[FAQ] How to run OTP Keywriter on SK-AM64B

Hello Lalie,
It looks like a different IO-expander for turnning ON/OFF VPP is used on SK vs EVM.
Some additional work is needed to make TCA9538PWR work first in order to run OTP KW on SK board.
- SK:
IO EXPANDER TCA9538PWR => VPP_LDO_EN
- EVM:
IO EXPANDER TCA6424ARGJR => VPP_LDO_EN
Best,
-Hong

Hello Hong and thanks for your reply,

Has this work already been done by somebody?

If not, I suppose that updating the mcu+sdk/board source code in order to add TCA9538 support will solve my problem, is it right?

Thanks!

Lalie

Update: I finally found how to make KW work for SK-AM64B; is it going to be in TI's next Keywriter release or can I post my solution in this forum ?

Update 2: To support the SK-AM64B board in OTP Keywriter, you'll need to:
- add TCA9538 IOExpander code in your {MCU+SDK_INSTALL_PATH}/source/board directory.
- add SK-AM64B board code in your {MCU+SDK_INSTALL_PATH}/source/security/tifs/sbl_keywriter/am64x-skb/rfss0-0_nortos directory.
- a script compile_all.sh is also provided there in order to compile newly added TCA9538 support and the keywriter tool for the SK-AM64B.

Then, all you need to do is to follow OTP Keywriter's User Guide for AM64x EVM and change the paths with SK-B's ones.

#!/bin/bash

# This script's aim is to compile board sources + keywriter for SK-AM64B
# Needs to be placed in ${SDK_INSTALL_PATH}/source/security/tifs/sbl_keywriter/am64x-skb/r5fss0-0_nortos/compile_all.sh

# Compiling board libs
cd ../../../../../board
make --makefile=makefile.am64x.r5f.ti-arm-clang all -sj PROFILE=debug

# Compiling SK-AM64B OTP Keywriter
cd ../security/tifs/sbl_keywriter/am64x-skb/r5fss0-0_nortos/ti-arm-clang
make clean -sj PROFILE=debug && make -sj PROFILE=debug

# Regenerating tiboot3.bin (follow OTP Keywriter's User Guide)
# cd ../../../scripts/cert_gen
# ./gen_cert_auto.sh

Enjoy !

// {MCU+SDK_INSTALL_PATH}/source/board/ioexp/ioexp_tca9538.c

/* ========================================================================== */
/*                             Include Files                                  */
/* ========================================================================== */

#include <board/ioexp/ioexp_tca9538.h>

/* ========================================================================== */
/*                           Macros & Typedefs                                */
/* ========================================================================== */

#define TCA9538_REG_INPUT_PORT        (0x00U)
#define TCA9538_REG_OUTPUT_PORT       (0x01U)
#define TCA9538_REG_POL_INV_PORT      (0x02U)
#define TCA9538_REG_CONFIG_PORT       (0x03U)

/* ========================================================================== */
/*                         Structure Declarations                             */
/* ========================================================================== */

/* None */

/* ========================================================================== */
/*                          Function Declarations                             */
/* ========================================================================== */

/* None */

/* ========================================================================== */
/*                            Global Variables                                */
/* ========================================================================== */

/* None */

/* ========================================================================== */
/*                          Function Definitions                              */
/* ========================================================================== */

int32_t TCA9538_open(TCA9538_Config *config, const TCA9538_Params *params)
{
    int32_t         status = SystemP_SUCCESS;

    if((NULL == config) || (NULL == params))
    {
        status = SystemP_FAILURE;
    }
    else
    {
        config->params.i2cInstance = params->i2cInstance;
        config->params.i2cAddress  = params->i2cAddress;
        config->lock               = NULL;
        config->i2cHandle          = I2C_getHandle(config->params.i2cInstance);
        if(NULL == config->i2cHandle)
        {
            status = SystemP_FAILURE;
        }
    }

    if(status == SystemP_SUCCESS)
    {
        SemaphoreP_constructMutex(&config->lockObj);
        config->lock = &config->lockObj;
        TCA9538_getAttrs(config, &config->attrs);
    }

    return (status);
}

void TCA9538_close(TCA9538_Config *config)
{

    if(NULL == config)
    {
    }
    else
    {
        /* I2C Driver will be closed outside flash */
        config->i2cHandle = NULL;
        if(NULL != config->lock)
        {
            SemaphoreP_destruct(&config->lockObj);
            config->lock = NULL;
        }
    }

    return;
}

int32_t TCA9538_config(TCA9538_Config *config, uint32_t ioIndex, uint32_t mode)
{
    int32_t         status = SystemP_SUCCESS;
    I2C_Transaction i2cTransaction;
    uint32_t        portPin, i2cAddress;
    uint8_t         buffer[2U] = {0};

    if(NULL == config)
    {
        status = SystemP_FAILURE;
    }
    else
    {
        /* Validate input IO number */
        if(ioIndex >= config->attrs.numIo)
        {
            status = SystemP_FAILURE;
        }
    }

    if(status == SystemP_SUCCESS)
    {
        /* Each port contains 8 IOs */
        portPin     = ioIndex;
        i2cAddress  = config->params.i2cAddress;

        SemaphoreP_pend(&config->lockObj, SystemP_WAIT_FOREVER);

        /* Set config register address - needed for next read */
        I2C_Transaction_init(&i2cTransaction);
        buffer[0] = TCA9538_REG_CONFIG_PORT;
        i2cTransaction.writeBuf     = buffer;
        i2cTransaction.writeCount   = 1U;
        i2cTransaction.slaveAddress = i2cAddress;
        status += I2C_transfer(config->i2cHandle, &i2cTransaction);

        /* Read config register value */
        I2C_Transaction_init(&i2cTransaction);
        i2cTransaction.readBuf      = buffer;
        i2cTransaction.readCount    = 1;
        i2cTransaction.slaveAddress = i2cAddress;
        status += I2C_transfer(config->i2cHandle, &i2cTransaction);

        /* Set output or input mode to particular IO pin - read/modify/write */
        I2C_Transaction_init(&i2cTransaction);
        if(TCA9538_MODE_INPUT == mode)
        {
            buffer[1] = buffer[0] | (0x01 << portPin);
        }
        else
        {
            buffer[1] = buffer[0] & ~(0x01 << portPin);
        }
        buffer[0] = TCA9538_REG_CONFIG_PORT;
        i2cTransaction.writeBuf     = buffer;
        i2cTransaction.writeCount   = 2;
        i2cTransaction.slaveAddress = i2cAddress;
        status += I2C_transfer(config->i2cHandle, &i2cTransaction);

        SemaphoreP_post(&config->lockObj);
    }
    return (status);
}

int32_t TCA9538_setOutput(TCA9538_Config *config, uint32_t ioIndex, uint32_t state)
{
    int32_t         status = SystemP_SUCCESS;
    I2C_Transaction i2cTransaction;
    uint32_t        port, portPin, i2cAddress;
    uint8_t         buffer[2U] = {0};

    if(NULL == config)
    {
        status = SystemP_FAILURE;
    }
    else
    {
        /* Validate input IO number */
        if(ioIndex >= config->attrs.numIo)
        {
            status = SystemP_FAILURE;
        }
    }

    if(status == SystemP_SUCCESS)
    {
        /* Each port contains 8 IOs */
        port        = ioIndex >> 3U;        /* /8 gives port */
        portPin     = ioIndex & 0x07U;      /* %8 gives pin within port */
        i2cAddress  = config->params.i2cAddress;

        SemaphoreP_pend(&config->lockObj, SystemP_WAIT_FOREVER);

        /* Set output prt register address - needed for next read */
        I2C_Transaction_init(&i2cTransaction);
        buffer[0] = TCA9538_REG_OUTPUT_PORT + port;
        i2cTransaction.writeBuf     = buffer;
        i2cTransaction.writeCount   = 1U;
        i2cTransaction.slaveAddress = i2cAddress;
        status += I2C_transfer(config->i2cHandle, &i2cTransaction);

        /* Read config register value */
        I2C_Transaction_init(&i2cTransaction);
        i2cTransaction.readBuf      = buffer;
        i2cTransaction.readCount    = 1;
        i2cTransaction.slaveAddress = i2cAddress;
        status += I2C_transfer(config->i2cHandle, &i2cTransaction);

        /* Set output or input mode to particular IO pin - read/modify/write */
        I2C_Transaction_init(&i2cTransaction);
        if(TCA9538_OUT_STATE_HIGH == state)
        {
            buffer[1] = buffer[0] | (0x01 << portPin);
        }
        else
        {
            buffer[1] = buffer[0] & ~(0x01 << portPin);
        }
        buffer[0] = TCA9538_REG_OUTPUT_PORT;
        i2cTransaction.writeBuf     = buffer;
        i2cTransaction.writeCount   = 2;
        i2cTransaction.slaveAddress = i2cAddress;
        status += I2C_transfer(config->i2cHandle, &i2cTransaction);

        SemaphoreP_post(&config->lockObj);
    }

    return (status);
}

void TCA9538_getAttrs(TCA9538_Config *config, TCA9538_Attrs *attrs)
{
    if(NULL != attrs)
    {
        attrs->numIo = 8U;
    }

    return;
}

void TCA9538_Params_init(TCA9538_Params *params)
{
    if(NULL != params)
    {
        params->i2cInstance = 0U;
        params->i2cAddress  = 0x70;
    }

    return;
}

// {MCU+SDK_INSTALL_PATH}/source/board/ioexp/ioexp_tca9538.h

/**
 *  \defgroup BOARD_IO_EXPANDER_TCA9538_MODULE APIs for TCA9538 IO Expander driver
 *  \ingroup BOARD_MODULE
 *
 *  This module contains APIs to program and use I2C based TCA9538 IO Expander
 *  module on the board.
 *
 *  @{
 */

#ifndef IO_EXP_TCA9538_H_
#define IO_EXP_TCA9538_H_

/* ========================================================================== */
/*                             Include Files                                  */
/* ========================================================================== */

#include <stdint.h>
#include <kernel/dpl/SystemP.h>
#include <kernel/dpl/SemaphoreP.h>
#include <drivers/i2c.h>

#ifdef __cplusplus
extern "C" {
#endif

/* ========================================================================== */
/*                           Macros & Typedefs                                */
/* ========================================================================== */

/**
 *  \anchor TCA9538_Mode
 *  \name IO pin mode - Input or Output
 *  @{
 */
/** \brief Configure IO pin as input */
#define TCA9538_MODE_INPUT              (0U)
/** \brief Configure IO pin as output */
#define TCA9538_MODE_OUTPUT             (1U)
/** @} */

/**
 *  \anchor TCA9538_OutState
 *  \name IO pin output state - HIGH or LOW
 *  @{
 */
/** \brief Configure IO pin output as LOW */
#define TCA9538_OUT_STATE_LOW           (0U)
/** \brief Configure IO pin output as HIGH */
#define TCA9538_OUT_STATE_HIGH          (1U)
/** @} */

/* ========================================================================== */
/*                         Structure Declarations                             */
/* ========================================================================== */

/**
 *  \brief Parameters passed during TCA9538_open()
 */
typedef struct TCA9538_Params_s
{
    uint32_t        i2cInstance;
    /**< Underlying peripheral driver instance that is used by the
     *   IO Expander driver incase of I2C controlled IO Expander */
    uint32_t        i2cAddress;
    /**< I2C address for IO expander */
} TCA9538_Params;

/**
 *  \brief IO Expander device attributes.
 */
typedef struct TCA9538_Attrs_s
{
    uint32_t        numIo;
    /**< Number of IO supported by device */
} TCA9538_Attrs;

/**
 *  \brief IO Expander driver configuration. This is the driver object used to
 *  store state variables
 */
typedef struct TCA9538_Config_s
{
    TCA9538_Params      params;
    /**< Parameters */
    TCA9538_Attrs       attrs;
    /**< Attributes */
    I2C_Handle          i2cHandle;
    /**< I2C driver handle */
    void               *lock;
    /**< Mutex to protect IO expander access. */
    SemaphoreP_Object   lockObj;
    /**< Mutex object. */
} TCA9538_Config;

/* ========================================================================== */
/*                          Function Declarations                             */
/* ========================================================================== */

/**
 *  \brief Open TCA9538 driver
 *
 *  Make sure the I2C driver is opened before calling this API.
 *
 *  \param config       [IN] Driver object. Caller need to allocate memory for this.
 *  \param params       [IN] Open parameters
 *
 * \return SystemP_SUCCESS on success, else failure
 */
int32_t TCA9538_open(TCA9538_Config *config, const TCA9538_Params *params);

/**
 *  \brief Close TCA9538 driver
 *
 *  \param config    [IN] TCA9538 driver config from \ref TCA9538_open
 */
void TCA9538_close(TCA9538_Config *config);

/**
 * \brief API to set a IO pin of TCA9538 as input or output
 *
 * \param config    [IN] TCA9538 driver config from \ref TCA9538_open
 * \param ioIndex   [IN] Index to the TCA9538 IO which needs to be set/reset.
 * \param mode      [IN] Refer \ref TCA9538_Mode
 *
 * \return SystemP_SUCCESS on success, else failure
 */
int32_t TCA9538_config(TCA9538_Config *config, uint32_t ioIndex, uint32_t mode);

/**
 * \brief API to set a IO pin of TCA9538 to either HIGH or LOW
 *
 * \param config    [IN] TCA9538 driver config from \ref TCA9538_open
 * \param ioIndex   [IN] Index to the TCA9538 IO which needs to be set/reset.
 * \param state     [IN] Refer \ref TCA9538_OutState
 *
 * \return SystemP_SUCCESS on success, else failure
 */
int32_t TCA9538_setOutput(TCA9538_Config *config, uint32_t ioIndex, uint32_t state);

/**
 * \brief Returns TCA9538 attributes
 *
 * \param config    [IN] TCA9538 driver config from \ref TCA9538_open
 * \param attrs     [IN/OUT] Structure where the attribute is returned
 *
 */
void TCA9538_getAttrs(TCA9538_Config *config, TCA9538_Attrs *attrs);

/**
 *  \brief Set default parameters in the \ref TCA9538_Params structure
 *
 *  Call this API to set defaults and then override the fields as needed
 *  before calling  \ref TCA9538_open.
 *
 *  \param params   [OUT] Initialized parameters
 */
void TCA9538_Params_init(TCA9538_Params *params);

/* ========================================================================== */
/*                       Static Function Definitions                          */
/* ========================================================================== */

/* None */

/* ========================================================================== */
/*                  Internal/Private Structure Declarations                   */
/* ========================================================================== */

/* None */

#ifdef __cplusplus
}
#endif

#endif /* #ifndef TCA9538_H_ */

/** @} */

// {MCU+SDK_INSTALL_PATH}/source/security/tifs/sbl_keywriter/am64x-skb/r5fss0-0_nortos/board.c

#include <board/ioexp/ioexp_tca9538.h>
#include <kernel/dpl/CacheP.h>

/* TP89 VPP CORE on SK-AM64B */
#define EFUSE_VPP_PIN (4U) // IOExpander-P04

/* *
 * This function sets the VPP voltage for the SoC. 
 * VPP pin is controlled via IO Expander-P4 on SK-AM64B.
 * */
void keywriter_setVpp()
{
	int32_t status;

	TCA9538_Params TCA9538_IOexp_params = 
	{
		.i2cInstance = 0,  
		.i2cAddress = 0x70 
	}; 

	TCA9538_Config TCA9538_IOexp_config ; 

    status = TCA9538_open(&TCA9538_IOexp_config, &TCA9538_IOexp_params);

	/* set VPP core */
    if (status == SystemP_SUCCESS)
	{	
		status = TCA9538_config(&TCA9538_IOexp_config, EFUSE_VPP_PIN, TCA9538_MODE_OUTPUT);
	}

    if (status == SystemP_SUCCESS)
	{	
    	status = TCA9538_setOutput(&TCA9538_IOexp_config, EFUSE_VPP_PIN, TCA9538_OUT_STATE_HIGH);
	}

    TCA9538_close(&TCA9538_IOexp_config);
	
	DebugP_assertNoLog(status==SystemP_SUCCESS);
}