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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 <ddi/irq.h>
  53. #include <ddi/device.h>
  54.  
  55. #define CLK_PORT1   0x40
  56. #define CLK_PORT4   0x43
  57.  
  58. #define CLK_CONST   1193180
  59. #define MAGIC_NUMBER    1194
  60.  
  61. static irq_t i8254_irq;
  62.  
  63. static irq_ownership_t i8254_claim(void)
  64. {
  65.     return IRQ_ACCEPT;
  66. }
  67.  
  68. static void i8254_irq_handler(irq_t *irq, void *arg, ...)
  69. {
  70.     clock();
  71. }
  72.  
  73. void i8254_init(void)
  74. {
  75.     irq_initialize(&i8254_irq);
  76.     i8254_irq.devno = device_assign_devno();
  77.     i8254_irq.inr = IRQ_CLK;
  78.     i8254_irq.claim = i8254_claim;
  79.     i8254_irq.handler = i8254_irq_handler;
  80.     irq_register(&i8254_irq);
  81.    
  82.     i8254_normal_operation();
  83. }
  84.  
  85. void i8254_normal_operation(void)
  86. {
  87.     outb(CLK_PORT4, 0x36);
  88.     pic_disable_irqs(1 << IRQ_CLK);
  89.     outb(CLK_PORT1, (CLK_CONST / HZ) & 0xf);
  90.     outb(CLK_PORT1, (CLK_CONST / HZ) >> 8);
  91.     pic_enable_irqs(1 << IRQ_CLK);
  92. }
  93.  
  94. #define LOOPS 150000
  95. #define SHIFT 11
  96. void i8254_calibrate_delay_loop(void)
  97. {
  98.     uint64_t clk1, clk2;
  99.     uint32_t t1, t2, o1, o2;
  100.     uint8_t not_ok;
  101.  
  102.  
  103.     /*
  104.      * One-shot timer. Count-down from 0xffff at 1193180Hz
  105.      * MAGIC_NUMBER is the magic value for 1ms.
  106.      */
  107.     outb(CLK_PORT4, 0x30);
  108.     outb(CLK_PORT1, 0xff);
  109.     outb(CLK_PORT1, 0xff);
  110.  
  111.     do {
  112.         /* will read both status and count */
  113.         outb(CLK_PORT4, 0xc2);
  114.         not_ok = (inb(CLK_PORT1)>>6)&1;
  115.         t1 = inb(CLK_PORT1);
  116.         t1 |= inb(CLK_PORT1) << 8;
  117.     } while (not_ok);
  118.  
  119.     asm_delay_loop(LOOPS);
  120.  
  121.     outb(CLK_PORT4, 0xd2);
  122.     t2 = inb(CLK_PORT1);
  123.     t2 |= inb(CLK_PORT1) << 8;
  124.  
  125.     /*
  126.      * We want to determine the overhead of the calibrating mechanism.
  127.      */
  128.     outb(CLK_PORT4, 0xd2);
  129.     o1 = inb(CLK_PORT1);
  130.     o1 |= inb(CLK_PORT1) << 8;
  131.  
  132.     asm_fake_loop(LOOPS);
  133.  
  134.     outb(CLK_PORT4, 0xd2);
  135.     o2 = inb(CLK_PORT1);
  136.     o2 |= inb(CLK_PORT1) << 8;
  137.  
  138.     CPU->delay_loop_const = ((MAGIC_NUMBER*LOOPS)/1000) / ((t1-t2)-(o1-o2)) + (((MAGIC_NUMBER*LOOPS)/1000) % ((t1-t2)-(o1-o2)) ? 1 : 0);
  139.  
  140.     clk1 = rdtsc();
  141.     delay(1<<SHIFT);
  142.     clk2 = rdtsc();
  143.    
  144.     CPU->frequency_mhz = (clk2-clk1)>>SHIFT;
  145.  
  146.     return;
  147. }
  148.  
  149. /** @}
  150.  */
  151.