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 <commonlib/bsd/gcd.h>
 42  #include <inttypes.h>
 43  
 44  extern u32 cpu_khz;
 45  
 46  static struct {
 47  	u64 ticks;
 48  	time_t secs;
 49  	suseconds_t usecs;
 50  } clock;
 51  
 52  static void update_clock(void)
 53  {
 54  	u64 delta = timer_raw_value() - clock.ticks;
 55  	int secs;
 56  	static uint64_t ticks_per_sec = 0;
 57  	static uint64_t ticks_per_usec = 0;
 58  	if (!ticks_per_sec) {
 59  		ticks_per_sec = timer_hz();
 60  		ticks_per_usec = timer_hz() / 1000000;
 61  	}
 62  
 63  	clock.ticks += delta;
 64  
 65  	secs = (int) (delta / ticks_per_sec);
 66  	clock.secs += secs;
 67  	delta -= (secs * ticks_per_sec);
 68  	clock.usecs += (int)(delta / ticks_per_usec);
 69  
 70  	if (clock.usecs > 1000000) {
 71  		clock.usecs -= 1000000;
 72  		clock.secs++;
 73  	}
 74  }
 75  
 76  #if CONFIG(LP_NVRAM)
 77  
 78  static unsigned int day_of_year(int mon, int day, int year)
 79  {
 80  	static u8 mdays[12] = { 31, 28, 31, 30, 31, 30,
 81  				31, 31, 30, 31, 30, 31 };
 82  
 83  	int i, ret = 0;
 84  
 85  	for(i = 0; i < mon; i++) {
 86  		ret += mdays[i];
 87  
 88  		if (i == 1 && (year % 4))
 89  			ret++;
 90  	}
 91  
 92  	return (ret + day);
 93  }
 94  
 95  static void gettimeofday_init(void)
 96  {
 97  	int days, delta;
 98  	struct tm tm;
 99  
100  	rtc_read_clock(&tm);
101  	clock.ticks = rdtsc();
102  
103  	/* Calculate the number of days in the year so far */
104  	days = day_of_year(tm.tm_mon, tm.tm_mday, tm.tm_year + 1900);
105  
106  	delta = tm.tm_year - 70;
107  
108  	days += (delta * 365);
109  
110  	/* Figure leap years */
111  
112  	if (delta > 2)
113  	  days += (delta - 2) / 4;
114  
115  	clock.secs = (days * 86400) + (tm.tm_hour * 3600) +
116  		(tm.tm_min * 60) + tm.tm_sec;
117  }
118  #else
119  static void gettimeofday_init(void)
120  {
121  	/* Record the number of ticks */
122  	clock.ticks = timer_raw_value();
123  }
124  #endif
125  
126  /**
127   * Return the current time expressed as seconds from 00:00:00 UTC, 1 Jan 1970.
128   *
129   * @param tp When not NULL, set this to the current time in seconds.
130   * @return The current time in seconds.
131   */
132  time_t time(time_t *tp)
133  {
134  	/*
135  	 * Call the gtod init when we need it - this keeps the code from
136  	 * being included in the binary if we don't need it.
137  	 */
138  	if (!clock.ticks)
139  		gettimeofday_init();
140  
141  	update_clock();
142  
143  	if (tp)
144  		*tp = clock.secs;
145  
146  	return clock.secs;
147  }
148  
149  /**
150   * Return the current time broken into a timeval structure.
151   *
152   * @param tv A pointer to a timeval structure.
153   * @param tz Added for compatibility - not used.
154   * @return 0 for success (this function cannot return non-zero currently).
155   */
156  int gettimeofday(struct timeval *tv, void *tz)
157  {
158  	tv->tv_sec = time(NULL);
159  	tv->tv_usec = clock.usecs;
160  
161  	return 0;
162  }
163  
164  __attribute__((weak))
165  void arch_ndelay(uint64_t ns)
166  {
167  	uint64_t delta = ns * timer_hz() / NSECS_PER_SEC;
168  	uint64_t start = timer_raw_value();
169  	while (timer_raw_value() - start < delta) ;
170  }
171  
172  u64 timer_us(u64 base)
173  {
174  	static u64 hz;
175  	static u32 mult = USECS_PER_SEC;
176  	u32 div;
177  
178  	// Only check timer_hz once. Assume it doesn't change.
179  	if (hz == 0) {
180  		hz = timer_hz();
181  		if (hz < mult) {
182  			printf("Timer frequency %" PRIu64 " is too low, "
183  			       "must be at least 1MHz.\n", hz);
184  			halt();
185  		}
186  		div = gcd(hz, mult);
187  		hz /= div;
188  		mult /= div;
189  	}
190  
191  	return (mult * timer_raw_value()) / hz - base;
192  }