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/* Copyright 2012 The ChromiumOS Authors
* 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 */
#ifndef __CROS_EC_TIMER_H
#define __CROS_EC_TIMER_H
#include "common.h"
#include "task_id.h"
/* Time units in microseconds */
#define MSEC 1000
#define SECOND 1000000
#define SEC_UL 1000000ul
#define MINUTE 60000000
#define HOUR 3600000000ull /* Too big to fit in a signed int */
/* Microsecond timestamp. */
typedef union {
uint64_t val;
struct {
uint32_t lo;
uint32_t hi;
} le /* little endian words */;
} timestamp_t;
/* Data type for POSIX style clock() implementation */
typedef long clock_t;
/**
* Initialize the timer module.
*/
void timer_init(void);
/**
* Launch a one-shot timer for a task.
*
* Note that each task can have only a single active timer.
*
* @param tstamp Expiration timestamp for timer
* @param tskid Task to set timer for
*
* @return EC_SUCCESS, or non-zero if error.
*/
int timer_arm(timestamp_t tstamp, task_id_t tskid);
/**
* Cancel a running timer for the specified task id.
*/
void timer_cancel(task_id_t tskid);
/**
* Check if a timestamp has passed / expired
*
* @param deadline deadline timer value to check
* @param now pointer to value of time_now() if known, else NULL
* @return 0 if deadline has not yet passed, 1 if it has passed
*/
int timestamp_expired(timestamp_t deadline, const timestamp_t *now);
/**
* Busy-wait.
*
* This may be called with interrupts disabled, at any time after timer_init()
* has been called.
*
* Note that calling this with us>1000 may impact system performance; use
* usleep() for longer delays.
*
* @param us Number of microseconds to delay.
*/
void udelay(unsigned us);
/**
* Sleep.
*
* The current task will be de-scheduled for at least the specified delay (and
* perhaps longer, if a higher-priority task is running when the delay
* expires).
*
* This may only be called from a task function, with interrupts enabled.
*
* @param us Number of microseconds to sleep.
*/
void usleep(unsigned us);
/**
* Sleep for milliseconds.
*
* Otherwise the same as usleep().
*
* @param ms Number of milliseconds to sleep.
*/
static inline void msleep(unsigned ms)
{
usleep(ms * MSEC);
}
/**
* Sleep for seconds
*
* Otherwise the same as usleep().
*
* @param sec Number of seconds to sleep.
*/
static inline void sleep(unsigned sec)
{
usleep(sec * SECOND);
}
/**
* Get the current timestamp from the system timer.
*/
timestamp_t get_time(void);
/**
* Force the current value of the system timer.
*
* This function is for the power management implementation which wants to fix
* the system time when waking up from a mode with clocks turned off.
*
* Note: must be called with interrupts disabled.
*/
void force_time(timestamp_t ts);
/**
* Print the current timer information using the command output channel.
*
* This may be called from interrupt level.
*/
void timer_print_info(void);
/**
* Returns a free running millisecond clock counter, which matches tpm2
* library expectations.
*/
clock_t clock(void);
/**
* Compute how far to_time is from from_time with rollover taken into account
*
* Return us until to_time given from_time, if negative then to_time has
* passeed from_time.
*/
static inline int time_until(uint32_t from_time, uint32_t to_time)
{
return (int32_t)(to_time - from_time);
}
/**
* Returns the number of microseconds that have elapsed from a start time.
*
* This function is for timing short delays typically of a few milliseconds
* or so.
*
* Note that this is limited to a maximum of 32 bits, which is around an
* hour. After that, the value returned will wrap.
*
* @param start Start time to compare against
* @return number of microseconds that have elapsed since that start time
*/
static inline unsigned time_since32(timestamp_t start)
{
return time_until(start.le.lo, get_time().le.lo);
}
/**
* To compare time and deal with rollover
*
* Return true if a is after b.
*/
static inline int time_after(uint32_t a, uint32_t b)
{
return time_until(a, b) < 0;
}
#endif /* __CROS_EC_TIMER_H */
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