nuttx/boards/arm/lpc17xx_40xx/lpc4088-quickstart/src/lpc17_40_buttons.c

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/****************************************************************************
* boards/arm/lpc17xx_40xx/lpc4088-quickstart/src/lpc17_40_buttons.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <stdbool.h>
#include <errno.h>
#include <nuttx/arch.h>
#include <nuttx/board.h>
#include <nuttx/irq.h>
#include <arch/board/board.h>
#include "lpc17_40_gpio.h"
#include "lpc4088-quickstart.h"
#ifdef CONFIG_ARCH_BUTTONS
/****************************************************************************
* Private Data
****************************************************************************/
/* The LPC4088 Quickstart supports several buttons.
* All will read "1" when open and "0" when closed
*
* USER1 -- Connected to P2[10]
*
* The switch is connected to ground and should be pulled up and sensed
* with a value of '0' when closed.
*/
/* Pin configuration for each LPC4088 Quickstart button. This array is
* indexed by the BUTTON_* and JOYSTICK_* definitions in board.h
*/
static const lpc17_40_pinset_t g_buttoncfg[NUM_BUTTONS] =
{
GPIO_USER1
};
#if defined(CONFIG_ARCH_IRQBUTTONS) && defined(CONFIG_LPC17_40_GPIOIRQ)
/* This array provides the mapping from button ID numbers to button IRQ
* numbers.
*/
static const uint8_t g_buttonirq[NUM_BUTTONS] =
{
GPIO_USER1_IRQ
};
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: board_button_initialize
*
* Description:
* board_button_initialize() must be called to initialize button resources.
* After that, board_buttons() may be called to collect the current state
* of all buttons or board_button_irq() may be called to register button
* interrupt handlers.
*
****************************************************************************/
uint32_t board_button_initialize(void)
{
int i;
/* Configure the GPIO pins as interrupting inputs. */
for (i = 0; i < NUM_BUTTONS; i++)
{
lpc17_40_configgpio(g_buttoncfg[i]);
}
return NUM_BUTTONS;
}
/****************************************************************************
2014-01-24 20:59:24 +01:00
* Name: board_buttons
*
* Description:
* board_button_initialize() must be called to initialize button resources.
* After that, board_buttons() may be called to collect the current state
* of all buttons.
*
2014-01-24 20:59:24 +01:00
* board_buttons() may be called at any time to harvest the state of every
* button. The state of the buttons is returned as a bitset with one
* bit corresponding to each button: If the bit is set, then the button
* is pressed. See the BOARD_BUTTON_*_BIT and BOARD_JOYSTICK_*_BIT
* definitions in board.h for the meaning of each bit.
*
****************************************************************************/
uint32_t board_buttons(void)
{
uint32_t ret = 0;
int i;
/* Check that state of each key */
for (i = 0; i < NUM_BUTTONS; i++)
{
/* A LOW value means that the key is pressed. */
bool released = lpc17_40_gpioread(g_buttoncfg[i]);
/* Accumulate the set of depressed (not released) keys */
if (!released)
{
ret |= (1 << i);
}
}
return ret;
}
/****************************************************************************
* Button support.
*
* Description:
* board_button_initialize() must be called to initialize button resources.
* After that, board_button_irq() may be called to register button
* interrupt handlers.
*
* board_button_irq() may be called to register an interrupt handler that
* will be called when a button is depressed or released. The ID value is
* a button enumeration value that uniquely identifies a button resource.
* See the BOARD_BUTTON_* and BOARD_JOYSTICK_* definitions in board.h for
* the meaning of enumeration values.
*
* Note that board_button_irq() also enables button interrupts. Button
* interrupts will remain enabled after the interrupt handler is attached.
* Interrupts may be disabled (and detached) by calling board_button_irq
* with irqhandler equal to NULL.
*
****************************************************************************/
#if defined(CONFIG_ARCH_IRQBUTTONS) && defined(CONFIG_LPC17_40_GPIOIRQ)
int board_button_irq(int id, xcpt_t irqhandler, FAR void *arg)
{
irqstate_t flags;
int ret = -EINVAL;
int irq;
/* Verify that the button ID is within range */
if ((unsigned)id < NUM_BUTTONS)
{
/* Get the IRQ number for the button; A value of zero indicates that
* the button does not support the interrupt function.
*/
irq = g_buttonirq[id];
if (irq > 0)
{
/* Disable interrupts until we are done */
flags = enter_critical_section();
/* Configure the interrupt. Either attach and enable the new
* interrupt or disable and detach the old interrupt handler.
*/
if (irqhandler)
{
/* Attach then enable the new interrupt handler */
irq_attach(irq, irqhandler, arg);
up_enable_irq(irq);
}
else
{
/* Disable then detach the old interrupt handler */
up_disable_irq(irq);
irq_detach(irq);
}
leave_critical_section(flags);
}
ret = OK;
}
return ret;
}
#endif
#endif /* CONFIG_ARCH_BUTTONS */