diff options
Diffstat (limited to 'arch/arm/plat-nomadik/timer.c')
| -rw-r--r-- | arch/arm/plat-nomadik/timer.c | 35 |
1 files changed, 24 insertions, 11 deletions
diff --git a/arch/arm/plat-nomadik/timer.c b/arch/arm/plat-nomadik/timer.c index aedf9c1d645..41723402006 100644 --- a/arch/arm/plat-nomadik/timer.c +++ b/arch/arm/plat-nomadik/timer.c @@ -3,6 +3,7 @@ * * Copyright (C) 2008 STMicroelectronics * Copyright (C) 2010 Alessandro Rubini + * Copyright (C) 2010 Linus Walleij for ST-Ericsson * * 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 @@ -16,11 +17,13 @@ #include <linux/clk.h> #include <linux/jiffies.h> #include <linux/err.h> +#include <linux/sched.h> #include <asm/mach/time.h> +#include <asm/sched_clock.h> #include <plat/mtu.h> -void __iomem *mtu_base; /* ssigned by machine code */ +void __iomem *mtu_base; /* Assigned by machine code */ /* * Kernel assumes that sched_clock can be called early @@ -48,16 +51,25 @@ 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. We accept that - * this wraps around for now, since it is just a relative time - * stamp. (Inspired by OMAP implementation.) + * better resolution when scheduling the kernel. */ +static DEFINE_CLOCK_DATA(cd); + unsigned long long notrace sched_clock(void) { - return clocksource_cyc2ns(nmdk_clksrc.read( - &nmdk_clksrc), - nmdk_clksrc.mult, - nmdk_clksrc.shift); + u32 cyc; + + if (unlikely(!mtu_base)) + return 0; + + cyc = -readl(mtu_base + MTU_VAL(0)); + return cyc_to_sched_clock(&cd, cyc, (u32)~0); +} + +static void notrace nomadik_update_sched_clock(void) +{ + u32 cyc = -readl(mtu_base + MTU_VAL(0)); + update_sched_clock(&cd, cyc, (u32)~0); } /* Clockevent device: use one-shot mode */ @@ -153,7 +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)); @@ -161,13 +172,15 @@ void __init nmdk_timer_init(void) writel(0, mtu_base + MTU_BGLR(0)); writel(cr | MTU_CRn_ENA, mtu_base + MTU_CR(0)); - /* Now the scheduling clock is ready */ + /* 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); + init_sched_clock(&cd, nomadik_update_sched_clock, 32, rate); + /* Timer 1 is used for events */ clockevents_calc_mult_shift(&nmdk_clkevt, rate, MTU_MIN_RANGE); |