Commit 6fa5d5f7 authored by Russell King's avatar Russell King
Browse files

clocksource: convert W90x900 24-bit down counting clocksource 



Convert the W90x900 24-bit down-counting clocksource to the generic
mmio clocksource infrastructure

Acked-by: default avatarWan ZongShun <mcuos.com@gmail.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent bfe45e0b

arch/arm/Kconfig

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

arch/arm/mach-w90x900/time.c

+2 −15
Original line number Diff line number Diff line
@@ -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)