[ARM] 4260/1: clocksource support for Versatile platform
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>
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@ -166,6 +166,7 @@ config ARCH_VERSATILE
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select ARM_AMBA
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select ARM_VIC
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select ICST307
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select GENERIC_TIME
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help
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This enables support for ARM Ltd Versatile board.
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@ -26,6 +26,7 @@
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#include <linux/interrupt.h>
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#include <linux/amba/bus.h>
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#include <linux/amba/clcd.h>
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#include <linux/clocksource.h>
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#include <asm/cnt32_to_63.h>
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#include <asm/system.h>
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@ -828,46 +829,6 @@ void __init versatile_init(void)
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#define TICKS2USECS(x) ((x) / TICKS_PER_uSEC)
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#endif
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/*
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* Returns number of ms since last clock interrupt. Note that interrupts
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* will have been disabled by do_gettimeoffset()
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*/
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static unsigned long versatile_gettimeoffset(void)
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{
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unsigned long ticks1, ticks2, status;
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/*
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* Get the current number of ticks. Note that there is a race
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* condition between us reading the timer and checking for
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* an interrupt. We get around this by ensuring that the
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* counter has not reloaded between our two reads.
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*/
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ticks2 = readl(TIMER0_VA_BASE + TIMER_VALUE) & 0xffff;
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do {
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ticks1 = ticks2;
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status = __raw_readl(VA_IC_BASE + VIC_RAW_STATUS);
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ticks2 = readl(TIMER0_VA_BASE + TIMER_VALUE) & 0xffff;
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} while (ticks2 > ticks1);
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/*
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* Number of ticks since last interrupt.
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*/
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ticks1 = TIMER_RELOAD - ticks2;
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/*
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* Interrupt pending? If so, we've reloaded once already.
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*
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* FIXME: Need to check this is effectively timer 0 that expires
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*/
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if (status & IRQMASK_TIMERINT0_1)
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ticks1 += TIMER_RELOAD;
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/*
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* Convert the ticks to usecs
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*/
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return TICKS2USECS(ticks1);
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}
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/*
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* IRQ handler for the timer
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*/
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@ -891,6 +852,36 @@ static struct irqaction versatile_timer_irq = {
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.handler = versatile_timer_interrupt,
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};
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static cycle_t versatile_get_cycles(void)
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{
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return ~readl(TIMER3_VA_BASE + TIMER_VALUE);
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}
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static struct clocksource clocksource_versatile = {
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.name = "timer3",
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.rating = 200,
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.read = versatile_get_cycles,
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.mask = CLOCKSOURCE_MASK(32),
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.shift = 20,
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.flags = CLOCK_SOURCE_IS_CONTINUOUS,
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};
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static int __init versatile_clocksource_init(void)
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{
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/* setup timer3 as free-running clocksource */
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writel(0, TIMER3_VA_BASE + TIMER_CTRL);
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writel(0xffffffff, TIMER3_VA_BASE + TIMER_LOAD);
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writel(0xffffffff, TIMER3_VA_BASE + TIMER_VALUE);
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writel(TIMER_CTRL_32BIT | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC,
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TIMER3_VA_BASE + TIMER_CTRL);
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clocksource_versatile.mult =
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clocksource_khz2mult(1000, clocksource_versatile.shift);
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clocksource_register(&clocksource_versatile);
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return 0;
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}
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/*
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* Set up timer interrupt, and return the current time in seconds.
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*/
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@ -927,9 +918,11 @@ static void __init versatile_timer_init(void)
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* Make irqs happen for the system timer
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*/
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setup_irq(IRQ_TIMERINT0_1, &versatile_timer_irq);
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versatile_clocksource_init();
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}
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struct sys_timer versatile_timer = {
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.init = versatile_timer_init,
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.offset = versatile_gettimeoffset,
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};
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