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>

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.