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-rw-r--r--arch/arm/mach-picoxcell/time.c132
1 files changed, 132 insertions, 0 deletions
diff --git a/arch/arm/mach-picoxcell/time.c b/arch/arm/mach-picoxcell/time.c
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1/*
2 * Copyright (c) 2011 Picochip Ltd., Jamie Iles
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * All enquiries to support@picochip.com
9 */
10#include <linux/dw_apb_timer.h>
11#include <linux/of.h>
12#include <linux/of_address.h>
13#include <linux/of_irq.h>
14#include <linux/sched.h>
15
16#include <asm/mach/time.h>
17#include <asm/sched_clock.h>
18
19#include "common.h"
20
21static void timer_get_base_and_rate(struct device_node *np,
22 void __iomem **base, u32 *rate)
23{
24 *base = of_iomap(np, 0);
25
26 if (!*base)
27 panic("Unable to map regs for %s", np->name);
28
29 if (of_property_read_u32(np, "clock-freq", rate))
30 panic("No clock-freq property for %s", np->name);
31}
32
33static void picoxcell_add_clockevent(struct device_node *event_timer)
34{
35 void __iomem *iobase;
36 struct dw_apb_clock_event_device *ced;
37 u32 irq, rate;
38
39 irq = irq_of_parse_and_map(event_timer, 0);
40 if (irq == NO_IRQ)
41 panic("No IRQ for clock event timer");
42
43 timer_get_base_and_rate(event_timer, &iobase, &rate);
44
45 ced = dw_apb_clockevent_init(0, event_timer->name, 300, iobase, irq,
46 rate);
47 if (!ced)
48 panic("Unable to initialise clockevent device");
49
50 dw_apb_clockevent_register(ced);
51}
52
53static void picoxcell_add_clocksource(struct device_node *source_timer)
54{
55 void __iomem *iobase;
56 struct dw_apb_clocksource *cs;
57 u32 rate;
58
59 timer_get_base_and_rate(source_timer, &iobase, &rate);
60
61 cs = dw_apb_clocksource_init(300, source_timer->name, iobase, rate);
62 if (!cs)
63 panic("Unable to initialise clocksource device");
64
65 dw_apb_clocksource_start(cs);
66 dw_apb_clocksource_register(cs);
67}
68
69static DEFINE_CLOCK_DATA(cd);
70static void __iomem *sched_io_base;
71
72unsigned long long notrace sched_clock(void)
73{
74 cycle_t cyc = sched_io_base ? __raw_readl(sched_io_base) : 0;
75
76 return cyc_to_sched_clock(&cd, cyc, (u32)~0);
77}
78
79static void notrace picoxcell_update_sched_clock(void)
80{
81 cycle_t cyc = sched_io_base ? __raw_readl(sched_io_base) : 0;
82
83 update_sched_clock(&cd, cyc, (u32)~0);
84}
85
86static const struct of_device_id picoxcell_rtc_ids[] __initconst = {
87 { .compatible = "picochip,pc3x2-rtc" },
88 { /* Sentinel */ },
89};
90
91static void picoxcell_init_sched_clock(void)
92{
93 struct device_node *sched_timer;
94 u32 rate;
95
96 sched_timer = of_find_matching_node(NULL, picoxcell_rtc_ids);
97 if (!sched_timer)
98 panic("No RTC for sched clock to use");
99
100 timer_get_base_and_rate(sched_timer, &sched_io_base, &rate);
101 of_node_put(sched_timer);
102
103 init_sched_clock(&cd, picoxcell_update_sched_clock, 32, rate);
104}
105
106static const struct of_device_id picoxcell_timer_ids[] __initconst = {
107 { .compatible = "picochip,pc3x2-timer" },
108 {},
109};
110
111static void __init picoxcell_timer_init(void)
112{
113 struct device_node *event_timer, *source_timer;
114
115 event_timer = of_find_matching_node(NULL, picoxcell_timer_ids);
116 if (!event_timer)
117 panic("No timer for clockevent");
118 picoxcell_add_clockevent(event_timer);
119
120 source_timer = of_find_matching_node(event_timer, picoxcell_timer_ids);
121 if (!source_timer)
122 panic("No timer for clocksource");
123 picoxcell_add_clocksource(source_timer);
124
125 of_node_put(source_timer);
126
127 picoxcell_init_sched_clock();
128}
129
130struct sys_timer picoxcell_timer = {
131 .init = picoxcell_timer_init,
132};