[MIPS] Clockevent driver for BCM1480

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/sibyte/bcm1480/time.c

@@ -25,6 +25,7 @@
  * code to do general bookkeeping (e.g. update jiffies, run
  * bottom halves, etc.)
  */
+#include <linux/clockchips.h>
 #include <linux/interrupt.h>
 #include <linux/sched.h>
 #include <linux/spinlock.h>
@@ -55,15 +56,12 @@
 
 extern int bcm1480_steal_irq(int irq);
 
-void bcm1480_time_init(void)
+void __init plat_time_init(void)
 {
-	int cpu = smp_processor_id();
-	int irq = K_BCM1480_INT_TIMER_0+cpu;
+	unsigned int cpu = smp_processor_id();
+	unsigned int irq = K_BCM1480_INT_TIMER_0 + cpu;
 
-	/* Only have 4 general purpose timers */
-	if (cpu > 3) {
-		BUG();
-	}
+	BUG_ON(cpu > 3);	/* Only have 4 general purpose timers */
 
 	bcm1480_mask_irq(cpu, irq);
 
@@ -71,27 +69,83 @@ void bcm1480_time_init(void)
 	__raw_writeq(IMR_IP4_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H)
 	      + (irq<<3)));
 
-	/* the general purpose timer ticks at 1 Mhz independent of the rest of the system */
-	/* Disable the timer and set up the count */
-	__raw_writeq(0, IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
-	__raw_writeq(
-		BCM1480_HPT_VALUE/HZ
-		, IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT)));
+	bcm1480_unmask_irq(cpu, irq);
+	bcm1480_steal_irq(irq);
+}
 
-	/* Set the timer running */
+/*
+ * The general purpose timer ticks at 1 Mhz independent if
+ * the rest of the system
+ */
+static void sibyte_set_mode(enum clock_event_mode mode,
+                           struct clock_event_device *evt)
+{
+	unsigned int cpu = smp_processor_id();
+	void __iomem *timer_cfg, *timer_init;
+
+	timer_cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
+	timer_init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
+
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		__raw_writeq(0, timer_cfg);
+		__raw_writeq(BCM1480_HPT_VALUE / HZ - 1, timer_init);
+		__raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS,
+			     timer_cfg);
+		break;
+
+	case CLOCK_EVT_MODE_ONESHOT:
+		/* Stop the timer until we actually program a shot */
+	case CLOCK_EVT_MODE_SHUTDOWN:
+		__raw_writeq(0, timer_cfg);
+		break;
+
+	case CLOCK_EVT_MODE_UNUSED:	/* shuddup gcc */
+		;
+	}
+}
+
+struct clock_event_device sibyte_hpt_clockevent = {
+	.name		= "bcm1480-counter",
+	.features	= CLOCK_EVT_FEAT_PERIODIC,
+	.set_mode	= sibyte_set_mode,
+	.shift		= 32,
+	.irq		= 0,
+};
+
+static irqreturn_t sibyte_counter_handler(int irq, void *dev_id)
+{
+	struct clock_event_device *cd = &sibyte_hpt_clockevent;
+	unsigned int cpu = smp_processor_id();
+
+	/* Reset the timer */
 	__raw_writeq(M_SCD_TIMER_ENABLE|M_SCD_TIMER_MODE_CONTINUOUS,
-	      IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
+	             IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
+	cd->event_handler(cd);
 
-	bcm1480_unmask_irq(cpu, irq);
-	bcm1480_steal_irq(irq);
-	/*
-	 * This interrupt is "special" in that it doesn't use the request_irq
-	 * way to hook the irq line.  The timer interrupt is initialized early
-	 * enough to make this a major pain, and it's also firing enough to
-	 * warrant a bit of special case code.  bcm1480_timer_interrupt is
-	 * called directly from irq_handler.S when IP[4] is set during an
-	 * interrupt
-	 */
+	return IRQ_HANDLED;
+}
+
+static struct irqaction sibyte_counter_irqaction = {
+	.handler	= sibyte_counter_handler,
+	.flags		= IRQF_DISABLED | IRQF_PERCPU,
+	.name		= "timer",
+};
+
+/*
+ * This interrupt is "special" in that it doesn't use the request_irq
+ * way to hook the irq line.  The timer interrupt is initialized early
+ * enough to make this a major pain, and it's also firing enough to
+ * warrant a bit of special case code.  bcm1480_timer_interrupt is
+ * called directly from irq_handler.S when IP[4] is set during an
+ * interrupt
+ */
+static void __init sb1480_clockevent_init(void)
+{
+	unsigned int cpu = smp_processor_id();
+	unsigned int irq = K_BCM1480_INT_TIMER_0 + cpu;
+
+	setup_irq(irq, &sibyte_counter_irqaction);
 }
 
 void bcm1480_timer_interrupt(void)
@@ -118,4 +172,5 @@ void __init bcm1480_hpt_setup(void)
 {
 	clocksource_mips.read = bcm1480_hpt_read;
 	mips_hpt_frequency = BCM1480_HPT_VALUE;
+	sb1480_clockevent_init();
 }