nuttx/arch/arm/src/sam34/sam_spi.h

/************************************************************************************
 * arch/arm/src/sam34/sam_spi.h
 *
 *   Copyright (C) 2009-2011, 2013 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.
 *
 ************************************************************************************/

#ifndef __ARCH_ARM_SRC_SAM34_SAM_SPI_H
#define __ARCH_ARM_SRC_SAM34_SAM_SPI_H

/************************************************************************************
 * Included Files
 ************************************************************************************/

#include <nuttx/config.h>

#include <stdint.h>
#include <stdbool.h>

#include "chip.h"

/************************************************************************************
 * Definitions
 ************************************************************************************/

/************************************************************************************
 * Public Types
 ************************************************************************************/

/************************************************************************************
 * Inline Functions
 ************************************************************************************/

#ifndef __ASSEMBLY__

/************************************************************************************
 * Public Data
 ************************************************************************************/

#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif

/************************************************************************************
 * Public Function Prototypes
 ************************************************************************************/

/****************************************************************************
 * Name:  sam_spiselect, sam_spistatus, and sam_spicmddata
 *
 * Description:
 *   These external functions must be provided by board-specific logic.  They
 *   include:
 *
 *   o sam_spiselect is a functions tomanage the board-specific chip selects
 *   o sam_spistatus and sam_spicmddata:  Implementations of the status
 *     and cmddata methods of the SPI interface defined by struct spi_ops_
 *     (see include/nuttx/spi/spi.h). All other methods including
 *     up_spiinitialize()) are provided by common SAM3/4 logic.
 *
 *  To use this common SPI logic on your board:
 *
 *   1. Provide logic in sam_boardinitialize() to configure SPI chip select
 *      pins.
 *   2. Provide sam_spiselect() and sam_spistatus() functions in your board-
 *      specific logic.  These functions will perform chip selection and
 *      status operations using GPIOs in the way your board is configured.
 *   2. If CONFIG_SPI_CMDDATA is defined in the NuttX configuration, provide
 *      sam_spicmddata() functions in your board-specific logic.  This
 *      function will perform cmd/data selection operations using GPIOs in
 *      the way your board is configured.
 *   3. Add a call to up_spiinitialize() in your low level application
 *      initialization logic
 *   4. The handle returned by up_spiinitialize() 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).
 *
 ****************************************************************************/

#ifdef CONFIG_SAM34_SPI0
struct spi_dev_s;
enum spi_dev_e;

/****************************************************************************
 * Name: sam_spiselect
 *
 * Description:
 *   PIO chip select pins may be programmed by the board specific logic in
 *   one of two different ways.  First, the pins may be programmed as SPI
 *   peripherals.  In that case, the pins are completely controlled by the
 *   SPI driver.  This method still needs to be provided, but it may be only
 *   a stub.
 *
 *   An alternative way to program the PIO chip select pins is as a normal
 *   GPIO output.  In that case, the automatic control of the CS pins is
 *   bypassed and this function must provide control of the chip select.
 *   NOTE:  In this case, the GPIO output pin does *not* have to be the
 *   same as the NPCS pin normal associated with the chip select number.
 *
 * Input Parameters:
 *   dev - SPI device info
 *   devid - Identifies the (logical) device
 *   selected - TRUE:Select the device, FALSE:De-select the device
 *
 * Returned Values:
 *   None
 *
 ****************************************************************************/

void sam_spiselect(enum spi_dev_e devid, bool selected);

/****************************************************************************
 * Name: sam_spistatus
 *
 * Description:
 *   Return status information associated with the SPI device.
 *
 * Input Parameters:
 *   dev - SPI device info
 *   devid - Identifies the (logical) device
 *
 * Returned Values:
 *   Bit-encoded SPI status (see include/nuttx/spi/spi.h.
 *
 ****************************************************************************/

uint8_t sam_spistatus(FAR struct spi_dev_s *dev, enum spi_dev_e devid);

/****************************************************************************
 * Name: sam_spicmddata
 *
 * Description:
 *   Some SPI devices require an additional control to determine if the SPI
 *   data being sent is a command or is data.  If CONFIG_SPI_CMDDATA then
 *   this function will be called to different be command and data transfers.
 *
 *   This is often needed, for example, by LCD drivers.  Some LCD hardware
 *   may be configured to use 9-bit data transfers with the 9th bit
 *   indicating command or data.  That same hardware may be configurable,
 *   instead, to use 8-bit data but to require an additional, board-
 *   specific GPIO control to distinguish command and data.  This function
 *   would be needed in that latter case.
 *
 * Input Parameters:
 *   dev - SPI device info
 *   devid - Identifies the (logical) device
 *
 * Returned Values:
 *   Zero on success; a negated errno on failure.
 *
 ****************************************************************************/

#ifdef CONFIG_SPI_CMDDATA
int sam_spicmddata(FAR struct spi_dev_s *dev, enum spi_dev_e devid, bool cmd);
#endif
#endif /* CONFIG_SAM34_SPI0 */

#undef EXTERN
#if defined(__cplusplus)
}
#endif

#endif /* __ASSEMBLY__ */
#endif /* __ARCH_ARM_SRC_SAM34_SAM_SPI_H */