path: root/nuttx/arch/arm/src/samd/sam_port.c

/****************************************************************************
 * arch/arm/src/samd/sam_port.c
 *
 *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * References:
 *   "Atmel SAM D20J / SAM D20G / SAM D20E ARM-Based Microcontroller
 *   Datasheet", 42129J�SAM�12/2013
 *
 * 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 "sam_port.h"
#include "chip/sam_port.h"

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

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

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

#ifdef CONFIG_DEBUG_PORT
static const char g_portchar[2]   = { 'A', 'B' };
#endif

/****************************************************************************
 * Private Function Prototypes
 ****************************************************************************/
/****************************************************************************
 * Name: sam_portbase
 *
 * Description:
 *   Return the base address of the PORT register set
 *
 ****************************************************************************/

static inline uintptr_t sam_portbase(port_pinset_t pinset)
{
  int port = (pinset & PORT_MASK) >> PORT_SHIFT;
  return SAM_PORTN_BASE(port);
}

/****************************************************************************
 * Name: sam_portpin
 *
 * Description:
 *   Returun the base address of the PORT register set
 *
 ****************************************************************************/

static inline int sam_portpin(port_pinset_t pinset)
{
  return 1 << ((pinset & PORT_PIN_MASK) >> PORT_PIN_SHIFT);
}

/****************************************************************************
 * Name: sam_configinput
 *
 * Description:
 *   Configure a PORT input pin based on bit-encoded description of the pin.
 *   This function serves the dual role of putting all pins into a known,
 *   initial state.  Hence, it is overkill for what really needs to be done.
 *
 * Assumption:
 *   sam_configreset has been called to put the pin into the default reset
 *   state.
 *
 ****************************************************************************/

static inline void sam_configinput(uintptr_t base, port_pinset_t pinset)
{
  uint32_t regval;
  uint32_t bit;
  int pin;

  /* Decode pin information */

  pin = (pinset & PORT_PIN_MASK) >> PORT_PIN_SHIFT;
  bit = (1 << pin);

  /* Direction bit is already zero (input) */
  /* Enable the I/O synchronizer? */

  if ((pinset & PORT_SYNCHRONIZER_MASK) == PORT_SYNCHRONIZER_ON)
    {
      regval  = getreg32(base + SAM_PORT_CTRL_OFFSET);
      regval |= bit;
      putreg32(regval, base + SAM_PORT_CTRL_OFFSET);
    }

  /* Set the pin configuration */

  regval = (PORT_WRCONFIG_WRPINCFG | PORT_WRCONFIG_WRPMUX | PORT_WRCONFIG_INEN);
  if (pin > 16)
    {
       /* Select the upper half word and adjust the bit setting */

       regval  = PORT_WRCONFIG_HWSEL;
       pin    -= 16;
    }

  regval |= PORT_WRCONFIG_PINMASK(pin);

  /* Check for pull-up/down selection */

  switch (pinset & PORT_PULL_MASK)
    {
      case PORT_PULL_UP:
        {
          /* Select pull-up by setting the corresponding bit in OUT
           * register.
           */

          putreg32(bit, base + SAM_PORT_OUTSET_OFFSET);
        }
        /* Fall through */

      case PORT_PULL_DOWN:
        {
          regval |= PORT_WRCONFIG_PULLEN;
        }
        break;

      default:
      case PORT_PULL_NONE:
        break;
    }

  /* Configure the pin as an input */ 
 
  putreg32(regval, base + SAM_PORT_WRCONFIG_OFFSET);
}

/****************************************************************************
 * Name: sam_configinterrupt
 *
 * Description:
 *   Configure a PORT interrupt pin based on bit-encoded description of the
 *   pin.
 *
 * Assumption:
 *   sam_configreset has been called to put the pin into the default reset
 *   state:
 *
 ****************************************************************************/

static inline void sam_configinterrupt(uintptr_t base, port_pinset_t pinset)
{
#warning Missing logic
}

/****************************************************************************
 * Name: sam_configoutput
 *
 * Description:
 *   Configure a PORT output pin based on bit-encoded description of the pin.
 *
 * Assumption:
 *   sam_configreset has been called to put the pin into the default reset
 *   state.
 *
 ****************************************************************************/

static inline void sam_configoutput(uintptr_t base, port_pinset_t pinset)
{
  uint32_t regval;
  uint32_t bit;
  int pin;

  /* Decode pin information */

  pin = (pinset & PORT_PIN_MASK) >> PORT_PIN_SHIFT;
  bit = (1 << pin);

  /* Set the direction bit to configure the pin as an input */

  putreg32(bit, base + SAM_PORT_DIRSET_OFFSET);

  /* Set the initial output value to high? */

  if ((pinset & PORT_OUTVALUE_MASK) == PORT_OUTPUT_SET)
    {
      putreg32(bit, base + SAM_PORT_OUTSET_OFFSET);
    }

  /* Set the pin configuration.  This will be an output with the input
   * buffer enabled.
   */

  regval = (PORT_WRCONFIG_WRPINCFG | PORT_WRCONFIG_WRPMUX | PORT_WRCONFIG_INEN);
  if (pin > 16)
    {
       /* Select the upper half word and adjust the bit setting */

       regval  = PORT_WRCONFIG_HWSEL;
       pin    -= 16;
    }

  regval |= PORT_WRCONFIG_PINMASK(pin);

  /* Check for pull-up/down selection */

  switch (pinset & PORT_PULL_MASK)
    {
      case PORT_PULL_UP:
        {
          /* Select pull-up by setting the corresponding bit in OUT
           * register.
           */

          putreg32(bit, base + SAM_PORT_OUTSET_OFFSET);
        }
        /* Fall through */

      case PORT_PULL_DOWN:
        {
          regval |= PORT_WRCONFIG_PULLEN;
        }
        break;

      default:
      case PORT_PULL_NONE:
        break;
    }

  /* Select higher strength drive? */

  if ((pinset & PORT_DRIVE_MASK) == PORT_DRIVE_HIGH)
    {
      regval |= PORT_WRCONFIG_DRVSTR;
    }

  /* Configure the pin as an output */ 
 
  putreg32(regval, base + SAM_PORT_WRCONFIG_OFFSET);
}

/****************************************************************************
 * Name: sam_configperiph
 *
 * Description:
 *   Configure a PORT pin driven by a peripheral based on bit-encoded
 *   description of the pin.
 *
 * Assumption:
 *   sam_configreset has been called to put the pin into the default reset
 *   state.
 *
 ****************************************************************************/

static inline void sam_configperiph(uintptr_t base, port_pinset_t pinset)
{
  uint32_t regval;
  uint32_t bit;
  uint32_t func;
  int pin;

  /* Decode pin information */

  pin = (pinset & PORT_PIN_MASK) >> PORT_PIN_SHIFT;
  bit = (1 << pin);

  /* Set the pin configuration.  This will be an peripheral with the
   * selected function.
   */

  regval = (PORT_WRCONFIG_WRPINCFG | PORT_WRCONFIG_WRPMUX | PORT_WRCONFIG_PMUXEN);
  if (pin > 16)
    {
       /* Select the upper half word and adjust the bit setting */

       regval  = PORT_WRCONFIG_HWSEL;
       pin    -= 16;
    }

  regval |= PORT_WRCONFIG_PINMASK(pin);

  /* Set the pin function */

  func   = (pinset & PORT_FUNC_MASK) >> PORT_FUNC_SHIFT;
  regval = (func << PORT_WRCONFIG_PMUX_SHIFT);

  /* Check for pull-up/down selection */

  switch (pinset & PORT_PULL_MASK)
    {
      case PORT_PULL_UP:
        {
          /* Select pull-up by setting the corresponding bit in OUT
           * register.
           */

          putreg32(bit, base + SAM_PORT_OUTSET_OFFSET);
        }
        /* Fall through */

      case PORT_PULL_DOWN:
        {
          regval |= PORT_WRCONFIG_PULLEN;
        }
        break;

      default:
      case PORT_PULL_NONE:
        break;
    }

  /* Configure the pin for the peripheral function */ 
 
  putreg32(regval, base + SAM_PORT_WRCONFIG_OFFSET);
}

/****************************************************************************
 * Name: sam_configreset
 *
 * Description:
 *   Configure a PORT pin in the default, reset state.
 *
 ****************************************************************************/

static inline void sam_configreset(uintptr_t base, port_pinset_t pinset)
{
  uint32_t regval;
  uint32_t bit;
  int pin;

  /* Decode pin information */

  pin = (pinset & PORT_PIN_MASK) >> PORT_PIN_SHIFT;
  bit = (1 << pin);

  /* Set the direction bit to zero (input) */

  putreg32(bit, base + SAM_PORT_DIRCLR_OFFSET);

  /* Disable the I/O synchronizer */

  regval = getreg32(base + SAM_PORT_CTRL_OFFSET);
  regval &= ~bit;
  putreg32(regval, base + SAM_PORT_CTRL_OFFSET);

  /* Assume input pull-down or output value low */

  putreg32(bit, base + SAM_PORT_OUTCLR_OFFSET);

  /* Set the pin configuration */

  regval = (PORT_WRCONFIG_WRPINCFG | PORT_WRCONFIG_WRPMUX);
  if (pin > 16)
    {
       /* Select the upper half word and adjust the bit setting */

       regval  = PORT_WRCONFIG_HWSEL;
       pin    -= 16;
    }

  regval |= PORT_WRCONFIG_PINMASK(pin);

  /* Disable the peripheral multiplexor, disable the input, disable
   * pull-up/down, reset driver strength, etc.
   */
 
  putreg32(regval, base + SAM_PORT_WRCONFIG_OFFSET);
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

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

int sam_configport(port_pinset_t pinset)
{
  uintptr_t base = sam_portbase(pinset);
  irqstate_t flags;

  /* Make sure that all operations on the port are atomic */

  flags = irqsave();

  /* Put the PORT in the known, reset state.  */

  sam_configreset(base, pinset);

  /* Then put the PORT into the requested state */

  switch (pinset & PORT_MODE_MASK)
    {
      case PORT_INPUT:
        sam_configinput(base, pinset);
        break;

      case PORT_OUTPUT:
        sam_configoutput(base, pinset);
        break;

      case PORT_PERIPHERAL:
        sam_configperiph(base, pinset);
        break;

      case PORT_INTERRUPT:
        sam_configinterrupt(base, pinset);
        break;

      default:
        break;
    }

  irqrestore(flags);
  return OK;
}

/****************************************************************************
 * Name: sam_portwrite
 *
 * Description:
 *   Write one or zero to the selected PORT pin
 *
 ****************************************************************************/

void sam_portwrite(port_pinset_t pinset, bool value)
{
  uintptr_t base = sam_portbase(pinset);
  uint32_t  pin  = sam_portpin(pinset);

  if (value)
    {
      putreg32(pin, base + SAM_PORT_OUTSET_OFFSET);
    }
  else
    {
      putreg32(pin, base + SAM_PORT_OUTCLR_OFFSET);
    }
}

/****************************************************************************
 * Name: sam_portread
 *
 * Description:
 *   Read one or zero from the selected PORT pin
 *
 ****************************************************************************/

bool sam_portread(port_pinset_t pinset)
{
  uintptr_t base = sam_portbase(pinset);
  uint32_t  pin  = sam_portpin(pinset);

  return (getreg32(base + SAM_PORT_IN_OFFSET) & pin) != 0;
}

/************************************************************************************
 * Function:  sam_dumpport
 *
 * Description:
 *   Dump all PORT registers associated with the base address of the provided pinset.
 *
 ************************************************************************************/

#ifdef CONFIG_DEBUG_PORT
int sam_dumpport(uint32_t pinset, const char *msg)
{
  irqstate_t    flags;
  uintptr_t     base;
  unsigned int  pin;
  unsigned int  port;

  /* Get the base address associated with the PIO port */

  pin  = sam_portpin(pinset);
  port = (pinset & PORT_MASK) >> PORT_SHIFT;
  base = SAM_PORTN_BASE(port);

  /* The following requires exclusive access to the PORT registers */

  flags = irqsave();
  lldbg("PORT%c pinset: %08x base: %08x -- %s\n",
        g_portchar[port], pinset, base, msg);
  lldbg("  DIR: %08x OUT: %08x IN: %08x\n",
        getreg32(base + SAM_PORT_DIR_OFFSET),
        getreg32(base + SAM_PORT_OUT_OFFSET),
        getreg32(base + SAM_PORT_IN_OFFSET));
  lldbg("  CTRL: %08x WRCONFIG: %08x\n",
        getreg32(base + SAM_PORT_CTRL_OFFSET),
        getreg32(base + SAM_PORT_WRCONFIG_OFFSET));
  lldbg("  PMUX[%08x]: %02x PINCFG[%08x]: %02x\n",
        base + SAM_PORT_PMUX_OFFSET(pin),
        getreg8(base + SAM_PORT_PMUX_OFFSET(pin)),
        base + SAM_PORT_PINCFG_OFFSET(pin),
        getreg8(base + SAM_PORT_PINCFG_OFFSET(pin)));

  irqrestore(flags);
  return OK;
}
#endif