This function was a duplication of the existing gpio_init_mux,
where the exiting function is the more general one, as the mux
inititalization is not only valid for the sercom module...
The following features were tested (briefly):
* UART (the first)
* I2C using a BMP180 on a SODAQ TPH board
* SPI0, connected to the on-board serial data flash (only DevID was read
using the periph_spi test program)
* xtimer is working (it's the same code as in samr21)
boards/sodaq-autonomo: Disable the "big" unittests because it does not fit
This adds support for all samd21 variants. Notice that the previous samd21
was moved to cpu/samr21
To use this cpu variant you must set at least the following in your boards
Makefile.include:
export CPU = samd21
export CPU_MODEL = samd21j18a # Not sure if this is used
CFLAGS += -D__SAMD21J18A__ # or whatever variant you have
The samd21 include files were copied from ASF 3.30
This define conflicts with LITTLE_ENDIAN defined in
include/machine/endian.h which is part of gcc-arm-none-eabi.
Also, the define does not seem to be used by the ASF included files.
The former i2c_init_master was too complicated. It was trying to set IN/OUT
mode of the pins, but all that is needed is to set the proper MUX.
Also the configuration for the boards was incomplete (no MUX, no pad
setting).
It was tested on a SODAQ Autonomo, but not on a samr21-xpro
