kernel/arch/x86_64/timer.c

   1 /*
   2  *  ZeX/OS
   3  *  Copyright (C) 2008  Tomas 'ZeXx86' Jedrzejek (zexx86@zexos.org)
   4  *
   5  *  This program is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19
  20 #include <system.h>
  21 #include <arch/io.h>
  22 #include <string.h>
  23
  24 /* This will keep track of how many ticks that the system
  25 *  has been running for */
  26 unsigned long timer_ticks = 0;
  27
  28 /* Software timer - ticks count to 1ms */
  29 unsigned long timer_swticks = 0;
  30
  31 /* Handles the timer. In this case, it's very simple: We
  32 *  increment the 'timer_ticks' variable every time the
  33 *  timer fires. By default, the timer fires 18.222 times
  34 *  per second. Why 18.222Hz? Some engineer at IBM must've
  35 *  been smoking something funky */
  36 void timer_handler (struct regs *r)
  37 {
  38         /* Increment our 'tick count' */
  39         timer_ticks ++;
  40 }
  41
  42 /* This will continuously loop until the given time has
  43 *  been reached */
  44 void timer_wait (int ticks)
  45 {
  46         int eticks;
  47
  48         eticks = timer_ticks + ticks;
  49
  50         while (timer_ticks < eticks)
  51                 kprintf("");;
  52 }
  53
  54 char *time_tostring (unsigned long s)
  55 {
  56         static char buffer[512];
  57         unsigned int weeks, days, hours, minutes, seconds, total;
  58
  59         seconds = s % 60;
  60         minutes = s / 60;
  61         hours = minutes / 60;
  62         days = hours / 24;
  63         weeks = days / 7;
  64         minutes = minutes % 60;
  65         hours = hours % 24;
  66         days = days % 7;
  67
  68         total = 0;
  69
  70         if (weeks)
  71                 total += sprintf (buffer, "%u week%s, ", weeks, (weeks > 1) ? "s" : "");
  72         if (days)
  73                 total += sprintf (buffer + total, "%u day%s, ", days, (days > 1) ? "s" : "");
  74
  75         if ((hours || minutes || seconds) || (!(weeks || days)))
  76                 total += sprintf (buffer + total, "%2uh %2umin %2usec", hours, minutes, seconds);
  77
  78         return buffer;
  79 }
  80
  81 void uptime (void)
  82 {
  83         printf ("Uptime: %s\n", time_tostring (timer_ticks/((3579545L / 3) / HZ)));
  84 }
  85
  86 void calc_freqency ()
  87 {
  88         /* Kernel with 1000Hz timer dont need it */
  89         if (kernel_attr & KERNEL_18HZ) {
  90                 int eticks;
  91
  92                 eticks = timer_ticks + 18;
  93
  94                 while (timer_ticks < eticks) {
  95                         ctps ++;
  96                         kprintf("");;
  97                 }
  98
  99                 kprintf ("Freqency: %lluHz\n", ctps);
 100         }
 101 }
 102
 103 void calc_swtimer ()
 104 {
 105         unsigned long timer = timer_ticks;
 106
 107         while ((timer_ticks - timer) >= 1)
 108                 timer_swticks ++;
 109 }
 110
 111 void usleep (unsigned len)
 112 {
 113         if (kernel_attr & KERNEL_18HZ) {
 114                 unsigned long long t = ctps * len;
 115                 unsigned long long i = 0;
 116
 117                 while (t > i) {
 118                         i += 1000;
 119                         kprintf("");;
 120                 }
 121         } else
 122                 timer_wait (1);
 123 }
 124
 125 void init_8253 ()
 126 {
 127         if (kernel_attr & KERNEL_18HZ) {        // Dont set new timer frequency, when is setted KERNEL_18HZ
 128                 kprintf ("Warning -> kernel is set to 18HZ timer frequency !\n");
 129                 #undef HZ
 130                 #define HZ 18
 131                 return;
 132         }
 133
 134         unsigned foo = (3579545L / 3) / HZ;
 135
 136         /* reprogram the 8253 timer chip to run at 'HZ', instead of 18 Hz */
 137         outb (0x43, 0x36);      /* channel 0, LSB/MSB, mode 3, binary */
 138         outb (0x40, (unsigned short) foo & 0xFF);       /* LSB */
 139         outb (0x40, (unsigned short) foo >> 8); /* MSB */
 140 }
 141
 142 /* Sets up the system clock by installing the timer handler into IRQ0 */
 143 unsigned int timer_install ()
 144 {
 145         /* set hw timer (irq0) to HZ frequency */
 146         init_8253 ();
 147
 148         /* Installs 'timer_handler' to IRQ0 */
 149         // TODO: irq_install_handler (0, timer_handler);
 150
 151         return 1;
 152 }