[En-Nut-Discussion] RFC: New driver interface for TWI, I2C and others

[Ulrich Prinz]

Hihi...

My fault... or at least a bit imprecise.

stm32_twi.h says

#ifndef DEF_TWIBUS
#ifdef I2CBUS1_AS_DEFAULT
#define DEF_TWIBUS Stm32TwiBus_1
#else
#define DEF_TWIBUS Stm32TwiBus_2
#endif
#endif

So if you like to have the other one as default use this:
#define DEF_TWIBUS Stm32TwiBus_2
before stm32_twi.h is included.

I'll think I change this in nutconf to be more precise...

Ah, ok, that is the reason for the inconvenience:
Nutconf cannot have more subdirectories of features like
options = {
  options = {
  ...
  }
}

So I cannot give a selection like
I2C Bus
	Select Default I2C Bus
	I2C Bus 1
	  options
	I2C Bus 2
	  options

So I added it as first selectable option into the different i2c of the
STM32.
I2C Bus 1
  select this as defualt
  option 2
  option 3
I2C Bus 2
  select this as defualt
  option 2
  option 3

In the USART it is done differently as there is a debug uart as a
separate device what simply lets you choose one of the x USARTs the STM
has.

If you like to use the API directly, use
NutRegisterTwiBus( &Stm32TwiBus_2, 0);
And have a look for the other NutTwixxx functions in stm32_twi.c.
Calling is identical to Twxxx functions but you must add the Bus as
first parameter. So
TwMasterRegRead( chip, addr, addrl, buf, len, tout);
is now
NutTwMasterRegRead( bus, chip, addr, addrl, buf, len, tout);

Thats all.

Ulrich