diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-12-15 21:49:42 +0000 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-12-22 22:44:47 +0000 |
| commit | e3f4c0ab916334e861fc49eeb2673a8c13e978e7 (patch) | |
| tree | b3275eb4e32b4d4037dc67ad380dfcdacc20750c /arch/arm/mach-tegra/timer.c | |
| parent | 5094b92f1c7d0f21c5d4411ba7415bac0684210f (diff) | |
ARM: tegra: convert sched_clock() to use new infrastructure
Convert tegra to use the new sched_clock() infrastructure for extending
32bit counters to full 64-bit nanoseconds.
Tested-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-tegra/timer.c')
| -rw-r--r-- | arch/arm/mach-tegra/timer.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/arch/arm/mach-tegra/timer.c b/arch/arm/mach-tegra/timer.c index c52bd84652e5..7b8ad1f98f44 100644 --- a/arch/arm/mach-tegra/timer.c +++ b/arch/arm/mach-tegra/timer.c @@ -26,10 +26,10 @@ #include <linux/clocksource.h> #include <linux/clk.h> #include <linux/io.h> -#include <linux/cnt32_to_63.h> #include <asm/mach/time.h> #include <asm/localtimer.h> +#include <asm/sched_clock.h> #include <mach/iomap.h> #include <mach/irqs.h> @@ -111,9 +111,25 @@ static struct clocksource tegra_clocksource = { .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; +static DEFINE_CLOCK_DATA(cd); + +/* + * Constants generated by clocks_calc_mult_shift(m, s, 1MHz, NSEC_PER_SEC, 60). + * This gives a resolution of about 1us and a wrap period of about 1h11min. + */ +#define SC_MULT 4194304000u +#define SC_SHIFT 22 + unsigned long long notrace sched_clock(void) { - return cnt32_to_63(timer_readl(TIMERUS_CNTR_1US)) * 1000; + u32 cyc = timer_readl(TIMERUS_CNTR_1US); + return cyc_to_fixed_sched_clock(&cd, cyc, (u32)~0, SC_MULT, SC_SHIFT); +} + +static void notrace tegra_update_sched_clock(void) +{ + u32 cyc = timer_readl(TIMERUS_CNTR_1US); + update_sched_clock(&cd, cyc, (u32)~0); } static irqreturn_t tegra_timer_interrupt(int irq, void *dev_id) @@ -158,6 +174,9 @@ static void __init tegra_init_timer(void) WARN(1, "Unknown clock rate"); } + init_fixed_sched_clock(&cd, tegra_update_sched_clock, 32, + 1000000, SC_MULT, SC_SHIFT); + if (clocksource_register_hz(&tegra_clocksource, 1000000)) { printk(KERN_ERR "Failed to register clocksource\n"); BUG(); |