Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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/config.h> |
| 23 | #include <linux/init.h> |
| 24 | #include <linux/kernel_stat.h> |
| 25 | #include <linux/sched.h> |
| 26 | #include <linux/spinlock.h> |
| 27 | #include <linux/interrupt.h> |
| 28 | #include <linux/time.h> |
| 29 | #include <linux/timex.h> |
| 30 | #include <linux/mc146818rtc.h> |
| 31 | |
| 32 | #include <asm/mipsregs.h> |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 33 | #include <asm/mipsmtregs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | #include <asm/ptrace.h> |
Ralf Baechle | e01402b | 2005-07-14 15:57:16 +0000 | [diff] [blame] | 35 | #include <asm/hardirq.h> |
| 36 | #include <asm/irq.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | #include <asm/div64.h> |
| 38 | #include <asm/cpu.h> |
| 39 | #include <asm/time.h> |
| 40 | #include <asm/mc146818-time.h> |
Ralf Baechle | e01402b | 2005-07-14 15:57:16 +0000 | [diff] [blame] | 41 | #include <asm/msc01_ic.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | |
| 43 | #include <asm/mips-boards/generic.h> |
| 44 | #include <asm/mips-boards/prom.h> |
Ralf Baechle | e01402b | 2005-07-14 15:57:16 +0000 | [diff] [blame] | 45 | #include <asm/mips-boards/maltaint.h> |
| 46 | #include <asm/mc146818-time.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | |
| 48 | unsigned long cpu_khz; |
| 49 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | #if defined(CONFIG_MIPS_ATLAS) |
| 51 | static char display_string[] = " LINUX ON ATLAS "; |
| 52 | #endif |
| 53 | #if defined(CONFIG_MIPS_MALTA) |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 54 | #if defined(CONFIG_MIPS_MT_SMTC) |
| 55 | static char display_string[] = " SMTC LINUX ON MALTA "; |
| 56 | #else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | static char display_string[] = " LINUX ON MALTA "; |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 58 | #endif /* CONFIG_MIPS_MT_SMTC */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | #endif |
| 60 | #if defined(CONFIG_MIPS_SEAD) |
| 61 | static char display_string[] = " LINUX ON SEAD "; |
| 62 | #endif |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 63 | static unsigned int display_count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | #define MAX_DISPLAY_COUNT (sizeof(display_string) - 8) |
| 65 | |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 66 | #define CPUCTR_IMASKBIT (0x100 << MIPSCPU_INT_CPUCTR) |
| 67 | |
| 68 | static unsigned int timer_tick_count; |
Ralf Baechle | e01402b | 2005-07-14 15:57:16 +0000 | [diff] [blame] | 69 | static int mips_cpu_timer_irq; |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 70 | extern void smtc_timer_broadcast(int); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | |
Ralf Baechle | 340ee4b | 2005-08-17 17:44:08 +0000 | [diff] [blame] | 72 | static inline void scroll_display_message(void) |
| 73 | { |
| 74 | if ((timer_tick_count++ % HZ) == 0) { |
| 75 | mips_display_message(&display_string[display_count++]); |
| 76 | if (display_count == MAX_DISPLAY_COUNT) |
| 77 | display_count = 0; |
| 78 | } |
| 79 | } |
| 80 | |
Ralf Baechle | e01402b | 2005-07-14 15:57:16 +0000 | [diff] [blame] | 81 | static void mips_timer_dispatch (struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | { |
Ralf Baechle | e01402b | 2005-07-14 15:57:16 +0000 | [diff] [blame] | 83 | do_IRQ (mips_cpu_timer_irq, regs); |
| 84 | } |
| 85 | |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 86 | /* |
| 87 | * Redeclare until I get around mopping the timer code insanity on MIPS. |
| 88 | */ |
Ralf Baechle | ba339c0 | 2005-12-09 12:29:38 +0000 | [diff] [blame] | 89 | extern int null_perf_irq(struct pt_regs *regs); |
| 90 | |
| 91 | extern int (*perf_irq)(struct pt_regs *regs); |
| 92 | |
Ralf Baechle | e01402b | 2005-07-14 15:57:16 +0000 | [diff] [blame] | 93 | irqreturn_t mips_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) |
| 94 | { |
Ralf Baechle | 340ee4b | 2005-08-17 17:44:08 +0000 | [diff] [blame] | 95 | int cpu = smp_processor_id(); |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 96 | int r2 = cpu_has_mips_r2; |
Ralf Baechle | 340ee4b | 2005-08-17 17:44:08 +0000 | [diff] [blame] | 97 | |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 98 | #ifdef CONFIG_MIPS_MT_SMTC |
| 99 | /* |
| 100 | * In an SMTC system, one Count/Compare set exists per VPE. |
| 101 | * Which TC within a VPE gets the interrupt is essentially |
| 102 | * random - we only know that it shouldn't be one with |
| 103 | * IXMT set. Whichever TC gets the interrupt needs to |
| 104 | * send special interprocessor interrupts to the other |
| 105 | * TCs to make sure that they schedule, etc. |
| 106 | * |
| 107 | * That code is specific to the SMTC kernel, not to |
| 108 | * the a particular platform, so it's invoked from |
| 109 | * the general MIPS timer_interrupt routine. |
| 110 | */ |
| 111 | |
| 112 | /* |
| 113 | * DVPE is necessary so long as cross-VPE interrupts |
| 114 | * are done via read-modify-write of Cause register. |
| 115 | */ |
| 116 | int vpflags = dvpe(); |
| 117 | write_c0_compare (read_c0_count() - 1); |
| 118 | clear_c0_cause(CPUCTR_IMASKBIT); |
| 119 | evpe(vpflags); |
| 120 | |
| 121 | if (cpu_data[cpu].vpe_id == 0) { |
| 122 | timer_interrupt(irq, dev_id, regs); |
| 123 | scroll_display_message(); |
| 124 | } else |
| 125 | write_c0_compare (read_c0_count() + ( mips_hpt_frequency/HZ)); |
| 126 | smtc_timer_broadcast(cpu_data[cpu].vpe_id); |
| 127 | |
| 128 | if (cpu != 0) |
| 129 | /* |
| 130 | * Other CPUs should do profiling and process accounting |
| 131 | */ |
| 132 | local_timer_interrupt(irq, dev_id, regs); |
| 133 | |
| 134 | #else /* CONFIG_MIPS_MT_SMTC */ |
Ralf Baechle | 340ee4b | 2005-08-17 17:44:08 +0000 | [diff] [blame] | 135 | if (cpu == 0) { |
| 136 | /* |
Ralf Baechle | ba339c0 | 2005-12-09 12:29:38 +0000 | [diff] [blame] | 137 | * CPU 0 handles the global timer interrupt job and process |
| 138 | * accounting resets count/compare registers to trigger next |
| 139 | * timer int. |
Ralf Baechle | 340ee4b | 2005-08-17 17:44:08 +0000 | [diff] [blame] | 140 | */ |
Ralf Baechle | ba339c0 | 2005-12-09 12:29:38 +0000 | [diff] [blame] | 141 | if (!r2 || (read_c0_cause() & (1 << 26))) |
| 142 | if (perf_irq(regs)) |
| 143 | goto out; |
| 144 | |
| 145 | /* we keep interrupt disabled all the time */ |
| 146 | if (!r2 || (read_c0_cause() & (1 << 30))) |
| 147 | timer_interrupt(irq, NULL, regs); |
| 148 | |
Ralf Baechle | 340ee4b | 2005-08-17 17:44:08 +0000 | [diff] [blame] | 149 | scroll_display_message(); |
Ralf Baechle | 11e6df6 | 2005-12-09 12:09:22 +0000 | [diff] [blame] | 150 | } else { |
Ralf Baechle | 340ee4b | 2005-08-17 17:44:08 +0000 | [diff] [blame] | 151 | /* Everyone else needs to reset the timer int here as |
| 152 | ll_local_timer_interrupt doesn't */ |
| 153 | /* |
| 154 | * FIXME: need to cope with counter underflow. |
| 155 | * More support needs to be added to kernel/time for |
| 156 | * counter/timer interrupts on multiple CPU's |
| 157 | */ |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 158 | write_c0_compare(read_c0_count() + (mips_hpt_frequency/HZ)); |
| 159 | |
Ralf Baechle | 340ee4b | 2005-08-17 17:44:08 +0000 | [diff] [blame] | 160 | /* |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 161 | * Other CPUs should do profiling and process accounting |
Ralf Baechle | 340ee4b | 2005-08-17 17:44:08 +0000 | [diff] [blame] | 162 | */ |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 163 | local_timer_interrupt(irq, dev_id, regs); |
Ralf Baechle | 340ee4b | 2005-08-17 17:44:08 +0000 | [diff] [blame] | 164 | } |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 165 | #endif /* CONFIG_MIPS_MT_SMTC */ |
Ralf Baechle | 340ee4b | 2005-08-17 17:44:08 +0000 | [diff] [blame] | 166 | |
Ralf Baechle | ba339c0 | 2005-12-09 12:29:38 +0000 | [diff] [blame] | 167 | out: |
Ralf Baechle | 340ee4b | 2005-08-17 17:44:08 +0000 | [diff] [blame] | 168 | return IRQ_HANDLED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | } |
| 170 | |
| 171 | /* |
| 172 | * Estimate CPU frequency. Sets mips_counter_frequency as a side-effect |
| 173 | */ |
| 174 | static unsigned int __init estimate_cpu_frequency(void) |
| 175 | { |
| 176 | unsigned int prid = read_c0_prid() & 0xffff00; |
| 177 | unsigned int count; |
| 178 | |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 179 | #if defined(CONFIG_MIPS_SEAD) || defined(CONFIG_MIPS_SIM) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | /* |
| 181 | * The SEAD board doesn't have a real time clock, so we can't |
| 182 | * really calculate the timer frequency |
| 183 | * For now we hardwire the SEAD board frequency to 12MHz. |
| 184 | */ |
Ralf Baechle | 42a3b4f | 2005-09-03 15:56:17 -0700 | [diff] [blame] | 185 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | if ((prid == (PRID_COMP_MIPS | PRID_IMP_20KC)) || |
| 187 | (prid == (PRID_COMP_MIPS | PRID_IMP_25KF))) |
| 188 | count = 12000000; |
| 189 | else |
| 190 | count = 6000000; |
| 191 | #endif |
| 192 | #if defined(CONFIG_MIPS_ATLAS) || defined(CONFIG_MIPS_MALTA) |
| 193 | unsigned int flags; |
| 194 | |
| 195 | local_irq_save(flags); |
| 196 | |
| 197 | /* Start counter exactly on falling edge of update flag */ |
| 198 | while (CMOS_READ(RTC_REG_A) & RTC_UIP); |
| 199 | while (!(CMOS_READ(RTC_REG_A) & RTC_UIP)); |
| 200 | |
| 201 | /* Start r4k counter. */ |
| 202 | write_c0_count(0); |
| 203 | |
| 204 | /* Read counter exactly on falling edge of update flag */ |
| 205 | while (CMOS_READ(RTC_REG_A) & RTC_UIP); |
| 206 | while (!(CMOS_READ(RTC_REG_A) & RTC_UIP)); |
| 207 | |
| 208 | count = read_c0_count(); |
| 209 | |
| 210 | /* restore interrupts */ |
| 211 | local_irq_restore(flags); |
| 212 | #endif |
| 213 | |
| 214 | mips_hpt_frequency = count; |
| 215 | if ((prid != (PRID_COMP_MIPS | PRID_IMP_20KC)) && |
| 216 | (prid != (PRID_COMP_MIPS | PRID_IMP_25KF))) |
| 217 | count *= 2; |
| 218 | |
| 219 | count += 5000; /* round */ |
| 220 | count -= count%10000; |
| 221 | |
| 222 | return count; |
| 223 | } |
| 224 | |
| 225 | unsigned long __init mips_rtc_get_time(void) |
| 226 | { |
| 227 | return mc146818_get_cmos_time(); |
| 228 | } |
| 229 | |
| 230 | void __init mips_time_init(void) |
| 231 | { |
| 232 | unsigned int est_freq, flags; |
| 233 | |
| 234 | local_irq_save(flags); |
| 235 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | /* Set Data mode - binary. */ |
| 237 | CMOS_WRITE(CMOS_READ(RTC_CONTROL) | RTC_DM_BINARY, RTC_CONTROL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | |
| 239 | est_freq = estimate_cpu_frequency (); |
| 240 | |
| 241 | printk("CPU frequency %d.%02d MHz\n", est_freq/1000000, |
| 242 | (est_freq%1000000)*100/1000000); |
| 243 | |
| 244 | cpu_khz = est_freq / 1000; |
| 245 | |
| 246 | local_irq_restore(flags); |
| 247 | } |
| 248 | |
| 249 | void __init mips_timer_setup(struct irqaction *irq) |
| 250 | { |
Ralf Baechle | e01402b | 2005-07-14 15:57:16 +0000 | [diff] [blame] | 251 | if (cpu_has_veic) { |
| 252 | set_vi_handler (MSC01E_INT_CPUCTR, mips_timer_dispatch); |
| 253 | mips_cpu_timer_irq = MSC01E_INT_BASE + MSC01E_INT_CPUCTR; |
| 254 | } |
| 255 | else { |
| 256 | if (cpu_has_vint) |
| 257 | set_vi_handler (MIPSCPU_INT_CPUCTR, mips_timer_dispatch); |
| 258 | mips_cpu_timer_irq = MIPSCPU_INT_BASE + MIPSCPU_INT_CPUCTR; |
| 259 | } |
| 260 | |
| 261 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | /* we are using the cpu counter for timer interrupts */ |
Ralf Baechle | e01402b | 2005-07-14 15:57:16 +0000 | [diff] [blame] | 263 | irq->handler = mips_timer_interrupt; /* we use our own handler */ |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 264 | #ifdef CONFIG_MIPS_MT_SMTC |
| 265 | setup_irq_smtc(mips_cpu_timer_irq, irq, CPUCTR_IMASKBIT); |
| 266 | #else |
Ralf Baechle | e01402b | 2005-07-14 15:57:16 +0000 | [diff] [blame] | 267 | setup_irq(mips_cpu_timer_irq, irq); |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 268 | #endif /* CONFIG_MIPS_MT_SMTC */ |
Ralf Baechle | e01402b | 2005-07-14 15:57:16 +0000 | [diff] [blame] | 269 | |
Ralf Baechle | 340ee4b | 2005-08-17 17:44:08 +0000 | [diff] [blame] | 270 | #ifdef CONFIG_SMP |
| 271 | /* irq_desc(riptor) is a global resource, when the interrupt overlaps |
| 272 | on seperate cpu's the first one tries to handle the second interrupt. |
| 273 | The effect is that the int remains disabled on the second cpu. |
| 274 | Mark the interrupt with IRQ_PER_CPU to avoid any confusion */ |
| 275 | irq_desc[mips_cpu_timer_irq].status |= IRQ_PER_CPU; |
| 276 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | |
| 278 | /* to generate the first timer interrupt */ |
| 279 | write_c0_compare (read_c0_count() + mips_hpt_frequency/HZ); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | } |