Messages in this thread Patch in this message | | | Subject | Re: [patch-rt 0/2] Initial ARM generic-timeofday support | From | Kevin Hilman <> | Date | Tue, 06 Jun 2006 13:05:16 -0700 |
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On Mon, 2006-06-05 at 15:29 -0700, dsaxena@plexity.net wrote: > patchset (against -rt26, but should apply to newer patch) adds > initial support for generic TOD on ARM. It is fairly simple and > copletely rips out the existing TOD code in ARM, assuming that each > sub-arch will either provide a clocksource or enable CONFIG_IS_TICK_BASED. > Currently only Versatile is supported.
And here's a patch on top of the ARM support which adds a clocksource for the ixp4xx platform.
Kevin
Add a clocksource driver for the Intel IXP4xx platform allowing it to use the generic time-of-day code.
Signed-off-by: Kevin Hilman <khilman@deeprooted.net>
Index: ixp4xx/arch/arm/mach-ixp4xx/common.c =================================================================== --- ixp4xx.orig/arch/arm/mach-ixp4xx/common.c +++ ixp4xx/arch/arm/mach-ixp4xx/common.c @@ -27,6 +27,7 @@ #include <linux/bitops.h> #include <linux/time.h> #include <linux/timex.h> +#include <linux/clocksource.h> #include <asm/hardware.h> #include <asm/uaccess.h> @@ -253,16 +254,6 @@ static unsigned volatile last_jiffy_time #define CLOCK_TICKS_PER_USEC ((CLOCK_TICK_RATE + USEC_PER_SEC/2) / USEC_PER_SEC) -/* IRQs are disabled before entering here from do_gettimeofday() */ -static unsigned long ixp4xx_gettimeoffset(void) -{ - u32 elapsed; - - elapsed = *IXP4XX_OSTS - last_jiffy_time; - - return elapsed / CLOCK_TICKS_PER_USEC; -} - static irqreturn_t ixp4xx_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) { write_seqlock(&xtime_lock); @@ -297,8 +288,6 @@ static void __init ixp4xx_timer_init(voi /* Setup the Timer counter value */ *IXP4XX_OSRT1 = (LATCH & ~IXP4XX_OST_RELOAD_MASK) | IXP4XX_OST_ENABLE; - /* Reset time-stamp counter */ - *IXP4XX_OSTS = 0; last_jiffy_time = 0; /* Connect the interrupt handler and enable the interrupt */ @@ -307,7 +296,6 @@ static void __init ixp4xx_timer_init(voi struct sys_timer ixp4xx_timer = { .init = ixp4xx_timer_init, - .offset = ixp4xx_gettimeoffset, }; static struct resource ixp46x_i2c_resources[] = { @@ -363,3 +351,30 @@ void __init ixp4xx_sys_init(void) ixp4xx_exp_bus_size >> 20); } +cycle_t ixp4xx_get_cycles(void) +{ + return *IXP4XX_OSTS; +} + +static struct clocksource clocksource_ixp4xx = { + .name = "OSTS", + .rating = 200, + .read = ixp4xx_get_cycles, + .mask = 0xFFFFFFFF, + .shift = 10, + .is_continuous = 1, +}; + +static int __init ixp4xx_clocksource_init(void) +{ + /* Reset time-stamp counter */ + *IXP4XX_OSTS = 0; + + clocksource_ixp4xx.mult = + clocksource_khz2mult(66660, clocksource_ixp4xx.shift); + register_clocksource(&clocksource_ixp4xx); + + return 0; +} + +device_initcall(ixp4xx_clocksource_init); | |