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author | Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de> | 2007-09-30 19:35:48 (GMT) |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2007-10-12 22:43:37 (GMT) |
commit | cef5975d453bbc1bbf29ceb7d80749feebc22a74 (patch) | |
tree | 5a433a0d1ea7730d6dffe3f5db72c866535b7d0d | |
parent | f02e579558cf2aba06ecc7d4515661286b60f411 (diff) | |
download | linux-cef5975d453bbc1bbf29ceb7d80749feebc22a74.tar.xz |
[ARM] 4592/1: ns9xxx: clocksource driver
Signed-off-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r-- | arch/arm/Kconfig | 1 | ||||
-rw-r--r-- | arch/arm/mach-ns9xxx/time.c | 68 |
2 files changed, 43 insertions, 26 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 6acc59d..a43a814 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -319,6 +319,7 @@ config ARCH_KS8695 config ARCH_NS9XXX bool "NetSilicon NS9xxx" select GENERIC_GPIO + select GENERIC_TIME help Say Y here if you intend to run this kernel on a NetSilicon NS9xxx System. diff --git a/arch/arm/mach-ns9xxx/time.c b/arch/arm/mach-ns9xxx/time.c index 3327d30..d293455 100644 --- a/arch/arm/mach-ns9xxx/time.c +++ b/arch/arm/mach-ns9xxx/time.c @@ -11,6 +11,9 @@ #include <linux/jiffies.h> #include <linux/interrupt.h> #include <linux/irq.h> +#include <linux/stringify.h> +#include <linux/clocksource.h> + #include <asm/arch-ns9xxx/regs-sys.h> #include <asm/arch-ns9xxx/clock.h> #include <asm/arch-ns9xxx/irqs.h> @@ -18,8 +21,7 @@ #include "generic.h" #define TIMERCLOCKSELECT 64 - -static u32 usecs_per_tick; +#define TIMER_CLOCKSOURCE 1 static irqreturn_t ns9xxx_timer_interrupt(int irq, void *dev_id) @@ -45,39 +47,30 @@ ns9xxx_timer_interrupt(int irq, void *dev_id) return IRQ_HANDLED; } -static unsigned long ns9xxx_timer_gettimeoffset(void) -{ - /* return the microseconds which have passed since the last interrupt - * was _serviced_. That is, if an interrupt is pending or the counter - * reloads, return one period more. */ - - u32 counter1 = SYS_TR(0); - int pending = SYS_ISR & (1 << IRQ_TIMER0); - u32 counter2 = SYS_TR(0); - u32 elapsed; - - if (pending || counter2 > counter1) - elapsed = 2 * SYS_TRC(0) - counter2; - else - elapsed = SYS_TRC(0) - counter1; - - return (elapsed * usecs_per_tick) >> 16; - -} - static struct irqaction ns9xxx_timer_irq = { .name = "NS9xxx Timer Tick", .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, .handler = ns9xxx_timer_interrupt, }; +static cycle_t ns9xxx_clocksource_read(void) +{ + return SYS_TR(TIMER_CLOCKSOURCE); +} + +static struct clocksource ns9xxx_clocksource = { + .name = "ns9xxx-timer" __stringify(TIMER_CLOCKSOURCE), + .rating = 300, + .read = ns9xxx_clocksource_read, + .mask = CLOCKSOURCE_MASK(32), + .shift = 20, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + static void __init ns9xxx_timer_init(void) { int tc; - usecs_per_tick = - SH_DIV(1000000 * TIMERCLOCKSELECT, ns9xxx_cpuclock(), 16); - /* disable timer */ if ((tc = SYS_TC(0)) & SYS_TCx_TEN) SYS_TC(0) = tc & ~SYS_TCx_TEN; @@ -94,9 +87,32 @@ static void __init ns9xxx_timer_init(void) SYS_TC(0) = tc; setup_irq(IRQ_TIMER0, &ns9xxx_timer_irq); + + tc = SYS_TC(TIMER_CLOCKSOURCE); + if (REGGET(tc, SYS_TCx, TEN)) { + REGSET(tc, SYS_TCx, TEN, DIS); + SYS_TC(TIMER_CLOCKSOURCE) = tc; + } + + SYS_TRC(TIMER_CLOCKSOURCE) = 0; + + REGSET(tc, SYS_TCx, TEN, EN); + REGSET(tc, SYS_TCx, TDBG, STOP); + REGSET(tc, SYS_TCx, TLCS, CPU); + REGSET(tc, SYS_TCx, TM, IEE); + REGSET(tc, SYS_TCx, INTS, DIS); + REGSET(tc, SYS_TCx, UDS, UP); + REGSET(tc, SYS_TCx, TSZ, 32); + REGSET(tc, SYS_TCx, REN, EN); + + SYS_TC(TIMER_CLOCKSOURCE) = tc; + + ns9xxx_clocksource.mult = clocksource_hz2mult(ns9xxx_cpuclock(), + ns9xxx_clocksource.shift); + + clocksource_register(&ns9xxx_clocksource); } struct sys_timer ns9xxx_timer = { .init = ns9xxx_timer_init, - .offset = ns9xxx_timer_gettimeoffset, }; |