1/* 2 * Carsten Langgaard, carstenl@mips.com 3 * Copyright (C) 1999,2000 MIPS Technologies, Inc. All rights reserved. 4 * 5 * This program is free software; you can distribute it and/or modify it 6 * under the terms of the GNU General Public License (Version 2) as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * for more details. 13 * 14 * You should have received a copy of the GNU General Public License along 15 * with this program; if not, write to the Free Software Foundation, Inc., 16 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. 17 * 18 * Setting up the clock on the MIPS boards. 19 */ 20 21#include <linux/types.h> 22#include <linux/init.h> 23#include <linux/kernel_stat.h> 24#include <linux/sched.h> 25#include <linux/spinlock.h> 26#include <linux/interrupt.h> 27#include <linux/time.h> 28#include <linux/timex.h> 29#include <linux/mc146818rtc.h> 30 31#include <asm/mipsregs.h> 32#include <asm/mipsmtregs.h> 33#include <asm/hardirq.h> 34#include <asm/i8253.h> 35#include <asm/irq.h> 36#include <asm/div64.h> 37#include <asm/cpu.h> 38#include <asm/time.h> 39#include <asm/mc146818-time.h> 40#include <asm/msc01_ic.h> 41#include <asm/gic.h> 42 43#include <asm/mips-boards/generic.h> 44#include <asm/mips-boards/prom.h> 45 46#include <asm/mips-boards/maltaint.h> 47 48unsigned long cpu_khz; 49 50static int mips_cpu_timer_irq; 51static int mips_cpu_perf_irq; 52extern int cp0_perfcount_irq; 53 54static void mips_timer_dispatch(void) 55{ 56 do_IRQ(mips_cpu_timer_irq); 57} 58 59static void mips_perf_dispatch(void) 60{ 61 do_IRQ(mips_cpu_perf_irq); 62} 63 64/* 65 * Estimate CPU frequency. Sets mips_hpt_frequency as a side-effect 66 */ 67static unsigned int __init estimate_cpu_frequency(void) 68{ 69 unsigned int prid = read_c0_prid() & 0xffff00; 70 unsigned int count; 71 72 unsigned long flags; 73 unsigned int start; 74 75 local_irq_save(flags); 76 77 /* Start counter exactly on falling edge of update flag */ 78 while (CMOS_READ(RTC_REG_A) & RTC_UIP); 79 while (!(CMOS_READ(RTC_REG_A) & RTC_UIP)); 80 81 /* Start r4k counter. */ 82 start = read_c0_count(); 83 84 /* Read counter exactly on falling edge of update flag */ 85 while (CMOS_READ(RTC_REG_A) & RTC_UIP); 86 while (!(CMOS_READ(RTC_REG_A) & RTC_UIP)); 87 88 count = read_c0_count() - start; 89 90 /* restore interrupts */ 91 local_irq_restore(flags); 92 93 mips_hpt_frequency = count; 94 if ((prid != (PRID_COMP_MIPS | PRID_IMP_20KC)) && 95 (prid != (PRID_COMP_MIPS | PRID_IMP_25KF))) 96 count *= 2; 97 98 count += 5000; /* round */ 99 count -= count%10000; 100 101 return count; 102} 103 104void read_persistent_clock(struct timespec *ts) 105{ 106 ts->tv_sec = mc146818_get_cmos_time(); 107 ts->tv_nsec = 0; 108} 109 110static void __init plat_perf_setup(void) 111{ 112#ifdef MSC01E_INT_BASE 113 if (cpu_has_veic) { 114 set_vi_handler(MSC01E_INT_PERFCTR, mips_perf_dispatch); 115 mips_cpu_perf_irq = MSC01E_INT_BASE + MSC01E_INT_PERFCTR; 116 } else 117#endif 118 if (cp0_perfcount_irq >= 0) { 119 if (cpu_has_vint) 120 set_vi_handler(cp0_perfcount_irq, mips_perf_dispatch); 121 mips_cpu_perf_irq = MIPS_CPU_IRQ_BASE + cp0_perfcount_irq; 122#ifdef CONFIG_SMP 123 set_irq_handler(mips_cpu_perf_irq, handle_percpu_irq); 124#endif 125 } 126} 127 128unsigned int __cpuinit get_c0_compare_int(void) 129{ 130#ifdef MSC01E_INT_BASE 131 if (cpu_has_veic) { 132 set_vi_handler(MSC01E_INT_CPUCTR, mips_timer_dispatch); 133 mips_cpu_timer_irq = MSC01E_INT_BASE + MSC01E_INT_CPUCTR; 134 } else 135#endif 136 { 137 if (cpu_has_vint) 138 set_vi_handler(cp0_compare_irq, mips_timer_dispatch); 139 mips_cpu_timer_irq = MIPS_CPU_IRQ_BASE + cp0_compare_irq; 140 } 141 142 return mips_cpu_timer_irq; 143} 144 145void __init plat_time_init(void) 146{ 147 unsigned int est_freq; 148 149 /* Set Data mode - binary. */ 150 CMOS_WRITE(CMOS_READ(RTC_CONTROL) | RTC_DM_BINARY, RTC_CONTROL); 151 152 est_freq = estimate_cpu_frequency(); 153 154 printk("CPU frequency %d.%02d MHz\n", est_freq/1000000, 155 (est_freq%1000000)*100/1000000); 156 157 cpu_khz = est_freq / 1000; 158 159 mips_scroll_message(); 160 161#ifdef CONFIG_I8253 /* Only Malta has a PIT */ 162 setup_pit_timer(); 163#endif 164 165#ifdef CONFIG_CSRC_GIC 166 gic_clocksource_init(); 167#endif 168 169 plat_perf_setup(); 170} 171