Commit b49c87c2 authored by Kevin Hilman's avatar Kevin Hilman Committed by Russell King
Browse files

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



Update Versatile to use new clocksource infrastructure for basic timekeeping.

Signed-off-by: default avatarKevin Hilman <khilman@mvista.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent e32f1502

arch/arm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -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.

arch/arm/mach-versatile/core.c

+34 −41
Original line number Diff line number Diff line
@@ -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,

};