/**
* \copyright
* Copyright(c) 2018, Infineon Technologies AG
* All rights reserved.
*
* This software is provided with terms and conditions as specified in OPTIGA(TM) Trust X Evaluation Kit License Agreement.
* \endcopyright
*
* \author Infineon AG
*
* \file
*
* \brief This file implements the platform abstraction layer(pal) APIs for I2C.
*
* \addtogroup grPAL
* @{
*/
/**********************************************************************************************************************
* HEADER FILES
*********************************************************************************************************************/
#include "pal_i2c.h"
#include "ifx_i2c.h"
#include "nrf_twi_mngr.h"
/// @cond hidden
/**********************************************************************************************************************
* MACROS
*********************************************************************************************************************/
#define PAL_I2C_MASTER_MAX_BITRATE (400)
/** @brief PIN for I2C SCL to Infineon OPTIGA Trust X device */
#define OPTIGA_PIN_I2C_SCL (27)
/** @brief PIN for I2C SDA to Infineon OPTIGA Trust X device */
#define OPTIGA_PIN_I2C_SDA (26)
/** @brief I2C driver instance */
#define TWI_INSTANCE_ID 0
/** @brief Maximal number of pending I2C transactions */
#define MAX_PENDING_TRANSACTIONS 5
/*********************************************************************************************************************
* LOCAL DATA
*********************************************************************************************************************/
/* Pointer to the current pal i2c context */
static pal_i2c_t * gp_pal_i2c_current_ctx;
/** @brief Definition of TWI manager instance */
NRF_TWI_MNGR_DEF(m_app_twi, MAX_PENDING_TRANSACTIONS, TWI_INSTANCE_ID);
/** @brief Definition of TWI manager transfer instance */
static nrf_twi_mngr_transfer_t m_transfer;
/** @brief Definition of TWI manager transaction instance */
static nrf_twi_mngr_transaction_t m_transaction;
/**********************************************************************************************************************
* LOCAL ROUTINES
*********************************************************************************************************************/
/**
* Pal I2C event handler function to invoke the registered upper layer callback
*
*API Details:
* - This function implements the platform specific i2c event handling mechanism
* - It calls the registered upper layer function after completion of the I2C read/write operations
* - The respective event status are explained below.
* - #PAL_I2C_EVENT_ERROR when I2C fails due to low level failures(NACK/I2C protocol errors)
* - #PAL_I2C_EVENT_SUCCESS when operation is successfully completed
*
* \param[in] p_pal_i2c_ctx Pointer to the pal i2c context #pal_i2c_t
* \param[in] event Status of the event reported after read/write completion or due to I2C errors
*
*/
static void app_twi_callback(ret_code_t result, void * p_user_data)
{
app_event_handler_t upper_layer_handler;
//lint --e{611} suppress "void* function pointer is type casted to app_event_handler_t type"
upper_layer_handler = (app_event_handler_t)gp_pal_i2c_current_ctx->upper_layer_event_handler;
if (result == NRF_SUCCESS)
{
upper_layer_handler(gp_pal_i2c_current_ctx->upper_layer_ctx, PAL_I2C_EVENT_SUCCESS);
}
else
{
upper_layer_handler(gp_pal_i2c_current_ctx->upper_layer_ctx, PAL_I2C_EVENT_ERROR);
}
}
/// @endcond
/**********************************************************************************************************************
* API IMPLEMENTATION
*********************************************************************************************************************/
/**
* API to initialize the i2c master with the given context.
*
*
*API Details:
* - The platform specific initialization of I2C master has to be implemented as part of this API, if required.
* - If the target platform does not demand explicit initialization of i2c master
* (Example: If the platform driver takes care of init after the reset), it would not be required to implement.
* - The implementation must take care the following scenarios depending upon the target platform selected.
* - The implementation must handle the acquiring and releasing of the I2C bus before initializing the I2C master to
* avoid interrupting the ongoing slave I2C transactions using the same I2C master.
* - If the I2C bus is in busy state, the API must not initialize and return #PAL_STATUS_I2C_BUSY status.
* - Repeated initialization must be taken care with respect to the platform requirements. (Example: Multiple users/applications
* sharing the same I2C master resource)
*
*User Input:
* - The input #pal_i2c_t p_i2c_context must not be NULL.
*
* \param[in] p_i2c_context Pal i2c context to be initialized
*
* \retval #PAL_STATUS_SUCCESS Returns when the I2C master init it successfull
* \retval #PAL_STATUS_FAILURE Returns when the I2C init fails.
*/
pal_status_t pal_i2c_init(const pal_i2c_t* p_i2c_context)
{
nrf_drv_twi_config_t const config = {
.scl = OPTIGA_PIN_I2C_SCL,
.sda = OPTIGA_PIN_I2C_SDA,
.frequency = (nrf_drv_twi_frequency_t) NRF_TWI_FREQ_400K,
.interrupt_priority = APP_IRQ_PRIORITY_LOWEST,
.clear_bus_init = false
};
// Initialize I2C driver
if (nrf_twi_mngr_init(&m_app_twi, &config) != NRF_SUCCESS)
{
return PAL_STATUS_FAILURE;
}
return PAL_STATUS_SUCCESS;
}
/**
* API to de-initialize the I2C master with the specified context.
*
*
*API Details:
* - The platform specific de-initialization of I2C master has to be implemented as part of this API, if required.
* - If the target platform does not demand explicit de-initialization of i2c master
* (Example: If the platform driver takes care of init after the reset), it would not be required to implement.
* - The implementation must take care the following scenarios depending upon the target platform selected.
* - The implementation must handle the acquiring and releasing of the I2C bus before de-initializing the I2C master to
* avoid interrupting the ongoing slave I2C transactions using the same I2C master.
* - If the I2C bus is in busy state, the API must not de-initialize and return #PAL_STATUS_I2C_BUSY status.
* - This API must ensure that multiple users/applications sharing the same I2C master resource is not impacted.
*
*User Input:
* - The input #pal_i2c_t p_i2c_context must not be NULL.
*
* \param[in] p_i2c_context I2C context to be de-initialized
*
* \retval #PAL_STATUS_SUCCESS Returns when the I2C master de-init it successfull
* \retval #PAL_STATUS_FAILURE Returns when the I2C de-init fails.
*/
pal_status_t pal_i2c_deinit(const pal_i2c_t* p_i2c_context)
{
nrf_twi_mngr_uninit(&m_app_twi);
return PAL_STATUS_SUCCESS;
}
/**
* Platform abstraction layer API to write the data to I2C slave.
*
*
* \image html pal_i2c_write.png "pal_i2c_write()" width=20cm
*
*
*API Details:
* - The API attempts to write if the I2C bus is free, else it returns busy status #PAL_STATUS_I2C_BUSY
* - The bus is released only after the completion of transmission or after completion of error handling.
* - The API invokes the upper layer handler with the respective event status as explained below.
* - #PAL_I2C_EVENT_BUSY when I2C bus in busy state
* - #PAL_I2C_EVENT_ERROR when API fails
* - #PAL_I2C_EVENT_SUCCESS when operation is successfully completed asynchronously
*
*
*User Input:
* - The input #pal_i2c_t p_i2c_context must not be NULL.
* - The upper_layer_event_handler must be initialized in the p_i2c_context before invoking the API.
*
*Notes:
* - Otherwise the below implementation has to be updated to handle different bitrates based on the input context.
* - The caller of this API must take care of the guard time based on the slave's requirement.
*
* \param[in] p_i2c_context Pointer to the pal I2C context #pal_i2c_t
* \param[in] p_data Pointer to the data to be written
* \param[in] length Length of the data to be written
*
* \retval #PAL_STATUS_SUCCESS Returns when the I2C write is invoked successfully
* \retval #PAL_STATUS_FAILURE Returns when the I2C write fails.
* \retval #PAL_STATUS_I2C_BUSY Returns when the I2C bus is busy.
*/
pal_status_t pal_i2c_write(pal_i2c_t* p_i2c_context,uint8_t* p_data , uint16_t length)
{
gp_pal_i2c_current_ctx = p_i2c_context;
m_transfer.p_data = p_data;
m_transfer.length = length;
m_transfer.operation = NRF_TWI_MNGR_WRITE_OP(IFX_I2C_BASE_ADDR);
m_transfer.flags = 0;
m_transaction.callback = app_twi_callback;
m_transaction.number_of_transfers = 1;
m_transaction.p_required_twi_cfg = NULL;
m_transaction.p_transfers = &m_transfer;
m_transaction.p_user_data = (void*) PAL_STATUS_SUCCESS;
if (nrf_twi_mngr_schedule(&m_app_twi, &m_transaction) != NRF_SUCCESS)
{
app_twi_callback(NRF_ERROR_BUSY, 0);
}
return PAL_STATUS_SUCCESS;
}
/**
* Platform abstraction layer API to read the data from I2C slave.
*
*
* \image html pal_i2c_read.png "pal_i2c_read()" width=20cm
*
*API Details:
* - The API attempts to read if the I2C bus is free, else it returns busy status #PAL_STATUS_I2C_BUSY
* - The bus is released only after the completion of reception or after completion of error handling.
* - The API invokes the upper layer handler with the respective event status as explained below.
* - #PAL_I2C_EVENT_BUSY when I2C bus in busy state
* - #PAL_I2C_EVENT_ERROR when API fails
* - #PAL_I2C_EVENT_SUCCESS when operation is successfully completed asynchronously
*
*
*User Input:
* - The input #pal_i2c_t p_i2c_context must not be NULL.
* - The upper_layer_event_handler must be initialized in the p_i2c_context before invoking the API.
*
*Notes:
* - Otherwise the below implementation has to be updated to handle different bitrates based on the input context.
* - The caller of this API must take care of the guard time based on the slave's requirement.
*
* \param[in] p_i2c_context pointer to the PAL i2c context #pal_i2c_t
* \param[in] p_data Pointer to the data buffer to store the read data
* \param[in] length Length of the data to be read
*
* \retval #PAL_STATUS_SUCCESS Returns when the I2C read is invoked successfully
* \retval #PAL_STATUS_FAILURE Returns when the I2C read fails.
* \retval #PAL_STATUS_I2C_BUSY Returns when the I2C bus is busy.
*/
pal_status_t pal_i2c_read(pal_i2c_t* p_i2c_context , uint8_t* p_data , uint16_t length)
{
gp_pal_i2c_current_ctx = p_i2c_context;
m_transfer.p_data = p_data;
m_transfer.length = length;
m_transfer.operation = NRF_TWI_MNGR_READ_OP(IFX_I2C_BASE_ADDR);
m_transfer.flags = 0;
m_transaction.callback = app_twi_callback;
m_transaction.number_of_transfers = 1;
m_transaction.p_required_twi_cfg = 0;
m_transaction.p_transfers = &m_transfer;
m_transaction.p_user_data = (void*) PAL_STATUS_SUCCESS;
if (nrf_twi_mngr_schedule(&m_app_twi, &m_transaction) != NRF_SUCCESS)
{
app_twi_callback(NRF_ERROR_BUSY, 0);
}
return PAL_STATUS_SUCCESS;
}
/**
* Platform abstraction layer API to set the bitrate/speed(KHz) of I2C master.
*
*
*API Details:
* - Sets the bitrate of I2C master if the I2C bus is free, else it returns busy status #PAL_STATUS_I2C_BUSY
* - The bus is released after the setting the bitrate.
* - This API must take care of setting the bitrate to I2C master's maximum supported value.
* - Eg. In XMC4500, the maximum supported bitrate is 400 KHz. If the supplied bitrate is greater than 400KHz, the API will
* set the I2C master's bitrate to 400KHz.
* - Use the #PAL_I2C_MASTER_MAX_BITRATE macro to specify the maximum supported bitrate value for the target platform.
* - If upper_layer_event_handler is initialized, the upper layer handler is invoked with the respective event
* status listed below.
* - #PAL_I2C_EVENT_BUSY when I2C bus in busy state
* - #PAL_I2C_EVENT_ERROR when API fails to set the bit rate
* - #PAL_I2C_EVENT_SUCCESS when operation is successful
*
*
*User Input:
* - The input #pal_i2c_t p_i2c_context must not be NULL.
*
* \param[in] p_i2c_context Pointer to the pal i2c context
* \param[in] bitrate Bitrate to be used by i2c master in KHz
*
* \retval #PAL_STATUS_SUCCESS Returns when the setting of bitrate is successfully completed
* \retval #PAL_STATUS_FAILURE Returns when the setting of bitrate fails.
* \retval #PAL_STATUS_I2C_BUSY Returns when the I2C bus is busy.
*/
pal_status_t pal_i2c_set_bitrate(const pal_i2c_t* p_i2c_context , uint16_t bitrate)
{
// Bitrate is fixed to the maximum frequency on this platform (400K)
return PAL_STATUS_SUCCESS;
}
/**
* @}
*/