text: /****************************************************************************
   * boards/arm/tiva/lm3s6432-s2e/src/lm_ssi.c
   *
   *   Copyright (C) 2010 Gregory Nutt. All rights reserved.
   *   Author: Gregory Nutt <gnutt@nuttx.org>
   *
   * 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. Neither the name NuttX nor the names of its contributors may be
   *    used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   * COPYRIGHT OWNER OR CONTRIBUTORS 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.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <stdint.h>
  #include <stdbool.h>
  #include <debug.h>
  
  #include <nuttx/spi/spi.h>
  #include <arch/board/board.h>
  
  #include "arm_arch.h"
  #include "chip.h"
  #include "tiva_gpio.h"
  #include "lm3s6432-s2e.h"
  
  #if defined(CONFIG_TIVA_SSI0)
  
  /****************************************************************************
   * Pre-processor Definitions
   ****************************************************************************/
  
  /* CONFIG_DEBUG_SPI enables debug output from this file */
  
  #ifdef CONFIG_DEBUG_SPI
  #  define ssi_dumpgpio(m) tiva_dumpgpio(SDCCS_GPIO, m)
  #else
  #  define ssi_dumpgpio(m)
  #endif
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: lm_ssidev_initialize
   *
   * Description:
   *   Called to configure SPI chip select GPIO pins for the MDL-S2E.
   *
   ****************************************************************************/
  
  void weak_function lm_ssidev_initialize(void)
  {
    /* Configure the SPI CS GPIO */
  
    ssi_dumpgpio("lm_ssidev_initialize() Entry)");
    tiva_configgpio(SSICS_GPIO);
    ssi_dumpgpio("lm_ssidev_initialize() Exit");
  }
  
  /****************************************************************************
   * The external functions, tiva_ssiselect and tiva_ssistatus must be provided
   * by board-specific logic.  The are implementations of the select and status
   * methods SPI interface defined by struct spi_ops_s
   * (see include/nuttx/spi/spi.h).
   * All othermethods (including tiva_ssibus_initialize()) are provided by
   * common logic.
   * To use this common SPI logic on your board:
   *
   *   1. Provide tiva_ssiselect() and tiva_ssistatus() functions in your
   *      board-specific logic.  This function will perform chip selection and
   *      status operations using GPIOs in the way your board is configured.
   *   2. Add a call to tiva_ssibus_initialize() in your low level
   *      initialization logic
   *   3. The handle returned by tiva_ssibus_initialize() may then be used to
   *      bind the SPI driver to higher level logic (e.g., calling
   *      mmcsd_spislotinitialize(), for example, will bind the SPI driver to
   *      the SPI MMC/SD driver).
   *
   ****************************************************************************/
  
  void tiva_ssiselect(FAR struct spi_dev_s *dev, uint32_t devid, bool selected)
  {
    spiinfo("devid: %d CS: %s\n", (int)devid,
            selected ? "assert" : "de-assert");
    ssi_dumpgpio("tiva_ssiselect() Entry");
  
    if (devid == SPIDEV_MMCSD(0))
      {
        /* Assert the CS pin to the card */
  
        tiva_gpiowrite(SDCCS_GPIO, !selected);
      }
  
    ssi_dumpgpio("tiva_ssiselect() Exit");
  }
  
  uint8_t tiva_ssistatus(FAR struct spi_dev_s *dev, uint32_t devid)
  {
    spiinfo("Returning SPI_STATUS_PRESENT\n");
    return SPI_STATUS_PRESENT;
  }
  
  #endif /* CONFIG_TIVA_SSI0 */
  