diff options
Diffstat (limited to 'cpu/i386/timer.c')
| -rw-r--r-- | cpu/i386/timer.c | 50 |
1 files changed, 25 insertions, 25 deletions
diff --git a/cpu/i386/timer.c b/cpu/i386/timer.c index a23cd6e..486d927 100644 --- a/cpu/i386/timer.c +++ b/cpu/i386/timer.c @@ -46,28 +46,28 @@ unsigned long get_system_ticks(void) int timer_init(void) { system_ticks = 0; - + irq_install_handler(0, timer_isr, NULL); - - /* initialize timer 0 and 2 - * + + /* initialize timer 0 and 2 + * * Timer 0 is used to increment system_tick 1000 times/sec * Timer 1 was used for DRAM refresh in early PC's * Timer 2 is used to drive the speaker * (to stasrt a beep: write 3 to port 0x61, * to stop it again: write 0) */ - - outb(PIT_CMD_CTR0|PIT_CMD_BOTH|PIT_CMD_MODE2, PIT_BASE + PIT_COMMAND); + + outb(PIT_CMD_CTR0|PIT_CMD_BOTH|PIT_CMD_MODE2, PIT_BASE + PIT_COMMAND); outb(TIMER0_VALUE&0xff, PIT_BASE + PIT_T0); outb(TIMER0_VALUE>>8, PIT_BASE + PIT_T0); - outb(PIT_CMD_CTR2|PIT_CMD_BOTH|PIT_CMD_MODE3, PIT_BASE + PIT_COMMAND); + outb(PIT_CMD_CTR2|PIT_CMD_BOTH|PIT_CMD_MODE3, PIT_BASE + PIT_COMMAND); outb(TIMER2_VALUE&0xff, PIT_BASE + PIT_T2); outb(TIMER2_VALUE>>8, PIT_BASE + PIT_T2); timer_init_done = 1; - + return 0; } @@ -87,7 +87,7 @@ ulong get_timer (ulong base) return (system_ticks - base); } -void set_timer (ulong t) +void set_timer (ulong t) { system_ticks = t; } @@ -102,20 +102,20 @@ static u16 read_pit(void) /* this is not very exact */ void udelay (unsigned long usec) -{ +{ int counter; int wraps; - + if (!timer_init_done) { return; } counter = read_pit(); wraps = usec/1000; usec = usec%1000; - + usec*=1194; usec/=1000; - usec+=counter; + usec+=counter; if (usec > 1194) { usec-=1194; wraps++; @@ -123,26 +123,26 @@ void udelay (unsigned long usec) while (1) { int new_count = read_pit(); - + if (((new_count < usec) && !wraps) || wraps < 0) { break; } - + if (new_count > counter) { wraps--; } counter = new_count; } - + } #if 0 /* this is a version with debug output */ void _udelay (unsigned long usec) -{ +{ int counter; int wraps; - + int usec1, usec2, usec3; int wraps1, wraps2, wraps3, wraps4; int ctr1, ctr2, ctr3, nct1, nct2; @@ -155,13 +155,13 @@ void _udelay (unsigned long usec) ctr1 = counter; wraps = usec/1000; usec = usec%1000; - + usec2 = usec; wraps1 = wraps; - + usec*=1194; usec/=1000; - usec+=counter; + usec+=counter; if (usec > 1194) { usec-=1194; wraps++; @@ -169,7 +169,7 @@ void _udelay (unsigned long usec) usec3 = usec; wraps2 = wraps; - + ctr2 = wraps3 = nct1 = 4711; ctr3 = wraps4 = nct2 = 4711; i=0; @@ -179,7 +179,7 @@ void _udelay (unsigned long usec) if ((new_count < usec && !wraps) || wraps < 0) { break; } - + if (new_count > counter) { wraps--; } @@ -192,10 +192,10 @@ void _udelay (unsigned long usec) wraps4 = wraps; nct2 = new_count; } - + counter = new_count; } - + printf("udelay(%d)\n", usec1); printf("counter %d\n", ctr1); printf("1: wraps %d, usec %d\n", wraps1, usec2); |