timer.c

Commit: e6209518 Author: jokerz Raw Copy

/* timer.c — ARM Generic Timer driver */

#include "timer.h"

#include "gic.h"

static volatile uint64_t ticks_count = 0;

void timer_init(void) {

    uint64_t freq = timer_get_freq();

    /* Set timer interval for 100Hz (freq/100 ticks per interrupt) */

    uint64_t interval = freq / 100;

    __asm__ volatile("msr cntp_tval_el0, %0" :: "r"(interval));

    /* Enable timer: unmask (bit 1=0), enable (bit 0=1) */

    __asm__ volatile("msr cntp_ctl_el0, %0" :: "r"(1UL));

    /* Enable timer IRQ on GIC */

    gic_enable_irq(IRQ_TIMER_CNTP);

}

void timer_irq(void) {

    ticks_count++;

    /* Acknowledge timer interrupt by writing new interval */

    uint64_t freq = timer_get_freq();

    __asm__ volatile("msr cntp_tval_el0, %0" :: "r"(freq / 100));

}

uint64_t timer_ticks(void) {

    return ticks_count;

}

1	/* timer.c — ARM Generic Timer driver */
2
3	#include "timer.h"
4	#include "gic.h"
5
6	static volatile uint64_t ticks_count = 0;
7
8	void timer_init(void) {
9	uint64_t freq = timer_get_freq();
10
11	/* Set timer interval for 100Hz (freq/100 ticks per interrupt) */
12	uint64_t interval = freq / 100;
13	__asm__ volatile("msr cntp_tval_el0, %0" :: "r"(interval));
14
15	/* Enable timer: unmask (bit 1=0), enable (bit 0=1) */
16	__asm__ volatile("msr cntp_ctl_el0, %0" :: "r"(1UL));
17
18	/* Enable timer IRQ on GIC */
19	gic_enable_irq(IRQ_TIMER_CNTP);
20	}
21
22	void timer_irq(void) {
23	ticks_count++;
24
25	/* Acknowledge timer interrupt by writing new interval */
26	uint64_t freq = timer_get_freq();
27	__asm__ volatile("msr cntp_tval_el0, %0" :: "r"(freq / 100));
28	}
29
30	uint64_t timer_ticks(void) {
31	return ticks_count;
32	}
33