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  1. /*
  2.  * Copyright (C) 2001-2004 Jakub Jermar
  3.  * All rights reserved.
  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.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. #include <arch/types.h>
  30. #include <time/clock.h>
  31. #include <time/delay.h>
  32. #include <arch/interrupt.h>
  33. #include <arch/i8259.h>
  34. #include <arch/i8254.h>
  35. #include <cpu.h>
  36. #include <config.h>
  37. #include <arch/pm.h>
  38. #include <arch/asm.h>
  39. #include <arch.h>
  40.  
  41. /*
  42.  * i8254 chip driver.
  43.  * Low level time functions.
  44.  */
  45.  
  46. #define CLK_PORT1   0x40
  47. #define CLK_PORT4   0x43
  48.  
  49.  
  50. #define CLK_CONST   1193180
  51. #define MAGIC_NUMBER    1194
  52.  
  53. void i8254_init(void)
  54. {
  55.     i8254_normal_operation();
  56. }
  57.  
  58. void i8254_normal_operation(void)
  59. {
  60.     outb(CLK_PORT4, 0x36);
  61.     trap_virtual_disable_irqs(1<<IRQ_CLK);
  62.     outb(CLK_PORT1, (CLK_CONST/HZ) & 0xf);
  63.     outb(CLK_PORT1, (CLK_CONST/HZ) >> 8);
  64.     trap_virtual_enable_irqs(1<<IRQ_CLK);
  65.     trap_register(VECTOR_CLK, i8254_interrupt);
  66. }
  67.  
  68. #define LOOPS 150000
  69. #define SHIFT 11
  70. void i8254_calibrate_delay_loop(void)
  71. {
  72.     __u64 clk1, clk2;
  73.     __u32 t1, t2, o1, o2;
  74.     __u8 not_ok;
  75.  
  76.  
  77.     /*
  78.      * One-shot timer. Count-down from 0xffff at 1193180Hz
  79.      * MAGIC_NUMBER is the magic value for 1ms.
  80.      */
  81.     outb(CLK_PORT4, 0x30);
  82.     outb(CLK_PORT1, 0xff);
  83.     outb(CLK_PORT1, 0xff);
  84.  
  85.     do {
  86.             /* will read both status and count */
  87.         outb(CLK_PORT4, 0xc2);
  88.         not_ok = (inb(CLK_PORT1)>>6)&1;
  89.         t1 = inb(CLK_PORT1);
  90.         t1 |= inb(CLK_PORT1) << 8;
  91.     } while (not_ok);
  92.  
  93.     asm_delay_loop(LOOPS);
  94.  
  95.     outb(CLK_PORT4, 0xd2);
  96.     t2 = inb(CLK_PORT1);
  97.     t2 |= inb(CLK_PORT1) << 8;
  98.  
  99.     /*
  100.      * We want to determine the overhead of the calibrating mechanism.
  101.      */
  102.     outb(CLK_PORT4, 0xd2);
  103.     o1 = inb(CLK_PORT1);
  104.     o1 |= inb(CLK_PORT1) << 8;
  105.  
  106.     asm_fake_loop(LOOPS);
  107.  
  108.     outb(CLK_PORT4, 0xd2);
  109.     o2 = inb(CLK_PORT1);
  110.     o2 |= inb(CLK_PORT1) << 8;
  111.  
  112.  
  113.     the->cpu->delay_loop_const = ((MAGIC_NUMBER*LOOPS)/1000) / ((t1-t2)-(o1-o2)) +
  114.                     (((MAGIC_NUMBER*LOOPS)/1000) % ((t1-t2)-(o1-o2)) ? 1 : 0);
  115.    
  116.  
  117.     clk1 = rdtsc();
  118.     delay(1<<SHIFT);
  119.     clk2 = rdtsc();
  120.    
  121.     the->cpu->frequency_mhz = (clk2-clk1)>>SHIFT;
  122.  
  123.     return;
  124. }
  125.  
  126. void i8254_interrupt(__u8 n, __u32 stack[])
  127. {
  128.     trap_virtual_eoi();
  129.     clock();
  130. }
  131.