Add a clockevent driver for i.MX systems.
Signed-off-by: Luotao Fu <[email protected]>
Signed-off-by: Sascha Hauer <[email protected]>
---
arch/arm/mach-imx/time.c | 71 +++++++++++++++++++++++++++++++++++++++--------
1 file changed, 59 insertions(+), 12 deletions(-)
Index: arch/arm/mach-imx/time.c
===================================================================
--- a/arch/arm/mach-imx/time.c.orig
+++ b/arch/arm/mach-imx/time.c
@@ -15,6 +15,7 @@
#include <linux/irq.h>
#include <linux/time.h>
#include <linux/clocksource.h>
+#include <linux/clockchips.h>
#include <asm/hardware.h>
#include <asm/io.h>
@@ -25,7 +26,52 @@
/* Use timer 1 as system timer */
#define TIMER_BASE IMX_TIM1_BASE
-static unsigned long evt_diff;
+enum clock_event_mode clockevent_mode = 0;
+
+static void imx_set_next_event(unsigned long evt,
+ struct clock_event_device *unused)
+{
+ IMX_TCMP(IMX_TIM1_BASE) = IMX_TCN(IMX_TIM1_BASE) + evt;
+}
+
+static void imx_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ switch (mode) {
+ case CLOCK_EVT_PERIODIC:
+ case CLOCK_EVT_ONESHOT:
+ IMX_TCTL(TIMER_BASE) |= TCTL_IRQEN;
+ break;
+
+ case CLOCK_EVT_SHUTDOWN:
+ IMX_TCTL(TIMER_BASE) &= ~TCTL_IRQEN;
+ return;
+ }
+
+ clockevent_mode = mode;
+}
+
+static struct clock_event_device clockevent_imx = {
+ .name = "imx_timer1",
+ .capabilities = CLOCK_CAP_NEXTEVT | CLOCK_CAP_TICK |
+ CLOCK_CAP_UPDATE | CLOCK_CAP_PROFILE,
+ .shift = 32,
+ .set_mode = imx_set_mode,
+ .set_next_event = imx_set_next_event,
+};
+
+static int __init imx_clockevent_init(void)
+{
+ clockevent_imx.mult = div_sc(imx_get_perclk1(), NSEC_PER_SEC,
+ clockevent_imx.shift);
+ clockevent_imx.max_delta_ns =
+ clockevent_delta2ns(0xfffffffe, &clockevent_imx);
+ clockevent_imx.min_delta_ns =
+ clockevent_delta2ns(0xf, &clockevent_imx);
+ register_local_clockevent(&clockevent_imx);
+
+ return 0;
+}
/*
* IRQ handler for the timer
@@ -42,10 +88,12 @@ imx_timer_interrupt(int irq, void *dev_i
if (tstat & TSTAT_COMP) {
do {
- write_seqlock(&xtime_lock);
- timer_tick();
- write_sequnlock(&xtime_lock);
- IMX_TCMP(TIMER_BASE) += evt_diff;
+ clockevent_imx.event_handler();
+
+ if (clockevent_mode != CLOCK_EVT_PERIODIC)
+ break;
+
+ IMX_TCMP(TIMER_BASE) += LATCH;
} while (unlikely((int32_t)(IMX_TCMP(TIMER_BASE)
- IMX_TCN(TIMER_BASE)) < 0));
@@ -70,10 +118,8 @@ static void __init imx_timer_hardware_in
*/
IMX_TCTL(TIMER_BASE) = 0;
IMX_TPRER(TIMER_BASE) = 0;
- IMX_TCMP(TIMER_BASE) = LATCH - 1;
-
- IMX_TCTL(TIMER_BASE) = TCTL_FRR | TCTL_CLK_PCLK1 | TCTL_IRQEN | TCTL_TEN;
- evt_diff = LATCH;
+ IMX_TCMP(TIMER_BASE) = LATCH;
+ IMX_TCTL(TIMER_BASE) = TCTL_FRR | TCTL_CLK_PCLK1 | TCTL_TEN | TCTL_IRQEN;
}
cycle_t imx_get_cycles(void)
@@ -82,12 +128,12 @@ cycle_t imx_get_cycles(void)
}
static struct clocksource clocksource_imx = {
- .name = "imx_timer1",
+ .name = "imx_timer1",
.rating = 200,
.read = imx_get_cycles,
.mask = 0xFFFFFFFF,
- .shift = 20,
- .is_continuous = 1,
+ .shift = 20,
+ .is_continuous = 1,
};
static int __init imx_clocksource_init(void)
@@ -103,6 +149,7 @@ static void __init imx_timer_init(void)
{
imx_timer_hardware_init();
imx_clocksource_init();
+ imx_clockevent_init();
/*
* Make irqs happen for the system timer
--
Dipl.-Ing. Sascha Hauer | http://www.pengutronix.de
Pengutronix - Linux Solutions for Science and Industry
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Hannoversche Str. 2, 31134 Hildesheim, Germany
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