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| author | Kevin O'Connor <kevin@koconnor.net> | 2019-07-24 01:03:23 -0400 |
|---|---|---|
| committer | Kevin O'Connor <kevin@koconnor.net> | 2019-07-24 01:08:18 -0400 |
| commit | 79bd13dba714ceb8b5c4aad43400c75eb9061aa5 (patch) | |
| tree | 4fefc981f14c2d47f134cad7809393d0e909bc6b /src/generic/armcm_timer.c | |
| parent | 4e5ddff00bac76efd5bae61ab50164f045ccb578 (diff) | |
| download | kutter-79bd13dba714ceb8b5c4aad43400c75eb9061aa5.tar.gz kutter-79bd13dba714ceb8b5c4aad43400c75eb9061aa5.tar.xz kutter-79bd13dba714ceb8b5c4aad43400c75eb9061aa5.zip | |
armcm_timer: Support micro-controllers faster than 160Mhz
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Diffstat (limited to 'src/generic/armcm_timer.c')
| -rw-r--r-- | src/generic/armcm_timer.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/src/generic/armcm_timer.c b/src/generic/armcm_timer.c index 7f11cd68..dad768e4 100644 --- a/src/generic/armcm_timer.c +++ b/src/generic/armcm_timer.c @@ -68,6 +68,25 @@ udelay(uint32_t usecs) ; } +// On fast cpus, schedule a recurring timer so SysTick doesn't overflow +static uint_fast8_t +timer_wrap_event(struct timer *t) +{ + t->waketime += 0xffffff; + return SF_RESCHEDULE; +} +static struct timer wrap_timer = { + .func = timer_wrap_event, + .waketime = 0xffffff, +}; +void +timer_reset(void) +{ + if (CONFIG_CLOCK_FREQ > 0xffffff * 10) + sched_add_timer(&wrap_timer); +} +DECL_SHUTDOWN(timer_reset); + void timer_init(void) { @@ -76,6 +95,9 @@ timer_init(void) DWT->CTRL |= DWT_CTRL_CYCCNTENA_Msk; DWT->CYCCNT = 0; + // Schedule a recurring timer on fast cpus + timer_reset(); + // Enable SysTick irqstatus_t flag = irq_save(); NVIC_SetPriority(SysTick_IRQn, 2); |