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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. /** @addtogroup ia32   
  30.  * @{
  31.  */
  32. /**
  33.  * @file
  34.  * @brief   i8254 chip driver.
  35.  *
  36.  * Low level time functions.
  37.  */
  38.  
  39. #include <arch/types.h>
  40. #include <time/clock.h>
  41. #include <time/delay.h>
  42. #include <arch/interrupt.h>
  43. #include <arch/drivers/i8259.h>
  44. #include <arch/drivers/i8254.h>
  45. #include <cpu.h>
  46. #include <config.h>
  47. #include <arch/pm.h>
  48. #include <arch/asm.h>
  49. #include <arch/cpuid.h>
  50. #include <arch.h>
  51. #include <time/delay.h>
  52. #include <interrupt.h>
  53.  
  54. #define CLK_PORT1   0x40
  55. #define CLK_PORT4   0x43
  56.  
  57. #define CLK_CONST   1193180
  58. #define MAGIC_NUMBER    1194
  59.  
  60. static void i8254_interrupt(int n, istate_t *istate);
  61.  
  62. void i8254_init(void)
  63. {
  64.     i8254_normal_operation();
  65. }
  66.  
  67. void i8254_normal_operation(void)
  68. {
  69.     outb(CLK_PORT4, 0x36);
  70.     pic_disable_irqs(1<<IRQ_CLK);
  71.     outb(CLK_PORT1, (CLK_CONST/HZ) & 0xf);
  72.     outb(CLK_PORT1, (CLK_CONST/HZ) >> 8);
  73.     pic_enable_irqs(1<<IRQ_CLK);
  74.     exc_register(VECTOR_CLK, "i8254_clock", (iroutine) i8254_interrupt);
  75. }
  76.  
  77. #define LOOPS 150000
  78. #define SHIFT 11
  79. void i8254_calibrate_delay_loop(void)
  80. {
  81.     __u64 clk1, clk2;
  82.     __u32 t1, t2, o1, o2;
  83.     __u8 not_ok;
  84.  
  85.  
  86.     /*
  87.      * One-shot timer. Count-down from 0xffff at 1193180Hz
  88.      * MAGIC_NUMBER is the magic value for 1ms.
  89.      */
  90.     outb(CLK_PORT4, 0x30);
  91.     outb(CLK_PORT1, 0xff);
  92.     outb(CLK_PORT1, 0xff);
  93.  
  94.     do {
  95.         /* will read both status and count */
  96.         outb(CLK_PORT4, 0xc2);
  97.         not_ok = (inb(CLK_PORT1)>>6)&1;
  98.         t1 = inb(CLK_PORT1);
  99.         t1 |= inb(CLK_PORT1) << 8;
  100.     } while (not_ok);
  101.  
  102.     asm_delay_loop(LOOPS);
  103.  
  104.     outb(CLK_PORT4, 0xd2);
  105.     t2 = inb(CLK_PORT1);
  106.     t2 |= inb(CLK_PORT1) << 8;
  107.  
  108.     /*
  109.      * We want to determine the overhead of the calibrating mechanism.
  110.      */
  111.     outb(CLK_PORT4, 0xd2);
  112.     o1 = inb(CLK_PORT1);
  113.     o1 |= inb(CLK_PORT1) << 8;
  114.  
  115.     asm_fake_loop(LOOPS);
  116.  
  117.     outb(CLK_PORT4, 0xd2);
  118.     o2 = inb(CLK_PORT1);
  119.     o2 |= inb(CLK_PORT1) << 8;
  120.  
  121.     CPU->delay_loop_const = ((MAGIC_NUMBER*LOOPS)/1000) / ((t1-t2)-(o1-o2)) + (((MAGIC_NUMBER*LOOPS)/1000) % ((t1-t2)-(o1-o2)) ? 1 : 0);
  122.  
  123.     clk1 = rdtsc();
  124.     delay(1<<SHIFT);
  125.     clk2 = rdtsc();
  126.    
  127.     CPU->frequency_mhz = (clk2-clk1)>>SHIFT;
  128.  
  129.     return;
  130. }
  131.  
  132. void i8254_interrupt(int n, istate_t *istate)
  133. {
  134.     trap_virtual_eoi();
  135.     clock();
  136. }
  137.  
  138. /** @}
  139.  */
  140.