diff options
| -rw-r--r-- | include/linux/clockchips.h | 9 | ||||
| -rw-r--r-- | kernel/time/clockevents.c | 44 |
2 files changed, 53 insertions, 0 deletions
diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h index 9466eebc8e19..80acc79e0dc5 100644 --- a/include/linux/clockchips.h +++ b/include/linux/clockchips.h @@ -69,6 +69,8 @@ enum clock_event_nofitiers { * @retries: number of forced programming retries * @set_mode: set mode function * @broadcast: function to broadcast events + * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration + * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration * @name: ptr to clock event name * @rating: variable to rate clock event devices * @irq: IRQ number (only for non CPU local devices) @@ -91,6 +93,9 @@ struct clock_event_device { void (*broadcast)(const struct cpumask *mask); void (*set_mode)(enum clock_event_mode mode, struct clock_event_device *); + unsigned long min_delta_ticks; + unsigned long max_delta_ticks; + const char *name; int rating; int irq; @@ -123,6 +128,10 @@ extern u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt); extern void clockevents_register_device(struct clock_event_device *dev); +extern void clockevents_config_and_register(struct clock_event_device *dev, + u32 freq, unsigned long min_delta, + unsigned long max_delta); + extern void clockevents_exchange_device(struct clock_event_device *old, struct clock_event_device *new); extern void clockevents_set_mode(struct clock_event_device *dev, diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index 0d74b9ba90c8..c69e88c94446 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -194,6 +194,50 @@ void clockevents_register_device(struct clock_event_device *dev) } EXPORT_SYMBOL_GPL(clockevents_register_device); +static void clockevents_config(struct clock_event_device *dev, + u32 freq) +{ + unsigned long sec; + + if (!(dev->features & CLOCK_EVT_FEAT_ONESHOT)) + return; + + /* + * Calculate the maximum number of seconds we can sleep. Limit + * to 10 minutes for hardware which can program more than + * 32bit ticks so we still get reasonable conversion values. + */ + sec = dev->max_delta_ticks; + do_div(sec, freq); + if (!sec) + sec = 1; + else if (sec > 600 && dev->max_delta_ticks > UINT_MAX) + sec = 600; + + clockevents_calc_mult_shift(dev, freq, sec); + dev->min_delta_ns = clockevent_delta2ns(dev->min_delta_ticks, dev); + dev->max_delta_ns = clockevent_delta2ns(dev->max_delta_ticks, dev); +} + +/** + * clockevents_config_and_register - Configure and register a clock event device + * @dev: device to register + * @freq: The clock frequency + * @min_delta: The minimum clock ticks to program in oneshot mode + * @max_delta: The maximum clock ticks to program in oneshot mode + * + * min/max_delta can be 0 for devices which do not support oneshot mode. + */ +void clockevents_config_and_register(struct clock_event_device *dev, + u32 freq, unsigned long min_delta, + unsigned long max_delta) +{ + dev->min_delta_ticks = min_delta; + dev->max_delta_ticks = max_delta; + clockevents_config(dev, freq); + clockevents_register_device(dev); +} + /* * Noop handler when we shut down an event device */ |