[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>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 2aadd0e..cddd054 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -166,6 +166,7 @@
select ARM_AMBA
select ARM_VIC
select ICST307
+ select GENERIC_TIME
help
This enables support for ARM Ltd Versatile board.
diff --git a/arch/arm/mach-versatile/core.c b/arch/arm/mach-versatile/core.c
index bf71507c..08a9fe6 100644
--- a/arch/arm/mach-versatile/core.c
+++ b/arch/arm/mach-versatile/core.c
@@ -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>
@@ -829,46 +830,6 @@
#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
*/
static irqreturn_t versatile_timer_interrupt(int irq, void *dev_id)
@@ -891,6 +852,36 @@
.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 @@
* 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,
};
+