diff options
Diffstat (limited to 'arch/arm/mach-at91rm9200/time.c')
| -rw-r--r-- | arch/arm/mach-at91rm9200/time.c | 57 |
1 files changed, 36 insertions, 21 deletions
diff --git a/arch/arm/mach-at91rm9200/time.c b/arch/arm/mach-at91rm9200/time.c index 7ffcf44..fc2d7d5 100644 --- a/arch/arm/mach-at91rm9200/time.c +++ b/arch/arm/mach-at91rm9200/time.c @@ -31,6 +31,8 @@ #include <asm/irq.h> #include <asm/mach/time.h> +static unsigned long last_crtr; + /* * The ST_CRTR is updated asynchronously to the master clock. It is therefore * necessary to read it twice (with the same value) to ensure accuracy. @@ -56,7 +58,7 @@ static unsigned long at91rm9200_gettimeoffset(void) { unsigned long elapsed; - elapsed = (read_CRTR() - at91_sys_read(AT91_ST_RTAR)) & AT91_ST_ALMV; + elapsed = (read_CRTR() - last_crtr) & AT91_ST_ALMV; return (unsigned long)(elapsed * (tick_nsec / 1000)) / LATCH; } @@ -66,15 +68,12 @@ static unsigned long at91rm9200_gettimeoffset(void) */ static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) { - unsigned long rtar; - if (at91_sys_read(AT91_ST_SR) & AT91_ST_PITS) { /* This is a shared interrupt */ write_seqlock(&xtime_lock); - while (((read_CRTR() - at91_sys_read(AT91_ST_RTAR)) & AT91_ST_ALMV) >= LATCH) { + while (((read_CRTR() - last_crtr) & AT91_ST_ALMV) >= LATCH) { timer_tick(regs); - rtar = (at91_sys_read(AT91_ST_RTAR) + LATCH) & AT91_ST_ALMV; - at91_sys_write(AT91_ST_RTAR, rtar); + last_crtr = (last_crtr + LATCH) & AT91_ST_ALMV; } write_sequnlock(&xtime_lock); @@ -87,10 +86,24 @@ static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id, struct pt_r static struct irqaction at91rm9200_timer_irq = { .name = "at91_tick", - .flags = SA_SHIRQ | SA_INTERRUPT, + .flags = SA_SHIRQ | SA_INTERRUPT | SA_TIMER, .handler = at91rm9200_timer_interrupt }; +void at91rm9200_timer_reset(void) +{ + last_crtr = 0; + + /* Real time counter incremented every 30.51758 microseconds */ + at91_sys_write(AT91_ST_RTMR, 1); + + /* Set Period Interval timer */ + at91_sys_write(AT91_ST_PIMR, LATCH); + + /* Enable Period Interval Timer interrupt */ + at91_sys_write(AT91_ST_IER, AT91_ST_PITS); +} + /* * Set up timer interrupt. */ @@ -100,28 +113,30 @@ void __init at91rm9200_timer_init(void) at91_sys_write(AT91_ST_IDR, AT91_ST_PITS | AT91_ST_WDOVF | AT91_ST_RTTINC | AT91_ST_ALMS); (void) at91_sys_read(AT91_ST_SR); /* Clear any pending interrupts */ - /* - * Make IRQs happen for the system timer. - */ + /* Make IRQs happen for the system timer */ setup_irq(AT91_ID_SYS, &at91rm9200_timer_irq); - /* Set initial alarm to 0 */ - at91_sys_write(AT91_ST_RTAR, 0); - - /* Real time counter incremented every 30.51758 microseconds */ - at91_sys_write(AT91_ST_RTMR, 1); - - /* Set Period Interval timer */ - at91_sys_write(AT91_ST_PIMR, LATCH); - /* Change the kernel's 'tick' value to 10009 usec. (the default is 10000) */ tick_usec = (LATCH * 1000000) / CLOCK_TICK_RATE; - /* Enable Period Interval Timer interrupt */ - at91_sys_write(AT91_ST_IER, AT91_ST_PITS); + /* Initialize and enable the timer interrupt */ + at91rm9200_timer_reset(); +} + +#ifdef CONFIG_PM +static void at91rm9200_timer_suspend(void) +{ + /* disable Period Interval Timer interrupt */ + at91_sys_write(AT91_ST_IDR, AT91_ST_PITS); } +#else +#define at91rm9200_timer_suspend NULL +#endif struct sys_timer at91rm9200_timer = { .init = at91rm9200_timer_init, .offset = at91rm9200_gettimeoffset, + .suspend = at91rm9200_timer_suspend, + .resume = at91rm9200_timer_reset, }; + |
