diff options
Diffstat (limited to 'arch/arm/kernel/smp_twd.c')
| -rw-r--r-- | arch/arm/kernel/smp_twd.c | 48 |
1 files changed, 46 insertions, 2 deletions
diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c index fef42b21cec..e1f906989bb 100644 --- a/arch/arm/kernel/smp_twd.c +++ b/arch/arm/kernel/smp_twd.c @@ -11,7 +11,6 @@ #include <linux/init.h> #include <linux/kernel.h> #include <linux/clk.h> -#include <linux/cpufreq.h> #include <linux/delay.h> #include <linux/device.h> #include <linux/err.h> @@ -96,7 +95,52 @@ static void twd_timer_stop(struct clock_event_device *clk) disable_percpu_irq(clk->irq); } -#ifdef CONFIG_CPU_FREQ +#ifdef CONFIG_COMMON_CLK + +/* + * Updates clockevent frequency when the cpu frequency changes. + * Called on the cpu that is changing frequency with interrupts disabled. + */ +static void twd_update_frequency(void *new_rate) +{ + twd_timer_rate = *((unsigned long *) new_rate); + + clockevents_update_freq(*__this_cpu_ptr(twd_evt), twd_timer_rate); +} + +static int twd_rate_change(struct notifier_block *nb, + unsigned long flags, void *data) +{ + struct clk_notifier_data *cnd = data; + + /* + * The twd clock events must be reprogrammed to account for the new + * frequency. The timer is local to a cpu, so cross-call to the + * changing cpu. + */ + if (flags == POST_RATE_CHANGE) + smp_call_function(twd_update_frequency, + (void *)&cnd->new_rate, 1); + + return NOTIFY_OK; +} + +static struct notifier_block twd_clk_nb = { + .notifier_call = twd_rate_change, +}; + +static int twd_clk_init(void) +{ + if (twd_evt && *__this_cpu_ptr(twd_evt) && !IS_ERR(twd_clk)) + return clk_notifier_register(twd_clk, &twd_clk_nb); + + return 0; +} +core_initcall(twd_clk_init); + +#elif defined (CONFIG_CPU_FREQ) + +#include <linux/cpufreq.h> /* * Updates clockevent frequency when the cpu frequency changes. |