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author | Linus Torvalds <torvalds@woody.osdl.org> | 2006-12-07 15:40:39 -0800 |
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committer | Linus Torvalds <torvalds@woody.osdl.org> | 2006-12-07 15:40:39 -0800 |
commit | ea14fad0d416354a4e9bb1a04f32acba706f9548 (patch) | |
tree | 2c8acc5331f189aef1d40ddce3f40d6be9314e77 /arch/arm/mach-imx/time.c | |
parent | 6ee7e78e7c78d871409ad4df30551c9355be7d0e (diff) | |
parent | 6705cda24fad1cb0ac82ac4f312df8ec735b39b0 (diff) | |
download | blackbird-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.c | 86 |
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, }; |