Steven J. Hill | 778eeb1 | 2012-12-07 03:51:04 +0000 | [diff] [blame] | 1 | /* |
| 2 | * This file is subject to the terms and conditions of the GNU General Public |
| 3 | * License. See the file "COPYING" in the main directory of this archive |
| 4 | * for more details. |
| 5 | * |
| 6 | * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved. |
| 7 | */ |
Andrew Bresticker | 5b4e845 | 2015-02-23 18:28:34 -0800 | [diff] [blame] | 8 | #include <linux/clk.h> |
Andrew Bresticker | a331ce6 | 2014-10-20 12:03:59 -0700 | [diff] [blame] | 9 | #include <linux/clockchips.h> |
Andrew Bresticker | e4752db | 2014-10-20 12:04:04 -0700 | [diff] [blame] | 10 | #include <linux/cpu.h> |
Steven J. Hill | 778eeb1 | 2012-12-07 03:51:04 +0000 | [diff] [blame] | 11 | #include <linux/init.h> |
Andrew Bresticker | a331ce6 | 2014-10-20 12:03:59 -0700 | [diff] [blame] | 12 | #include <linux/interrupt.h> |
Andrew Bresticker | 4060bbe | 2014-10-20 12:03:53 -0700 | [diff] [blame] | 13 | #include <linux/irqchip/mips-gic.h> |
Andrew Bresticker | e4752db | 2014-10-20 12:04:04 -0700 | [diff] [blame] | 14 | #include <linux/notifier.h> |
Andrew Bresticker | e12aa82 | 2014-11-12 11:43:39 -0800 | [diff] [blame] | 15 | #include <linux/of_irq.h> |
Andrew Bresticker | a331ce6 | 2014-10-20 12:03:59 -0700 | [diff] [blame] | 16 | #include <linux/percpu.h> |
| 17 | #include <linux/smp.h> |
Steven J. Hill | dfa762e | 2013-04-10 16:28:36 -0500 | [diff] [blame] | 18 | #include <linux/time.h> |
Steven J. Hill | 778eeb1 | 2012-12-07 03:51:04 +0000 | [diff] [blame] | 19 | |
Andrew Bresticker | 5fee56e | 2014-10-20 12:04:00 -0700 | [diff] [blame] | 20 | static DEFINE_PER_CPU(struct clock_event_device, gic_clockevent_device); |
Andrew Bresticker | e4752db | 2014-10-20 12:04:04 -0700 | [diff] [blame] | 21 | static int gic_timer_irq; |
Andrew Bresticker | b085451 | 2014-10-20 12:04:01 -0700 | [diff] [blame] | 22 | static unsigned int gic_frequency; |
Andrew Bresticker | a331ce6 | 2014-10-20 12:03:59 -0700 | [diff] [blame] | 23 | |
| 24 | static int gic_next_event(unsigned long delta, struct clock_event_device *evt) |
| 25 | { |
| 26 | u64 cnt; |
| 27 | int res; |
| 28 | |
| 29 | cnt = gic_read_count(); |
| 30 | cnt += (u64)delta; |
| 31 | gic_write_cpu_compare(cnt, cpumask_first(evt->cpumask)); |
| 32 | res = ((int)(gic_read_count() - cnt) >= 0) ? -ETIME : 0; |
| 33 | return res; |
| 34 | } |
| 35 | |
Andrew Bresticker | 5fee56e | 2014-10-20 12:04:00 -0700 | [diff] [blame] | 36 | static irqreturn_t gic_compare_interrupt(int irq, void *dev_id) |
Andrew Bresticker | a331ce6 | 2014-10-20 12:03:59 -0700 | [diff] [blame] | 37 | { |
Andrew Bresticker | f7ea306 | 2014-10-20 12:04:03 -0700 | [diff] [blame] | 38 | struct clock_event_device *cd = dev_id; |
Andrew Bresticker | a331ce6 | 2014-10-20 12:03:59 -0700 | [diff] [blame] | 39 | |
| 40 | gic_write_compare(gic_read_compare()); |
Andrew Bresticker | a331ce6 | 2014-10-20 12:03:59 -0700 | [diff] [blame] | 41 | cd->event_handler(cd); |
| 42 | return IRQ_HANDLED; |
| 43 | } |
| 44 | |
| 45 | struct irqaction gic_compare_irqaction = { |
| 46 | .handler = gic_compare_interrupt, |
Andrew Bresticker | f7ea306 | 2014-10-20 12:04:03 -0700 | [diff] [blame] | 47 | .percpu_dev_id = &gic_clockevent_device, |
Andrew Bresticker | a331ce6 | 2014-10-20 12:03:59 -0700 | [diff] [blame] | 48 | .flags = IRQF_PERCPU | IRQF_TIMER, |
| 49 | .name = "timer", |
| 50 | }; |
| 51 | |
Richard Cochran | 2dab909 | 2016-07-13 17:16:44 +0000 | [diff] [blame] | 52 | static void gic_clockevent_cpu_init(unsigned int cpu, |
| 53 | struct clock_event_device *cd) |
Andrew Bresticker | a331ce6 | 2014-10-20 12:03:59 -0700 | [diff] [blame] | 54 | { |
Andrew Bresticker | a331ce6 | 2014-10-20 12:03:59 -0700 | [diff] [blame] | 55 | cd->name = "MIPS GIC"; |
| 56 | cd->features = CLOCK_EVT_FEAT_ONESHOT | |
| 57 | CLOCK_EVT_FEAT_C3STOP; |
| 58 | |
Andrew Bresticker | a45da56 | 2014-10-20 12:04:06 -0700 | [diff] [blame] | 59 | cd->rating = 350; |
Andrew Bresticker | e4752db | 2014-10-20 12:04:04 -0700 | [diff] [blame] | 60 | cd->irq = gic_timer_irq; |
Andrew Bresticker | a331ce6 | 2014-10-20 12:03:59 -0700 | [diff] [blame] | 61 | cd->cpumask = cpumask_of(cpu); |
| 62 | cd->set_next_event = gic_next_event; |
Andrew Bresticker | a331ce6 | 2014-10-20 12:03:59 -0700 | [diff] [blame] | 63 | |
Andrew Bresticker | b695d8e | 2014-10-20 12:04:05 -0700 | [diff] [blame] | 64 | clockevents_config_and_register(cd, gic_frequency, 0x300, 0x7fffffff); |
Andrew Bresticker | a331ce6 | 2014-10-20 12:03:59 -0700 | [diff] [blame] | 65 | |
Andrew Bresticker | e4752db | 2014-10-20 12:04:04 -0700 | [diff] [blame] | 66 | enable_percpu_irq(gic_timer_irq, IRQ_TYPE_NONE); |
| 67 | } |
| 68 | |
| 69 | static void gic_clockevent_cpu_exit(struct clock_event_device *cd) |
| 70 | { |
| 71 | disable_percpu_irq(gic_timer_irq); |
| 72 | } |
| 73 | |
Ezequiel Garcia | fc6a677 | 2015-07-27 15:00:15 +0100 | [diff] [blame] | 74 | static void gic_update_frequency(void *data) |
| 75 | { |
| 76 | unsigned long rate = (unsigned long)data; |
| 77 | |
| 78 | clockevents_update_freq(this_cpu_ptr(&gic_clockevent_device), rate); |
| 79 | } |
| 80 | |
Richard Cochran | 2dab909 | 2016-07-13 17:16:44 +0000 | [diff] [blame] | 81 | static int gic_starting_cpu(unsigned int cpu) |
Andrew Bresticker | e4752db | 2014-10-20 12:04:04 -0700 | [diff] [blame] | 82 | { |
Richard Cochran | 2dab909 | 2016-07-13 17:16:44 +0000 | [diff] [blame] | 83 | gic_clockevent_cpu_init(cpu, this_cpu_ptr(&gic_clockevent_device)); |
| 84 | return 0; |
Andrew Bresticker | e4752db | 2014-10-20 12:04:04 -0700 | [diff] [blame] | 85 | } |
| 86 | |
Ezequiel Garcia | fc6a677 | 2015-07-27 15:00:15 +0100 | [diff] [blame] | 87 | static int gic_clk_notifier(struct notifier_block *nb, unsigned long action, |
| 88 | void *data) |
| 89 | { |
| 90 | struct clk_notifier_data *cnd = data; |
| 91 | |
| 92 | if (action == POST_RATE_CHANGE) |
| 93 | on_each_cpu(gic_update_frequency, (void *)cnd->new_rate, 1); |
| 94 | |
| 95 | return NOTIFY_OK; |
| 96 | } |
| 97 | |
Richard Cochran | 2dab909 | 2016-07-13 17:16:44 +0000 | [diff] [blame] | 98 | static int gic_dying_cpu(unsigned int cpu) |
| 99 | { |
| 100 | gic_clockevent_cpu_exit(this_cpu_ptr(&gic_clockevent_device)); |
| 101 | return 0; |
| 102 | } |
Andrew Bresticker | e4752db | 2014-10-20 12:04:04 -0700 | [diff] [blame] | 103 | |
Ezequiel Garcia | fc6a677 | 2015-07-27 15:00:15 +0100 | [diff] [blame] | 104 | static struct notifier_block gic_clk_nb = { |
| 105 | .notifier_call = gic_clk_notifier, |
| 106 | }; |
| 107 | |
Andrew Bresticker | e4752db | 2014-10-20 12:04:04 -0700 | [diff] [blame] | 108 | static int gic_clockevent_init(void) |
| 109 | { |
Ezequiel Garcia | f95ac85 | 2015-07-27 15:00:13 +0100 | [diff] [blame] | 110 | int ret; |
| 111 | |
Andrew Bresticker | e4752db | 2014-10-20 12:04:04 -0700 | [diff] [blame] | 112 | if (!cpu_has_counter || !gic_frequency) |
| 113 | return -ENXIO; |
| 114 | |
Ezequiel Garcia | f95ac85 | 2015-07-27 15:00:13 +0100 | [diff] [blame] | 115 | ret = setup_percpu_irq(gic_timer_irq, &gic_compare_irqaction); |
| 116 | if (ret < 0) |
| 117 | return ret; |
Andrew Bresticker | e4752db | 2014-10-20 12:04:04 -0700 | [diff] [blame] | 118 | |
Richard Cochran | 2dab909 | 2016-07-13 17:16:44 +0000 | [diff] [blame] | 119 | cpuhp_setup_state(CPUHP_AP_MIPS_GIC_TIMER_STARTING, |
| 120 | "AP_MIPS_GIC_TIMER_STARTING", gic_starting_cpu, |
| 121 | gic_dying_cpu); |
Andrew Bresticker | a331ce6 | 2014-10-20 12:03:59 -0700 | [diff] [blame] | 122 | return 0; |
| 123 | } |
| 124 | |
Steven J. Hill | 778eeb1 | 2012-12-07 03:51:04 +0000 | [diff] [blame] | 125 | static cycle_t gic_hpt_read(struct clocksource *cs) |
| 126 | { |
Steven J. Hill | dfa762e | 2013-04-10 16:28:36 -0500 | [diff] [blame] | 127 | return gic_read_count(); |
Steven J. Hill | 778eeb1 | 2012-12-07 03:51:04 +0000 | [diff] [blame] | 128 | } |
| 129 | |
| 130 | static struct clocksource gic_clocksource = { |
Alex Smith | a7f4df4 | 2015-10-21 09:57:44 +0100 | [diff] [blame] | 131 | .name = "GIC", |
| 132 | .read = gic_hpt_read, |
| 133 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
| 134 | .archdata = { .vdso_clock_mode = VDSO_CLOCK_GIC }, |
Steven J. Hill | 778eeb1 | 2012-12-07 03:51:04 +0000 | [diff] [blame] | 135 | }; |
| 136 | |
Daniel Lezcano | d8152bf | 2016-06-06 17:57:25 +0200 | [diff] [blame] | 137 | static int __init __gic_clocksource_init(void) |
Steven J. Hill | 778eeb1 | 2012-12-07 03:51:04 +0000 | [diff] [blame] | 138 | { |
Ezequiel Garcia | f95ac85 | 2015-07-27 15:00:13 +0100 | [diff] [blame] | 139 | int ret; |
| 140 | |
Steven J. Hill | 778eeb1 | 2012-12-07 03:51:04 +0000 | [diff] [blame] | 141 | /* Set clocksource mask. */ |
Andrew Bresticker | 387904f | 2014-10-20 12:03:49 -0700 | [diff] [blame] | 142 | gic_clocksource.mask = CLOCKSOURCE_MASK(gic_get_count_width()); |
Steven J. Hill | 778eeb1 | 2012-12-07 03:51:04 +0000 | [diff] [blame] | 143 | |
| 144 | /* Calculate a somewhat reasonable rating value. */ |
Andrew Bresticker | e12aa82 | 2014-11-12 11:43:39 -0800 | [diff] [blame] | 145 | gic_clocksource.rating = 200 + gic_frequency / 10000000; |
Steven J. Hill | 778eeb1 | 2012-12-07 03:51:04 +0000 | [diff] [blame] | 146 | |
Ezequiel Garcia | f95ac85 | 2015-07-27 15:00:13 +0100 | [diff] [blame] | 147 | ret = clocksource_register_hz(&gic_clocksource, gic_frequency); |
| 148 | if (ret < 0) |
| 149 | pr_warn("GIC: Unable to register clocksource\n"); |
Daniel Lezcano | d8152bf | 2016-06-06 17:57:25 +0200 | [diff] [blame] | 150 | |
| 151 | return ret; |
Steven J. Hill | 778eeb1 | 2012-12-07 03:51:04 +0000 | [diff] [blame] | 152 | } |
Andrew Bresticker | e12aa82 | 2014-11-12 11:43:39 -0800 | [diff] [blame] | 153 | |
| 154 | void __init gic_clocksource_init(unsigned int frequency) |
| 155 | { |
| 156 | gic_frequency = frequency; |
| 157 | gic_timer_irq = MIPS_GIC_IRQ_BASE + |
| 158 | GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_COMPARE); |
| 159 | |
| 160 | __gic_clocksource_init(); |
Ezequiel Garcia | 67d4e66 | 2015-07-27 15:00:14 +0100 | [diff] [blame] | 161 | gic_clockevent_init(); |
| 162 | |
| 163 | /* And finally start the counter */ |
| 164 | gic_start_count(); |
Andrew Bresticker | e12aa82 | 2014-11-12 11:43:39 -0800 | [diff] [blame] | 165 | } |
| 166 | |
Paul Gortmaker | be5769e | 2016-08-17 12:21:35 +0200 | [diff] [blame] | 167 | static int __init gic_clocksource_of_init(struct device_node *node) |
Andrew Bresticker | e12aa82 | 2014-11-12 11:43:39 -0800 | [diff] [blame] | 168 | { |
Andrew Bresticker | 5b4e845 | 2015-02-23 18:28:34 -0800 | [diff] [blame] | 169 | struct clk *clk; |
Ezequiel Garcia | fc6a677 | 2015-07-27 15:00:15 +0100 | [diff] [blame] | 170 | int ret; |
Andrew Bresticker | 5b4e845 | 2015-02-23 18:28:34 -0800 | [diff] [blame] | 171 | |
Daniel Lezcano | d8152bf | 2016-06-06 17:57:25 +0200 | [diff] [blame] | 172 | if (!gic_present || !node->parent || |
| 173 | !of_device_is_compatible(node->parent, "mti,gic")) { |
| 174 | pr_warn("No DT definition for the mips gic driver"); |
| 175 | return -ENXIO; |
| 176 | } |
Andrew Bresticker | e12aa82 | 2014-11-12 11:43:39 -0800 | [diff] [blame] | 177 | |
Andrew Bresticker | 5b4e845 | 2015-02-23 18:28:34 -0800 | [diff] [blame] | 178 | clk = of_clk_get(node, 0); |
| 179 | if (!IS_ERR(clk)) { |
Ezequiel Garcia | eb811c7 | 2015-07-27 15:00:12 +0100 | [diff] [blame] | 180 | if (clk_prepare_enable(clk) < 0) { |
| 181 | pr_err("GIC failed to enable clock\n"); |
| 182 | clk_put(clk); |
Daniel Lezcano | d8152bf | 2016-06-06 17:57:25 +0200 | [diff] [blame] | 183 | return PTR_ERR(clk); |
Ezequiel Garcia | eb811c7 | 2015-07-27 15:00:12 +0100 | [diff] [blame] | 184 | } |
| 185 | |
Andrew Bresticker | 5b4e845 | 2015-02-23 18:28:34 -0800 | [diff] [blame] | 186 | gic_frequency = clk_get_rate(clk); |
Andrew Bresticker | 5b4e845 | 2015-02-23 18:28:34 -0800 | [diff] [blame] | 187 | } else if (of_property_read_u32(node, "clock-frequency", |
| 188 | &gic_frequency)) { |
Andrew Bresticker | e12aa82 | 2014-11-12 11:43:39 -0800 | [diff] [blame] | 189 | pr_err("GIC frequency not specified.\n"); |
Daniel Lezcano | d8152bf | 2016-06-06 17:57:25 +0200 | [diff] [blame] | 190 | return -EINVAL;; |
Andrew Bresticker | e12aa82 | 2014-11-12 11:43:39 -0800 | [diff] [blame] | 191 | } |
| 192 | gic_timer_irq = irq_of_parse_and_map(node, 0); |
| 193 | if (!gic_timer_irq) { |
| 194 | pr_err("GIC timer IRQ not specified.\n"); |
Daniel Lezcano | d8152bf | 2016-06-06 17:57:25 +0200 | [diff] [blame] | 195 | return -EINVAL;; |
Andrew Bresticker | e12aa82 | 2014-11-12 11:43:39 -0800 | [diff] [blame] | 196 | } |
| 197 | |
Daniel Lezcano | d8152bf | 2016-06-06 17:57:25 +0200 | [diff] [blame] | 198 | ret = __gic_clocksource_init(); |
| 199 | if (ret) |
| 200 | return ret; |
Ezequiel Garcia | fc6a677 | 2015-07-27 15:00:15 +0100 | [diff] [blame] | 201 | |
| 202 | ret = gic_clockevent_init(); |
| 203 | if (!ret && !IS_ERR(clk)) { |
| 204 | if (clk_notifier_register(clk, &gic_clk_nb) < 0) |
| 205 | pr_warn("GIC: Unable to register clock notifier\n"); |
| 206 | } |
Ezequiel Garcia | 67d4e66 | 2015-07-27 15:00:14 +0100 | [diff] [blame] | 207 | |
| 208 | /* And finally start the counter */ |
| 209 | gic_start_count(); |
Daniel Lezcano | d8152bf | 2016-06-06 17:57:25 +0200 | [diff] [blame] | 210 | |
| 211 | return 0; |
Andrew Bresticker | e12aa82 | 2014-11-12 11:43:39 -0800 | [diff] [blame] | 212 | } |
Daniel Lezcano | 177cf6e | 2016-06-07 00:27:44 +0200 | [diff] [blame] | 213 | CLOCKSOURCE_OF_DECLARE(mips_gic_timer, "mti,gic-timer", |
Andrew Bresticker | e12aa82 | 2014-11-12 11:43:39 -0800 | [diff] [blame] | 214 | gic_clocksource_of_init); |