Pin manager support for sharing multipin buses.

wled00/pin_manager.cpp

@@ -1,6 +1,7 @@
 #include "pin_manager.h"
 #include "wled.h"
 
+#ifdef WLED_DEBUG
 static void DebugPrintOwnerTag(PinOwner tag)
 {
   uint32_t q = static_cast<uint8_t>(tag);
@@ -10,6 +11,7 @@ static void DebugPrintOwnerTag(PinOwner tag)
     DEBUG_PRINT(F("(no owner)"));
   }
 }
+#endif
 
 /// Actual allocation/deallocation routines
 bool PinManagerClass::deallocatePin(byte gpio, PinOwner tag)
@@ -19,12 +21,14 @@ bool PinManagerClass::deallocatePin(byte gpio, PinOwner tag)
 
   // if a non-zero ownerTag, only allow de-allocation if the owner's tag is provided
   if ((ownerTag[gpio] != PinOwner::None) && (ownerTag[gpio] != tag)) {
+    #ifdef WLED_DEBUG
     DEBUG_PRINT(F("PIN DEALLOC: IO "));
     DEBUG_PRINT(gpio);
     DEBUG_PRINT(F(" allocated by "));
     DebugPrintOwnerTag(ownerTag[gpio]);
     DEBUG_PRINT(F(", but attempted de-allocation by "));
     DebugPrintOwnerTag(tag);
+    #endif
     return false;
   }
   
@@ -34,6 +38,49 @@ bool PinManagerClass::deallocatePin(byte gpio, PinOwner tag)
   ownerTag[gpio] = PinOwner::None;
   return true;
 }
+
+// support function for deallocating multiple pins
+bool PinManagerClass::deallocateMultiplePins(const uint8_t *pinArray, byte arrayElementCount, PinOwner tag)
+{
+  bool shouldFail = false;
+  DEBUG_PRINTLN(F("MULTIPIN DEALLOC"));
+  // first verify the pins are OK and allocated by selected owner
+  for (int i = 0; i < arrayElementCount; i++) {
+    byte gpio = pinArray[i];
+    if (gpio == 0xFF) {
+      // explicit support for io -1 as a no-op (no allocation of pin),
+      // as this can greatly simplify configuration arrays
+      continue;
+    }
+    if (isPinAllocated(gpio, tag)) {
+      // if the current pin is allocated by selected owner it is possible to release it
+      continue;
+    }
+    #ifdef WLED_DEBUG
+    DEBUG_PRINT(F("PIN DEALLOC: IO "));
+    DEBUG_PRINT(gpio);
+    DEBUG_PRINT(F(" allocated by "));
+    DebugPrintOwnerTag(ownerTag[gpio]);
+    DEBUG_PRINT(F(", but attempted de-allocation by "));
+    DebugPrintOwnerTag(tag);
+    #endif
+    shouldFail = true;
+  }
+  if (shouldFail) {
+    return false; // no pins deallocated
+  }
+  if (tag==PinOwner::HW_I2C) {
+    if (i2cAllocCount && --i2cAllocCount>0) {
+      // no deallocation done until last owner releases pins
+      return true;
+    }
+  }
+  for (int i = 0; i < arrayElementCount; i++) {
+    deallocatePin(pinArray[i], tag);
+  }
+  return true;
+}
+
 bool PinManagerClass::allocateMultiplePins(const managed_pin_type * mptArray, byte arrayElementCount, PinOwner tag)
 {
   bool shouldFail = false;
@@ -46,17 +93,24 @@ bool PinManagerClass::allocateMultiplePins(const managed_pin_type * mptArray, by
       continue;
     }
     if (!isPinOk(gpio, mptArray[i].isOutput)) {
+      #ifdef WLED_DEBUG
       DEBUG_PRINT(F("PIN ALLOC: Invalid pin attempted to be allocated: "));
       DEBUG_PRINT(gpio);
       DEBUG_PRINTLN(F(""));
+      #endif
       shouldFail = true;
     }
-    if (isPinAllocated(gpio)) {
+    if (tag==PinOwner::HW_I2C && isPinAllocated(gpio, tag)) {
+      // allow multiple "allocations" of HW I2C bus pins
+      continue;
+    } else if (isPinAllocated(gpio)) {
+      #ifdef WLED_DEBUG
       DEBUG_PRINT(F("PIN ALLOC: FAIL: IO ")); 
       DEBUG_PRINT(gpio);
       DEBUG_PRINT(F(" already allocated by "));
       DebugPrintOwnerTag(ownerTag[gpio]);
       DEBUG_PRINTLN(F(""));
+      #endif
       shouldFail = true;
     }
   }
@@ -64,6 +118,8 @@ bool PinManagerClass::allocateMultiplePins(const managed_pin_type * mptArray, by
     return false;
   }
 
+  if (tag==PinOwner::HW_I2C) i2cAllocCount++;
+
   // all pins are available .. track each one
   for (int i = 0; i < arrayElementCount; i++) {
     byte gpio = mptArray[i].pin;
@@ -79,15 +135,19 @@ bool PinManagerClass::allocateMultiplePins(const managed_pin_type * mptArray, by
   }
   return true;
 }
+
 bool PinManagerClass::allocatePin(byte gpio, bool output, PinOwner tag)
 {
-  if (!isPinOk(gpio, output)) return false;
+  // HW I2C pins have to be allocated using allocateMultiplePins variant since there is always SCL/SDA pair
+  if (!isPinOk(gpio, output) || tag==PinOwner::HW_I2C) return false;
   if (isPinAllocated(gpio)) {
+    #ifdef WLED_DEBUG
     DEBUG_PRINT(F("PIN ALLOC: Pin ")); 
     DEBUG_PRINT(gpio);
     DEBUG_PRINT(F(" already allocated by "));
     DebugPrintOwnerTag(ownerTag[gpio]);
     DEBUG_PRINTLN(F(""));
+    #endif
     return false;
   }
 
@@ -106,7 +166,7 @@ bool PinManagerClass::isPinAllocated(byte gpio, PinOwner tag)
   if (!isPinOk(gpio, false)) return true;
   if ((tag != PinOwner::None) && (ownerTag[gpio] != tag)) return false;
   byte by = gpio >> 3;
-  byte bi = gpio - 8*by;
+  byte bi = gpio - (by<<3);
   return bitRead(pinAlloc[by], bi);
 }
 

wled00/pin_manager.h

@@ -8,7 +8,7 @@
 
 typedef struct PinManagerPinType {
   int8_t pin;
-  uint8_t isOutput;
+  bool   isOutput;
 } managed_pin_type;
 
 /*
@@ -23,7 +23,6 @@ typedef struct PinManagerPinType {
 enum struct PinOwner : uint8_t {
   None          = 0,      // default == legacy == unspecified owner
   // High bit is set for all built-in pin owners
-  // StatusLED  -- THIS SHOULD NEVER BE ALLOCATED -- see handleStatusLED()
   Ethernet      = 0x81,
   BusDigital    = 0x82,
   BusDigital2   = 0x83,
@@ -34,26 +33,27 @@ enum struct PinOwner : uint8_t {
   SPI_RAM       = 0x88,   // 'SpiR' == SPI RAM
   DebugOut      = 0x89,   // 'Dbg'  == debug output always IO1
   DMX           = 0x8A,   // 'DMX'  == hard-coded to IO2
+  HW_I2C        = 0x8B,   // 'I2C'  == hardware I2C pins (4&5 on ESP8266, 21&22 on ESP32)
   // Use UserMod IDs from const.h here
   UM_Unspecified       = USERMOD_ID_UNSPECIFIED,        // 0x01
   UM_Example           = USERMOD_ID_EXAMPLE,            // 0x02 // Usermod "usermod_v2_example.h"
   UM_Temperature       = USERMOD_ID_TEMPERATURE,        // 0x03 // Usermod "usermod_temperature.h"
   // #define USERMOD_ID_FIXNETSERVICES                  // 0x04 // Usermod "usermod_Fix_unreachable_netservices.h" -- Does not allocate pins
   UM_PIR               = USERMOD_ID_PIRSWITCH,          // 0x05 // Usermod "usermod_PIR_sensor_switch.h"
-  // #define USERMOD_ID_IMU                             // 0x06 // Usermod "usermod_mpu6050_imu.h" -- Uses "standard" I2C pins ... TODO -- enable shared I2C bus use
+  // #define USERMOD_ID_IMU                             // 0x06 // Usermod "usermod_mpu6050_imu.h" -- Uses "standard" HW_I2C pins
-  UM_FourLineDisplay   = USERMOD_ID_FOUR_LINE_DISP,     // 0x07 // Usermod "usermod_v2_four_line_display.h
+  UM_FourLineDisplay   = USERMOD_ID_FOUR_LINE_DISP,     // 0x07 // Usermod "usermod_v2_four_line_display.h -- May use "standard" HW_I2C pins
   UM_RotaryEncoderUI   = USERMOD_ID_ROTARY_ENC_UI,      // 0x08 // Usermod "usermod_v2_rotary_encoder_ui.h"
   // #define USERMOD_ID_AUTO_SAVE                       // 0x09 // Usermod "usermod_v2_auto_save.h" -- Does not allocate pins
   // #define USERMOD_ID_DHT                             // 0x0A // Usermod "usermod_dht.h" -- Statically allocates pins, not compatible with pinManager?
   // #define USERMOD_ID_MODE_SORT                       // 0x0B // Usermod "usermod_v2_mode_sort.h" -- Does not allocate pins
-  // #define USERMOD_ID_VL53L0X                         // 0x0C // Usermod "usermod_vl53l0x_gestures.h" -- Uses "standard" I2C pins ... TODO -- enable shared I2C bus use
+  // #define USERMOD_ID_VL53L0X                         // 0x0C // Usermod "usermod_vl53l0x_gestures.h" -- Uses "standard" HW_I2C pins
   UM_MultiRelay        = USERMOD_ID_MULTI_RELAY,        // 0x0D // Usermod "usermod_multi_relay.h"
   UM_AnimatedStaircase = USERMOD_ID_ANIMATED_STAIRCASE, // 0x0E // Usermod "Animated_Staircase.h"
-  // #define USERMOD_ID_RTC                             // 0x0F // Usermod "usermod_rtc.h" -- Uses "standard" I2C pins ... TODO -- enable shared I2C bus use
+  // #define USERMOD_ID_RTC                             // 0x0F // Usermod "usermod_rtc.h" -- Uses "standard" HW_I2C pins 
   // #define USERMOD_ID_ELEKSTUBE_IPS                   // 0x10 // Usermod "usermod_elekstube_ips.h" -- Uses quite a few pins ... see Hardware.h and User_Setup.h
   // #define USERMOD_ID_SN_PHOTORESISTOR                // 0x11 // Usermod "usermod_sn_photoresistor.h" -- Uses hard-coded pin (PHOTORESISTOR_PIN == A0), but could be easily updated to use pinManager
   UM_RGBRotaryEncoder  = USERMOD_RGB_ROTARY_ENCODER,    // 0x16 // Usermod "rgb-rotary-encoder.h"
-  UM_QuinLEDAnPenta    = USERMOD_ID_QUINLED_AN_PENTA,   // 0x17 // Usermod "quinled-an-penta.h"
+  UM_QuinLEDAnPenta    = USERMOD_ID_QUINLED_AN_PENTA    // 0x17 // Usermod "quinled-an-penta.h"
 };
 static_assert(0u == static_cast<uint8_t>(PinOwner::None), "PinOwner::None must be zero, so default array initialization works as expected");
 
@@ -67,10 +67,13 @@ class PinManagerClass {
   uint8_t ledcAlloc[2] = {0x00, 0x00}; //16 LEDC channels
   PinOwner ownerTag[40] = { PinOwner::None };
   #endif
+  uint8_t i2cAllocCount = 0; // allow multiple allocation of I2C bus pins but keep track of allocations
 
   public:
   // De-allocates a single pin
   bool deallocatePin(byte gpio, PinOwner tag);
+  // De-allocates multiple pins but only if all can be deallocated (PinOwner has to be specified)
+  bool deallocateMultiplePins(const uint8_t *pinArray, byte arrayElementCount, PinOwner tag);
   // Allocates a single pin, with an owner tag.
   // De-allocation requires the same owner tag (or override)
   bool allocatePin(byte gpio, bool output, PinOwner tag);
@@ -85,11 +88,13 @@ class PinManagerClass {
   #endif
   inline bool allocatePin(byte gpio, bool output = true) { return allocatePin(gpio, output, PinOwner::None); }
   #if !defined(ESP8266) // ESP8266 compiler doesn't understand deprecated attribute
-  [[deprecated("Replaced by three-parameter deallocatePin(gpio, output, ownerTag), for improved debugging")]]
+  [[deprecated("Replaced by two-parameter deallocatePin(gpio, ownerTag), for improved debugging")]]
   #endif
   inline void deallocatePin(byte gpio) { deallocatePin(gpio, PinOwner::None); }
 
+  // will return true for reserved pins
   bool isPinAllocated(byte gpio, PinOwner tag = PinOwner::None);
+  // will return false for reserved pins
   bool isPinOk(byte gpio, bool output = true);
 
   PinOwner getPinOwner(byte gpio);