Commit | Line | Data |
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778eeb1b SH |
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 | */ | |
5b4e8453 | 8 | #include <linux/clk.h> |
a331ce63 | 9 | #include <linux/clockchips.h> |
e4752dbb | 10 | #include <linux/cpu.h> |
778eeb1b | 11 | #include <linux/init.h> |
a331ce63 | 12 | #include <linux/interrupt.h> |
4060bbe9 | 13 | #include <linux/irqchip/mips-gic.h> |
e4752dbb | 14 | #include <linux/notifier.h> |
e12aa828 | 15 | #include <linux/of_irq.h> |
a331ce63 AB |
16 | #include <linux/percpu.h> |
17 | #include <linux/smp.h> | |
dfa762e1 | 18 | #include <linux/time.h> |
778eeb1b | 19 | |
5fee56e0 | 20 | static DEFINE_PER_CPU(struct clock_event_device, gic_clockevent_device); |
e4752dbb | 21 | static int gic_timer_irq; |
b0854514 | 22 | static unsigned int gic_frequency; |
a331ce63 AB |
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 | ||
5fee56e0 | 36 | static void gic_set_clock_mode(enum clock_event_mode mode, |
a331ce63 AB |
37 | struct clock_event_device *evt) |
38 | { | |
39 | /* Nothing to do ... */ | |
40 | } | |
41 | ||
5fee56e0 | 42 | static irqreturn_t gic_compare_interrupt(int irq, void *dev_id) |
a331ce63 | 43 | { |
f7ea3060 | 44 | struct clock_event_device *cd = dev_id; |
a331ce63 AB |
45 | |
46 | gic_write_compare(gic_read_compare()); | |
a331ce63 AB |
47 | cd->event_handler(cd); |
48 | return IRQ_HANDLED; | |
49 | } | |
50 | ||
51 | struct irqaction gic_compare_irqaction = { | |
52 | .handler = gic_compare_interrupt, | |
f7ea3060 | 53 | .percpu_dev_id = &gic_clockevent_device, |
a331ce63 AB |
54 | .flags = IRQF_PERCPU | IRQF_TIMER, |
55 | .name = "timer", | |
56 | }; | |
57 | ||
e4752dbb | 58 | static void gic_clockevent_cpu_init(struct clock_event_device *cd) |
a331ce63 AB |
59 | { |
60 | unsigned int cpu = smp_processor_id(); | |
a331ce63 AB |
61 | |
62 | cd->name = "MIPS GIC"; | |
63 | cd->features = CLOCK_EVT_FEAT_ONESHOT | | |
64 | CLOCK_EVT_FEAT_C3STOP; | |
65 | ||
a45da565 | 66 | cd->rating = 350; |
e4752dbb | 67 | cd->irq = gic_timer_irq; |
a331ce63 AB |
68 | cd->cpumask = cpumask_of(cpu); |
69 | cd->set_next_event = gic_next_event; | |
70 | cd->set_mode = gic_set_clock_mode; | |
a331ce63 | 71 | |
b695d8e6 | 72 | clockevents_config_and_register(cd, gic_frequency, 0x300, 0x7fffffff); |
a331ce63 | 73 | |
e4752dbb AB |
74 | enable_percpu_irq(gic_timer_irq, IRQ_TYPE_NONE); |
75 | } | |
76 | ||
77 | static void gic_clockevent_cpu_exit(struct clock_event_device *cd) | |
78 | { | |
79 | disable_percpu_irq(gic_timer_irq); | |
80 | } | |
81 | ||
82 | static int gic_cpu_notifier(struct notifier_block *nb, unsigned long action, | |
83 | void *data) | |
84 | { | |
85 | switch (action & ~CPU_TASKS_FROZEN) { | |
86 | case CPU_STARTING: | |
87 | gic_clockevent_cpu_init(this_cpu_ptr(&gic_clockevent_device)); | |
88 | break; | |
89 | case CPU_DYING: | |
90 | gic_clockevent_cpu_exit(this_cpu_ptr(&gic_clockevent_device)); | |
91 | break; | |
a331ce63 AB |
92 | } |
93 | ||
e4752dbb AB |
94 | return NOTIFY_OK; |
95 | } | |
96 | ||
97 | static struct notifier_block gic_cpu_nb = { | |
98 | .notifier_call = gic_cpu_notifier, | |
99 | }; | |
100 | ||
101 | static int gic_clockevent_init(void) | |
102 | { | |
103 | if (!cpu_has_counter || !gic_frequency) | |
104 | return -ENXIO; | |
105 | ||
e4752dbb AB |
106 | setup_percpu_irq(gic_timer_irq, &gic_compare_irqaction); |
107 | ||
108 | register_cpu_notifier(&gic_cpu_nb); | |
109 | ||
110 | gic_clockevent_cpu_init(this_cpu_ptr(&gic_clockevent_device)); | |
a331ce63 AB |
111 | |
112 | return 0; | |
113 | } | |
114 | ||
778eeb1b SH |
115 | static cycle_t gic_hpt_read(struct clocksource *cs) |
116 | { | |
dfa762e1 | 117 | return gic_read_count(); |
778eeb1b SH |
118 | } |
119 | ||
120 | static struct clocksource gic_clocksource = { | |
121 | .name = "GIC", | |
122 | .read = gic_hpt_read, | |
123 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, | |
124 | }; | |
125 | ||
e12aa828 | 126 | static void __init __gic_clocksource_init(void) |
778eeb1b | 127 | { |
778eeb1b | 128 | /* Set clocksource mask. */ |
387904ff | 129 | gic_clocksource.mask = CLOCKSOURCE_MASK(gic_get_count_width()); |
778eeb1b SH |
130 | |
131 | /* Calculate a somewhat reasonable rating value. */ | |
e12aa828 | 132 | gic_clocksource.rating = 200 + gic_frequency / 10000000; |
778eeb1b | 133 | |
e12aa828 | 134 | clocksource_register_hz(&gic_clocksource, gic_frequency); |
e4752dbb AB |
135 | |
136 | gic_clockevent_init(); | |
7d9cd1f5 MC |
137 | |
138 | /* And finally start the counter */ | |
139 | gic_start_count(); | |
778eeb1b | 140 | } |
e12aa828 AB |
141 | |
142 | void __init gic_clocksource_init(unsigned int frequency) | |
143 | { | |
144 | gic_frequency = frequency; | |
145 | gic_timer_irq = MIPS_GIC_IRQ_BASE + | |
146 | GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_COMPARE); | |
147 | ||
148 | __gic_clocksource_init(); | |
149 | } | |
150 | ||
151 | static void __init gic_clocksource_of_init(struct device_node *node) | |
152 | { | |
5b4e8453 AB |
153 | struct clk *clk; |
154 | ||
e12aa828 AB |
155 | if (WARN_ON(!gic_present || !node->parent || |
156 | !of_device_is_compatible(node->parent, "mti,gic"))) | |
157 | return; | |
158 | ||
5b4e8453 AB |
159 | clk = of_clk_get(node, 0); |
160 | if (!IS_ERR(clk)) { | |
161 | gic_frequency = clk_get_rate(clk); | |
162 | clk_put(clk); | |
163 | } else if (of_property_read_u32(node, "clock-frequency", | |
164 | &gic_frequency)) { | |
e12aa828 AB |
165 | pr_err("GIC frequency not specified.\n"); |
166 | return; | |
167 | } | |
168 | gic_timer_irq = irq_of_parse_and_map(node, 0); | |
169 | if (!gic_timer_irq) { | |
170 | pr_err("GIC timer IRQ not specified.\n"); | |
171 | return; | |
172 | } | |
173 | ||
174 | __gic_clocksource_init(); | |
175 | } | |
176 | CLOCKSOURCE_OF_DECLARE(mips_gic_timer, "mti,gic-timer", | |
177 | gic_clocksource_of_init); |