diff options
Diffstat (limited to 'os/hal/platforms/LPC43xx/spi_lld.c')
| -rw-r--r-- | os/hal/platforms/LPC43xx/spi_lld.c | 383 |
1 files changed, 383 insertions, 0 deletions
diff --git a/os/hal/platforms/LPC43xx/spi_lld.c b/os/hal/platforms/LPC43xx/spi_lld.c new file mode 100644 index 000000000..3b394466c --- /dev/null +++ b/os/hal/platforms/LPC43xx/spi_lld.c @@ -0,0 +1,383 @@ +/* + ChibiOS/RT - Copyright (C) 2006-2013 Giovanni Di Sirio + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +/** + * @file LPC43xx/spi_lld.c + * @brief LPC43xx low level SPI driver code. + * + * @addtogroup SPI + * @{ + */ + +#include "ch.h" +#include "hal.h" + +#if HAL_USE_SPI || defined(__DOXYGEN__) + +/*===========================================================================*/ +/* Driver exported variables. */ +/*===========================================================================*/ + +#if LPC_SPI_USE_SSP0 || defined(__DOXYGEN__) +/** @brief SPI1 driver identifier.*/ +SPIDriver SPID1; +#endif + +#if LPC_SPI_USE_SSP1 || defined(__DOXYGEN__) +/** @brief SPI2 driver identifier.*/ +SPIDriver SPID2; +#endif + +/*===========================================================================*/ +/* Driver local variables and types. */ +/*===========================================================================*/ + +/*===========================================================================*/ +/* Driver local functions. */ +/*===========================================================================*/ + +/** + * @brief Preloads the transmit FIFO. + * + * @param[in] spip pointer to the @p SPIDriver object + */ +static void ssp_fifo_preload(SPIDriver *spip) { + LPC_SSPn_Type *ssp = spip->ssp; + uint32_t n = spip->txcnt > LPC_SSP_FIFO_DEPTH ? + LPC_SSP_FIFO_DEPTH : spip->txcnt; + + while(((ssp->SR & SR_TNF) != 0) && (n > 0)) { + if (spip->txptr != NULL) { + if ((ssp->CR0 & CR0_DSSMASK) > CR0_DSS8BIT) { + const uint16_t *p = spip->txptr; + ssp->DR = *p++; + spip->txptr = p; + } + else { + const uint8_t *p = spip->txptr; + ssp->DR = *p++; + spip->txptr = p; + } + } + else + ssp->DR = 0xFFFFFFFF; + n--; + spip->txcnt--; + } +} + +/** + * @brief Common IRQ handler. + * + * @param[in] spip pointer to the @p SPIDriver object + */ +static void spi_serve_interrupt(SPIDriver *spip) { + LPC_SSPn_Type *ssp = spip->ssp; + + if ((ssp->MIS & MIS_ROR) != 0) { + /* The overflow condition should never happen because priority is given + to receive but a hook macro is provided anyway...*/ + LPC_SPI_SSP_ERROR_HOOK(spip); + } + ssp->ICR = ICR_RT | ICR_ROR; + while ((ssp->SR & SR_RNE) != 0) { + if (spip->rxptr != NULL) { + if ((ssp->CR0 & CR0_DSSMASK) > CR0_DSS8BIT) { + uint16_t *p = spip->rxptr; + *p++ = ssp->DR; + spip->rxptr = p; + } + else { + uint8_t *p = spip->rxptr; + *p++ = ssp->DR; + spip->rxptr = p; + } + } + else + (void)ssp->DR; + if (--spip->rxcnt == 0) { + chDbgAssert(spip->txcnt == 0, + "spi_serve_interrupt(), #1", "counter out of synch"); + /* Stops the IRQ sources.*/ + 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->txcnt == 0) + ssp->IMSC = IMSC_ROR | IMSC_RT | IMSC_RX; +} + +/*===========================================================================*/ +/* Driver interrupt handlers. */ +/*===========================================================================*/ + +#if LPC_SPI_USE_SSP0 || defined(__DOXYGEN__) +/** + * @brief SSP0 interrupt handler. + * + * @isr + */ +CH_IRQ_HANDLER(Vector98) { + + CH_IRQ_PROLOGUE(); + + spi_serve_interrupt(&SPID1); + + CH_IRQ_EPILOGUE(); +} +#endif + +#if LPC_SPI_USE_SSP1 || defined(__DOXYGEN__) +/** + * @brief SSP1 interrupt handler. + * + * @isr + */ +CH_IRQ_HANDLER(Vector9C) { + + CH_IRQ_PROLOGUE(); + + spi_serve_interrupt(&SPID2); + + CH_IRQ_EPILOGUE(); +} +#endif + +/*===========================================================================*/ +/* Driver exported functions. */ +/*===========================================================================*/ + +/** + * @brief Low level SPI driver initialization. + * + * @notapi + */ +void spi_lld_init(void) { + +#if LPC_SPI_USE_SSP0 + spiObjectInit(&SPID1); + SPID1.ssp = LPC_SSP0; +#endif /* LPC_SPI_USE_SSP0 */ + +#if LPC_SPI_USE_SSP1 + spiObjectInit(&SPID2); + SPID2.ssp = LPC_SSP1; +#endif /* LPC_SPI_USE_SSP0 */ +} + +/** + * @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->state == SPI_STOP) { + /* Clock activation.*/ +#if LPC_SPI_USE_SSP0 + if (&SPID1 == spip) { + LPC_CCU2->CLK_APB0_SSP0_CFG = 1; + nvicEnableVector(SSP0_IRQn, + CORTEX_PRIORITY_MASK(LPC_SPI_SSP0_IRQ_PRIORITY)); + } +#endif +#if LPC_SPI_USE_SSP1 + if (&SPID2 == spip) { + LPC_CCU2->CLK_APB2_SSP1_CFG= 1; + nvicEnableVector(SSP1_IRQn, + CORTEX_PRIORITY_MASK(LPC_SPI_SSP1_IRQ_PRIORITY)); + } +#endif + } + /* Configuration.*/ + spip->ssp->CR1 = 0; + spip->ssp->ICR = ICR_RT | ICR_ROR; + spip->ssp->CR0 = spip->config->cr0; + spip->ssp->CPSR = spip->config->cpsr; + spip->ssp->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->state != SPI_STOP) { + spip->ssp->CR1 = 0; + spip->ssp->CR0 = 0; + spip->ssp->CPSR = 0; +#if LPC_SPI_USE_SSP0 + if (&SPID1 == spip) { + LPC_CCU2->CLK_APB0_SSP0_CFG = 0; + nvicDisableVector(SSP0_IRQn); + } +#endif +#if LPC_SPI_USE_SSP1 + if (&SPID2 == spip) { + LPC_CCU2->CLK_APB2_SSP1_CFG= 0; + nvicDisableVector(SSP1_IRQn); + } +#endif + } +} + +/** + * @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->config->ssport, spip->config->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->config->ssport, spip->config->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->rxptr = NULL; + spip->txptr = NULL; + spip->rxcnt = spip->txcnt = n; + ssp_fifo_preload(spip); + spip->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->rxptr = rxbuf; + spip->txptr = txbuf; + spip->rxcnt = spip->txcnt = n; + ssp_fifo_preload(spip); + spip->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->rxptr = NULL; + spip->txptr = txbuf; + spip->rxcnt = spip->txcnt = n; + ssp_fifo_preload(spip); + spip->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->rxptr = rxbuf; + spip->txptr = NULL; + spip->rxcnt = spip->txcnt = n; + ssp_fifo_preload(spip); + spip->ssp->IMSC = IMSC_ROR | IMSC_RT | IMSC_TX | IMSC_RX; +} + +/** + * @brief Exchanges one frame using a polled wait. + * @details This synchronous function exchanges one frame using a polled + * synchronization method. This function is useful when exchanging + * small amount of data on high speed channels, usually in this + * situation is much more efficient just wait for completion using + * polling than suspending the thread waiting for an interrupt. + * + * @param[in] spip pointer to the @p SPIDriver object + * @param[in] frame the data frame to send over the SPI bus + * @return The received data frame from the SPI bus. + */ +uint16_t spi_lld_polled_exchange(SPIDriver *spip, uint16_t frame) { + + spip->ssp->DR = (uint32_t)frame; + while ((spip->ssp->SR & SR_RNE) == 0) + ; + return (uint16_t)spip->ssp->DR; +} + +#endif /* HAL_USE_SPI */ + +/** @} */ |