2 * Copyright (C) ST-Ericsson SA 2011
4 * License Terms: GNU General Public License v2
5 * Author: Mattias Wallin <mattias.wallin@stericsson.com> for ST-Ericsson
8 #include <linux/errno.h>
9 #include <linux/clksrc-dbx500-prcmu.h>
10 #include <linux/clocksource.h>
12 #include <linux/of_address.h>
13 #include <linux/platform_data/clocksource-nomadik-mtu.h>
15 #include <asm/smp_twd.h>
20 #include "db8500-regs.h"
23 #ifdef CONFIG_HAVE_ARM_TWD
24 static DEFINE_TWD_LOCAL_TIMER(u8500_twd_local_timer,
25 U8500_TWD_BASE, IRQ_LOCALTIMER);
27 static void __init ux500_twd_init(void)
29 struct twd_local_timer *twd_local_timer;
32 /* Use this to switch local timer base if changed in new ASICs */
33 twd_local_timer = &u8500_twd_local_timer;
35 if (of_have_populated_dt())
36 clocksource_of_init();
38 err = twd_local_timer_register(twd_local_timer);
40 pr_err("twd_local_timer_register failed %d\n", err);
44 #define ux500_twd_init() do { } while(0)
47 const static struct of_device_id prcmu_timer_of_match[] __initconst = {
48 { .compatible = "stericsson,db8500-prcmu-timer-4", },
52 void __init ux500_timer_init(void)
54 void __iomem *mtu_timer_base;
55 void __iomem *prcmu_timer_base;
56 void __iomem *tmp_base;
57 struct device_node *np;
59 if (cpu_is_u8500_family() || cpu_is_ux540_family()) {
60 mtu_timer_base = __io_address(U8500_MTU0_BASE);
61 prcmu_timer_base = __io_address(U8500_PRCMU_TIMER_4_BASE);
66 /* TODO: Once MTU has been DT:ed place code above into else. */
67 if (of_have_populated_dt()) {
69 np = of_find_matching_node(NULL, prcmu_timer_of_match);
74 tmp_base = of_iomap(np, 0);
78 prcmu_timer_base = tmp_base;
82 /* Doing it the old fashioned way. */
85 * Here we register the timerblocks active in the system.
86 * Localtimers (twd) is started when both cpu is up and running.
87 * MTU register a clocksource, clockevent and sched_clock.
88 * Since the MTU is located in the VAPE power domain
89 * it will be cleared in sleep which makes it unsuitable.
90 * We however need it as a timer tick (clockevent)
91 * during boot to calibrate delay until twd is started.
92 * RTC-RTT have problems as timer tick during boot since it is
93 * depending on delay which is not yet calibrated. RTC-RTT is in the
94 * always-on powerdomain and is used as clockevent instead of twd when
96 * The PRCMU timer 4 register a clocksource and
97 * sched_clock with higher rating then MTU since is always-on.
101 nmdk_timer_init(mtu_timer_base, IRQ_MTU0);
102 clksrc_dbx500_prcmu_init(prcmu_timer_base);