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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/drivers/i8259.h>
  34. #include <arch/drivers/i8254.h>
  35. #include <cpu.h>
  36. #include <config.h>
  37. #include <arch/pm.h>
  38. #include <arch/asm.h>
  39. #include <arch/cpuid.h>
  40. #include <arch.h>
  41. #include <time/delay.h>
  42. #include <interrupt.h>
  43.  
  44. /*
  45.  * i8254 chip driver.
  46.  * Low level time functions.
  47.  */
  48.  
  49. #define CLK_PORT1   0x40
  50. #define CLK_PORT4   0x43
  51.  
  52.  
  53. #define CLK_CONST   1193180
  54. #define MAGIC_NUMBER    1194
  55.  
  56. static void i8254_interrupt(int n, istate_t *istate);
  57.  
  58. void i8254_init(void)
  59. {
  60.     i8254_normal_operation();
  61. }
  62.  
  63. void i8254_normal_operation(void)
  64. {
  65.     outb(CLK_PORT4, 0x36);
  66.     pic_disable_irqs(1<<IRQ_CLK);
  67.     outb(CLK_PORT1, (CLK_CONST/HZ) & 0xf);
  68.     outb(CLK_PORT1, (CLK_CONST/HZ) >> 8);
  69.     pic_enable_irqs(1<<IRQ_CLK);
  70.     exc_register(VECTOR_CLK, "i8254_clock", (iroutine) i8254_interrupt);
  71. }
  72.  
  73. #define LOOPS 150000
  74. #define SHIFT 11
  75. void i8254_calibrate_delay_loop(void)
  76. {
  77.     __u64 clk1, clk2;
  78.     __u32 t1, t2, o1, o2;
  79.     __u8 not_ok;
  80.  
  81.  
  82.     /*
  83.      * One-shot timer. Count-down from 0xffff at 1193180Hz
  84.      * MAGIC_NUMBER is the magic value for 1ms.
  85.      */
  86.     outb(CLK_PORT4, 0x30);
  87.     outb(CLK_PORT1, 0xff);
  88.     outb(CLK_PORT1, 0xff);
  89.  
  90.     do {
  91.         /* will read both status and count */
  92.         outb(CLK_PORT4, 0xc2);
  93.         not_ok = (inb(CLK_PORT1)>>6)&1;
  94.         t1 = inb(CLK_PORT1);
  95.         t1 |= inb(CLK_PORT1) << 8;
  96.     } while (not_ok);
  97.  
  98.     asm_delay_loop(LOOPS);
  99.  
  100.     outb(CLK_PORT4, 0xd2);
  101.     t2 = inb(CLK_PORT1);
  102.     t2 |= inb(CLK_PORT1) << 8;
  103.  
  104.     /*
  105.      * We want to determine the overhead of the calibrating mechanism.
  106.      */
  107.     outb(CLK_PORT4, 0xd2);
  108.     o1 = inb(CLK_PORT1);
  109.     o1 |= inb(CLK_PORT1) << 8;
  110.  
  111.     asm_fake_loop(LOOPS);
  112.  
  113.     outb(CLK_PORT4, 0xd2);
  114.     o2 = inb(CLK_PORT1);
  115.     o2 |= inb(CLK_PORT1) << 8;
  116.  
  117.     CPU->delay_loop_const = ((MAGIC_NUMBER*LOOPS)/1000) / ((t1-t2)-(o1-o2)) + (((MAGIC_NUMBER*LOOPS)/1000) % ((t1-t2)-(o1-o2)) ? 1 : 0);
  118.  
  119.     clk1 = rdtsc();
  120.     delay(1<<SHIFT);
  121.     clk2 = rdtsc();
  122.    
  123.     CPU->frequency_mhz = (clk2-clk1)>>SHIFT;
  124.  
  125.     return;
  126. }
  127.  
  128. void i8254_interrupt(int n, istate_t *istate)
  129. {
  130.     trap_virtual_eoi();
  131.     clock();
  132. }
  133.