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 irqreturn_t gic_compare_interrupt(int irq, void *dev_id) |
a331ce63 | 37 | { |
f7ea3060 | 38 | struct clock_event_device *cd = dev_id; |
a331ce63 AB |
39 | |
40 | gic_write_compare(gic_read_compare()); | |
a331ce63 AB |
41 | cd->event_handler(cd); |
42 | return IRQ_HANDLED; | |
43 | } | |
44 | ||
45 | struct irqaction gic_compare_irqaction = { | |
46 | .handler = gic_compare_interrupt, | |
f7ea3060 | 47 | .percpu_dev_id = &gic_clockevent_device, |
a331ce63 AB |
48 | .flags = IRQF_PERCPU | IRQF_TIMER, |
49 | .name = "timer", | |
50 | }; | |
51 | ||
e4752dbb | 52 | static void gic_clockevent_cpu_init(struct clock_event_device *cd) |
a331ce63 AB |
53 | { |
54 | unsigned int cpu = smp_processor_id(); | |
a331ce63 AB |
55 | |
56 | cd->name = "MIPS GIC"; | |
57 | cd->features = CLOCK_EVT_FEAT_ONESHOT | | |
58 | CLOCK_EVT_FEAT_C3STOP; | |
59 | ||
a45da565 | 60 | cd->rating = 350; |
e4752dbb | 61 | cd->irq = gic_timer_irq; |
a331ce63 AB |
62 | cd->cpumask = cpumask_of(cpu); |
63 | cd->set_next_event = gic_next_event; | |
a331ce63 | 64 | |
b695d8e6 | 65 | clockevents_config_and_register(cd, gic_frequency, 0x300, 0x7fffffff); |
a331ce63 | 66 | |
e4752dbb AB |
67 | enable_percpu_irq(gic_timer_irq, IRQ_TYPE_NONE); |
68 | } | |
69 | ||
70 | static void gic_clockevent_cpu_exit(struct clock_event_device *cd) | |
71 | { | |
72 | disable_percpu_irq(gic_timer_irq); | |
73 | } | |
74 | ||
fc6a6772 EG |
75 | static void gic_update_frequency(void *data) |
76 | { | |
77 | unsigned long rate = (unsigned long)data; | |
78 | ||
79 | clockevents_update_freq(this_cpu_ptr(&gic_clockevent_device), rate); | |
80 | } | |
81 | ||
e4752dbb AB |
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 | ||
fc6a6772 EG |
97 | static int gic_clk_notifier(struct notifier_block *nb, unsigned long action, |
98 | void *data) | |
99 | { | |
100 | struct clk_notifier_data *cnd = data; | |
101 | ||
102 | if (action == POST_RATE_CHANGE) | |
103 | on_each_cpu(gic_update_frequency, (void *)cnd->new_rate, 1); | |
104 | ||
105 | return NOTIFY_OK; | |
106 | } | |
107 | ||
108 | ||
e4752dbb AB |
109 | static struct notifier_block gic_cpu_nb = { |
110 | .notifier_call = gic_cpu_notifier, | |
111 | }; | |
112 | ||
fc6a6772 EG |
113 | static struct notifier_block gic_clk_nb = { |
114 | .notifier_call = gic_clk_notifier, | |
115 | }; | |
116 | ||
e4752dbb AB |
117 | static int gic_clockevent_init(void) |
118 | { | |
f95ac855 EG |
119 | int ret; |
120 | ||
e4752dbb AB |
121 | if (!cpu_has_counter || !gic_frequency) |
122 | return -ENXIO; | |
123 | ||
f95ac855 EG |
124 | ret = setup_percpu_irq(gic_timer_irq, &gic_compare_irqaction); |
125 | if (ret < 0) | |
126 | return ret; | |
e4752dbb | 127 | |
f95ac855 EG |
128 | ret = register_cpu_notifier(&gic_cpu_nb); |
129 | if (ret < 0) | |
130 | pr_warn("GIC: Unable to register CPU notifier\n"); | |
e4752dbb AB |
131 | |
132 | gic_clockevent_cpu_init(this_cpu_ptr(&gic_clockevent_device)); | |
a331ce63 AB |
133 | |
134 | return 0; | |
135 | } | |
136 | ||
778eeb1b SH |
137 | static cycle_t gic_hpt_read(struct clocksource *cs) |
138 | { | |
dfa762e1 | 139 | return gic_read_count(); |
778eeb1b SH |
140 | } |
141 | ||
142 | static struct clocksource gic_clocksource = { | |
a7f4df4e AS |
143 | .name = "GIC", |
144 | .read = gic_hpt_read, | |
145 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, | |
146 | .archdata = { .vdso_clock_mode = VDSO_CLOCK_GIC }, | |
778eeb1b SH |
147 | }; |
148 | ||
e12aa828 | 149 | static void __init __gic_clocksource_init(void) |
778eeb1b | 150 | { |
f95ac855 EG |
151 | int ret; |
152 | ||
778eeb1b | 153 | /* Set clocksource mask. */ |
387904ff | 154 | gic_clocksource.mask = CLOCKSOURCE_MASK(gic_get_count_width()); |
778eeb1b SH |
155 | |
156 | /* Calculate a somewhat reasonable rating value. */ | |
e12aa828 | 157 | gic_clocksource.rating = 200 + gic_frequency / 10000000; |
778eeb1b | 158 | |
f95ac855 EG |
159 | ret = clocksource_register_hz(&gic_clocksource, gic_frequency); |
160 | if (ret < 0) | |
161 | pr_warn("GIC: Unable to register clocksource\n"); | |
778eeb1b | 162 | } |
e12aa828 AB |
163 | |
164 | void __init gic_clocksource_init(unsigned int frequency) | |
165 | { | |
166 | gic_frequency = frequency; | |
167 | gic_timer_irq = MIPS_GIC_IRQ_BASE + | |
168 | GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_COMPARE); | |
169 | ||
170 | __gic_clocksource_init(); | |
67d4e669 EG |
171 | gic_clockevent_init(); |
172 | ||
173 | /* And finally start the counter */ | |
174 | gic_start_count(); | |
e12aa828 AB |
175 | } |
176 | ||
177 | static void __init gic_clocksource_of_init(struct device_node *node) | |
178 | { | |
5b4e8453 | 179 | struct clk *clk; |
fc6a6772 | 180 | int ret; |
5b4e8453 | 181 | |
e12aa828 AB |
182 | if (WARN_ON(!gic_present || !node->parent || |
183 | !of_device_is_compatible(node->parent, "mti,gic"))) | |
184 | return; | |
185 | ||
5b4e8453 AB |
186 | clk = of_clk_get(node, 0); |
187 | if (!IS_ERR(clk)) { | |
eb811c73 EG |
188 | if (clk_prepare_enable(clk) < 0) { |
189 | pr_err("GIC failed to enable clock\n"); | |
190 | clk_put(clk); | |
191 | return; | |
192 | } | |
193 | ||
5b4e8453 | 194 | gic_frequency = clk_get_rate(clk); |
5b4e8453 AB |
195 | } else if (of_property_read_u32(node, "clock-frequency", |
196 | &gic_frequency)) { | |
e12aa828 AB |
197 | pr_err("GIC frequency not specified.\n"); |
198 | return; | |
199 | } | |
200 | gic_timer_irq = irq_of_parse_and_map(node, 0); | |
201 | if (!gic_timer_irq) { | |
202 | pr_err("GIC timer IRQ not specified.\n"); | |
203 | return; | |
204 | } | |
205 | ||
206 | __gic_clocksource_init(); | |
fc6a6772 EG |
207 | |
208 | ret = gic_clockevent_init(); | |
209 | if (!ret && !IS_ERR(clk)) { | |
210 | if (clk_notifier_register(clk, &gic_clk_nb) < 0) | |
211 | pr_warn("GIC: Unable to register clock notifier\n"); | |
212 | } | |
67d4e669 EG |
213 | |
214 | /* And finally start the counter */ | |
215 | gic_start_count(); | |
e12aa828 AB |
216 | } |
217 | CLOCKSOURCE_OF_DECLARE(mips_gic_timer, "mti,gic-timer", | |
218 | gic_clocksource_of_init); |