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ports/esp32/machine_pwm: Add support for all PWM timers and modes. #3608

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ports/esp32/machine_pwm: Add support for all PWM timers and modes. #3608

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125 changes: 78 additions & 47 deletions ports/esp32/machine_pwm.c
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Original file line number Diff line number Diff line change
Expand Up @@ -35,56 +35,52 @@
// Forward dec'l
extern const mp_obj_type_t machine_pwm_type;


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Please don't add blank lines when not necessary.

typedef struct _esp32_pwm_obj_t {
mp_obj_base_t base;
gpio_num_t pin;
uint8_t active;
uint8_t channel;
uint8_t timer;
uint8_t mode;
} esp32_pwm_obj_t;

// Number of available timers
#define LEDC_TIMER_MAX 4

// Which channel has which GPIO pin assigned?
// (-1 if not assigned)
STATIC int chan_gpio[LEDC_CHANNEL_MAX];

// Params for PW operation
// 5khz
#define PWFREQ (5000)
// High speed mode
#define PWMODE (LEDC_HIGH_SPEED_MODE)
// 10-bit resolution (compatible with esp8266 PWM)
#define PWRES (LEDC_TIMER_10_BIT)
// Timer 1
#define PWTIMER (LEDC_TIMER_1)

// Config of timer upon which we run all PWM'ed GPIO pins
STATIC bool pwm_inited = false;
STATIC ledc_timer_config_t timer_cfg = {
.bit_num = PWRES,
.freq_hz = PWFREQ,
.speed_mode = PWMODE,
.timer_num = PWTIMER
};

STATIC void pwm_init(void) {

// Initial condition: no channels assigned
for (int x = 0; x < LEDC_CHANNEL_MAX; ++x) {
chan_gpio[x] = -1;
}

// Init with default timer params
ledc_timer_config(&timer_cfg);
}

STATIC int set_freq(int newval) {
int oval = timer_cfg.freq_hz;

timer_cfg.freq_hz = newval;
if (ledc_timer_config(&timer_cfg) != ESP_OK) {
timer_cfg.freq_hz = oval;
return 0;
// prepare all timers
ledc_timer_config_t timer_cfg = {
.bit_num = PWRES,
.freq_hz = PWFREQ,
.speed_mode = LEDC_LOW_SPEED_MODE,
.timer_num = 0,
};
for (int mode = 0; mode < LEDC_SPEED_MODE_MAX; ++mode) {
for (int idx = 0; idx < LEDC_TIMER_MAX; ++idx) {
timer_cfg.timer_num = idx;
timer_cfg.speed_mode = mode;
ledc_timer_config(&timer_cfg);
}
}
return 1;
}

/******************************************************************************/
Expand All @@ -93,20 +89,23 @@ STATIC int set_freq(int newval) {

STATIC void esp32_pwm_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
esp32_pwm_obj_t *self = MP_OBJ_TO_PTR(self_in);
mp_printf(print, "PWM(%u", self->pin);
mp_printf(print, "PWM(%u, timer=%u, speed_mode=%u", self->pin, self->timer, self->mode);
if (self->active) {
mp_printf(print, ", freq=%u, duty=%u", timer_cfg.freq_hz,
ledc_get_duty(PWMODE, self->channel));
mp_printf(print, ", freq=%u, duty=%u",
ledc_get_freq(self->mode, self->timer),
ledc_get_duty(self->mode, self->channel));
}
mp_printf(print, ")");
}

STATIC void esp32_pwm_init_helper(esp32_pwm_obj_t *self,
size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
enum { ARG_freq, ARG_duty };
enum { ARG_freq, ARG_duty, ARG_timer, ARG_mode };
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_freq, MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_duty, MP_ARG_INT, {.u_int = -1} },
{ MP_QSTR_timer, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_speed_mode, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = LEDC_HIGH_SPEED_MODE} },
};
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args, pos_args, kw_args,
Expand All @@ -133,16 +132,31 @@ STATIC void esp32_pwm_init_helper(esp32_pwm_obj_t *self,
}
self->channel = channel;

// set timer
if (0 <= args[ARG_timer].u_int && args[ARG_timer].u_int <= 3) {
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Shouldn't the upper bound be < LEDC_TIMER_MAX?

self->timer = args[ARG_timer].u_int;
} else {
mp_raise_ValueError("invalid timer");
}

// set speed mode
if (0 <= args[ARG_mode].u_int && args[ARG_mode].u_int <= LEDC_SPEED_MODE_MAX) {
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I think the upper bound here should be < LEDC_SPEED_MODE_MAX (note < not <=).

self->mode = args[ARG_mode].u_int;
} else {
mp_raise_ValueError("invalid speed_mode");
}

// New PWM assignment
self->active = 1;
if (chan_gpio[channel] == -1) {
// configure channel
ledc_channel_config_t cfg = {
.channel = channel,
.duty = (1 << PWRES) / 2,
.gpio_num = self->pin,
.intr_type = LEDC_INTR_DISABLE,
.speed_mode = PWMODE,
.timer_sel = PWTIMER,
.speed_mode = self->mode,
.timer_sel = self->timer,
};
if (ledc_channel_config(&cfg) != ESP_OK) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
Expand All @@ -152,22 +166,23 @@ STATIC void esp32_pwm_init_helper(esp32_pwm_obj_t *self,
}

// Maybe change PWM timer
int tval = args[ARG_freq].u_int;
if (tval != -1) {
if (tval != timer_cfg.freq_hz) {
if (!set_freq(tval)) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
"Bad frequency %d", tval));
}
}
int fval = args[ARG_freq].u_int;
if (fval != -1 && ledc_set_freq(self->mode, self->timer, fval) != ESP_OK) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
"Bad frequency %d", fval));
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Please use lower-case at the start of error messages, for consistency with the rest of the code.

}

// Set duty cycle?
int dval = args[ARG_duty].u_int;
if (dval != -1) {
dval &= ((1 << PWRES)-1);
ledc_set_duty(PWMODE, channel, dval);
ledc_update_duty(PWMODE, channel);
ledc_set_duty(self->mode, channel, dval);
ledc_update_duty(self->mode, channel);
}

// Reset the timer if low speed
if (self->mode == LEDC_LOW_SPEED_MODE) {
ledc_timer_rst(self->mode, self->timer);
}
}

Expand Down Expand Up @@ -210,28 +225,42 @@ STATIC mp_obj_t esp32_pwm_deinit(mp_obj_t self_in) {

// Valid channel?
if ((chan >= 0) && (chan < LEDC_CHANNEL_MAX)) {
// Mark it unused, and tell the hardware to stop routing
// Mark it unused, and tell the hardware to stop
chan_gpio[chan] = -1;
ledc_stop(PWMODE, chan, 0);
ledc_stop(self->mode, chan, 0);
self->active = 0;
self->channel = -1;
// Disable ledc signal for the pin
if (self->mode == LEDC_LOW_SPEED_MODE) {
gpio_matrix_out(self->pin, LEDC_LS_SIG_OUT0_IDX + self->channel, false, true);
} else {
gpio_matrix_out(self->pin, LEDC_HS_SIG_OUT0_IDX + self->channel, false, true);
}
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(esp32_pwm_deinit_obj, esp32_pwm_deinit);

STATIC mp_obj_t esp32_pwm_freq(size_t n_args, const mp_obj_t *args) {
esp32_pwm_obj_t *self = MP_OBJ_TO_PTR(args[0]);

if (n_args == 1) {
// get
return MP_OBJ_NEW_SMALL_INT(timer_cfg.freq_hz);
return MP_OBJ_NEW_SMALL_INT(ledc_get_freq(self->mode, self->timer));
}

// set
int tval = mp_obj_get_int(args[1]);
if (!set_freq(tval)) {
if (tval <= 0 || ledc_set_freq(self->mode, self->timer, tval) != ESP_OK) {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError,
"Bad frequency %d", tval));
"bad frequency %d", tval));
}

// Reset the timer if low speed
if (self->mode == LEDC_LOW_SPEED_MODE) {
ledc_timer_rst(self->mode, self->timer);
}

return mp_const_none;
}

Expand All @@ -243,15 +272,15 @@ STATIC mp_obj_t esp32_pwm_duty(size_t n_args, const mp_obj_t *args) {

if (n_args == 1) {
// get
duty = ledc_get_duty(PWMODE, self->channel);
duty = ledc_get_duty(self->mode, self->channel);
return MP_OBJ_NEW_SMALL_INT(duty);
}

// set
duty = mp_obj_get_int(args[1]);
duty &= ((1 << PWRES)-1);
ledc_set_duty(PWMODE, self->channel, duty);
ledc_update_duty(PWMODE, self->channel);
ledc_set_duty(self->mode, self->channel, duty);
ledc_update_duty(self->mode, self->channel);

return mp_const_none;
}
Expand All @@ -263,6 +292,8 @@ STATIC const mp_rom_map_elem_t esp32_pwm_locals_dict_table[] = {
{ MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&esp32_pwm_deinit_obj) },
{ MP_ROM_QSTR(MP_QSTR_freq), MP_ROM_PTR(&esp32_pwm_freq_obj) },
{ MP_ROM_QSTR(MP_QSTR_duty), MP_ROM_PTR(&esp32_pwm_duty_obj) },
{ MP_ROM_QSTR(MP_QSTR_HIGH_SPEED_MODE), MP_ROM_INT(LEDC_HIGH_SPEED_MODE) },
{ MP_ROM_QSTR(MP_QSTR_LOW_SPEED_MODE), MP_ROM_INT(LEDC_LOW_SPEED_MODE) },
};

STATIC MP_DEFINE_CONST_DICT(esp32_pwm_locals_dict,
Expand Down