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Diffstat (limited to 'arch/mips/jz4740/time.c')
-rw-r--r-- | arch/mips/jz4740/time.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/arch/mips/jz4740/time.c b/arch/mips/jz4740/time.c new file mode 100644 index 000000000000..fe01678d94fd --- /dev/null +++ b/arch/mips/jz4740/time.c | |||
@@ -0,0 +1,144 @@ | |||
1 | /* | ||
2 | * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de> | ||
3 | * JZ4740 platform time support | ||
4 | * | ||
5 | * This program is free software; you can redistribute it and/or modify it | ||
6 | * under the terms of the GNU General Public License as published by the | ||
7 | * Free Software Foundation; either version 2 of the License, or (at your | ||
8 | * option) any later version. | ||
9 | * | ||
10 | * You should have received a copy of the GNU General Public License along | ||
11 | * with this program; if not, write to the Free Software Foundation, Inc., | ||
12 | * 675 Mass Ave, Cambridge, MA 02139, USA. | ||
13 | * | ||
14 | */ | ||
15 | |||
16 | #include <linux/interrupt.h> | ||
17 | #include <linux/kernel.h> | ||
18 | #include <linux/time.h> | ||
19 | |||
20 | #include <linux/clockchips.h> | ||
21 | |||
22 | #include <asm/mach-jz4740/irq.h> | ||
23 | #include <asm/time.h> | ||
24 | |||
25 | #include "clock.h" | ||
26 | #include "timer.h" | ||
27 | |||
28 | #define TIMER_CLOCKEVENT 0 | ||
29 | #define TIMER_CLOCKSOURCE 1 | ||
30 | |||
31 | static uint16_t jz4740_jiffies_per_tick; | ||
32 | |||
33 | static cycle_t jz4740_clocksource_read(struct clocksource *cs) | ||
34 | { | ||
35 | return jz4740_timer_get_count(TIMER_CLOCKSOURCE); | ||
36 | } | ||
37 | |||
38 | static struct clocksource jz4740_clocksource = { | ||
39 | .name = "jz4740-timer", | ||
40 | .rating = 200, | ||
41 | .read = jz4740_clocksource_read, | ||
42 | .mask = CLOCKSOURCE_MASK(16), | ||
43 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, | ||
44 | }; | ||
45 | |||
46 | static irqreturn_t jz4740_clockevent_irq(int irq, void *devid) | ||
47 | { | ||
48 | struct clock_event_device *cd = devid; | ||
49 | |||
50 | jz4740_timer_ack_full(TIMER_CLOCKEVENT); | ||
51 | |||
52 | if (cd->mode != CLOCK_EVT_MODE_PERIODIC) | ||
53 | jz4740_timer_disable(TIMER_CLOCKEVENT); | ||
54 | |||
55 | cd->event_handler(cd); | ||
56 | |||
57 | return IRQ_HANDLED; | ||
58 | } | ||
59 | |||
60 | static void jz4740_clockevent_set_mode(enum clock_event_mode mode, | ||
61 | struct clock_event_device *cd) | ||
62 | { | ||
63 | switch (mode) { | ||
64 | case CLOCK_EVT_MODE_PERIODIC: | ||
65 | jz4740_timer_set_count(TIMER_CLOCKEVENT, 0); | ||
66 | jz4740_timer_set_period(TIMER_CLOCKEVENT, jz4740_jiffies_per_tick); | ||
67 | case CLOCK_EVT_MODE_RESUME: | ||
68 | jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT); | ||
69 | jz4740_timer_enable(TIMER_CLOCKEVENT); | ||
70 | break; | ||
71 | case CLOCK_EVT_MODE_ONESHOT: | ||
72 | case CLOCK_EVT_MODE_SHUTDOWN: | ||
73 | jz4740_timer_disable(TIMER_CLOCKEVENT); | ||
74 | break; | ||
75 | default: | ||
76 | break; | ||
77 | } | ||
78 | } | ||
79 | |||
80 | static int jz4740_clockevent_set_next(unsigned long evt, | ||
81 | struct clock_event_device *cd) | ||
82 | { | ||
83 | jz4740_timer_set_count(TIMER_CLOCKEVENT, 0); | ||
84 | jz4740_timer_set_period(TIMER_CLOCKEVENT, evt); | ||
85 | jz4740_timer_enable(TIMER_CLOCKEVENT); | ||
86 | |||
87 | return 0; | ||
88 | } | ||
89 | |||
90 | static struct clock_event_device jz4740_clockevent = { | ||
91 | .name = "jz4740-timer", | ||
92 | .features = CLOCK_EVT_FEAT_PERIODIC, | ||
93 | .set_next_event = jz4740_clockevent_set_next, | ||
94 | .set_mode = jz4740_clockevent_set_mode, | ||
95 | .rating = 200, | ||
96 | .irq = JZ4740_IRQ_TCU0, | ||
97 | }; | ||
98 | |||
99 | static struct irqaction timer_irqaction = { | ||
100 | .handler = jz4740_clockevent_irq, | ||
101 | .flags = IRQF_PERCPU | IRQF_TIMER, | ||
102 | .name = "jz4740-timerirq", | ||
103 | .dev_id = &jz4740_clockevent, | ||
104 | }; | ||
105 | |||
106 | void __init plat_time_init(void) | ||
107 | { | ||
108 | int ret; | ||
109 | uint32_t clk_rate; | ||
110 | uint16_t ctrl; | ||
111 | |||
112 | jz4740_timer_init(); | ||
113 | |||
114 | clk_rate = jz4740_clock_bdata.ext_rate >> 4; | ||
115 | jz4740_jiffies_per_tick = DIV_ROUND_CLOSEST(clk_rate, HZ); | ||
116 | |||
117 | clockevent_set_clock(&jz4740_clockevent, clk_rate); | ||
118 | jz4740_clockevent.min_delta_ns = clockevent_delta2ns(100, &jz4740_clockevent); | ||
119 | jz4740_clockevent.max_delta_ns = clockevent_delta2ns(0xffff, &jz4740_clockevent); | ||
120 | jz4740_clockevent.cpumask = cpumask_of(0); | ||
121 | |||
122 | clockevents_register_device(&jz4740_clockevent); | ||
123 | |||
124 | clocksource_set_clock(&jz4740_clocksource, clk_rate); | ||
125 | ret = clocksource_register(&jz4740_clocksource); | ||
126 | |||
127 | if (ret) | ||
128 | printk(KERN_ERR "Failed to register clocksource: %d\n", ret); | ||
129 | |||
130 | setup_irq(JZ4740_IRQ_TCU0, &timer_irqaction); | ||
131 | |||
132 | ctrl = JZ_TIMER_CTRL_PRESCALE_16 | JZ_TIMER_CTRL_SRC_EXT; | ||
133 | |||
134 | jz4740_timer_set_ctrl(TIMER_CLOCKEVENT, ctrl); | ||
135 | jz4740_timer_set_ctrl(TIMER_CLOCKSOURCE, ctrl); | ||
136 | |||
137 | jz4740_timer_set_period(TIMER_CLOCKEVENT, jz4740_jiffies_per_tick); | ||
138 | jz4740_timer_irq_full_enable(TIMER_CLOCKEVENT); | ||
139 | |||
140 | jz4740_timer_set_period(TIMER_CLOCKSOURCE, 0xffff); | ||
141 | |||
142 | jz4740_timer_enable(TIMER_CLOCKEVENT); | ||
143 | jz4740_timer_enable(TIMER_CLOCKSOURCE); | ||
144 | } | ||