diff options
| -rw-r--r-- | arch/mips/kernel/cevt-r4k.c | 12 | ||||
| -rw-r--r-- | arch/mips/kernel/time.c | 87 | ||||
| -rw-r--r-- | include/asm-mips/time.h | 5 |
3 files changed, 43 insertions, 61 deletions
diff --git a/arch/mips/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c index 076f52b9bb79..24a2d907aa0d 100644 --- a/arch/mips/kernel/cevt-r4k.c +++ b/arch/mips/kernel/cevt-r4k.c @@ -219,7 +219,7 @@ static int c0_compare_int_usable(void) return 1; } -void __cpuinit mips_clockevent_init(void) +int __cpuinit mips_clockevent_init(void) { uint64_t mips_freq = mips_hpt_frequency; unsigned int cpu = smp_processor_id(); @@ -227,7 +227,7 @@ void __cpuinit mips_clockevent_init(void) unsigned int irq; if (!cpu_has_counter || !mips_hpt_frequency) - return; + return -ENXIO; #ifdef CONFIG_MIPS_MT_SMTC setup_smtc_dummy_clockevent_device(); @@ -237,11 +237,11 @@ void __cpuinit mips_clockevent_init(void) * device. */ if (cpu) - return; + return 0; #endif if (!c0_compare_int_usable()) - return; + return -ENXIO; /* * With vectored interrupts things are getting platform specific. @@ -277,7 +277,7 @@ void __cpuinit mips_clockevent_init(void) clockevents_register_device(cd); if (cp0_timer_irq_installed) - return; + return 0; cp0_timer_irq_installed = 1; @@ -287,4 +287,6 @@ void __cpuinit mips_clockevent_init(void) #else setup_irq(irq, &c0_compare_irqaction); #endif + + return 0; } diff --git a/arch/mips/kernel/time.c b/arch/mips/kernel/time.c index 3284b9b4ecac..d7d52efff51f 100644 --- a/arch/mips/kernel/time.c +++ b/arch/mips/kernel/time.c @@ -91,48 +91,6 @@ static struct clocksource clocksource_mips = { .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; -static unsigned int __init calibrate_hpt(void) -{ - cycle_t frequency, hpt_start, hpt_end, hpt_count, hz; - - const int loops = HZ / 10; - int log_2_loops = 0; - int i; - - /* - * We want to calibrate for 0.1s, but to avoid a 64-bit - * division we round the number of loops up to the nearest - * power of 2. - */ - while (loops > 1 << log_2_loops) - log_2_loops++; - i = 1 << log_2_loops; - - /* - * Wait for a rising edge of the timer interrupt. - */ - while (mips_timer_state()); - while (!mips_timer_state()); - - /* - * Now see how many high precision timer ticks happen - * during the calculated number of periods between timer - * interrupts. - */ - hpt_start = clocksource_mips.read(); - do { - while (mips_timer_state()); - while (!mips_timer_state()); - } while (--i); - hpt_end = clocksource_mips.read(); - - hpt_count = (hpt_end - hpt_start) & clocksource_mips.mask; - hz = HZ; - frequency = hpt_count * hz; - - return frequency >> log_2_loops; -} - void __init clocksource_set_clock(struct clocksource *cs, unsigned int clock) { u64 temp; @@ -194,21 +152,42 @@ void __init plat_timer_setup(void) BUG(); } +static __init int cpu_has_mfc0_count_bug(void) +{ + switch (current_cpu_type()) { + case CPU_R4000PC: + case CPU_R4000SC: + case CPU_R4000MC: + /* + * V3.0 is documented as suffering from the mfc0 from count bug. + * Afaik this is the last version of the R4000. Later versions + * were marketed as R4400. + */ + return 1; + + case CPU_R4400PC: + case CPU_R4400SC: + case CPU_R4400MC: + /* + * The published errata for the R4400 upto 3.0 say the CPU + * has the mfc0 from count bug. + */ + if ((current_cpu_data.processor_id & 0xff) <= 0x30) + return 1; + + /* + * I don't have erratas for newer R4400 so be paranoid. + */ + return 1; + } + + return 0; +} + void __init time_init(void) { plat_time_init(); - if (cpu_has_counter && (mips_hpt_frequency || mips_timer_state)) { - /* We know counter frequency. Or we can get it. */ - if (!mips_hpt_frequency) - mips_hpt_frequency = calibrate_hpt(); - - /* Report the high precision timer rate for a reference. */ - printk("Using %u.%03u MHz high precision timer.\n", - ((mips_hpt_frequency + 500) / 1000) / 1000, - ((mips_hpt_frequency + 500) / 1000) % 1000); + if (mips_clockevent_init() || !cpu_has_mfc0_count_bug()) init_mips_clocksource(); - } - - mips_clockevent_init(); } diff --git a/include/asm-mips/time.h b/include/asm-mips/time.h index ee1663e64da1..1922494a0d9e 100644 --- a/include/asm-mips/time.h +++ b/include/asm-mips/time.h @@ -58,11 +58,12 @@ extern int (*perf_irq)(void); * Initialize the calling CPU's compare interrupt as clockevent device */ #ifdef CONFIG_CEVT_R4K -extern void mips_clockevent_init(void); +extern int mips_clockevent_init(void); extern unsigned int __weak get_c0_compare_int(void); #else -static inline void mips_clockevent_init(void) +static inline int mips_clockevent_init(void) { + return -ENXIO; } #endif |