From 9c7ad68165bcd224c94ca6d8f172362cf8000d99 Mon Sep 17 00:00:00 2001 From: robert-hh Date: Thu, 23 Feb 2023 21:52:47 +0100 Subject: [PATCH] mimxrt/machine_pwm: Start PWM only if freq and duty are set. 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. --- ports/mimxrt/machine_pwm.c | 94 +++++++++++++++++++++----------------- 1 file changed, 52 insertions(+), 42 deletions(-) diff --git a/ports/mimxrt/machine_pwm.c b/ports/mimxrt/machine_pwm.c index c1d6bdf7a..b8b526ae0 100644 --- a/ports/mimxrt/machine_pwm.c +++ b/ports/mimxrt/machine_pwm.c @@ -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, "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); } }