Immediate counter re-load on setting (or on starting to run with) counter = 0 is a wrong behaviour for some of the timers. Add "no immediate reload" policy that provides correct behaviour for such timers. Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Message-id: bf9385cd2550ca451d564fa46007688cee3f3d9d.1475421224.git.digetx@gmail.com Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
78 lines
2.9 KiB
C
78 lines
2.9 KiB
C
/*
|
|
* General purpose implementation of a simple periodic countdown timer.
|
|
*
|
|
* Copyright (c) 2007 CodeSourcery.
|
|
*
|
|
* This code is licensed under the GNU LGPL.
|
|
*/
|
|
#ifndef PTIMER_H
|
|
#define PTIMER_H
|
|
|
|
#include "qemu-common.h"
|
|
#include "qemu/timer.h"
|
|
#include "migration/vmstate.h"
|
|
|
|
/* The default ptimer policy retains backward compatibility with the legacy
|
|
* timers. Custom policies are adjusting the default one. Consider providing
|
|
* a correct policy for your timer.
|
|
*
|
|
* The rough edges of the default policy:
|
|
* - Starting to run with a period = 0 emits error message and stops the
|
|
* timer without a trigger.
|
|
*
|
|
* - Setting period to 0 of the running timer emits error message and
|
|
* stops the timer without a trigger.
|
|
*
|
|
* - Starting to run with counter = 0 or setting it to "0" while timer
|
|
* is running causes a trigger and reloads counter with a limit value.
|
|
* If limit = 0, ptimer emits error message and stops the timer.
|
|
*
|
|
* - Counter value of the running timer is one less than the actual value.
|
|
*
|
|
* - Changing period/frequency of the running timer loses time elapsed
|
|
* since the last period, effectively restarting the timer with a
|
|
* counter = counter value at the moment of change (.i.e. one less).
|
|
*/
|
|
#define PTIMER_POLICY_DEFAULT 0
|
|
|
|
/* Periodic timer counter stays with "0" for a one period before wrapping
|
|
* around. */
|
|
#define PTIMER_POLICY_WRAP_AFTER_ONE_PERIOD (1 << 0)
|
|
|
|
/* Running periodic timer that has counter = limit = 0 would continuously
|
|
* re-trigger every period. */
|
|
#define PTIMER_POLICY_CONTINUOUS_TRIGGER (1 << 1)
|
|
|
|
/* Starting to run with/setting counter to "0" won't trigger immediately,
|
|
* but after a one period for both oneshot and periodic modes. */
|
|
#define PTIMER_POLICY_NO_IMMEDIATE_TRIGGER (1 << 2)
|
|
|
|
/* Starting to run with/setting counter to "0" won't re-load counter
|
|
* immediately, but after a one period. */
|
|
#define PTIMER_POLICY_NO_IMMEDIATE_RELOAD (1 << 3)
|
|
|
|
/* ptimer.c */
|
|
typedef struct ptimer_state ptimer_state;
|
|
typedef void (*ptimer_cb)(void *opaque);
|
|
|
|
ptimer_state *ptimer_init(QEMUBH *bh, uint8_t policy_mask);
|
|
void ptimer_set_period(ptimer_state *s, int64_t period);
|
|
void ptimer_set_freq(ptimer_state *s, uint32_t freq);
|
|
uint64_t ptimer_get_limit(ptimer_state *s);
|
|
void ptimer_set_limit(ptimer_state *s, uint64_t limit, int reload);
|
|
uint64_t ptimer_get_count(ptimer_state *s);
|
|
void ptimer_set_count(ptimer_state *s, uint64_t count);
|
|
void ptimer_run(ptimer_state *s, int oneshot);
|
|
void ptimer_stop(ptimer_state *s);
|
|
|
|
extern const VMStateDescription vmstate_ptimer;
|
|
|
|
#define VMSTATE_PTIMER(_field, _state) \
|
|
VMSTATE_STRUCT_POINTER_V(_field, _state, 1, vmstate_ptimer, ptimer_state)
|
|
|
|
#define VMSTATE_PTIMER_ARRAY(_f, _s, _n) \
|
|
VMSTATE_ARRAY_OF_POINTER_TO_STRUCT(_f, _s, _n, 0, \
|
|
vmstate_ptimer, ptimer_state)
|
|
|
|
#endif
|