Because the CC2538 has a multi-byte SPI RX FIFO, flushing the buffer
requires more than just a single read. This adds a loop that empties the
entire RX buffer on a FLUSH().
Different SPI chips needs different SPI settings. This commit adds a
function that allows chip drivers to configure the SPI peripheral before
using it.
The frame pin the driver was using as a chip select does not work as
most devices expect it to. It toggles after every byte, and most chips
interpret that as end of message. To make drivers more reliable, each
chip driver should setup a GPIO and assert it as needed.
Homogenize port and pin definitions naming:
- PERIPHERAL_FUNCTION_PORT for the port ID,
- PERIPHERAL_FUNCTION_PIN for the pin ID,
- PERIPHERAL_FUNCTION_PORT_BASE for the port base,
- PERIPHERAL_FUNCTION_PIN_MASK for the pin mask.
Define only PERIPHERAL_FUNCTION_PORT and PERIPHERAL_FUNCTION_PIN in board.h, and
deduce PERIPHERAL_FUNCTION_PORT_BASE and PERIPHERAL_FUNCTION_PIN_MASK in the
driver from the former definitions.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Use the GPIO accessor macros instead of copying raw register access code all
over the place. This is cleaner and less error prone.
This fixes the setting of the USB pull-up resistor that worked only by chance on
the CC2538DK because it is controlled by the pin 0 of the used GPIO port.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
This uses the core/dev/spi.h header and implements the spi_init()
function and the various macros for SPI operation. ssi.h contains all of
the register locations and information.
This implementation is not very versatile, mostly because I don't how to
make it flexible in the contiki system. It supports pin muxing for the
four spi pins, but other than that picks sensible defaults.
The SPI macros (like SPI_READ()) are defined in
cpu/cc2538/spi-arch.h. In order to use the SPI driver, add the following
includes to your project:
#include "spi-arch.h
#include "dev/spi.h"
