payloads/libpayload/libc/time.c

   1 /*
   2  *
   3  * Copyright (C) 2008 Advanced Micro Devices, Inc.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 /**
  30  * @file libc/time.c
  31  * General time functions
  32  */
  33
  34 #define __STDC_FORMAT_MACROS
  35
  36 #include <libpayload-config.h>
  37 #include <libpayload.h>
  38 #if CONFIG(LP_ARCH_X86) && CONFIG(LP_NVRAM)
  39 #include <arch/rdtsc.h>
  40 #endif
  41 #include <inttypes.h>
  42
  43 extern u32 cpu_khz;
  44
  45 static struct {
  46         u64 ticks;
  47         time_t secs;
  48         suseconds_t usecs;
  49 } clock;
  50
  51 static void update_clock(void)
  52 {
  53         u64 delta = timer_raw_value() - clock.ticks;
  54         int secs;
  55         static uint64_t ticks_per_sec = 0;
  56         static uint64_t ticks_per_usec = 0;
  57         if (!ticks_per_sec) {
  58                 ticks_per_sec = timer_hz();
  59                 ticks_per_usec = timer_hz() / 1000000;
  60         }
  61
  62         clock.ticks += delta;
  63
  64         secs = (int) (delta / ticks_per_sec);
  65         clock.secs += secs;
  66         delta -= (secs * ticks_per_sec);
  67         clock.usecs += (int)(delta / ticks_per_usec);
  68
  69         if (clock.usecs > 1000000) {
  70                 clock.usecs -= 1000000;
  71                 clock.secs++;
  72         }
  73 }
  74
  75 #if CONFIG(LP_NVRAM)
  76
  77 static unsigned int day_of_year(int mon, int day, int year)
  78 {
  79         static u8 mdays[12] = { 31, 28, 31, 30, 31, 30,
  80                                 31, 31, 30, 31, 30, 31 };
  81
  82         int i, ret = 0;
  83
  84         for(i = 0; i < mon; i++) {
  85                 ret += mdays[i];
  86
  87                 if (i == 1 && (year % 4))
  88                         ret++;
  89         }
  90
  91         return (ret + day);
  92 }
  93
  94 static void gettimeofday_init(void)
  95 {
  96         int days, delta;
  97         struct tm tm;
  98
  99         rtc_read_clock(&tm);
 100         clock.ticks = rdtsc();
 101
 102         /* Calculate the number of days in the year so far */
 103         days = day_of_year(tm.tm_mon, tm.tm_mday, tm.tm_year + 1900);
 104
 105         delta = tm.tm_year - 70;
 106
 107         days += (delta * 365);
 108
 109         /* Figure leap years */
 110
 111         if (delta > 2)
 112           days += (delta - 2) / 4;
 113
 114         clock.secs = (days * 86400) + (tm.tm_hour * 3600) +
 115                 (tm.tm_min * 60) + tm.tm_sec;
 116 }
 117 #else
 118 static void gettimeofday_init(void)
 119 {
 120         /* Record the number of ticks */
 121         clock.ticks = timer_raw_value();
 122 }
 123 #endif
 124
 125 /**
 126  * Return the current time expressed as seconds from 00:00:00 UTC, 1 Jan 1970.
 127  *
 128  * @param tp When not NULL, set this to the current time in seconds.
 129  * @return The current time in seconds.
 130  */
 131 time_t time(time_t *tp)
 132 {
 133         /*
 134          * Call the gtod init when we need it - this keeps the code from
 135          * being included in the binary if we don't need it.
 136          */
 137         if (!clock.ticks)
 138                 gettimeofday_init();
 139
 140         update_clock();
 141
 142         if (tp)
 143                 *tp = clock.secs;
 144
 145         return clock.secs;
 146 }
 147
 148 /**
 149  * Return the current time broken into a timeval structure.
 150  *
 151  * @param tv A pointer to a timeval structure.
 152  * @param tz Added for compatibility - not used.
 153  * @return 0 for success (this function cannot return non-zero currently).
 154  */
 155 int gettimeofday(struct timeval *tv, void *tz)
 156 {
 157         tv->tv_sec = time(NULL);
 158         tv->tv_usec = clock.usecs;
 159
 160         return 0;
 161 }
 162
 163 __attribute__((weak))
 164 void arch_ndelay(uint64_t ns)
 165 {
 166         uint64_t delta = ns * timer_hz() / NSECS_PER_SEC;
 167         uint64_t start = timer_raw_value();
 168         while (timer_raw_value() - start < delta) ;
 169 }
 170
 171 u64 timer_us(u64 base)
 172 {
 173         static u64 hz;
 174
 175         // Only check timer_hz once. Assume it doesn't change.
 176         if (hz == 0) {
 177                 hz = timer_hz();
 178                 if (hz < 1000000) {
 179                         printf("Timer frequency %" PRIu64 " is too low, "
 180                                "must be at least 1MHz.\n", hz);
 181                         halt();
 182                 }
 183         }
 184
 185         return (1000000 * timer_raw_value()) / hz - base;
 186 }