ARM: Integrator: convert to generic clockevent support

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 73 insertions, 34 deletions

diff --git a/arch/arm/mach-integrator/core.c b/arch/arm/mach-integrator/core.c
index 87c6f980944d..b1ccbe3f233f 100644
--- a/arch/arm/mach-integrator/core.c
+++ b/arch/arm/mach-integrator/core.c
@@ -20,6 +20,7 @@
 #include <linux/amba/bus.h>
 #include <linux/amba/serial.h>
 #include <linux/clocksource.h>
+#include <linux/clockchips.h>
 #include <linux/io.h>
 
 #include <asm/clkdev.h>
@@ -275,61 +276,99 @@ static void integrator_clocksource_init(u32 khz)
         clocksource_register(cs);
 }
 
+static void __iomem * const clkevt_base = (void __iomem *)TIMER1_VA_BASE;
+
 /*
  * IRQ handler for the timer
  */
-static irqreturn_t
-integrator_timer_interrupt(int irq, void *dev_id)
+static irqreturn_t integrator_timer_interrupt(int irq, void *dev_id)
 {
-        /*
-         * clear the interrupt
-         */
-        writel(1, TIMER1_VA_BASE + TIMER_INTCLR);
+        struct clock_event_device *evt = dev_id;
+
+        /* clear the interrupt */
+        writel(1, clkevt_base + TIMER_INTCLR);
 
-        timer_tick();
+        evt->event_handler(evt);
 
         return IRQ_HANDLED;
 }
 
+static void clkevt_set_mode(enum clock_event_mode mode, struct clock_event_device *evt)
+{
+        u32 ctrl = readl(clkevt_base + TIMER_CTRL) & ~TIMER_CTRL_ENABLE;
+
+        BUG_ON(mode == CLOCK_EVT_MODE_ONESHOT);
+
+        if (mode == CLOCK_EVT_MODE_PERIODIC) {
+                writel(ctrl, clkevt_base + TIMER_CTRL);
+                writel(timer_reload, clkevt_base + TIMER_LOAD);
+                ctrl |= TIMER_CTRL_PERIODIC | TIMER_CTRL_ENABLE;
+        }
+
+        writel(ctrl, clkevt_base + TIMER_CTRL);
+}
+
+static int clkevt_set_next_event(unsigned long next, struct clock_event_device *evt)
+{
+        unsigned long ctrl = readl(clkevt_base + TIMER_CTRL);
+
+        writel(ctrl & ~TIMER_CTRL_ENABLE, clkevt_base + TIMER_CTRL);
+        writel(next, clkevt_base + TIMER_LOAD);
+        writel(ctrl | TIMER_CTRL_ENABLE, clkevt_base + TIMER_CTRL);
+
+        return 0;
+}
+
+static struct clock_event_device integrator_clockevent = {
+        .name           = "timer1",
+        .shift          = 34,
+        .features       = CLOCK_EVT_FEAT_PERIODIC,
+        .set_mode       = clkevt_set_mode,
+        .set_next_event = clkevt_set_next_event,
+        .rating         = 300,
+        .cpumask        = cpu_all_mask,
+};
+
 static struct irqaction integrator_timer_irq = {
-        .name           = "Integrator Timer Tick",
+        .name           = "timer",
         .flags          = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
         .handler        = integrator_timer_interrupt,
+        .dev_id         = &integrator_clockevent,
 };
 
-/*
- * Set up timer interrupt, and return the current time in seconds.
- */
-void __init integrator_time_init(unsigned long reload, unsigned int ctrl)
+static void integrator_clockevent_init(u32 khz, unsigned int ctrl)
 {
-        unsigned int timer_ctrl = TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC;
+        struct clock_event_device *evt = &integrator_clockevent;
 
-        integrator_clocksource_init(reload * HZ / 1000);
+        if (khz * 1000 > 0x100000 * HZ) {
+                khz /= 256;
+                ctrl |= TIMER_CTRL_DIV256;
+        } else if (khz * 1000 > 0x10000 * HZ) {
+                khz /= 16;
+                ctrl |= TIMER_CTRL_DIV16;
+        }
 
-        timer_reload = reload;
-        timer_ctrl |= ctrl;
+        timer_reload = khz * 1000 / HZ;
+        writel(ctrl, clkevt_base + TIMER_CTRL);
 
-        if (timer_reload > 0x100000) {
-                timer_reload >>= 8;
-                timer_ctrl |= TIMER_CTRL_DIV256;
-        } else if (timer_reload > 0x010000) {
-                timer_reload >>= 4;
-                timer_ctrl |= TIMER_CTRL_DIV16;
-        }
+        evt->irq = IRQ_TIMERINT1;
+        evt->mult = div_sc(khz, NSEC_PER_MSEC, evt->shift);
+        evt->max_delta_ns = clockevent_delta2ns(0xffff, evt);
+        evt->min_delta_ns = clockevent_delta2ns(0xf, evt);
 
-        /*
-         * Initialise to a known state (all timers off)
-         */
+        setup_irq(IRQ_TIMERINT1, &integrator_timer_irq);
+        clockevents_register_device(evt);
+}
+
+/*
+ * Set up timer(s).
+ */
+void __init integrator_time_init(unsigned long reload, unsigned int ctrl)
+{
         writel(0, TIMER0_VA_BASE + TIMER_CTRL);
         writel(0, TIMER1_VA_BASE + TIMER_CTRL);
         writel(0, TIMER2_VA_BASE + TIMER_CTRL);
 
-        writel(timer_reload, TIMER1_VA_BASE + TIMER_LOAD);
-        writel(timer_reload, TIMER1_VA_BASE + TIMER_VALUE);
-        writel(timer_ctrl, TIMER1_VA_BASE + TIMER_CTRL);
-
-        /*
-         * Make irqs happen for the system timer
-         */
-        setup_irq(IRQ_TIMERINT1, &integrator_timer_irq);
+        integrator_clocksource_init(reload * HZ / 1000);
+        integrator_clockevent_init(reload * HZ / 1000, ctrl);
 }