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mimxrt/machine_pwm: Start PWM only if freq and duty are set.

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And also fix/improve the following:
- Simplify the duty handling a little bit.
- Allow duty_u16(65536), which sets the output high.
- Rename machine_pwm_start() to mp_machine_pwm_start(), in preparation for
  a possible start/stop method pair.
This commit is contained in:
robert-hh 2023-02-23 21:52:47 +01:00 committed by Damien George
parent 0264465585
commit 9c7ad68165
1 changed files with 52 additions and 42 deletions
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94
ports/mimxrt/machine_pwm.c
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@ -39,6 +39,7 @@
#define PWM_CHANNEL1 (1)
#define PWM_CHANNEL2 (2)
#define VALUE_NOT_SET (-1)
typedef struct _machine_pwm_obj_t {
mp_obj_base_t base;
@ -51,10 +52,10 @@ typedef struct _machine_pwm_obj_t {
uint8_t channel2;
uint8_t invert;
bool sync;
uint32_t freq;
int32_t freq;
int16_t prescale;
uint16_t duty_u16;
uint32_t duty_ns;
int32_t duty_u16;
int32_t duty_ns;
uint16_t center;
uint32_t deadtime;
bool output_enable_1;
@ -68,7 +69,7 @@ static char *ERRMSG_FREQ = "PWM frequency too low";
static char *ERRMSG_INIT = "PWM set-up failed";
static char *ERRMSG_VALUE = "value larger than period";
STATIC void machine_pwm_start(machine_pwm_obj_t *self);
STATIC void mp_machine_pwm_start(machine_pwm_obj_t *self);
STATIC void mp_machine_pwm_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
machine_pwm_obj_t *self = MP_OBJ_TO_PTR(self_in);
@ -79,36 +80,40 @@ STATIC void mp_machine_pwm_print(const mp_print_t *print, mp_obj_t self_in, mp_p
} else {
mp_printf(print, "channel=%c", channel_char[self->channel1]);
}
if (self->duty_ns != 0) {
mp_printf(print, " duty_ns=%u", self->duty_ns);
if (self->duty_ns != VALUE_NOT_SET) {
mp_printf(print, " duty_ns=%d", self->duty_ns);
} else {
mp_printf(print, " duty_u16=%u", self->duty_u16);
mp_printf(print, " duty_u16=%d", self->duty_u16);
}
mp_printf(print, " freq=%u center=%u, deadtime=%u, sync=%u>",
mp_printf(print, " freq=%d center=%u, deadtime=%u, sync=%u>",
self->freq, self->center, self->deadtime, self->sync);
#ifdef FSL_FEATURE_SOC_TMR_COUNT
} else {
mp_printf(print, "<QTMR_PWM module=%u channel=%u freq1=%u ",
mp_printf(print, "<QTMR_PWM module=%u channel=%u freq=%u ",
self->module, self->channel1, self->freq);
if (self->duty_ns != 0) {
mp_printf(print, "duty_ns=%u>", self->duty_ns);
if (self->duty_ns == VALUE_NOT_SET) {
mp_printf(print, "duty_ns=%d>", self->duty_ns);
} else {
mp_printf(print, "duty_u16=%u>", self->duty_u16);
mp_printf(print, "duty_u16=%d>", self->duty_u16);
}
#endif
}
}
// Utility functions for decoding and convertings
// Utility functions for decoding and converting
//
STATIC uint32_t duty_ns_to_duty_u16(uint32_t freq, uint32_t duty_ns) {
uint64_t duty = (uint64_t)duty_ns * freq * PWM_FULL_SCALE / 1000000000ULL;
if (duty >= PWM_FULL_SCALE) {
if (duty > PWM_FULL_SCALE) {
mp_raise_ValueError(MP_ERROR_TEXT(ERRMSG_VALUE));
}
return (uint32_t)duty;
}
STATIC uint32_t duty_u16_to_duty_ns(machine_pwm_obj_t *self) {
return 1000000000ULL * (uint64_t)self->duty_u16 / self->freq / PWM_FULL_SCALE;
}
STATIC uint8_t module_decode(char channel) {
switch (channel) {
case '0':
@ -340,15 +345,20 @@ STATIC void configure_pwm(machine_pwm_obj_t *self) {
set_frequency = false;
}
if (self->duty_ns != 0) {
self->duty_u16 = duty_ns_to_duty_u16(self->freq, self->duty_ns);
}
if (self->is_flexpwm) {
configure_flexpwm(self);
#ifdef FSL_FEATURE_SOC_TMR_COUNT
} else {
configure_qtmr(self);
#endif
// Enable the PWM only if both freq and duty value are set
if (self->freq != VALUE_NOT_SET && (self->duty_u16 != VALUE_NOT_SET || self->duty_ns != VALUE_NOT_SET)) {
if (self->duty_ns != VALUE_NOT_SET) {
self->duty_u16 = duty_ns_to_duty_u16(self->freq, self->duty_ns);
} else {
self->duty_ns = duty_u16_to_duty_ns(self);
}
if (self->is_flexpwm) {
configure_flexpwm(self);
#ifdef FSL_FEATURE_SOC_TMR_COUNT
} else {
configure_qtmr(self);
#endif
}
}
}
@ -359,9 +369,9 @@ STATIC void mp_machine_pwm_init_helper(machine_pwm_obj_t *self,
enum { ARG_freq, ARG_duty_u16, ARG_duty_ns, ARG_center, ARG_align,
ARG_invert, ARG_sync, ARG_xor, ARG_deadtime };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_freq, MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_duty_u16, MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_duty_ns, MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_freq, MP_ARG_INT, {.u_int = VALUE_NOT_SET} },
{ MP_QSTR_duty_u16, MP_ARG_INT, {.u_int = VALUE_NOT_SET} },
{ MP_QSTR_duty_ns, MP_ARG_INT, {.u_int = VALUE_NOT_SET} },
{ MP_QSTR_center, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_align, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1}},
{ MP_QSTR_invert, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1}},
@ -380,24 +390,24 @@ STATIC void mp_machine_pwm_init_helper(machine_pwm_obj_t *self,
}
// Set duty_u16 cycle?
uint32_t duty = args[ARG_duty_u16].u_int;
if (duty != 0) {
if (duty >= PWM_FULL_SCALE) {
int32_t duty = args[ARG_duty_u16].u_int;
if (duty >= 0) {
if (duty > PWM_FULL_SCALE) {
mp_raise_ValueError(MP_ERROR_TEXT(ERRMSG_VALUE));
}
self->duty_u16 = duty;
self->duty_ns = 0;
self->duty_ns = VALUE_NOT_SET;
}
// Set duty_ns value?
duty = args[ARG_duty_ns].u_int;
if (duty != 0) {
if (duty >= 0) {
self->duty_ns = duty;
self->duty_u16 = duty_ns_to_duty_u16(self->freq, self->duty_ns);
self->duty_u16 = VALUE_NOT_SET;
}
// Set center value?
int32_t center = args[ARG_center].u_int;
if (center >= 0) {
if (center >= PWM_FULL_SCALE) {
if (center > PWM_FULL_SCALE) {
mp_raise_ValueError(MP_ERROR_TEXT(ERRMSG_VALUE));
}
self->center = center;
@ -432,7 +442,7 @@ STATIC void mp_machine_pwm_init_helper(machine_pwm_obj_t *self,
configure_pwm(self);
self->is_init = true;
} else {
machine_pwm_start(self);
mp_machine_pwm_start(self);
}
}
@ -512,10 +522,10 @@ STATIC mp_obj_t mp_machine_pwm_make_new(const mp_obj_type_t *type, size_t n_args
self->submodule = submodule1;
self->channel1 = channel1;
self->invert = 0;
self->freq = 1000;
self->freq = VALUE_NOT_SET;
self->prescale = -1;
self->duty_u16 = 32768;
self->duty_ns = 0;
self->duty_u16 = VALUE_NOT_SET;
self->duty_ns = VALUE_NOT_SET;
self->center = 32768;
self->output_enable_1 = is_board_pin(pin1);
self->sync = false;
@ -571,7 +581,7 @@ void machine_pwm_deinit_all(void) {
#endif
}
STATIC void machine_pwm_start(machine_pwm_obj_t *self) {
STATIC void mp_machine_pwm_start(machine_pwm_obj_t *self) {
if (self->is_flexpwm) {
PWM_StartTimer(self->instance, 1 << self->submodule);
#ifdef FSL_FEATURE_SOC_TMR_COUNT
@ -606,23 +616,23 @@ mp_obj_t mp_machine_pwm_duty_get_u16(machine_pwm_obj_t *self) {
void mp_machine_pwm_duty_set_u16(machine_pwm_obj_t *self, mp_int_t duty) {
if (duty >= 0) {
if (duty >= PWM_FULL_SCALE) {
if (duty > PWM_FULL_SCALE) {
mp_raise_ValueError(MP_ERROR_TEXT(ERRMSG_VALUE));
}
self->duty_u16 = duty;
self->duty_ns = 0;
self->duty_ns = VALUE_NOT_SET;
configure_pwm(self);
}
}
mp_obj_t mp_machine_pwm_duty_get_ns(machine_pwm_obj_t *self) {
return MP_OBJ_NEW_SMALL_INT(1000000000ULL / self->freq * self->duty_u16 / PWM_FULL_SCALE);
return MP_OBJ_NEW_SMALL_INT(self->duty_ns);
}
void mp_machine_pwm_duty_set_ns(machine_pwm_obj_t *self, mp_int_t duty) {
if (duty >= 0) {
self->duty_ns = duty;
self->duty_u16 = duty_ns_to_duty_u16(self->freq, self->duty_ns);
self->duty_u16 = VALUE_NOT_SET;
configure_pwm(self);
}
}