[PATCH 08/41] clocksource: i8253: Migrate to new 'set-state' interface
From: viresh.kumar@linaro.org (Viresh Kumar)
Date: 2015-06-18 11:07:43
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Subsystem:
clocksource, clockevent drivers, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Daniel Lezcano, Thomas Gleixner, Linus Torvalds, Ingo Molnar, Borislav Petkov, Dave Hansen
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 <redacted> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- arch/x86/kernel/i8253.c | 2 +- drivers/clocksource/i8253.c | 77 ++++++++++++++++++++++----------------------- 2 files changed, 39 insertions(+), 40 deletions(-)
diff --git a/arch/x86/kernel/i8253.c b/arch/x86/kernel/i8253.c
index f2b96de3c7c1..efb82f07b29c 100644
--- a/arch/x86/kernel/i8253.c
+++ b/arch/x86/kernel/i8253.c@@ -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();
diff --git a/drivers/clocksource/i8253.c b/drivers/clocksource/i8253.c
index 14ee3efcc404..0efd36e483ab 100644
--- a/drivers/clocksource/i8253.c
+++ b/drivers/clocksource/i8253.c@@ -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); - 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; - - 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; - } + 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); + + /* 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; } /*
@@ -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.
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2.4.0