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 (file)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -575,6 +575,7 @@ config ARCH_W90X900
        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 (file)
--- 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 @@ static void __init nuc900_clockevents_init(void)
        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 @@ static void __init nuc900_clocksource_init(void)
        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)