1 /* 2 * Copyright 2008, Dustin Howett, dustin.howett@gmail.com. All rights reserved. 3 * Distributed under the terms of the MIT License. 4 */ 5 #ifndef _KERNEL_ARCH_x86_TIMERS_PIT_H 6 #define _KERNEL_ARCH_x86_TIMERS_PIT_H 7 8 #include <SupportDefs.h> 9 10 /* ports */ 11 #define PIT_CTRL 0x43 12 #define PIT_CNT0 0x40 13 #define PIT_CNT1 0x41 14 #define PIT_CNT2 0x42 15 16 /* commands */ 17 #define PIT_SELCH0 0x00 18 #define PIT_SELCH1 0x40 19 #define PIT_SELCH2 0x80 20 21 #define PIT_RWLOW 0x10 22 #define PIT_RWHIGH 0x20 23 #define PIT_RWBOTH 0x30 24 25 #define PIT_MD_INTON0 0x00 26 #define PIT_MD_ONESHOT 0x02 27 #define PIT_MD_RTGEN 0x04 28 #define PIT_MD_SQGEN 0x06 29 #define PIT_MD_SW_STRB 0x08 30 #define PIT_MD_HW_STRB 0x0A 31 32 #define PIT_BCD 0x01 33 34 #define PIT_LATCH 0x00 35 36 #define PIT_READ 0xF0 37 #define PIT_CNT 0x20 38 #define PIT_STAT 0x10 39 40 #define PIT_CLOCK_RATE 1193180 41 #define PIT_MAX_TIMER_INTERVAL (0xffff * 1000000ll / PIT_CLOCK_RATE) 42 43 /* Method Prototypes */ 44 static int pit_get_prio(void); 45 static status_t pit_set_hardware_timer(bigtime_t relativeTimeout); 46 static status_t pit_clear_hardware_timer(void); 47 static status_t pit_init(struct kernel_args *args); 48 49 #endif /* _KERNEL_ARCH_x86_TIMERS_PIT_H */ 50