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Commit 8eda41b0 authored by Viresh Kumar's avatar Viresh Kumar Committed by Daniel Lezcano
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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: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
parent 73766340

arch/x86/kernel/i8253.c

+1 −1
Original line number Diff line number Diff line
@@ -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();

drivers/clocksource/i8253.c

+38 −39
Original line number Diff line number Diff line
@@ -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)

{

	raw_spin_lock(&i8253_lock);

	if (!clockevent_state_oneshot(evt) && !clockevent_state_periodic(evt))

		return 0;



	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;

	raw_spin_lock(&i8253_lock);



	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);



	raw_spin_unlock(&i8253_lock);

	return 0;

}

		break;



	case CLOCK_EVT_MODE_ONESHOT:

		/* One shot setup */

static int pit_set_oneshot(struct clock_event_device *evt)

{

	raw_spin_lock(&i8253_lock);

	outb_p(0x38, PIT_MODE);

		break;



	case CLOCK_EVT_MODE_RESUME:

		/* Nothing to do here */

		break;

	raw_spin_unlock(&i8253_lock);

	return 0;

}



static int pit_set_periodic(struct clock_event_device *evt)

{

	raw_spin_lock(&i8253_lock);



	/* 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 */



	raw_spin_unlock(&i8253_lock);

	return 0;

}



/*
@@ -162,7 +158,8 @@ static int pit_next_event(unsigned long delta, struct clock_event_device *evt) 
struct clock_event_device i8253_clockevent = {

	.name			= "pit",

	.features		= CLOCK_EVT_FEAT_PERIODIC,

	.set_mode	= init_pit_timer,

	.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.