Extend GPIO mode

[fpistm]

Current mode available using pinMode() are:

• INPUT
• INPUT_PULLUP
• INPUT_PULLDOWN
• OUTPUT

Some other mode could be added as done in Arduino_STM32
At least:

• INPUT_ANALOG
• INPUT_FLOATING same as INPUT
• OUTPUT_OPEN_DRAIN

Maybe AF mode.

[Adminius]

Hi @fpistm ,
it sounds interesting, but this will make STM32 core incompatible to Arduino (if anybody will port STM32 sketch to Arudino)...

INPUT_ANALOG is the "same" as analogRead
INPUT_FLOATING is the same as INPUT
OUTPUT_OPEN_DRAIN ist the same as OUTPU LOW + INPUT...

IMHO: only INPUT_PULLDOWN makes sense.

[fpistm]

I think no, it will not make core incompatible this is just an extension. Default Arduino value are kept.
If user use it yes his sketch will be incompatible but if he use it this is probably to take benefits of STM32 features. Up to him to tag it as STM32 compatible only.

[davidanger]

What is different between INPUT, INPUT_ANALOGand INPUT_FLOATING?
I think maybe like that:
INPUT (MODER:00 PUPDR:00) as same as INPUT_FLOATING
INPUT_ANALOG (MODER:11 PUPDR:00)
Right?

[davidanger]

I think add one more OUTPUT_PULLUPorOUTPUT_OPEN_DRAIN_PULLUP (MODER:01 OTYPER:1 PUPDR:01) OpenDrain + Pullup maybe have some useful in some cases.
Can make I2C or something like that.

[fpistm]

Right.
Why not add some new OUTPUT_* value.
Currently for some specific feature the config is get from the PeripheralPins.c
ex for ADC pin:
{PC_2, ADC1, STM_PIN_DATA_EXT(STM_MODE_ANALOG, GPIO_NOPULL, 0, 3, 0)}, // ADC1_IN3

where STM_PIN_DATA is used to get pin configuration coded on 32 bits:
STM PIN data as used in pin_function is coded on 32 bits as below:

    [2:0]  Function (like in MODER reg) : Input / Output / Alt / Analog
       [3]  Output Push-Pull / Open Drain (as in OTYPER reg)
    [5:4]  as in PUPDR reg: No Pull, Pull-up, Pull-Donc
    [7:6]  Reserved for speed config (as in OSPEEDR), but not used yet
  [14:8]  Alternate Num (as in AFRL/AFRG reg)
[19:15]  Channel (Analog/Timer specific)
     [20]  Inverted (Analog/Timer specific)
     [21]  Analog ADC control - Only valid for specific families
[32:22]  Reserved

See https://github.com/stm32duino/Arduino_Core_STM32/blob/master/cores/arduino/stm32/PinNamesTypes.h#L36