Commit e3f4c0ab authored by Russell King's avatar Russell King
Browse files

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: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 5094b92f

arch/arm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -570,6 +570,7 @@ config ARCH_TEGRA 
	select GENERIC_CLOCKEVENTS

	select GENERIC_GPIO

	select HAVE_CLK

	select HAVE_SCHED_CLOCK

	select COMMON_CLKDEV

	select ARCH_HAS_BARRIERS if CACHE_L2X0

	select ARCH_HAS_CPUFREQ

arch/arm/mach-tegra/timer.c

+21 −2
Original line number Diff line number Diff line
@@ -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();