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authorgdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4>2009-12-19 11:10:08 +0000
committergdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4>2009-12-19 11:10:08 +0000
commitc82d270d18cddcf15a0ccfcc95e861c33add8861 (patch)
tree446cccdcadf0db642f684dc3abd25e2c42e06abd /os/hal/platforms/LPC214x/spi_lld.c
parentcb565d0734615184aa74eb76981e55ff2aaebd35 (diff)
downloadChibiOS-c82d270d18cddcf15a0ccfcc95e861c33add8861.tar.gz
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LPC214x SPI driver added.
git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@1442 35acf78f-673a-0410-8e92-d51de3d6d3f4
Diffstat (limited to 'os/hal/platforms/LPC214x/spi_lld.c')
-rw-r--r--os/hal/platforms/LPC214x/spi_lld.c216
1 files changed, 216 insertions, 0 deletions
diff --git a/os/hal/platforms/LPC214x/spi_lld.c b/os/hal/platforms/LPC214x/spi_lld.c
new file mode 100644
index 000000000..f3f3e13b7
--- /dev/null
+++ b/os/hal/platforms/LPC214x/spi_lld.c
@@ -0,0 +1,216 @@
+/*
+ ChibiOS/RT - Copyright (C) 2006-2007 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 templates/spi_lld.c
+ * @brief SPI Driver subsystem low level driver source template.
+ * @addtogroup SPI_LLD
+ * @{
+ */
+
+#include "ch.h"
+#include "hal.h"
+
+#if CH_HAL_USE_SPI || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Low Level Driver exported variables. */
+/*===========================================================================*/
+
+#if USE_LPC214x_SPI1 || defined(__DOXYGEN__)
+/** @brief SPI1 driver identifier.*/
+SPIDriver SPID1;
+#endif
+
+/*===========================================================================*/
+/* Low Level Driver local variables. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Low Level Driver local functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Synchronous SSP 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) {
+
+ while (n > 0) {
+ if (SSPBase->SSP_SR & SR_RNE) {
+ uint8_t w = SSPBase->SSP_DR;
+ if (rxbuf != NULL)
+ *rxbuf++ = w;
+ n--;
+ continue; /* Priority over transmission. */
+ }
+ if (SSPBase->SSP_SR & SR_TNF) {
+ if (txbuf != NULL)
+ SSPBase->SSP_DR = *txbuf++;
+ else
+ SSPBase->SSP_DR = 0xFF;
+ }
+ }
+}
+
+/*===========================================================================*/
+/* Low Level Driver interrupt handlers. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Low Level Driver exported functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Low level SPI driver initialization.
+ */
+void spi_lld_init(void) {
+
+#if USE_LPC214x_SPI1
+ spiObjectInit(&SPID1);
+#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) {
+ /* Clock activation.*/
+ PCONP = (PCONP & PCALL) | PCSPI1;
+ }
+ /* Configuration.*/
+ SSPBase->SSP_CR1 = 0;
+ SSPBase->SSP_CR0 = spip->spd_config->spc_cr0;
+ SSPBase->SSP_CPSR = spip->spd_config->spc_cpsr;
+ SSPBase->SSP_CR1 = spip->spd_config->spc_cr1 | CR1_SSE;
+}
+
+/**
+ * @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) {
+ SSPBase->SSP_CR1 = 0;
+ SSPBase->SSP_CR0 = 0;
+ SSPBase->SSP_CPSR = 0;
+ PCONP &= ~PCSPI1;
+ }
+}
+
+/**
+ * @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 ever 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 */
+
+/** @} */