feat(ledc): Improve timer management with frequency/resolution matching (espressif#11452)

* feat(ledc): Improve timer management with frequency/resolution matching * fix(ci): Fix uninitialized timer variable warning * Update cores/esp32/esp32-hal-ledc.c Co-authored-by: Lucas Saavedra Vaz <32426024+lucasssvaz@users.noreply.github.com> * ci(pre-commit): Apply automatic fixes --------- Co-authored-by: Lucas Saavedra Vaz <32426024+lucasssvaz@users.noreply.github.com> Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>

Author: 3 people

cores/esp32/esp32-hal-ledc.c

@@ -45,6 +45,93 @@ typedef struct {
 
 ledc_periph_t ledc_handle = {0};
 
+// Helper function to find a timer with matching frequency and resolution
+static bool find_matching_timer(uint8_t speed_mode, uint32_t freq, uint8_t resolution, uint8_t *timer_num) {
+ log_d("Searching for timer with freq=%u, resolution=%u", freq, resolution);
+ // Check all channels to find one with matching frequency and resolution
+ for (uint8_t i = 0; i < SOC_GPIO_PIN_COUNT; i++) {
+ if (!perimanPinIsValid(i)) {
+ continue;
+ }
+ peripheral_bus_type_t type = perimanGetPinBusType(i);
+ if (type == ESP32_BUS_TYPE_LEDC) {
+ ledc_channel_handle_t *bus = (ledc_channel_handle_t *)perimanGetPinBus(i, ESP32_BUS_TYPE_LEDC);
+ if (bus != NULL && (bus->channel / 8) == speed_mode && bus->freq_hz == freq && bus->channel_resolution == resolution) {
+ log_d("Found matching timer %u for freq=%u, resolution=%u", bus->timer_num, freq, resolution);
+ *timer_num = bus->timer_num;
+ return true;
+ }
+ }
+ }
+ log_d("No matching timer found for freq=%u, resolution=%u", freq, resolution);
+ return false;
+}
+
+// Helper function to find an unused timer
+static bool find_free_timer(uint8_t speed_mode, uint8_t *timer_num) {
+ // Check which timers are in use
+ uint8_t used_timers = 0;
+ for (uint8_t i = 0; i < SOC_GPIO_PIN_COUNT; i++) {
+ if (!perimanPinIsValid(i)) {
+ continue;
+ }
+ peripheral_bus_type_t type = perimanGetPinBusType(i);
+ if (type == ESP32_BUS_TYPE_LEDC) {
+ ledc_channel_handle_t *bus = (ledc_channel_handle_t *)perimanGetPinBus(i, ESP32_BUS_TYPE_LEDC);
+ if (bus != NULL && (bus->channel / 8) == speed_mode) {
+ log_d("Timer %u is in use by channel %u", bus->timer_num, bus->channel);
+ used_timers |= (1 << bus->timer_num);
+ }
+ }
+ }
+
+ // Find first unused timer
+ for (uint8_t i = 0; i < SOC_LEDC_TIMER_NUM; i++) {
+ if (!(used_timers & (1 << i))) {
+ log_d("Found free timer %u", i);
+ *timer_num = i;
+ return true;
+ }
+ }
+ log_e("No free timers available");
+ return false;
+}
+
+// Helper function to remove a channel from a timer and clear timer if no channels are using it
+static void remove_channel_from_timer(uint8_t speed_mode, uint8_t timer_num, uint8_t channel) {
+ log_d("Removing channel %u from timer %u in speed_mode %u", channel, timer_num, speed_mode);
+
+ // Check if any other channels are using this timer
+ bool timer_in_use = false;
+ for (uint8_t i = 0; i < SOC_GPIO_PIN_COUNT; i++) {
+ if (!perimanPinIsValid(i)) {
+ continue;
+ }
+ peripheral_bus_type_t type = perimanGetPinBusType(i);
+ if (type == ESP32_BUS_TYPE_LEDC) {
+ ledc_channel_handle_t *bus = (ledc_channel_handle_t *)perimanGetPinBus(i, ESP32_BUS_TYPE_LEDC);
+ if (bus != NULL && (bus->channel / 8) == speed_mode && bus->timer_num == timer_num && bus->channel != channel) {
+ log_d("Timer %u is still in use by channel %u", timer_num, bus->channel);
+ timer_in_use = true;
+ break;
+ }
+ }
+ }
+
+ if (!timer_in_use) {
+ log_d("No other channels using timer %u, deconfiguring timer", timer_num);
+ // Stop the timer
+ ledc_timer_pause(speed_mode, timer_num);
+ // Deconfigure the timer
+ ledc_timer_config_t ledc_timer;
+ memset((void *)&ledc_timer, 0, sizeof(ledc_timer_config_t));
+ ledc_timer.speed_mode = speed_mode;
+ ledc_timer.timer_num = timer_num;
+ ledc_timer.deconfigure = true;
+ ledc_timer_config(&ledc_timer);
+ }
+}
+
 static bool fade_initialized = false;
 
 static ledc_clk_cfg_t clock_source = LEDC_DEFAULT_CLK;
@@ -81,6 +168,8 @@ static bool ledcDetachBus(void *bus) {
  }
  pinMatrixOutDetach(handle->pin, false, false);
  if (!channel_found) {
+ uint8_t group = (handle->channel / 8);
+ remove_channel_from_timer(group, handle->timer_num, handle->channel % 8);
  ledc_handle.used_channels &= ~(1UL << handle->channel);
  }
  free(handle);
@@ -117,26 +206,37 @@ bool ledcAttachChannel(uint8_t pin, uint32_t freq, uint8_t resolution, uint8_t c
  return false;
  }
 
- uint8_t group = (channel / 8), timer = ((channel / 2) % 4);
+ uint8_t group = (channel / 8);
+ uint8_t timer = 0;
  bool channel_used = ledc_handle.used_channels & (1UL << channel);
+
  if (channel_used) {
  log_i("Channel %u is already set up, given frequency and resolution will be ignored", channel);
  if (ledc_set_pin(pin, group, channel % 8) != ESP_OK) {
  log_e("Attaching pin to already used channel failed!");
  return false;
  }
  } else {
- ledc_timer_config_t ledc_timer;
- memset((void *)&ledc_timer, 0, sizeof(ledc_timer_config_t));
- ledc_timer.speed_mode = group;
- ledc_timer.timer_num = timer;
- ledc_timer.duty_resolution = resolution;
- ledc_timer.freq_hz = freq;
- ledc_timer.clk_cfg = clock_source;
+ // Find a timer with matching frequency and resolution, or a free timer
+ if (!find_matching_timer(group, freq, resolution, &timer)) {
+ if (!find_free_timer(group, &timer)) {
+ log_e("No free timers available for speed mode %u", group);
+ return false;
+ }
 
- if (ledc_timer_config(&ledc_timer) != ESP_OK) {
- log_e("ledc setup failed!");
- return false;
+ // Configure the timer if we're using a new one
+ ledc_timer_config_t ledc_timer;
+ memset((void *)&ledc_timer, 0, sizeof(ledc_timer_config_t));
+ ledc_timer.speed_mode = group;
+ ledc_timer.timer_num = timer;
+ ledc_timer.duty_resolution = resolution;
+ ledc_timer.freq_hz = freq;
+ ledc_timer.clk_cfg = clock_source;
+
+ if (ledc_timer_config(&ledc_timer) != ESP_OK) {
+ log_e("ledc setup failed!");
+ return false;
+ }
  }
 
  uint32_t duty = ledc_get_duty(group, (channel % 8));
@@ -157,6 +257,8 @@ bool ledcAttachChannel(uint8_t pin, uint32_t freq, uint8_t resolution, uint8_t c
  ledc_channel_handle_t *handle = (ledc_channel_handle_t *)malloc(sizeof(ledc_channel_handle_t));
  handle->pin = pin;
  handle->channel = channel;
+ handle->timer_num = timer;
+ handle->freq_hz = freq;
 #ifndef SOC_LEDC_SUPPORT_FADE_STOP
  handle->lock = NULL;
 #endif

cores/esp32/esp32-hal-ledc.h

@@ -51,6 +51,8 @@ typedef struct {
  uint8_t pin; // Pin assigned to channel
  uint8_t channel; // Channel number
  uint8_t channel_resolution; // Resolution of channel
+ uint8_t timer_num; // Timer number used by this channel
+ uint32_t freq_hz; // Frequency configured for this channel
  voidFuncPtr fn;
  void *arg;
 #ifndef SOC_LEDC_SUPPORT_FADE_STOP