arch/sparc/kernel/time_32.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 EXPORT_SYMBOL(rtc_lock);
  52
  53 static int set_rtc_mmss(unsigned long);
  54 static int sbus_do_settimeofday(struct timespec *tv);
  55
  56 unsigned long profile_pc(struct pt_regs *regs)
  57 {
  58         extern char __copy_user_begin[], __copy_user_end[];
  59         extern char __atomic_begin[], __atomic_end[];
  60         extern char __bzero_begin[], __bzero_end[];
  61
  62         unsigned long pc = regs->pc;
  63
  64         if (in_lock_functions(pc) ||
  65             (pc >= (unsigned long) __copy_user_begin &&
  66              pc < (unsigned long) __copy_user_end) ||
  67             (pc >= (unsigned long) __atomic_begin &&
  68              pc < (unsigned long) __atomic_end) ||
  69             (pc >= (unsigned long) __bzero_begin &&
  70              pc < (unsigned long) __bzero_end))
  71                 pc = regs->u_regs[UREG_RETPC];
  72         return pc;
  73 }
  74
  75 EXPORT_SYMBOL(profile_pc);
  76
  77 __volatile__ unsigned int *master_l10_counter;
  78
  79 /*
  80  * timer_interrupt() needs to keep up the real-time clock,
  81  * as well as call the "do_timer()" routine every clocktick
  82  */
  83
  84 #define TICK_SIZE (tick_nsec / 1000)
  85
  86 static irqreturn_t timer_interrupt(int dummy, void *dev_id)
  87 {
  88         /* last time the cmos clock got updated */
  89         static long last_rtc_update;
  90
  91 #ifndef CONFIG_SMP
  92         profile_tick(CPU_PROFILING);
  93 #endif
  94
  95         /* Protect counter clear so that do_gettimeoffset works */
  96         write_seqlock(&xtime_lock);
  97
  98         clear_clock_irq();
  99
 100         do_timer(1);
 101
 102         /* Determine when to update the Mostek clock. */
 103         if (ntp_synced() &&
 104             xtime.tv_sec > last_rtc_update + 660 &&
 105             (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
 106             (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
 107           if (set_rtc_mmss(xtime.tv_sec) == 0)
 108             last_rtc_update = xtime.tv_sec;
 109           else
 110             last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */
 111         }
 112         write_sequnlock(&xtime_lock);
 113
 114 #ifndef CONFIG_SMP
 115         update_process_times(user_mode(get_irq_regs()));
 116 #endif
 117         return IRQ_HANDLED;
 118 }
 119
 120 static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
 121 {
 122         struct platform_device *pdev = to_platform_device(dev);
 123         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 124
 125         return readb(pdata->ioaddr + ofs);
 126 }
 127
 128 static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
 129 {
 130         struct platform_device *pdev = to_platform_device(dev);
 131         struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 132
 133         writeb(val, pdata->ioaddr + ofs);
 134 }
 135
 136 static struct m48t59_plat_data m48t59_data = {
 137         .read_byte = mostek_read_byte,
 138         .write_byte = mostek_write_byte,
 139 };
 140
 141 /* resource is set at runtime */
 142 static struct platform_device m48t59_rtc = {
 143         .name           = "rtc-m48t59",
 144         .id             = 0,
 145         .num_resources  = 1,
 146         .dev    = {
 147                 .platform_data = &m48t59_data,
 148         },
 149 };
 150
 151 static int __devinit clock_probe(struct of_device *op, const struct of_device_id *match)
 152 {
 153         struct device_node *dp = op->node;
 154         const char *model = of_get_property(dp, "model", NULL);
 155
 156         if (!model)
 157                 return -ENODEV;
 158
 159         m48t59_rtc.resource = &op->resource[0];
 160         if (!strcmp(model, "mk48t02")) {
 161                 /* Map the clock register io area read-only */
 162                 m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
 163                                                 2048, "rtc-m48t59");
 164                 m48t59_data.type = M48T59RTC_TYPE_M48T02;
 165         } else if (!strcmp(model, "mk48t08")) {
 166                 m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
 167                                                 8192, "rtc-m48t59");
 168                 m48t59_data.type = M48T59RTC_TYPE_M48T08;
 169         } else
 170                 return -ENODEV;
 171
 172         if (platform_device_register(&m48t59_rtc) < 0)
 173                 printk(KERN_ERR "Registering RTC device failed\n");
 174
 175         return 0;
 176 }
 177
 178 static struct of_device_id __initdata clock_match[] = {
 179         {
 180                 .name = "eeprom",
 181         },
 182         {},
 183 };
 184
 185 static struct of_platform_driver clock_driver = {
 186         .match_table    = clock_match,
 187         .probe          = clock_probe,
 188         .driver         = {
 189                 .name   = "rtc",
 190         },
 191 };
 192
 193
 194 /* Probe for the mostek real time clock chip. */
 195 static int __init clock_init(void)
 196 {
 197         return of_register_driver(&clock_driver, &of_platform_bus_type);
 198 }
 199
 200 /* Must be after subsys_initcall() so that busses are probed.  Must
 201  * be before device_initcall() because things like the RTC driver
 202  * need to see the clock registers.
 203  */
 204 fs_initcall(clock_init);
 205
 206 static void __init sbus_time_init(void)
 207 {
 208
 209         BTFIXUPSET_CALL(bus_do_settimeofday, sbus_do_settimeofday, BTFIXUPCALL_NORM);
 210         btfixup();
 211
 212         sparc_init_timers(timer_interrupt);
 213 }
 214
 215 void __init time_init(void)
 216 {
 217 #ifdef CONFIG_PCI
 218         extern void pci_time_init(void);
 219         if (pcic_present()) {
 220                 pci_time_init();
 221                 return;
 222         }
 223 #endif
 224         sbus_time_init();
 225 }
 226
 227 static inline unsigned long do_gettimeoffset(void)
 228 {
 229         unsigned long val = *master_l10_counter;
 230         unsigned long usec = (val >> 10) & 0x1fffff;
 231
 232         /* Limit hit?  */
 233         if (val & 0x80000000)
 234                 usec += 1000000 / HZ;
 235
 236         return usec;
 237 }
 238
 239 /* Ok, my cute asm atomicity trick doesn't work anymore.
 240  * There are just too many variables that need to be protected
 241  * now (both members of xtime, et al.)
 242  */
 243 void do_gettimeofday(struct timeval *tv)
 244 {
 245         unsigned long flags;
 246         unsigned long seq;
 247         unsigned long usec, sec;
 248         unsigned long max_ntp_tick = tick_usec - tickadj;
 249
 250         do {
 251                 seq = read_seqbegin_irqsave(&xtime_lock, flags);
 252                 usec = do_gettimeoffset();
 253
 254                 /*
 255                  * If time_adjust is negative then NTP is slowing the clock
 256                  * so make sure not to go into next possible interval.
 257                  * Better to lose some accuracy than have time go backwards..
 258                  */
 259                 if (unlikely(time_adjust < 0))
 260                         usec = min(usec, max_ntp_tick);
 261
 262                 sec = xtime.tv_sec;
 263                 usec += (xtime.tv_nsec / 1000);
 264         } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
 265
 266         while (usec >= 1000000) {
 267                 usec -= 1000000;
 268                 sec++;
 269         }
 270
 271         tv->tv_sec = sec;
 272         tv->tv_usec = usec;
 273 }
 274
 275 EXPORT_SYMBOL(do_gettimeofday);
 276
 277 int do_settimeofday(struct timespec *tv)
 278 {
 279         int ret;
 280
 281         write_seqlock_irq(&xtime_lock);
 282         ret = bus_do_settimeofday(tv);
 283         write_sequnlock_irq(&xtime_lock);
 284         clock_was_set();
 285         return ret;
 286 }
 287
 288 EXPORT_SYMBOL(do_settimeofday);
 289
 290 static int sbus_do_settimeofday(struct timespec *tv)
 291 {
 292         time_t wtm_sec, sec = tv->tv_sec;
 293         long wtm_nsec, nsec = tv->tv_nsec;
 294
 295         if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
 296                 return -EINVAL;
 297
 298         /*
 299          * This is revolting. We need to set "xtime" correctly. However, the
 300          * value in this location is the value at the most recent update of
 301          * wall time.  Discover what correction gettimeofday() would have
 302          * made, and then undo it!
 303          */
 304         nsec -= 1000 * do_gettimeoffset();
 305
 306         wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
 307         wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
 308
 309         set_normalized_timespec(&xtime, sec, nsec);
 310         set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 311
 312         ntp_clear();
 313         return 0;
 314 }
 315
 316 static int set_rtc_mmss(unsigned long secs)
 317 {
 318         struct rtc_device *rtc = rtc_class_open("rtc0");
 319         int err = -1;
 320
 321         if (rtc) {
 322                 err = rtc_set_mmss(rtc, secs);
 323                 rtc_class_close(rtc);
 324         }
 325
 326         return err;
 327 }