STM32: change the pinctrl state for i2c bus dinamically

marcorivolta-LSI commented 5 months ago

I'm working on a custom board with a STM32WB controller and an array of five I2C sensors.

Due to some constraints, the five sensors are on the same i2c bus. Since the sensor allows up to 4 configurable addresses, there are two SCL lines. The first one goes to sensor 1 to 4, the second one goes to sensor 5.

I'm trying to determine if it's possible to dynamically change the SCL pin used by the I2C bus with the STM32 I2C driver, but it doesn't seem feasible.

The i2c bus is activated by "i2c_stm32_activate" function in "i2c_ll_stm32.c":

/* Move pins to active/default state */
ret = pinctrl_apply_state(cfg->pcfg, PINCTRL_STATE_DEFAULT);
if (ret < 0) {
    LOG_ERR("I2C pinctrl setup failed (%d)", ret);
    return ret;
}

It would seem that there is no possibility to change the pinctrl state at runtime.

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erwango commented 5 months ago

See dynamic pinctrl status in doc: https://docs.zephyrproject.org/latest/hardware/pinctrl/index.html#dynamic-pin-control

This feature is supported to some extent, but not in the scope of your expectations. I'm closing the issue for the time being.

zephyrproject-rtos / zephyr

STM32: change the pinctrl state for i2c bus dinamically #71427