diff options
Diffstat (limited to 'arch/arm/mach-versatile/core.c')
| -rw-r--r-- | arch/arm/mach-versatile/core.c | 129 |
1 files changed, 85 insertions, 44 deletions
diff --git a/arch/arm/mach-versatile/core.c b/arch/arm/mach-versatile/core.c index bf71507c76f..1275aa7d2eb 100644 --- a/arch/arm/mach-versatile/core.c +++ b/arch/arm/mach-versatile/core.c @@ -26,6 +26,8 @@ #include <linux/interrupt.h> #include <linux/amba/bus.h> #include <linux/amba/clcd.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> #include <asm/cnt32_to_63.h> #include <asm/system.h> @@ -828,59 +830,61 @@ void __init versatile_init(void) #define TICKS2USECS(x) ((x) / TICKS_PER_uSEC) #endif -/* - * Returns number of ms since last clock interrupt. Note that interrupts - * will have been disabled by do_gettimeoffset() - */ -static unsigned long versatile_gettimeoffset(void) +static void timer_set_mode(enum clock_event_mode mode, + struct clock_event_device *clk) { - unsigned long ticks1, ticks2, status; + unsigned long ctrl; - /* - * Get the current number of ticks. Note that there is a race - * condition between us reading the timer and checking for - * an interrupt. We get around this by ensuring that the - * counter has not reloaded between our two reads. - */ - ticks2 = readl(TIMER0_VA_BASE + TIMER_VALUE) & 0xffff; - do { - ticks1 = ticks2; - status = __raw_readl(VA_IC_BASE + VIC_RAW_STATUS); - ticks2 = readl(TIMER0_VA_BASE + TIMER_VALUE) & 0xffff; - } while (ticks2 > ticks1); + switch(mode) { + case CLOCK_EVT_MODE_PERIODIC: + writel(TIMER_RELOAD, TIMER0_VA_BASE + TIMER_LOAD); - /* - * Number of ticks since last interrupt. - */ - ticks1 = TIMER_RELOAD - ticks2; + ctrl = TIMER_CTRL_PERIODIC; + ctrl |= TIMER_CTRL_32BIT | TIMER_CTRL_IE | TIMER_CTRL_ENABLE; + break; + case CLOCK_EVT_MODE_ONESHOT: + /* period set, and timer enabled in 'next_event' hook */ + ctrl = TIMER_CTRL_ONESHOT; + ctrl |= TIMER_CTRL_32BIT | TIMER_CTRL_IE; + break; + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + default: + ctrl = 0; + } - /* - * Interrupt pending? If so, we've reloaded once already. - * - * FIXME: Need to check this is effectively timer 0 that expires - */ - if (status & IRQMASK_TIMERINT0_1) - ticks1 += TIMER_RELOAD; + writel(ctrl, TIMER0_VA_BASE + TIMER_CTRL); +} - /* - * Convert the ticks to usecs - */ - return TICKS2USECS(ticks1); +static int timer_set_next_event(unsigned long evt, + struct clock_event_device *unused) +{ + unsigned long ctrl = readl(TIMER0_VA_BASE + TIMER_CTRL); + + writel(evt, TIMER0_VA_BASE + TIMER_LOAD); + writel(ctrl | TIMER_CTRL_ENABLE, TIMER0_VA_BASE + TIMER_CTRL); + + return 0; } +static struct clock_event_device timer0_clockevent = { + .name = "timer0", + .shift = 32, + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .set_mode = timer_set_mode, + .set_next_event = timer_set_next_event, +}; + /* * IRQ handler for the timer */ static irqreturn_t versatile_timer_interrupt(int irq, void *dev_id) { - write_seqlock(&xtime_lock); + struct clock_event_device *evt = &timer0_clockevent; - // ...clear the interrupt writel(1, TIMER0_VA_BASE + TIMER_INTCLR); - timer_tick(); - - write_sequnlock(&xtime_lock); + evt->event_handler(evt); return IRQ_HANDLED; } @@ -891,6 +895,36 @@ static struct irqaction versatile_timer_irq = { .handler = versatile_timer_interrupt, }; +static cycle_t versatile_get_cycles(void) +{ + return ~readl(TIMER3_VA_BASE + TIMER_VALUE); +} + +static struct clocksource clocksource_versatile = { + .name = "timer3", + .rating = 200, + .read = versatile_get_cycles, + .mask = CLOCKSOURCE_MASK(32), + .shift = 20, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static int __init versatile_clocksource_init(void) +{ + /* setup timer3 as free-running clocksource */ + writel(0, TIMER3_VA_BASE + TIMER_CTRL); + writel(0xffffffff, TIMER3_VA_BASE + TIMER_LOAD); + writel(0xffffffff, TIMER3_VA_BASE + TIMER_VALUE); + writel(TIMER_CTRL_32BIT | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC, + TIMER3_VA_BASE + TIMER_CTRL); + + clocksource_versatile.mult = + clocksource_khz2mult(1000, clocksource_versatile.shift); + clocksource_register(&clocksource_versatile); + + return 0; +} + /* * Set up timer interrupt, and return the current time in seconds. */ @@ -918,18 +952,25 @@ static void __init versatile_timer_init(void) writel(0, TIMER2_VA_BASE + TIMER_CTRL); writel(0, TIMER3_VA_BASE + TIMER_CTRL); - writel(TIMER_RELOAD, TIMER0_VA_BASE + TIMER_LOAD); - writel(TIMER_RELOAD, TIMER0_VA_BASE + TIMER_VALUE); - writel(TIMER_DIVISOR | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC | - TIMER_CTRL_IE, TIMER0_VA_BASE + TIMER_CTRL); - /* * Make irqs happen for the system timer */ setup_irq(IRQ_TIMERINT0_1, &versatile_timer_irq); + + versatile_clocksource_init(); + + timer0_clockevent.mult = + div_sc(1000000, NSEC_PER_SEC, timer0_clockevent.shift); + timer0_clockevent.max_delta_ns = + clockevent_delta2ns(0xffffffff, &timer0_clockevent); + timer0_clockevent.min_delta_ns = + clockevent_delta2ns(0xf, &timer0_clockevent); + + timer0_clockevent.cpumask = cpumask_of_cpu(0); + clockevents_register_device(&timer0_clockevent); } struct sys_timer versatile_timer = { .init = versatile_timer_init, - .offset = versatile_gettimeoffset, }; + |