diff options
Diffstat (limited to 'arch/ppc64/kernel/time.c')
| -rw-r--r-- | arch/ppc64/kernel/time.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/time.c b/arch/ppc64/kernel/time.c index 33364a7d2cd2e..2348a75e050dc 100644 --- a/arch/ppc64/kernel/time.c +++ b/arch/ppc64/kernel/time.c @@ -107,6 +107,9 @@ void ppc_adjtimex(void); static unsigned adjusting_time = 0; +unsigned long ppc_proc_freq; +unsigned long ppc_tb_freq; + static __inline__ void timer_check_rtc(void) { /* @@ -472,6 +475,66 @@ int do_settimeofday(struct timespec *tv) EXPORT_SYMBOL(do_settimeofday); +#if defined(CONFIG_PPC_PSERIES) || defined(CONFIG_PPC_MAPLE) || defined(CONFIG_PPC_BPA) +void __init generic_calibrate_decr(void) +{ + struct device_node *cpu; + struct div_result divres; + unsigned int *fp; + int node_found; + + /* + * The cpu node should have a timebase-frequency property + * to tell us the rate at which the decrementer counts. + */ + cpu = of_find_node_by_type(NULL, "cpu"); + + ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */ + node_found = 0; + if (cpu != 0) { + fp = (unsigned int *)get_property(cpu, "timebase-frequency", + NULL); + if (fp != 0) { + node_found = 1; + ppc_tb_freq = *fp; + } + } + if (!node_found) + printk(KERN_ERR "WARNING: Estimating decrementer frequency " + "(not found)\n"); + + ppc_proc_freq = DEFAULT_PROC_FREQ; + node_found = 0; + if (cpu != 0) { + fp = (unsigned int *)get_property(cpu, "clock-frequency", + NULL); + if (fp != 0) { + node_found = 1; + ppc_proc_freq = *fp; + } + } + if (!node_found) + printk(KERN_ERR "WARNING: Estimating processor frequency " + "(not found)\n"); + + of_node_put(cpu); + + printk(KERN_INFO "time_init: decrementer frequency = %lu.%.6lu MHz\n", + ppc_tb_freq/1000000, ppc_tb_freq%1000000); + printk(KERN_INFO "time_init: processor frequency = %lu.%.6lu MHz\n", + ppc_proc_freq/1000000, ppc_proc_freq%1000000); + + tb_ticks_per_jiffy = ppc_tb_freq / HZ; + tb_ticks_per_sec = tb_ticks_per_jiffy * HZ; + tb_ticks_per_usec = ppc_tb_freq / 1000000; + tb_to_us = mulhwu_scale_factor(ppc_tb_freq, 1000000); + div128_by_32(1024*1024, 0, tb_ticks_per_sec, &divres); + tb_to_xs = divres.result_low; + + setup_default_decr(); +} +#endif + void __init time_init(void) { /* This function is only called on the boot processor */ |