diff options
| -rw-r--r-- | arch/arm/Kconfig | 1 | ||||
| -rw-r--r-- | arch/arm/include/asm/hardware/iop3xx.h | 12 | ||||
| -rw-r--r-- | arch/arm/mach-iop13xx/include/mach/time.h | 12 | ||||
| -rw-r--r-- | arch/arm/plat-iop/time.c | 101 |
4 files changed, 115 insertions, 11 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 1c4119c6004..e732fcc3052 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -810,6 +810,7 @@ config ARCH_ACORN config PLAT_IOP bool + select GENERIC_CLOCKEVENTS config PLAT_ORION bool diff --git a/arch/arm/include/asm/hardware/iop3xx.h b/arch/arm/include/asm/hardware/iop3xx.h index 643b7b95b25..34601b95204 100644 --- a/arch/arm/include/asm/hardware/iop3xx.h +++ b/arch/arm/include/asm/hardware/iop3xx.h @@ -236,6 +236,13 @@ void iop_init_cp6_handler(void); void iop_init_time(unsigned long tickrate); unsigned long iop_gettimeoffset(void); +static inline u32 read_tmr0(void) +{ + u32 val; + asm volatile("mrc p6, 0, %0, c0, c1, 0" : "=r" (val)); + return val; +} + static inline void write_tmr0(u32 val) { asm volatile("mcr p6, 0, %0, c0, c1, 0" : : "r" (val)); @@ -253,6 +260,11 @@ static inline u32 read_tcr0(void) return val; } +static inline void write_tcr0(u32 val) +{ + asm volatile("mcr p6, 0, %0, c2, c1, 0" : : "r" (val)); +} + static inline u32 read_tcr1(void) { u32 val; diff --git a/arch/arm/mach-iop13xx/include/mach/time.h b/arch/arm/mach-iop13xx/include/mach/time.h index 9fb2768c84b..b2fb17b3542 100644 --- a/arch/arm/mach-iop13xx/include/mach/time.h +++ b/arch/arm/mach-iop13xx/include/mach/time.h @@ -66,6 +66,13 @@ static inline unsigned long iop13xx_xsi_bus_ratio(void) return 2; } +static inline u32 read_tmr0(void) +{ + u32 val; + asm volatile("mrc p6, 0, %0, c0, c9, 0" : "=r" (val)); + return val; +} + static inline void write_tmr0(u32 val) { asm volatile("mcr p6, 0, %0, c0, c9, 0" : : "r" (val)); @@ -83,6 +90,11 @@ static inline u32 read_tcr0(void) return val; } +static inline void write_tcr0(u32 val) +{ + asm volatile("mcr p6, 0, %0, c2, c9, 0" : : "r" (val)); +} + static inline u32 read_tcr1(void) { u32 val; diff --git a/arch/arm/plat-iop/time.c b/arch/arm/plat-iop/time.c index 5506c9b4561..a550e96394a 100644 --- a/arch/arm/plat-iop/time.c +++ b/arch/arm/plat-iop/time.c @@ -20,6 +20,7 @@ #include <linux/timex.h> #include <linux/io.h> #include <linux/clocksource.h> +#include <linux/clockchips.h> #include <mach/hardware.h> #include <asm/irq.h> #include <asm/uaccess.h> @@ -64,7 +65,81 @@ static void __init iop_clocksource_set_hz(struct clocksource *cs, unsigned int h cs->name, cs->shift, cs->mult); } +/* + * IOP clockevents (interrupting timer 0). + */ +static int iop_set_next_event(unsigned long delta, + struct clock_event_device *unused) +{ + u32 tmr = IOP_TMR_PRIVILEGED | IOP_TMR_RATIO_1_1; + + BUG_ON(delta == 0); + write_tmr0(tmr & ~(IOP_TMR_EN | IOP_TMR_RELOAD)); + write_tcr0(delta); + write_tmr0((tmr & ~IOP_TMR_RELOAD) | IOP_TMR_EN); + + return 0; +} + static unsigned long ticks_per_jiffy; + +static void iop_set_mode(enum clock_event_mode mode, + struct clock_event_device *unused) +{ + u32 tmr = read_tmr0(); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + write_tmr0(tmr & ~IOP_TMR_EN); + write_tcr0(ticks_per_jiffy - 1); + tmr |= (IOP_TMR_RELOAD | IOP_TMR_EN); + break; + case CLOCK_EVT_MODE_ONESHOT: + /* ->set_next_event sets period and enables timer */ + tmr &= ~(IOP_TMR_RELOAD | IOP_TMR_EN); + break; + case CLOCK_EVT_MODE_RESUME: + tmr |= IOP_TMR_EN; + break; + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_UNUSED: + default: + tmr &= ~IOP_TMR_EN; + break; + } + + write_tmr0(tmr); +} + +static struct clock_event_device iop_clockevent = { + .name = "iop_timer0", + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .rating = 300, + .set_next_event = iop_set_next_event, + .set_mode = iop_set_mode, +}; + +static void __init iop_clockevent_set_hz(struct clock_event_device *ce, unsigned int hz) +{ + u64 temp; + u32 shift; + + /* Find shift and mult values for hz. */ + shift = 32; + do { + temp = (u64) hz << shift; + do_div(temp, NSEC_PER_SEC); + if ((temp >> 32) == 0) + break; + } while (--shift != 0); + + ce->shift = shift; + ce->mult = (u32) temp; + + printk(KERN_INFO "clockevent: %s uses shift %u mult %#lx\n", + ce->name, ce->shift, ce->mult); +} + static unsigned long ticks_per_usec; static unsigned long next_jiffy_time; @@ -95,14 +170,10 @@ unsigned long iop_gettimeoffset(void) static irqreturn_t iop_timer_interrupt(int irq, void *dev_id) { - write_tisr(1); - - while ((signed long)(next_jiffy_time - read_tcr1()) - >= ticks_per_jiffy) { - timer_tick(); - next_jiffy_time -= ticks_per_jiffy; - } + struct clock_event_device *evt = dev_id; + write_tisr(1); + evt->event_handler(evt); return IRQ_HANDLED; } @@ -110,6 +181,7 @@ static struct irqaction iop_timer_irq = { .name = "IOP Timer Tick", .handler = iop_timer_interrupt, .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, + .dev_id = &iop_clockevent, }; static unsigned long iop_tick_rate; @@ -132,10 +204,19 @@ void __init iop_init_time(unsigned long tick_rate) IOP_TMR_RELOAD | IOP_TMR_RATIO_1_1; /* - * We use timer 0 for our timer interrupt, and timer 1 as - * monotonic counter for tracking missed jiffies. + * Set up interrupting clockevent timer 0. */ + write_tmr0(timer_ctl & ~IOP_TMR_EN); + setup_irq(IRQ_IOP_TIMER0, &iop_timer_irq); + iop_clockevent_set_hz(&iop_clockevent, tick_rate); + iop_clockevent.max_delta_ns = + clockevent_delta2ns(0xfffffffe, &iop_clockevent); + iop_clockevent.min_delta_ns = + clockevent_delta2ns(0xf, &iop_clockevent); + iop_clockevent.cpumask = cpumask_of(0); + clockevents_register_device(&iop_clockevent); write_trr0(ticks_per_jiffy - 1); + write_tcr0(ticks_per_jiffy - 1); write_tmr0(timer_ctl); /* @@ -146,6 +227,4 @@ void __init iop_init_time(unsigned long tick_rate) write_tmr1(timer_ctl); iop_clocksource_set_hz(&iop_clocksource, tick_rate); clocksource_register(&iop_clocksource); - - setup_irq(IRQ_IOP_TIMER0, &iop_timer_irq); } |