timers: Improve alarmtimer comments and minor fixes

This patch addresses a number of minor comment improvements and
other minor issues from Thomas' review of the alarmtimers code.

CC: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
This commit is contained in:
John Stultz 2011-04-28 12:58:11 -07:00
parent 9a7adcf5c6
commit 180bf812ce
2 changed files with 38 additions and 41 deletions

View File

@ -13,12 +13,22 @@ enum alarmtimer_type {
ALARM_NUMTYPE,
};
/**
* struct alarm - Alarm timer structure
* @node: timerqueue node for adding to the event list this value
* also includes the expiration time.
* @period: Period for recuring alarms
* @function: Function pointer to be executed when the timer fires.
* @type: Alarm type (BOOTTIME/REALTIME)
* @enabled: Flag that represents if the alarm is set to fire or not
* @data: Internal data value.
*/
struct alarm {
struct timerqueue_node node;
ktime_t period;
void (*function)(struct alarm *);
enum alarmtimer_type type;
char enabled;
bool enabled;
void *data;
};

View File

@ -26,7 +26,15 @@
#include <linux/workqueue.h>
#include <linux/freezer.h>
/**
* struct alarm_base - Alarm timer bases
* @lock: Lock for syncrhonized access to the base
* @timerqueue: Timerqueue head managing the list of events
* @timer: hrtimer used to schedule events while running
* @gettime: Function to read the time correlating to the base
* @base_clockid: clockid for the base
* @irqwork Delayed work structure for expiring timers
*/
static struct alarm_base {
spinlock_t lock;
struct timerqueue_head timerqueue;
@ -36,18 +44,16 @@ static struct alarm_base {
struct work_struct irqwork;
} alarm_bases[ALARM_NUMTYPE];
/* rtc timer and device for setting alarm wakeups at suspend */
static struct rtc_timer rtctimer;
static struct rtc_device *rtcdev;
/* freezer delta & lock used to handle clock_nanosleep triggered wakeups */
static ktime_t freezer_delta;
static DEFINE_SPINLOCK(freezer_delta_lock);
/**************************************************************************
* alarmtimer management code
*/
/*
/**
* alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue
* @base: pointer to the base where the timer is being run
* @alarm: pointer to alarm being enqueued.
@ -67,7 +73,7 @@ static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm)
}
}
/*
/**
* alarmtimer_remove - Removes an alarm timer from an alarm_base timerqueue
* @base: pointer to the base where the timer is running
* @alarm: pointer to alarm being removed
@ -91,16 +97,16 @@ static void alarmtimer_remove(struct alarm_base *base, struct alarm *alarm)
}
}
/*
/**
* alarmtimer_do_work - Handles alarm being fired.
* @work: pointer to workqueue being run
*
* When a timer fires, this runs through the timerqueue to see
* which alarm timers, and run those that expired. If there are
* more alarm timers queued, we set the hrtimer to fire in the
* future.
* When a alarm timer fires, this runs through the timerqueue to
* see which alarms expired, and runs those. If there are more alarm
* timers queued for the future, we set the hrtimer to fire when
* when the next future alarm timer expires.
*/
void alarmtimer_do_work(struct work_struct *work)
static void alarmtimer_do_work(struct work_struct *work)
{
struct alarm_base *base = container_of(work, struct alarm_base,
irqwork);
@ -141,7 +147,7 @@ void alarmtimer_do_work(struct work_struct *work)
}
/*
/**
* alarmtimer_fired - Handles alarm hrtimer being fired.
* @timer: pointer to hrtimer being run
*
@ -156,7 +162,7 @@ static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer)
}
/*
/**
* alarmtimer_suspend - Suspend time callback
* @dev: unused
* @state: unused
@ -230,17 +236,11 @@ static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
}
/**************************************************************************
* alarm kernel interface code
*/
/*
/**
* alarm_init - Initialize an alarm structure
* @alarm: ptr to alarm to be initialized
* @type: the type of the alarm
* @function: callback that is run when the alarm fires
*
* In-kernel interface to initializes the alarm structure.
*/
void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
void (*function)(struct alarm *))
@ -252,13 +252,11 @@ void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
alarm->enabled = 0;
}
/*
/**
* alarm_start - Sets an alarm to fire
* @alarm: ptr to alarm to set
* @start: time to run the alarm
* @period: period at which the alarm will recur
*
* In-kernel interface set an alarm timer.
*/
void alarm_start(struct alarm *alarm, ktime_t start, ktime_t period)
{
@ -275,11 +273,9 @@ void alarm_start(struct alarm *alarm, ktime_t start, ktime_t period)
spin_unlock_irqrestore(&base->lock, flags);
}
/*
/**
* alarm_cancel - Tries to cancel an alarm timer
* @alarm: ptr to alarm to be canceled
*
* In-kernel interface to cancel an alarm timer.
*/
void alarm_cancel(struct alarm *alarm)
{
@ -294,15 +290,9 @@ void alarm_cancel(struct alarm *alarm)
}
/**************************************************************************
* alarm posix interface code
*/
/*
/**
* clock2alarm - helper that converts from clockid to alarmtypes
* @clockid: clockid.
*
* Helper function that converts from clockids to alarmtypes
*/
static enum alarmtimer_type clock2alarm(clockid_t clockid)
{
@ -313,7 +303,7 @@ static enum alarmtimer_type clock2alarm(clockid_t clockid)
return -1;
}
/*
/**
* alarm_handle_timer - Callback for posix timers
* @alarm: alarm that fired
*
@ -327,7 +317,7 @@ static void alarm_handle_timer(struct alarm *alarm)
ptr->it_overrun++;
}
/*
/**
* alarm_clock_getres - posix getres interface
* @which_clock: clockid
* @tp: timespec to fill
@ -598,9 +588,6 @@ out:
return ret;
}
/**************************************************************************
* alarmtimer initialization code
*/
/* Suspend hook structures */
static const struct dev_pm_ops alarmtimer_pm_ops = {