lpc177x_8x_i2c.c

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				if (TransferCfg->retransmissions_count > TransferCfg->retransmissions_max)
				{
					// save status
					TransferCfg->status = CodeStatus | I2C_SETUP_STATUS_NOACKF;

					goto error;
				}
				else
				{
					goto retry;
				}
			}

			/* Send a number of data bytes ---------------------------------------- */
			while (TransferCfg->tx_count < TransferCfg->tx_length)
			{
				CodeStatus = I2C_SendByte(I2Cx, *txdat);   //发送数据

				if (CodeStatus != I2C_I2STAT_M_TX_DAT_ACK)
				{
					TransferCfg->retransmissions_count++;

					if (TransferCfg->retransmissions_count > TransferCfg->retransmissions_max)
					{
						// save status
						TransferCfg->status = CodeStatus | I2C_SETUP_STATUS_NOACKF;

						goto error;
					}
					else
					{
						goto retry;
					}
				}

				txdat++;

				TransferCfg->tx_count++;
			}
		}
#if 0
		/* Second Start condition (Repeat Start) ------------------------------------------- */
		if ((TransferCfg->tx_length != 0) && (TransferCfg->tx_data != NULL) \
				&& (TransferCfg->rx_length != 0) && (TransferCfg->rx_data != NULL))
		{
			CodeStatus = I2C_Start(I2Cx);

			if ((CodeStatus != I2C_I2STAT_M_RX_START) \
					&& (CodeStatus != I2C_I2STAT_M_RX_RESTART))
			{
				TransferCfg->retransmissions_count++;

				if (TransferCfg->retransmissions_count > TransferCfg->retransmissions_max)
				{
					// Update status
					TransferCfg->status = CodeStatus;
					goto error;
				}
				else
				{
					goto retry;
				}
			}
		}
#endif
		/* Then, start reading after sending data -------------------------------------- */
		if ((TransferCfg->rx_length != 0) && (TransferCfg->rx_data != NULL))
		{
			I2C_Stop(I2Cx);		   //发送停止位
			CodeStatus = I2C_Start(I2Cx);

			if ((CodeStatus != I2C_I2STAT_M_RX_START) \
					&& (CodeStatus != I2C_I2STAT_M_RX_RESTART))
			{
				TransferCfg->retransmissions_count++;

				if (TransferCfg->retransmissions_count > TransferCfg->retransmissions_max)
				{
					// Update status
					TransferCfg->status = CodeStatus;
					goto error;
				}
				else
				{
					goto retry;
				}
			}

			/* Send slave address + RD direction bit = 1 ----------------------------------- */

			CodeStatus = I2C_SendByte(I2Cx, ((TransferCfg->sl_addr7bit << 1) | 0x01));

			if (CodeStatus != I2C_I2STAT_M_RX_SLAR_ACK)
			{
				TransferCfg->retransmissions_count++;

				if (TransferCfg->retransmissions_count > TransferCfg->retransmissions_max)
				{
					// update status
					TransferCfg->status = CodeStatus | I2C_SETUP_STATUS_NOACKF;

					goto error;
				}
				else
				{
					goto retry;
				}
			}

			/* Receive a number of data bytes ------------------------------------------------- */
			while (TransferCfg->rx_count < TransferCfg->rx_length)
			{
				/*
				 * Note that: if data length is only one, the master should not
				 * issue an ACK signal on bus after reading to avoid of next data frame
				 * on slave side
				 */
				if (TransferCfg->rx_count < (TransferCfg->rx_length - 1))
				{
					// Issue an ACK signal for next data frame
					CodeStatus = I2C_GetByte(I2Cx, &tmp, 1);

					if (CodeStatus != I2C_I2STAT_M_RX_DAT_ACK)
					{
						TransferCfg->retransmissions_count++;

						if (TransferCfg->retransmissions_count > TransferCfg->retransmissions_max)
						{
							// update status
							TransferCfg->status = CodeStatus;

							goto error;
						}
						else
						{
							goto retry;
						}
					}
				}
				else
				{
					// Do not issue an ACK signal
					CodeStatus = I2C_GetByte(I2Cx, &tmp, 0);

					if (CodeStatus != I2C_I2STAT_M_RX_DAT_NACK)
					{
						TransferCfg->retransmissions_count++;

						if (TransferCfg->retransmissions_count > TransferCfg->retransmissions_max)
						{
							// update status
							TransferCfg->status = CodeStatus;

							goto error;
						}
						else
						{
							goto retry;
						}
					}
				}

				*rxdat++ = tmp;

				TransferCfg->rx_count++;
			}
		}

		/* Send STOP condition ------------------------------------------------- */
		I2C_Stop(I2Cx);

		return SUCCESS;

error:
		// Send stop condition
		I2C_Stop(I2Cx);

		return ERROR;
	}

	else if (Opt == I2C_TRANSFER_INTERRUPT)
	{
		// Setup tx_rx data, callback and interrupt handler
		i2cdat[i2cId].txrx_setup = (uint32_t) TransferCfg;

		// Set direction phase, write first
		i2cdat[i2cId].dir = 0;

		/* First Start condition -------------------------------------------------------------- */
		I2Cx->CONCLR = I2C_I2CONCLR_SIC;
		I2Cx->CONSET = I2C_I2CONSET_STA;

		I2C_IntCmd(i2cId, 1);

		return (SUCCESS);
	}

	return ERROR;
}

/*********************************************************************//**
 * @brief 		Receive and Transmit data in slave mode
 * @param[in]	I2Cx			I2C peripheral selected, should be
 *    			- LPC_I2C0
 * 				- LPC_I2C1
 * 				- LPC_I2C2
 * @param[in]	TransferCfg		Pointer to a I2C_S_SETUP_Type structure that
 * 								contains specified information about the
 * 								configuration for master transfer.
 * @param[in]	Opt				I2C_TRANSFER_OPT_Type type that selected for
 * 								interrupt or polling mode.
 * @return 		SUCCESS or ERROR
 *
 * Note:
 * The mode of slave's operation depends on the command sent from master on
 * the I2C bus. If the master send a SLA+W command, this sub-routine will
 * use receive data length and receive data pointer. If the master send a SLA+R
 * command, this sub-routine will use transmit data length and transmit data
 * pointer.
 * If the master issue an repeat start command or a stop command, the slave will
 * enable an time out condition, during time out condition, if there's no activity
 * on I2C bus, the slave will exit, otherwise (i.e. the master send a SLA+R/W),
 * the slave then switch to relevant operation mode. The time out should be used
 * because the return status code can not show difference from stop and repeat
 * start command in slave operation.
 * In case of the expected data length from master is greater than data length
 * that slave can support:
 * - In case of reading operation (from master): slave will return I2C_I2DAT_IDLE_CHAR
 * value.
 * - In case of writing operation (from master): slave will ignore remain data from master.
 **********************************************************************/
Status I2C_SlaveTransferData(uint8_t i2cId, I2C_S_SETUP_Type *TransferCfg,
																	I2C_TRANSFER_OPT_Type Opt)
{
	LPC_I2C_TypeDef* I2Cx = I2C_GetPointer(i2cId);

	uint8_t *txdat;
	uint8_t *rxdat;
	uint32_t CodeStatus;
	uint32_t timeout;
	int32_t time_en;

	// reset all default state
	txdat = (uint8_t *) TransferCfg->tx_data;
	rxdat = (uint8_t *) TransferCfg->rx_data;
	// Reset I2C setup value to default state
	TransferCfg->tx_count = 0;
	TransferCfg->rx_count = 0;
	TransferCfg->status = 0;


	// Polling option
	if (Opt == I2C_TRANSFER_POLLING)
	{
		/* Set AA bit to ACK command on I2C bus */
		I2Cx->CONSET = I2C_I2CONSET_AA;

		/* Clear SI bit to be ready ... */
		I2Cx->CONCLR = (I2C_I2CONCLR_SIC | I2C_I2CONCLR_STAC);

		time_en = 0;
		timeout = 0;

		while (1)
		{
			/* Check SI flag ready */
			if (I2Cx->CONSET & I2C_I2CONSET_SI)
			{
				time_en = 0;

				switch (CodeStatus = (I2Cx->STAT & I2C_STAT_CODE_BITMASK))
				{
					/* No status information */
					case I2C_I2STAT_NO_INF:
						I2Cx->CONSET = I2C_I2CONSET_AA;
						I2Cx->CONCLR = I2C_I2CONCLR_SIC;
						break;

					/* Reading phase -------------------------------------------------------- */
					/* Own SLA+R has been received, ACK has been returned */
					case I2C_I2STAT_S_RX_SLAW_ACK:

					/* General call address has been received, ACK has been returned */
					case I2C_I2STAT_S_RX_GENCALL_ACK:
						I2Cx->CONSET = I2C_I2CONSET_AA;
						I2Cx->CONCLR = I2C_I2CONCLR_SIC;
						break;

					/* Previously addressed with own SLA;
					 * DATA byte has been received;
					 * ACK has been returned */
					case I2C_I2STAT_S_RX_PRE_SLA_DAT_ACK:

					/* DATA has been received, ACK hasn been return */
					case I2C_I2STAT_S_RX_PRE_GENCALL_DAT_ACK:
						/*
						 * All data bytes that over-flow the specified receive
						 * data length, just ignore them.
						 */
						if ((TransferCfg->rx_count < TransferCfg->rx_length) && (TransferCfg->rx_data != NULL))
						{
							*rxdat++ = (uint8_t)I2Cx->DAT;

							TransferCfg->rx_count++;
						}

						I2Cx->CONSET = I2C_I2CONSET_AA;
						I2Cx->CONCLR = I2C_I2CONCLR_SIC;
						break;

					/* Previously addressed with own SLA;
					 * DATA byte has been received;
					 * NOT ACK has been returned */
					case I2C_I2STAT_S_RX_PRE_SLA_DAT_NACK:

					/* DATA has been received, NOT ACK has been returned */
					case I2C_I2STAT_S_RX_PRE_GENCALL_DAT_NACK:
						I2Cx->CONCLR = I2C_I2CONCLR_SIC;
						break;

					/*
					 * Note that: Return code only let us know a stop condition mixed
					 * with a repeat start condition in the same code value.
					 * So we should provide a time-out. In case this is really a stop
					 * condition, this will return back after time out condition. Otherwise,
					 * next session that is slave receive data will be completed.
					 */

					/* A Stop or a repeat start condition */
					case I2C_I2STAT_S_RX_STA_STO_SLVREC_SLVTRX:
						I2Cx->CONCLR = I2C_I2CONCLR_SIC;
						// enable time out
						time_en = 1;
						timeout = 0;
						break;

					/* Writing phase -------------------------------------------------------- */
					/* Own SLA+R has been received, ACK has been returned */
					case I2C_I2STAT_S_TX_SLAR_ACK:

					/* Data has been transmitted, ACK has been received */
					case I2C_I2STAT_S_TX_DAT_ACK:
						/*
						 * All data bytes that over-flow the specified receive
						 * data length, just ignore them.
						 */
						if ((TransferCfg->tx_count < TransferCfg->tx_length) && (TransferCfg->tx_data != NULL))
						{
							I2Cx->DAT = *txdat++;

							TransferCfg->tx_count++;
						}

						I2Cx->CONSET = I2C_I2CONSET_AA;
						I2Cx->CONCLR = I2C_I2CONCLR_SIC;
						break;

					/* Data has been transmitted, NACK has been received,
					 * that means there's no more data to send, exit now */
					/*
					 * Note: Don't wait for stop event since in slave transmit mode,
					 * since there no proof lets us know when a stop signal has been received
					 * on slave side.
					 */
					case I2C_I2STAT_S_TX_DAT_NACK:
						I2Cx->CONSET = I2C_I2CONSET_AA;
						I2Cx->CONCLR = I2C_I2CONCLR_SIC;
						// enable time out
						time_en = 1;
						timeout = 0;
						break;

					// Other status must be captured
					default:
						I2Cx->CONCLR = I2C_I2CONCLR_SIC;
						goto s_error;
				}
			}
			else if (time_en)
			{
				if (timeout++ > I2C_SLAVE_TIME_OUT)
				{
					// it's really a stop condition, goto end stage
					goto s_end_stage;
				}
			}
		}

s_end_stage:
		/* Clear AA bit to disable ACK on I2C bus */
		I2Cx->CONCLR = I2C_I2CONCLR_AAC;

		// Check if there's no error during operation
		// Update status
		TransferCfg->status = CodeStatus | I2C_SETUP_STATUS_DONE;
		return SUCCESS;

s_error:
		/* Clear AA bit to disable ACK on I2C bus */
		I2Cx->CONCLR = I2C_I2CONCLR_AAC;

		// Update status
		TransferCfg->status = CodeStatus;
		return ERROR;
	}

	else if (Opt == I2C_TRANSFER_INTERRUPT)
	{
		// Setup tx_rx data, callback and interrupt handler
		i2cdat[i2cId].txrx_setup = (uint32_t) TransferCfg;

		// Set direction phase, read first
		i2cdat[i2cId].dir = 1;

		// Enable AA
		I2Cx->CONSET = I2C_I2CONSET_AA;
		I2Cx->CONCLR = I2C_I2CONCLR_SIC | I2C_I2CONCLR_STAC;
		I2C_IntCmd(i2cId, 1);

		return (SUCCESS);
	}

	return ERROR;
}

/*********************************************************************//**
 * @brief		Set Own slave address in I2C peripheral corresponding to
 * 				parameter specified in OwnSlaveAddrConfigStruct.
 * @param[in]	I2Cx	I2C peripheral selected, should be
 *    			- LPC_I2C0
 * 				- LPC_I2C1
 * 				- LPC_I2C2
 * @param[in]	OwnSlaveAddrConfigStruct	Pointer to a I2C_OWNSLAVEADDR_CFG_Type
 * 				structure that contains the configuration information for the
*               specified I2C slave address.
 * @return 		None
 **********************************************************************/
void I2C_SetOwnSlaveAddr(uint8_t i2cId, I2C_OWNSLAVEADDR_CFG_Type *OwnSlaveAddrConfigStruct)
{
	LPC_I2C_TypeDef* I2Cx = I2C_GetPointer(i2cId);

	uint32_t tmp;

	tmp = (((uint32_t)(OwnSlaveAddrConfigStruct->SlaveAddr_7bit << 1)) \