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af75655c JI |
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 | ||
21 | static 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 | ||
33 | static 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 | ||
53 | static 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 | ||
69 | static DEFINE_CLOCK_DATA(cd); | |
70 | static void __iomem *sched_io_base; | |
71 | ||
72 | unsigned 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 | ||
79 | static 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 | ||
86 | static const struct of_device_id picoxcell_rtc_ids[] __initconst = { | |
87 | { .compatible = "picochip,pc3x2-rtc" }, | |
88 | { /* Sentinel */ }, | |
89 | }; | |
90 | ||
91 | static 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 | ||
106 | static const struct of_device_id picoxcell_timer_ids[] __initconst = { | |
107 | { .compatible = "picochip,pc3x2-timer" }, | |
108 | {}, | |
109 | }; | |
110 | ||
111 | static 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 | ||
130 | struct sys_timer picoxcell_timer = { | |
131 | .init = picoxcell_timer_init, | |
132 | }; |