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kinetis-tpm: Implement pulse_cycles directly instead of duty cycle

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When using low PWM frequency i.e 50Hz the resolution of pulse_cycles
got lost from converting pulse_cycles to duty cycle % and then back to
pulse_cycles again.

Furthermore TPM_UpdateChnlEdgeLevelSelect call would restart the pwm
constantly on a mcux_tpm_set_cycles call now only call
TPM_UpdateChnlEdgeLevelSelect when changing the polarity

Signed-off-by: Peter van der Perk <peter.vanderperk@nxp.com>
This commit is contained in:
Peter van der Perk 2025-03-31 16:39:46 +02:00 • committed by Benjamin Cabé
commit 886a99e736
1 changed files with 27 additions and 20 deletions
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47
drivers/pwm/pwm_mcux_tpm.c
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@ -55,29 +55,22 @@ static int mcux_tpm_set_cycles(const struct device *dev, uint32_t channel,
{
const struct mcux_tpm_config *config = dev->config;
struct mcux_tpm_data *data = dev->data;
uint8_t duty_cycle;
if (period_cycles == 0U) {
LOG_ERR("Channel can not be set to inactive level");
return -ENOTSUP;
}
if (channel >= config->channel_count) {
LOG_ERR("Invalid channel");
return -ENOTSUP;
}
duty_cycle = pulse_cycles * 100U / period_cycles;
data->channel[channel].dutyCyclePercent = duty_cycle;
if ((flags & PWM_POLARITY_INVERTED) == 0) {
data->channel[channel].level = kTPM_HighTrue;
} else {
data->channel[channel].level = kTPM_LowTrue;
if (period_cycles == 0 || period_cycles == TPM_MAX_COUNTER_VALUE(base)) {
return -ENOTSUP;
}
LOG_DBG("pulse_cycles=%d, period_cycles=%d, duty_cycle=%d, flags=%d",
pulse_cycles, period_cycles, duty_cycle, flags);
if ((TPM_MAX_COUNTER_VALUE(base) == 0xFFFFU) &&
(pulse_cycles > TPM_MAX_COUNTER_VALUE(base))) {
return -ENOTSUP;
}
LOG_DBG("pulse_cycles=%d, period_cycles=%d, flags=%d", pulse_cycles, period_cycles, flags);
if (period_cycles != data->period_cycles) {
uint32_t pwm_freq;
@ -106,6 +99,9 @@ static int mcux_tpm_set_cycles(const struct device *dev, uint32_t channel,
TPM_StopTimer(config->base);
/* Set counter back to zero */
config->base->CNT = 0;
status = TPM_SetupPwm(config->base, data->channel,
config->channel_count, config->mode,
pwm_freq, data->clock_freq);
@ -115,13 +111,24 @@ static int mcux_tpm_set_cycles(const struct device *dev, uint32_t channel,
return -ENOTSUP;
}
TPM_StartTimer(config->base, config->tpm_clock_source);
} else {
TPM_UpdateChnlEdgeLevelSelect(config->base, channel,
data->channel[channel].level);
TPM_UpdatePwmDutycycle(config->base, channel, config->mode,
duty_cycle);
}
if ((flags & PWM_POLARITY_INVERTED) == 0 &&
data->channel[channel].level != kTPM_HighTrue) {
data->channel[channel].level = kTPM_HighTrue;
TPM_UpdateChnlEdgeLevelSelect(config->base, channel, kTPM_HighTrue);
} else if ((flags & PWM_POLARITY_INVERTED) != 0 &&
data->channel[channel].level != kTPM_LowTrue) {
data->channel[channel].level = kTPM_LowTrue;
TPM_UpdateChnlEdgeLevelSelect(config->base, channel, kTPM_LowTrue);
}
if (pulse_cycles == period_cycles) {
pulse_cycles = period_cycles + 1U;
}
config->base->CONTROLS[channel].CnV = pulse_cycles;
return 0;
}