148 lines
3.2 KiB
C
148 lines
3.2 KiB
C
/*
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* Copyright (C) 2011 Apple Inc. All rights reserved.
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*
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* This document is the property of Apple Inc.
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* It is considered confidential and proprietary.
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*
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* This document may not be reproduced or transmitted in any form,
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* in whole or in part, without the express written permission of
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* Apple Inc.
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*/
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#include <arch.h>
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#include <debug.h>
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#include <platform.h>
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#include <platform/soc/hwclocks.h>
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#include <platform/timer.h>
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extern void arm_write_cntp_ctl(uint64_t);
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extern uint64_t arm_read_cntp_ctl();
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extern void arm_write_cntp_tval(uint64_t);
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extern uint64_t arm_read_cntpct();
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static void timer_deadline(void *arg);
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static void (* timer_deadline_func)(void);
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#define DECR_MAX_COUNT (INT32_MAX)
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int timer_init(uint32_t timer)
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{
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uint64_t val;
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val = (0<<0) | (1<<1);
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arm_write_cntp_ctl(val);
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return 0;
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}
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void timer_stop_all(void)
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{
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uint64_t val;
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val = (0<<0) | (1<<1);
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arm_write_cntp_ctl(val);
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}
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void timer_deadline_enter(uint64_t deadline, void (* func)(void))
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{
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uint64_t ticks;
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uint64_t decr;
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uint64_t val;
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timer_deadline_func = func;
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if (func) {
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/* convert absolute deadline to relative time */
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ticks = timer_get_ticks();
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if (deadline < ticks) {
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// printf(" %llu too soon (it is now %llu)\n", deadline, ticks);
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deadline = 0;
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} else {
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deadline -= ticks;
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}
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/* clamp the deadline to our maximum */
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decr = (deadline >= DECR_MAX_COUNT) ? DECR_MAX_COUNT : deadline;
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// printf(" using decrementer count %u\n", decr);
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/*
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* Reset the decrementer by programming the max count, clearing
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* any pending interrupt status, then programming the desired count.
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* Note the timer's value is a signed 32 bit number
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*/
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arm_write_cntp_tval(DECR_MAX_COUNT);
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val = (1<<0) | (0<<1);
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arm_write_cntp_ctl(val);
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arm_write_cntp_tval(decr);
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} else {
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/* no deadline, disable the decrementer */
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val = (0<<0) | (1<<1);
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arm_write_cntp_ctl(val);
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}
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}
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void arm_fiq()
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{
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uint64_t val;
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_irq_enter_critical_section();
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val = arm_read_cntp_ctl();
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if (val & (1 << 2)) {
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/* acknowledge the interrupt and disable the timer */
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val = (0<<0) | (1<<1);
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arm_write_cntp_ctl(val);
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/* if we have a callback, invoke it now */
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if (timer_deadline_func)
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timer_deadline_func();
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}
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_irq_exit_critical_section();
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}
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#ifdef OSC_FREQ
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utime_t timer_ticks_to_usecs(uint64_t ticks)
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{
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#if (OSC_FREQ % 1000000) == 0
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return ticks / (OSC_FREQ / 1000000);
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#else
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#error "The code below has overflow issues. Make sure you really want to use it"
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return (ticks * 1000 * 1000) / OSC_FREQ;
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#endif
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}
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uint64_t timer_usecs_to_ticks(utime_t usecs)
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{
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#if (OSC_FREQ % 1000000) == 0
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return usecs * (OSC_FREQ / 1000000);
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#else
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#error "The code below has overflow issues. Make sure you really want to use it"
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uint64_t timer_scale = ((uint64_t)(OSC_FREQ) << 20) / (1000 * 1000);
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return (ticks * timer_scale) >> 20;
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#endif
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}
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uint32_t timer_get_tick_rate(void)
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{
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return OSC_FREQ;
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}
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#endif
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uint64_t timer_get_ticks(void)
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{
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return (arm_read_cntpct());
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}
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void arm_no_wfe_spin(uint32_t usecs)
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{
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uint64_t delta_time = (uint64_t)usecs * (OSC_FREQ / 1000000);
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uint64_t start_time;
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start_time = timer_get_ticks();
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while (true) {
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if ((timer_get_ticks() - start_time) > delta_time)
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break;
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}
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}
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