diff options
Diffstat (limited to 'arch/i386/kernel/hpet.c')
| -rw-r--r-- | arch/i386/kernel/hpet.c | 98 |
1 files changed, 30 insertions, 68 deletions
diff --git a/arch/i386/kernel/hpet.c b/arch/i386/kernel/hpet.c index 17d73459fc5f..533d4932bc79 100644 --- a/arch/i386/kernel/hpet.c +++ b/arch/i386/kernel/hpet.c @@ -5,6 +5,7 @@ #include <linux/init.h> #include <linux/sysdev.h> #include <linux/pm.h> +#include <linux/delay.h> #include <asm/hpet.h> #include <asm/io.h> @@ -187,6 +188,10 @@ static void hpet_set_mode(enum clock_event_mode mode, cfg &= ~HPET_TN_ENABLE; hpet_writel(cfg, HPET_T0_CFG); break; + + case CLOCK_EVT_MODE_RESUME: + hpet_enable_int(); + break; } } @@ -217,6 +222,7 @@ static struct clocksource clocksource_hpet = { .mask = HPET_MASK, .shift = HPET_SHIFT, .flags = CLOCK_SOURCE_IS_CONTINUOUS, + .resume = hpet_start_counter, }; /* @@ -226,7 +232,8 @@ int __init hpet_enable(void) { unsigned long id; uint64_t hpet_freq; - u64 tmp; + u64 tmp, start, now; + cycle_t t1; if (!is_hpet_capable()) return 0; @@ -273,6 +280,27 @@ int __init hpet_enable(void) /* Start the counter */ hpet_start_counter(); + /* Verify whether hpet counter works */ + t1 = read_hpet(); + rdtscll(start); + + /* + * We don't know the TSC frequency yet, but waiting for + * 200000 TSC cycles is safe: + * 4 GHz == 50us + * 1 GHz == 200us + */ + do { + rep_nop(); + rdtscll(now); + } while ((now - start) < 200000UL); + + if (t1 == read_hpet()) { + printk(KERN_WARNING + "HPET counter not counting. HPET disabled\n"); + goto out_nohpet; + } + /* Initialize and register HPET clocksource * * hpet period is in femto seconds per cycle @@ -291,7 +319,6 @@ int __init hpet_enable(void) clocksource_register(&clocksource_hpet); - if (id & HPET_ID_LEGSUP) { hpet_enable_int(); hpet_reserve_platform_timers(id); @@ -299,7 +326,7 @@ int __init hpet_enable(void) * Start hpet with the boot cpu mask and make it * global after the IO_APIC has been initialized. */ - hpet_clockevent.cpumask =cpumask_of_cpu(0); + hpet_clockevent.cpumask = cpumask_of_cpu(smp_processor_id()); clockevents_register_device(&hpet_clockevent); global_clock_event = &hpet_clockevent; return 1; @@ -524,68 +551,3 @@ irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id) return IRQ_HANDLED; } #endif - - -/* - * Suspend/resume part - */ - -#ifdef CONFIG_PM - -static int hpet_suspend(struct sys_device *sys_device, pm_message_t state) -{ - unsigned long cfg = hpet_readl(HPET_CFG); - - cfg &= ~(HPET_CFG_ENABLE|HPET_CFG_LEGACY); - hpet_writel(cfg, HPET_CFG); - - return 0; -} - -static int hpet_resume(struct sys_device *sys_device) -{ - unsigned int id; - - hpet_start_counter(); - - id = hpet_readl(HPET_ID); - - if (id & HPET_ID_LEGSUP) - hpet_enable_int(); - - return 0; -} - -static struct sysdev_class hpet_class = { - set_kset_name("hpet"), - .suspend = hpet_suspend, - .resume = hpet_resume, -}; - -static struct sys_device hpet_device = { - .id = 0, - .cls = &hpet_class, -}; - - -static __init int hpet_register_sysfs(void) -{ - int err; - - if (!is_hpet_capable()) - return 0; - - err = sysdev_class_register(&hpet_class); - - if (!err) { - err = sysdev_register(&hpet_device); - if (err) - sysdev_class_unregister(&hpet_class); - } - - return err; -} - -device_initcall(hpet_register_sysfs); - -#endif |