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AT91SAM7 SPI driver contributed by Alexander. 

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@2049 35acf78f-673a-0410-8e92-d51de3d6d3f4
This commit is contained in:
gdisirio 2010-07-03 07:17:29 +00:00
parent cffbb9b25b
commit 7f17ad48b2
3 changed files with 372 additions and 0 deletions
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1
os/hal/platforms/AT91SAM7/platform.mk
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@ -2,6 +2,7 @@
PLATFORMSRC = ${CHIBIOS}/os/hal/platforms/AT91SAM7/hal_lld.c \
${CHIBIOS}/os/hal/platforms/AT91SAM7/pal_lld.c \
${CHIBIOS}/os/hal/platforms/AT91SAM7/serial_lld.c \
${CHIBIOS}/os/hal/platforms/AT91SAM7/spi_lld.c \
${CHIBIOS}/os/hal/platforms/AT91SAM7/mac_lld.c \
${CHIBIOS}/os/hal/platforms/AT91SAM7/at91sam7_mii.c \
${CHIBIOS}/os/hal/platforms/AT91SAM7/at91lib/aic.c

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os/hal/platforms/AT91SAM7/spi_lld.c Normal file
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/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file AT91SAM7/spi_lld.c
* @brief AT91SAM7 low level SPI driver code.
* @addtogroup AT91SAM7_SPI
* @{
*/
#include "ch.h"
#include "hal.h"
#if CH_HAL_USE_SPI || defined(__DOXYGEN__)
/*===========================================================================*/
/* Driver exported variables. */
/*===========================================================================*/
#if USE_AT91SAM7_SPI || defined(__DOXYGEN__)
/** @brief SPI driver identifier.*/
SPIDriver SPID;
#endif
/*===========================================================================*/
/* Driver local variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver local functions. */
/*===========================================================================*/
/**
* @brief Synchronous SPI transfer.
*
* @param[in] n number of bytes to be exchanged
*
* @param[in] txbuf the pointer to the transmit buffer or @p NULL
* @param[out] rxbuf the pointer to the receive buffer or @p NULL
*/
void rw8(size_t n, const uint8_t *txbuf, uint8_t *rxbuf) {
size_t ntx = n;
while (n > 0) {
uint32_t sr = AT91C_BASE_SPI->SPI_SR;
if (sr & AT91C_SPI_RDRF) {
uint8_t w = AT91C_BASE_SPI->SPI_RDR;
if (rxbuf != NULL)
*rxbuf++ = w;
n--;
continue; /* Priority over transmission. */
}
if ((ntx > 0) && (sr & AT91C_SPI_TDRE)) {
if (txbuf != NULL)
AT91C_BASE_SPI->SPI_TDR = *txbuf++;
else
AT91C_BASE_SPI->SPI_TDR = 0xFF;
ntx--;
}
}
}
/*===========================================================================*/
/* Driver interrupt handlers. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver exported functions. */
/*===========================================================================*/
/**
* @brief Low level SPI driver initialization.
*/
void spi_lld_init(void) {
#if USE_AT91SAM7_SPI
spiObjectInit(&SPID);
#endif
}
/**
* @brief Configures and activates the SPI peripheral.
*
* @param[in] spip pointer to the @p SPIDriver object
*/
void spi_lld_start(SPIDriver *spip) {
if (spip->spd_state == SPI_STOP) {
/* disable general-purpose I/O for SPI pins */
AT91C_BASE_PIOA->PIO_PDR = SPI_MISO | SPI_MOSI | SPI_SCK;
/* select perepheral A for SPI pins*/
AT91C_BASE_PIOA->PIO_ASR = SPI_MISO | SPI_MOSI | SPI_SCK;
/* Clock activation.*/
AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_SPI);
}
/* software reset must be written twice (errata for revision B parts) */
AT91C_BASE_SPI->SPI_CR = AT91C_SPI_SWRST;
AT91C_BASE_SPI->SPI_CR = AT91C_SPI_SWRST;
/* Configuration.*/
AT91C_BASE_SPI->SPI_MR = spip->spd_config->spc_mr;
AT91C_BASE_SPI->SPI_CSR[MMC_CSR_NUM] = spip->spd_config->spc_csr;
/* Enable SPI */
AT91C_BASE_SPI->SPI_CR = AT91C_SPI_SPIEN;
}
/**
* @brief Deactivates the SPI peripheral.
*
* @param[in] spip pointer to the @p SPIDriver object
*/
void spi_lld_stop(SPIDriver *spip) {
if (spip->spd_state != SPI_STOP) {
/* disable SPI */
AT91C_BASE_SPI->SPI_CR = AT91C_SPI_SPIDIS;
/* disable clocks to SPI perepheral */
AT91C_BASE_PMC->PMC_PCDR = (1 << AT91C_ID_SPI);
}
}
/**
* @brief Asserts the slave select signal and prepares for transfers.
*
* @param[in] spip pointer to the @p SPIDriver object
*/
void spi_lld_select(SPIDriver *spip) {
palClearPad(spip->spd_config->spc_ssport, spip->spd_config->spc_sspad);
}
/**
* @brief Deasserts the slave select signal.
* @details The previously selected peripheral is unselected.
*
* @param[in] spip pointer to the @p SPIDriver object
*/
void spi_lld_unselect(SPIDriver *spip) {
palSetPad(spip->spd_config->spc_ssport, spip->spd_config->spc_sspad);
}
/**
* @brief Ignores data on the SPI bus.
* @details This function transmits a series of idle words on the SPI bus and
* ignores the received data. This function can be invoked even
* when a slave select signal has not been yet asserted.
*
* @param[in] spip pointer to the @p SPIDriver object
* @param[in] n number of words to be ignored
*/
void spi_lld_ignore(SPIDriver *spip, size_t n) {
(void)spip;
rw8(n, NULL, NULL);
}
/**
* @brief Exchanges data on the SPI bus.
* @details This function performs a simultaneous transmit/receive operation.
*
* @param[in] spip pointer to the @p SPIDriver object
* @param[in] n number of words to be exchanged
* @param[in] txbuf the pointer to the transmit buffer
* @param[out] rxbuf the pointer to the receive buffer
*
* @note The buffers are organized as uint8_t arrays for data sizes below or
* equal to 8 bits else it is organized as uint16_t arrays.
*/
void spi_lld_exchange(SPIDriver *spip, size_t n,
const void *txbuf, void *rxbuf) {
(void)spip;
rw8(n, txbuf, rxbuf);
}
/**
* @brief Sends data over the SPI bus.
*
* @param[in] spip pointer to the @p SPIDriver object
* @param[in] n number of words to send
* @param[in] txbuf the pointer to the transmit buffer
*
* @note The buffers are organized as uint8_t arrays for data sizes below or
* equal to 8 bits else it is organized as uint16_t arrays.
*/
void spi_lld_send(SPIDriver *spip, size_t n, const void *txbuf) {
(void)spip;
rw8(n, txbuf, NULL);
}
/**
* @brief Receives data from the SPI bus.
*
* @param[in] spip pointer to the @p SPIDriver object
* @param[in] n number of words to receive
* @param[out] rxbuf the pointer to the receive buffer
*
* @note The buffers are organized as uint8_t arrays for data sizes below or
* equal to 8 bits else it is organized as uint16_t arrays.
*/
void spi_lld_receive(SPIDriver *spip, size_t n, void *rxbuf) {
(void)spip;
rw8(n, NULL, rxbuf);
}
#endif /* CH_HAL_USE_SPI */
/** @} */

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os/hal/platforms/AT91SAM7/spi_lld.h Normal file
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/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file AT91SAM7/spi_lld.h
* @brief AT91SAM7 low level SPI driver header.
* @addtogroup AT91SAM7_SPI
* @{
*/
#ifndef _SPI_LLD_H_
#define _SPI_LLD_H_
#if CH_HAL_USE_SPI || defined(__DOXYGEN__)
/*===========================================================================*/
/* Device compatibility. SAM7X have 2 SPIs. */
/*===========================================================================*/
#if defined (AT91SAM7X256_H)
#define AT91C_BASE_SPI AT91C_BASE_SPI0
#define AT91C_ID_SPI AT91C_ID_SPI0
#endif
/*===========================================================================*/
/* Driver constants. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver pre-compile time settings. */
/*===========================================================================*/
/**
* @brief SPI driver enable switch.
* @details If set to @p TRUE the support for SPI0 is included.
* @note The default is @p TRUE.
*/
#if !defined(USE_AT91SAM7_SPI) || defined(__DOXYGEN__)
#define USE_AT91SAM7_SPI TRUE
#endif
/*===========================================================================*/
/* Derived constants and error checks. */
/*===========================================================================*/
/*===========================================================================*/
/* Driver data structures and types. */
/*===========================================================================*/
/**
* @brief Driver configuration structure.
*/
typedef struct {
/**
* @brief The chip select line port.
*/
ioportid_t spc_ssport;
/**
* @brief The chip select line pad number.
*/
uint16_t spc_sspad;
/**
* @brief SPI Mode Register initialization data.
*/
uint32_t spc_mr;
/**
* @brief SPI Chip Select Register initialization data.
*/
uint32_t spc_csr;
} SPIConfig;
/**
* @brief Structure representing a SPI driver.
*/
typedef struct {
/**
* @brief Driver state.
*/
spistate_t spd_state;
#if SPI_USE_MUTUAL_EXCLUSION || defined(__DOXYGEN__)
#if CH_USE_MUTEXES || defined(__DOXYGEN__)
/**
* @brief Mutex protecting the bus.
*/
Mutex spd_mutex;
#elif CH_USE_SEMAPHORES
Semaphore spd_semaphore;
#endif
#endif /* SPI_USE_MUTUAL_EXCLUSION */
/**
* @brief Current configuration data.
*/
const SPIConfig *spd_config;
/* End of the mandatory fields.*/
} SPIDriver;
/*===========================================================================*/
/* Driver macros. */
/*===========================================================================*/
/*===========================================================================*/
/* External declarations. */
/*===========================================================================*/
#if USE_AT91SAM7_SPI && !defined(__DOXYGEN__)
extern SPIDriver SPID;
#endif
#ifdef __cplusplus
extern "C" {
#endif
void spi_lld_init(void);
void spi_lld_start(SPIDriver *spip);
void spi_lld_stop(SPIDriver *spip);
void spi_lld_select(SPIDriver *spip);
void spi_lld_unselect(SPIDriver *spip);
void spi_lld_ignore(SPIDriver *spip, size_t n);
void spi_lld_exchange(SPIDriver *spip, size_t n,
const void *txbuf, void *rxbuf);
void spi_lld_send(SPIDriver *spip, size_t n, const void *txbuf);
void spi_lld_receive(SPIDriver *spip, size_t n, void *rxbuf);
#ifdef __cplusplus
}
#endif
#endif /* CH_HAL_USE_SPI */
#endif /* _SPI_LLD_H_ */
/** @} */