change pin mux in TF-A build for i2c-bus i2c4

[RGlie.1]

We would like to build the TF-A image with a different muxer setting

for i2c4. The usual setting is:

i2c4_pins_a: i2c4-0 {

   pins {

      pinmux = <STM32_PINMUX('Z', 4, AF6)>, /* I2C4_SCL */

      <STM32_PINMUX('Z', 5, AF6)>; /* I2C4_SDA */

      bias-disable;

      drive-open-drain;

      slew-rate = <0>;

   };

};

our setup:

i2c4_pins_a: i2c4-0 {

   pins {

      pinmux = <STM32_PINMUX('H', 11, AF6)>, /* I2C4_SCL */

      <STM32_PINMUX('H', 12, AF6)>; /* I2C4_SDA */

      bias-disable;

      drive-open-drain;

      slew-rate = <0>;

   };

};

If we use the changed pin muxing we get no signal output on those pins.

My question, is it possible to change the pin muxing

or is the muxing for I2C4 fixed for the TF-A build ?

[Olivier GALLIEN]

​Hi @RGlie.1​ 

I suspect you are facing known GPIO clock issue in V2.0.

Cf https://community.st.com/s/question/0D53W00000JQ4z4SAD/stm32mp1-ecosystem-known-bugs-and-common-pitfalls

Olivier

[RGlie.1 · Accepted solution]

Hello Olivier,

after updating the TF-A firmware to version v2.2-r1.4 the problem

is solved.

I think the reason was the issue:

"GPIO clock not enabled in BL32"

thank you,

Ralf