[ARM] 4812/1: RealView: clockevents support for the RealView platforms
authorCatalin Marinas <catalin.marinas@arm.com>
Mon, 4 Feb 2008 16:26:55 +0000 (17:26 +0100)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Mon, 4 Feb 2008 17:52:17 +0000 (17:52 +0000)
The patch updates the RealView code to the clockevents infrastructure.
The SMP support is implemented in subsequent patches. Based on the
Versatile implementation by Kevin Hilman.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arch/arm/Kconfig
arch/arm/mach-realview/core.c

index a2b7e4a52f73b054a7410927ff2ccb9337fb2dc3..b82828e768ad4570595a99d0f85e3f77c2e55582 100644 (file)
@@ -169,6 +169,7 @@ config ARCH_REALVIEW
        select ARM_AMBA
        select ICST307
        select GENERIC_TIME
+       select GENERIC_CLOCKEVENTS
        help
          This enables support for ARM Ltd RealView boards.
 
index f805840f6f440d24c5c68bb4d7273065b4a77e1b..6c68deed84dc1e5eae9d6670c7e5a707a6652b6c 100644 (file)
@@ -26,6 +26,7 @@
 #include <linux/amba/bus.h>
 #include <linux/amba/clcd.h>
 #include <linux/clocksource.h>
+#include <linux/clockchips.h>
 
 #include <asm/system.h>
 #include <asm/hardware.h>
@@ -485,20 +486,77 @@ void realview_leds_event(led_event_t ledevt)
 #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,
+       .rating         = 300,
+       .irq            = IRQ_TIMERINT0_1,
+       .cpumask        = CPU_MASK_ALL,
+};
+
+static void __init realview_clockevents_init(void)
+{
+       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);
+
+       clockevents_register_device(&timer0_clockevent);
+}
+
 /*
  * IRQ handler for the timer
  */
 static irqreturn_t realview_timer_interrupt(int irq, void *dev_id)
 {
-       // ...clear the interrupt
-       writel(1, TIMER0_VA_BASE + TIMER_INTCLR);
+       struct clock_event_device *evt = &timer0_clockevent;
 
-       timer_tick();
+       /* clear the interrupt */
+       writel(1, TIMER0_VA_BASE + TIMER_INTCLR);
 
-#if defined(CONFIG_SMP) && !defined(CONFIG_LOCAL_TIMERS)
-       smp_send_timer();
-       update_process_times(user_mode(get_irq_regs()));
-#endif
+       evt->event_handler(evt);
 
        return IRQ_HANDLED;
 }
@@ -564,17 +622,13 @@ static void __init realview_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, &realview_timer_irq);
 
        realview_clocksource_init();
+       realview_clockevents_init();
 }
 
 struct sys_timer realview_timer = {