diff options
Diffstat (limited to 'arch/mips/mti-malta/malta-time.c')
| -rw-r--r-- | arch/mips/mti-malta/malta-time.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/arch/mips/mti-malta/malta-time.c b/arch/mips/mti-malta/malta-time.c new file mode 100644 index 00000000000..0b97d47691f --- /dev/null +++ b/arch/mips/mti-malta/malta-time.c @@ -0,0 +1,163 @@ +/* + * 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/init.h> +#include <linux/kernel_stat.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <linux/time.h> +#include <linux/timex.h> +#include <linux/mc146818rtc.h> + +#include <asm/mipsregs.h> +#include <asm/mipsmtregs.h> +#include <asm/hardirq.h> +#include <asm/i8253.h> +#include <asm/irq.h> +#include <asm/div64.h> +#include <asm/cpu.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/prom.h> + +#include <asm/mips-boards/maltaint.h> + +unsigned long cpu_khz; + +static int mips_cpu_timer_irq; +static int mips_cpu_perf_irq; +extern int cp0_perfcount_irq; + +static void mips_timer_dispatch(void) +{ + do_IRQ(mips_cpu_timer_irq); +} + +static void mips_perf_dispatch(void) +{ + do_IRQ(mips_cpu_perf_irq); +} + +/* + * Estimate CPU frequency. Sets mips_hpt_frequency as a side-effect + */ +static unsigned int __init estimate_cpu_frequency(void) +{ + unsigned int prid = read_c0_prid() & 0xffff00; + unsigned int count; + + unsigned long flags; + unsigned int start; + + 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)); + + /* Start r4k counter. */ + start = read_c0_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() - start; + + /* restore interrupts */ + local_irq_restore(flags); + + mips_hpt_frequency = count; + if ((prid != (PRID_COMP_MIPS | PRID_IMP_20KC)) && + (prid != (PRID_COMP_MIPS | PRID_IMP_25KF))) + count *= 2; + + count += 5000; /* round */ + count -= count%10000; + + return count; +} + +unsigned long read_persistent_clock(void) +{ + return mc146818_get_cmos_time(); +} + +static void __init plat_perf_setup(void) +{ +#ifdef MSC01E_INT_BASE + if (cpu_has_veic) { + set_vi_handler(MSC01E_INT_PERFCTR, mips_perf_dispatch); + mips_cpu_perf_irq = MSC01E_INT_BASE + MSC01E_INT_PERFCTR; + } else +#endif + if (cp0_perfcount_irq >= 0) { + if (cpu_has_vint) + set_vi_handler(cp0_perfcount_irq, mips_perf_dispatch); + mips_cpu_perf_irq = MIPS_CPU_IRQ_BASE + cp0_perfcount_irq; +#ifdef CONFIG_SMP + set_irq_handler(mips_cpu_perf_irq, handle_percpu_irq); +#endif + } +} + +unsigned int __cpuinit get_c0_compare_int(void) +{ +#ifdef MSC01E_INT_BASE + if (cpu_has_veic) { + set_vi_handler(MSC01E_INT_CPUCTR, mips_timer_dispatch); + mips_cpu_timer_irq = MSC01E_INT_BASE + MSC01E_INT_CPUCTR; + } else +#endif + { + if (cpu_has_vint) + set_vi_handler(cp0_compare_irq, mips_timer_dispatch); + mips_cpu_timer_irq = MIPS_CPU_IRQ_BASE + cp0_compare_irq; + } + + return mips_cpu_timer_irq; +} + +void __init plat_time_init(void) +{ + unsigned int est_freq; + + /* Set Data mode - binary. */ + CMOS_WRITE(CMOS_READ(RTC_CONTROL) | RTC_DM_BINARY, RTC_CONTROL); + + est_freq = estimate_cpu_frequency(); + + printk("CPU frequency %d.%02d MHz\n", est_freq/1000000, + (est_freq%1000000)*100/1000000); + + cpu_khz = est_freq / 1000; + + mips_scroll_message(); +#ifdef CONFIG_I8253 /* Only Malta has a PIT */ + setup_pit_timer(); +#endif + + plat_perf_setup(); +} |