97 lines
2 KiB
C
97 lines
2 KiB
C
|
/* SPDX-License-Identifier: GPL-2.0 */
|
||
|
|
#ifndef __TRIGGER_H_
|
||
|
|
#define __TRIGGER_H_ 1
|
||
|
|
|
||
|
|
#include "util/debug.h"
|
||
|
|
#include "asm/bug.h"
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Use trigger to model operations which need to be executed when
|
||
|
|
* an event (a signal, for example) is observed.
|
||
|
|
*
|
||
|
|
* States and transits:
|
||
|
|
*
|
||
|
|
*
|
||
|
|
* OFF--> ON --> READY --(hit)--> HIT
|
||
|
|
* ^ |
|
||
|
|
* | (ready)
|
||
|
|
* | |
|
||
|
|
* \_____________/
|
||
|
|
*
|
||
|
|
* is_hit and is_ready are two key functions to query the state of
|
||
|
|
* a trigger. is_hit means the event already happen; is_ready means the
|
||
|
|
* trigger is waiting for the event.
|
||
|
|
*/
|
||
|
|
|
||
|
|
struct trigger {
|
||
|
|
volatile enum {
|
||
|
|
TRIGGER_ERROR = -2,
|
||
|
|
TRIGGER_OFF = -1,
|
||
|
|
TRIGGER_ON = 0,
|
||
|
|
TRIGGER_READY = 1,
|
||
|
|
TRIGGER_HIT = 2,
|
||
|
|
} state;
|
||
|
|
const char *name;
|
||
|
|
};
|
||
|
|
|
||
|
|
#define TRIGGER_WARN_ONCE(t, exp) \
|
||
|
|
WARN_ONCE(t->state != exp, "trigger '%s' state transist error: %d in %s()\n", \
|
||
|
|
t->name, t->state, __func__)
|
||
|
|
|
||
|
|
static inline bool trigger_is_available(struct trigger *t)
|
||
|
|
{
|
||
|
|
return t->state >= 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline bool trigger_is_error(struct trigger *t)
|
||
|
|
{
|
||
|
|
return t->state <= TRIGGER_ERROR;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void trigger_on(struct trigger *t)
|
||
|
|
{
|
||
|
|
TRIGGER_WARN_ONCE(t, TRIGGER_OFF);
|
||
|
|
t->state = TRIGGER_ON;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void trigger_ready(struct trigger *t)
|
||
|
|
{
|
||
|
|
if (!trigger_is_available(t))
|
||
|
|
return;
|
||
|
|
t->state = TRIGGER_READY;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void trigger_hit(struct trigger *t)
|
||
|
|
{
|
||
|
|
if (!trigger_is_available(t))
|
||
|
|
return;
|
||
|
|
TRIGGER_WARN_ONCE(t, TRIGGER_READY);
|
||
|
|
t->state = TRIGGER_HIT;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void trigger_off(struct trigger *t)
|
||
|
|
{
|
||
|
|
if (!trigger_is_available(t))
|
||
|
|
return;
|
||
|
|
t->state = TRIGGER_OFF;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline void trigger_error(struct trigger *t)
|
||
|
|
{
|
||
|
|
t->state = TRIGGER_ERROR;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline bool trigger_is_ready(struct trigger *t)
|
||
|
|
{
|
||
|
|
return t->state == TRIGGER_READY;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline bool trigger_is_hit(struct trigger *t)
|
||
|
|
{
|
||
|
|
return t->state == TRIGGER_HIT;
|
||
|
|
}
|
||
|
|
|
||
|
|
#define DEFINE_TRIGGER(n) \
|
||
|
|
struct trigger n = {.state = TRIGGER_OFF, .name = #n}
|
||
|
|
#endif
|