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authorLinus Torvalds <torvalds@woody.osdl.org>2006-12-07 15:40:39 -0800
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-07 15:40:39 -0800
commitea14fad0d416354a4e9bb1a04f32acba706f9548 (patch)
tree2c8acc5331f189aef1d40ddce3f40d6be9314e77 /arch/arm/mach-imx/time.c
parent6ee7e78e7c78d871409ad4df30551c9355be7d0e (diff)
parent6705cda24fad1cb0ac82ac4f312df8ec735b39b0 (diff)
downloadblackbird-op-linux-ea14fad0d416354a4e9bb1a04f32acba706f9548.tar.gz
blackbird-op-linux-ea14fad0d416354a4e9bb1a04f32acba706f9548.zip
Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (76 commits) [ARM] 4002/1: S3C24XX: leave parent IRQs unmasked [ARM] 4001/1: S3C24XX: shorten reboot time [ARM] 3983/2: remove unused argument to __bug() [ARM] 4000/1: Osiris: add third serial port in [ARM] 3999/1: RX3715: suspend to RAM support [ARM] 3998/1: VR1000: LED platform devices [ARM] 3995/1: iop13xx: add iop13xx support [ARM] 3968/1: iop13xx: add iop13xx_defconfig [ARM] Update mach-types [ARM] Allow gcc to optimise arm_add_memory a little more [ARM] 3991/1: i.MX/MX1 high resolution time source [ARM] 3990/1: i.MX/MX1 more precise PLL decode [ARM] 3986/1: H1940: suspend to RAM support [ARM] 3985/1: ixp4xx clocksource cleanup [ARM] 3984/1: ixp4xx/nslu2: Fix disk LED numbering (take 2) [ARM] 3994/1: ixp23xx: fix handling of pci master aborts [ARM] 3981/1: sched_clock for PXA2xx [ARM] 3980/1: extend the ARM Versatile sched_clock implementation from 32 to 63 bit [ARM] 3979/1: extend the SA11x0 sched_clock implementation from 32 to 63 bit period [ARM] 3978/1: macro to provide a 63-bit value from a 32-bit hardware counter ...
Diffstat (limited to 'arch/arm/mach-imx/time.c')
-rw-r--r--arch/arm/mach-imx/time.c86
1 files changed, 50 insertions, 36 deletions
diff --git a/arch/arm/mach-imx/time.c b/arch/arm/mach-imx/time.c
index 8ae4a2c5066f..40039b2a90b3 100644
--- a/arch/arm/mach-imx/time.c
+++ b/arch/arm/mach-imx/time.c
@@ -14,6 +14,7 @@
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/time.h>
+#include <linux/clocksource.h>
#include <asm/hardware.h>
#include <asm/io.h>
@@ -24,33 +25,7 @@
/* Use timer 1 as system timer */
#define TIMER_BASE IMX_TIM1_BASE
-/*
- * Returns number of us since last clock interrupt. Note that interrupts
- * will have been disabled by do_gettimeoffset()
- */
-static unsigned long imx_gettimeoffset(void)
-{
- unsigned long ticks;
-
- /*
- * Get the current number of ticks. Note that there is a race
- * condition between us reading the timer and checking for
- * an interrupt. We get around this by ensuring that the
- * counter has not reloaded between our two reads.
- */
- ticks = IMX_TCN(TIMER_BASE);
-
- /*
- * Interrupt pending? If so, we've reloaded once already.
- */
- if (IMX_TSTAT(TIMER_BASE) & TSTAT_COMP)
- ticks += LATCH;
-
- /*
- * Convert the ticks to usecs
- */
- return (1000000 / CLK32) * ticks;
-}
+static unsigned long evt_diff;
/*
* IRQ handler for the timer
@@ -58,14 +33,23 @@ static unsigned long imx_gettimeoffset(void)
static irqreturn_t
imx_timer_interrupt(int irq, void *dev_id)
{
- write_seqlock(&xtime_lock);
+ uint32_t tstat;
/* clear the interrupt */
- if (IMX_TSTAT(TIMER_BASE))
- IMX_TSTAT(TIMER_BASE) = 0;
+ tstat = IMX_TSTAT(TIMER_BASE);
+ IMX_TSTAT(TIMER_BASE) = 0;
+
+ if (tstat & TSTAT_COMP) {
+ do {
+
+ write_seqlock(&xtime_lock);
+ timer_tick();
+ write_sequnlock(&xtime_lock);
+ IMX_TCMP(TIMER_BASE) += evt_diff;
- timer_tick();
- write_sequnlock(&xtime_lock);
+ } while (unlikely((int32_t)(IMX_TCMP(TIMER_BASE)
+ - IMX_TCN(TIMER_BASE)) < 0));
+ }
return IRQ_HANDLED;
}
@@ -77,9 +61,9 @@ static struct irqaction imx_timer_irq = {
};
/*
- * Set up timer interrupt, and return the current time in seconds.
+ * Set up timer hardware into expected mode and state.
*/
-static void __init imx_timer_init(void)
+static void __init imx_timer_hardware_init(void)
{
/*
* Initialise to a known state (all timers off, and timing reset)
@@ -87,7 +71,38 @@ static void __init imx_timer_init(void)
IMX_TCTL(TIMER_BASE) = 0;
IMX_TPRER(TIMER_BASE) = 0;
IMX_TCMP(TIMER_BASE) = LATCH - 1;
- IMX_TCTL(TIMER_BASE) = TCTL_CLK_32 | TCTL_IRQEN | TCTL_TEN;
+
+ IMX_TCTL(TIMER_BASE) = TCTL_FRR | TCTL_CLK_PCLK1 | TCTL_IRQEN | TCTL_TEN;
+ evt_diff = LATCH;
+}
+
+cycle_t imx_get_cycles(void)
+{
+ return IMX_TCN(TIMER_BASE);
+}
+
+static struct clocksource clocksource_imx = {
+ .name = "imx_timer1",
+ .rating = 200,
+ .read = imx_get_cycles,
+ .mask = 0xFFFFFFFF,
+ .shift = 20,
+ .is_continuous = 1,
+};
+
+static int __init imx_clocksource_init(void)
+{
+ clocksource_imx.mult =
+ clocksource_hz2mult(imx_get_perclk1(), clocksource_imx.shift);
+ clocksource_register(&clocksource_imx);
+
+ return 0;
+}
+
+static void __init imx_timer_init(void)
+{
+ imx_timer_hardware_init();
+ imx_clocksource_init();
/*
* Make irqs happen for the system timer
@@ -97,5 +112,4 @@ static void __init imx_timer_init(void)
struct sys_timer imx_timer = {
.init = imx_timer_init,
- .offset = imx_gettimeoffset,
};
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