clocksource: convert W90x900 24-bit down counting clocksource
Convert the W90x900 24-bit down-counting clocksource to the generic
mmio clocksource infrastructure
Acked-by: Wan ZongShun <mcuos.com@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 0a05a57..bab25a0 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -575,6 +575,7 @@
select CPU_ARM926T
select ARCH_REQUIRE_GPIOLIB
select CLKDEV_LOOKUP
+ select CLKSRC_MMIO
select GENERIC_CLOCKEVENTS
help
Support for Nuvoton (Winbond logic dept.) ARM9 processor,
diff --git a/arch/arm/mach-w90x900/time.c b/arch/arm/mach-w90x900/time.c
index 4b089cb..a2c4e2d 100644
--- a/arch/arm/mach-w90x900/time.c
+++ b/arch/arm/mach-w90x900/time.c
@@ -43,7 +43,6 @@
#define PRESCALE 0x63 /* Divider = prescale + 1 */
#define TDR_SHIFT 24
-#define TDR_MASK ((1 << TDR_SHIFT) - 1)
static unsigned int timer0_load;
@@ -143,19 +142,6 @@
clockevents_register_device(&nuc900_clockevent_device);
}
-static cycle_t nuc900_get_cycles(struct clocksource *cs)
-{
- return (~__raw_readl(REG_TDR1)) & TDR_MASK;
-}
-
-static struct clocksource clocksource_nuc900 = {
- .name = "nuc900-timer1",
- .rating = 200,
- .read = nuc900_get_cycles,
- .mask = CLOCKSOURCE_MASK(TDR_SHIFT),
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-
static void __init nuc900_clocksource_init(void)
{
unsigned int val;
@@ -175,7 +161,8 @@
val |= (COUNTEN | PERIOD | PRESCALE);
__raw_writel(val, REG_TCSR1);
- clocksource_register_hz(&clocksource_nuc900, rate);
+ clocksource_mmio_init(REG_TDR1, "nuc900-timer1", rate, 200,
+ TDR_SHIFT, clocksource_mmio_readl_down);
}
static void __init nuc900_timer_init(void)