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esp32/machine_pwm: Always set the duty cycle when setting the frequency.

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If setting the frequency to a value used already by an existing timer, this
timer will be used.  But still, the duty cycle for that channel may have to
be changed.

Fixes issues #8306 and #8345.
This commit is contained in:
robert-hh 2022-02-27 15:22:21 +01:00 committed by Damien George
parent 665f0e2a68
commit 55a0125a15
1 changed files with 35 additions and 23 deletions
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58
ports/esp32/machine_pwm.c Executable file → Normal file
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@ -74,7 +74,8 @@ STATIC ledc_timer_config_t timers[PWM_TIMER_MAX];
// Params for PWM operation
// 5khz is default frequency
#define PWM_FREQ (5000)
// default 10-bit resolution (compatible with esp8266 PWM)
// 10-bit resolution (compatible with esp8266 PWM)
#define PWM_RES_10_BIT (LEDC_TIMER_10_BIT)
// Maximum duty value on 10-bit resolution
@ -84,15 +85,17 @@ STATIC ledc_timer_config_t timers[PWM_TIMER_MAX];
// duty_u16() and duty_ns() use 16-bit resolution or less
// Possible highest resolution in device
#if CONFIG_IDF_TARGET_ESP32
#define HIGHEST_PWM_RES (LEDC_TIMER_16_BIT) // 20 bit for ESP32, but 16 bit is used
#if (LEDC_TIMER_BIT_MAX - 1) < LEDC_TIMER_16_BIT
#define HIGHEST_PWM_RES (LEDC_TIMER_BIT_MAX - 1)
#else
#define HIGHEST_PWM_RES (LEDC_TIMER_BIT_MAX - 1) // 14 bit is used
#define HIGHEST_PWM_RES (LEDC_TIMER_16_BIT) // 20 bit for ESP32, but 16 bit is used
#endif
// Duty resolution of user interface in `duty_u16()` and `duty_u16` parameter in constructor/initializer
#define UI_RES_16_BIT (16)
// Maximum duty value on highest user interface resolution
#define UI_MAX_DUTY ((1 << UI_RES_16_BIT) - 1)
// How much to shift from the HIGHEST_PWM_RES duty resolution to the user interface duty resolution UI_RES_16_BIT
#define UI_RES_SHIFT (UI_RES_16_BIT - HIGHEST_PWM_RES) // 0 for ESP32, 2 for S2, S3, C3
// If the PWM frequency is less than EMPIRIC_FREQ, then LEDC_REF_CLK_HZ(1 MHz) source is used, else LEDC_APB_CLK_HZ(80 MHz) source is used
#define EMPIRIC_FREQ (10) // Hz
@ -108,7 +111,7 @@ typedef struct _machine_pwm_obj_t {
int mode;
int channel;
int timer;
int duty_x; // PWM_RES_10_BIT if duty(), UI_RES_16_BIT if duty_u16(), -UI_RES_16_BIT if duty_ns()
int duty_x; // PWM_RES_10_BIT if duty(), HIGHEST_PWM_RES if duty_u16(), -HIGHEST_PWM_RES if duty_ns()
int duty_u10; // stored values from previous duty setters
int duty_u16; // - / -
int duty_ns; // - / -
@ -237,7 +240,6 @@ STATIC void set_freq(machine_pwm_obj_t *self, unsigned int freq, ledc_timer_conf
}
// Configure the new resolution and frequency
unsigned int save_duty_resolution = timer->duty_resolution;
timer->duty_resolution = res;
timer->freq_hz = freq;
timer->clk_cfg = LEDC_USE_APB_CLK;
@ -258,17 +260,15 @@ STATIC void set_freq(machine_pwm_obj_t *self, unsigned int freq, ledc_timer_conf
if (self->mode == LEDC_LOW_SPEED_MODE) {
check_esp_err(ledc_timer_rst(self->mode, self->timer));
}
}
// Save the same duty cycle when frequency is changed
if (save_duty_resolution != timer->duty_resolution) {
if (self->duty_x == UI_RES_16_BIT) {
set_duty_u16(self, self->duty_u16);
} else if (self->duty_x == PWM_RES_10_BIT) {
set_duty_u10(self, self->duty_u10);
} else if (self->duty_x == -UI_RES_16_BIT) {
set_duty_ns(self, self->duty_ns);
}
}
// Save the same duty cycle when frequency is changed
if (self->duty_x == HIGHEST_PWM_RES) {
set_duty_u16(self, self->duty_u16);
} else if (self->duty_x == PWM_RES_10_BIT) {
set_duty_u10(self, self->duty_u10);
} else if (self->duty_x == -HIGHEST_PWM_RES) {
set_duty_ns(self, self->duty_ns);
}
}
@ -293,11 +293,18 @@ STATIC int duty_to_ns(machine_pwm_obj_t *self, int duty) {
#define get_duty_raw(self) ledc_get_duty(self->mode, self->channel)
STATIC uint32_t get_duty_u16(machine_pwm_obj_t *self) {
return ledc_get_duty(self->mode, self->channel) << (UI_RES_16_BIT - timers[TIMER_IDX(self->mode, self->timer)].duty_resolution);
int resolution = timers[TIMER_IDX(self->mode, self->timer)].duty_resolution;
int duty = ledc_get_duty(self->mode, self->channel);
if (resolution <= UI_RES_16_BIT) {
duty <<= (UI_RES_16_BIT - resolution);
} else {
duty >>= (resolution - UI_RES_16_BIT);
}
return duty;
}
STATIC uint32_t get_duty_u10(machine_pwm_obj_t *self) {
return get_duty_u16(self) >> (UI_RES_16_BIT - LEDC_TIMER_10_BIT);
return get_duty_u16(self) >> 6; // Scale down from 16 bit to 10 bit resolution
}
STATIC uint32_t get_duty_ns(machine_pwm_obj_t *self) {
@ -309,7 +316,12 @@ STATIC void set_duty_u16(machine_pwm_obj_t *self, int duty) {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("duty_u16 must be from 0 to %d"), UI_MAX_DUTY);
}
ledc_timer_config_t timer = timers[TIMER_IDX(self->mode, self->timer)];
int channel_duty = duty >> (UI_RES_16_BIT - timer.duty_resolution);
int channel_duty;
if (timer.duty_resolution <= UI_RES_16_BIT) {
channel_duty = duty >> (UI_RES_16_BIT - timer.duty_resolution);
} else {
channel_duty = duty << (timer.duty_resolution - UI_RES_16_BIT);
}
int max_duty = (1 << timer.duty_resolution) - 1;
if (channel_duty < 0) {
channel_duty = 0;
@ -333,7 +345,7 @@ STATIC void set_duty_u16(machine_pwm_obj_t *self, int duty) {
}
*/
self->duty_x = UI_RES_16_BIT;
self->duty_x = HIGHEST_PWM_RES;
self->duty_u16 = duty;
}
@ -341,7 +353,7 @@ STATIC void set_duty_u10(machine_pwm_obj_t *self, int duty) {
if ((duty < 0) || (duty > MAX_DUTY_U10)) {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("duty must be from 0 to %u"), MAX_DUTY_U10);
}
set_duty_u16(self, duty << (UI_RES_16_BIT - LEDC_TIMER_10_BIT));
set_duty_u16(self, duty << (UI_RES_16_BIT - PWM_RES_10_BIT));
self->duty_x = PWM_RES_10_BIT;
self->duty_u10 = duty;
}
@ -351,7 +363,7 @@ STATIC void set_duty_ns(machine_pwm_obj_t *self, int ns) {
mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("duty_ns must be from 0 to %d ns"), duty_to_ns(self, UI_MAX_DUTY));
}
set_duty_u16(self, ns_to_duty(self, ns));
self->duty_x = -UI_RES_16_BIT;
self->duty_x = -HIGHEST_PWM_RES;
self->duty_ns = ns;
}
@ -424,7 +436,7 @@ STATIC void mp_machine_pwm_print(const mp_print_t *print, mp_obj_t self_in, mp_p
if (self->duty_x == PWM_RES_10_BIT) {
mp_printf(print, ", duty=%d", get_duty_u10(self));
} else if (self->duty_x == -UI_RES_16_BIT) {
} else if (self->duty_x == -HIGHEST_PWM_RES) {
mp_printf(print, ", duty_ns=%d", get_duty_ns(self));
} else {
mp_printf(print, ", duty_u16=%d", get_duty_u16(self));