1 /* Defines for routines to implement a low-overhead timer for drivers */
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2, or (at
7 * your option) any later version.
13 /* Ports for the 8254 timer chip */
14 #define TIMER2_PORT 0x42
15 #define TIMER_MODE_PORT 0x43
17 /* Meaning of the mode bits */
18 #define TIMER0_SEL 0x00
19 #define TIMER1_SEL 0x40
20 #define TIMER2_SEL 0x80
21 #define READBACK_SEL 0xC0
23 #define LATCH_COUNT 0x00
24 #define LOBYTE_ACCESS 0x10
25 #define HIBYTE_ACCESS 0x20
26 #define WORD_ACCESS 0x30
35 #define BINARY_COUNT 0x00
36 #define BCD_COUNT 0x01
38 /* Timers tick over at this rate */
39 #define CLOCK_TICK_RATE 1193180U
40 #define TICKS_PER_MS (CLOCK_TICK_RATE/1000)
42 /* Parallel Peripheral Controller Port B */
43 #define PPC_PORTB 0x61
45 /* Meaning of the port bits */
46 #define PPCB_T2OUT 0x20 /* Bit 5 */
47 #define PPCB_SPKR 0x02 /* Bit 1 */
48 #define PPCB_T2GATE 0x01 /* Bit 0 */
50 /* Ticks must be between 0 and 65535 (0 == 65536)
51 because it is a 16 bit counter */
52 extern void load_timer2(unsigned int ticks);
53 extern inline int timer2_running(void);
54 extern void waiton_timer2(unsigned int ticks);
55 extern void __load_timer2(unsigned int ticks);
57 extern void setup_timers(void);
58 extern void ndelay(unsigned int nsecs);
59 extern void udelay(unsigned int usecs);
60 extern void mdelay(unsigned int msecs);
61 extern unsigned long currticks(void);