Rev 15 | Go to most recent revision | Details | Last modification | View Log | RSS feed
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| 1 | jermar | 1 | /* |
| 2 | * Copyright (C) 2001-2004 Jakub Jermar |
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| 3 | * All rights reserved. |
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| 4 | * |
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| 5 | * Redistribution and use in source and binary forms, with or without |
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| 6 | * modification, are permitted provided that the following conditions |
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| 7 | * are met: |
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| 8 | * |
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| 9 | * - Redistributions of source code must retain the above copyright |
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| 10 | * notice, this list of conditions and the following disclaimer. |
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| 11 | * - Redistributions in binary form must reproduce the above copyright |
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| 12 | * notice, this list of conditions and the following disclaimer in the |
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| 13 | * documentation and/or other materials provided with the distribution. |
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| 14 | * - The name of the author may not be used to endorse or promote products |
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| 15 | * derived from this software without specific prior written permission. |
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| 16 | * |
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 27 | */ |
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| 28 | |||
| 29 | #include <arch/types.h> |
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| 30 | #include <time/clock.h> |
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| 31 | #include <time/delay.h> |
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| 32 | #include <arch/interrupt.h> |
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| 33 | #include <arch/i8259.h> |
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| 34 | #include <arch/i8254.h> |
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| 35 | #include <cpu.h> |
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| 36 | #include <config.h> |
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| 37 | #include <arch/pm.h> |
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| 38 | #include <arch/asm.h> |
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| 39 | #include <arch.h> |
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| 40 | |||
| 41 | /* |
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| 42 | * i8254 chip driver. |
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| 43 | * Low level time functions. |
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| 44 | */ |
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| 45 | |||
| 46 | #define CLK_PORT1 0x40 |
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| 47 | #define CLK_PORT4 0x43 |
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| 48 | |||
| 49 | |||
| 50 | #define CLK_CONST 1193180 |
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| 51 | #define MAGIC_NUMBER 1194 |
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| 52 | |||
| 53 | void i8254_init(void) |
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| 54 | { |
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| 55 | i8254_normal_operation(); |
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| 56 | } |
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| 57 | |||
| 58 | void i8254_normal_operation(void) |
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| 59 | { |
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| 60 | outb(CLK_PORT4, 0x36); |
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| 61 | trap_virtual_disable_irqs(1<<IRQ_CLK); |
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| 62 | outb(CLK_PORT1, (CLK_CONST/HZ) & 0xf); |
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| 63 | outb(CLK_PORT1, (CLK_CONST/HZ) >> 8); |
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| 64 | trap_virtual_enable_irqs(1<<IRQ_CLK); |
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| 65 | trap_register(VECTOR_CLK, i8254_interrupt); |
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| 66 | } |
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| 67 | |||
| 68 | #define LOOPS 150000 |
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| 69 | #define SHIFT 11 |
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| 70 | void i8254_calibrate_delay_loop(void) |
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| 71 | { |
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| 72 | __u64 clk1, clk2; |
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| 73 | __u32 t1, t2, o1, o2; |
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| 74 | __u8 not_ok; |
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| 75 | |||
| 76 | |||
| 77 | /* |
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| 78 | * One-shot timer. Count-down from 0xffff at 1193180Hz |
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| 79 | * MAGIC_NUMBER is the magic value for 1ms. |
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| 80 | */ |
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| 81 | outb(CLK_PORT4, 0x30); |
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| 82 | outb(CLK_PORT1, 0xff); |
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| 83 | outb(CLK_PORT1, 0xff); |
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| 84 | |||
| 85 | do { |
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| 86 | /* will read both status and count */ |
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| 87 | outb(CLK_PORT4, 0xc2); |
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| 88 | not_ok = (inb(CLK_PORT1)>>6)&1; |
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| 89 | t1 = inb(CLK_PORT1); |
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| 90 | t1 |= inb(CLK_PORT1) << 8; |
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| 91 | } while (not_ok); |
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| 92 | |||
| 93 | asm_delay_loop(LOOPS); |
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| 94 | |||
| 95 | outb(CLK_PORT4, 0xd2); |
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| 96 | t2 = inb(CLK_PORT1); |
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| 97 | t2 |= inb(CLK_PORT1) << 8; |
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| 98 | |||
| 99 | /* |
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| 100 | * We want to determine the overhead of the calibrating mechanism. |
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| 101 | */ |
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| 102 | outb(CLK_PORT4, 0xd2); |
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| 103 | o1 = inb(CLK_PORT1); |
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| 104 | o1 |= inb(CLK_PORT1) << 8; |
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| 105 | |||
| 106 | asm_fake_loop(LOOPS); |
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| 107 | |||
| 108 | outb(CLK_PORT4, 0xd2); |
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| 109 | o2 = inb(CLK_PORT1); |
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| 110 | o2 |= inb(CLK_PORT1) << 8; |
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| 111 | |||
| 112 | |||
| 113 | the->cpu->delay_loop_const = ((MAGIC_NUMBER*LOOPS)/1000) / ((t1-t2)-(o1-o2)) + |
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| 114 | (((MAGIC_NUMBER*LOOPS)/1000) % ((t1-t2)-(o1-o2)) ? 1 : 0); |
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| 115 | |||
| 116 | |||
| 117 | clk1 = rdtsc(); |
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| 118 | delay(1<<SHIFT); |
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| 119 | clk2 = rdtsc(); |
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| 120 | |||
| 121 | the->cpu->frequency_mhz = (clk2-clk1)>>SHIFT; |
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| 122 | |||
| 123 | return; |
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| 124 | } |
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| 125 | |||
| 126 | void i8254_interrupt(__u8 n, __u32 stack[]) |
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| 127 | { |
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| 128 | trap_virtual_eoi(); |
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| 129 | clock(); |
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| 130 | } |