diff options
Diffstat (limited to 'wirish/HardwareTimer.cpp')
-rw-r--r-- | wirish/HardwareTimer.cpp | 65 |
1 files changed, 37 insertions, 28 deletions
diff --git a/wirish/HardwareTimer.cpp b/wirish/HardwareTimer.cpp index bd61a89..4f68ad7 100644 --- a/wirish/HardwareTimer.cpp +++ b/wirish/HardwareTimer.cpp @@ -24,39 +24,47 @@ * SOFTWARE. *****************************************************************************/ -#include "HardwareTimer.h" -#include "boards.h" // for CYCLES_PER_MICROSECOND -#include "wirish_math.h" +#include <wirish/HardwareTimer.h> + +#include <libmaple/rcc.h> +#include <wirish/ext_interrupts.h> // for noInterrupts(), interrupts() +#include <wirish/wirish_math.h> +#include <board/board.h> // for CYCLES_PER_MICROSECOND // TODO [0.1.0] Remove deprecated pieces -#ifdef STM32_MEDIUM_DENSITY -#define NR_TIMERS 4 -#elif defined(STM32_HIGH_DENSITY) -#define NR_TIMERS 8 -#else -#error "Unsupported density" -#endif +/* + * Evil hack to infer this->dev from timerNum in the HardwareTimer + * constructor. See: + * + * http://www.parashift.com/c++-faq-lite/pointers-to-members.html#faq-33.2 + * http://yosefk.com/c++fqa/function.html#fqa-33.2 + */ + +extern "C" { + static timer_dev **this_devp; + static rcc_clk_id this_id; + static void set_this_dev(timer_dev *dev) { + if (dev->clk_id == this_id) { + *this_devp = dev; + } + } +} -#define MAX_RELOAD ((1 << 16) - 1) +/* + * HardwareTimer routines + */ HardwareTimer::HardwareTimer(uint8 timerNum) { - if (timerNum > NR_TIMERS) { - ASSERT(0); - } - timer_dev *devs[] = { - TIMER1, - TIMER2, - TIMER3, - TIMER4, -#ifdef STM32_HIGH_DENSITY - TIMER5, - TIMER6, - TIMER7, - TIMER8, -#endif - }; - this->dev = devs[timerNum - 1]; + rcc_clk_id timerID = (rcc_clk_id)(RCC_TIMER1 + (timerNum - 1)); + this->dev = NULL; + noInterrupts(); // Hack to ensure we're the only ones using + // set_this_dev() and friends. TODO: use a lock. + this_id = timerID; + this_devp = &this->dev; + timer_foreach(set_this_dev); + interrupts(); + ASSERT(this->dev != NULL); } void HardwareTimer::pause(void) { @@ -92,6 +100,7 @@ void HardwareTimer::setCount(uint16 val) { timer_set_count(this->dev, min(val, ovf)); } +#define MAX_RELOAD ((1 << 16) - 1) uint16 HardwareTimer::setPeriod(uint32 microseconds) { // Not the best way to handle this edge case? if (!microseconds) { @@ -102,7 +111,7 @@ uint16 HardwareTimer::setPeriod(uint32 microseconds) { uint32 period_cyc = microseconds * CYCLES_PER_MICROSECOND; uint16 prescaler = (uint16)(period_cyc / MAX_RELOAD + 1); - uint16 overflow = (uint16)round(period_cyc / prescaler); + uint16 overflow = (uint16)((period_cyc + (prescaler / 2)) / prescaler); this->setPrescaleFactor(prescaler); this->setOverflow(overflow); return overflow; |