name(NULL, "via-pmu");
 266         if (vias == 0)
 267                 vias = of_find_node_by_name(NULL, "via");
 268         if (vias == 0 || of_address_to_resource(vias, 0, &rsrc))
 269                 return 0;
 270         via = ioremap(rsrc.start, rsrc.end - rsrc.start + 1);
 271         if (via == NULL) {
 272                 printk(KERN_ERR "Failed to map VIA for timer calibration !\n");
 273                 return 0;
 274         }
 275
 276         /* set timer 1 for continuous interrupts */
 277         out_8(&via[ACR], (via[ACR] & ~T1MODE) | T1MODE_CONT);
 278         /* set the counter to a small value */
 279         out_8(&via[T1CH], 2);
 280         /* set the latch to `count' */
 281         out_8(&via[T1LL], count);
 282         out_8(&via[T1LH], count >> 8);
 283         /* wait until it hits 0 */
 284         while ((in_8(&via[IFR]) & T1_INT) == 0)
 285                 ;
 286         dstart = get_dec();
 287         /* clear the interrupt & wait until it hits 0 again */
 288         in_8(&via[T1CL]);
 289         while ((in_8(&via[IFR]) & T1_INT) == 0)
 290                 ;
 291         dend = get_dec();
 292
 293         ppc_tb_freq = (dstart - dend) * 100 / 6;
 294
 295         iounmap(via);
 296
 297         return 1;
 298 }
 299 #endif
 300
 301 #ifdef CONFIG_PM
 302 /*
 303  * Reset the time after a sleep.
 304  */
 305 static int
 306 time_sleep_notify(struct pmu_sleep_notifier *self, int when)
 307 {
 308         static unsigned long time_diff;
 309         unsigned long flags;
 310         unsigned long seq;
 311         struct timespec tv;
 312
 313         switch (when) {
 314         case PBOOK_SLEEP_NOW:
 315                 do {
 316                         seq = read_seqbegin_irqsave(&xtime_lock, flags);
 317                         time_diff = xtime.tv_sec - pmac_get_boot_time();
 318                 } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
 319                 break;
 320         case PBOOK_WAKE:
 321                 tv.tv_sec = pmac_get_boot_time() + time_diff;
 322                 tv.tv_nsec = 0;
 323                 do_settimeofday(&tv);
 324                 break;
 325         }
 326         return PBOOK_SLEEP_OK;
 327 }
 328
 329 static struct pmu_sleep_notifier time_sleep_notifier = {
 330         time_sleep_notify, SLEEP_LEVEL_MISC,
 331 };
 332 #endif /* CONFIG_PM */
 333
 334 /*
 335  * Query the OF and get the decr frequency.
 336  */
 337 void __init pmac_calibrate_decr(void)
 338 {
 339 #ifdef CONFIG_PM
 340         /* XXX why here? */
 341         pmu_register_sleep_notifier(&time_sleep_notifier);
 342 #endif /* CONFIG_PM */
 343
 344         generic_calibrate_decr();
 345
 346 #ifdef CONFIG_PPC32
 347         /* We assume MacRISC2 machines have correct device-tree
 348          * calibration. That's better since the VIA itself seems
 349          * to be slightly off. --BenH
 350          */
 351         if (!machine_is_compatible("MacRISC2") &&
 352             !machine_is_compatible("MacRISC3") &&
 353             !machine_is_compatible("MacRISC4"))
 354                 if (via_calibrate_decr())
 355                         return;
 356
 357         /* Special case: QuickSilver G4s seem to have a badly calibrated
 358          * timebase-frequency in OF, VIA is much better on these. We should
 359          * probably implement calibration based on the KL timer on these
 360          * machines anyway... -BenH
 361          */
 362         if (machine_is_compatible("PowerMac3,5"))
 363                 if (via_calibrate_decr())
 364                         return;
 365 #endif
 366 }