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Merge pull request #340 from philljj/iocb_microchipharmony_i2c
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Iocb microchipharmony i2c
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@dgarske
dgarske authored Jan 6, 2025
2 parents 6e1205b + a2fede3 commit 703b728
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Showing 3 changed files with 229 additions and 3 deletions.
3 changes: 3 additions & 0 deletions hal/tpm_io.c
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Original file line number Diff line number Diff line change
Expand Up @@ -148,6 +148,9 @@ int TPM2_IoCb(TPM2_CTX* ctx, INT32 isRead, UINT32 addr,
ret = TPM2_IoCb_Infineon_I2C(ctx, isRead, addr, buf, size, userCtx);
#elif defined(WOLFSSL_ESPIDF)
ret = TPM2_IoCb_Espressif_I2C(ctx, isRead, addr, buf, size, userCtx);
#elif defined(WOLFTPM_MICROCHIP_HARMONY)
/* Use Microchip Harmony I2C */
ret = TPM2_IoCb_MicrochipHarmony_I2C(ctx, isRead, addr, buf, size, userCtx);
#else
/* TODO: Add your platform here for HW I2C interface */
printf("Add your platform here for HW I2C interface\n");
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3 changes: 3 additions & 0 deletions hal/tpm_io.h
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Original file line number Diff line number Diff line change
Expand Up @@ -88,6 +88,9 @@ WOLFTPM_LOCAL int TPM2_IoCb_Infineon_I2C(TPM2_CTX* ctx, int isRead, word32 addr,
#elif defined(WOLFSSL_ESPIDF)
WOLFTPM_LOCAL int TPM2_IoCb_Espressif_I2C(TPM2_CTX* ctx, int isRead, word32 addr,
byte* buf, word16 size, void* userCtx);
#elif defined(WOLFTPM_MICROCHIP_HARMONY)
WOLFTPM_LOCAL int TPM2_IoCb_MicrochipHarmony_I2C(TPM2_CTX* ctx, int isRead, word32 addr,
byte* buf, word16 size, void* userCtx);
#endif /* __linux__ */

#else /* SPI */
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226 changes: 223 additions & 3 deletions hal/tpm_io_microchip.c
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Original file line number Diff line number Diff line change
Expand Up @@ -49,13 +49,232 @@

#if defined(WOLFTPM_MICROCHIP_HARMONY)

#include "configuration.h"
#include "definitions.h"

#ifdef WOLFTPM_I2C /* Microchip Harmony Hal I2C */
/* We are using the I2C bit-bang library. */
#include <i2cbb/i2c_bb.h>
/* Use sys_time to implement delay. */
#include "system/time/sys_time.h"

#ifndef TPM_I2C_TRIES
#define TPM_I2C_TRIES 10
#endif
#ifndef TPM2_I2C_ADDR
#define TPM2_I2C_ADDR 0x2e
#endif

static uintptr_t dummy_context;

static void dummy_callback(uintptr_t context)
{
(void) context;
return;
}

/* Wait for time_ms using Microchip Harmony SYS_TIME API. */
static void microchip_wait(uint32_t time_ms)
{
/* Microchip Harmony example from documentation.
* SYS_TIME_DelayMS will internally create the timer,
* and SYS_TIME_DelayIsComplete will delete it when
* the delay has completed. */
SYS_TIME_HANDLE timer = SYS_TIME_HANDLE_INVALID;

if (SYS_TIME_DelayMS(time_ms, &timer) != SYS_TIME_SUCCESS) {
printf("error: microchip_wait: SYS_TIME_DelayMS failed\n");
}
else if(SYS_TIME_DelayIsComplete(timer) != true) {
/* Loop until delay is complete. */
while (SYS_TIME_DelayIsComplete(timer) == false);
}

return;
}

/* Microchip Harmony I2C */
static int i2c_read(void* userCtx, word32 reg, byte* data, int len)
{
int ret = TPM_RC_FAILURE;
I2CBB_ERROR status = I2CBB_ERROR_NONE;
bool queued = false;
int timeout = TPM_I2C_TRIES;
int busy_retry = TPM_I2C_TRIES;
byte buf[1];

if (I2C_BB_IsBusy()) {
printf("error: i2c_read: already busy\n");
return -1;
}

/* TIS layer should never provide a buffer larger than this,
but double check for good coding practice */
if (len > MAX_SPI_FRAMESIZE) {
printf("error: i2c_read: len too large: %d\n", len);
return BAD_FUNC_ARG;
}

buf[0] = (reg & 0xFF); /* convert to simple 8-bit address for I2C */

do {
/* Queue the write with I2C_BB. */
queued = I2C_BB_Write(TPM2_I2C_ADDR, buf, sizeof(buf));

if (!queued) {
printf("error: i2c_read: I2C_BB_Write failed\n");
return -1;
}

busy_retry = TPM_I2C_TRIES;

while (I2C_BB_IsBusy() && --busy_retry > 0) {
microchip_wait(250);
}

if (I2C_BB_IsBusy()) {
printf("error: i2c_read: busy wait timed out\n");
return -1;
}

status = I2C_BB_ErrorGet();
if (status == I2CBB_ERROR_NAK) {
microchip_wait(250);
}
} while (status == I2CBB_ERROR_NAK && --timeout > 0);

if (status != I2CBB_ERROR_NONE) {
if (status == I2CBB_ERROR_NAK) {
printf("error: i2c_read: I2C_BB_Write failed with NAK: %d\n",
status);
}
else {
printf("error: i2c_read: I2C_BB_Write failed: %d\n", status);
}

return -1;
}

timeout = TPM_I2C_TRIES;

do {
/* Queue the read with I2C_BB. */
queued = I2C_BB_Read(TPM2_I2C_ADDR, data, len);

if (!queued) {
printf("error: i2c_read: I2C_BB_Read failed\n");
return -1;
}

busy_retry = TPM_I2C_TRIES;

while (I2C_BB_IsBusy() && --busy_retry > 0) {
microchip_wait(250);
}

status = I2C_BB_ErrorGet();
if (status == I2CBB_ERROR_NAK) {
microchip_wait(250);
}
} while (status == I2CBB_ERROR_NAK && --timeout > 0);

if (status == I2CBB_ERROR_NONE) {
ret = TPM_RC_SUCCESS;
}
else {
printf("error: I2C Read failure %d (tries %d)\n",
status, TPM_I2C_TRIES - timeout);
}

return ret;
}

static int i2c_write(void* userCtx, word32 reg, byte* data, int len)
{
int ret = TPM_RC_FAILURE;
I2CBB_ERROR status = I2CBB_ERROR_NONE;
bool queued = false;
int timeout = TPM_I2C_TRIES;
int busy_retry = TPM_I2C_TRIES;
byte buf[MAX_SPI_FRAMESIZE+1];

/* TIS layer should never provide a buffer larger than this,
but double check for good coding practice */
if (len > MAX_SPI_FRAMESIZE) {
printf("error: i2c_write: len too large: %d\n", len);
return BAD_FUNC_ARG;
}

if (I2C_BB_IsBusy()) {
printf("error: i2c_write: already busy\n");
return -1;
}

/* Build packet with TPM register and data */
buf[0] = (reg & 0xFF); /* convert to simple 8-bit address for I2C */
XMEMCPY(buf + 1, data, len);

do {
/* Queue the write with I2C_BB. */
queued = I2C_BB_Write(TPM2_I2C_ADDR, buf, len + 1);

if (!queued) {
printf("error: i2c_write: I2C_BB_Write failed: %d\n", status);
return -1;
}

while (I2C_BB_IsBusy() && --busy_retry > 0) {
microchip_wait(250);
}

status = I2C_BB_ErrorGet();

if (status == I2CBB_ERROR_NAK) {
microchip_wait(250);
}
} while (status == I2CBB_ERROR_NAK && --timeout > 0);

if (status == I2CBB_ERROR_NONE) {
ret = TPM_RC_SUCCESS;
}
else {
printf("I2C Write failure %d\n", status);
}
return ret;
}

int TPM2_IoCb_MicrochipHarmony_I2C(TPM2_CTX* ctx, int isRead, word32 addr,
byte* buf, word16 size, void* userCtx)
{
int ret = TPM_RC_FAILURE;

/* Set callback to null to do time based polling of
* I2C_BB_IsBusy instead.
*
* Note: Apparently a callback is actually required,
* even if not used.
* */
I2C_BB_Initialize();
I2C_BB_CallbackRegister(dummy_callback, dummy_context);

if (isRead) {
ret = i2c_read(userCtx, addr, buf, size);
}
else {
ret = i2c_write(userCtx, addr, buf, size);
}

(void)userCtx;
(void)ctx;

return ret;
}
#else /* Microchip Harmony Hal SPI */

#ifdef WOLFTPM_CHECK_WAIT_STATE
#error This driver does not support check wait state yet
#endif

#include "configuration.h"
#include "definitions.h"

/* TPM Chip Select Pin (default PC5) */
#ifndef TPM_SPI_PIN
#define SYS_PORT_PIN_PC5
Expand Down Expand Up @@ -98,6 +317,7 @@ int TPM2_IoCb_Microchip_SPI(TPM2_CTX* ctx, const byte* txBuf, byte* rxBuf,
return ret;
}

#endif /* WOLFTPM_I2C */
#endif /* WOLFTPM_MICROCHIP_HARMONY */
#endif /* !(WOLFTPM_LINUX_DEV || WOLFTPM_SWTPM || WOLFTPM_WINAPI) */
#endif /* WOLFTPM_INCLUDE_IO_FILE */
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