IO expander hardware components

1 Article purpose[edit]

The purpose of this article is to:

  • list the I/O expander hardware components that might be integrated in the different STM32MPU boards
  • link these components to the corresponding software framework(s)
  • point to the datasheet(s) of these components
  • explain, when necessary, how to configure these components

2 Software frameworks[edit]

Domain Peripheral Software components Comment
OP-TEE Linux STM32Cube
Core/I/Os ST MFX (Multi-Function eXpander) Linux IOs pins overview I/O expander

3 ST MFX (Multi-Function eXpander)[edit]

The ST MFX is an STM32L152 slave controller whose firmware embeds an I/O expander feature with 16 GPIOs + 8 GPIOs extra if other features (resistive touchscreen controller and IDD measurement) are not enabled.

For details, refer to UM2535, chapter MFX IO expander.

3.1 Linux driver[edit]

Bindings: Documentation/devicetree/bindings/mfd/st,stmfx.yaml