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pwmout - LPC11XX_11CXX - add read methods for period and pulsewidth

pull/13492/head
talorion 2020-08-25 23:45:15 +02:00 committed by Gregor Mayramhof
parent fabd906534
commit 7270f296d3
1 changed files with 51 additions and 32 deletions
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83
targets/TARGET_NXP/TARGET_LPC11XX_11CXX/pwmout_api.c
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@ -28,17 +28,17 @@
*/
static const PinMap PinMap_PWM[] = {
/* CT16B0 */
{P0_8 , PWM_1, 0x02}, /* MR0 */
{P0_9 , PWM_2, 0x02}, /* MR1 */
{P0_8, PWM_1, 0x02}, /* MR0 */
{P0_9, PWM_2, 0x02}, /* MR1 */
/* CT16B1 */
{P1_9 , PWM_3, 0x01}, /* MR0 */
{P1_9, PWM_3, 0x01}, /* MR0 */
{P1_10, PWM_4, 0x02}, /* MR1 */
/* CT32B0 */
{P0_1 , PWM_5, 0x02}, /* MR2 */
{P0_1, PWM_5, 0x02}, /* MR2 */
{NC , NC ,0x00}
{NC, NC, 0x00}
};
typedef struct {
@ -61,49 +61,52 @@ static LPC_TMR_TypeDef *Timers[3] = {
LPC_TMR32B0
};
void pwmout_init(pwmout_t* obj, PinName pin) {
void pwmout_init(pwmout_t *obj, PinName pin)
{
// determine the channel
PWMName pwm = (PWMName)pinmap_peripheral(pin, PinMap_PWM);
MBED_ASSERT(pwm != (PWMName)NC);
obj->pwm = pwm;
// Timer registers
timer_mr tid = pwm_timer_map[pwm];
LPC_TMR_TypeDef *timer = Timers[tid.timer];
// Disable timer
timer->TCR = 0;
// Power the correspondent timer
LPC_SYSCON->SYSAHBCLKCTRL |= 1 << (tid.timer + 7);
/* Enable PWM function */
timer->PWMC = (1 << 3)|(1 << 2)|(1 << 1)|(1 << 0);
timer->PWMC = (1 << 3) | (1 << 2) | (1 << 1) | (1 << 0);
/* Reset Functionality on MR3 controlling the PWM period */
timer->MCR = 1 << 10;
if (timer == LPC_TMR16B0 || timer == LPC_TMR16B1) {
/* Set 16-bit timer prescaler to avoid timer expire for default 20ms */
/* This can be also modified by user application, but the prescaler value */
/* might be trade-off to timer accuracy */
/* Set 16-bit timer prescaler to avoid timer expire for default 20ms */
/* This can be also modified by user application, but the prescaler value */
/* might be trade-off to timer accuracy */
timer->PR = 30;
}
// default to 20ms: standard for servos, and fine for e.g. brightness control
pwmout_period_ms(obj, 20);
pwmout_write (obj, 0);
pwmout_write(obj, 0);
// Wire pinout
pinmap_pinout(pin, PinMap_PWM);
}
void pwmout_free(pwmout_t* obj) {
void pwmout_free(pwmout_t *obj)
{
// [TODO]
}
void pwmout_write(pwmout_t* obj, float value) {
void pwmout_write(pwmout_t *obj, float value)
{
if (value < 0.0f) {
value = 0.0;
} else if (value > 1.0f) {
@ -123,10 +126,11 @@ void pwmout_write(pwmout_t* obj, float value) {
timer->TCR = TCR_CNT_EN;
}
float pwmout_read(pwmout_t* obj) {
float pwmout_read(pwmout_t *obj)
{
timer_mr tid = pwm_timer_map[obj->pwm];
LPC_TMR_TypeDef *timer = Timers[tid.timer];
float v = (float)(timer->MR3 - timer->MR[tid.mr]) / (float)(timer->MR3);
if (timer->MR[tid.mr] > timer->MR3) {
v = 0.0f;
@ -134,19 +138,22 @@ float pwmout_read(pwmout_t* obj) {
return (v > 1.0f) ? (1.0f) : (v);
}
void pwmout_period(pwmout_t* obj, float seconds) {
void pwmout_period(pwmout_t *obj, float seconds)
{
pwmout_period_us(obj, seconds * 1000000.0f);
}
void pwmout_period_ms(pwmout_t* obj, int ms) {
void pwmout_period_ms(pwmout_t *obj, int ms)
{
pwmout_period_us(obj, ms * 1000);
}
// Set the PWM period, keeping the duty cycle the same.
void pwmout_period_us(pwmout_t* obj, int us) {
void pwmout_period_us(pwmout_t *obj, int us)
{
int i = 0;
uint32_t period_ticks;
timer_mr tid = pwm_timer_map[obj->pwm];
LPC_TMR_TypeDef *timer = Timers[tid.timer];
uint32_t old_period_ticks = timer->MR3;
@ -154,10 +161,10 @@ void pwmout_period_us(pwmout_t* obj, int us) {
timer->TCR = TCR_RESET;
timer->MR3 = period_ticks;
// Scale the pulse width to preserve the duty ratio
if (old_period_ticks > 0) {
for (i=0; i<3; i++) {
for (i = 0; i < 3; i++) {
uint32_t t_off = period_ticks - (uint32_t)(((uint64_t)timer->MR[i] * (uint64_t)period_ticks) / (uint64_t)old_period_ticks);
timer->MR[i] = t_off;
}
@ -165,19 +172,27 @@ void pwmout_period_us(pwmout_t* obj, int us) {
timer->TCR = TCR_CNT_EN;
}
void pwmout_pulsewidth(pwmout_t* obj, float seconds) {
int pwmout_read_period_us(pwmout_t *obj)
{
return (timer->MR3);
}
void pwmout_pulsewidth(pwmout_t *obj, float seconds)
{
pwmout_pulsewidth_us(obj, seconds * 1000000.0f);
}
void pwmout_pulsewidth_ms(pwmout_t* obj, int ms) {
void pwmout_pulsewidth_ms(pwmout_t *obj, int ms)
{
pwmout_pulsewidth_us(obj, ms * 1000);
}
void pwmout_pulsewidth_us(pwmout_t* obj, int us) {
void pwmout_pulsewidth_us(pwmout_t *obj, int us)
{
timer_mr tid = pwm_timer_map[obj->pwm];
LPC_TMR_TypeDef *timer = Timers[tid.timer];
uint32_t t_on = (uint32_t)((((uint64_t)SystemCoreClock * (uint64_t)us) / (uint64_t)1000000) / (timer->PR + 1));
timer->TCR = TCR_RESET;
if (t_on > timer->MR3) {
pwmout_period_us(obj, us);
@ -187,6 +202,10 @@ void pwmout_pulsewidth_us(pwmout_t* obj, int us) {
timer->TCR = TCR_CNT_EN;
}
int pwmout_read_pulsewidth_us(pwmout_t *obj {
return (timer->MR3 - timer->MR[tid.mr]);
}
const PinMap *pwmout_pinmap()
{
return PinMap_PWM;