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/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* Timer module for Chrome EC operating system */
#include <stdint.h>
#include "task.h"
#include "timer.h"
#include "hwtimer.h"
#include "atomic.h"
#include "console.h"
#include "uart.h"
#include "util.h"
/* high word of the 64-bit timestamp counter */
static volatile uint32_t clksrc_high;
/* bitmap of currently running timers */
static uint32_t timer_running = 0;
/* deadlines of all timers */
static timestamp_t timer_deadline[TASK_ID_COUNT];
static uint32_t next_deadline = 0xffffffff;
/* Hardware timer routine IRQ number */
static int timer_irq;
static void expire_timer(task_id_t tskid)
{
/* we are done with this timer */
atomic_clear(&timer_running, 1<<tskid);
/* wake up the taks waiting for this timer */
task_set_event(tskid, TASK_EVENT_TIMER, 0);
}
int timestamp_expired(timestamp_t deadline)
{
timestamp_t now = get_time();
return ((int64_t)(now.val - deadline.val) >= 0);
}
void process_timers(int overflow)
{
uint32_t check_timer, running_t0;
timestamp_t next;
timestamp_t now;
if (overflow)
clksrc_high++;
do {
next.val = 0xffffffffffffffff;
now = get_time();
do {
/* read atomically the current state of timer running */
check_timer = running_t0 = timer_running;
while (check_timer) {
int tskid = 31 - __builtin_clz(check_timer);
/* timer has expired ? */
if (timer_deadline[tskid].val < now.val)
expire_timer(tskid);
else if ((timer_deadline[tskid].le.hi ==
now.le.hi) &&
(timer_deadline[tskid].le.lo <
next.le.lo))
next.val = timer_deadline[tskid].val;
check_timer &= ~(1 << tskid);
}
/* if there is a new timer, let's retry */
} while (timer_running & ~running_t0);
if (next.le.hi == 0xffffffff) {
/* no deadline to set */
__hw_clock_event_clear();
next_deadline = 0xffffffff;
return;
}
__hw_clock_event_set(next.le.lo);
next_deadline = next.le.lo;
} while (next.val <= get_time().val);
}
void udelay(unsigned us)
{
timestamp_t deadline = get_time();
deadline.val += us;
while (get_time().val < deadline.val) {}
}
int timer_arm(timestamp_t tstamp, task_id_t tskid)
{
ASSERT(tskid < TASK_ID_COUNT);
if (timer_running & (1<<tskid))
return EC_ERROR_BUSY;
timer_deadline[tskid] = tstamp;
atomic_or(&timer_running, 1<<tskid);
/* modify the next event if needed */
if ((tstamp.le.hi < clksrc_high) ||
((tstamp.le.hi == clksrc_high) && (tstamp.le.lo <= next_deadline)))
task_trigger_irq(timer_irq);
return EC_SUCCESS;
}
int timer_cancel(task_id_t tskid)
{
ASSERT(tskid < TASK_ID_COUNT);
atomic_clear(&timer_running, 1<<tskid);
/* don't bother about canceling the interrupt:
* it would be slow, just do it on the next IT
*/
return EC_SUCCESS;
}
void usleep(unsigned us)
{
uint32_t evt = 0;
ASSERT(us);
do {
evt |= task_wait_event(us);
} while (!(evt & TASK_EVENT_TIMER));
/* re-queue other events which happened in the meanwhile */
if (evt)
atomic_or(task_get_event_bitmap(task_get_current()),
evt & ~TASK_EVENT_TIMER);
}
timestamp_t get_time(void)
{
timestamp_t ts;
ts.le.hi = clksrc_high;
ts.le.lo = __hw_clock_source_read();
if (ts.le.hi != clksrc_high) {
ts.le.hi = clksrc_high;
ts.le.lo = __hw_clock_source_read();
}
return ts;
}
void timer_print_info(void)
{
uint64_t t = get_time().val;
uint64_t deadline = (uint64_t)clksrc_high << 32 |
__hw_clock_event_get();
int tskid;
ccprintf("Time: 0x%016lx us\n"
"Deadline: 0x%016lx -> %10ld us from now\n"
"Active timers:\n",
t, deadline, deadline - t);
for (tskid = 0; tskid < TASK_ID_COUNT; tskid++) {
if (timer_running & (1<<tskid)) {
ccprintf(" Tsk %2d 0x%016lx -> %10ld %x\n", tskid,
timer_deadline[tskid].val,
timer_deadline[tskid].val - t, 0xabcd);
if (in_interrupt_context())
uart_emergency_flush();
else
cflush();
}
}
}
static int command_wait(int argc, char **argv)
{
if (argc < 2)
return EC_ERROR_INVAL;
udelay(atoi(argv[1]) * 1000);
return EC_SUCCESS;
}
DECLARE_CONSOLE_COMMAND(waitms, command_wait);
static int command_get_time(int argc, char **argv)
{
timestamp_t ts = get_time();
ccprintf("Time: 0x%016lx = %ld us\n", ts.val, ts.val);
return EC_SUCCESS;
}
DECLARE_CONSOLE_COMMAND(gettime, command_get_time);
int command_timer_info(int argc, char **argv)
{
timer_print_info();
return EC_SUCCESS;
}
DECLARE_CONSOLE_COMMAND(timerinfo, command_timer_info);
int timer_init(void)
{
BUILD_ASSERT(TASK_ID_COUNT < sizeof(timer_running) * 8);
timer_irq = __hw_clock_source_init();
return EC_SUCCESS;
}
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