[ARM] 4259/1: clockevent support for ixp4xx platform
Update ixp4xx timer support to use new clockevent infrastructure.
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 2d13b01..2aadd0e 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -266,6 +266,7 @@
bool "IXP4xx-based"
depends on MMU
select GENERIC_TIME
+ select GENERIC_CLOCKEVENTS
help
Support for Intel's IXP4XX (XScale) family of processors.
diff --git a/arch/arm/mach-ixp4xx/common.c b/arch/arm/mach-ixp4xx/common.c
index 45068c3..09edea9 100644
--- a/arch/arm/mach-ixp4xx/common.c
+++ b/arch/arm/mach-ixp4xx/common.c
@@ -27,6 +27,7 @@
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/clocksource.h>
+#include <linux/clockchips.h>
#include <asm/arch/udc.h>
#include <asm/hardware.h>
@@ -41,6 +42,8 @@
#include <asm/mach/time.h>
static int __init ixp4xx_clocksource_init(void);
+static int __init ixp4xx_clockevent_init(void);
+static struct clock_event_device clockevent_ixp4xx;
/*************************************************************************
* IXP4xx chipset I/O mapping
@@ -239,52 +242,40 @@
* counter as a source of real clock ticks to account for missed jiffies.
*************************************************************************/
-static unsigned volatile last_jiffy_time;
-
-#define CLOCK_TICKS_PER_USEC ((CLOCK_TICK_RATE + USEC_PER_SEC/2) / USEC_PER_SEC)
-
static irqreturn_t ixp4xx_timer_interrupt(int irq, void *dev_id)
{
- write_seqlock(&xtime_lock);
+ struct clock_event_device *evt = &clockevent_ixp4xx;
/* Clear Pending Interrupt by writing '1' to it */
*IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND;
- /*
- * Catch up with the real idea of time
- */
- while ((signed long)(*IXP4XX_OSTS - last_jiffy_time) >= LATCH) {
- timer_tick();
- last_jiffy_time += LATCH;
- }
-
- write_sequnlock(&xtime_lock);
+ evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction ixp4xx_timer_irq = {
- .name = "IXP4xx Timer Tick",
+ .name = "timer1",
.flags = IRQF_DISABLED | IRQF_TIMER,
.handler = ixp4xx_timer_interrupt,
};
static void __init ixp4xx_timer_init(void)
{
+ /* Reset/disable counter */
+ *IXP4XX_OSRT1 = 0;
+
/* Clear Pending Interrupt by writing '1' to it */
*IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND;
- /* Setup the Timer counter value */
- *IXP4XX_OSRT1 = (LATCH & ~IXP4XX_OST_RELOAD_MASK) | IXP4XX_OST_ENABLE;
-
/* Reset time-stamp counter */
*IXP4XX_OSTS = 0;
- last_jiffy_time = 0;
/* Connect the interrupt handler and enable the interrupt */
setup_irq(IRQ_IXP4XX_TIMER1, &ixp4xx_timer_irq);
ixp4xx_clocksource_init();
+ ixp4xx_clockevent_init();
}
struct sys_timer ixp4xx_timer = {
@@ -384,6 +375,9 @@
ixp4xx_exp_bus_size >> 20);
}
+/*
+ * clocksource
+ */
cycle_t ixp4xx_get_cycles(void)
{
return *IXP4XX_OSTS;
@@ -408,3 +402,64 @@
return 0;
}
+
+/*
+ * clockevents
+ */
+static int ixp4xx_set_next_event(unsigned long evt,
+ struct clock_event_device *unused)
+{
+ unsigned long opts = *IXP4XX_OSRT1 & IXP4XX_OST_RELOAD_MASK;
+
+ *IXP4XX_OSRT1 = (evt & ~IXP4XX_OST_RELOAD_MASK) | opts;
+
+ return 0;
+}
+
+static void ixp4xx_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ unsigned long opts, osrt = *IXP4XX_OSRT1 & ~IXP4XX_OST_RELOAD_MASK;
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ osrt = LATCH & ~IXP4XX_OST_RELOAD_MASK;
+ opts = IXP4XX_OST_ENABLE;
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ /* period set by 'set next_event' */
+ osrt = 0;
+ opts = IXP4XX_OST_ENABLE | IXP4XX_OST_ONE_SHOT;
+ break;
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_UNUSED:
+ default:
+ osrt = opts = 0;
+ break;
+ }
+
+ *IXP4XX_OSRT1 = osrt | opts;
+}
+
+static struct clock_event_device clockevent_ixp4xx = {
+ .name = "ixp4xx timer1",
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .rating = 200,
+ .shift = 24,
+ .set_mode = ixp4xx_set_mode,
+ .set_next_event = ixp4xx_set_next_event,
+};
+
+static int __init ixp4xx_clockevent_init(void)
+{
+ clockevent_ixp4xx.mult = div_sc(FREQ, NSEC_PER_SEC,
+ clockevent_ixp4xx.shift);
+ clockevent_ixp4xx.max_delta_ns =
+ clockevent_delta2ns(0xfffffffe, &clockevent_ixp4xx);
+ clockevent_ixp4xx.min_delta_ns =
+ clockevent_delta2ns(0xf, &clockevent_ixp4xx);
+ clockevent_ixp4xx.cpumask = cpumask_of_cpu(0);
+
+ clockevents_register_device(&clockevent_ixp4xx);
+ return 0;
+}