arch/sparc/kernel/time.c

   1 /* linux/arch/sparc/kernel/time.c
   2  *
   3  * Copyright (C) 1995 David S. Miller (davem@davemloft.net)
   4  * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
   5  *
   6  * Chris Davis (cdavis@cois.on.ca) 03/27/1998
   7  * Added support for the intersil on the sun4/4200
   8  *
   9  * Gleb Raiko (rajko@mech.math.msu.su) 08/18/1998
  10  * Support for MicroSPARC-IIep, PCI CPU.
  11  *
  12  * This file handles the Sparc specific time handling details.
  13  *
  14  * 1997-09-10   Updated NTP code according to technical memorandum Jan '96
  15  *              "A Kernel Model for Precision Timekeeping" by Dave Mills
  16  */
  17 #include <linux/errno.h>
  18 #include <linux/module.h>
  19 #include <linux/sched.h>
  20 #include <linux/kernel.h>
  21 #include <linux/param.h>
  22 #include <linux/string.h>
  23 #include <linux/mm.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/time.h>
  26 #include <linux/rtc.h>
  27 #include <linux/rtc/m48t59.h>
  28 #include <linux/timex.h>
  29 #include <linux/init.h>
  30 #include <linux/pci.h>
  31 #include <linux/ioport.h>
  32 #include <linux/profile.h>
  33 #include <linux/of.h>
  34 #include <linux/of_device.h>
  35 #include <linux/platform_device.h>
  36
  37 #include <asm/oplib.h>
  38 #include <asm/timer.h>
  39 #include <asm/system.h>
  40 #include <asm/irq.h>
  41 #include <asm/io.h>
  42 #include <asm/idprom.h>
  43 #include <asm/machines.h>
  44 #include <asm/page.h>
  45 #include <asm/pcic.h>
  46 #include <asm/irq_regs.h>
  47
  48 #include "irq.h"
  49
  50 DEFINE_SPINLOCK(rtc_lock);
  51 static int set_rtc_mmss(unsigned long);
  52 static int sbus_do_settimeofday(struct timespec *tv);
  53
  54 unsigned long profile_pc(struct pt_regs *regs)
  55 {
  56         extern char __copy_user_begin[], __copy_user_end[];
  57         extern char __atomic_begin[], __atomic_end[];
  58         extern char __bzero_begin[], __bzero_end[];
  59
  60         unsigned long pc = regs->pc;
  61
  62         if (in_lock_functions(pc) ||
  63             (pc >= (unsigned long) __copy_user_begin &&
  64              pc < (unsigned long) __copy_user_end) ||
  65             (pc >= (unsigned long) __atomic_begin &&
  66              pc < (unsigned long) __atomic_end) ||
  67             (pc >= (unsigned long) __bzero_begin &&
  68              pc < (unsigned long) __bzero_end))
  69                 pc = regs->u_regs[UREG_RETPC];
  70         return pc;
  71 }
  72
  73 EXPORT_SYMBOL(profile_pc);
  74
  75 __volatile__ unsigned int *master_l10_counter;
  76
  77 /*
  78  * timer_interrupt() needs to keep up the real-time clock,
  79  * as well as call the "do_timer()" routine every clocktick
  80  */
  81
  82 #define TICK_SIZE (tick_nsec / 1000)
  83
  84 static irqreturn_t timer_interrupt(int dummy, void *dev_id)
  85 {
  86         /* last time the cmos clock got updated */
  87         static long last_rtc_update;
  88
  89 #ifndef CONFIG_SMP
  90         profile_tick(CPU_PROFILING);
  91 #endif
  92
  93         /* Protect counter clear so that do_gettimeoffset works */
  94         write_seqlock(&xtime_lock);
  95
  96         clear_clock_irq();
  97
  98         do_timer(1);
  99
 100         /* Determine when to update the Mostek clock. */
 101         if (ntp_synced() &&
 102             xtime.tv_sec > last_rtc_update + 660 &&
 103             (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
 104             (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
 105           if (set_rtc_mmss(xtime.tv_sec) == 0)
 106             last_rtc_update = xtime.tv_sec;
 107           else
 108             last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
 109         }
 110         write_sequnlock(&xtime_lock);
 111
 112 #ifndef CONFIG_SMP
 113         update_process_times(user_mode(get_irq_regs()));
 114 #endif
 115         return IRQ_HANDLED;
 116 }
 117
 118 static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
 119 {
 120         struct platform_device *pdev = to_platform_device(dev);
 121         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 122
 123         return readb(pdata->ioaddr + ofs);
 124 }
 125
 126 static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
 127 {
 128         struct platform_device *pdev = to_platform_device(dev);
 129         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 130
 131         writeb(val, pdata->ioaddr + ofs);
 132 }
 133
 134 static struct m48t59_plat_data m48t59_data = {
 135         .read_byte = mostek_read_byte,
 136         .write_byte = mostek_write_byte,
 137 };
 138
 139 /* resource is set at runtime */
 140 static struct platform_device m48t59_rtc = {
 141         .name           = "rtc-m48t59",
 142         .id             = 0,
 143         .num_resources  = 1,
 144         .dev    = {
 145                 .platform_data = &m48t59_data,
 146         },
 147 };
 148
 149 static int __devinit clock_probe(struct of_device *op, const struct of_device_id *match)
 150 {
 151         struct device_node *dp = op->node;
 152         const char *model = of_get_property(dp, "model", NULL);
 153
 154         if (!model)
 155                 return -ENODEV;
 156
 157         m48t59_rtc.resource = &op->resource[0];
 158         if (!strcmp(model, "mk48t02")) {
 159                 /* Map the clock register io area read-only */
 160                 m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
 161                                                 2048, "rtc-m48t59");
 162                 m48t59_data.type = M48T59RTC_TYPE_M48T02;
 163         } else if (!strcmp(model, "mk48t08")) {
 164                 m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
 165                                                 8192, "rtc-m48t59");
 166                 m48t59_data.type = M48T59RTC_TYPE_M48T08;
 167         } else
 168                 return -ENODEV;
 169
 170         if (platform_device_register(&m48t59_rtc) < 0)
 171                 printk(KERN_ERR "Registering RTC device failed\n");
 172
 173         return 0;
 174 }
 175
 176 static struct of_device_id __initdata clock_match[] = {
 177         {
 178                 .name = "eeprom",
 179         },
 180         {},
 181 };
 182
 183 static struct of_platform_driver clock_driver = {
 184         .match_table    = clock_match,
 185         .probe          = clock_probe,
 186         .driver         = {
 187                 .name   = "rtc",
 188         },
 189 };
 190
 191
 192 /* Probe for the mostek real time clock chip. */
 193 static int __init clock_init(void)
 194 {
 195         return of_register_driver(&clock_driver, &of_platform_bus_type);
 196 }
 197
 198 /* Must be after subsys_initcall() so that busses are probed.  Must
 199  * be before device_initcall() because things like the RTC driver
 200  * need to see the clock registers.
 201  */
 202 fs_initcall(clock_init);
 203
 204 static void __init sbus_time_init(void)
 205 {
 206
 207         BTFIXUPSET_CALL(bus_do_settimeofday, sbus_do_settimeofday, BTFIXUPCALL_NORM);
 208         btfixup();
 209
 210         sparc_init_timers(timer_interrupt);
 211
 212         /* Now that OBP ticker has been silenced, it is safe to enable IRQ. */
 213         local_irq_enable();
 214 }
 215
 216 void __init time_init(void)
 217 {
 218 #ifdef CONFIG_PCI
 219         extern void pci_time_init(void);
 220         if (pcic_present()) {
 221                 pci_time_init();
 222                 return;
 223         }
 224 #endif
 225         sbus_time_init();
 226 }
 227
 228 static inline unsigned long do_gettimeoffset(void)
 229 {
 230         unsigned long val = *master_l10_counter;
 231         unsigned long usec = (val >> 10) & 0x1fffff;
 232
 233         /* Limit hit?  */
 234         if (val & 0x80000000)
 235                 usec += 1000000 / HZ;
 236
 237         return usec;
 238 }
 239
 240 /* Ok, my cute asm atomicity trick doesn't work anymore.
 241  * There are just too many variables that need to be protected
 242  * now (both members of xtime, et al.)
 243  */
 244 void do_gettimeofday(struct timeval *tv)
 245 {
 246         unsigned long flags;
 247         unsigned long seq;
 248         unsigned long usec, sec;
 249         unsigned long max_ntp_tick = tick_usec - tickadj;
 250
 251         do {
 252                 seq = read_seqbegin_irqsave(&xtime_lock, flags);
 253                 usec = do_gettimeoffset();
 254
 255                 /*
 256                  * If time_adjust is negative then NTP is slowing the clock
 257                  * so make sure not to go into next possible interval.
 258                  * Better to lose some accuracy than have time go backwards..
 259                  */
 260                 if (unlikely(time_adjust < 0))
 261                         usec = min(usec, max_ntp_tick);
 262
 263                 sec = xtime.tv_sec;
 264                 usec += (xtime.tv_nsec / 1000);
 265         } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
 266
 267         while (usec >= 1000000) {
 268                 usec -= 1000000;
 269                 sec++;
 270         }
 271
 272         tv->tv_sec = sec;
 273         tv->tv_usec = usec;
 274 }
 275
 276 EXPORT_SYMBOL(do_gettimeofday);
 277
 278 int do_settimeofday(struct timespec *tv)
 279 {
 280         int ret;
 281
 282         write_seqlock_irq(&xtime_lock);
 283         ret = bus_do_settimeofday(tv);
 284         write_sequnlock_irq(&xtime_lock);
 285         clock_was_set();
 286         return ret;
 287 }
 288
 289 EXPORT_SYMBOL(do_settimeofday);
 290
 291 static int sbus_do_settimeofday(struct timespec *tv)
 292 {
 293         time_t wtm_sec, sec = tv->tv_sec;
 294         long wtm_nsec, nsec = tv->tv_nsec;
 295
 296         if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 297                 return -EINVAL;
 298
 299         /*
 300          * This is revolting. We need to set "xtime" correctly. However, the
 301          * value in this location is the value at the most recent update of
 302          * wall time.  Discover what correction gettimeofday() would have
 303          * made, and then undo it!
 304          */
 305         nsec -= 1000 * do_gettimeoffset();
 306
 307         wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
 308         wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
 309
 310         set_normalized_timespec(&xtime, sec, nsec);
 311         set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 312
 313         ntp_clear();
 314         return 0;
 315 }
 316
 317 static int set_rtc_mmss(unsigned long secs)
 318 {
 319         struct rtc_device *rtc = rtc_class_open("rtc0");
 320         int err = -1;
 321
 322         if (rtc) {
 323                 err = rtc_set_mmss(rtc, secs);
 324                 rtc_class_close(rtc);
 325         }
 326
 327         return err;
 328 }