Merge pull request #436 from adafruit/rp2350_fixes

clean up and hand-add some of #381

Author: ladyada

Adafruit_NeoPixel.cpp

@@ -86,16 +86,7 @@ Adafruit_NeoPixel::Adafruit_NeoPixel(uint16_t n, int16_t p, neoPixelType t)
   updateType(t);
   updateLength(n);
   setPin(p);
-#if defined(ARDUINO_ARCH_RP2040)
-  // Find a free SM on one of the PIO's
-  sm = pio_claim_unused_sm(pio, false); // don't panic
-  // Try pio1 if SM not found
-  if (sm < 0) {
-    pio = pio1;
-    sm = pio_claim_unused_sm(pio, true); // panic if no SM is free
-  }
-  init = true;
-#endif
+
 #if defined(ESP32)
 #if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 0, 0)
   espInit();
@@ -133,20 +124,43 @@ Adafruit_NeoPixel::~Adafruit_NeoPixel() {
   numLEDs = numBytes = 0;
   show();
 #endif
+
+
+#if defined(ARDUINO_ARCH_RP2040)
+  // Release any PIO
+  rp2040releasePIO();
+#endif
+
   free(pixels);
   if (pin >= 0)
     pinMode(pin, INPUT);
 }
 
 /*!
   @brief   Configure NeoPixel pin for output.
+  @returns False if we weren't able to claim resources required
 */
-void Adafruit_NeoPixel::begin(void) {
+bool Adafruit_NeoPixel::begin(void) {
   if (pin >= 0) {
     pinMode(pin, OUTPUT);
     digitalWrite(pin, LOW);
+  } else {
+    begun = false;
+    return false;
   }
+
+#if defined(ARDUINO_ARCH_RP2040)
+  // if we're calling begin() again, unclaim any existing PIO resc.
+  rp2040releasePIO();
+  if (! rp2040claimPIO()) {
+    begun = false;
+    return false;
+  }
+  
+#endif
+
   begun = true;
+  return true;
 }
 
 /*!
@@ -209,38 +223,8 @@ void Adafruit_NeoPixel::updateType(neoPixelType t) {
   }
 }
 
-// RP2040 specific driver
-#if defined(ARDUINO_ARCH_RP2040)
-void Adafruit_NeoPixel::rp2040Init(uint8_t pin, bool is800KHz)
-{
-  uint offset = pio_add_program(pio, &ws2812_program);
 
-  if (is800KHz)
-  {
-    // 800kHz, 8 bit transfers
-    ws2812_program_init(pio, sm, offset, pin, 800000, 8);
-  }
-  else
-  {
-    // 400kHz, 8 bit transfers
-    ws2812_program_init(pio, sm, offset, pin, 400000, 8);
-  }
-}
-// Not a user API
-void  Adafruit_NeoPixel::rp2040Show(uint8_t pin, uint8_t *pixels, uint32_t numBytes, bool is800KHz)
-{
-  if (this->init)
-  {
-    // On first pass through initialise the PIO
-    rp2040Init(pin, is800KHz);
-    this->init = false;
-  }
-
-  while(numBytes--)
-    // Bits for transmission must be shifted to top 8 bits
-    pio_sm_put_blocking(pio, sm, ((uint32_t)*pixels++)<< 24);
-}
-#elif defined(ARDUINO_ARCH_CH32)
+#if defined(ARDUINO_ARCH_CH32)
 
 // F_CPU is defined to SystemCoreClock (not constant number)
 #if SYSCLK_FREQ_144MHz_HSE == 144000000 || SYSCLK_FREQ_HSE == 144000000 || \
@@ -1908,7 +1892,7 @@ void Adafruit_NeoPixel::show(void) {
 
 #elif defined(ARDUINO_ARCH_RP2040)
   // Use PIO
-  rp2040Show(pin, pixels, numBytes, is800KHz);
+  rp2040Show(pixels, numBytes);
 
 #elif defined(TEENSYDUINO) &&                                                  \
     defined(KINETISK) // Teensy 3.0, 3.1, 3.2, 3.5, 3.6
@@ -3382,8 +3366,7 @@ if(is800KHz) {
 #elif defined(ARDUINO_ARCH_CH32)
   ch32Show(gpioPort, gpioPin, pixels, numBytes, is800KHz);
 #elif defined(ARDUINO_ARCH_RP2040) && defined(__riscv)
-  // Use PIO
-  rp2040Show(pin, pixels, numBytes, is800KHz);
+  rp2040Show(pixels, numBytes);  // Use PIO
 #else
 #error Architecture not supported
 #endif

Adafruit_NeoPixel.h

@@ -37,12 +37,7 @@
 #define ADAFRUIT_NEOPIXEL_H
 
 #ifdef ARDUINO
-#if (ARDUINO >= 100)
 #include <Arduino.h>
-#else
-#include <WProgram.h>
-#include <pins_arduino.h>
-#endif
 
 #ifdef USE_TINYUSB // For Serial when selecting TinyUSB
 #include <Adafruit_TinyUSB.h>
@@ -235,7 +230,7 @@ class Adafruit_NeoPixel {
   Adafruit_NeoPixel(void);
   ~Adafruit_NeoPixel();
 
-  void begin(void);
+  bool begin(void);
   void show(void);
   void setPin(int16_t p);
   void setPixelColor(uint16_t n, uint8_t r, uint8_t g, uint8_t b);
@@ -389,15 +384,20 @@ class Adafruit_NeoPixel {
 
 private:
 #if defined(ARDUINO_ARCH_RP2040)
-  void  rp2040Init(uint8_t pin, bool is800KHz);
-  void  rp2040Show(uint8_t pin, uint8_t *pixels, uint32_t numBytes, bool is800KHz);
+  bool   rp2040claimPIO(void);
+  void   rp2040releasePIO(void);
+  void   rp2040Show(uint8_t *pixels, uint32_t numBytes);
+  PIO    pio = NULL;
+  uint   pio_sm = -1;
+  uint   pio_program_offset = 0;
 #endif
 
 protected:
 #ifdef NEO_KHZ400 // If 400 KHz NeoPixel support enabled...
   bool is800KHz; ///< true if 800 KHz pixels
 #endif
-  bool begun;         ///< true if begin() previously called
+
+  bool begun;         ///< true if begin() previously called successfully
   uint16_t numLEDs;   ///< Number of RGB LEDs in strip
   uint16_t numBytes;  ///< Size of 'pixels' buffer below
   int16_t pin;        ///< Output pin number (-1 if not yet set)
@@ -408,22 +408,24 @@ class Adafruit_NeoPixel {
   uint8_t bOffset;    ///< Index of blue byte
   uint8_t wOffset;    ///< Index of white (==rOffset if no white)
   uint32_t endTime;   ///< Latch timing reference
+
 #ifdef __AVR__
   volatile uint8_t *port; ///< Output PORT register
   uint8_t pinMask;        ///< Output PORT bitmask
 #endif
-#if defined(ARDUINO_ARCH_STM32) || defined(ARDUINO_ARCH_ARDUINO_CORE_STM32) || defined(ARDUINO_ARCH_CH32) || defined(_PY32_DEF_)
+
+#if defined(ARDUINO_ARCH_STM32) || \
+    defined(ARDUINO_ARCH_ARDUINO_CORE_STM32) || \
+    defined(ARDUINO_ARCH_CH32) || \
+    defined(_PY32_DEF_)
   GPIO_TypeDef *gpioPort; ///< Output GPIO PORT
   uint32_t gpioPin;       ///< Output GPIO PIN
 #endif
+
 #if defined(TARGET_GIGA) || defined(TARGET_M4)
   mbed::DigitalInOut *gpio;
 #endif
-#if defined(ARDUINO_ARCH_RP2040)
-  PIO pio = pio0;
-  int sm = 0;
-  bool init = true;
-#endif
+
 };
 
 #endif // ADAFRUIT_NEOPIXEL_H

Adafruit_Neopixel_RP2.cpp

@@ -0,0 +1,51 @@
+#if defined(ARDUINO_ARCH_RP2040)// RP2040 specific driver
+
+#include "Adafruit_NeoPixel.h"
+
+bool Adafruit_NeoPixel::rp2040claimPIO(void) {
+  // Find a PIO with enough available space in its instruction memory
+  pio = NULL;
+
+  if (! pio_claim_free_sm_and_add_program_for_gpio_range(&ws2812_program, 
+                                                         &pio, &pio_sm, &pio_program_offset, 
+                                                         pin, 1, true)) {
+    pio = NULL;
+    pio_sm = -1;
+    pio_program_offset = 0;
+    return false; // No PIO available
+  }
+
+  // yay ok!
+  
+  if (is800KHz) {
+    // 800kHz, 8 bit transfers
+    ws2812_program_init(pio, pio_sm, pio_program_offset, pin, 800000, 8);
+  } else {
+    // 400kHz, 8 bit transfers
+    ws2812_program_init(pio, pio_sm, pio_program_offset, pin, 400000, 8);
+  }
+
+  return true;
+}
+
+void Adafruit_NeoPixel::rp2040releasePIO(void) {
+  if (pio == NULL) 
+    return;
+
+  pio_remove_program_and_unclaim_sm(&ws2812_program, pio, pio_sm,  pio_program_offset);
+}
+
+
+// Private, called from show()
+void  Adafruit_NeoPixel::rp2040Show(uint8_t *pixels, uint32_t numBytes)
+{
+  // verify we have a valid PIO and state machine
+  if (! pio || (pio_sm < 0)) {
+    return;
+  }
+
+  while(numBytes--)
+    // Bits for transmission must be shifted to top 8 bits
+    pio_sm_put_blocking(pio, pio_sm, ((uint32_t)*pixels++)<< 24);
+}
+#endif