0583fe478a
This converts arm and arm64 to use CLKSRC_OF DT based initialization for the arch timer. A new function arch_timer_arch_init is added to allow for arch specific setup. This has a side effect of enabling sched_clock on omap5 and exynos5. There should not be any reason not to use the arch timers for sched_clock. Signed-off-by: Rob Herring <rob.herring@calxeda.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: Tony Lindgren <tony@atomide.com> Cc: Simon Horman <horms@verge.net.au> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-samsung-soc@vger.kernel.org Cc: linux-omap@vger.kernel.org Cc: linux-sh@vger.kernel.org Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
59 lines
1.5 KiB
C
59 lines
1.5 KiB
C
/*
|
|
* linux/arch/arm/kernel/arch_timer.c
|
|
*
|
|
* Copyright (C) 2011 ARM Ltd.
|
|
* All Rights Reserved
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
#include <linux/init.h>
|
|
#include <linux/types.h>
|
|
#include <linux/errno.h>
|
|
|
|
#include <asm/delay.h>
|
|
#include <asm/sched_clock.h>
|
|
|
|
#include <clocksource/arm_arch_timer.h>
|
|
|
|
static unsigned long arch_timer_read_counter_long(void)
|
|
{
|
|
return arch_timer_read_counter();
|
|
}
|
|
|
|
static u32 sched_clock_mult __read_mostly;
|
|
|
|
static unsigned long long notrace arch_timer_sched_clock(void)
|
|
{
|
|
return arch_timer_read_counter() * sched_clock_mult;
|
|
}
|
|
|
|
static struct delay_timer arch_delay_timer;
|
|
|
|
static void __init arch_timer_delay_timer_register(void)
|
|
{
|
|
/* Use the architected timer for the delay loop. */
|
|
arch_delay_timer.read_current_timer = arch_timer_read_counter_long;
|
|
arch_delay_timer.freq = arch_timer_get_rate();
|
|
register_current_timer_delay(&arch_delay_timer);
|
|
}
|
|
|
|
int __init arch_timer_arch_init(void)
|
|
{
|
|
u32 arch_timer_rate = arch_timer_get_rate();
|
|
|
|
if (arch_timer_rate == 0)
|
|
return -ENXIO;
|
|
|
|
arch_timer_delay_timer_register();
|
|
|
|
/* Cache the sched_clock multiplier to save a divide in the hot path. */
|
|
sched_clock_mult = NSEC_PER_SEC / arch_timer_rate;
|
|
sched_clock_func = arch_timer_sched_clock;
|
|
pr_info("sched_clock: ARM arch timer >56 bits at %ukHz, resolution %uns\n",
|
|
arch_timer_rate / 1000, sched_clock_mult);
|
|
|
|
return 0;
|
|
}
|