On Wednesday 24 January 2007 12:37, Thomas Gleixner wrote: > On Wed, 2007-01-24 at 03:00 +0100, Pavel Pisa wrote: > > stays NULL after clock event registration. Interrupts > > runs, but my code doesnot call any function. The notification > > chain and clock events list seems to be filled correctly. > > I have added > > > > clockevent_imx.cpumask = cpumask_of_cpu(0); > > Correct. I probably should disable the check for UP.
I have made mistake last time on 2.6.20-rc5-rt8. I have returned to testing today with 2.6.20-rc6-rt2. I have added checking outputs to the tickregistration routines, but all works correctly after right cpumask correction. I have rechecked even without additional printks and I have observed no problems. The clock events enabled kernels requires next minor changes to compile on ARM still ================================================================================ ================================================================================ arch/arm/kernel/process.c | 5 +++-- kernel/time/tick-sched.c | 1 + 2 files changed, 4 insertions(+), 2 deletions(-) Index: linux-2.6.20-rc6/kernel/time/tick-sched.c =================================================================== --- linux-2.6.20-rc6.orig/kernel/time/tick-sched.c +++ linux-2.6.20-rc6/kernel/time/tick-sched.c @@ -20,6 +20,7 @@ #include <linux/profile.h> #include <linux/sched.h> #include <linux/tick.h> +#include <asm/irq_regs.h> #include "tick-internal.h" Index: linux-2.6.20-rc6/arch/arm/kernel/process.c =================================================================== --- linux-2.6.20-rc6.orig/arch/arm/kernel/process.c +++ linux-2.6.20-rc6/arch/arm/kernel/process.c @@ -28,6 +28,7 @@ #include <linux/cpu.h> #include <linux/elfcore.h> #include <linux/pm.h> +#include <linux/tick.h> #include <asm/leds.h> #include <asm/processor.h> @@ -154,11 +155,11 @@ void cpu_idle(void) if (!idle) idle = default_idle; leds_event(led_idle_start); - hrtimer_stop_sched_tick(); + tick_nohz_stop_sched_tick(); while (!need_resched() && !need_resched_delayed()) idle(); leds_event(led_idle_end); - hrtimer_restart_sched_tick(); + tick_nohz_restart_sched_tick(); local_irq_disable(); __preempt_enable_no_resched(); __schedule(); ================================================================================ ================================================================================ Updated version of i.MX patch follows. If somebody wants it, I can send patch to revert code of previous version from full 2.6.20-rc6-rt2 patch. Ingo, please, can you replace i.MX1 patch in your series? Thanks Pavel ================================================================================ ================================================================================ Subject: arm: i.MX/MX1 clock event source Support clock event source based on i.MX general purpose timer in free running timer mode. Signed-off-by: Pavel Pisa <[EMAIL PROTECTED]> arch/arm/mach-imx/time.c | 130 +++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 125 insertions(+), 5 deletions(-) Index: linux-2.6.20-rc6/arch/arm/mach-imx/time.c =================================================================== --- linux-2.6.20-rc6.orig/arch/arm/mach-imx/time.c +++ linux-2.6.20-rc6/arch/arm/mach-imx/time.c @@ -15,6 +15,9 @@ #include <linux/irq.h> #include <linux/time.h> #include <linux/clocksource.h> +#ifdef CONFIG_GENERIC_CLOCKEVENTS +#include <linux/clockchips.h> +#endif #include <asm/hardware.h> #include <asm/io.h> @@ -25,6 +28,11 @@ /* Use timer 1 as system timer */ #define TIMER_BASE IMX_TIM1_BASE +#ifdef CONFIG_GENERIC_CLOCKEVENTS +static struct clock_event_device clockevent_imx; +static enum clock_event_mode clockevent_mode = CLOCK_EVT_MODE_PERIODIC; +#endif + static unsigned long evt_diff; /* @@ -33,6 +41,7 @@ static unsigned long evt_diff; static irqreturn_t imx_timer_interrupt(int irq, void *dev_id) { + unsigned long tcmp; uint32_t tstat; /* clear the interrupt */ @@ -42,13 +51,20 @@ imx_timer_interrupt(int irq, void *dev_i if (tstat & TSTAT_COMP) { do { +#ifdef CONFIG_GENERIC_CLOCKEVENTS + if (clockevent_imx.event_handler) + clockevent_imx.event_handler(&clockevent_imx); + if (likely(clockevent_mode != CLOCK_EVT_MODE_PERIODIC)) + break; +#else write_seqlock(&xtime_lock); timer_tick(); write_sequnlock(&xtime_lock); - IMX_TCMP(TIMER_BASE) += evt_diff; +#endif + tcmp = IMX_TCMP(TIMER_BASE) + evt_diff; + IMX_TCMP(TIMER_BASE) = tcmp; - } while (unlikely((int32_t)(IMX_TCMP(TIMER_BASE) - - IMX_TCN(TIMER_BASE)) < 0)); + } while (unlikely((int32_t)(tcmp - IMX_TCN(TIMER_BASE)) < 0)); } return IRQ_HANDLED; @@ -70,7 +86,7 @@ static void __init imx_timer_hardware_in */ IMX_TCTL(TIMER_BASE) = 0; IMX_TPRER(TIMER_BASE) = 0; - IMX_TCMP(TIMER_BASE) = LATCH - 1; + IMX_TCMP(TIMER_BASE) = IMX_TCN(TIMER_BASE) + LATCH; IMX_TCTL(TIMER_BASE) = TCTL_FRR | TCTL_CLK_PCLK1 | TCTL_IRQEN | TCTL_TEN; evt_diff = LATCH; @@ -87,7 +103,7 @@ static struct clocksource clocksource_im .read = imx_get_cycles, .mask = 0xFFFFFFFF, .shift = 20, - .is_continuous = 1, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; static int __init imx_clocksource_init(void) @@ -99,11 +115,115 @@ static int __init imx_clocksource_init(v return 0; } +#ifdef CONFIG_GENERIC_CLOCKEVENTS + +static int imx_set_next_event(unsigned long evt, + struct clock_event_device *unused) +{ + unsigned long tcmp; + evt_diff = evt; + + tcmp = IMX_TCN(TIMER_BASE) + evt; + IMX_TCMP(TIMER_BASE) = tcmp; + + return unlikely((int32_t)(tcmp - IMX_TCN(TIMER_BASE)) < 0) ? -ETIME : 0; +} + +#ifdef DEBUG +static const char *clock_event_mode_label[]={ + [CLOCK_EVT_MODE_PERIODIC] = "CLOCK_EVT_MODE_PERIODIC", + [CLOCK_EVT_MODE_ONESHOT] = "CLOCK_EVT_MODE_ONESHOT", + [CLOCK_EVT_MODE_SHUTDOWN] = "CLOCK_EVT_MODE_SHUTDOWN", + [CLOCK_EVT_MODE_UNUSED] = "CLOCK_EVT_MODE_UNUSED" +}; +#endif /*DEBUG*/ + +static void imx_set_mode(enum clock_event_mode mode, struct clock_event_device *evt) +{ + unsigned long flags; + + /* + * The timer interrupt generation is disabled at least + * for enough time to call imx_set_next_event() + */ + local_irq_save(flags); + /* Disable interrupt in GPT module */ + IMX_TCTL(TIMER_BASE) &= ~TCTL_IRQEN; + if ((mode != CLOCK_EVT_MODE_PERIODIC) || (mode != clockevent_mode)) { + /* Set event time into far-far future */ + IMX_TCMP(TIMER_BASE) = IMX_TCN(TIMER_BASE) - 3; + /* Clear pending interrupt */ + IMX_TSTAT(TIMER_BASE) &= ~TSTAT_COMP; + } + +#ifdef DEBUG + printk(KERN_INFO "imx_set_mode: changing mode from %s to %s\n", + clock_event_mode_label[clockevent_mode], clock_event_mode_label[mode]); +#endif /*DEBUG*/ + + /* Remember timer mode */ + clockevent_mode = mode; + local_irq_restore(flags); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + /* It seems, that periodic mode expects old ugly latch period */ + evt_diff = LATCH; + IMX_TCMP(TIMER_BASE) = IMX_TCN(TIMER_BASE) + evt_diff; + case CLOCK_EVT_MODE_ONESHOT: + /* + * Do not put overhead of interrupt enable/disable into + * imx_set_next_event(), the core has about 4 minutes + * to call imx_set_next_event() or shutdown clock after + * mode switching + */ + local_irq_save(flags); + IMX_TCTL(TIMER_BASE) |= TCTL_IRQEN; + local_irq_restore(flags); + break; + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_UNUSED: + /* Left event sources disabled, no more interrupts appears */ + break; + } +} + +static struct clock_event_device clockevent_imx = { + .name = "imx_timer1", + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .shift = 32, + .set_mode = imx_set_mode, + .set_next_event = imx_set_next_event, + .rating = 200, +}; + +static int __init imx_clockevent_init(void) +{ + clockevent_imx.mult = div_sc(imx_get_perclk1(), NSEC_PER_SEC, + clockevent_imx.shift); + clockevent_imx.max_delta_ns = + clockevent_delta2ns(0xfffffffe, &clockevent_imx); + clockevent_imx.min_delta_ns = + clockevent_delta2ns(0xf, &clockevent_imx); + + clockevent_imx.cpumask = cpumask_of_cpu(0); + + clockevents_register_device(&clockevent_imx); + + return 0; +} +#endif + + static void __init imx_timer_init(void) { imx_timer_hardware_init(); imx_clocksource_init(); +#ifdef CONFIG_GENERIC_CLOCKEVENTS + imx_clockevent_init(); +#endif + /* * Make irqs happen for the system timer */ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/