linux-stable-rt/arch/arm/mach-ux500/timer.c

69 lines
1.9 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 <asm/localtimer.h>
#include <plat/mtu.h>
#include <mach/setup.h>
#include <mach/hardware.h>
static void __init ux500_timer_init(void)
{
void __iomem *prcmu_timer_base;
if (cpu_is_u5500()) {
#ifdef CONFIG_LOCAL_TIMERS
twd_base = __io_address(U5500_TWD_BASE);
#endif
mtu_base = __io_address(U5500_MTU0_BASE);
prcmu_timer_base = __io_address(U5500_PRCMU_TIMER_3_BASE);
} else if (cpu_is_u8500()) {
#ifdef CONFIG_LOCAL_TIMERS
twd_base = __io_address(U8500_TWD_BASE);
#endif
mtu_base = __io_address(U8500_MTU0_BASE);
prcmu_timer_base = __io_address(U8500_PRCMU_TIMER_4_BASE);
} else {
ux500_unknown_soc();
}
/*
* 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(3 for DB5500) register a clocksource and
* sched_clock with higher rating then MTU since is always-on.
*
*/
nmdk_timer_init();
clksrc_dbx500_prcmu_init(prcmu_timer_base);
}
static void ux500_timer_reset(void)
{
nmdk_clkevt_reset();
nmdk_clksrc_reset();
}
struct sys_timer ux500_timer = {
.init = ux500_timer_init,
.resume = ux500_timer_reset,
};