8b57670121
This changes makes it possible to change the SPI clock frequency at runtime. Signed-off-by: Benoît Thébaudeau <benoit@wsystem.com>
223 lines
7.8 KiB
C
223 lines
7.8 KiB
C
/*
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* Copyright (c) 2013, University of Michigan.
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*
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* Copyright (c) 2015, Weptech elektronik GmbH
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* Author: Ulf Knoblich, ulf.knoblich@weptech.de
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*
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/**
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* \addtogroup cc2538-spi
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* @{
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*
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* \file
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* Header file for the cc2538 SPI driver, including macros for the
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* implementation of the low-level SPI primitives such as waiting for the TX
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* FIFO to be ready, inserting into the TX FIFO, etc.
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*
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* It supports the usage of SSI_NUM_INSTANCES instances by providing new
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* functions calls like
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*
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* - spix_init(uint8_t instance)
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* - spix_enable(uint8_t instance)
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* - spix_disable(uint8_t instance)
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* - spix_set_mode(unit8_t instance, ...)
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*
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* and new macros like
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*
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* - SPIX_WAITFORTxREADY(x)
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* - SPIX_WAITFOREOTx(x)
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* - SPIX_WAITFOREORx(x)
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* - SPIX_FLUSH(x)
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*
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* Some of the old functions and macros are still supported.
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* When using these deprecated functions, the SSI module to use
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* has to be be selected by means of the macro SPI_CONF_DEFAULT_INSTANCE.
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*
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* This SPI driver depends on the following defines:
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*
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* For the SSI0 module:
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*
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* - SPI0_CKL_PORT
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* - SPI0_CLK_PIN
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* - SPI0_TX_PORT
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* - SPI0_TX_PIN
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* - SPI0_RX_PORT
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* - SPI0_RX_PIN
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*
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* For the SSI1 module:
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*
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* - SPI1_CKL_PORT
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* - SPI1_CLK_PIN
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* - SPI1_TX_PORT
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* - SPI1_TX_PIN
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* - SPI1_RX_PORT
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* - SPI1_RX_PIN
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*/
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#ifndef SPI_ARCH_H_
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#define SPI_ARCH_H_
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#include "contiki.h"
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#include "dev/ssi.h"
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/*---------------------------------------------------------------------------*/
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/* The SPI instance to use when using the deprecated SPI API. */
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#ifdef SPI_CONF_DEFAULT_INSTANCE
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#if SPI_CONF_DEFAULT_INSTANCE > (SSI_INSTANCE_COUNT - 1)
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#error Invalid SPI_CONF_DEFAULT_INSTANCE: valid values are 0 and 1
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#else
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#define SPI_DEFAULT_INSTANCE SPI_CONF_DEFAULT_INSTANCE
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#endif
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#endif
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/*---------------------------------------------------------------------------*/
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/* Default values for the clock rate divider */
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#ifdef SPI0_CONF_CPRS_CPSDVSR
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#define SPI0_CPRS_CPSDVSR SPI0_CONF_CPRS_CPSDVSR
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#else
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#define SPI0_CPRS_CPSDVSR 2
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#endif
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#ifdef SPI1_CONF_CPRS_CPSDVSR
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#define SPI1_CPRS_CPSDVSR SPI1_CONF_CPRS_CPSDVSR
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#else
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#define SPI1_CPRS_CPSDVSR 2
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#endif
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/*---------------------------------------------------------------------------*/
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/* New API macros */
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#define SPIX_WAITFORTxREADY(spi) do { \
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while(!(REG(SSI_BASE(spi) + SSI_SR) & SSI_SR_TNF)) ; \
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} while(0)
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#define SPIX_BUF(spi) REG(SSI_BASE(spi) + SSI_DR)
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#define SPIX_WAITFOREOTx(spi) do { \
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while(REG(SSI_BASE(spi) + SSI_SR) & SSI_SR_BSY) ; \
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} while(0)
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#define SPIX_WAITFOREORx(spi) do { \
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while(!(REG(SSI_BASE(spi) + SSI_SR) & SSI_SR_RNE)) ; \
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} while(0)
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#define SPIX_FLUSH(spi) do { \
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while(REG(SSI_BASE(spi) + SSI_SR) & SSI_SR_RNE) { \
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SPIX_BUF(spi); \
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} \
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} while(0)
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#define SPIX_CS_CLR(port, pin) do { \
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GPIO_CLR_PIN(GPIO_PORT_TO_BASE(port), GPIO_PIN_MASK(pin)); \
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} while(0)
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#define SPIX_CS_SET(port, pin) do { \
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GPIO_SET_PIN(GPIO_PORT_TO_BASE(port), GPIO_PIN_MASK(pin)); \
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} while(0)
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/*---------------------------------------------------------------------------*/
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/* Deprecated macros provided for compatibility reasons */
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#ifdef SPI_DEFAULT_INSTANCE
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#define SPI_WAITFORTxREADY() SPIX_WAITFORTxREADY(SPI_DEFAULT_INSTANCE)
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#define SPI_TXBUF SPIX_BUF(SPI_DEFAULT_INSTANCE)
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#define SPI_RXBUF SPI_TXBUF
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#define SPI_WAITFOREOTx() SPIX_WAITFOREOTx(SPI_DEFAULT_INSTANCE)
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#define SPI_WAITFOREORx() SPIX_WAITFOREORx(SPI_DEFAULT_INSTANCE)
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#ifdef SPI_FLUSH
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#error You must include spi-arch.h before spi.h for the CC2538
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#else
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#define SPI_FLUSH() SPIX_FLUSH(SPI_DEFAULT_INSTANCE)
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#endif
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#define SPI_CS_CLR(port, pin) SPIX_CS_CLR(port, pin)
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#define SPI_CS_SET(port, pin) SPIX_CS_SET(port, pin)
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#endif /* #ifdef SPI_DEFAULT_INSTANCE */
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/*---------------------------------------------------------------------------*/
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/** \name Arch-specific SPI functions
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* @{
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*/
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/**
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* \brief Initialize the SPI bus for the instance given
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*
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* This sets the mode to Motorola SPI with the following format options:
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* Clock phase: 1; data captured on second (rising) edge
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* Clock polarity: 1; clock is high when idle
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* Data size: 8 bits
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*
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* Use spix_set_mode() to change the spi mode.
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*/
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void spix_init(uint8_t spi);
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/**
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* \brief Enables the SPI peripheral for the instance given
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*/
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void spix_enable(uint8_t spi);
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/**
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* \brief Disables the SPI peripheral for the instance given
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* \note Call this function to save power when the SPI is unused.
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*/
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void spix_disable(uint8_t spi);
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/**
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* \brief Configure the SPI data and clock polarity and the data size for the
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* instance given
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*
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* This function configures the SSI peripheral to use a particular SPI
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* configuration that a slave device requires. It should always be called
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* before using the SPI bus as another driver could have changed the settings.
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*
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* See section 19.4.4 in the CC2538 user guide for more information.
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*
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* \param spi The SSI instance to use.
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* \param frame_format Set the SSI frame format. Use SSI_CR0_FRF_MOTOROLA,
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* SSI_CR0_FRF_TI, or SSI_CR0_FRF_MICROWIRE.
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* \param clock_polarity In Motorola mode, set whether the clock is high or low
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* when idle. Use SSI_CR0_SPO or 0.
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* \param clock_phase In Motorola mode, select whether data is valid on the
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* first or second edge of the clock. Use SSI_CR0_SPH or 0.
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* \param data_size The number of bits in each "byte" of data. Must be
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* between 4 and 16, inclusive.
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*/
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void spix_set_mode(uint8_t spi, uint32_t frame_format,
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uint32_t clock_polarity, uint32_t clock_phase,
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uint32_t data_size);
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/**
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* \brief Sets the SPI clock frequency of the given SSI instance.
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*
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* \param spi SSI instance
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* \param freq Frequency (Hz)
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*/
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void spix_set_clock_freq(uint8_t spi, uint32_t freq);
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/**
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* \brief Configure a GPIO to be the chip select pin.
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*
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* Even if this function does not depend on the SPI instance used, we rename
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* it to reflect the new naming convention.
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*/
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void spix_cs_init(uint8_t port, uint8_t pin);
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/** @} */
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#endif /* SPI_ARCH_H_ */
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/**
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* @}
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*/
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