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cpu/efm32/timer: add support for LETIMER

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This commit is contained in:
Thomas Stilwell 2020-02-12 22:45:57 -06:00
parent 4dc82bce70
commit 651a3bf423
2 changed files with 162 additions and 39 deletions
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4
cpu/efm32/include/periph_cpu.h
View File

@ -348,12 +348,12 @@ typedef struct {
* @{
*/
typedef struct {
TIMER_TypeDef *dev; /**< Timer device used */
void *dev; /**< TIMER_TypeDef or LETIMER_TypeDef device used */
CMU_Clock_TypeDef cmu; /**< the device CMU channel */
} timer_dev_t;
typedef struct {
timer_dev_t prescaler; /**< the lower numbered neighboring timer */
timer_dev_t prescaler; /**< the lower neighboring timer (not initialized for LETIMER) */
timer_dev_t timer; /**< the higher numbered timer */
IRQn_Type irq; /**< number of the higher timer IRQ channel */
} timer_conf_t;

167
cpu/efm32/periph/timer.c
View File

@ -16,23 +16,31 @@
*
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
* @author Bas Stottelaar <basstottelaar@gmail.com>
* @author Thomas Stilwell <stilwellt@openlabs.co>
* @}
*/
#include "cpu.h"
#include "log.h"
#include "assert.h"
#include "periph/timer.h"
#include "periph_conf.h"
#include "em_cmu.h"
#include "em_timer.h"
#include "em_timer_utils.h"
#include "em_letimer.h"
/**
* @brief This timer implementation has three available channels
*/
#define CC_CHANNELS (3U)
/**
* @brief The LETIMER implementation has two available channels
*/
#define LE_CC_CHANNELS (2U)
/**
* @brief Timer state memory
*/
@ -47,23 +55,47 @@ static inline bool _is_wtimer(timer_t dev)
return ((uint32_t) timer_config[dev].timer.dev) >= WTIMER0_BASE;
#else
(void) dev;
return false;
#endif
}
int timer_init(tim_t dev, unsigned long freq, timer_cb_t callback, void *arg)
/**
* @brief Check whether dev is using a LETIMER device
*/
static inline bool _is_letimer(timer_t dev)
{
TIMER_TypeDef *pre, *tim;
/* test if given timer device is valid */
if (dev >= TIMER_NUMOF) {
return -1;
#if defined(LETIMER_COUNT) && LETIMER_COUNT > 0
return ((uint32_t) timer_config[dev].timer.dev) == LETIMER0_BASE;
#else
(void) dev;
return false;
#endif
}
/* save callback */
isr_ctx[dev].cb = callback;
isr_ctx[dev].arg = arg;
static void _letimer_init(tim_t dev, unsigned long freq)
{
(void) freq;
assert(freq == 32768);
LETIMER_TypeDef *tim = timer_config[dev].timer.dev;
/* enable clocks */
CMU_ClockEnable(timer_config[dev].timer.cmu, true);
CMU_ClockEnable(cmuClock_CORELE, true);
/* disable and clear interrupts */
LETIMER_IntDisable(tim, LETIMER_IEN_COMP0 | LETIMER_IEN_COMP1);
LETIMER_IntClear(tim, LETIMER_IFC_COMP0 | LETIMER_IFC_COMP1);
/* initialize timer without starting it yet */
LETIMER_Init_TypeDef letimerInit = LETIMER_INIT_DEFAULT;
letimerInit.enable = false;
LETIMER_Init(tim, &letimerInit);
}
static void _timer_init(tim_t dev, unsigned long freq)
{
TIMER_TypeDef *pre, *tim;
/* get timers */
pre = timer_config[dev].prescaler.dev;
@ -78,9 +110,9 @@ int timer_init(tim_t dev, unsigned long freq, timer_cb_t callback, void *arg)
TIMER_Init_TypeDef init_pre = TIMER_INIT_DEFAULT;
TIMER_Init_TypeDef init_tim = TIMER_INIT_DEFAULT;
init_pre.enable = false;
/* leave the prescaler enabled and toggle only the primary timer */
init_pre.enable = true;
init_pre.prescale = timerPrescale1;
init_tim.enable = false;
init_tim.clkSel = timerClkSelCascade;
@ -101,68 +133,159 @@ int timer_init(tim_t dev, unsigned long freq, timer_cb_t callback, void *arg)
/* enable interrupts for the channels */
TIMER_IntClear(tim, TIMER_IFC_CC0 | TIMER_IFC_CC1 | TIMER_IFC_CC2);
TIMER_IntEnable(tim, TIMER_IEN_CC0 | TIMER_IEN_CC1 | TIMER_IEN_CC2);
}
int timer_init(tim_t dev, unsigned long freq, timer_cb_t callback, void *arg)
{
/* test if given timer device is valid */
if (dev >= TIMER_NUMOF) {
return -1;
}
/* save callback */
isr_ctx[dev].cb = callback;
isr_ctx[dev].arg = arg;
if (_is_letimer(dev)) {
_letimer_init(dev, freq);
} else {
_timer_init(dev, freq);
}
NVIC_ClearPendingIRQ(timer_config[dev].irq);
NVIC_EnableIRQ(timer_config[dev].irq);
/* start the timers */
TIMER_Enable(tim, true);
TIMER_Enable(pre, true);
timer_start(dev);
return 0;
}
int timer_set_absolute(tim_t dev, int channel, unsigned int value)
{
TIMER_TypeDef *tim;
if (!_is_letimer(dev)) {
TIMER_TypeDef *tim = timer_config[dev].timer.dev;
if (channel < 0 || channel >= (int) CC_CHANNELS) {
return -1;
}
/* this accounts for some timer being 16-bit and others 32-bit */
if (value > TIMER_TopGet(timer_config[dev].timer.dev)) {
if (value > TIMER_TopGet(tim)) {
return -1;
}
tim = timer_config[dev].timer.dev;
tim->CC[channel].CCV = (uint32_t) value;
tim->CC[channel].CTRL = TIMER_CC_CTRL_MODE_OUTPUTCOMPARE;
}
else {
LETIMER_TypeDef *tim = timer_config[dev].timer.dev;
/* LETIMER is countdown only, so we invert the value */
value = 0xffff - value;
LETIMER_CompareSet(tim, channel, value);
switch (channel)
{
case 0:
LETIMER_IntClear(tim, LETIMER_IFC_COMP0);
LETIMER_IntEnable(tim, LETIMER_IEN_COMP0);
break;
case 1:
LETIMER_IntClear(tim, LETIMER_IFC_COMP1);
LETIMER_IntEnable(tim, LETIMER_IEN_COMP1);
break;
default:
return -2;
break;
}
}
return 0;
}
int timer_clear(tim_t dev, int channel)
{
timer_config[dev].timer.dev->CC[channel].CTRL = _TIMER_CC_CTRL_MODE_OFF;
if (!_is_letimer(dev)) {
TIMER_TypeDef *tim = timer_config[dev].timer.dev;
tim->CC[channel].CTRL = _TIMER_CC_CTRL_MODE_OFF;
}
else {
LETIMER_TypeDef *tim = timer_config[dev].timer.dev;
switch (channel)
{
case 0:
LETIMER_IntDisable(tim, LETIMER_IEN_COMP0);
LETIMER_IntClear(tim, LETIMER_IFC_COMP0);
break;
case 1:
LETIMER_IntDisable(tim, LETIMER_IEN_COMP1);
LETIMER_IntClear(tim, LETIMER_IFC_COMP1);
break;
default:
return -1;
}
}
return 0;
}
unsigned int timer_read(tim_t dev)
{
if (_is_letimer(dev)) {
/* LETIMER is countdown only, so we invert the value */
return (unsigned int) 0xffff
- LETIMER_CounterGet(timer_config[dev].timer.dev);
}
else {
return (unsigned int) TIMER_CounterGet(timer_config[dev].timer.dev);
}
}
void timer_stop(tim_t dev)
{
if (_is_letimer(dev)) {
LETIMER_Enable(timer_config[dev].timer.dev, false);
}
else {
TIMER_Enable(timer_config[dev].timer.dev, false);
}
}
void timer_start(tim_t dev)
{
if (_is_letimer(dev)) {
LETIMER_Enable(timer_config[dev].timer.dev, true);
}
else {
TIMER_Enable(timer_config[dev].timer.dev, true);
}
}
#ifdef TIMER_0_ISR
void TIMER_0_ISR(void)
{
TIMER_TypeDef *tim = timer_config[0].timer.dev;
tim_t dev = 0;
if (_is_letimer(dev)) {
LETIMER_TypeDef *tim = timer_config[dev].timer.dev;
for (int i = 0; i < (int) LE_CC_CHANNELS; i++) {
if (tim->IF & (LETIMER_IF_COMP0 << i))
{
LETIMER_IntDisable(tim, LETIMER_IEN_COMP0 << i);
LETIMER_IntClear(tim, LETIMER_IFC_COMP0 << i);
isr_ctx[dev].cb(isr_ctx[dev].arg, i);
}
}
}
else {
TIMER_TypeDef *tim = timer_config[dev].timer.dev;
for (int i = 0; i < (int) CC_CHANNELS; i++) {
if (tim->IF & (TIMER_IF_CC0 << i)) {
tim->CC[i].CTRL = _TIMER_CC_CTRL_MODE_OFF;
tim->IFC = (TIMER_IFC_CC0 << i);
isr_ctx[0].cb(isr_ctx[0].arg, i);
isr_ctx[dev].cb(isr_ctx[dev].arg, i);
}
}
}
cortexm_isr_end();