Merge branch 'master' of ../wifishield

2 files changed, 785 insertions, 0 deletions

diff --git a/firmwares/wifishield/wifiHD/src/SOFTWARE_FRAMEWORK/DRIVERS/SPI/spi.c b/firmwares/wifishield/wifiHD/src/SOFTWARE_FRAMEWORK/DRIVERS/SPI/spi.c
new file mode 100644
index 0000000..d2b7ccd
--- /dev/null
+++ b/firmwares/wifishield/wifiHD/src/SOFTWARE_FRAMEWORK/DRIVERS/SPI/spi.c
@@ -0,0 +1,443 @@
+/* This source file is part of the ATMEL AVR-UC3-SoftwareFramework-1.7.0 Release */
+
+/*This file is prepared for Doxygen automatic documentation generation.*/
+/*! \file *********************************************************************
+ *
+ * \brief SPI driver for AVR32 UC3.
+ *
+ * This file defines a useful set of functions for the SPI interface on AVR32
+ * devices.
+ *
+ * - Compiler:           IAR EWAVR32 and GNU GCC for AVR32
+ * - Supported devices:  All AVR32 devices with an SPI module can be used.
+ * - AppNote:
+ *
+ * \author               Atmel Corporation: http://www.atmel.com \n
+ *                       Support and FAQ: http://support.atmel.no/
+ *
+ ******************************************************************************/
+
+/* Copyright (c) 2009 Atmel Corporation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an Atmel
+ * AVR product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE
+ *
+ */
+
+#include "spi.h"
+
+#ifdef FREERTOS_USED
+
+#include "FreeRTOS.h"
+#include "semphr.h"
+
+#endif
+
+
+/*! \name SPI Writable Bit-Field Registers
+ */
+//! @{
+
+typedef union
+{
+  unsigned long                 cr;
+  avr32_spi_cr_t                CR;
+} u_avr32_spi_cr_t;
+
+typedef union
+{
+  unsigned long                 mr;
+  avr32_spi_mr_t                MR;
+} u_avr32_spi_mr_t;
+
+typedef union
+{
+  unsigned long                 tdr;
+  avr32_spi_tdr_t               TDR;
+} u_avr32_spi_tdr_t;
+
+typedef union
+{
+  unsigned long                 ier;
+  avr32_spi_ier_t               IER;
+} u_avr32_spi_ier_t;
+
+typedef union
+{
+  unsigned long                 idr;
+  avr32_spi_idr_t               IDR;
+} u_avr32_spi_idr_t;
+
+typedef union
+{
+  unsigned long                 csr;
+  avr32_spi_csr0_t              CSR;
+} u_avr32_spi_csr_t;
+
+//! @}
+
+
+#ifdef FREERTOS_USED
+
+//! The SPI mutex.
+static xSemaphoreHandle xSPIMutex;
+
+#endif
+
+
+/*! \brief Calculates the baudrate divider.
+ *
+ * \param options Pointer to a structure containing initialization options for
+ *                an SPI channel.
+ * \param pba_hz  SPI module input clock frequency (PBA clock, Hz).
+ *
+ * \return Divider or error code.
+ *   \retval >=0  Success.
+ *   \retval  <0  Error.
+ */
+static int getBaudDiv(const spi_options_t *options, unsigned int pba_hz)
+{
+  int baudDiv = (pba_hz + options->baudrate / 2) / options->baudrate;
+
+  if (baudDiv <= 0 || baudDiv > 255) {
+    return -1;
+  }
+
+  return baudDiv;
+}
+
+
+void spi_reset(volatile avr32_spi_t *spi)
+{
+  spi->cr = AVR32_SPI_CR_SWRST_MASK;
+}
+
+
+spi_status_t spi_initSlave(volatile avr32_spi_t *spi,
+                           unsigned char bits,
+                           unsigned char spi_mode)
+{
+  if (spi_mode > 3 ||
+      bits < 8 || bits > 16) {
+    return SPI_ERROR_ARGUMENT;
+  }
+
+  // Reset.
+  spi->cr = AVR32_SPI_CR_SWRST_MASK;
+
+  // Will use CSR0 offsets; these are the same for CSR0 to CSR3.
+  spi->csr0 = ((spi_mode >> 1) << AVR32_SPI_CSR0_CPOL_OFFSET) |
+              (((spi_mode & 0x1) ^ 0x1) << AVR32_SPI_CSR0_NCPHA_OFFSET) |
+              ((bits - 8) << AVR32_SPI_CSR0_BITS_OFFSET);
+
+  return SPI_OK;
+}
+
+
+spi_status_t spi_initTest(volatile avr32_spi_t *spi)
+{
+  // Reset.
+  spi->cr = AVR32_SPI_CR_SWRST_MASK;
+  spi->mr |= AVR32_SPI_MR_MSTR_MASK | // Master Mode.
+             AVR32_SPI_MR_LLB_MASK;   // Local Loopback.
+
+  return SPI_OK;
+}
+
+
+spi_status_t spi_initMaster(volatile avr32_spi_t *spi, const spi_options_t *options)
+{
+  u_avr32_spi_mr_t u_avr32_spi_mr;
+
+  if (options->modfdis > 1) {
+    return SPI_ERROR_ARGUMENT;
+  }
+
+  // Reset.
+  spi->cr = AVR32_SPI_CR_SWRST_MASK;
+
+  // Master Mode.
+  u_avr32_spi_mr.mr = spi->mr;
+  u_avr32_spi_mr.MR.mstr = 1;
+  u_avr32_spi_mr.MR.modfdis = options->modfdis;
+  u_avr32_spi_mr.MR.llb = 0;
+  u_avr32_spi_mr.MR.pcs = (1 << AVR32_SPI_MR_PCS_SIZE) - 1;
+  spi->mr = u_avr32_spi_mr.mr;
+
+  return SPI_OK;
+}
+
+
+spi_status_t spi_selectionMode(volatile avr32_spi_t *spi,
+                               unsigned char variable_ps,
+                               unsigned char pcs_decode,
+                               unsigned char delay)
+{
+  u_avr32_spi_mr_t u_avr32_spi_mr;
+
+  if (variable_ps > 1 ||
+      pcs_decode > 1) {
+    return SPI_ERROR_ARGUMENT;
+  }
+
+  u_avr32_spi_mr.mr = spi->mr;
+  u_avr32_spi_mr.MR.ps = variable_ps;
+  u_avr32_spi_mr.MR.pcsdec = pcs_decode;
+  u_avr32_spi_mr.MR.dlybcs = delay;
+  spi->mr = u_avr32_spi_mr.mr;
+
+  return SPI_OK;
+}
+
+
+spi_status_t spi_selectChip(volatile avr32_spi_t *spi, unsigned char chip)
+{
+#ifdef FREERTOS_USED
+  while (pdFALSE == xSemaphoreTake(xSPIMutex, 20));
+#endif
+
+  // Assert all lines; no peripheral is selected.
+  spi->mr |= AVR32_SPI_MR_PCS_MASK;
+
+  if (spi->mr & AVR32_SPI_MR_PCSDEC_MASK) {
+    // The signal is decoded; allow up to 15 chips.
+    if (chip > 14) {
+      return SPI_ERROR_ARGUMENT;
+    }
+
+    spi->mr &= ~AVR32_SPI_MR_PCS_MASK | (chip << AVR32_SPI_MR_PCS_OFFSET);
+  } else {
+    if (chip > 3) {
+      return SPI_ERROR_ARGUMENT;
+    }
+
+    spi->mr &= ~(1 << (AVR32_SPI_MR_PCS_OFFSET + chip));
+  }
+
+  return SPI_OK;
+}
+
+
+spi_status_t spi_unselectChip(volatile avr32_spi_t *spi, unsigned char chip)
+{
+  unsigned int timeout = SPI_TIMEOUT;
+
+  while (!(spi->sr & AVR32_SPI_SR_TXEMPTY_MASK)) {
+    if (!timeout--) {
+      return SPI_ERROR_TIMEOUT;
+    }
+  }
+
+  // Assert all lines; no peripheral is selected.
+  spi->mr |= AVR32_SPI_MR_PCS_MASK;
+
+  // Last transfer, so deassert the current NPCS if CSAAT is set.
+  spi->cr = AVR32_SPI_CR_LASTXFER_MASK;
+
+#ifdef FREERTOS_USED
+  xSemaphoreGive(xSPIMutex);
+#endif
+
+  return SPI_OK;
+}
+
+
+spi_status_t spi_setupChipReg(volatile avr32_spi_t *spi,
+                              const spi_options_t *options,
+                              unsigned int pba_hz)
+{
+  u_avr32_spi_csr_t u_avr32_spi_csr;
+
+  if (options->spi_mode > 3 ||
+      options->stay_act > 1 ||
+      options->bits < 8 || options->bits > 16) {
+    return SPI_ERROR_ARGUMENT;
+  }
+
+  int baudDiv = getBaudDiv(options, pba_hz);
+
+  if (baudDiv < 0) {
+    return SPI_ERROR_ARGUMENT;
+  }
+
+  // Will use CSR0 offsets; these are the same for CSR0 to CSR3.
+  u_avr32_spi_csr.csr = 0;
+  u_avr32_spi_csr.CSR.cpol = options->spi_mode >> 1;
+  u_avr32_spi_csr.CSR.ncpha = (options->spi_mode & 0x1) ^ 0x1;
+  u_avr32_spi_csr.CSR.csaat = options->stay_act;
+  u_avr32_spi_csr.CSR.bits = options->bits - 8;
+  u_avr32_spi_csr.CSR.scbr = baudDiv;
+  u_avr32_spi_csr.CSR.dlybs = options->spck_delay;
+  u_avr32_spi_csr.CSR.dlybct = options->trans_delay;
+
+  switch(options->reg) {
+    case 0:
+      spi->csr0 = u_avr32_spi_csr.csr;
+      break;
+    case 1:
+      spi->csr1 = u_avr32_spi_csr.csr;
+      break;
+    case 2:
+      spi->csr2 = u_avr32_spi_csr.csr;
+      break;
+    case 3:
+      spi->csr3 = u_avr32_spi_csr.csr;
+      break;
+    default:
+      return SPI_ERROR_ARGUMENT;
+  }
+
+#ifdef FREERTOS_USED
+  if (!xSPIMutex)
+  {
+    // Create the SPI mutex.
+    vSemaphoreCreateBinary(xSPIMutex);
+    if (!xSPIMutex)
+    {
+      while(1);
+    }
+  }
+#endif
+
+  return SPI_OK;
+}
+
+
+void spi_enable(volatile avr32_spi_t *spi)
+{
+  spi->cr = AVR32_SPI_CR_SPIEN_MASK;
+}
+
+
+void spi_disable(volatile avr32_spi_t *spi)
+{
+  spi->cr = AVR32_SPI_CR_SPIDIS_MASK;
+}
+
+
+int spi_is_enabled(volatile avr32_spi_t *spi)
+{
+  return (spi->sr & AVR32_SPI_SR_SPIENS_MASK) != 0;
+}
+
+
+inline unsigned char spi_writeRegisterEmptyCheck(volatile avr32_spi_t *spi)
+{
+  return ((spi->sr & AVR32_SPI_SR_TDRE_MASK) != 0);
+}
+
+
+inline spi_status_t spi_write(volatile avr32_spi_t *spi, unsigned short data)
+{
+  unsigned int timeout = SPI_TIMEOUT;
+
+  while (!(spi->sr & AVR32_SPI_SR_TDRE_MASK)) {
+    if (!timeout--) {
+      return SPI_ERROR_TIMEOUT;
+    }
+  }
+
+  spi->tdr = data << AVR32_SPI_TDR_TD_OFFSET;
+
+  return SPI_OK;
+}
+
+
+spi_status_t spi_variableSlaveWrite(volatile avr32_spi_t *spi, unsigned short data,
+                                    unsigned char pcs, unsigned char lastxfer)
+{
+  unsigned int timeout = SPI_TIMEOUT;
+
+  if (pcs > 14 || lastxfer > 1) {
+    return SPI_ERROR_ARGUMENT;
+  }
+
+  while (!(spi->sr & AVR32_SPI_SR_TDRE_MASK)) {
+    if (!timeout--) {
+      return SPI_ERROR_TIMEOUT;
+    }
+  }
+
+  spi->tdr = (data << AVR32_SPI_TDR_TD_OFFSET) |
+             (pcs << AVR32_SPI_TDR_PCS_OFFSET) |
+             (lastxfer << AVR32_SPI_TDR_LASTXFER_OFFSET);
+
+  return SPI_OK;
+}
+
+
+inline unsigned char spi_writeEndCheck(volatile avr32_spi_t *spi)
+{
+  return ((spi->sr & AVR32_SPI_SR_TXEMPTY_MASK) != 0);
+}
+
+
+unsigned char spi_readRegisterFullCheck(volatile avr32_spi_t *spi)
+{
+  return ((spi->sr & AVR32_SPI_SR_RDRF_MASK) != 0);
+}
+
+
+inline spi_status_t spi_read(volatile avr32_spi_t *spi, unsigned short *data)
+{
+  unsigned int timeout = SPI_TIMEOUT;
+
+  while ((spi->sr & (AVR32_SPI_SR_RDRF_MASK | AVR32_SPI_SR_TXEMPTY_MASK)) !=
+         (AVR32_SPI_SR_RDRF_MASK | AVR32_SPI_SR_TXEMPTY_MASK)) {
+    if (!timeout--) {
+      return SPI_ERROR_TIMEOUT;
+    }
+  }
+
+  *data = spi->rdr >> AVR32_SPI_RDR_RD_OFFSET;
+
+  return SPI_OK;
+}
+
+
+unsigned char spi_getStatus(volatile avr32_spi_t *spi)
+{
+  spi_status_t ret = SPI_OK;
+  unsigned long sr = spi->sr;
+
+  if (sr & AVR32_SPI_SR_OVRES_MASK) {
+    ret = SPI_ERROR_OVERRUN;
+  }
+
+  if (sr & AVR32_SPI_SR_MODF_MASK) {
+    ret += SPI_ERROR_MODE_FAULT;
+  }
+
+  if (ret == (SPI_ERROR_OVERRUN + SPI_ERROR_MODE_FAULT)) {
+    return SPI_ERROR_OVERRUN_AND_MODE_FAULT;
+  }
+  else if (ret > 0) {
+    return ret;
+  } else {
+    return SPI_OK;
+  }
+}
diff --git a/firmwares/wifishield/wifiHD/src/SOFTWARE_FRAMEWORK/DRIVERS/SPI/spi.h b/firmwares/wifishield/wifiHD/src/SOFTWARE_FRAMEWORK/DRIVERS/SPI/spi.h
new file mode 100644
index 0000000..6dcc928
--- /dev/null
+++ b/firmwares/wifishield/wifiHD/src/SOFTWARE_FRAMEWORK/DRIVERS/SPI/spi.h
@@ -0,0 +1,342 @@
+/* This header file is part of the ATMEL AVR-UC3-SoftwareFramework-1.7.0 Release */
+
+/*This file is prepared for Doxygen automatic documentation generation.*/
+/*! \file *********************************************************************
+ *
+ * \brief SPI driver for AVR32 UC3.
+ *
+ * This file defines a useful set of functions for the SPI interface on AVR32
+ * devices.
+ *
+ * - Compiler:           IAR EWAVR32 and GNU GCC for AVR32
+ * - Supported devices:  All AVR32 devices with an SPI module can be used.
+ * - AppNote:
+ *
+ * \author               Atmel Corporation: http://www.atmel.com \n
+ *                       Support and FAQ: http://support.atmel.no/
+ *
+ ******************************************************************************/
+
+/* Copyright (c) 2009 Atmel Corporation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an Atmel
+ * AVR product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE
+ *
+ */
+
+#ifndef _SPI_H_
+#define _SPI_H_
+
+#include <avr32/io.h>
+
+
+//! Time-out value (number of attempts).
+#define SPI_TIMEOUT       10000
+
+
+//! Status codes used by the SPI driver.
+typedef enum
+{
+  SPI_ERROR = -1,
+  SPI_OK = 0,
+  SPI_ERROR_TIMEOUT = 1,
+  SPI_ERROR_ARGUMENT,
+  SPI_ERROR_OVERRUN,
+  SPI_ERROR_MODE_FAULT,
+  SPI_ERROR_OVERRUN_AND_MODE_FAULT
+} spi_status_t;
+
+//! Option structure for SPI channels.
+typedef struct
+{
+  //! The SPI channel to set up.
+  unsigned char reg;
+
+  //! Preferred baudrate for the SPI.
+  unsigned int baudrate;
+
+  //! Number of bits in each character (8 to 16).
+  unsigned char bits;
+
+  //! Delay before first clock pulse after selecting slave (in PBA clock periods).
+  unsigned char spck_delay;
+
+  //! Delay between each transfer/character (in PBA clock periods).
+  unsigned char trans_delay;
+
+  //! Sets this chip to stay active after last transfer to it.
+  unsigned char stay_act;
+
+  //! Which SPI mode to use when transmitting.
+  unsigned char spi_mode;
+
+  //! Disables the mode fault detection.
+  //! With this bit cleared, the SPI master mode will disable itself if another
+  //! master tries to address it.
+  unsigned char modfdis;
+} spi_options_t;
+
+
+/*! \brief Resets the SPI controller.
+ *
+ * \param spi Base address of the SPI instance.
+ */
+extern void spi_reset(volatile avr32_spi_t *spi);
+
+/*! \brief Initializes the SPI in slave mode.
+ *
+ * \param spi       Base address of the SPI instance.
+ * \param bits      Number of bits in each transmitted character (8 to 16).
+ * \param spi_mode  Clock polarity and phase.
+ *
+ * \return Status.
+ *   \retval SPI_OK             Success.
+ *   \retval SPI_ERROR_ARGUMENT Invalid argument(s) passed.
+ */
+extern spi_status_t spi_initSlave(volatile avr32_spi_t *spi,
+                                  unsigned char bits,
+                                  unsigned char spi_mode);
+
+/*! \brief Sets up the SPI in a test mode where the transmitter is connected to
+ *         the receiver (local loopback).
+ *
+ * \param spi Base address of the SPI instance.
+ *
+ * \return Status.
+ *   \retval SPI_OK Success.
+ */
+extern spi_status_t spi_initTest(volatile avr32_spi_t *spi);
+
+/*! \brief Initializes the SPI in master mode.
+ *
+ * \param spi     Base address of the SPI instance.
+ * \param options Pointer to a structure containing initialization options.
+ *
+ * \return Status.
+ *   \retval SPI_OK             Success.
+ *   \retval SPI_ERROR_ARGUMENT Invalid argument(s) passed.
+ */
+extern spi_status_t spi_initMaster(volatile avr32_spi_t *spi, const spi_options_t *options);
+
+/*! \brief Sets up how and when the slave chips are selected (master mode only).
+ *
+ * \param spi         Base address of the SPI instance.
+ * \param variable_ps Target slave is selected in transfer register for every
+ *                    character to transmit.
+ * \param pcs_decode  The four chip select lines are decoded externally. Values
+ *                    0 to 14 can be given to \ref spi_selectChip.
+ * \param delay       Delay in PBA periods between chip selects.
+ *
+ * \return Status.
+ *   \retval SPI_OK             Success.
+ *   \retval SPI_ERROR_ARGUMENT Invalid argument(s) passed.
+ */
+extern spi_status_t spi_selectionMode(volatile avr32_spi_t *spi,
+                                      unsigned char variable_ps,
+                                      unsigned char pcs_decode,
+                                      unsigned char delay);
+
+/*! \brief Selects slave chip.
+ *
+ * \param spi   Base address of the SPI instance.
+ * \param chip  Slave chip number (normal: 0 to 3, extarnally decoded signal: 0
+ *              to 14).
+ *
+ * \return Status.
+ *   \retval SPI_OK             Success.
+ *   \retval SPI_ERROR_ARGUMENT Invalid argument(s) passed.
+ */
+extern spi_status_t spi_selectChip(volatile avr32_spi_t *spi, unsigned char chip);
+
+/*! \brief Unselects slave chip.
+ *
+ * \param spi   Base address of the SPI instance.
+ * \param chip  Slave chip number (normal: 0 to 3, extarnally decoded signal: 0
+ *              to 14).
+ *
+ * \return Status.
+ *   \retval SPI_OK             Success.
+ *   \retval SPI_ERROR_TIMEOUT  Time-out.
+ *
+ * \note Will block program execution until time-out occurs if last transmission
+ *       is not complete. Invoke \ref spi_writeEndCheck beforehand if needed.
+ */
+extern spi_status_t spi_unselectChip(volatile avr32_spi_t *spi, unsigned char chip);
+
+/*! \brief Sets options for a specific slave chip.
+ *
+ * The baudrate field has to be written before transfer in master mode. Four
+ * similar registers exist, one for each slave. When using encoded slave
+ * addressing, reg=0 sets options for slaves 0 to 3, reg=1 for slaves 4 to 7 and
+ * so on.
+ *
+ * \param spi     Base address of the SPI instance.
+ * \param options Pointer to a structure containing initialization options for
+ *                an SPI channel.
+ * \param pba_hz  SPI module input clock frequency (PBA clock, Hz).
+ *
+ * \return Status.
+ *   \retval SPI_OK             Success.
+ *   \retval SPI_ERROR_ARGUMENT Invalid argument(s) passed.
+ */
+extern spi_status_t spi_setupChipReg(volatile avr32_spi_t *spi,
+                                     const spi_options_t *options,
+                                     unsigned int pba_hz);
+
+/*! \brief Enables the SPI.
+ *
+ * \param spi Base address of the SPI instance.
+ */
+extern void spi_enable(volatile avr32_spi_t *spi);
+
+/*! \brief Disables the SPI.
+ *
+ * Ensures that nothing is transferred while setting up buffers.
+ *
+ * \param spi Base address of the SPI instance.
+ *
+ * \warning This may cause data loss if used on a slave SPI.
+ */
+extern void spi_disable(volatile avr32_spi_t *spi);
+
+/*! \brief Tests if the SPI is enabled.
+ *
+ * \param spi Base address of the SPI instance.
+ *
+ * \return \c 1 if the SPI is enabled, otherwise \c 0.
+ */
+extern int spi_is_enabled(volatile avr32_spi_t *spi);
+
+/*! \brief Checks if there is no data in the transmit register.
+ *
+ * \param spi Base address of the SPI instance.
+ *
+ * \return Status.
+ *   \retval 1  No data in TDR.
+ *   \retval 0  Some data in TDR.
+ */
+extern unsigned char spi_writeRegisterEmptyCheck(volatile avr32_spi_t *spi);
+
+/*! \brief Writes one data word in master fixed peripheral select mode or in
+ *         slave mode.
+ *
+ * \param spi   Base address of the SPI instance.
+ * \param data  The data word to write.
+ *
+ * \return Status.
+ *   \retval SPI_OK             Success.
+ *   \retval SPI_ERROR_TIMEOUT  Time-out.
+ *
+ * \note Will block program execution until time-out occurs if transmitter is
+ *       busy and transmit buffer is full. Invoke
+ *       \ref spi_writeRegisterEmptyCheck beforehand if needed.
+ *
+ * \note Once the data has been written to the transmit buffer, the end of
+ *       transmission is not waited for. Invoke \ref spi_writeEndCheck if
+ *       needed.
+ */
+extern spi_status_t spi_write(volatile avr32_spi_t *spi, unsigned short data);
+
+/*! \brief Selects a slave in master variable peripheral select mode and writes
+ *         one data word to it.
+ *
+ * \param spi       Base address of the SPI instance.
+ * \param data      The data word to write.
+ * \param pcs       Slave selector (bit 0 -> nCS line 0, bit 1 -> nCS line 1,
+ *                  etc.).
+ * \param lastxfer  Boolean indicating whether this is the last data word
+ *                  transfer.
+ *
+ * \return Status.
+ *   \retval SPI_OK             Success.
+ *   \retval SPI_ERROR_TIMEOUT  Time-out.
+ *   \retval SPI_ERROR_ARGUMENT Invalid argument(s) passed.
+ *
+ * \note Will block program execution until time-out occurs if transmitter is
+ *       busy and transmit buffer is full. Invoke
+ *       \ref spi_writeRegisterEmptyCheck beforehand if needed.
+ *
+ * \note Once the data has been written to the transmit buffer, the end of
+ *       transmission is not waited for. Invoke \ref spi_writeEndCheck if
+ *       needed.
+ */
+extern spi_status_t spi_variableSlaveWrite(volatile avr32_spi_t *spi,
+                                           unsigned short data,
+                                           unsigned char pcs,
+                                           unsigned char lastxfer);
+
+/*! \brief Checks if all transmissions are complete.
+ *
+ * \param spi Base address of the SPI instance.
+ *
+ * \return Status.
+ *   \retval 1  All transmissions complete.
+ *   \retval 0  Transmissions not complete.
+ */
+extern unsigned char spi_writeEndCheck(volatile avr32_spi_t *spi);
+
+/*! \brief Checks if there is data in the receive register.
+ *
+ * \param spi Base address of the SPI instance.
+ *
+ * \return Status.
+ *   \retval 1  Some data in RDR.
+ *   \retval 0  No data in RDR.
+ */
+extern unsigned char spi_readRegisterFullCheck(volatile avr32_spi_t *spi);
+
+/*! \brief Reads one data word in master mode or in slave mode.
+ *
+ * \param spi   Base address of the SPI instance.
+ * \param data  Pointer to the location where to store the received data word.
+ *
+ * \return Status.
+ *   \retval SPI_OK             Success.
+ *   \retval SPI_ERROR_TIMEOUT  Time-out.
+ *
+ * \note Will block program execution until time-out occurs if no data is
+ *       received or last transmission is not complete. Invoke
+ *       \ref spi_writeEndCheck or \ref spi_readRegisterFullCheck beforehand if
+ *       needed.
+ */
+extern spi_status_t spi_read(volatile avr32_spi_t *spi, unsigned short *data);
+
+/*! \brief Gets status information from the SPI.
+ *
+ * \param spi Base address of the SPI instance.
+ *
+ * \return Status.
+ *   \retval SPI_OK                           Success.
+ *   \retval SPI_ERROR_OVERRUN                Overrun error.
+ *   \retval SPI_ERROR_MODE_FAULT             Mode fault (SPI addressed as slave
+ *                                            while in master mode).
+ *   \retval SPI_ERROR_OVERRUN_AND_MODE_FAULT Overrun error and mode fault.
+ */
+extern unsigned char spi_getStatus(volatile avr32_spi_t *spi);
+
+
+#endif  // _SPI_H_