x86/lguest/timer: Migrate to new set-state interface

Migrate lguest 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.

We weren't doing anything while switching modes other than in shutdown
mode and so those are not implemented.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-and-tested-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: linaro-kernel@lists.linaro.org
Cc: Alexander Kuleshov <kuleshovmail@gmail.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: lguest@lists.ozlabs.org (open list:LGUEST)
Link: http://lkml.kernel.org/r/b96f1c308f4523255c5394a4e6e13f2b67685402.1437042675.git.viresh.kumar@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/lguest/boot.c

@@ -985,31 +985,19 @@ static int lguest_clockevent_set_next_event(unsigned long delta,
 	return 0;
 }
 
-static void lguest_clockevent_set_mode(enum clock_event_mode mode,
-                                      struct clock_event_device *evt)
-{
-	switch (mode) {
-	case CLOCK_EVT_MODE_UNUSED:
-	case CLOCK_EVT_MODE_SHUTDOWN:
-		/* A 0 argument shuts the clock down. */
-		hcall(LHCALL_SET_CLOCKEVENT, 0, 0, 0, 0);
-		break;
-	case CLOCK_EVT_MODE_ONESHOT:
-		/* This is what we expect. */
-		break;
-	case CLOCK_EVT_MODE_PERIODIC:
-		BUG();
-	case CLOCK_EVT_MODE_RESUME:
-		break;
-	}
+static int lguest_clockevent_shutdown(struct clock_event_device *evt)
+{
+	/* A 0 argument shuts the clock down. */
+	hcall(LHCALL_SET_CLOCKEVENT, 0, 0, 0, 0);
+	return 0;
 }
 
 /* This describes our primitive timer chip. */
 static struct clock_event_device lguest_clockevent = {
 	.name                   = "lguest",
 	.features               = CLOCK_EVT_FEAT_ONESHOT,
 	.set_next_event         = lguest_clockevent_set_next_event,
-	.set_mode               = lguest_clockevent_set_mode,
+	.set_state_shutdown	= lguest_clockevent_shutdown,
 	.rating                 = INT_MAX,
 	.mult                   = 1,
 	.shift                  = 0,