507 lines
14 KiB
C
507 lines
14 KiB
C
/****************************************************************************
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* drivers/ioexpander/gpio.c
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*
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* Copyright (C) 2016, 2018 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <sys/types.h>
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#include <stdio.h>
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#include <string.h>
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#include <signal.h>
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#include <assert.h>
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#include <errno.h>
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#include <nuttx/fs/fs.h>
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#include <nuttx/ioexpander/gpio.h>
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#ifdef CONFIG_DEV_GPIO
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/****************************************************************************
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* Private Function Prototypes
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****************************************************************************/
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static int gpio_handler(FAR struct gpio_dev_s *dev, uint8_t pin);
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static int gpio_open(FAR struct file *filep);
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static int gpio_close(FAR struct file *filep);
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static ssize_t gpio_read(FAR struct file *filep, FAR char *buffer,
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size_t buflen);
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static ssize_t gpio_write(FAR struct file *filep, FAR const char *buffer,
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size_t buflen);
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static int gpio_ioctl(FAR struct file *filep, int cmd,
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unsigned long arg);
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/****************************************************************************
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* Private Data
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****************************************************************************/
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static const struct file_operations g_gpio_drvrops =
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{
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gpio_open, /* open */
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gpio_close, /* close */
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gpio_read, /* read */
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gpio_write, /* write */
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NULL, /* seek */
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gpio_ioctl /* ioctl */
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#ifndef CONFIG_DISABLE_POLL
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, NULL /* poll */
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#endif
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#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
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, NULL /* unlink */
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#endif
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};
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/****************************************************************************
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* Name: gpio_handler
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*
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* Description:
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* GPIO interrupt callback function.
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*
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****************************************************************************/
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static int gpio_handler(FAR struct gpio_dev_s *dev, uint8_t pin)
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{
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int i;
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DEBUGASSERT(dev != NULL);
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for (i = 0; i < CONFIG_DEV_GPIO_NSIGNALS; i++)
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{
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FAR struct gpio_signal_s *signal = &dev->gp_signals[i];
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if (signal->gp_pid == 0)
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{
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break;
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}
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nxsig_notification(signal->gp_pid, &signal->gp_event,
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SI_QUEUE, &signal->gp_work);
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}
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return OK;
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}
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/****************************************************************************
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* Name: gpio_open
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*
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* Description:
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* Standard character driver open method.
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*
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****************************************************************************/
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static int gpio_open(FAR struct file *filep)
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{
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return OK;
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}
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/****************************************************************************
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* Name: gpio_close
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*
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* Description:
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* Standard character driver close method.
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*
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****************************************************************************/
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static int gpio_close(FAR struct file *filep)
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{
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return OK;
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}
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/****************************************************************************
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* Name: gpio_read
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*
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* Description:
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* Standard character driver read method.
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*
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****************************************************************************/
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static ssize_t gpio_read(FAR struct file *filep, FAR char *buffer,
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size_t buflen)
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{
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return 0;
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}
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/****************************************************************************
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* Name: gpio_write
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*
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* Description:
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* Standard character driver write method.
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*
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****************************************************************************/
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static ssize_t gpio_write(FAR struct file *filep, FAR const char *buffer,
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size_t buflen)
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{
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return (ssize_t)buflen;
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}
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/****************************************************************************
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* Name: gpio_ioctl
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*
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* Description:
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* Standard character driver ioctl method.
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*
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****************************************************************************/
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static int gpio_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
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{
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FAR struct inode *inode;
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FAR struct gpio_dev_s *dev;
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irqstate_t flags;
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pid_t pid;
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int ret;
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int i;
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int j;
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DEBUGASSERT(filep != NULL && filep->f_inode != NULL);
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inode = filep->f_inode;
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DEBUGASSERT(inode->i_private != NULL);
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dev = inode->i_private;
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switch (cmd)
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{
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/* Command: GPIOC_WRITE
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* Description: Set the value of an output GPIO
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* Argument: 0=output a low value; 1=outut a high value
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*/
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case GPIOC_WRITE:
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if (dev->gp_pintype == GPIO_OUTPUT_PIN)
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{
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DEBUGASSERT(arg == 0ul || arg == 1ul);
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ret = dev->gp_ops->go_write(dev, (bool)arg);
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}
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else
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{
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ret = -EACCES;
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}
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break;
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/* Command: GPIOC_READ
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* Description: Read the value of an input or output GPIO
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* Argument: A pointer to an bool value to receive the result:
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* false=low value; true=high value.
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*/
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case GPIOC_READ:
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{
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FAR bool *ptr = (FAR bool *)((uintptr_t)arg);
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DEBUGASSERT(ptr != NULL);
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ret = dev->gp_ops->go_read(dev, ptr);
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DEBUGASSERT(ret < 0 || *ptr == 0 || *ptr == 1);
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}
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break;
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/* Command: GPIOC_PINTYPE
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* Description: Return the GPIO pin type.
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* Argument: A pointer to an instance of type enum gpio_pintype_e
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*/
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case GPIOC_PINTYPE:
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{
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FAR enum gpio_pintype_e *ptr = (FAR enum gpio_pintype_e *)((uintptr_t)arg);
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DEBUGASSERT(ptr != NULL);
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*ptr = dev->gp_pintype;
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ret = OK;
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}
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break;
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/* Command: GPIOC_REGISTER
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* Description: Register to receive a signal whenever there an
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* interrupt is received on an input gpio pin. This
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* feature, of course, depends upon interrupt GPIO
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* support from the platform.
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* Argument: The number of signal to be generated when the
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* interrupt occurs.
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*/
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case GPIOC_REGISTER:
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if (arg && dev->gp_pintype == GPIO_INTERRUPT_PIN)
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{
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pid = getpid();
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flags = spin_lock_irqsave();
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for (i = 0; i < CONFIG_DEV_GPIO_NSIGNALS; i++)
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{
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FAR struct gpio_signal_s *signal = &dev->gp_signals[i];
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if (signal->gp_pid == 0 || signal->gp_pid == pid)
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{
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memcpy(&signal->gp_event, (FAR void *)arg,
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sizeof(signal->gp_event));
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signal->gp_pid = pid;
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ret = OK;
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break;
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}
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}
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spin_unlock_irqrestore(flags);
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if (i == 0)
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{
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/* Register our handler */
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ret = dev->gp_ops->go_attach(dev,
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(pin_interrupt_t)gpio_handler);
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if (ret >= 0)
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{
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/* Enable pin interrupts */
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ret = dev->gp_ops->go_enable(dev, true);
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}
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}
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else if (i == CONFIG_DEV_GPIO_NSIGNALS)
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{
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ret = -EBUSY;
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}
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}
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else
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{
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ret = -EACCES;
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}
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break;
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/* Command: GPIOC_UNREGISTER
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* Description: Stop receiving signals for pin interrupts.
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* Argument: None.
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*/
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case GPIOC_UNREGISTER:
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if (dev->gp_pintype == GPIO_INTERRUPT_PIN)
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{
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pid = getpid();
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flags = spin_lock_irqsave();
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for (i = 0; i < CONFIG_DEV_GPIO_NSIGNALS; i++)
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{
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if (pid == dev->gp_signals[i].gp_pid)
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{
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for (j = i + 1; j < CONFIG_DEV_GPIO_NSIGNALS; j++)
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{
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if (dev->gp_signals[j].gp_pid == 0)
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{
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break;
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}
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}
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if (i != --j)
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{
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memcpy(&dev->gp_signals[i], &dev->gp_signals[j],
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sizeof(dev->gp_signals[i]));
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}
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dev->gp_signals[j].gp_pid = 0;
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nxsig_cancel_notification(&dev->gp_signals[j].gp_work);
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ret = OK;
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break;
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}
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}
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spin_unlock_irqrestore(flags);
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if (i == 0 && j == 0)
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{
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/* Make sure that the pin interrupt is disabled */
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ret = dev->gp_ops->go_enable(dev, false);
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if (ret >= 0)
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{
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/* Detach the handler */
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ret = dev->gp_ops->go_attach(dev, NULL);
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}
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}
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else if (i == CONFIG_DEV_GPIO_NSIGNALS)
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{
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ret = -EINVAL;
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}
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}
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else
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{
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ret = -EACCES;
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}
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break;
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/* Command: GPIOC_SETPINTYPE
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* Description: Set the GPIO pin type.
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* Argument: The enum gpio_pintype_e type.
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*/
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case GPIOC_SETPINTYPE:
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{
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ret = dev->gp_ops->go_setpintype(dev, arg);
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}
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break;
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/* Unrecognized command */
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default:
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ret = -ENOTTY;
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break;
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}
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return ret;
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}
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: gpio_pin_register
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*
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* Description:
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* Register GPIO pin device driver.
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*
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* - Input pin types will be registered at /dev/gpinN
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* - Output pin types will be registered at /dev/gpoutN
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* - Interrupt pin types will be registered at /dev/gpintN
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*
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* Where N is the provided minor number in the range of 0-99.
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*
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****************************************************************************/
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int gpio_pin_register(FAR struct gpio_dev_s *dev, int minor)
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{
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FAR const char *fmt;
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char devname[16];
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int ret;
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DEBUGASSERT(dev != NULL && dev->gp_ops != NULL && (unsigned int)minor < 100);
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switch (dev->gp_pintype)
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{
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case GPIO_INPUT_PIN:
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{
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DEBUGASSERT(dev->gp_ops->go_read != NULL);
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fmt = "/dev/gpin%u";
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}
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break;
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case GPIO_OUTPUT_PIN:
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{
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DEBUGASSERT(dev->gp_ops->go_read != NULL &&
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dev->gp_ops->go_write != NULL);
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fmt = "/dev/gpout%u";
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}
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break;
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case GPIO_INTERRUPT_PIN:
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{
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DEBUGASSERT(dev->gp_ops->go_read != NULL &&
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dev->gp_ops->go_attach != NULL &&
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dev->gp_ops->go_enable != NULL);
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/* Make sure that the pin interrupt is disabled */
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ret = dev->gp_ops->go_enable(dev, false);
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if (ret < 0)
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{
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return ret;
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}
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fmt = "/dev/gpint%u";
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}
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break;
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default:
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return -EINVAL;
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}
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snprintf(devname, 16, fmt, (unsigned int)minor);
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gpioinfo("Registering %s\n", devname);
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return register_driver(devname, &g_gpio_drvrops, 0666, dev);
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}
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/****************************************************************************
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* Name: gpio_pin_unregister
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*
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* Description:
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* Unregister GPIO pin device driver.
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*
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* - Input pin types will be registered at /dev/gpinN
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* - Output pin types will be registered at /dev/gpoutN
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* - Interrupt pin types will be registered at /dev/gpintN
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*
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* Where N is the provided minor number in the range of 0-99.
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*
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*
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****************************************************************************/
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void gpio_pin_unregister(FAR struct gpio_dev_s *dev, int minor)
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{
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FAR const char *fmt;
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char devname[16];
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switch (dev->gp_pintype)
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{
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case GPIO_INPUT_PIN:
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{
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fmt = "/dev/gpin%u";
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}
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break;
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case GPIO_OUTPUT_PIN:
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{
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fmt = "/dev/gpout%u";
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}
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break;
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case GPIO_INTERRUPT_PIN:
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{
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fmt = "/dev/gpint%u";
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}
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break;
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default:
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return;
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}
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snprintf(devname, 16, fmt, (unsigned int)minor);
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gpioinfo("Unregistering %s\n", devname);
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(void)unregister_driver(devname);
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}
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#endif /* CONFIG_DEV_GPIO */
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