| 1 | /* Defines for routines to implement a low-overhead timer for drivers */
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| 2 |
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| 3 | /*
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| 4 | * This program is free software; you can redistribute it and/or
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| 5 | * modify it under the terms of the GNU General Public License as
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| 6 | * published by the Free Software Foundation; either version 2, or (at
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| 7 | * your option) any later version.
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| 8 | */
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| 9 |
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| 10 | #ifndef TIMER_H
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| 11 | #define TIMER_H
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| 12 |
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| 13 | /* Ports for the 8254 timer chip */
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| 14 | #define TIMER2_PORT 0x42
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| 15 | #define TIMER_MODE_PORT 0x43
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| 16 |
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| 17 | /* Meaning of the mode bits */
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| 18 | #define TIMER0_SEL 0x00
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| 19 | #define TIMER1_SEL 0x40
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| 20 | #define TIMER2_SEL 0x80
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| 21 | #define READBACK_SEL 0xC0
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| 22 |
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| 23 | #define LATCH_COUNT 0x00
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| 24 | #define LOBYTE_ACCESS 0x10
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| 25 | #define HIBYTE_ACCESS 0x20
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| 26 | #define WORD_ACCESS 0x30
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| 27 |
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| 28 | #define MODE0 0x00
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| 29 | #define MODE1 0x02
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| 30 | #define MODE2 0x04
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| 31 | #define MODE3 0x06
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| 32 | #define MODE4 0x08
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| 33 | #define MODE5 0x0A
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| 34 |
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| 35 | #define BINARY_COUNT 0x00
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| 36 | #define BCD_COUNT 0x01
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| 37 |
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| 38 | /* Timers tick over at this rate */
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| 39 | #define CLOCK_TICK_RATE 1193180U
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| 40 | #define TICKS_PER_MS (CLOCK_TICK_RATE/1000)
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| 41 |
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| 42 | /* Parallel Peripheral Controller Port B */
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| 43 | #define PPC_PORTB 0x61
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| 44 |
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| 45 | /* Meaning of the port bits */
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| 46 | #define PPCB_T2OUT 0x20 /* Bit 5 */
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| 47 | #define PPCB_SPKR 0x02 /* Bit 1 */
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| 48 | #define PPCB_T2GATE 0x01 /* Bit 0 */
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| 49 |
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| 50 | /* Ticks must be between 0 and 65535 (0 == 65536)
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| 51 | because it is a 16 bit counter */
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| 52 | extern void load_timer2(unsigned int ticks);
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| 53 | extern inline int timer2_running(void);
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| 54 | extern void waiton_timer2(unsigned int ticks);
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| 55 |
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| 56 | extern void setup_timers(void);
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| 57 | extern void ndelay(unsigned int nsecs);
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| 58 | extern void udelay(unsigned int usecs);
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| 59 | extern void mdelay(unsigned int msecs);
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| 60 |
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| 61 |
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| 62 | #endif /* TIMER_H */
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