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[ARM] 4260/1: clocksource support for Versatile platform

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Update Versatile to use new clocksource infrastructure for basic timekeeping.

Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Kevin Hilman 2007-03-08 20:25:13 +01:00 committed by Russell King
parent e32f1502be
commit b49c87c2a5
2 changed files with 35 additions and 41 deletions
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1
arch/arm/Kconfig
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@ -166,6 +166,7 @@ config ARCH_VERSATILE
select ARM_AMBA
select ARM_VIC
select ICST307
select GENERIC_TIME
help
This enables support for ARM Ltd Versatile board.

75
arch/arm/mach-versatile/core.c
View file

@ -26,6 +26,7 @@
#include <linux/interrupt.h>
#include <linux/amba/bus.h>
#include <linux/amba/clcd.h>
#include <linux/clocksource.h>
#include <asm/cnt32_to_63.h>
#include <asm/system.h>
@ -828,46 +829,6 @@ void __init versatile_init(void)
#define TICKS2USECS(x) ((x) / TICKS_PER_uSEC)
#endif
/*
* Returns number of ms since last clock interrupt. Note that interrupts
* will have been disabled by do_gettimeoffset()
*/
static unsigned long versatile_gettimeoffset(void)
{
unsigned long ticks1, ticks2, status;
/*
* Get the current number of ticks. Note that there is a race
* condition between us reading the timer and checking for
* an interrupt. We get around this by ensuring that the
* counter has not reloaded between our two reads.
*/
ticks2 = readl(TIMER0_VA_BASE + TIMER_VALUE) & 0xffff;
do {
ticks1 = ticks2;
status = __raw_readl(VA_IC_BASE + VIC_RAW_STATUS);
ticks2 = readl(TIMER0_VA_BASE + TIMER_VALUE) & 0xffff;
} while (ticks2 > ticks1);
/*
* Number of ticks since last interrupt.
*/
ticks1 = TIMER_RELOAD - ticks2;
/*
* Interrupt pending? If so, we've reloaded once already.
*
* FIXME: Need to check this is effectively timer 0 that expires
*/
if (status & IRQMASK_TIMERINT0_1)
ticks1 += TIMER_RELOAD;
/*
* Convert the ticks to usecs
*/
return TICKS2USECS(ticks1);
}
/*
* IRQ handler for the timer
*/
@ -891,6 +852,36 @@ static struct irqaction versatile_timer_irq = {
.handler = versatile_timer_interrupt,
};
static cycle_t versatile_get_cycles(void)
{
return ~readl(TIMER3_VA_BASE + TIMER_VALUE);
}
static struct clocksource clocksource_versatile = {
.name = "timer3",
.rating = 200,
.read = versatile_get_cycles,
.mask = CLOCKSOURCE_MASK(32),
.shift = 20,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static int __init versatile_clocksource_init(void)
{
/* setup timer3 as free-running clocksource */
writel(0, TIMER3_VA_BASE + TIMER_CTRL);
writel(0xffffffff, TIMER3_VA_BASE + TIMER_LOAD);
writel(0xffffffff, TIMER3_VA_BASE + TIMER_VALUE);
writel(TIMER_CTRL_32BIT | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC,
TIMER3_VA_BASE + TIMER_CTRL);
clocksource_versatile.mult =
clocksource_khz2mult(1000, clocksource_versatile.shift);
clocksource_register(&clocksource_versatile);
return 0;
}
/*
* Set up timer interrupt, and return the current time in seconds.
*/
@ -927,9 +918,11 @@ static void __init versatile_timer_init(void)
* Make irqs happen for the system timer
*/
setup_irq(IRQ_TIMERINT0_1, &versatile_timer_irq);
versatile_clocksource_init();
}
struct sys_timer versatile_timer = {
.init = versatile_timer_init,
.offset = versatile_gettimeoffset,
};