5f9ee79298
PCA9555 Driver: Replace the signalling logic with a simple callback using the new definitons of ioexpander.h. This repartitioning of functionality is necessary because (1) the I/O expander driver is the lower-lower part of any driver that uses GPIOs (include the GPIO driver itself) and should not be interacting directly with the much higher level application layer. And (2) in order to be compatible with the GPIO driver (and any arbitrary upper half driver), the PCA9555 should not directly signal, but should call back into the upper half. The upper half driver that interacts directly with the application is the appropriate place to be generating signal.
337 lines
9.9 KiB
C
337 lines
9.9 KiB
C
/****************************************************************************
|
|
* drivers/ioexpander/gpio.c
|
|
*
|
|
* Copyright (C) 2016 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 <nuttx/config.h>
|
|
|
|
#include <sys/types.h>
|
|
#include <stdio.h>
|
|
#include <signal.h>
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
|
|
#include <nuttx/fs/fs.h>
|
|
#include <nuttx/ioexpander/gpio.h>
|
|
|
|
#ifdef CONFIG_DEV_GPIO
|
|
|
|
/****************************************************************************
|
|
* Private Function Prototypes
|
|
****************************************************************************/
|
|
|
|
static int gpio_handler(FAR struct gpio_dev_s *dev);
|
|
static int gpio_open(FAR struct file *filep);
|
|
static int gpio_close(FAR struct file *filep);
|
|
static ssize_t gpio_read(FAR struct file *filep, FAR char *buffer,
|
|
size_t buflen);
|
|
static ssize_t gpio_write(FAR struct file *filep, FAR const char *buffer,
|
|
size_t buflen);
|
|
static int gpio_ioctl(FAR struct file *filep, int cmd,
|
|
unsigned long arg);
|
|
|
|
/****************************************************************************
|
|
* Private Data
|
|
****************************************************************************/
|
|
|
|
static const struct file_operations g_gpio_drvrops =
|
|
{
|
|
gpio_open, /* open */
|
|
gpio_close, /* close */
|
|
gpio_read, /* read */
|
|
gpio_write, /* write */
|
|
NULL, /* seek */
|
|
gpio_ioctl /* ioctl */
|
|
#ifndef CONFIG_DISABLE_POLL
|
|
, NULL /* poll */
|
|
#endif
|
|
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
|
|
, NULL /* unlink */
|
|
#endif
|
|
};
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: gpio_handler
|
|
*
|
|
* Description:
|
|
* GPIO interrupt callback function.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static int gpio_handler(FAR struct gpio_dev_s *dev)
|
|
{
|
|
DEBUGASSERT(dev != NULL);
|
|
(void)kill(dev->gp_pid, dev->gp_signo);
|
|
return OK;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: gpio_open
|
|
*
|
|
* Description:
|
|
* Standard character driver open method.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static int gpio_open(FAR struct file *filep)
|
|
{
|
|
return OK;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: gpio_close
|
|
*
|
|
* Description:
|
|
* Standard character driver close method.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static int gpio_close(FAR struct file *filep)
|
|
{
|
|
return OK;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: gpio_read
|
|
*
|
|
* Description:
|
|
* Standard character driver read method.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static ssize_t gpio_read(FAR struct file *filep, FAR char *buffer,
|
|
size_t buflen)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: gpio_write
|
|
*
|
|
* Description:
|
|
* Standard character driver write method.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static ssize_t gpio_write(FAR struct file *filep, FAR const char *buffer,
|
|
size_t buflen)
|
|
{
|
|
return (ssize_t)buflen;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: gpio_ioctl
|
|
*
|
|
* Description:
|
|
* Standard character driver ioctl method.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static int gpio_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
|
|
{
|
|
FAR struct inode *inode;
|
|
FAR struct gpio_dev_s *dev;
|
|
int ret;
|
|
|
|
DEBUGASSERT(filep != NULL && filep->f_inode != NULL);
|
|
inode = filep->f_inode;
|
|
DEBUGASSERT(inode->i_private != NULL);
|
|
dev = inode->i_private;
|
|
|
|
switch (cmd)
|
|
{
|
|
/* Command: GPIOC_WRITE
|
|
* Description: Set the value of an output GPIO
|
|
* Argument: 0=output a low value; 1=outut a high value
|
|
*/
|
|
|
|
case GPIOC_WRITE:
|
|
if (dev->gp_pintype == GPIO_OUTPUT_PIN)
|
|
{
|
|
DEBUGASSERT(arg == 0ul || arg == 1ul);
|
|
ret = dev->gp_ops->go_write(dev, (int)arg);
|
|
}
|
|
else
|
|
{
|
|
ret = -EACCES;
|
|
}
|
|
break;
|
|
|
|
/* Command: GPIOC_READ
|
|
* Description: Read the value of an input or output GPIO
|
|
* Argument: A pointer to an integer value to receive the result:
|
|
* 0=low value; 1=high value.
|
|
*/
|
|
|
|
case GPIOC_READ:
|
|
{
|
|
FAR int *ptr = (FAR int *)((uintptr_t)arg);
|
|
DEBUGASSERT(ptr != NULL);
|
|
|
|
ret = dev->gp_ops->go_read(dev, ptr);
|
|
DEBUGASSERT(ret < 0 || *ptr == 0 || *ptr == 1);
|
|
}
|
|
break;
|
|
|
|
/* Command: GPIOC_REGISTER
|
|
* Description: Register to receive a signal whenever there an
|
|
* interrupt is received on an input gpio pin. This
|
|
* feature, of course, depends upon interrupt GPIO
|
|
* support from the platform.
|
|
* Argument: The number of signal to be generated when the
|
|
* interrupt occurs.
|
|
*/
|
|
|
|
case GPIOC_REGISTER:
|
|
if (dev->gp_pintype == GPIO_INTERRUPT_PIN)
|
|
{
|
|
/* Make sure that the pin interrupt is disabled */
|
|
|
|
ret = dev->gp_ops->go_enable(dev, false);
|
|
if (ret >= 0)
|
|
{
|
|
/* Save signal information */
|
|
|
|
DEBUGASSERT(GOOD_SIGNO(arg));
|
|
|
|
dev->gp_pid = getpid();
|
|
dev->gp_signo = (uint8_t)arg;
|
|
|
|
/* Register our handler */
|
|
|
|
ret = dev->gp_ops->go_attach(dev,
|
|
(pin_interrupt_t)gpio_handler);
|
|
if (ret >= 0)
|
|
{
|
|
/* Enable pin interrupts */
|
|
|
|
ret = dev->gp_ops->go_enable(dev, true);
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
ret = -EACCES;
|
|
}
|
|
break;
|
|
|
|
/* Unrecognized command */
|
|
|
|
default:
|
|
ret = -ENOTTY;
|
|
break;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: gpio_pin_register
|
|
*
|
|
* Description:
|
|
* Register GPIO pin device driver.
|
|
*
|
|
* - Input pin types will be registered at /dev/gpinN
|
|
* - Output pin types will be registered at /dev/gpoutN
|
|
* - Interrupt pin types will be registered at /dev/gpintN
|
|
*
|
|
* Where N is the provided minor number in the range of 0-99.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int gpio_pin_register(FAR struct gpio_dev_s *dev, int minor)
|
|
{
|
|
FAR const char *fmt;
|
|
char devname[16];
|
|
int ret;
|
|
|
|
DEBUGASSERT(dev != NULL && dev->gp_ops != NULL && (unsigned int)minor < 100);
|
|
|
|
switch (dev->gp_pintype)
|
|
{
|
|
case GPIO_INPUT_PIN:
|
|
{
|
|
DEBUGASSERT(dev->gp_ops->go_read != NULL);
|
|
fmt = "/dev/gpin%u";
|
|
}
|
|
break;
|
|
|
|
case GPIO_OUTPUT_PIN:
|
|
{
|
|
DEBUGASSERT(dev->gp_ops->go_read != NULL &&
|
|
dev->gp_ops->go_write != NULL);
|
|
fmt = "/dev/gpout%u";
|
|
|
|
}
|
|
break;
|
|
|
|
case GPIO_INTERRUPT_PIN:
|
|
{
|
|
DEBUGASSERT(dev->gp_ops->go_read != NULL &&
|
|
dev->gp_ops->go_attach != NULL &&
|
|
dev->gp_ops->go_enable != NULL);
|
|
|
|
/* Make sure that the pin interrupt is disabled */
|
|
|
|
ret = dev->gp_ops->go_enable(dev, false);
|
|
if (ret < 0)
|
|
{
|
|
return ret;
|
|
}
|
|
|
|
fmt = "/dev/gpint%u";
|
|
}
|
|
break;
|
|
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
snprintf(devname, 16, fmt, (unsigned int)minor);
|
|
return register_driver(devname, &g_gpio_drvrops, 0666, dev);
|
|
}
|
|
|
|
#endif /* CONFIG_DEV_GPIO */
|