diff options
| -rw-r--r-- | arch/arm/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm/mach-ixp4xx/common.c | 93 |
2 files changed, 75 insertions, 19 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 2d13b016612..2aadd0e1e58 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -266,6 +266,7 @@ config ARCH_IXP4XX bool "IXP4xx-based" depends on MMU select GENERIC_TIME + select GENERIC_CLOCKEVENTS help Support for Intel's IXP4XX (XScale) family of processors. diff --git a/arch/arm/mach-ixp4xx/common.c b/arch/arm/mach-ixp4xx/common.c index 45068c3d8dc..09edea9779e 100644 --- a/arch/arm/mach-ixp4xx/common.c +++ b/arch/arm/mach-ixp4xx/common.c @@ -27,6 +27,7 @@ #include <linux/time.h> #include <linux/timex.h> #include <linux/clocksource.h> +#include <linux/clockchips.h> #include <asm/arch/udc.h> #include <asm/hardware.h> @@ -41,6 +42,8 @@ #include <asm/mach/time.h> static int __init ixp4xx_clocksource_init(void); +static int __init ixp4xx_clockevent_init(void); +static struct clock_event_device clockevent_ixp4xx; /************************************************************************* * IXP4xx chipset I/O mapping @@ -239,52 +242,40 @@ void __init ixp4xx_init_irq(void) * counter as a source of real clock ticks to account for missed jiffies. *************************************************************************/ -static unsigned volatile last_jiffy_time; - -#define CLOCK_TICKS_PER_USEC ((CLOCK_TICK_RATE + USEC_PER_SEC/2) / USEC_PER_SEC) - static irqreturn_t ixp4xx_timer_interrupt(int irq, void *dev_id) { - write_seqlock(&xtime_lock); + struct clock_event_device *evt = &clockevent_ixp4xx; /* Clear Pending Interrupt by writing '1' to it */ *IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND; - /* - * Catch up with the real idea of time - */ - while ((signed long)(*IXP4XX_OSTS - last_jiffy_time) >= LATCH) { - timer_tick(); - last_jiffy_time += LATCH; - } - - write_sequnlock(&xtime_lock); + evt->event_handler(evt); return IRQ_HANDLED; } static struct irqaction ixp4xx_timer_irq = { - .name = "IXP4xx Timer Tick", + .name = "timer1", .flags = IRQF_DISABLED | IRQF_TIMER, .handler = ixp4xx_timer_interrupt, }; static void __init ixp4xx_timer_init(void) { + /* Reset/disable counter */ + *IXP4XX_OSRT1 = 0; + /* Clear Pending Interrupt by writing '1' to it */ *IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND; - /* 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 */ setup_irq(IRQ_IXP4XX_TIMER1, &ixp4xx_timer_irq); ixp4xx_clocksource_init(); + ixp4xx_clockevent_init(); } struct sys_timer ixp4xx_timer = { @@ -384,6 +375,9 @@ void __init ixp4xx_sys_init(void) ixp4xx_exp_bus_size >> 20); } +/* + * clocksource + */ cycle_t ixp4xx_get_cycles(void) { return *IXP4XX_OSTS; @@ -408,3 +402,64 @@ static int __init ixp4xx_clocksource_init(void) return 0; } + +/* + * clockevents + */ +static int ixp4xx_set_next_event(unsigned long evt, + struct clock_event_device *unused) +{ + unsigned long opts = *IXP4XX_OSRT1 & IXP4XX_OST_RELOAD_MASK; + + *IXP4XX_OSRT1 = (evt & ~IXP4XX_OST_RELOAD_MASK) | opts; + + return 0; +} + +static void ixp4xx_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + unsigned long opts, osrt = *IXP4XX_OSRT1 & ~IXP4XX_OST_RELOAD_MASK; + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + osrt = LATCH & ~IXP4XX_OST_RELOAD_MASK; + opts = IXP4XX_OST_ENABLE; + break; + case CLOCK_EVT_MODE_ONESHOT: + /* period set by 'set next_event' */ + osrt = 0; + opts = IXP4XX_OST_ENABLE | IXP4XX_OST_ONE_SHOT; + break; + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_UNUSED: + default: + osrt = opts = 0; + break; + } + + *IXP4XX_OSRT1 = osrt | opts; +} + +static struct clock_event_device clockevent_ixp4xx = { + .name = "ixp4xx timer1", + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .rating = 200, + .shift = 24, + .set_mode = ixp4xx_set_mode, + .set_next_event = ixp4xx_set_next_event, +}; + +static int __init ixp4xx_clockevent_init(void) +{ + clockevent_ixp4xx.mult = div_sc(FREQ, NSEC_PER_SEC, + clockevent_ixp4xx.shift); + clockevent_ixp4xx.max_delta_ns = + clockevent_delta2ns(0xfffffffe, &clockevent_ixp4xx); + clockevent_ixp4xx.min_delta_ns = + clockevent_delta2ns(0xf, &clockevent_ixp4xx); + clockevent_ixp4xx.cpumask = cpumask_of_cpu(0); + + clockevents_register_device(&clockevent_ixp4xx); + return 0; +} |