diff options
Diffstat (limited to 'kernel/arch/mips/mti-malta/malta-time.c')
| -rw-r--r-- | kernel/arch/mips/mti-malta/malta-time.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/kernel/arch/mips/mti-malta/malta-time.c b/kernel/arch/mips/mti-malta/malta-time.c new file mode 100644 index 000000000..185e68261 --- /dev/null +++ b/kernel/arch/mips/mti-malta/malta-time.c @@ -0,0 +1,211 @@ +/* + * Carsten Langgaard, carstenl@mips.com + * Copyright (C) 1999,2000 MIPS Technologies, Inc. All rights reserved. + * + * This program is free software; you can distribute it and/or modify it + * under the terms of the GNU General Public License (Version 2) as + * published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. + * + * Setting up the clock on the MIPS boards. + */ +#include <linux/types.h> +#include <linux/i8253.h> +#include <linux/init.h> +#include <linux/kernel_stat.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <linux/irqchip/mips-gic.h> +#include <linux/timex.h> +#include <linux/mc146818rtc.h> + +#include <asm/cpu.h> +#include <asm/mipsregs.h> +#include <asm/mipsmtregs.h> +#include <asm/hardirq.h> +#include <asm/irq.h> +#include <asm/div64.h> +#include <asm/setup.h> +#include <asm/time.h> +#include <asm/mc146818-time.h> +#include <asm/msc01_ic.h> + +#include <asm/mips-boards/generic.h> +#include <asm/mips-boards/maltaint.h> + +static int mips_cpu_timer_irq; +static int mips_cpu_perf_irq; +extern int cp0_perfcount_irq; + +static unsigned int gic_frequency; + +static void mips_timer_dispatch(void) +{ + do_IRQ(mips_cpu_timer_irq); +} + +static void mips_perf_dispatch(void) +{ + do_IRQ(mips_cpu_perf_irq); +} + +static unsigned int freqround(unsigned int freq, unsigned int amount) +{ + freq += amount; + freq -= freq % (amount*2); + return freq; +} + +/* + * Estimate CPU and GIC frequencies. + */ +static void __init estimate_frequencies(void) +{ + unsigned long flags; + unsigned int count, start; + cycle_t giccount = 0, gicstart = 0; + +#if defined(CONFIG_KVM_GUEST) && CONFIG_KVM_GUEST_TIMER_FREQ + mips_hpt_frequency = CONFIG_KVM_GUEST_TIMER_FREQ * 1000000; + return; +#endif + + local_irq_save(flags); + + /* Start counter exactly on falling edge of update flag. */ + while (CMOS_READ(RTC_REG_A) & RTC_UIP); + while (!(CMOS_READ(RTC_REG_A) & RTC_UIP)); + + /* Initialize counters. */ + start = read_c0_count(); + if (gic_present) { + gic_start_count(); + gicstart = gic_read_count(); + } + + /* Read counter exactly on falling edge of update flag. */ + while (CMOS_READ(RTC_REG_A) & RTC_UIP); + while (!(CMOS_READ(RTC_REG_A) & RTC_UIP)); + + count = read_c0_count(); + if (gic_present) + giccount = gic_read_count(); + + local_irq_restore(flags); + + count -= start; + mips_hpt_frequency = count; + + if (gic_present) { + giccount -= gicstart; + gic_frequency = giccount; + } +} + +void read_persistent_clock(struct timespec *ts) +{ + ts->tv_sec = mc146818_get_cmos_time(); + ts->tv_nsec = 0; +} + +int get_c0_fdc_int(void) +{ + int mips_cpu_fdc_irq; + + if (cpu_has_veic) + mips_cpu_fdc_irq = -1; + else if (gic_present) + mips_cpu_fdc_irq = gic_get_c0_fdc_int(); + else if (cp0_fdc_irq >= 0) + mips_cpu_fdc_irq = MIPS_CPU_IRQ_BASE + cp0_fdc_irq; + else + mips_cpu_fdc_irq = -1; + + return mips_cpu_fdc_irq; +} + +int get_c0_perfcount_int(void) +{ + if (cpu_has_veic) { + set_vi_handler(MSC01E_INT_PERFCTR, mips_perf_dispatch); + mips_cpu_perf_irq = MSC01E_INT_BASE + MSC01E_INT_PERFCTR; + } else if (gic_present) { + mips_cpu_perf_irq = gic_get_c0_perfcount_int(); + } else if (cp0_perfcount_irq >= 0) { + mips_cpu_perf_irq = MIPS_CPU_IRQ_BASE + cp0_perfcount_irq; + } else { + mips_cpu_perf_irq = -1; + } + + return mips_cpu_perf_irq; +} + +unsigned int get_c0_compare_int(void) +{ + if (cpu_has_veic) { + set_vi_handler(MSC01E_INT_CPUCTR, mips_timer_dispatch); + mips_cpu_timer_irq = MSC01E_INT_BASE + MSC01E_INT_CPUCTR; + } else if (gic_present) { + mips_cpu_timer_irq = gic_get_c0_compare_int(); + } else { + mips_cpu_timer_irq = MIPS_CPU_IRQ_BASE + cp0_compare_irq; + } + + return mips_cpu_timer_irq; +} + +static void __init init_rtc(void) +{ + /* stop the clock whilst setting it up */ + CMOS_WRITE(RTC_SET | RTC_24H, RTC_CONTROL); + + /* 32KHz time base */ + CMOS_WRITE(RTC_REF_CLCK_32KHZ, RTC_FREQ_SELECT); + + /* start the clock */ + CMOS_WRITE(RTC_24H, RTC_CONTROL); +} + +void __init plat_time_init(void) +{ + unsigned int prid = read_c0_prid() & (PRID_COMP_MASK | PRID_IMP_MASK); + unsigned int freq; + + init_rtc(); + estimate_frequencies(); + + freq = mips_hpt_frequency; + if ((prid != (PRID_COMP_MIPS | PRID_IMP_20KC)) && + (prid != (PRID_COMP_MIPS | PRID_IMP_25KF))) + freq *= 2; + freq = freqround(freq, 5000); + printk("CPU frequency %d.%02d MHz\n", freq/1000000, + (freq%1000000)*100/1000000); + + mips_scroll_message(); + +#ifdef CONFIG_I8253 + /* Only Malta has a PIT. */ + setup_pit_timer(); +#endif + +#ifdef CONFIG_MIPS_GIC + if (gic_present) { + freq = freqround(gic_frequency, 5000); + printk("GIC frequency %d.%02d MHz\n", freq/1000000, + (freq%1000000)*100/1000000); +#ifdef CONFIG_CLKSRC_MIPS_GIC + gic_clocksource_init(gic_frequency); +#endif + } +#endif +} |