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
15 #include <asm/mach/time.h>
16 #include <asm/sched_clock.h>
17
18 #include "common.h"
19
timer_get_base_and_rate(struct device_node * np,void __iomem ** base,u32 * rate)20 static void timer_get_base_and_rate(struct device_node *np,
21 void __iomem **base, u32 *rate)
22 {
23 *base = of_iomap(np, 0);
24
25 if (!*base)
26 panic("Unable to map regs for %s", np->name);
27
28 if (of_property_read_u32(np, "clock-freq", rate))
29 panic("No clock-freq property for %s", np->name);
30 }
31
picoxcell_add_clockevent(struct device_node * event_timer)32 static void picoxcell_add_clockevent(struct device_node *event_timer)
33 {
34 void __iomem *iobase;
35 struct dw_apb_clock_event_device *ced;
36 u32 irq, rate;
37
38 irq = irq_of_parse_and_map(event_timer, 0);
39 if (irq == NO_IRQ)
40 panic("No IRQ for clock event timer");
41
42 timer_get_base_and_rate(event_timer, &iobase, &rate);
43
44 ced = dw_apb_clockevent_init(0, event_timer->name, 300, iobase, irq,
45 rate);
46 if (!ced)
47 panic("Unable to initialise clockevent device");
48
49 dw_apb_clockevent_register(ced);
50 }
51
picoxcell_add_clocksource(struct device_node * source_timer)52 static void picoxcell_add_clocksource(struct device_node *source_timer)
53 {
54 void __iomem *iobase;
55 struct dw_apb_clocksource *cs;
56 u32 rate;
57
58 timer_get_base_and_rate(source_timer, &iobase, &rate);
59
60 cs = dw_apb_clocksource_init(300, source_timer->name, iobase, rate);
61 if (!cs)
62 panic("Unable to initialise clocksource device");
63
64 dw_apb_clocksource_start(cs);
65 dw_apb_clocksource_register(cs);
66 }
67
68 static void __iomem *sched_io_base;
69
picoxcell_read_sched_clock(void)70 static u32 picoxcell_read_sched_clock(void)
71 {
72 return __raw_readl(sched_io_base);
73 }
74
75 static const struct of_device_id picoxcell_rtc_ids[] __initconst = {
76 { .compatible = "picochip,pc3x2-rtc" },
77 { /* Sentinel */ },
78 };
79
picoxcell_init_sched_clock(void)80 static void picoxcell_init_sched_clock(void)
81 {
82 struct device_node *sched_timer;
83 u32 rate;
84
85 sched_timer = of_find_matching_node(NULL, picoxcell_rtc_ids);
86 if (!sched_timer)
87 panic("No RTC for sched clock to use");
88
89 timer_get_base_and_rate(sched_timer, &sched_io_base, &rate);
90 of_node_put(sched_timer);
91
92 setup_sched_clock(picoxcell_read_sched_clock, 32, rate);
93 }
94
95 static const struct of_device_id picoxcell_timer_ids[] __initconst = {
96 { .compatible = "picochip,pc3x2-timer" },
97 {},
98 };
99
picoxcell_timer_init(void)100 static void __init picoxcell_timer_init(void)
101 {
102 struct device_node *event_timer, *source_timer;
103
104 event_timer = of_find_matching_node(NULL, picoxcell_timer_ids);
105 if (!event_timer)
106 panic("No timer for clockevent");
107 picoxcell_add_clockevent(event_timer);
108
109 source_timer = of_find_matching_node(event_timer, picoxcell_timer_ids);
110 if (!source_timer)
111 panic("No timer for clocksource");
112 picoxcell_add_clocksource(source_timer);
113
114 of_node_put(source_timer);
115
116 picoxcell_init_sched_clock();
117 }
118
119 struct sys_timer picoxcell_timer = {
120 .init = picoxcell_timer_init,
121 };
122