From 1ffee9c4d2d89823346b48585a987e9ab7233a93 Mon Sep 17 00:00:00 2001 From: Ali Jafri Date: Tue, 20 Aug 2024 03:12:41 +0530 Subject: [PATCH] Fix RP2040 Neopixel flickering issue (#7307) --- .../rp2040_pio_led_strip/led_strip.cpp | 36 ++++++++++++++++--- .../rp2040_pio_led_strip/led_strip.h | 5 +++ 2 files changed, 36 insertions(+), 5 deletions(-) diff --git a/esphome/components/rp2040_pio_led_strip/led_strip.cpp b/esphome/components/rp2040_pio_led_strip/led_strip.cpp index 3e5e82898d..2aaa2ceb19 100644 --- a/esphome/components/rp2040_pio_led_strip/led_strip.cpp +++ b/esphome/components/rp2040_pio_led_strip/led_strip.cpp @@ -7,8 +7,10 @@ #include #include +#include #include #include +#include namespace esphome { namespace rp2040_pio_led_strip { @@ -23,6 +25,19 @@ static std::map conf_count_ = { {CHIPSET_WS2812, false}, {CHIPSET_WS2812B, false}, {CHIPSET_SK6812, false}, {CHIPSET_SM16703, false}, {CHIPSET_CUSTOM, false}, }; +static bool dma_chan_active_[12]; +static struct semaphore dma_write_complete_sem_[12]; + +// DMA interrupt service routine +void RP2040PIOLEDStripLightOutput::dma_write_complete_handler_() { + uint32_t channel = dma_hw->ints0; + for (uint dma_chan = 0; dma_chan < 12; ++dma_chan) { + if (RP2040PIOLEDStripLightOutput::dma_chan_active_[dma_chan] && (channel & (1u << dma_chan))) { + dma_hw->ints0 = (1u << dma_chan); // Clear the interrupt + sem_release(&RP2040PIOLEDStripLightOutput::dma_write_complete_sem_[dma_chan]); // Handle the interrupt + } + } +} void RP2040PIOLEDStripLightOutput::setup() { ESP_LOGCONFIG(TAG, "Setting up RP2040 LED Strip..."); @@ -57,22 +72,22 @@ void RP2040PIOLEDStripLightOutput::setup() { // but there are only 4 state machines on each PIO so we can only have 4 strips per PIO uint offset = 0; - if (num_instance_[this->pio_ == pio0 ? 0 : 1] > 4) { + if (RP2040PIOLEDStripLightOutput::num_instance_[this->pio_ == pio0 ? 0 : 1] > 4) { ESP_LOGE(TAG, "Too many instances of PIO program"); this->mark_failed(); return; } // keep track of how many instances of the PIO program are running on each PIO - num_instance_[this->pio_ == pio0 ? 0 : 1]++; + RP2040PIOLEDStripLightOutput::num_instance_[this->pio_ == pio0 ? 0 : 1]++; // if there are multiple strips of the same chipset, we can reuse the same PIO program and save space if (this->conf_count_[this->chipset_]) { - offset = chipset_offsets_[this->chipset_]; + offset = RP2040PIOLEDStripLightOutput::chipset_offsets_[this->chipset_]; } else { // Load the assembled program into the PIO and get its location in the PIO's instruction memory and save it offset = pio_add_program(this->pio_, this->program_); - chipset_offsets_[this->chipset_] = offset; - conf_count_[this->chipset_] = true; + RP2040PIOLEDStripLightOutput::chipset_offsets_[this->chipset_] = offset; + RP2040PIOLEDStripLightOutput::conf_count_[this->chipset_] = true; } // Configure the state machine's PIO, and start it @@ -93,6 +108,9 @@ void RP2040PIOLEDStripLightOutput::setup() { return; } + // Mark the DMA channel as active + RP2040PIOLEDStripLightOutput::dma_chan_active_[this->dma_chan_] = true; + this->dma_config_ = dma_channel_get_default_config(this->dma_chan_); channel_config_set_transfer_data_size( &this->dma_config_, @@ -109,6 +127,13 @@ void RP2040PIOLEDStripLightOutput::setup() { false // don't start yet ); + // Initialize the semaphore for this DMA channel + sem_init(&RP2040PIOLEDStripLightOutput::dma_write_complete_sem_[this->dma_chan_], 1, 1); + + irq_set_exclusive_handler(DMA_IRQ_0, dma_write_complete_handler_); // after DMA all data, raise an interrupt + dma_channel_set_irq0_enabled(this->dma_chan_, true); // map DMA channel to interrupt + irq_set_enabled(DMA_IRQ_0, true); // enable interrupt + this->init_(this->pio_, this->sm_, offset, this->pin_, this->max_refresh_rate_); } @@ -126,6 +151,7 @@ void RP2040PIOLEDStripLightOutput::write_state(light::LightState *state) { } // the bits are already in the correct order for the pio program so we can just copy the buffer using DMA + sem_acquire_blocking(&RP2040PIOLEDStripLightOutput::dma_write_complete_sem_[this->dma_chan_]); dma_channel_transfer_from_buffer_now(this->dma_chan_, this->buf_, this->get_buffer_size_()); } diff --git a/esphome/components/rp2040_pio_led_strip/led_strip.h b/esphome/components/rp2040_pio_led_strip/led_strip.h index 9976842f02..7b62648974 100644 --- a/esphome/components/rp2040_pio_led_strip/led_strip.h +++ b/esphome/components/rp2040_pio_led_strip/led_strip.h @@ -13,6 +13,7 @@ #include #include #include +#include #include namespace esphome { @@ -95,6 +96,8 @@ class RP2040PIOLEDStripLightOutput : public light::AddressableLight { size_t get_buffer_size_() const { return this->num_leds_ * (3 + this->is_rgbw_); } + static void dma_write_complete_handler_(); + uint8_t *buf_{nullptr}; uint8_t *effect_data_{nullptr}; @@ -120,6 +123,8 @@ class RP2040PIOLEDStripLightOutput : public light::AddressableLight { inline static int num_instance_[2]; inline static std::map conf_count_; inline static std::map chipset_offsets_; + inline static bool dma_chan_active_[12]; + inline static struct semaphore dma_write_complete_sem_[12]; }; } // namespace rp2040_pio_led_strip