contiki/cpu/cc2538/spi-arch.h
Benoît Thébaudeau 8b57670121 cc2538: spi: Add support for dynamic clock frequency
This changes makes it possible to change the SPI clock frequency at
runtime.

Signed-off-by: Benoît Thébaudeau <benoit@wsystem.com>
2016-11-27 22:50:43 +01:00

223 lines
7.8 KiB
C

/*
* Copyright (c) 2013, University of Michigan.
*
* Copyright (c) 2015, Weptech elektronik GmbH
* Author: Ulf Knoblich, ulf.knoblich@weptech.de
*
* 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.
*
* It supports the usage of SSI_NUM_INSTANCES instances by providing new
* functions calls like
*
* - spix_init(uint8_t instance)
* - spix_enable(uint8_t instance)
* - spix_disable(uint8_t instance)
* - spix_set_mode(unit8_t instance, ...)
*
* and new macros like
*
* - SPIX_WAITFORTxREADY(x)
* - SPIX_WAITFOREOTx(x)
* - SPIX_WAITFOREORx(x)
* - SPIX_FLUSH(x)
*
* Some of the old functions and macros are still supported.
* When using these deprecated functions, the SSI module to use
* has to be be selected by means of the macro SPI_CONF_DEFAULT_INSTANCE.
*
* This SPI driver depends on the following defines:
*
* For the SSI0 module:
*
* - SPI0_CKL_PORT
* - SPI0_CLK_PIN
* - SPI0_TX_PORT
* - SPI0_TX_PIN
* - SPI0_RX_PORT
* - SPI0_RX_PIN
*
* For the SSI1 module:
*
* - SPI1_CKL_PORT
* - SPI1_CLK_PIN
* - SPI1_TX_PORT
* - SPI1_TX_PIN
* - SPI1_RX_PORT
* - SPI1_RX_PIN
*/
#ifndef SPI_ARCH_H_
#define SPI_ARCH_H_
#include "contiki.h"
#include "dev/ssi.h"
/*---------------------------------------------------------------------------*/
/* The SPI instance to use when using the deprecated SPI API. */
#ifdef SPI_CONF_DEFAULT_INSTANCE
#if SPI_CONF_DEFAULT_INSTANCE > (SSI_INSTANCE_COUNT - 1)
#error Invalid SPI_CONF_DEFAULT_INSTANCE: valid values are 0 and 1
#else
#define SPI_DEFAULT_INSTANCE SPI_CONF_DEFAULT_INSTANCE
#endif
#endif
/*---------------------------------------------------------------------------*/
/* Default values for the clock rate divider */
#ifdef SPI0_CONF_CPRS_CPSDVSR
#define SPI0_CPRS_CPSDVSR SPI0_CONF_CPRS_CPSDVSR
#else
#define SPI0_CPRS_CPSDVSR 2
#endif
#ifdef SPI1_CONF_CPRS_CPSDVSR
#define SPI1_CPRS_CPSDVSR SPI1_CONF_CPRS_CPSDVSR
#else
#define SPI1_CPRS_CPSDVSR 2
#endif
/*---------------------------------------------------------------------------*/
/* New API macros */
#define SPIX_WAITFORTxREADY(spi) do { \
while(!(REG(SSI_BASE(spi) + SSI_SR) & SSI_SR_TNF)) ; \
} while(0)
#define SPIX_BUF(spi) REG(SSI_BASE(spi) + SSI_DR)
#define SPIX_WAITFOREOTx(spi) do { \
while(REG(SSI_BASE(spi) + SSI_SR) & SSI_SR_BSY) ; \
} while(0)
#define SPIX_WAITFOREORx(spi) do { \
while(!(REG(SSI_BASE(spi) + SSI_SR) & SSI_SR_RNE)) ; \
} while(0)
#define SPIX_FLUSH(spi) do { \
while(REG(SSI_BASE(spi) + SSI_SR) & SSI_SR_RNE) { \
SPIX_BUF(spi); \
} \
} while(0)
#define SPIX_CS_CLR(port, pin) do { \
GPIO_CLR_PIN(GPIO_PORT_TO_BASE(port), GPIO_PIN_MASK(pin)); \
} while(0)
#define SPIX_CS_SET(port, pin) do { \
GPIO_SET_PIN(GPIO_PORT_TO_BASE(port), GPIO_PIN_MASK(pin)); \
} while(0)
/*---------------------------------------------------------------------------*/
/* Deprecated macros provided for compatibility reasons */
#ifdef SPI_DEFAULT_INSTANCE
#define SPI_WAITFORTxREADY() SPIX_WAITFORTxREADY(SPI_DEFAULT_INSTANCE)
#define SPI_TXBUF SPIX_BUF(SPI_DEFAULT_INSTANCE)
#define SPI_RXBUF SPI_TXBUF
#define SPI_WAITFOREOTx() SPIX_WAITFOREOTx(SPI_DEFAULT_INSTANCE)
#define SPI_WAITFOREORx() SPIX_WAITFOREORx(SPI_DEFAULT_INSTANCE)
#ifdef SPI_FLUSH
#error You must include spi-arch.h before spi.h for the CC2538
#else
#define SPI_FLUSH() SPIX_FLUSH(SPI_DEFAULT_INSTANCE)
#endif
#define SPI_CS_CLR(port, pin) SPIX_CS_CLR(port, pin)
#define SPI_CS_SET(port, pin) SPIX_CS_SET(port, pin)
#endif /* #ifdef SPI_DEFAULT_INSTANCE */
/*---------------------------------------------------------------------------*/
/** \name Arch-specific SPI functions
* @{
*/
/**
* \brief Initialize the SPI bus for the instance given
*
* This sets the mode to Motorola SPI with the following format options:
* Clock phase: 1; data captured on second (rising) edge
* Clock polarity: 1; clock is high when idle
* Data size: 8 bits
*
* Use spix_set_mode() to change the spi mode.
*/
void spix_init(uint8_t spi);
/**
* \brief Enables the SPI peripheral for the instance given
*/
void spix_enable(uint8_t spi);
/**
* \brief Disables the SPI peripheral for the instance given
* \note Call this function to save power when the SPI is unused.
*/
void spix_disable(uint8_t spi);
/**
* \brief Configure the SPI data and clock polarity and the data size for the
* instance given
*
* 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 spi The SSI instance to use.
* \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 spix_set_mode(uint8_t spi, uint32_t frame_format,
uint32_t clock_polarity, uint32_t clock_phase,
uint32_t data_size);
/**
* \brief Sets the SPI clock frequency of the given SSI instance.
*
* \param spi SSI instance
* \param freq Frequency (Hz)
*/
void spix_set_clock_freq(uint8_t spi, uint32_t freq);
/**
* \brief Configure a GPIO to be the chip select pin.
*
* Even if this function does not depend on the SPI instance used, we rename
* it to reflect the new naming convention.
*/
void spix_cs_init(uint8_t port, uint8_t pin);
/** @} */
#endif /* SPI_ARCH_H_ */
/**
* @}
*/