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atmel-samd: Fix PWMOut duty_cycle when used with TCC peripherals. 

Fixes #148. Fixes #151
This commit is contained in:
Scott Shawcroft 2017-06-06 13:16:34 -07:00
parent 9345562cc8
commit a884acc7f6
2 changed files with 18 additions and 12 deletions
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29
atmel-samd/common-hal/pulseio/PWMOut.c
View File

@ -3,6 +3,7 @@
* *
* The MIT License (MIT) * The MIT License (MIT)
* *
* Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
* Copyright (c) 2016 Damien P. George * Copyright (c) 2016 Damien P. George
* *
* Permission is hereby granted, free of charge, to any person obtaining a copy * Permission is hereby granted, free of charge, to any person obtaining a copy
@ -104,10 +105,10 @@ void common_hal_pulseio_pwmout_construct(pulseio_pwmout_obj_t* self,
const pin_timer_t* t = NULL; const pin_timer_t* t = NULL;
uint8_t index = 0; uint8_t index = 0;
if (!variable_frequency && if (!variable_frequency &&
primary_timer_index != 0xff && primary_timer_index != 0xff &&
target_timer_frequencies[primary_timer_index] == frequency && target_timer_frequencies[primary_timer_index] == frequency &&
pin->primary_timer.tcc->CTRLA.bit.ENABLE == 1 && pin->primary_timer.tcc->CTRLA.bit.ENABLE == 1 &&
channel_ok(&pin->primary_timer, primary_timer_index)) { channel_ok(&pin->primary_timer, primary_timer_index)) {
t = &pin->primary_timer; t = &pin->primary_timer;
index = primary_timer_index; index = primary_timer_index;
} else if (!variable_frequency && } else if (!variable_frequency &&
@ -153,6 +154,7 @@ void common_hal_pulseio_pwmout_construct(pulseio_pwmout_obj_t* self,
break; break;
} }
} }
self->period = top;
if (t->is_tc) { if (t->is_tc) {
struct tc_config config_tc; struct tc_config config_tc;
tc_get_config_defaults(&config_tc); tc_get_config_defaults(&config_tc);
@ -228,12 +230,10 @@ extern void common_hal_pulseio_pwmout_deinit(pulseio_pwmout_obj_t* self) {
extern void common_hal_pulseio_pwmout_set_duty_cycle(pulseio_pwmout_obj_t* self, uint16_t duty) { extern void common_hal_pulseio_pwmout_set_duty_cycle(pulseio_pwmout_obj_t* self, uint16_t duty) {
const pin_timer_t* t = self->timer; const pin_timer_t* t = self->timer;
if (t->is_tc) { if (t->is_tc) {
uint32_t top = ((uint32_t) t->tc->COUNT16.CC[0].reg + 1); uint16_t adjusted_duty = self->period * duty / 0xffff;
uint16_t adjusted_duty = top * duty / 0xffff;
tc_set_compare_value(&self->tc_instance, t->channel, adjusted_duty); tc_set_compare_value(&self->tc_instance, t->channel, adjusted_duty);
} else { } else {
uint32_t top = t->tcc->PER.reg + 1; uint32_t adjusted_duty = ((uint64_t) self->period) * duty / 0xffff;
uint32_t adjusted_duty = ((uint64_t) top) * duty / 0xffff;
tcc_set_compare_value(&self->tcc_instance, t->channel, adjusted_duty); tcc_set_compare_value(&self->tcc_instance, t->channel, adjusted_duty);
} }
} }
@ -241,21 +241,22 @@ extern void common_hal_pulseio_pwmout_set_duty_cycle(pulseio_pwmout_obj_t* self,
uint16_t common_hal_pulseio_pwmout_get_duty_cycle(pulseio_pwmout_obj_t* self) { uint16_t common_hal_pulseio_pwmout_get_duty_cycle(pulseio_pwmout_obj_t* self) {
const pin_timer_t* t = self->timer; const pin_timer_t* t = self->timer;
if (t->is_tc) { if (t->is_tc) {
uint16_t top = t->tc->COUNT16.CC[0].reg;
while (tc_is_syncing(&self->tc_instance)) { while (tc_is_syncing(&self->tc_instance)) {
/* Wait for sync */ /* Wait for sync */
} }
uint16_t cv = t->tc->COUNT16.CC[t->channel].reg; uint16_t cv = t->tc->COUNT16.CC[t->channel].reg;
return cv * 0xffff / top; return cv * 0xffff / self->period;
} else { } else {
uint32_t top = t->tcc->PER.reg;
uint32_t cv = 0; uint32_t cv = 0;
if ((t->tcc->STATUS.vec.CCBV & (1 << t->channel)) != 0) { if ((t->tcc->STATUS.vec.CCBV & (1 << t->channel)) != 0) {
cv = t->tcc->CCB[t->channel].reg; cv = t->tcc->CCB[t->channel].reg;
} else { } else {
cv = t->tcc->CC[t->channel].reg; cv = t->tcc->CC[t->channel].reg;
} }
return cv * 0xffff / top;
uint32_t duty_cycle = ((uint64_t) cv) * 0xffff / self->period;
return duty_cycle;
} }
} }
@ -299,6 +300,7 @@ void common_hal_pulseio_pwmout_set_frequency(pulseio_pwmout_obj_t* self,
tcc_enable(&self->tcc_instance); tcc_enable(&self->tcc_instance);
} }
} }
self->period = new_top;
if (t->is_tc) { if (t->is_tc) {
while (tc_is_syncing(&self->tc_instance)) { while (tc_is_syncing(&self->tc_instance)) {
/* Wait for sync */ /* Wait for sync */
@ -321,6 +323,9 @@ uint32_t common_hal_pulseio_pwmout_get_frequency(pulseio_pwmout_obj_t* self) {
divisor = t->tc->COUNT16.CTRLA.bit.PRESCALER; divisor = t->tc->COUNT16.CTRLA.bit.PRESCALER;
} else { } else {
top = t->tcc->PER.reg; top = t->tcc->PER.reg;
if (t->tcc->STATUS.bit.PERBV) {
top = t->tcc->PERB.reg;
}
divisor = t->tcc->CTRLA.bit.PRESCALER; divisor = t->tcc->CTRLA.bit.PRESCALER;
} }
return (system_clock / prescaler[divisor]) / (top + 1); return (system_clock / prescaler[divisor]) / (top + 1);

1
atmel-samd/common-hal/pulseio/PWMOut.h
View File

@ -38,6 +38,7 @@ typedef struct {
const mcu_pin_obj_t *pin; const mcu_pin_obj_t *pin;
const pin_timer_t* timer; const pin_timer_t* timer;
bool variable_frequency; bool variable_frequency;
uint32_t period;
union { union {
struct tc_module tc_instance; struct tc_module tc_instance;
struct tcc_module tcc_instance; struct tcc_module tcc_instance;