Hello Thomas, Sascha and Ingo please can you find some time to review next patch arm: i.MX/MX1 clock event source which has been sent to you and to the ALKML at 2007-01-13.
http://thread.gmane.org/gmane.linux.ports.arm.kernel/29510/focus=29533 There seems to be some problems, because this patch has not been accepted to patch-2.6.20-rc5-rt7.patch, but GENERIC_CLOCKEVENTS are set already for i.MX and this results in a problems to run RT kernel on this architecture. config ARCH_IMX bool "IMX" + select GENERIC_TIME + select GENERIC_CLOCKEVENTS Thanks for review and your time 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 | 92 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 92 insertions(+) Index: linux-2.6.20-rc4/arch/arm/mach-imx/time.c =================================================================== --- linux-2.6.20-rc4.orig/arch/arm/mach-imx/time.c +++ linux-2.6.20-rc4/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_PERIODIC; +#endif + static unsigned long evt_diff; /* @@ -42,9 +50,16 @@ 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(); + if (likely(clockevent_mode != CLOCK_EVT_PERIODIC)) + break; +#else write_seqlock(&xtime_lock); timer_tick(); write_sequnlock(&xtime_lock); +#endif IMX_TCMP(TIMER_BASE) += evt_diff; } while (unlikely((int32_t)(IMX_TCMP(TIMER_BASE) @@ -99,11 +114,88 @@ static int __init imx_clocksource_init(v return 0; } +#ifdef CONFIG_GENERIC_CLOCKEVENTS + +static void imx_set_next_event(unsigned long evt, + struct clock_event_device *unused) +{ + evt_diff = evt; + IMX_TCMP(TIMER_BASE) = IMX_TCN(TIMER_BASE) + evt; +} + +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_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; + } + /* Remember timer mode */ + clockevent_mode = mode; + local_irq_restore(flags); + + switch (mode) { + case CLOCK_EVT_PERIODIC: + case CLOCK_EVT_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_SHUTDOWN: + /* Left event sources disabled, no more interrupts appears */ + break; + } +} + +static struct clock_event_device clockevent_imx = { + .name = "imx_timer1", + .capabilities = CLOCK_CAP_NEXTEVT | CLOCK_CAP_TICK | + CLOCK_CAP_UPDATE | CLOCK_CAP_PROFILE, + .shift = 32, + .set_mode = imx_set_mode, + .set_next_event = imx_set_next_event, +}; + +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); + register_local_clockevent(&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/
