[ARM] 4261/1: clockevent support for Versatile platform

Update Versatile platform to use new clockevent infrastructure.

Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

2 files changed, 59 insertions, 10 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index cddd054676c0..d1f24aa89deb 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -167,6 +167,7 @@ config ARCH_VERSATILE
         select ARM_VIC
         select ICST307
         select GENERIC_TIME
+        select GENERIC_CLOCKEVENTS
         help
           This enables support for ARM Ltd Versatile board.
 
diff --git a/arch/arm/mach-versatile/core.c b/arch/arm/mach-versatile/core.c
index 08a9fe6eeadb..1275aa7d2eb1 100644
--- a/arch/arm/mach-versatile/core.c
+++ b/arch/arm/mach-versatile/core.c
@@ -27,6 +27,7 @@
 #include <linux/amba/bus.h>
 #include <linux/amba/clcd.h>
 #include <linux/clocksource.h>
+#include <linux/clockchips.h>
 
 #include <asm/cnt32_to_63.h>
 #include <asm/system.h>
@@ -829,19 +830,61 @@ void __init versatile_init(void)
 #define TICKS2USECS(x)  ((x) / TICKS_PER_uSEC)
 #endif
 
+static void timer_set_mode(enum clock_event_mode mode,
+                           struct clock_event_device *clk)
+{
+        unsigned long ctrl;
+
+        switch(mode) {
+        case CLOCK_EVT_MODE_PERIODIC:
+                writel(TIMER_RELOAD, TIMER0_VA_BASE + TIMER_LOAD);
+
+                ctrl = TIMER_CTRL_PERIODIC;
+                ctrl |= TIMER_CTRL_32BIT | TIMER_CTRL_IE | TIMER_CTRL_ENABLE;
+                break;
+        case CLOCK_EVT_MODE_ONESHOT:
+                /* period set, and timer enabled in 'next_event' hook */
+                ctrl = TIMER_CTRL_ONESHOT;
+                ctrl |= TIMER_CTRL_32BIT | TIMER_CTRL_IE;
+                break;
+        case CLOCK_EVT_MODE_UNUSED:
+        case CLOCK_EVT_MODE_SHUTDOWN:
+        default:
+                ctrl = 0;
+        }
+
+        writel(ctrl, TIMER0_VA_BASE + TIMER_CTRL);
+}
+
+static int timer_set_next_event(unsigned long evt,
+                                struct clock_event_device *unused)
+{
+        unsigned long ctrl = readl(TIMER0_VA_BASE + TIMER_CTRL);
+
+        writel(evt, TIMER0_VA_BASE + TIMER_LOAD);
+        writel(ctrl | TIMER_CTRL_ENABLE, TIMER0_VA_BASE + TIMER_CTRL);
+
+        return 0;
+}
+
+static struct clock_event_device timer0_clockevent =     {
+        .name           = "timer0",
+        .shift          = 32,
+        .features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+        .set_mode       = timer_set_mode,
+        .set_next_event = timer_set_next_event,
+};
+
 /*
  * IRQ handler for the timer
  */
 static irqreturn_t versatile_timer_interrupt(int irq, void *dev_id)
 {
-        write_seqlock(&xtime_lock);
+        struct clock_event_device *evt = &timer0_clockevent;
 
-        // ...clear the interrupt
         writel(1, TIMER0_VA_BASE + TIMER_INTCLR);
 
-        timer_tick();
-
-        write_sequnlock(&xtime_lock);
+        evt->event_handler(evt);
 
         return IRQ_HANDLED;
 }
@@ -909,17 +952,22 @@ static void __init versatile_timer_init(void)
         writel(0, TIMER2_VA_BASE + TIMER_CTRL);
         writel(0, TIMER3_VA_BASE + TIMER_CTRL);
 
-        writel(TIMER_RELOAD, TIMER0_VA_BASE + TIMER_LOAD);
-        writel(TIMER_RELOAD, TIMER0_VA_BASE + TIMER_VALUE);
-        writel(TIMER_DIVISOR | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC |
-               TIMER_CTRL_IE, TIMER0_VA_BASE + TIMER_CTRL);
-
         /* 
          * Make irqs happen for the system timer
          */
         setup_irq(IRQ_TIMERINT0_1, &versatile_timer_irq);
 
         versatile_clocksource_init();
+
+        timer0_clockevent.mult =
+                div_sc(1000000, NSEC_PER_SEC, timer0_clockevent.shift);
+        timer0_clockevent.max_delta_ns =
+                clockevent_delta2ns(0xffffffff, &timer0_clockevent);
+        timer0_clockevent.min_delta_ns =
+                clockevent_delta2ns(0xf, &timer0_clockevent);
+
+        timer0_clockevent.cpumask = cpumask_of_cpu(0);
+        clockevents_register_device(&timer0_clockevent);
 }
 
 struct sys_timer versatile_timer = {