OpenCloudOS-Kernel/arch/arm/mach-ux500/timer.c

105 lines
2.7 KiB
C

/*
* Copyright (C) ST-Ericsson SA 2011
*
* License Terms: GNU General Public License v2
* Author: Mattias Wallin <mattias.wallin@stericsson.com> for ST-Ericsson
*/
#include <linux/io.h>
#include <linux/errno.h>
#include <linux/clksrc-dbx500-prcmu.h>
#include <linux/clocksource.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_data/clocksource-nomadik-mtu.h>
#include <asm/smp_twd.h>
#include "setup.h"
#include "irqs.h"
#include "db8500-regs.h"
#include "id.h"
#ifdef CONFIG_HAVE_ARM_TWD
static DEFINE_TWD_LOCAL_TIMER(u8500_twd_local_timer,
U8500_TWD_BASE, IRQ_LOCALTIMER);
static void __init ux500_twd_init(void)
{
struct twd_local_timer *twd_local_timer;
int err;
/* Use this to switch local timer base if changed in new ASICs */
twd_local_timer = &u8500_twd_local_timer;
if (of_have_populated_dt())
clocksource_of_init();
else {
err = twd_local_timer_register(twd_local_timer);
if (err)
pr_err("twd_local_timer_register failed %d\n", err);
}
}
#else
#define ux500_twd_init() do { } while(0)
#endif
const static struct of_device_id prcmu_timer_of_match[] __initconst = {
{ .compatible = "stericsson,db8500-prcmu-timer-4", },
{ },
};
void __init ux500_timer_init(void)
{
void __iomem *mtu_timer_base;
void __iomem *prcmu_timer_base;
void __iomem *tmp_base;
struct device_node *np;
if (cpu_is_u8500_family() || cpu_is_ux540_family()) {
mtu_timer_base = __io_address(U8500_MTU0_BASE);
prcmu_timer_base = __io_address(U8500_PRCMU_TIMER_4_BASE);
} else {
ux500_unknown_soc();
}
/* TODO: Once MTU has been DT:ed place code above into else. */
if (of_have_populated_dt()) {
#ifdef CONFIG_OF
np = of_find_matching_node(NULL, prcmu_timer_of_match);
if (!np)
#endif
goto dt_fail;
tmp_base = of_iomap(np, 0);
if (!tmp_base)
goto dt_fail;
prcmu_timer_base = tmp_base;
}
dt_fail:
/* Doing it the old fashioned way. */
/*
* Here we register the timerblocks active in the system.
* Localtimers (twd) is started when both cpu is up and running.
* MTU register a clocksource, clockevent and sched_clock.
* Since the MTU is located in the VAPE power domain
* it will be cleared in sleep which makes it unsuitable.
* We however need it as a timer tick (clockevent)
* during boot to calibrate delay until twd is started.
* RTC-RTT have problems as timer tick during boot since it is
* depending on delay which is not yet calibrated. RTC-RTT is in the
* always-on powerdomain and is used as clockevent instead of twd when
* sleeping.
* The PRCMU timer 4 register a clocksource and
* sched_clock with higher rating then MTU since is always-on.
*
*/
if (!of_have_populated_dt())
nmdk_timer_init(mtu_timer_base, IRQ_MTU0);
clksrc_dbx500_prcmu_init(prcmu_timer_base);
ux500_twd_init();
}