path: root/nuttx/arch/arm/src/lpc17xx/lpc178x_gpio.c

/****************************************************************************
 * arch/arm/src/lpc17xx/lpc178x_gpio.c
 *
 *   Copyright (C) 2010-2011, 2013 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *           With LPC178x extensions from Rommel Marcelo
 *
 * 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 <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <errno.h>
#include <debug.h>

#include <arch/irq.h>

#include "up_arch.h"
#include "chip.h"
#include "lpc17_gpio.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

/* Default input pin configuration */

#define DEFAULT_INPUT (GPIO_INPUT|GPIO_PULLUP)

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

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

/****************************************************************************
 * Public Data
 ****************************************************************************/
/* These tables have global scope because they are also used in
 * lpc17_gpiodbg.c
 */

/* We have to remember the configured interrupt setting.. PINs are not
 * actually set up to interrupt until the interrupt is enabled.
 */

#ifdef CONFIG_GPIO_IRQ
uint64_t g_intedge0;
uint64_t g_intedge2;
#endif

/* FIO register base addresses */

const uint32_t g_fiobase[GPIO_NPORTS] =
{
  LPC17_FIO0_BASE,
  LPC17_FIO1_BASE,
  LPC17_FIO2_BASE,
  LPC17_FIO3_BASE,
  LPC17_FIO4_BASE
#if GPIO_NPORTS > 5
  , LPC17_FIO5_BASE
#endif
};

/* Port 0 and Port 2 can provide a single interrupt for any combination of
 * port pins
 */

const uint32_t g_intbase[GPIO_NPORTS] =
{
  LPC17_GPIOINT0_BASE,
  0,
  LPC17_GPIOINT2_BASE,
  0,
  0
#if GPIO_NPORTS > 5
  , 0
#endif
};

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Name: lpc17_getioconmask
 *
 * Description:
 *   Get the LPC178x IOCON register mask.
 *
 *   Type D: FUNC, MODE, HYS, INV, SLEW, OD             -
 *   Type A: FUNC, MODE, INV, ADMODE, FILTER, OD, DACEN -P0[12:13,23:26],P1[30:31]
 *   Type U: FUNC                                       -P0[29:31]
 *   Type I: FUNC, INV, HS, HIDRIVE                     -P0[27:28], P5[2:3]
 *   Type W: FUNC, MODE, HYS, INV, FILTER, SLEW, OD     -P0[7:9]
 *
 ****************************************************************************/

#if 0 /* Not used */
static uint32_t lpc17_getioconmask(unsigned int port, unsigned int pin)
{
  uint32_t typemask = IOCON_TYPE_D_MASK;

  /* Select the mask based on pin usage */

  switch (port)
    {
      case 0:
        switch (pin)
          {
            case 7:
            case 8:
            case 9:
              typemask = IOCON_TYPE_W_MASK;
              break;

            case 12:
            case 13:
            case 23:
            case 24:
            case 25:
            case 26:
              typemask = IOCON_TYPE_A_MASK;
              break;

            case 27:
            case 28:
              typemask = IOCON_TYPE_I_MASK;
              break;

            case 29:
            case 30:
            case 31:
              typemask = IOCON_TYPE_U_MASK;
              break;

            default:
                break;
          }
        break;

      case 1:
        switch (pin)
          {
            case 30:
            case 31:
              typemask = IOCON_TYPE_A_MASK;
              break;

            default:
              break;
          }
        break;

      case 5:
        switch (pin)
          {
            case 2:
            case 3:
              typemask = IOCON_TYPE_I_MASK;
              break;

            default:
              break;
          }
        break;

      default:
        break;
    }

  return typemask;
}
#endif

/****************************************************************************
 * Name: lpc17_seti2cmode
 *
 * Description:
 *   Configure I2C pin drive mode.  Applies to Type I pins
 *
 ****************************************************************************/

static void lpc17_seti2cmode(unsigned int port,unsigned int pin, uint32_t value)
{
  uint32_t regaddr;
  uint32_t regval;

  regaddr = LPC17_IOCON_P(port, pin);
  regval  = getreg32(regaddr);
  regval &= ~IOCON_I2CMODE_MASK;
  regval |= ((value << IOCON_I2CMODE_SHIFT) & IOCON_I2CMODE_MASK);
  putreg32(regval, regaddr);
}

/****************************************************************************
 * Name: lpc17_setpinfunction
 *
 * Description:
 *   Select pin function.
 *
 ****************************************************************************/

static void lpc17_setpinfunction(unsigned int port, unsigned int pin,
                                 unsigned int value)
{
  uint32_t regaddr;
  uint32_t regval;

  regaddr = LPC17_IOCON_P(port, pin);
  regval  = getreg32(regaddr);

  regval &= ~IOCON_FUNC_MASK;
  regval |= ((value << IOCON_FUNC_SHIFT) & IOCON_FUNC_MASK);
  putreg32(regval, regaddr);
}

/****************************************************************************
 * Name: lpc17_setinvertinput
 *
 * Description:
 *   Configure pin input polarity.  Applies to Type D, A, I and W pins.
 *
 ****************************************************************************/

static void lpc17_setinvertinput(unsigned int port, unsigned int pin)
{
  uint32_t regaddr;
  uint32_t regval;

  regaddr = LPC17_IOCON_P(port, pin);
  regval  = getreg32(regaddr);
  regval |= IOCON_INV_MASK;
  putreg32(regval, regaddr);
}

/****************************************************************************
 * Name: lpc17_setslewfast
 *
 * Description:
 *   Configure pin mode slew rate drive.  Applies to Type D and Type W pins
 *
 ****************************************************************************/

static void lpc17_setslewmode(lpc17_pinset_t cfgset, unsigned int port,
                              unsigned int pin)
{
  uint32_t regaddr;
  uint32_t regval;
  uint32_t value;

  /* Decode the request output slew rate */

  value = ((cfgset & GPIO_SLEW_MASK) >> GPIO_SLEW_SHIFT);

  /* Get the current IOCON register contents */

  regaddr = LPC17_IOCON_P(port, pin);
  regval  = getreg32(regaddr);

  /* Set the driver slew rate */

  regval &= ~IOCON_SLEW_MASK;
  regval |= ((value << IOCON_SLEW_SHIFT) & IOCON_SLEW_MASK);
  putreg32(regval, regaddr);
}

/****************************************************************************
 * Name: lpc17_setmodedigital
 *
 * Description:
 *   Configure pin mode as analog or digital IO. Applies to Type A pins
 *
 ****************************************************************************/

#if 0 /* Not used */
static void lpc17_setmodedigital(unsigned int port, unsigned int pin)
{
  uint32_t regaddr;
  uint32_t regval;

  regaddr = LPC17_IOCON_P(port, pin);
  regval  = getreg32(regaddr);
  regval |= IOCON_ADMODE_MASK;
  putreg32(regval, regaddr);
}
#endif

/****************************************************************************
 * Name: lpc17_setmodeanalog
 *
 * Description:
 *   Configure pin mode as analog or digital IO. Applies to Type A pins
 *
 ****************************************************************************/

static void lpc17_setmodeanalog(unsigned int port, unsigned int pin)
{
  uint32_t regaddr;
  uint32_t regval;

  regaddr = LPC17_IOCON_P(port, pin);
  regval  = getreg32(regaddr);
  regval &= ~IOCON_ADMODE_MASK;
  putreg32(regval, regaddr);
}

/****************************************************************************
 * Name: lpc17_setdacenable
 *
 * Description:
 *   Configure DAC output. Applies to Type A pins P0:26 only
 *
 ****************************************************************************/

static void lpc17_setdacenable(unsigned int port, unsigned int pin)
{
  uint32_t regaddr;
  uint32_t regval;

  regaddr = LPC17_IOCON_P(port, pin);
  regval  = getreg32(regaddr);
  regval |= IOCON_DACEN_MASK;
  putreg32(regval, regaddr);
}

/****************************************************************************
 * Name: lpc17_setdacdisable
 *
 * Description:
 *   Configure DAC output. Applies to Type A pins P0:26 only
 *
 ****************************************************************************/

#if 0 /* Not used */
static void lpc17_setdacdisable(unsigned int port, unsigned int pin)
{
  uint32_t regaddr;
  uint32_t regval;

  regaddr = LPC17_IOCON_P(port, pin);
  regval  = getreg32(regaddr);
  regval &= ~IOCON_DACEN_MASK;
  putreg32(regval, regaddr);
}
#endif

/****************************************************************************
 * Name: lpc17_setfilter
 *
 * Description:
 *   Configure analog pin's glitch filter.  Applies to Type A and Type W pins
 *
 ****************************************************************************/

static void lpc17_setfilter(lpc17_pinset_t cfgset, unsigned int port,
                            unsigned int pin)
{
  uint32_t regaddr;
  uint32_t regval;
  uint32_t value;

  /* Decode the request input filter */

  value = ((cfgset & GPIO_FILTER_MASK) >> GPIO_FILTER_SHIFT);

  /* Get the current IOCON register contents */

  regaddr = LPC17_IOCON_P(port, pin);
  regval  = getreg32(regaddr);

  /* Set the input filter enable bit */

  regval &= ~IOCON_FILTER_MASK;
  regval |= ((value << IOCON_FILTER_SHIFT) & IOCON_FILTER_MASK);
  putreg32(regval, regaddr);
}

/****************************************************************************
 * Name: lpc17_setopendrain
 *
 * Description:
 *   Configure a GPIO's opendrain mode.  Applies to Type A, Type D, and
 *   Type W pins.
 *
 ****************************************************************************/

static void lpc17_setopendrain(unsigned int port, unsigned int pin)
{
  uint32_t regaddr;
  uint32_t regval;

  regaddr = LPC17_IOCON_P(port, pin);
  regval  = getreg32(regaddr);
  regval |= IOCON_OD_MASK;
  putreg32(regval, regaddr);
}

/****************************************************************************
 * Name: lpc17_clropendrain
 *
 * Description:
 *   Configure a GPIO's opendrain mode.  Applies to Type A, Type D, and
 *   Type W pins.
 *
 ****************************************************************************/

static void lpc17_clropendrain(unsigned int port, unsigned int pin)
{
  uint32_t regaddr;
  uint32_t regval;

  regaddr = LPC17_IOCON_P(port, pin);
  regval  = getreg32(regaddr);
  regval &= ~IOCON_OD_MASK;
  putreg32(regval, regaddr);
}

/****************************************************************************
 * Name: lpc17_sethysteresis
 *
 * Description:
 *   Configure a GPIO's hysteresis mode.  Applies to Type D and Type W pins
 *   Default is enabled.
 *
 ****************************************************************************/

static void lpc17_sethysteresis(lpc17_pinset_t cfgset, unsigned int port,
                                unsigned int pin)
{
  uint32_t regaddr;
  uint32_t regval;
  uint32_t value;

  /* Decode the request input buffer */

  value = ((cfgset & GPIO_HYSTERESIS) >> GPIO_INBUFF_SHIFT);

  /* Get the current IOCON register contents */

  regaddr = LPC17_IOCON_P(port, pin);
  regval  = getreg32(regaddr);

  /* Set the input buffer enable bit */

  regval &= ~IOCON_HYS_MASK;
  regval |= ((value << IOCON_HYS_SHIFT) & IOCON_HYS_MASK);
  putreg32(regval, regaddr);
}

/****************************************************************************
 * Name: lpc17_pullup
 *
 * Description:
 *   Clear and set the pin mode bits.  Applies to Type A, Type D, and
 *   Type W pins.
 *
 ****************************************************************************/

static void lpc17_setpullup(lpc17_pinset_t cfgset, unsigned int port,
                            unsigned int pin)
{
  uint32_t regaddr;
  uint32_t regval;
  uint32_t pinmode;

  /* Decode the request pull-up mode */

  pinmode = ((cfgset & GPIO_PUMODE_MASK) >> GPIO_PUMODE_SHIFT);

  /* Get the current IOCON register contents */

  regaddr = LPC17_IOCON_P(port, pin);
  regval  = getreg32(regaddr);

  /* Set the new mode bits */

  regval &= ~IOCON_MODE_MASK;
  regval |= ((pinmode << IOCON_MODE_SHIFT) & IOCON_MODE_MASK);
  putreg32(regval, regaddr);
}

/****************************************************************************
 * Name: lpc17_setintedge
 *
 * Description:
 *  Remember the configured interrupt edge.  We can't actually enable the
 *  the edge interrupts until the called calls IRQ enabled function.
 *
 ****************************************************************************/

#ifdef CONFIG_GPIO_IRQ
static void lpc17_setintedge(unsigned int port, unsigned int pin,
                             unsigned int value)
{
  uint64_t *intedge;
  unsigned int shift;

  /* Which word to we use? */

  if (port == 0)
    {
      intedge = &g_intedge0;
    }
  else if (port == 2)
    {
      intedge  = &g_intedge2;
    }
  else
    {
      return;
    }

  /* Set the requested value in the PINSEL register */

  shift     = pin << 1;
  *intedge &= ~((uint64_t)3     << shift);
  *intedge |=  ((uint64_t)value << shift);
}
#endif /* CONFIG_GPIO_IRQ */

/****************************************************************************
 * Name: lpc17_configinput
 *
 * Description:
 *   Configure a GPIO input pin based on bit-encoded description of the pin.
 *
 ****************************************************************************/

static inline int lpc17_configinput(lpc17_pinset_t cfgset, unsigned int port,
                                    unsigned int pin)
{
  uint32_t regval;
  uint32_t fiobase;
  uint32_t intbase;
  uint32_t pinmask = (1 << pin);

  /* Set up FIO registers */

  fiobase = g_fiobase[port];

  /* Set as input */

  regval  = getreg32(fiobase + LPC17_FIO_DIR_OFFSET);
  regval &= ~pinmask;
  putreg32(regval, fiobase + LPC17_FIO_DIR_OFFSET);

  /* Set up interrupt registers */

  intbase = g_intbase[port];
  if (intbase != 0)
    {
      /* Disable any rising edge interrupts */

      regval = getreg32(intbase + LPC17_GPIOINT_INTENR_OFFSET);
      regval &= ~pinmask;
      putreg32(regval, intbase + LPC17_GPIOINT_INTENR_OFFSET);

      /* Disable any falling edge interrupts */

      regval  = getreg32(intbase + LPC17_GPIOINT_INTENF_OFFSET);
      regval &= ~pinmask;
      putreg32(regval, intbase + LPC17_GPIOINT_INTENF_OFFSET);

      /* Forget about any falling/rising edge interrupt enabled */

#ifdef CONFIG_GPIO_IRQ
      lpc17_setintedge(port, pin, 0);
#endif
    }

  /* Set pull-up mode */

  lpc17_setpullup(cfgset, port, pin);

  /* Clear opendrain */

  lpc17_clropendrain(port, pin);

  /* Set input polarity */

  if ((cfgset & GPIO_INVERT) != 0)
    {
      lpc17_setinvertinput(port, pin);
    }

  /* Set input hysteresis */

  lpc17_sethysteresis(cfgset, port, pin);

  /* Set input filtering */

  lpc17_setfilter(cfgset, port, pin);

  /* Configure as GPIO */

  lpc17_setpinfunction(port, pin, IOCON_FUNC_GPIO);

  return OK;
}

/****************************************************************************
 * Name: lpc17_configinterrupt
 *
 * Description:
 *   Configure a GPIO interrupt pin based on bit-encoded description of the pin.
 *
 ****************************************************************************/

static inline int lpc17_configinterrupt(lpc17_pinset_t cfgset, unsigned int port,
                                        unsigned int pin)
{
  /* First, configure the port as a generic input so that we have a known
   * starting point and consistent behavior during the re-configuration.
   */

  (void)lpc17_configinput(cfgset, port, pin);

  /* Then just remember the rising/falling edge interrupt enabled */

  DEBUGASSERT(port == 0 || port == 2);
#ifdef CONFIG_GPIO_IRQ
  lpc17_setintedge(port, pin, (cfgset & GPIO_EDGE_MASK) >> GPIO_EDGE_SHIFT);
#endif
  return OK;
}

/****************************************************************************
 * Name: lpc17_configoutput
 *
 * Description:
 *   Configure a GPIO output pin based on bit-encoded description of the pin.
 *
 ****************************************************************************/

static inline int lpc17_configoutput(lpc17_pinset_t cfgset, unsigned int port,
                                     unsigned int pin)
{
  uint32_t fiobase;
  uint32_t regval;

  /* First, configure the port as a generic input so that we have a known
   * starting point and consistent behavior during the re-configuration.
   */

  (void)lpc17_configinput(DEFAULT_INPUT, port, pin);

  /* Now, reconfigure the pin as an output */

  fiobase = g_fiobase[port];
  regval  = getreg32(fiobase + LPC17_FIO_DIR_OFFSET);
  regval |= (1 << pin);
  putreg32(regval, fiobase + LPC17_FIO_DIR_OFFSET);

  /* Check for open drain output */

  if ((cfgset & GPIO_OPEN_DRAIN) != 0)
    {
      /* Set pull-up mode.  This normally only applies to input pins, but does have
       * meaning if the port is an open drain output.
       */

      lpc17_setpullup(cfgset, port, pin);

      /* Select open drain output */

      lpc17_setopendrain(port, pin);
    }

  /* Set output slew rate */

  lpc17_setslewmode(cfgset, port, pin);

  /* Set the initial value of the output */

  lpc17_gpiowrite(cfgset, ((cfgset & GPIO_VALUE) != GPIO_VALUE_ZERO));

  return OK;
}

/****************************************************************************
 * Name: lpc17_configalternate
 *
 * Description:
 *   Configure a GPIO alternate function pin based on bit-encoded description
 *   of the pin.
 *
 ****************************************************************************/

static int lpc17_configalternate(lpc17_pinset_t cfgset, unsigned int port,
                                 unsigned int pin, uint32_t alt)
{
  uint32_t i2cmode;

  /* First, configure the port as an input so that we have a known
   * starting point and consistent behavior during the re-configuration.
   */

  (void)lpc17_configinput(DEFAULT_INPUT, port, pin);

  /* Set pull-up mode */

  lpc17_setpullup(cfgset, port, pin);

  /* Check for analog mode */

  if ((cfgset & GPIO_MODE_ANALOG) != 0)
    {
      lpc17_setmodeanalog(port, pin);

      /* Check for DAC output enable */

      if ((cfgset & GPIO_DACEN) != 0)
        {
          lpc17_setdacenable(port, pin);
        }
    }

  /* Check for I2C modes */

  if ((cfgset & (GPIO_I2CHS | GPIO_HIDRIVE)) != 0)
    {
      /* Isolate the I2C mode bits */

      i2cmode = ((cfgset & GPIO_I2CMODE_MASK) >> GPIO_I2CMODE_SHIFT);

      /* Set I2C Modes */

      lpc17_seti2cmode(port, pin, i2cmode);
    }

  /* Check for open drain output */

  if ((cfgset & GPIO_OPEN_DRAIN) != 0)
    {
      /* Select open drain output */

      lpc17_setopendrain(port, pin);
    }

  /* Set output slew rate */

  lpc17_setslewmode(cfgset, port, pin);

  /* Select the alternate pin */

  lpc17_setpinfunction(port, pin, alt);

  return OK;
}

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

/****************************************************************************
 * Name: lpc17_configgpio
 *
 * Description:
 *   Configure a GPIO pin based on bit-encoded description of the pin.
 *
 ****************************************************************************/

int lpc17_configgpio(lpc17_pinset_t cfgset)
{
  unsigned int port;
  unsigned int pin;

  int ret = -EINVAL;

  /* Verify that this hardware supports the select GPIO port */

  port = (cfgset & GPIO_PORT_MASK) >> GPIO_PORT_SHIFT;
  if (port < GPIO_NPORTS)
    {
      /* Get the pin number and select the port configuration register for
       * that pin.
       */

      pin = (cfgset & GPIO_PIN_MASK) >> GPIO_PIN_SHIFT;

      /* Handle according to pin function */

      switch (cfgset & GPIO_FUNC_MASK)
        {
        case GPIO_INPUT:   /* GPIO input pin */
          ret = lpc17_configinput(cfgset, port, pin);
          break;

        case GPIO_INTFE:   /* GPIO interrupt falling edge */
        case GPIO_INTRE:   /* GPIO interrupt rising edge */
        case GPIO_INTBOTH: /* GPIO interrupt both edges */
          ret = lpc17_configinterrupt(cfgset, port, pin);
          break;

        case GPIO_OUTPUT:  /* GPIO outpout pin */
          ret = lpc17_configoutput(cfgset, port, pin);
          break;

        case GPIO_ALT1:    /* Alternate function 1 */
          ret = lpc17_configalternate(cfgset, port, pin, IOCON_FUNC_ALT1);
          break;

        case GPIO_ALT2:    /* Alternate function 2 */
          ret = lpc17_configalternate(cfgset, port, pin, IOCON_FUNC_ALT2);
          break;

        case GPIO_ALT3:    /* Alternate function 3 */
          ret = lpc17_configalternate(cfgset, port, pin, IOCON_FUNC_ALT3);
          break;

        case GPIO_ALT4:    /* Alternate function 4 */
          ret = lpc17_configalternate(cfgset, port, pin, IOCON_FUNC_ALT4);
          break;

        case GPIO_ALT5:    /* Alternate function 5 */
          ret = lpc17_configalternate(cfgset, port, pin, IOCON_FUNC_ALT5);
          break;

        case GPIO_ALT6:    /* Alternate function 6 */
          ret = lpc17_configalternate(cfgset, port, pin, IOCON_FUNC_ALT6);
          break;

        case GPIO_ALT7:    /* Alternate function 7 */
          ret = lpc17_configalternate(cfgset, port, pin, IOCON_FUNC_ALT7);
          break;

        default:
          break;
        }
    }

  return ret;
}

/****************************************************************************
 * Name: lpc17_gpiowrite
 *
 * Description:
 *   Write one or zero to the selected GPIO pin
 *
 ****************************************************************************/

void lpc17_gpiowrite(lpc17_pinset_t pinset, bool value)
{
  uint32_t fiobase;
  uint32_t offset;
  unsigned int port;
  unsigned int pin;

  port = (pinset & GPIO_PORT_MASK) >> GPIO_PORT_SHIFT;
  if (port < GPIO_NPORTS)
    {
      /* Get the port base address */

      fiobase = g_fiobase[port];

      /* Get the pin number  */

      pin = (pinset & GPIO_PIN_MASK) >> GPIO_PIN_SHIFT;

      /* Set or clear the output on the pin */

      if (value)
        {
          offset = LPC17_FIO_SET_OFFSET;
        }
      else
        {
          offset = LPC17_FIO_CLR_OFFSET;
        }

      putreg32((1 << pin), fiobase + offset);
    }
}

/****************************************************************************
 * Name: lpc17_gpioread
 *
 * Description:
 *   Read one or zero from the selected GPIO pin
 *
 ****************************************************************************/

bool lpc17_gpioread(lpc17_pinset_t pinset)
{
  uint32_t fiobase;
  unsigned int port;
  unsigned int pin;

  port = (pinset & GPIO_PORT_MASK) >> GPIO_PORT_SHIFT;
  if (port < GPIO_NPORTS)
    {
      /* Get the port base address */

      fiobase = g_fiobase[port];

      /* Get the pin number and return the input state of that pin */

      pin = (pinset & GPIO_PIN_MASK) >> GPIO_PIN_SHIFT;
      return ((getreg32(fiobase + LPC17_FIO_PIN_OFFSET) & (1 << pin)) != 0);
    }

  return false;
}