Linux内核--wakeup_source机制流程简介_linux wakesource

timer.c

static void do_init_timer(struct timer_list *timer,
void (*func)(struct timer_list *),
unsigned int flags,
const char *name, struct lock_class_key *key)
{
timer->entry.pprev = NULL;
timer->function = func;
timer->flags = flags | raw_smp_processor_id();
lockdep_init_map(&timer->lockdep_map, name, key, 0);
}

/**

• init_timer_key - initialize a timer
• @timer: the timer to be initialized
• @func: timer callback function
• @flags: timer flags
• @name: name of the timer
• @key: lockdep class key of the fake lock used for tracking timer

•   sync lock dependencies
  1

• init_timer_key() must be done to a timer prior calling any of the
• other timer functions.
  */
  void init_timer_key(struct timer_list *timer,
  void (*func)(struct timer_list *), unsigned int flags,
  const char *name, struct lock_class_key *key)
  {
  debug_init(timer);
  do_init_timer(timer, func, flags, name, key);
  }
  EXPORT_SYMBOL(init_timer_key);

timer.h

#define __init_timer(_timer, _fn, _flags)
do {
static struct lock_class_key __key;
init_timer_key((_timer), (_fn), (_flags), #_timer, &__key);
} while (0)

/**

• timer_setup - prepare a timer for first use
• @timer: the timer in question
• @callback: the function to call when timer expires
• @flags: any TIMER_* flags
• Regular timer initialization should use either DEFINE_TIMER() above,
• or timer_setup(). For timers on the stack, timer_setup_on_stack() must
• be used and must be balanced with a call to destroy_timer_on_stack().
  */
  #define timer_setup(timer, callback, flags)
  __init_timer((timer), (callback), (flags))

wake_stats.c

/**

• wakeup_source_sysfs_add - Add wakeup_source attributes to sysfs.

• @parent: Device given wakeup source is associated with (or NULL if virtual).

• @ws: Wakeup source to be added in sysfs.
  */
  int wakeup_source_sysfs_add(struct device *parent, struct wakeup_source *ws)
  {
  struct device *dev;

  dev = wakeup_source_device_create(parent, ws);
  if (IS_ERR(dev))
  return PTR_ERR(dev);
  ws->dev = dev;

  return 0;
  }

wakeup.c
/**

• wakeup_source_create - Create a struct wakeup_source object.

• @name: Name of the new wakeup source.
  */
  struct wakeup_source *wakeup_source_create(const char *name)
  {
  struct wakeup_source *ws;
  const char *ws_name;
  int id;

  ws = kzalloc(sizeof(*ws), GFP_KERNEL);
  if (!ws)
  goto err_ws;

  ws_name = kstrdup_const(name, GFP_KERNEL);
  if (!ws_name)
  goto err_name;
  ws->name = ws_name;