324 lines
9.8 KiB
C
324 lines
9.8 KiB
C
/*
|
|
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 LPC214x/spi_lld.c
|
|
* @brief LPC214x low level SPI driver code.
|
|
*
|
|
* @addtogroup LPC214x_SPI
|
|
* @{
|
|
*/
|
|
|
|
#include "ch.h"
|
|
#include "hal.h"
|
|
|
|
#if CH_HAL_USE_SPI || defined(__DOXYGEN__)
|
|
|
|
/*===========================================================================*/
|
|
/* Driver exported variables. */
|
|
/*===========================================================================*/
|
|
|
|
#if LPC214x_SPI_USE_SSP || defined(__DOXYGEN__)
|
|
/** @brief SPI1 driver identifier.*/
|
|
SPIDriver SPID1;
|
|
#endif
|
|
|
|
/*===========================================================================*/
|
|
/* Driver local variables. */
|
|
/*===========================================================================*/
|
|
|
|
/*===========================================================================*/
|
|
/* Driver local functions. */
|
|
/*===========================================================================*/
|
|
|
|
/**
|
|
* @brief Preloads the transmit FIFO.
|
|
*
|
|
* @param[in] spip pointer to the @p SPIDriver object
|
|
*/
|
|
static void ssp_fifo_preload(SPIDriver *spip) {
|
|
SSP *ssp = spip->spd_ssp;
|
|
uint32_t n = spip->spd_txcnt > LPC214x_SSP_FIFO_DEPTH ?
|
|
LPC214x_SSP_FIFO_DEPTH : spip->spd_txcnt;
|
|
|
|
while(((ssp->SSP_SR & SR_TNF) != 0) && (n > 0)) {
|
|
if (spip->spd_txptr != NULL) {
|
|
if ((ssp->SSP_CR0 & CR0_DSSMASK) > CR0_DSS8BIT)
|
|
ssp->SSP_DR = *(uint16_t *)spip->spd_txptr++;
|
|
else
|
|
ssp->SSP_DR = *(uint8_t *)spip->spd_txptr++;
|
|
}
|
|
else
|
|
ssp->SSP_DR = 0xFFFFFFFF;
|
|
n--;
|
|
spip->spd_txcnt--;
|
|
}
|
|
}
|
|
|
|
#if defined(__GNUC__)
|
|
__attribute__((noinline))
|
|
#endif
|
|
/**
|
|
* @brief Common IRQ handler.
|
|
*
|
|
* @param[in] spip pointer to the @p SPIDriver object
|
|
*/
|
|
static void serve_interrupt(SPIDriver *spip) {
|
|
SSP *ssp = spip->spd_ssp;
|
|
|
|
if ((ssp->SSP_MIS & MIS_ROR) != 0) {
|
|
/* The overflow condition should never happen because priority is given
|
|
to receive but a hook macro is provided anyway...*/
|
|
LPC214x_SPI_SSP_ERROR_HOOK();
|
|
}
|
|
ssp->SSP_ICR = ICR_RT | ICR_ROR;
|
|
while ((ssp->SSP_SR & SR_RNE) != 0) {
|
|
if (spip->spd_rxptr != NULL) {
|
|
if ((ssp->SSP_CR0 & CR0_DSSMASK) > CR0_DSS8BIT)
|
|
*(uint16_t *)spip->spd_rxptr++ = ssp->SSP_DR;
|
|
else
|
|
*(uint8_t *)spip->spd_rxptr++ = ssp->SSP_DR;
|
|
}
|
|
else
|
|
(void)ssp->SSP_DR;
|
|
if (--spip->spd_rxcnt == 0) {
|
|
chDbgAssert(spip->spd_txcnt == 0,
|
|
"chSemResetI(), #1", "counter out of synch");
|
|
/* Stops the IRQ sources.*/
|
|
ssp->SSP_IMSC = 0;
|
|
/* Portable SPI ISR code defined in the high level driver, note, it is
|
|
a macro.*/
|
|
_spi_isr_code(spip);
|
|
return;
|
|
}
|
|
}
|
|
ssp_fifo_preload(spip);
|
|
if (spip->spd_txcnt == 0)
|
|
ssp->SSP_IMSC = IMSC_ROR | IMSC_RT | IMSC_RX;
|
|
}
|
|
|
|
/*===========================================================================*/
|
|
/* Driver interrupt handlers. */
|
|
/*===========================================================================*/
|
|
|
|
#if LPC214x_SPI_USE_SSP || defined(__DOXYGEN__)
|
|
/**
|
|
* @brief SPI1 interrupt handler.
|
|
*
|
|
* @isr
|
|
*/
|
|
CH_IRQ_HANDLER(SPI1IrqHandler) {
|
|
|
|
CH_IRQ_PROLOGUE();
|
|
|
|
serve_interrupt(&SPID1);
|
|
VICVectAddr = 0;
|
|
|
|
CH_IRQ_EPILOGUE();
|
|
}
|
|
#endif
|
|
|
|
/*===========================================================================*/
|
|
/* Driver exported functions. */
|
|
/*===========================================================================*/
|
|
|
|
/**
|
|
* @brief Low level SPI driver initialization.
|
|
*
|
|
* @notapi
|
|
*/
|
|
void spi_lld_init(void) {
|
|
|
|
#if LPC214x_SPI_USE_SSP
|
|
spiObjectInit(&SPID1);
|
|
SPID1.spd_ssp = SSPBase;
|
|
SetVICVector(SPI1IrqHandler, LPC214x_SPI_SSP_IRQ_PRIORITY, SOURCE_SPI1);
|
|
#endif
|
|
}
|
|
|
|
/**
|
|
* @brief Configures and activates the SPI peripheral.
|
|
*
|
|
* @param[in] spip pointer to the @p SPIDriver object
|
|
*
|
|
* @notapi
|
|
*/
|
|
void spi_lld_start(SPIDriver *spip) {
|
|
|
|
if (spip->spd_state == SPI_STOP) {
|
|
/* Clock activation.*/
|
|
#if LPC214x_SPI_USE_SSP
|
|
if (&SPID1 == spip) {
|
|
PCONP = (PCONP & PCALL) | PCSPI1;
|
|
VICIntEnable = INTMASK(SOURCE_SPI1);
|
|
}
|
|
#endif
|
|
}
|
|
/* Configuration.*/
|
|
spip->spd_ssp->SSP_CR1 = 0;
|
|
/* Emptying the receive FIFO, it happens to not be empty while debugging.*/
|
|
while (spip->spd_ssp->SSP_SR & SR_RNE)
|
|
(void) spip->spd_ssp->SSP_DR;
|
|
spip->spd_ssp->SSP_ICR = ICR_RT | ICR_ROR;
|
|
spip->spd_ssp->SSP_CR0 = spip->spd_config->spc_cr0;
|
|
spip->spd_ssp->SSP_CPSR = spip->spd_config->spc_cpsr;
|
|
spip->spd_ssp->SSP_CR1 = spip->spd_config->spc_cr1 | CR1_SSE;
|
|
}
|
|
|
|
/**
|
|
* @brief Deactivates the SPI peripheral.
|
|
*
|
|
* @param[in] spip pointer to the @p SPIDriver object
|
|
*
|
|
* @notapi
|
|
*/
|
|
void spi_lld_stop(SPIDriver *spip) {
|
|
|
|
if (spip->spd_state != SPI_STOP) {
|
|
#if LPC214x_SPI_USE_SSP
|
|
if (&SPID1 == spip) {
|
|
PCONP = (PCONP & PCALL) & ~PCSPI1;
|
|
VICIntEnClear = INTMASK(SOURCE_SPI1);
|
|
}
|
|
#endif
|
|
spip->spd_ssp->SSP_CR1 = 0;
|
|
spip->spd_ssp->SSP_CR0 = 0;
|
|
spip->spd_ssp->SSP_CPSR = 0;
|
|
PCONP &= ~PCSPI1;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @brief Asserts the slave select signal and prepares for transfers.
|
|
*
|
|
* @param[in] spip pointer to the @p SPIDriver object
|
|
*
|
|
* @notapi
|
|
*/
|
|
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
|
|
*
|
|
* @notapi
|
|
*/
|
|
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
|
|
*
|
|
* @notapi
|
|
*/
|
|
void spi_lld_ignore(SPIDriver *spip, size_t n) {
|
|
|
|
spip->spd_rxptr = NULL;
|
|
spip->spd_txptr = NULL;
|
|
spip->spd_rxcnt = spip->spd_txcnt = n;
|
|
ssp_fifo_preload(spip);
|
|
spip->spd_ssp->SSP_IMSC = IMSC_ROR | IMSC_RT | IMSC_TX | IMSC_RX;
|
|
}
|
|
|
|
/**
|
|
* @brief Exchanges data on the SPI bus.
|
|
* @details This asynchronous function starts a simultaneous transmit/receive
|
|
* operation.
|
|
* @post At the end of the operation the configured callback is invoked.
|
|
* @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.
|
|
*
|
|
* @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
|
|
*
|
|
* @notapi
|
|
*/
|
|
void spi_lld_exchange(SPIDriver *spip, size_t n,
|
|
const void *txbuf, void *rxbuf) {
|
|
|
|
spip->spd_rxptr = rxbuf;
|
|
spip->spd_txptr = txbuf;
|
|
spip->spd_rxcnt = spip->spd_txcnt = n;
|
|
ssp_fifo_preload(spip);
|
|
spip->spd_ssp->SSP_IMSC = IMSC_ROR | IMSC_RT | IMSC_TX | IMSC_RX;
|
|
}
|
|
|
|
/**
|
|
* @brief Sends data over the SPI bus.
|
|
* @details This asynchronous function starts a transmit operation.
|
|
* @post At the end of the operation the configured callback is invoked.
|
|
* @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.
|
|
*
|
|
* @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
|
|
*
|
|
* @notapi
|
|
*/
|
|
void spi_lld_send(SPIDriver *spip, size_t n, const void *txbuf) {
|
|
|
|
spip->spd_rxptr = NULL;
|
|
spip->spd_txptr = txbuf;
|
|
spip->spd_rxcnt = spip->spd_txcnt = n;
|
|
ssp_fifo_preload(spip);
|
|
spip->spd_ssp->SSP_IMSC = IMSC_ROR | IMSC_RT | IMSC_TX | IMSC_RX;
|
|
}
|
|
|
|
/**
|
|
* @brief Receives data from the SPI bus.
|
|
* @details This asynchronous function starts a receive operation.
|
|
* @post At the end of the operation the configured callback is invoked.
|
|
* @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.
|
|
*
|
|
* @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
|
|
*
|
|
* @notapi
|
|
*/
|
|
void spi_lld_receive(SPIDriver *spip, size_t n, void *rxbuf) {
|
|
|
|
spip->spd_rxptr = rxbuf;
|
|
spip->spd_txptr = NULL;
|
|
spip->spd_rxcnt = spip->spd_txcnt = n;
|
|
ssp_fifo_preload(spip);
|
|
spip->spd_ssp->SSP_IMSC = IMSC_ROR | IMSC_RT | IMSC_TX | IMSC_RX;
|
|
}
|
|
|
|
#endif /* CH_HAL_USE_SPI */
|
|
|
|
/** @} */
|