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clockevents/drivers/i8253: Migrate to new 'set-state' interface 

Migrate i8253 driver to the new 'set-state' interface provided by
clockevents core, the earlier 'set-mode' interface is marked obsolete
now.

This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.

Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
steinar/wifi_calib_4_9_kernel
Viresh Kumar 2015-06-18 16:24:22 +05:30 committed by Daniel Lezcano
parent 7376634018
commit 8eda41b086
2 changed files with 38 additions and 39 deletions
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2
arch/x86/kernel/i8253.c
View File

@ -34,7 +34,7 @@ static int __init init_pit_clocksource(void)
* - when local APIC timer is active (PIT is switched off)
*/
if (num_possible_cpus() > 1 || is_hpet_enabled() ||
i8253_clockevent.mode != CLOCK_EVT_MODE_PERIODIC)
!clockevent_state_periodic(&i8253_clockevent))
return 0;
return clocksource_i8253_init();

75
drivers/clocksource/i8253.c
View File

@ -100,44 +100,40 @@ int __init clocksource_i8253_init(void)
#endif
#ifdef CONFIG_CLKEVT_I8253
/*
* Initialize the PIT timer.
*
* This is also called after resume to bring the PIT into operation again.
*/
static void init_pit_timer(enum clock_event_mode mode,
struct clock_event_device *evt)
static int pit_shutdown(struct clock_event_device *evt)
{
if (!clockevent_state_oneshot(evt) && !clockevent_state_periodic(evt))
return 0;
raw_spin_lock(&i8253_lock);
outb_p(0x30, PIT_MODE);
outb_p(0, PIT_CH0);
outb_p(0, PIT_CH0);
raw_spin_unlock(&i8253_lock);
return 0;
}
static int pit_set_oneshot(struct clock_event_device *evt)
{
raw_spin_lock(&i8253_lock);
outb_p(0x38, PIT_MODE);
raw_spin_unlock(&i8253_lock);
return 0;
}
static int pit_set_periodic(struct clock_event_device *evt)
{
raw_spin_lock(&i8253_lock);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
/* binary, mode 2, LSB/MSB, ch 0 */
outb_p(0x34, PIT_MODE);
outb_p(PIT_LATCH & 0xff , PIT_CH0); /* LSB */
outb_p(PIT_LATCH >> 8 , PIT_CH0); /* MSB */
break;
/* binary, mode 2, LSB/MSB, ch 0 */
outb_p(0x34, PIT_MODE);
outb_p(PIT_LATCH & 0xff, PIT_CH0); /* LSB */
outb_p(PIT_LATCH >> 8, PIT_CH0); /* MSB */
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_UNUSED:
if (evt->mode == CLOCK_EVT_MODE_PERIODIC ||
evt->mode == CLOCK_EVT_MODE_ONESHOT) {
outb_p(0x30, PIT_MODE);
outb_p(0, PIT_CH0);
outb_p(0, PIT_CH0);
}
break;
case CLOCK_EVT_MODE_ONESHOT:
/* One shot setup */
outb_p(0x38, PIT_MODE);
break;
case CLOCK_EVT_MODE_RESUME:
/* Nothing to do here */
break;
}
raw_spin_unlock(&i8253_lock);
return 0;
}
/*
@ -160,10 +156,11 @@ static int pit_next_event(unsigned long delta, struct clock_event_device *evt)
* it can be solely used for the global tick.
*/
struct clock_event_device i8253_clockevent = {
.name = "pit",
.features = CLOCK_EVT_FEAT_PERIODIC,
.set_mode = init_pit_timer,
.set_next_event = pit_next_event,
.name = "pit",
.features = CLOCK_EVT_FEAT_PERIODIC,
.set_state_shutdown = pit_shutdown,
.set_state_periodic = pit_set_periodic,
.set_next_event = pit_next_event,
};
/*
@ -172,8 +169,10 @@ struct clock_event_device i8253_clockevent = {
*/
void __init clockevent_i8253_init(bool oneshot)
{
if (oneshot)
if (oneshot) {
i8253_clockevent.features |= CLOCK_EVT_FEAT_ONESHOT;
i8253_clockevent.set_state_oneshot = pit_set_oneshot;
}
/*
* Start pit with the boot cpu mask. x86 might make it global
* when it is used as broadcast device later.