reading EDID information from display and submission to host works

1 files changed, 160 insertions, 80 deletions

diff --git a/twi_master_driver.c b/twi_master_driver.c
index c7f9695..8c5a695 100644
--- a/twi_master_driver.c
+++ b/twi_master_driver.c
@@ -68,6 +68,10 @@
 

 #include "twi_master_driver.h"

 

+static void TWI_MasterWriteHandler(TWI_Master_t *twi);

+static void TWI_MasterReadHandler(TWI_Master_t *twi);

+static void TWI_MasterTransactionFinished(TWI_Master_t *twi, uint8_t result);

+static void TWI_MasterArbitrationLostBusErrorHandler(TWI_Master_t *twi);

 

 /*! \brief Initialize the TWI module.

  *

@@ -86,14 +90,28 @@ void TWI_MasterInit(TWI_Master_t *twi,
                     uint8_t baudRateRegisterSetting)

 {

 	twi->interface = module;

+	twi->interface->CTRL = TWI_SDAHOLD_bm;

 	twi->interface->MASTER.CTRLA = intLevel |

 	                               TWI_MASTER_RIEN_bm |

 	                               TWI_MASTER_WIEN_bm |

 	                               TWI_MASTER_ENABLE_bm;

+

+	#if 1

+	twi->interface->MASTER.CTRLB =

+		TWI_MASTER_TIMEOUT_200US_gc;

+	#endif

+

 	twi->interface->MASTER.BAUD = baudRateRegisterSetting;

 	twi->interface->MASTER.STATUS = TWI_MASTER_BUSSTATE_IDLE_gc;

+

+	twi->status = TWIM_STATUS_READY;

 }

 

+void TWI_MasterForceIdle(TWI_Master_t *twi)

+{

+	twi->interface->MASTER.STATUS = TWI_MASTER_BUSSTATE_IDLE_gc;

+	twi->status = TWIM_STATUS_READY;

+}

 

 /*! \brief Returns the TWI bus state.

  *

@@ -128,7 +146,7 @@ TWI_MASTER_BUSSTATE_t TWI_MasterState(TWI_Master_t *twi)
  */

 bool TWI_MasterReady(TWI_Master_t *twi)

 {

-	bool twi_status = (twi->status & TWIM_STATUS_READY);

+	bool twi_status = (twi->status == TWIM_STATUS_READY);

 	return twi_status;

 }

 

@@ -147,10 +165,14 @@ bool TWI_MasterReady(TWI_Master_t *twi)
  */

 bool TWI_MasterWrite(TWI_Master_t *twi,

                      uint8_t address,

-                     uint8_t *writeData,

+                     uint8_t const *writeData,

                      uint8_t bytesToWrite)

 {

-	bool twi_status = TWI_MasterWriteRead(twi, address, writeData, bytesToWrite, 0);

+	bool twi_status = TWI_MasterWriteRead(twi,

+		address,

+		writeData, bytesToWrite,

+		NULL, 0);

+

 	return twi_status;

 }

 

@@ -168,9 +190,14 @@ bool TWI_MasterWrite(TWI_Master_t *twi,
  */

 bool TWI_MasterRead(TWI_Master_t *twi,

                     uint8_t address,

+		    uint8_t *readData,

                     uint8_t bytesToRead)

 {

-	bool twi_status = TWI_MasterWriteRead(twi, address, 0, 0, bytesToRead);

+	bool twi_status = TWI_MasterWriteRead(twi,

+		address,

+		NULL, 0,

+		readData, bytesToRead);

+

 	return twi_status;

 }

 

@@ -192,55 +219,57 @@ bool TWI_MasterRead(TWI_Master_t *twi,
  */

 bool TWI_MasterWriteRead(TWI_Master_t *twi,

                          uint8_t address,

-                         uint8_t *writeData,

+                         uint8_t const *writeData,

                          uint8_t bytesToWrite,

+			 uint8_t *readData,

                          uint8_t bytesToRead)

 {

-	/*Parameter sanity check. */

-	if (bytesToWrite > TWIM_WRITE_BUFFER_SIZE) {

-		return false;

+	if( !bytesToWrite || !writeData ) {

+		writeData = NULL;

+		bytesToWrite = 0;

 	}

-	if (bytesToRead > TWIM_READ_BUFFER_SIZE) {

-		return false;

+	if( !bytesToRead || !readData ) {

+		readData = NULL;

+		bytesToRead = 0;

 	}

 

 	/*Initiate transaction if bus is ready. */

-	if (twi->status == TWIM_STATUS_READY) {

-

-		twi->status = TWIM_STATUS_BUSY;

-		twi->result = TWIM_RESULT_UNKNOWN;

-

-		twi->address = address<<1;

-

-		/* Fill write data buffer. */

-		for (uint8_t bufferIndex=0; bufferIndex < bytesToWrite; bufferIndex++) {

-			twi->writeData[bufferIndex] = writeData[bufferIndex];

-		}

-

-		twi->bytesToWrite = bytesToWrite;

-		twi->bytesToRead = bytesToRead;

-		twi->bytesWritten = 0;

-		twi->bytesRead = 0;

-

-		/* If write command, send the START condition + Address +

-		 * 'R/_W = 0'

-		 */

-		if (twi->bytesToWrite > 0) {

-			uint8_t writeAddress = twi->address & ~0x01;

-			twi->interface->MASTER.ADDR = writeAddress;

-		}

-

-		/* If read command, send the START condition + Address +

-		 * 'R/_W = 1'

-		 */

-		else if (twi->bytesToRead > 0) {

-			uint8_t readAddress = twi->address | 0x01;

-			twi->interface->MASTER.ADDR = readAddress;

-		}

-		return true;

-	} else {

+	if( twi->status != TWIM_STATUS_READY ) {

 		return false;

 	}

+

+	twi->status = TWIM_STATUS_BUSY;

+	twi->result = TWIM_RESULT_UNKNOWN;

+

+	twi->address = (address << 1);

+

+	twi->writeData = writeData;

+	twi->readData = readData;

+	twi->bytesToWrite = bytesToWrite;

+	twi->bytesToRead = bytesToRead;

+	twi->bytesWritten = 0;

+	twi->bytesRead = 0;

+

+	/* If write command, send the START condition + Address +

+	 * 'R/_W = 0'

+	 */

+	if( twi->bytesToWrite > 0 ) {

+		uint8_t const writeAddress = twi->address & ~0x01;

+		twi->interface->MASTER.ADDR = writeAddress;

+

+		uint8_t const data = twi->writeData[0];

+		twi->interface->MASTER.DATA = data;

+		twi->bytesWritten++;

+	} else

+	/* If read command, send the START condition + Address +

+	 * 'R/_W = 1'

+	 */

+	if( twi->bytesToRead > 0 ) {

+		uint8_t const readAddress = twi->address | 0x01;

+		twi->interface->MASTER.ADDR = readAddress;

+	}

+	

+	return true;

 }

 

 

@@ -252,28 +281,64 @@ bool TWI_MasterWriteRead(TWI_Master_t *twi,
  */

 void TWI_MasterInterruptHandler(TWI_Master_t *twi)

 {

-	uint8_t currentStatus = twi->interface->MASTER.STATUS;

+#if 0

+	PORTB.OUTSET = (1<<3);

+	PORTB.OUTCLR = (1<<3);

+#endif

+	uint8_t const currentStatus = twi->interface->MASTER.STATUS;

 

 	/* If arbitration lost or bus error. */

 	if ((currentStatus & TWI_MASTER_ARBLOST_bm) ||

 	    (currentStatus & TWI_MASTER_BUSERR_bm)) {

+#if 0

+	PORTB.OUTSET = (1<<3);

+	PORTB.OUTCLR = (1<<3);

+#endif

 

 		TWI_MasterArbitrationLostBusErrorHandler(twi);

-	}

-

+		twi->interface->MASTER.STATUS =

+			  currentStatus

+			| TWI_MASTER_ARBLOST_bm

+			| TWI_MASTER_BUSERR_bm;

+	} else

 	/* If master write interrupt. */

-	else if (currentStatus & TWI_MASTER_WIF_bm) {

+	if (currentStatus & TWI_MASTER_WIF_bm) {

+#if 0

+	PORTB.OUTSET = (1<<3);

+	PORTB.OUTCLR = (1<<3);

+#endif

 		TWI_MasterWriteHandler(twi);

-	}

 

+		twi->interface->MASTER.STATUS =

+			  currentStatus

+			| TWI_MASTER_WIF_bm;

+	} else

 	/* If master read interrupt. */

-	else if (currentStatus & TWI_MASTER_RIF_bm) {

+	if (currentStatus & TWI_MASTER_RIF_bm) {

+#if 0

+	PORTB.OUTSET = (1<<3);

+	PORTB.OUTCLR = (1<<3);

+#endif

 		TWI_MasterReadHandler(twi);

-	}

 

+		twi->interface->MASTER.STATUS =

+			  currentStatus

+			| TWI_MASTER_RIF_bm;

+	} else 

+	/* Bus went idle (timeout) */

+	if( (currentStatus & TWI_MASTER_BUSSTATE_IDLE_gc)

+	    == TWI_MASTER_BUSSTATE_IDLE_gc ) {

+		TWI_MasterTransactionFinished(twi, TWIM_RESULT_UNKNOWN);

+	}

 	/* If unexpected state. */

 	else {

+#if 0

+	PORTB.OUTSET = (1<<3);

+	PORTB.OUTCLR = (1<<3);

+#endif

 		TWI_MasterTransactionFinished(twi, TWIM_RESULT_FAIL);

+

+		twi->interface->MASTER.STATUS = currentStatus;

 	}

 }

 

@@ -284,9 +349,9 @@ void TWI_MasterInterruptHandler(TWI_Master_t *twi)
  *

  *  \param twi  The TWI_Master_t struct instance.

  */

-void TWI_MasterArbitrationLostBusErrorHandler(TWI_Master_t *twi)

+static void TWI_MasterArbitrationLostBusErrorHandler(TWI_Master_t *twi)

 {

-	uint8_t currentStatus = twi->interface->MASTER.STATUS;

+	uint8_t const currentStatus = twi->interface->MASTER.STATUS;

 

 	/* If bus error. */

 	if (currentStatus & TWI_MASTER_BUSERR_bm) {

@@ -297,9 +362,6 @@ void TWI_MasterArbitrationLostBusErrorHandler(TWI_Master_t *twi)
 		twi->result = TWIM_RESULT_ARBITRATION_LOST;

 	}

 

-	/* Clear interrupt flag. */

-	twi->interface->MASTER.STATUS = currentStatus | TWI_MASTER_ARBLOST_bm;

-

 	twi->status = TWIM_STATUS_READY;

 }

 

@@ -310,36 +372,49 @@ void TWI_MasterArbitrationLostBusErrorHandler(TWI_Master_t *twi)
  *

  *  \param twi The TWI_Master_t struct instance.

  */

-void TWI_MasterWriteHandler(TWI_Master_t *twi)

+static void TWI_MasterWriteHandler(TWI_Master_t *twi)

 {

 	/* Local variables used in if tests to avoid compiler warning. */

-	uint8_t bytesToWrite  = twi->bytesToWrite;

-	uint8_t bytesToRead   = twi->bytesToRead;

+	uint8_t const bytesToWrite  = twi->bytesToWrite;

+	uint8_t const bytesToRead   = twi->bytesToRead;

 

 	/* If NOT acknowledged (NACK) by slave cancel the transaction. */

-	if (twi->interface->MASTER.STATUS & TWI_MASTER_RXACK_bm) {

+	if( twi->interface->MASTER.STATUS & TWI_MASTER_RXACK_bm ) {

+#if 0

+	PORTB.OUTSET = (1<<3);

+	PORTB.OUTCLR = (1<<3);

+#endif

 		twi->interface->MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;

 		twi->result = TWIM_RESULT_NACK_RECEIVED;

 		twi->status = TWIM_STATUS_READY;

-	}

-

+	} else

 	/* If more bytes to write, send data. */

-	else if (twi->bytesWritten < bytesToWrite) {

-		uint8_t data = twi->writeData[twi->bytesWritten];

+	if( twi->bytesWritten < bytesToWrite ) {

+#if 0

+	PORTB.OUTSET = (1<<3);

+	PORTB.OUTCLR = (1<<3);

+#endif

+		uint8_t const data = twi->writeData[twi->bytesWritten];

 		twi->interface->MASTER.DATA = data;

-		++twi->bytesWritten;

-	}

-

+		twi->bytesWritten++;

+	} else

 	/* If bytes to read, send repeated START condition + Address +

 	 * 'R/_W = 1'

 	 */

-	else if (twi->bytesRead < bytesToRead) {

-		uint8_t readAddress = twi->address | 0x01;

+	if( twi->bytesRead < bytesToRead ) {

+#if 0

+	PORTB.OUTSET = (1<<3);

+	PORTB.OUTCLR = (1<<3);

+#endif

+		uint8_t const readAddress = twi->address | 0x01;

 		twi->interface->MASTER.ADDR = readAddress;

 	}

-

 	/* If transaction finished, send STOP condition and set RESULT OK. */

 	else {

+#if 0

+	PORTB.OUTSET = (1<<3);

+	PORTB.OUTCLR = (1<<3);

+#endif

 		twi->interface->MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;

 		TWI_MasterTransactionFinished(twi, TWIM_RESULT_OK);

 	}

@@ -353,32 +428,36 @@ void TWI_MasterWriteHandler(TWI_Master_t *twi)
  *

  *  \param twi The TWI_Master_t struct instance.

  */

-void TWI_MasterReadHandler(TWI_Master_t *twi)

+static void TWI_MasterReadHandler(TWI_Master_t *twi)

 {

+#if 1

+	PORTB.OUTTGL = (1<<3);

+	PORTB.OUTTGL = (1<<3);

+#endif

+

+	/* Local variable used in if test to avoid compiler warning. */

+	uint8_t const bytesToRead = twi->bytesToRead;

+

 	/* Fetch data if bytes to be read. */

-	if (twi->bytesRead < TWIM_READ_BUFFER_SIZE) {

-		uint8_t data = twi->interface->MASTER.DATA;

+	if( twi->bytesRead < bytesToRead ) {

+		uint8_t const data = twi->interface->MASTER.DATA;

 		twi->readData[twi->bytesRead] = data;

 		twi->bytesRead++;

 	}

-

 	/* If buffer overflow, issue STOP and BUFFER_OVERFLOW condition. */

 	else {

 		twi->interface->MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;

 		TWI_MasterTransactionFinished(twi, TWIM_RESULT_BUFFER_OVERFLOW);

 	}

 

-	/* Local variable used in if test to avoid compiler warning. */

-	uint8_t bytesToRead = twi->bytesToRead;

-

 	/* If more bytes to read, issue ACK and start a byte read. */

-	if (twi->bytesRead < bytesToRead) {

+	if( twi->bytesRead < bytesToRead ) {

 		twi->interface->MASTER.CTRLC = TWI_MASTER_CMD_RECVTRANS_gc;

 	}

 

 	/* If transaction finished, issue NACK and STOP condition. */

 	else {

-		twi->interface->MASTER.CTRLC = TWI_MASTER_ACKACT_bm |

+		twi->interface->MASTER.CTRLC = //TWI_MASTER_ACKACT_bm |

 		                               TWI_MASTER_CMD_STOP_gc;

 		TWI_MasterTransactionFinished(twi, TWIM_RESULT_OK);

 	}

@@ -392,8 +471,9 @@ void TWI_MasterReadHandler(TWI_Master_t *twi)
  *  \param twi     The TWI_Master_t struct instance.

  *  \param result  The result of the operation.

  */

-void TWI_MasterTransactionFinished(TWI_Master_t *twi, uint8_t result)

+static void TWI_MasterTransactionFinished(TWI_Master_t *twi, uint8_t result)

 {

 	twi->result = result;

 	twi->status = TWIM_STATUS_READY;

 }

+