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author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-06 16:50:35 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-06 16:50:35 -0800 |
commit | 3c0cb7c31c206aaedb967e44b98442bbeb17a6c4 (patch) | |
tree | 3ecba45d7ffae4fba4a5aafaef4af5b0b1105bde /arch/arm/plat-nomadik/timer.c | |
parent | f70f5b9dc74ca7d0a64c4ead3fb28da09dc1b234 (diff) | |
parent | 404a02cbd2ae8bf256a2fa1169bdfe86bb5ebb34 (diff) | |
download | linux-3c0cb7c31c206aaedb967e44b98442bbeb17a6c4.tar.gz linux-3c0cb7c31c206aaedb967e44b98442bbeb17a6c4.tar.bz2 linux-3c0cb7c31c206aaedb967e44b98442bbeb17a6c4.zip |
Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (416 commits)
ARM: DMA: add support for DMA debugging
ARM: PL011: add DMA burst threshold support for ST variants
ARM: PL011: Add support for transmit DMA
ARM: PL011: Ensure IRQs are disabled in UART interrupt handler
ARM: PL011: Separate hardware FIFO size from TTY FIFO size
ARM: PL011: Allow better handling of vendor data
ARM: PL011: Ensure error flags are clear at startup
ARM: PL011: include revision number in boot-time port printk
ARM: vexpress: add sched_clock() for Versatile Express
ARM i.MX53: Make MX53 EVK bootable
ARM i.MX53: Some bug fix about MX53 MSL code
ARM: 6607/1: sa1100: Update platform device registration
ARM: 6606/1: sa1100: Fix platform device registration
ARM i.MX51: rename IPU irqs
ARM i.MX51: Add ipu clock support
ARM: imx/mx27_3ds: Add PMIC support
ARM: DMA: Replace page_to_dma()/dma_to_page() with pfn_to_dma()/dma_to_pfn()
mx51: fix usb clock support
MX51: Add support for usb host 2
arch/arm/plat-mxc/ehci.c: fix errors/typos
...
Diffstat (limited to 'arch/arm/plat-nomadik/timer.c')
-rw-r--r-- | arch/arm/plat-nomadik/timer.c | 80 |
1 files changed, 11 insertions, 69 deletions
diff --git a/arch/arm/plat-nomadik/timer.c b/arch/arm/plat-nomadik/timer.c index 63cdc6025bd7..41723402006b 100644 --- a/arch/arm/plat-nomadik/timer.c +++ b/arch/arm/plat-nomadik/timer.c @@ -17,9 +17,9 @@ #include <linux/clk.h> #include <linux/jiffies.h> #include <linux/err.h> -#include <linux/cnt32_to_63.h> -#include <linux/timer.h> +#include <linux/sched.h> #include <asm/mach/time.h> +#include <asm/sched_clock.h> #include <plat/mtu.h> @@ -52,81 +52,24 @@ static struct clocksource nmdk_clksrc = { * Override the global weak sched_clock symbol with this * local implementation which uses the clocksource to get some * better resolution when scheduling the kernel. - * - * Because the hardware timer period may be quite short - * (32.3 secs on the 133 MHz MTU timer selection on ux500) - * and because cnt32_to_63() needs to be called at least once per - * half period to work properly, a kernel keepwarm() timer is set up - * to ensure this requirement is always met. - * - * Also the sched_clock timer will wrap around at some point, - * here we set it to run continously for a year. */ -#define SCHED_CLOCK_MIN_WRAP 3600*24*365 -static struct timer_list cnt32_to_63_keepwarm_timer; -static u32 sched_mult; -static u32 sched_shift; +static DEFINE_CLOCK_DATA(cd); unsigned long long notrace sched_clock(void) { - u64 cycles; + u32 cyc; if (unlikely(!mtu_base)) return 0; - cycles = cnt32_to_63(-readl(mtu_base + MTU_VAL(0))); - /* - * sched_mult is guaranteed to be even so will - * shift out bit 63 - */ - return (cycles * sched_mult) >> sched_shift; + cyc = -readl(mtu_base + MTU_VAL(0)); + return cyc_to_sched_clock(&cd, cyc, (u32)~0); } -/* Just kick sched_clock every so often */ -static void cnt32_to_63_keepwarm(unsigned long data) +static void notrace nomadik_update_sched_clock(void) { - mod_timer(&cnt32_to_63_keepwarm_timer, round_jiffies(jiffies + data)); - (void) sched_clock(); -} - -/* - * Set up a timer to keep sched_clock():s 32_to_63 algorithm warm - * once in half a 32bit timer wrap interval. - */ -static void __init nmdk_sched_clock_init(unsigned long rate) -{ - u32 v; - unsigned long delta; - u64 days; - - /* Find the apropriate mult and shift factors */ - clocks_calc_mult_shift(&sched_mult, &sched_shift, - rate, NSEC_PER_SEC, SCHED_CLOCK_MIN_WRAP); - /* We need to multiply by an even number to get rid of bit 63 */ - if (sched_mult & 1) - sched_mult++; - - /* Let's see what we get, take max counter and scale it */ - days = (0xFFFFFFFFFFFFFFFFLLU * sched_mult) >> sched_shift; - do_div(days, NSEC_PER_SEC); - do_div(days, (3600*24)); - - pr_info("sched_clock: using %d bits @ %lu Hz wrap in %lu days\n", - (64 - sched_shift), rate, (unsigned long) days); - - /* - * Program a timer to kick us at half 32bit wraparound - * Formula: seconds per wrap = (2^32) / f - */ - v = 0xFFFFFFFFUL / rate; - /* We want half of the wrap time to keep cnt32_to_63 warm */ - v /= 2; - pr_debug("sched_clock: prescaled timer rate: %lu Hz, " - "initialize keepwarm timer every %d seconds\n", rate, v); - /* Convert seconds to jiffies */ - delta = msecs_to_jiffies(v*1000); - setup_timer(&cnt32_to_63_keepwarm_timer, cnt32_to_63_keepwarm, delta); - mod_timer(&cnt32_to_63_keepwarm_timer, round_jiffies(jiffies + delta)); + u32 cyc = -readl(mtu_base + MTU_VAL(0)); + update_sched_clock(&cd, cyc, (u32)~0); } /* Clockevent device: use one-shot mode */ @@ -222,7 +165,6 @@ void __init nmdk_timer_init(void) } else { cr |= MTU_CRn_PRESCALE_1; } - clocksource_calc_mult_shift(&nmdk_clksrc, rate, MTU_MIN_RANGE); /* Timer 0 is the free running clocksource */ writel(cr, mtu_base + MTU_CR(0)); @@ -233,11 +175,11 @@ void __init nmdk_timer_init(void) /* Now the clock source is ready */ nmdk_clksrc.read = nmdk_read_timer; - if (clocksource_register(&nmdk_clksrc)) + if (clocksource_register_hz(&nmdk_clksrc, rate)) pr_err("timer: failed to initialize clock source %s\n", nmdk_clksrc.name); - nmdk_sched_clock_init(rate); + init_sched_clock(&cd, nomadik_update_sched_clock, 32, rate); /* Timer 1 is used for events */ |