diff options
author | Ralf Baechle <ralf@linux-mips.org> | 2007-10-18 12:34:12 (GMT) |
---|---|---|
committer | Ralf Baechle <ralf@linux-mips.org> | 2007-10-18 17:11:47 (GMT) |
commit | e887b24592c5ddf46d37e592b2ee6bd2188257e1 (patch) | |
tree | 802956f841441d87dc472240c9eee87f6a574f46 /arch/mips/sgi-ip27/ip27-timer.c | |
parent | 832348ff0bf1538e026ff862f91ab6db06e73499 (diff) | |
download | linux-fsl-qoriq-e887b24592c5ddf46d37e592b2ee6bd2188257e1.tar.xz |
[MIPS] IP27: Convert to clock_event_device.
This separates the tick timer stuff from the generic MIPS time.c.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/sgi-ip27/ip27-timer.c')
-rw-r--r-- | arch/mips/sgi-ip27/ip27-timer.c | 155 |
1 files changed, 92 insertions, 63 deletions
diff --git a/arch/mips/sgi-ip27/ip27-timer.c b/arch/mips/sgi-ip27/ip27-timer.c index b7b3479..d467bf4 100644 --- a/arch/mips/sgi-ip27/ip27-timer.c +++ b/arch/mips/sgi-ip27/ip27-timer.c @@ -3,6 +3,7 @@ * Copytight (C) 1999, 2000 Silicon Graphics, Inc. */ #include <linux/bcd.h> +#include <linux/clockchips.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/sched.h> @@ -25,22 +26,8 @@ #include <asm/sn/sn0/ip27.h> #include <asm/sn/sn0/hub.h> -/* - * This is a hack; we really need to figure these values out dynamically - * - * Since 800 ns works very well with various HUB frequencies, such as - * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time. - * - * Ralf: which clock rate is used to feed the counter? - */ -#define NSEC_PER_CYCLE 800 -#define CYCLES_PER_SEC (NSEC_PER_SEC/NSEC_PER_CYCLE) -#define CYCLES_PER_JIFFY (CYCLES_PER_SEC/HZ) - #define TICK_SIZE (tick_nsec / 1000) -static unsigned long ct_cur[NR_CPUS]; /* What counter should be at next timer irq */ - #if 0 static int set_rtc_mmss(unsigned long nowtime) { @@ -86,36 +73,6 @@ static int set_rtc_mmss(unsigned long nowtime) } #endif -static unsigned int rt_timer_irq; - -void ip27_rt_timer_interrupt(void) -{ - int cpu = smp_processor_id(); - int cpuA = cputoslice(cpu) == 0; - unsigned int irq = rt_timer_irq; - - irq_enter(); - write_seqlock(&xtime_lock); - -again: - LOCAL_HUB_S(cpuA ? PI_RT_PEND_A : PI_RT_PEND_B, 0); /* Ack */ - ct_cur[cpu] += CYCLES_PER_JIFFY; - LOCAL_HUB_S(cpuA ? PI_RT_COMPARE_A : PI_RT_COMPARE_B, ct_cur[cpu]); - - if (LOCAL_HUB_L(PI_RT_COUNT) >= ct_cur[cpu]) - goto again; - - kstat_this_cpu.irqs[irq]++; /* kstat only for bootcpu? */ - - if (cpu == 0) - do_timer(1); - - update_process_times(user_mode(get_irq_regs())); - - write_sequnlock(&xtime_lock); - irq_exit(); -} - /* Includes for ioc3_init(). */ #include <asm/sn/types.h> #include <asm/sn/sn0/addrs.h> @@ -154,6 +111,46 @@ unsigned long read_persistent_clock(void) return mktime(year, month, date, hour, min, sec); } +static int rt_set_next_event(unsigned long delta, + struct clock_event_device *evt) +{ + unsigned int cpu = smp_processor_id(); + int slice = cputoslice(cpu) == 0; + unsigned long cnt; + + cnt = LOCAL_HUB_L(PI_RT_COUNT); + cnt += delta; + LOCAL_HUB_S(slice ? PI_RT_COMPARE_A : PI_RT_COMPARE_B, cnt); + + return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0; +} + +static void rt_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + /* The only mode supported */ + break; + + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_ONESHOT: + case CLOCK_EVT_MODE_RESUME: + /* Nothing to do */ + break; + } +} + +struct clock_event_device rt_clock_event_device = { + .name = "HUB-RT", + .features = CLOCK_EVT_FEAT_ONESHOT, + + .rating = 300, + .set_next_event = rt_set_next_event, + .set_mode = rt_set_mode, +}; + static void enable_rt_irq(unsigned int irq) { } @@ -171,6 +168,20 @@ static struct irq_chip rt_irq_type = { .eoi = enable_rt_irq, }; +unsigned int rt_timer_irq; + +static irqreturn_t ip27_rt_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *cd = &rt_clock_event_device; + unsigned int cpu = smp_processor_id(); + int slice = cputoslice(cpu) == 0; + + LOCAL_HUB_S(slice ? PI_RT_PEND_A : PI_RT_PEND_B, 0); /* Ack */ + cd->event_handler(cd); + + return IRQ_HANDLED; +} + static struct irqaction rt_irqaction = { .handler = (irq_handler_t) ip27_rt_timer_interrupt, .flags = IRQF_DISABLED, @@ -178,26 +189,43 @@ static struct irqaction rt_irqaction = { .name = "timer" }; -void __init plat_timer_setup(struct irqaction *irq) +/* + * This is a hack; we really need to figure these values out dynamically + * + * Since 800 ns works very well with various HUB frequencies, such as + * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time. + * + * Ralf: which clock rate is used to feed the counter? + */ +#define NSEC_PER_CYCLE 800 +#define CYCLES_PER_SEC (NSEC_PER_SEC / NSEC_PER_CYCLE) + +static void __init ip27_rt_clock_event_init(void) { - int irqno = allocate_irqno(); + struct clock_event_device *cd = &rt_clock_event_device; + unsigned int cpu = smp_processor_id(); + int irq = allocate_irqno(); - if (irqno < 0) + if (irq < 0) panic("Can't allocate interrupt number for timer interrupt"); - set_irq_chip_and_handler(irqno, &rt_irq_type, handle_percpu_irq); + rt_timer_irq = irq; - /* over-write the handler, we use our own way */ - irq->handler = no_action; + cd->irq = irq, + cd->cpumask = cpumask_of_cpu(cpu), - /* setup irqaction */ - irq_desc[irqno].status |= IRQ_PER_CPU; - - rt_timer_irq = irqno; /* - * Only needed to get /proc/interrupt to display timer irq stats + * Calculate the min / max delta */ - setup_irq(irqno, &rt_irqaction); + cd->mult = + div_sc((unsigned long) CYCLES_PER_SEC, NSEC_PER_SEC, 32); + cd->shift = 32; + cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd); + cd->min_delta_ns = clockevent_delta2ns(0x300, cd); + clockevents_register_device(cd); + + set_irq_chip_and_handler(irq, &rt_irq_type, handle_percpu_irq); + setup_irq(irq, &rt_irqaction); } static cycle_t hub_rt_read(void) @@ -206,7 +234,7 @@ static cycle_t hub_rt_read(void) } struct clocksource ht_rt_clocksource = { - .name = "HUB", + .name = "HUB-RT", .rating = 200, .read = hub_rt_read, .mask = CLOCKSOURCE_MASK(52), @@ -214,11 +242,17 @@ struct clocksource ht_rt_clocksource = { .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; -void __init plat_time_init(void) +static void __init ip27_rt_clocksource_init(void) { clocksource_register(&ht_rt_clocksource); } +void __init plat_time_init(void) +{ + ip27_rt_clock_event_init(); + ip27_rt_clocksource_init(); +} + void __init cpu_time_init(void) { lboard_t *board; @@ -248,17 +282,12 @@ void __init hub_rtc_init(cnodeid_t cnode) * node and timeouts will not happen there. */ if (get_compact_nodeid() == cnode) { - int cpu = smp_processor_id(); LOCAL_HUB_S(PI_RT_EN_A, 1); LOCAL_HUB_S(PI_RT_EN_B, 1); LOCAL_HUB_S(PI_PROF_EN_A, 0); LOCAL_HUB_S(PI_PROF_EN_B, 0); - ct_cur[cpu] = CYCLES_PER_JIFFY; - LOCAL_HUB_S(PI_RT_COMPARE_A, ct_cur[cpu]); LOCAL_HUB_S(PI_RT_COUNT, 0); LOCAL_HUB_S(PI_RT_PEND_A, 0); - LOCAL_HUB_S(PI_RT_COMPARE_B, ct_cur[cpu]); - LOCAL_HUB_S(PI_RT_COUNT, 0); LOCAL_HUB_S(PI_RT_PEND_B, 0); } } |