[hal,wpilib] Add support for second I2C port (#7878)

hal/src/main/native/include/hal/I2CTypes.h

@@ -16,7 +16,7 @@
 
 HAL_ENUM(HAL_I2CPort) {
   HAL_I2C_kInvalid = -1,
-  HAL_I2C_kOnboard,
-  HAL_I2C_kMXP
+  HAL_I2C_kPort0,
+  HAL_I2C_kPort1
 };
 /** @} */

hal/src/main/native/systemcore/I2C.cpp

@@ -18,37 +18,46 @@
 
 #include "HALInitializer.h"
 #include "HALInternal.h"
+#include "PortsInternal.h"
 #include "hal/DIO.h"
 #include "hal/HAL.h"
 
 using namespace hal;
 
-static wpi::mutex digitalI2COnBoardMutex;
-static uint8_t i2COnboardObjCount{0};
-static int i2COnBoardHandle{-1};
+namespace {
+constexpr const char* physicalPorts[kNumI2cBuses] = {"/dev/i2c-1",
+                                                     "/dev/i2c-10"};
+
+struct I2C {
+  wpi::mutex initMutex;
+  int objCount = 0;
+  int fd = -1;
+};
+
+static I2C i2cObjs[kNumI2cBuses];
+}  // namespace
 
 namespace hal::init {
 void InitializeI2C() {}
 }  // namespace hal::init
 
 extern "C" {
-
 void HAL_InitializeI2C(HAL_I2CPort port, int32_t* status) {
   hal::init::CheckInit();
 
-  if (port != 0) {
+  if (port < 0 || port > 2) {
     *status = RESOURCE_OUT_OF_RANGE;
-    hal::SetLastErrorIndexOutOfRange(status, "Invalid Index for I2C", 0, 0,
+    hal::SetLastErrorIndexOutOfRange(status, "Invalid Index for I2C", 0, 1,
                                      port);
     return;
   }
 
-  std::scoped_lock lock(digitalI2COnBoardMutex);
-  i2COnboardObjCount++;
-  if (i2COnboardObjCount > 1) {
+  std::scoped_lock lock(i2cObjs[port].initMutex);
+  i2cObjs[port].objCount++;
+  if (i2cObjs[port].objCount > 1) {
     return;
   }
-  int handle = open("/dev/i2c-1", O_RDWR);
+  int handle = open(physicalPorts[port], O_RDWR);
   if (handle < 0) {
     int err = errno;
     *status = NO_AVAILABLE_RESOURCES;
@@ -56,18 +65,18 @@ void HAL_InitializeI2C(HAL_I2CPort port, int32_t* status) {
                                           std::strerror(err)));
     wpi::print("Failed to open onboard i2c bus: {}\n", std::strerror(err));
     handle = -1;
-    i2COnboardObjCount--;
+    i2cObjs[port].objCount--;
     return;
   }
-  i2COnBoardHandle = handle;
+  i2cObjs[port].fd = handle;
 }
 
 int32_t HAL_TransactionI2C(HAL_I2CPort port, int32_t deviceAddress,
                            const uint8_t* dataToSend, int32_t sendSize,
                            uint8_t* dataReceived, int32_t receiveSize) {
-  if (port != 0) {
+  if (port < 0 || port > 2) {
     int32_t status = 0;
-    hal::SetLastErrorIndexOutOfRange(&status, "Invalid Index for I2C", 0, 0,
+    hal::SetLastErrorIndexOutOfRange(&status, "Invalid Index for I2C", 0, 1,
                                      port);
     return -1;
   }
@@ -86,15 +95,15 @@ int32_t HAL_TransactionI2C(HAL_I2CPort port, int32_t deviceAddress,
   rdwr.msgs = msgs;
   rdwr.nmsgs = 2;
 
-  std::scoped_lock lock(digitalI2COnBoardMutex);
-  return ioctl(i2COnBoardHandle, I2C_RDWR, &rdwr);
+  std::scoped_lock lock(i2cObjs[port].initMutex);
+  return ioctl(i2cObjs[port].fd, I2C_RDWR, &rdwr);
 }
 
 int32_t HAL_WriteI2C(HAL_I2CPort port, int32_t deviceAddress,
                      const uint8_t* dataToSend, int32_t sendSize) {
-  if (port != 0) {
+  if (port < 0 || port > 2) {
     int32_t status = 0;
-    hal::SetLastErrorIndexOutOfRange(&status, "Invalid Index for I2C", 0, 0,
+    hal::SetLastErrorIndexOutOfRange(&status, "Invalid Index for I2C", 0, 2,
                                      port);
     return -1;
   }
@@ -109,15 +118,15 @@ int32_t HAL_WriteI2C(HAL_I2CPort port, int32_t deviceAddress,
   rdwr.msgs = &msg;
   rdwr.nmsgs = 1;
 
-  std::scoped_lock lock(digitalI2COnBoardMutex);
-  return ioctl(i2COnBoardHandle, I2C_RDWR, &rdwr);
+  std::scoped_lock lock(i2cObjs[port].initMutex);
+  return ioctl(i2cObjs[port].fd, I2C_RDWR, &rdwr);
 }
 
 int32_t HAL_ReadI2C(HAL_I2CPort port, int32_t deviceAddress, uint8_t* buffer,
                     int32_t count) {
-  if (port != 0) {
+  if (port < 0 || port > 2) {
     int32_t status = 0;
-    hal::SetLastErrorIndexOutOfRange(&status, "Invalid Index for I2C", 0, 0,
+    hal::SetLastErrorIndexOutOfRange(&status, "Invalid Index for I2C", 0, 1,
                                      port);
     return -1;
   }
@@ -132,21 +141,22 @@ int32_t HAL_ReadI2C(HAL_I2CPort port, int32_t deviceAddress, uint8_t* buffer,
   rdwr.msgs = &msg;
   rdwr.nmsgs = 1;
 
-  std::scoped_lock lock(digitalI2COnBoardMutex);
-  return ioctl(i2COnBoardHandle, I2C_RDWR, &rdwr);
+  std::scoped_lock lock(i2cObjs[port].initMutex);
+  return ioctl(i2cObjs[port].fd, I2C_RDWR, &rdwr);
 }
 
 void HAL_CloseI2C(HAL_I2CPort port) {
-  if (port != 0) {
+  if (port < 0 || port > 2) {
     int32_t status = 0;
-    hal::SetLastErrorIndexOutOfRange(&status, "Invalid Index for I2C", 0, 0,
+    hal::SetLastErrorIndexOutOfRange(&status, "Invalid Index for I2C", 0, 1,
                                      port);
     return;
   }
 
-  std::scoped_lock lock(digitalI2COnBoardMutex);
-  if (i2COnboardObjCount-- == 0) {
-    close(i2COnBoardHandle);
+  std::scoped_lock lock(i2cObjs[port].initMutex);
+  if (i2cObjs[port].objCount-- == 0) {
+    close(i2cObjs[port].objCount);
+    i2cObjs[port].fd = -1;
   }
 }
 

hal/src/main/native/systemcore/PortsInternal.h

@@ -10,6 +10,7 @@ namespace hal {
 
 constexpr int32_t kNumCanBuses = 5;
 constexpr int32_t kNumSmartIo = 6;
+constexpr int32_t kNumI2cBuses = 2;
 constexpr int32_t kNumAccumulators = 0;
 constexpr int32_t kNumAnalogInputs = 8;
 constexpr int32_t kNumAnalogOutputs = 0;

hal/src/test/native/cpp/mockdata/I2CDataTest.cpp

@@ -31,7 +31,7 @@ TEST(I2CSimTest, I2CInitialization) {
       INDEX_TO_TEST, &TestI2CInitializationCallback, &callbackParam, false);
   ASSERT_TRUE(0 != callbackId);
 
-  port = HAL_I2C_kMXP;
+  port = HAL_I2C_kPort1;
   gTestI2CCallbackName = "Unset";
   HAL_InitializeI2C(port, &status);
   EXPECT_STREQ("Initialized", gTestI2CCallbackName.c_str());

wpilibc/src/main/native/include/frc/I2C.h

@@ -23,10 +23,10 @@ class I2C {
    * I2C connection ports.
    */
   enum Port {
-    /// Onboard I2C port.
-    kOnboard = 0,
-    /// MXP (roboRIO MXP) I2C port.
-    kMXP
+    /// I2C Port 0.
+    kPort0 = 0,
+    /// I2C Port 1.
+    kPort1
   };
 
   /**

wpilibcExamples/src/main/cpp/examples/I2CCommunication/include/Robot.h

@@ -17,7 +17,7 @@ class Robot : public frc::TimedRobot {
  public:
   void RobotPeriodic() override;
 
-  static constexpr frc::I2C::Port kPort = frc::I2C::Port::kOnboard;
+  static constexpr frc::I2C::Port kPort = frc::I2C::Port::kPort0;
 
  private:
   static constexpr int deviceAddress = 4;

wpilibj/src/main/java/edu/wpi/first/wpilibj/I2C.java

@@ -20,10 +20,10 @@ import java.nio.ByteBuffer;
 public class I2C implements AutoCloseable {
   /** I2C connection ports. */
   public enum Port {
-    /** Onboard I2C port. */
-    kOnboard(0),
-    /** MXP (roboRIO MXP) I2C port. */
-    kMXP(1);
+    /** I2C Port 0. */
+    kPort0(0),
+    /** I2C Port 1. */
+    kPort1(1);
 
     /** Port value. */
     public final int value;

wpilibj/src/test/java/edu/wpi/first/wpilibj/simulation/ADXL345SimTest.java

@@ -18,7 +18,7 @@ class ADXL345SimTest {
   void testInitI2C(ADXL345_I2C.Range range) {
     HAL.initialize(500, 0);
 
-    try (ADXL345_I2C accel = new ADXL345_I2C(I2C.Port.kMXP, range)) {
+    try (ADXL345_I2C accel = new ADXL345_I2C(I2C.Port.kPort0, range)) {
       ADXL345Sim sim = new ADXL345Sim(accel);
 
       sim.setX(1.91);

wpilibjExamples/src/main/java/edu/wpi/first/wpilibj/examples/i2ccommunication/Robot.java

@@ -15,7 +15,7 @@ import java.util.Optional;
  * code using the roboRIO's I2C port.
  */
 public class Robot extends TimedRobot {
-  static final Port kPort = Port.kOnboard;
+  static final Port kPort = Port.kPort0;
   private static final int kDeviceAddress = 4;
 
   private final I2C m_arduino = new I2C(kPort, kDeviceAddress);