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 | ||
fc6a6772 EG |
82 | static void gic_update_frequency(void *data) |
83 | { | |
84 | unsigned long rate = (unsigned long)data; | |
85 | ||
86 | clockevents_update_freq(this_cpu_ptr(&gic_clockevent_device), rate); | |
87 | } | |
88 | ||
e4752dbb AB |
89 | static int gic_cpu_notifier(struct notifier_block *nb, unsigned long action, |
90 | void *data) | |
91 | { | |
92 | switch (action & ~CPU_TASKS_FROZEN) { | |
93 | case CPU_STARTING: | |
94 | gic_clockevent_cpu_init(this_cpu_ptr(&gic_clockevent_device)); | |
95 | break; | |
96 | case CPU_DYING: | |
97 | gic_clockevent_cpu_exit(this_cpu_ptr(&gic_clockevent_device)); | |
98 | break; | |
a331ce63 AB |
99 | } |
100 | ||
e4752dbb AB |
101 | return NOTIFY_OK; |
102 | } | |
103 | ||
fc6a6772 EG |
104 | static int gic_clk_notifier(struct notifier_block *nb, unsigned long action, |
105 | void *data) | |
106 | { | |
107 | struct clk_notifier_data *cnd = data; | |
108 | ||
109 | if (action == POST_RATE_CHANGE) | |
110 | on_each_cpu(gic_update_frequency, (void *)cnd->new_rate, 1); | |
111 | ||
112 | return NOTIFY_OK; | |
113 | } | |
114 | ||
115 | ||
e4752dbb AB |
116 | static struct notifier_block gic_cpu_nb = { |
117 | .notifier_call = gic_cpu_notifier, | |
118 | }; | |
119 | ||
fc6a6772 EG |
120 | static struct notifier_block gic_clk_nb = { |
121 | .notifier_call = gic_clk_notifier, | |
122 | }; | |
123 | ||
e4752dbb AB |
124 | static int gic_clockevent_init(void) |
125 | { | |
f95ac855 EG |
126 | int ret; |
127 | ||
e4752dbb AB |
128 | if (!cpu_has_counter || !gic_frequency) |
129 | return -ENXIO; | |
130 | ||
f95ac855 EG |
131 | ret = setup_percpu_irq(gic_timer_irq, &gic_compare_irqaction); |
132 | if (ret < 0) | |
133 | return ret; | |
e4752dbb | 134 | |
f95ac855 EG |
135 | ret = register_cpu_notifier(&gic_cpu_nb); |
136 | if (ret < 0) | |
137 | pr_warn("GIC: Unable to register CPU notifier\n"); | |
e4752dbb AB |
138 | |
139 | gic_clockevent_cpu_init(this_cpu_ptr(&gic_clockevent_device)); | |
a331ce63 AB |
140 | |
141 | return 0; | |
142 | } | |
143 | ||
778eeb1b SH |
144 | static cycle_t gic_hpt_read(struct clocksource *cs) |
145 | { | |
dfa762e1 | 146 | return gic_read_count(); |
778eeb1b SH |
147 | } |
148 | ||
149 | static struct clocksource gic_clocksource = { | |
150 | .name = "GIC", | |
151 | .read = gic_hpt_read, | |
152 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, | |
153 | }; | |
154 | ||
e12aa828 | 155 | static void __init __gic_clocksource_init(void) |
778eeb1b | 156 | { |
f95ac855 EG |
157 | int ret; |
158 | ||
778eeb1b | 159 | /* Set clocksource mask. */ |
387904ff | 160 | gic_clocksource.mask = CLOCKSOURCE_MASK(gic_get_count_width()); |
778eeb1b SH |
161 | |
162 | /* Calculate a somewhat reasonable rating value. */ | |
e12aa828 | 163 | gic_clocksource.rating = 200 + gic_frequency / 10000000; |
778eeb1b | 164 | |
f95ac855 EG |
165 | ret = clocksource_register_hz(&gic_clocksource, gic_frequency); |
166 | if (ret < 0) | |
167 | pr_warn("GIC: Unable to register clocksource\n"); | |
778eeb1b | 168 | } |
e12aa828 AB |
169 | |
170 | void __init gic_clocksource_init(unsigned int frequency) | |
171 | { | |
172 | gic_frequency = frequency; | |
173 | gic_timer_irq = MIPS_GIC_IRQ_BASE + | |
174 | GIC_LOCAL_TO_HWIRQ(GIC_LOCAL_INT_COMPARE); | |
175 | ||
176 | __gic_clocksource_init(); | |
67d4e669 EG |
177 | gic_clockevent_init(); |
178 | ||
179 | /* And finally start the counter */ | |
180 | gic_start_count(); | |
e12aa828 AB |
181 | } |
182 | ||
183 | static void __init gic_clocksource_of_init(struct device_node *node) | |
184 | { | |
5b4e8453 | 185 | struct clk *clk; |
fc6a6772 | 186 | int ret; |
5b4e8453 | 187 | |
e12aa828 AB |
188 | if (WARN_ON(!gic_present || !node->parent || |
189 | !of_device_is_compatible(node->parent, "mti,gic"))) | |
190 | return; | |
191 | ||
5b4e8453 AB |
192 | clk = of_clk_get(node, 0); |
193 | if (!IS_ERR(clk)) { | |
eb811c73 EG |
194 | if (clk_prepare_enable(clk) < 0) { |
195 | pr_err("GIC failed to enable clock\n"); | |
196 | clk_put(clk); | |
197 | return; | |
198 | } | |
199 | ||
5b4e8453 | 200 | gic_frequency = clk_get_rate(clk); |
5b4e8453 AB |
201 | } else if (of_property_read_u32(node, "clock-frequency", |
202 | &gic_frequency)) { | |
e12aa828 AB |
203 | pr_err("GIC frequency not specified.\n"); |
204 | return; | |
205 | } | |
206 | gic_timer_irq = irq_of_parse_and_map(node, 0); | |
207 | if (!gic_timer_irq) { | |
208 | pr_err("GIC timer IRQ not specified.\n"); | |
209 | return; | |
210 | } | |
211 | ||
212 | __gic_clocksource_init(); | |
fc6a6772 EG |
213 | |
214 | ret = gic_clockevent_init(); | |
215 | if (!ret && !IS_ERR(clk)) { | |
216 | if (clk_notifier_register(clk, &gic_clk_nb) < 0) | |
217 | pr_warn("GIC: Unable to register clock notifier\n"); | |
218 | } | |
67d4e669 EG |
219 | |
220 | /* And finally start the counter */ | |
221 | gic_start_count(); | |
e12aa828 AB |
222 | } |
223 | CLOCKSOURCE_OF_DECLARE(mips_gic_timer, "mti,gic-timer", | |
224 | gic_clocksource_of_init); |