diff options
| -rw-r--r-- | arch/arm/include/asm/smp_twd.h | 8 | ||||
| -rw-r--r-- | arch/arm/kernel/smp_twd.c | 41 |
2 files changed, 35 insertions, 14 deletions
diff --git a/arch/arm/include/asm/smp_twd.h b/arch/arm/include/asm/smp_twd.h index 79aebe2ad7a8..ce0a8b95da39 100644 --- a/arch/arm/include/asm/smp_twd.h +++ b/arch/arm/include/asm/smp_twd.h @@ -37,12 +37,4 @@ void twd_timer_setup(struct clock_event_device *); void twd_timer_setup_scalable(struct clock_event_device *, unsigned long target_rate, unsigned int periphclk_prescaler); -/* - * Recalculate the twd prescaler value when the cpu frequency changes. To - * prevent early timer interrupts, must be called before changing the cpu - * frequency if the frequency is increasing, or after if the frequency is - * decreasing. - */ -void twd_recalc_prescaler(unsigned long new_rate); - #endif diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c index 97f934967850..3dc62ee45639 100644 --- a/arch/arm/kernel/smp_twd.c +++ b/arch/arm/kernel/smp_twd.c @@ -17,6 +17,7 @@ #include <linux/clockchips.h> #include <linux/irq.h> #include <linux/io.h> +#include <linux/cpufreq.h> #include <asm/smp_twd.h> #include <asm/hardware/gic.h> @@ -88,7 +89,7 @@ int twd_timer_ack(void) * frequency if the frequency is increasing, or after if the frequency is * decreasing. */ -void twd_recalc_prescaler(unsigned long new_rate) +static void twd_update_prescaler(void *data) { u32 ctrl; int prescaler; @@ -96,9 +97,7 @@ void twd_recalc_prescaler(unsigned long new_rate) BUG_ON(twd_periphclk_prescaler == 0 || twd_timer_rate == 0); - twd_cpu_rate = new_rate; - - periphclk_rate = new_rate / twd_periphclk_prescaler; + periphclk_rate = twd_cpu_rate / twd_periphclk_prescaler; prescaler = DIV_ROUND_UP(periphclk_rate, twd_timer_rate); prescaler = clamp(prescaler - 1, 0, 0xFF); @@ -109,6 +108,36 @@ void twd_recalc_prescaler(unsigned long new_rate) __raw_writel(ctrl, twd_base + TWD_TIMER_CONTROL); } +static int twd_cpufreq_transition(struct notifier_block *nb, + unsigned long state, void *data) +{ + struct cpufreq_freqs *freqs = data; + if (((freqs->new > freqs->old) && state == CPUFREQ_PRECHANGE) || + ((freqs->old > freqs->new) && state == CPUFREQ_POSTCHANGE)) { + /* freqs->new is in kHz, twd_cpu_rate is in Hz */ + twd_cpu_rate = freqs->new * 1000; + + smp_call_function_single(freqs->cpu, twd_update_prescaler, + NULL, 1); + } + + return NOTIFY_OK; +} + +static struct notifier_block twd_cpufreq_nb = { + .notifier_call = twd_cpufreq_transition, +}; + +static int twd_cpufreq_init(void) +{ + if (twd_cpu_rate) + return cpufreq_register_notifier(&twd_cpufreq_nb, + CPUFREQ_TRANSITION_NOTIFIER); + + return 0; +} +core_initcall(twd_cpufreq_init); + static void __cpuinit twd_calibrate_rate(unsigned long target_rate, unsigned int periphclk_prescaler) { @@ -156,7 +185,7 @@ static void __cpuinit twd_calibrate_rate(unsigned long target_rate, (twd_timer_rate / 10000) % 100); twd_cpu_rate = twd_timer_rate * periphclk_prescaler; twd_timer_rate = target_rate; - twd_recalc_prescaler(twd_cpu_rate); + twd_update_prescaler(NULL); } printk("%lu.%02luMHz.\n", twd_timer_rate / 1000000, @@ -164,7 +193,7 @@ static void __cpuinit twd_calibrate_rate(unsigned long target_rate, } else { if (target_rate) { BUG_ON(target_rate != twd_timer_rate); - twd_recalc_prescaler(twd_cpu_rate); + twd_update_prescaler(NULL); } } |