Mark Salter | 730c1fa | 2010-10-27 17:28:57 +0100 | [diff] [blame] | 1 | /* MN10300 clockevents |
| 2 | * |
| 3 | * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved. |
| 4 | * Written by Mark Salter (msalter@redhat.com) |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public Licence |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the Licence, or (at your option) any later version. |
| 10 | */ |
| 11 | #include <linux/clockchips.h> |
| 12 | #include <linux/interrupt.h> |
| 13 | #include <linux/percpu.h> |
| 14 | #include <linux/smp.h> |
| 15 | #include <asm/timex.h> |
| 16 | #include "internal.h" |
| 17 | |
| 18 | #ifdef CONFIG_SMP |
| 19 | #if (CONFIG_NR_CPUS > 2) && !defined(CONFIG_GEENERIC_CLOCKEVENTS_BROADCAST) |
| 20 | #error "This doesn't scale well! Need per-core local timers." |
| 21 | #endif |
| 22 | #else /* CONFIG_SMP */ |
| 23 | #define stop_jiffies_counter1() |
| 24 | #define reload_jiffies_counter1(x) |
| 25 | #define TMJC1IRQ TMJCIRQ |
| 26 | #endif |
| 27 | |
| 28 | |
| 29 | static int next_event(unsigned long delta, |
| 30 | struct clock_event_device *evt) |
| 31 | { |
| 32 | unsigned int cpu = smp_processor_id(); |
| 33 | |
| 34 | if (cpu == 0) { |
| 35 | stop_jiffies_counter(); |
| 36 | reload_jiffies_counter(delta - 1); |
| 37 | } else { |
| 38 | stop_jiffies_counter1(); |
| 39 | reload_jiffies_counter1(delta - 1); |
| 40 | } |
| 41 | return 0; |
| 42 | } |
| 43 | |
| 44 | static void set_clock_mode(enum clock_event_mode mode, |
| 45 | struct clock_event_device *evt) |
| 46 | { |
| 47 | /* Nothing to do ... */ |
| 48 | } |
| 49 | |
| 50 | static DEFINE_PER_CPU(struct clock_event_device, mn10300_clockevent_device); |
| 51 | static DEFINE_PER_CPU(struct irqaction, timer_irq); |
| 52 | |
| 53 | static irqreturn_t timer_interrupt(int irq, void *dev_id) |
| 54 | { |
| 55 | struct clock_event_device *cd; |
| 56 | unsigned int cpu = smp_processor_id(); |
| 57 | |
| 58 | if (cpu == 0) |
| 59 | stop_jiffies_counter(); |
| 60 | else |
| 61 | stop_jiffies_counter1(); |
| 62 | |
| 63 | cd = &per_cpu(mn10300_clockevent_device, cpu); |
| 64 | cd->event_handler(cd); |
| 65 | |
| 66 | return IRQ_HANDLED; |
| 67 | } |
| 68 | |
| 69 | static void event_handler(struct clock_event_device *dev) |
| 70 | { |
| 71 | } |
| 72 | |
| 73 | int __init init_clockevents(void) |
| 74 | { |
| 75 | struct clock_event_device *cd; |
| 76 | struct irqaction *iact; |
| 77 | unsigned int cpu = smp_processor_id(); |
| 78 | |
| 79 | cd = &per_cpu(mn10300_clockevent_device, cpu); |
| 80 | |
| 81 | if (cpu == 0) { |
| 82 | stop_jiffies_counter(); |
| 83 | cd->irq = TMJCIRQ; |
| 84 | } else { |
| 85 | stop_jiffies_counter1(); |
| 86 | cd->irq = TMJC1IRQ; |
| 87 | } |
| 88 | |
| 89 | cd->name = "Timestamp"; |
| 90 | cd->features = CLOCK_EVT_FEAT_ONESHOT; |
| 91 | |
Thomas Gleixner | dc7daf3 | 2011-03-18 16:52:50 +0000 | [diff] [blame] | 92 | /* Calculate shift/mult. We want to spawn at least 1 second */ |
| 93 | clockevents_calc_mult_shift(cd, MN10300_JCCLK, 1); |
Mark Salter | 730c1fa | 2010-10-27 17:28:57 +0100 | [diff] [blame] | 94 | |
Thomas Gleixner | dc7daf3 | 2011-03-18 16:52:50 +0000 | [diff] [blame] | 95 | /* Calculate the min / max delta */ |
Mark Salter | 730c1fa | 2010-10-27 17:28:57 +0100 | [diff] [blame] | 96 | cd->max_delta_ns = clockevent_delta2ns(TMJCBR_MAX, cd); |
| 97 | cd->min_delta_ns = clockevent_delta2ns(100, cd); |
| 98 | |
| 99 | cd->rating = 200; |
| 100 | cd->cpumask = cpumask_of(smp_processor_id()); |
| 101 | cd->set_mode = set_clock_mode; |
| 102 | cd->event_handler = event_handler; |
| 103 | cd->set_next_event = next_event; |
| 104 | |
| 105 | iact = &per_cpu(timer_irq, cpu); |
| 106 | iact->flags = IRQF_DISABLED | IRQF_SHARED | IRQF_TIMER; |
| 107 | iact->handler = timer_interrupt; |
| 108 | |
| 109 | clockevents_register_device(cd); |
| 110 | |
| 111 | #if defined(CONFIG_SMP) && !defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) |
| 112 | /* setup timer irq affinity so it only runs on this cpu */ |
| 113 | { |
Thomas Gleixner | df43b86 | 2011-03-18 16:52:53 +0000 | [diff] [blame] | 114 | struct irq_data *data; |
| 115 | data = irq_get_irq_data(cd->irq); |
| 116 | cpumask_copy(data->affinity, cpumask_of(cpu)); |
Mark Salter | 730c1fa | 2010-10-27 17:28:57 +0100 | [diff] [blame] | 117 | iact->flags |= IRQF_NOBALANCING; |
| 118 | } |
| 119 | #endif |
| 120 | |
| 121 | if (cpu == 0) { |
| 122 | reload_jiffies_counter(MN10300_JC_PER_HZ - 1); |
| 123 | iact->name = "CPU0 Timer"; |
| 124 | } else { |
| 125 | reload_jiffies_counter1(MN10300_JC_PER_HZ - 1); |
| 126 | iact->name = "CPU1 Timer"; |
| 127 | } |
| 128 | |
| 129 | setup_jiffies_interrupt(cd->irq, iact); |
| 130 | |
| 131 | return 0; |
| 132 | } |