From 7f17ad48b28a21af45f5b10ea3558392647ef179 Mon Sep 17 00:00:00 2001 From: gdisirio Date: Sat, 3 Jul 2010 07:17:29 +0000 Subject: [PATCH] AT91SAM7 SPI driver contributed by Alexander. git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@2049 35acf78f-673a-0410-8e92-d51de3d6d3f4 --- os/hal/platforms/AT91SAM7/platform.mk | 1 + os/hal/platforms/AT91SAM7/spi_lld.c | 226 ++++++++++++++++++++++++++ os/hal/platforms/AT91SAM7/spi_lld.h | 145 +++++++++++++++++ 3 files changed, 372 insertions(+) create mode 100644 os/hal/platforms/AT91SAM7/spi_lld.c create mode 100644 os/hal/platforms/AT91SAM7/spi_lld.h diff --git a/os/hal/platforms/AT91SAM7/platform.mk b/os/hal/platforms/AT91SAM7/platform.mk index a6293dfdd..9a5bba436 100644 --- a/os/hal/platforms/AT91SAM7/platform.mk +++ b/os/hal/platforms/AT91SAM7/platform.mk @@ -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 diff --git a/os/hal/platforms/AT91SAM7/spi_lld.c b/os/hal/platforms/AT91SAM7/spi_lld.c new file mode 100644 index 000000000..2353b76cb --- /dev/null +++ b/os/hal/platforms/AT91SAM7/spi_lld.c @@ -0,0 +1,226 @@ +/* + 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 . +*/ + +/** + * @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 */ + +/** @} */ diff --git a/os/hal/platforms/AT91SAM7/spi_lld.h b/os/hal/platforms/AT91SAM7/spi_lld.h new file mode 100644 index 000000000..529b284d2 --- /dev/null +++ b/os/hal/platforms/AT91SAM7/spi_lld.h @@ -0,0 +1,145 @@ +/* + 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 . +*/ + +/** + * @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_ */ + +/** @} */