`tmf8829_probe` SPI default path fails: `tmf8829PowerUp` runs before `BL_CMD_I2C_OFF` latches the interface

[rowandempster]

Reproduction:

static int setup_chip(tmf8829_chip *chip)
{
// Set Bus type to SPI
tmf8829_set_busType(chip, 1);
enablePinHigh(chip);
tmf8829_probe(chip);
}

Yields tmf8829_probe failed.

However, moving the

    /* Switch off unused communication interface */
    if (chip->bustype == BUS_SPI)
        error = tmf8829BootloaderCmdI2cOff(driver);
    else
        error = tmf8829BootloaderCmdSpiOff(driver);

block before tmf8829PowerUp(driver); in tmf8829_probe and running the same reproduction code yields TMF8829 probe OK.

[ptr814]

Hi @rowandempster,
we can't reproduce your issue on our side - can you tell which command in tmf8829_probe fails? Is the delayInMicroseconds mapped to your actual delay function for your platform?

If you keep tmf8829BootloaderCmdI2cOff before tmf8829PowerUp(driver), the TMF8829 might ignore this command and keep I2C and SPI bus simultaneously open. This is generally not allowed according to our datasheet.

Thank you
Regards Peter