contiki/cpu/cc2538/spi-arch.h
2015-02-16 10:17:58 +01:00

123 lines
4.2 KiB
C

/*
* Copyright (c) 2013, University of Michigan.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/**
* \addtogroup cc2538-spi
* @{
*
* \file
* Header file for the cc2538 SPI driver, including macros for the
* implementation of the low-level SPI primitives such as waiting for the TX
* FIFO to be ready, inserting into the TX FIFO, etc.
*/
#ifndef SPI_ARCH_H_
#define SPI_ARCH_H_
#include "dev/ssi.h"
#define SPI_WAITFORTxREADY() do { \
while(!(REG(SSI0_BASE + SSI_SR) & SSI_SR_TNF)); \
} while(0)
#define SPI_TXBUF REG(SSI0_BASE + SSI_DR)
#define SPI_RXBUF REG(SSI0_BASE + SSI_DR)
#define SPI_WAITFOREOTx() do { \
while(REG(SSI0_BASE + SSI_SR) & SSI_SR_BSY); \
} while(0)
#define SPI_WAITFOREORx() do { \
while(!(REG(SSI0_BASE + SSI_SR) & SSI_SR_RNE)); \
} while(0)
#ifdef SPI_FLUSH
#error "You must include spi-arch.h before spi.h for the CC2538."
#endif
#define SPI_FLUSH() do { \
SPI_WAITFOREORx(); \
while (REG(SSI0_BASE + SSI_SR) & SSI_SR_RNE) { \
SPI_RXBUF; \
} \
} while(0)
#define SPI_CS_CLR(port, pin) do { \
GPIO_CLR_PIN(GPIO_PORT_TO_BASE(port), GPIO_PIN_MASK(pin)); \
} while(0)
#define SPI_CS_SET(port, pin) do { \
GPIO_SET_PIN(GPIO_PORT_TO_BASE(port), GPIO_PIN_MASK(pin)); \
} while(0)
/*---------------------------------------------------------------------------*/
/** \name Arch-specific SPI functions
* @{
*/
/**
* \brief Configure a GPIO to be the chip select pin
*/
void spi_cs_init(uint8_t port, uint8_t pin);
/** \brief Enables the SPI peripheral
*/
void spi_enable(void);
/** \brief Disables the SPI peripheral
* \note Call this function to save power when the SPI is unused.
*/
void spi_disable(void);
/**
* \brief Configure the SPI data and clock polarity and the data size.
*
* This function configures the SSI peripheral to use a particular SPI
* configuration that a slave device requires. It should always be called
* before using the SPI bus as another driver could have changed the settings.
*
* See section 19.4.4 in the CC2538 user guide for more information.
*
* \param frame_format Set the SSI frame format. Use SSI_CR0_FRF_MOTOROLA,
* SSI_CR0_FRF_TI, or SSI_CR0_FRF_MICROWIRE.
* \param clock_polarity In Motorola mode, set whether the clock is high or low
* when idle. Use SSI_CR0_SPO or 0.
* \param clock_phase In Motorola mode, select whether data is valid on the
* first or second edge of the clock. Use SSI_CR0_SPH or 0.
* \param data_size The number of bits in each "byte" of data. Must be
* between 4 and 16, inclusive.
*/
void spi_set_mode(uint32_t frame_format, uint32_t clock_polarity,
uint32_t clock_phase, uint32_t data_size);
/** @} */
#endif /* SPI_ARCH_H_ */
/**
* @}
*/