nuttx/arch/arm/src/sam3u/sam3u_pio.c

/****************************************************************************
 * arch/arm/src/sam3u/sam3u_pio.c
 *
 *   Copyright (C) 2010 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
 *
 * 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 <time.h>
#include <errno.h>
#include <debug.h>

#include <nuttx/arch.h>
#include <arch/board/board.h>

#include "up_internal.h"
#include "up_arch.h"

#include "chip.h"
#include "sam3u_internal.h"
#include "sam3u_pio.h"

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

/****************************************************************************
 * Private Types
 ****************************************************************************/

/****************************************************************************
 * Private Data
 ****************************************************************************/

/****************************************************************************
 * Private Function Prototypes
 ****************************************************************************/
/****************************************************************************
 * Name: sam3u_gpiobase
 *
 * Description:
 *   Return the base address of the GPIO register set
 *
 ****************************************************************************/

static inline uintptr_t sam3u_gpiobase(uint16_t cfgset)
{
  int port = (cfgset & GPIO_PORT_MASK) >> GPIO_PORT_SHIFT;
  return SAM3U_PION_BASE(port);
}

/****************************************************************************
 * Name: sam3u_gpiopin
 *
 * Description:
 *   Returun the base address of the GPIO register set
 *
 ****************************************************************************/

static inline int sam3u_gpiopin(uint16_t cfgset)
{
  return 1 << ((cfgset & GPIO_PIN_MASK) >> GPIO_PIN_SHIFT);
}

/****************************************************************************
 * Name: sam3u_configinput
 *
 * Description:
 *   Configure a GPIO input pin based on bit-encoded description of the pin.
 *
 ****************************************************************************/

static inline int sam3u_configinput(uintptr_t base, uint32_t pin,
                                    uint16_t cfgset)
{
  /* Disable interrupts on the pin */

  putreg32(pin, base+SAM3U_PIO_IDR_OFFSET);

  /* Enable/disable the pull-up as requested */

  if ((cfgset & GPIO_CFG_PULLUP) != 0)
    {
      putreg32(pin, base+SAM3U_PIO_PUER_OFFSET);
    }
  else
    {
      putreg32(pin, base+SAM3U_PIO_PUDR_OFFSET);
    }

  /* Check if filtering should be enabled */

  if ((cfgset & GPIO_CFG_DEGLITCH) != 0)
    {
      putreg32(pin, base+SAM3U_PIO_IFER_OFFSET);
    }
  else
    {
      putreg32(pin, base+SAM3U_PIO_IFDR_OFFSET);
    }

  /* Configure the pin as an input and enable the GPIO function */

  putreg32(pin, base+SAM3U_PIO_ODR_OFFSET);
  putreg32(pin, base+SAM3U_PIO_PER_OFFSET);

  /* To-Do:  If DEGLITCH is selected, need to configure DIFSR, SCIFSR, and
   *         registers.  This would probably best be done with another, new
   *         API... perhaps sam3u_configfilter()
   */

 return OK;
}

/****************************************************************************
 * Name: sam3u_configoutput
 *
 * Description:
 *   Configure a GPIO output pin based on bit-encoded description of the pin.
 *
 ****************************************************************************/

static inline int sam3u_configoutput(uintptr_t base, uint32_t pin,
                                     uint16_t cfgset)
{
  /* Disable interrupts on the pin */

  putreg32(pin, base+SAM3U_PIO_IDR_OFFSET);

  /* Enable/disable the pull-up as requested */

  if ((cfgset & GPIO_CFG_PULLUP) != 0)
    {
      putreg32(pin, base+SAM3U_PIO_PUER_OFFSET);
    }
  else
    {
      putreg32(pin, base+SAM3U_PIO_PUDR_OFFSET);
    }

  /* Enable the open drain driver if requrested */

  if ((cfgset & GPIO_CFG_OPENDRAIN) != 0)
    {
      putreg32(pin, base+SAM3U_PIO_MDER_OFFSET);
    }
  else
    {
      putreg32(pin, base+SAM3U_PIO_MDDR_OFFSET);
    }

  /* Set default value */

  if ((cfgset & GPIO_OUTPUT_SET) != 0)
    {
      putreg32(pin, base+SAM3U_PIO_SODR_OFFSET);
    }
  else
    {
      putreg32(pin, base+SAM3U_PIO_CODR_OFFSET);
    }

  /* Configure the pin as an input and enable the GPIO function */

  putreg32(pin, base+SAM3U_PIO_OER_OFFSET);
  putreg32(pin, base+SAM3U_PIO_PER_OFFSET);
  return OK;
}

/****************************************************************************
 * Name: sam3u_configperiph
 *
 * Description:
 *   Configure a GPIO pin driven by a peripheral A or B signal based on
 *   bit-encoded description of the pin.
 *
 ****************************************************************************/

static inline int sam3u_configperiph(uintptr_t base, uint32_t pin,
                                     uint16_t cfgset)
{
  uint32_t regval;

  /* Disable interrupts on the pin */

  putreg32(pin, base+SAM3U_PIO_IDR_OFFSET);

  /* Enable/disable the pull-up as requested */

  if ((cfgset & GPIO_CFG_PULLUP) != 0)
    {
      putreg32(pin, base+SAM3U_PIO_PUER_OFFSET);
    }
  else
    {
      putreg32(pin, base+SAM3U_PIO_PUDR_OFFSET);
    }

  /* Configure pin, depending upon the peripheral A or B*/

  regval = getreg32(base+SAM3U_PIO_ABSR_OFFSET);
  if ((cfgset & GPIO_MODE_MASK) == GPIO_PERIPHA)
    {
      regval &= ~pin;
    }
  else
    {
      regval |= pin;
    }
  putreg32(regval, base+SAM3U_PIO_ABSR_OFFSET);

  /* Disable PIO functionality */

  putreg32(pin, base+SAM3U_PIO_PDR_OFFSET);
  return OK;
}

/****************************************************************************
 * Global Functions
 ****************************************************************************/

/****************************************************************************
 * Name: sam3u_configgpio
 *
 * Description:
 *   Configure a GPIO pin based on bit-encoded description of the pin.
 *
 ****************************************************************************/

int sam3u_configgpio(uint16_t cfgset)
{
  uintptr_t base = sam3u_gpiobase(cfgset);
  uint32_t  pin  = sam3u_gpiopin(cfgset);
  int       ret;

  switch (cfgset & GPIO_MODE_MASK)
    {    
      case GPIO_INPUT:
        ret = sam3u_configinput(base, pin, cfgset);
        break;
    
      case GPIO_OUTPUT:
        ret = sam3u_configoutput(base, pin, cfgset);
        break;
    
      case GPIO_PERIPHA:
      case GPIO_PERIPHB:
        ret = sam3u_configperiph(base, pin, cfgset);
        break;
   
      default:
        ret = -EINVAL;
        break;
    }
  return ret;
}

/****************************************************************************
 * Name: sam3u_gpiowrite
 *
 * Description:
 *   Write one or zero to the selected GPIO pin
 *
 ****************************************************************************/

void sam3u_gpiowrite(uint16_t pinset, bool value)
{
  uintptr_t base = sam3u_gpiobase(pinset);
  uint32_t  pin  = sam3u_gpiopin(pinset);

  if (value)
    {
      putreg32(pin, base+SAM3U_PIO_SODR_OFFSET);
    }
  else
    {
      putreg32(pin, base+SAM3U_PIO_CODR_OFFSET);
    }
}

/****************************************************************************
 * Name: sam3u_gpioread
 *
 * Description:
 *   Read one or zero from the selected GPIO pin
 *
 ****************************************************************************/

bool sam3u_gpioread(uint16_t pinset)
{
  uintptr_t base = sam3u_gpiobase(pinset);
  uint32_t  pin  = sam3u_gpiopin(pinset);
  uint32_t  regval;

  if ((pinset & GPIO_MODE_MASK) == GPIO_OUTPUT)
    {
      regval = getreg32(base+SAM3U_PIO_ODSR_OFFSET);
    }
  else
    {
      regval = getreg32(base+SAM3U_PIO_PDSR_OFFSET);
    }

  return (regval & pin) != 0;
}