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nuttx/arch/arm/src/lpc43xx/lpc43_gpio.c
patacongo 90dd12bc15 Several fixes to LPC43 pin and GPIO configuration 
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4925 42af7a65-404d-4744-a932-0658087f49c3
2012-07-10 18:33:14 +00:00

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/****************************************************************************
* arch/arm/src/lpc43/lpc43_gpio.c
*
* Copyright (C) 2012 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 <arch/board/board.h>
#include <nuttx/config.h>
#include <nuttx/arch.h>
#include <errno.h>
#include <debug.h>
#include "up_arch.h"
#include "lpc43_gpio.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: lpc43_configinput
*
* Description:
* Configure a GPIO pin as an input (or pre-configured the pin for an
* interrupt).
*
* Returned Value:
* None
*
* Assumptions:
* Interrupts are disabled so that read-modify-write operations are safe.
*
****************************************************************************/
static inline void lpc43_configinput(uint16_t gpiocfg,
unsigned int port, unsigned int pin)
{
uintptr_t regaddr;
uint32_t regval;
/* Then configure the pin as a normal input by clearing the corresponding
* bit in the GPIO DIR register for the port.
*/
regaddr = LPC43_GPIO_DIR(port);
regval = getreg32(regaddr);
regval &= ~GPIO_DIR(pin);
putreg32(regval, regaddr);
/* To be able to read the signal on the GPIO input, the input
* buffer must be enabled in the syscon block for the corresponding pin.
* This should have been done when the pin was configured as a GPIO.
*/
}
/****************************************************************************
* Name: lpc43_configoutput
*
* Description:
* Configure a GPIO pin as an output.
*
* Returned Value:
* None
*
* Assumptions:
* Interrupts are disabled so that read-modify-write operations are safe.
*
****************************************************************************/
static inline void lpc43_configoutput(uint16_t gpiocfg,
unsigned int port, unsigned int pin)
{
uintptr_t regaddr;
uint32_t regval;
/* Then configure the pin as an output by setting the corresponding
* bit in the GPIO DIR register for the port.
*/
regaddr = LPC43_GPIO_DIR(port);
regval = getreg32(regaddr);
regval |= GPIO_DIR(pin);
putreg32(regval, regaddr);
/* Set the initial value of the output */
lpc43_gpio_write(gpiocfg, GPIO_IS_ONE(gpiocfg));
/* To be able to read the signal on the GPIO input, the input
* buffer must be enabled in the syscon block for the corresponding pin.
* This should have been done when the pin was configured as a GPIO.
*/
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: lpc43_gpio_config
*
* Description:
* Configure a GPIO based on bit-encoded description of the pin. NOTE:
* The pin *must* have first been configured for GPIO usage with a
* corresponding call to lpc43_pin_config().
*
* Returned Value:
* OK on success; A negated errno value on failure.
*
****************************************************************************/
int lpc43_gpio_config(uint16_t gpiocfg)
{
unsigned int port = ((gpiocfg & GPIO_PORT_MASK) >> GPIO_PORT_SHIFT);
unsigned int pin = ((gpiocfg & GPIO_PIN_MASK) >> GPIO_PIN_SHIFT);
irqstate_t flags;
int ret = OK;
DEBUGASSERT(port < NUM_GPIO_PORTS && pin < NUM_GPIO_PINS);
/* Handle the GPIO configuration by the basic mode of the pin */
flags = irqsave();
switch (gpiocfg & GPIO_MODE_MASK)
{
case GPIO_MODE_INPUT: /* GPIO input pin */
lpc43_configinput(gpiocfg, port, pin);
break;
case GPIO_MODE_OUTPUT: /* GPIO output pin */
lpc43_configoutput(gpiocfg, port, pin);
break;
case GPIO_MODE_PININTR: /* GPIO pin interrupt */
lpc43_configinput(gpiocfg, port, pin);
#ifdef CONFIG_GPIO_IRQ
ret = lpc43_gpioint_pinconfig(gpiocfg);
#endif
break;
case GPIO_MODE_GRPINTR: /* GPIO group interrupt */
lpc43_configinput(gpiocfg, port, pin);
#ifdef CONFIG_GPIO_IRQ
ret = lpc43_gpioint_grpconfig(gpiocfg);
#endif
break;
default :
sdbg("ERROR: Unrecognized pin mode: %04x\n", gpiocfg);
ret = -EINVAL;
break;
}
irqrestore(flags);
return ret;
}
/****************************************************************************
* Name: lpc43_gpio_write
*
* Description:
* Write one or zero to the selected GPIO pin
*
* Returned Value:
* None
*
****************************************************************************/
void lpc43_gpio_write(uint16_t gpiocfg, bool value)
{
unsigned int port = ((gpiocfg & GPIO_PORT_MASK) >> GPIO_PORT_SHIFT);
unsigned int pin = ((gpiocfg & GPIO_PIN_MASK) >> GPIO_PIN_SHIFT);
DEBUGASSERT(port < NUM_GPIO_PORTS && pin < NUM_GPIO_PINS);
/* Write the value (0 or 1). To the pin byte register */
putreg8((uint8_t)value, LPC43_GPIO_B(port, pin));
}
/****************************************************************************
* Name: lpc43_gpio_read
*
* Description:
* Read one or zero from the selected GPIO pin
*
* Returned Value:
* The boolean state of the input pin
*
****************************************************************************/
bool lpc43_gpio_read(uint16_t gpiocfg)
{
unsigned int port = ((gpiocfg & GPIO_PORT_MASK) >> GPIO_PORT_SHIFT);
unsigned int pin = ((gpiocfg & GPIO_PIN_MASK) >> GPIO_PIN_SHIFT);
DEBUGASSERT(port < NUM_GPIO_PORTS && pin < NUM_GPIO_PINS);
/* Get the value of the pin from the pin byte register */
return (getreg8(LPC43_GPIO_B(port, pin)) & GPIO_B) != 0;
}
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