Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 1 | /* |
| 2 | * arch/xtensa/kernel/time.c |
| 3 | * |
| 4 | * Timer and clock support. |
| 5 | * |
| 6 | * This file is subject to the terms and conditions of the GNU General Public |
| 7 | * License. See the file "COPYING" in the main directory of this archive |
| 8 | * for more details. |
| 9 | * |
| 10 | * Copyright (C) 2005 Tensilica Inc. |
| 11 | * |
| 12 | * Chris Zankel <chris@zankel.net> |
| 13 | */ |
| 14 | |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 15 | #include <linux/errno.h> |
Alexey Dobriyan | d43c36d | 2009-10-07 17:09:06 +0400 | [diff] [blame] | 16 | #include <linux/sched.h> |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 17 | #include <linux/time.h> |
Johannes Weiner | fcc8f0f | 2009-03-04 21:39:12 +0100 | [diff] [blame] | 18 | #include <linux/clocksource.h> |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 19 | #include <linux/interrupt.h> |
| 20 | #include <linux/module.h> |
| 21 | #include <linux/init.h> |
| 22 | #include <linux/irq.h> |
| 23 | #include <linux/profile.h> |
| 24 | #include <linux/delay.h> |
| 25 | |
| 26 | #include <asm/timex.h> |
| 27 | #include <asm/platform.h> |
| 28 | |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 29 | #ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT |
| 30 | unsigned long ccount_per_jiffy; /* per 1/HZ */ |
Chris Zankel | 2b8aea7 | 2007-08-05 10:26:30 -0700 | [diff] [blame] | 31 | unsigned long nsec_per_ccount; /* nsec per ccount increment */ |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 32 | #endif |
| 33 | |
Johannes Weiner | fcc8f0f | 2009-03-04 21:39:12 +0100 | [diff] [blame] | 34 | static cycle_t ccount_read(void) |
| 35 | { |
| 36 | return (cycle_t)get_ccount(); |
| 37 | } |
| 38 | |
| 39 | static struct clocksource ccount_clocksource = { |
| 40 | .name = "ccount", |
| 41 | .rating = 200, |
| 42 | .read = ccount_read, |
| 43 | .mask = CLOCKSOURCE_MASK(32), |
Johannes Weiner | fcc8f0f | 2009-03-04 21:39:12 +0100 | [diff] [blame] | 44 | }; |
| 45 | |
Chris Zankel | fd43fe1 | 2006-12-10 02:18:47 -0800 | [diff] [blame] | 46 | static irqreturn_t timer_interrupt(int irq, void *dev_id); |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 47 | static struct irqaction timer_irqaction = { |
| 48 | .handler = timer_interrupt, |
Thomas Gleixner | 85ac3ab | 2006-07-01 19:29:31 -0700 | [diff] [blame] | 49 | .flags = IRQF_DISABLED, |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 50 | .name = "timer", |
| 51 | }; |
| 52 | |
| 53 | void __init time_init(void) |
| 54 | { |
Chris Zankel | 288a60c | 2005-09-22 21:44:23 -0700 | [diff] [blame] | 55 | #ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 56 | printk("Calibrating CPU frequency "); |
| 57 | platform_calibrate_ccount(); |
| 58 | printk("%d.%02d MHz\n", (int)ccount_per_jiffy/(1000000/HZ), |
| 59 | (int)(ccount_per_jiffy/(10000/HZ))%100); |
| 60 | #endif |
John Stultz | a139723 | 2010-04-26 20:25:56 -0700 | [diff] [blame] | 61 | clocksource_register_hz(&ccount_clocksource, CCOUNT_PER_JIFFY * HZ); |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 62 | |
| 63 | /* Initialize the linux timer interrupt. */ |
| 64 | |
| 65 | setup_irq(LINUX_TIMER_INT, &timer_irqaction); |
| 66 | set_linux_timer(get_ccount() + CCOUNT_PER_JIFFY); |
| 67 | } |
| 68 | |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 69 | /* |
| 70 | * The timer interrupt is called HZ times per second. |
| 71 | */ |
| 72 | |
Chris Zankel | fd43fe1 | 2006-12-10 02:18:47 -0800 | [diff] [blame] | 73 | irqreturn_t timer_interrupt (int irq, void *dev_id) |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 74 | { |
| 75 | |
| 76 | unsigned long next; |
| 77 | |
| 78 | next = get_linux_timer(); |
| 79 | |
| 80 | again: |
| 81 | while ((signed long)(get_ccount() - next) > 0) { |
| 82 | |
Chris Zankel | fd43fe1 | 2006-12-10 02:18:47 -0800 | [diff] [blame] | 83 | profile_tick(CPU_PROFILING); |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 84 | #ifndef CONFIG_SMP |
Chris Zankel | fd43fe1 | 2006-12-10 02:18:47 -0800 | [diff] [blame] | 85 | update_process_times(user_mode(get_irq_regs())); |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 86 | #endif |
| 87 | |
Torben Hohn | d12b0e2 | 2011-01-27 16:00:27 +0100 | [diff] [blame] | 88 | xtime_update(1); /* Linux handler in kernel/time/timekeeping */ |
Chris Zankel | 2b8aea7 | 2007-08-05 10:26:30 -0700 | [diff] [blame] | 89 | |
| 90 | /* Note that writing CCOMPARE clears the interrupt. */ |
| 91 | |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 92 | next += CCOUNT_PER_JIFFY; |
Chris Zankel | 2b8aea7 | 2007-08-05 10:26:30 -0700 | [diff] [blame] | 93 | set_linux_timer(next); |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 94 | } |
| 95 | |
Chris Zankel | 2b8aea7 | 2007-08-05 10:26:30 -0700 | [diff] [blame] | 96 | /* Allow platform to do something useful (Wdog). */ |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 97 | |
Chris Zankel | 2b8aea7 | 2007-08-05 10:26:30 -0700 | [diff] [blame] | 98 | platform_heartbeat(); |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 99 | |
| 100 | /* Make sure we didn't miss any tick... */ |
| 101 | |
| 102 | if ((signed long)(get_ccount() - next) > 0) |
| 103 | goto again; |
| 104 | |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 105 | return IRQ_HANDLED; |
| 106 | } |
| 107 | |
| 108 | #ifndef CONFIG_GENERIC_CALIBRATE_DELAY |
Adrian Bunk | 6c81c32 | 2008-02-06 01:37:51 -0800 | [diff] [blame] | 109 | void __cpuinit calibrate_delay(void) |
Chris Zankel | 5a0015d | 2005-06-23 22:01:16 -0700 | [diff] [blame] | 110 | { |
| 111 | loops_per_jiffy = CCOUNT_PER_JIFFY; |
| 112 | printk("Calibrating delay loop (skipped)... " |
| 113 | "%lu.%02lu BogoMIPS preset\n", |
| 114 | loops_per_jiffy/(1000000/HZ), |
| 115 | (loops_per_jiffy/(10000/HZ)) % 100); |
| 116 | } |
| 117 | #endif |