Merge branch 'for-upstream' of git://openrisc.net/jonas/linux
[deliverable/linux.git] / arch / arm / mach-ux500 / timer.c
1 /*
2 * Copyright (C) ST-Ericsson SA 2011
3 *
4 * License Terms: GNU General Public License v2
5 * Author: Mattias Wallin <mattias.wallin@stericsson.com> for ST-Ericsson
6 */
7 #include <linux/io.h>
8 #include <linux/errno.h>
9 #include <linux/clksrc-dbx500-prcmu.h>
10 #include <linux/of.h>
11 #include <linux/of_address.h>
12 #include <linux/platform_data/clocksource-nomadik-mtu.h>
13
14 #include <asm/smp_twd.h>
15
16 #include <mach/setup.h>
17 #include <mach/hardware.h>
18 #include <mach/irqs.h>
19
20 #include "id.h"
21
22 #ifdef CONFIG_HAVE_ARM_TWD
23 static DEFINE_TWD_LOCAL_TIMER(u8500_twd_local_timer,
24 U8500_TWD_BASE, IRQ_LOCALTIMER);
25
26 static void __init ux500_twd_init(void)
27 {
28 struct twd_local_timer *twd_local_timer;
29 int err;
30
31 /* Use this to switch local timer base if changed in new ASICs */
32 twd_local_timer = &u8500_twd_local_timer;
33
34 if (of_have_populated_dt())
35 twd_local_timer_of_register();
36 else {
37 err = twd_local_timer_register(twd_local_timer);
38 if (err)
39 pr_err("twd_local_timer_register failed %d\n", err);
40 }
41 }
42 #else
43 #define ux500_twd_init() do { } while(0)
44 #endif
45
46 const static struct of_device_id prcmu_timer_of_match[] __initconst = {
47 { .compatible = "stericsson,db8500-prcmu-timer-4", },
48 { },
49 };
50
51 void __init ux500_timer_init(void)
52 {
53 void __iomem *mtu_timer_base;
54 void __iomem *prcmu_timer_base;
55 void __iomem *tmp_base;
56 struct device_node *np;
57
58 if (cpu_is_u8500_family() || cpu_is_ux540_family()) {
59 mtu_timer_base = __io_address(U8500_MTU0_BASE);
60 prcmu_timer_base = __io_address(U8500_PRCMU_TIMER_4_BASE);
61 } else {
62 ux500_unknown_soc();
63 }
64
65 /* TODO: Once MTU has been DT:ed place code above into else. */
66 if (of_have_populated_dt()) {
67 #ifdef CONFIG_OF
68 np = of_find_matching_node(NULL, prcmu_timer_of_match);
69 if (!np)
70 #endif
71 goto dt_fail;
72
73 tmp_base = of_iomap(np, 0);
74 if (!tmp_base)
75 goto dt_fail;
76
77 prcmu_timer_base = tmp_base;
78 }
79
80 dt_fail:
81 /* Doing it the old fashioned way. */
82
83 /*
84 * Here we register the timerblocks active in the system.
85 * Localtimers (twd) is started when both cpu is up and running.
86 * MTU register a clocksource, clockevent and sched_clock.
87 * Since the MTU is located in the VAPE power domain
88 * it will be cleared in sleep which makes it unsuitable.
89 * We however need it as a timer tick (clockevent)
90 * during boot to calibrate delay until twd is started.
91 * RTC-RTT have problems as timer tick during boot since it is
92 * depending on delay which is not yet calibrated. RTC-RTT is in the
93 * always-on powerdomain and is used as clockevent instead of twd when
94 * sleeping.
95 * The PRCMU timer 4 register a clocksource and
96 * sched_clock with higher rating then MTU since is always-on.
97 *
98 */
99
100 nmdk_timer_init(mtu_timer_base, IRQ_MTU0);
101 clksrc_dbx500_prcmu_init(prcmu_timer_base);
102 ux500_twd_init();
103 }
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