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Commit a932578e authored by Gregory Nutt's avatar Gregory Nutt
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GPIO driver: Add support for receiving signals from interrupt pins.

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drivers/ioexpander/gpio.c
+ 112
− 67
View file @ a932578e
......@@ -41,6 +41,7 @@
#include <sys/types.h>
#include <stdio.h>
#include <signal.h>
#include <assert.h>
#include <errno.h>
......@@ -53,6 +54,7 @@
* 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,
......@@ -66,23 +68,7 @@ static int gpio_ioctl(FAR struct file *filep, int cmd,
* Private Data
****************************************************************************/
static const struct file_operations g_gpio_input_ops =
{
gpio_open, /* open */
gpio_close, /* close */
gpio_read, /* read */
NULL, /* write */
NULL, /* seek */
gpio_ioctl /* ioctl */
#ifndef CONFIG_DISABLE_POLL
, NULL /* poll */
#endif
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
, NULL /* unlink */
#endif
};
static const struct file_operations g_gpio_output_ops =
static const struct file_operations g_gpio_drvrops =
{
gpio_open, /* open */
gpio_close, /* close */
......@@ -102,6 +88,21 @@ static const struct file_operations g_gpio_output_ops =
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: gpio_handler
*
* Description:
* Standard character driver open method.
*
****************************************************************************/
static int gpio_handler(FAR struct gpio_dev_s *dev)
{
DEBUGASSERT(dev != NULL);
kill(dev->gp_pid, dev->gp_signo);
return OK;
}
/****************************************************************************
* Name: gpio_open
*
......@@ -167,7 +168,7 @@ static ssize_t gpio_write(FAR struct file *filep, FAR const char *buffer,
static int gpio_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode;
FAR struct gpio_common_dev_s *dev;
FAR struct gpio_dev_s *dev;
int ret;
DEBUGASSERT(filep != NULL && filep->f_inode != NULL);
......@@ -177,20 +178,16 @@ static int gpio_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
switch (cmd)
{
/* Command: GPIO_WRITE
/* Command: GPIOC_WRITE
* Description: Set the value of an output GPIO
* Argument: 0=output a low value; 1=outut a high value
*/
case GPIO_WRITE:
if (dev->gp_output)
case GPIOC_WRITE:
if (dev->gp_pintype == GPIO_OUTPUT_PIN)
{
FAR struct gpio_output_dev_s *outdev =
(FAR struct gpio_output_dev_s *)dev;
DEBUGASSERT(outdev->gpout_write != NULL &&
((arg == 0UL) || (arg == 1UL)));
ret = outdev->gpout_write(outdev, (int)arg);
DEBUGASSERT(arg == 0ul || arg == 1ul);
ret = dev->gp_ops->go_write(dev, (int)arg);
}
else
{
......@@ -198,36 +195,62 @@ static int gpio_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
}
break;
/* Command: GPIO_READ
/* 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 GPIO_READ:
case GPIOC_READ:
{
FAR int *ptr = (FAR int *)((uintptr_t)arg);
DEBUGASSERT(ptr != NULL);
if (dev->gp_output)
{
FAR struct gpio_output_dev_s *outdev =
(FAR struct gpio_output_dev_s *)dev;
ret = dev->gp_ops->go_read(dev, ptr);
DEBUGASSERT(ret < 0 || *ptr == 0 || *ptr == 1);
}
break;
DEBUGASSERT(outdev->gpout_read != NULL);
ret = outdev->gpout_read(outdev, ptr);
}
else
{
FAR struct gpio_input_dev_s *indev =
(FAR struct gpio_input_dev_s *)dev;
/* 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.
*/
DEBUGASSERT(indev->gpin_read != NULL);
ret = indev->gpin_read(indev, ptr);
}
case GPIOC_REGISTER:
if (dev->gp_pintype == GPIO_INTERRUPT_PIN)
{
/* Make sure that the pin interrupt is disabled */
DEBUGASSERT(ret < 0 || *ptr == 0 || *ptr == 1);
}
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 */
......@@ -245,41 +268,63 @@ static int gpio_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
****************************************************************************/
/****************************************************************************
* Name: gpio_input_register
* Name: gpio_pin_register
*
* Description:
* Register GPIO input pin device driver.
* Register GPIO pin device driver.
*
****************************************************************************/
int gpio_input_register(FAR struct gpio_input_dev_s *dev, int minor)
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->gpin_output && dev->gpin_read != NULL &&
(unsigned int)minor < 100);
DEBUGASSERT(dev != NULL && dev->gp_ops != NULL && (unsigned int)minor < 100);
snprintf(devname, 16, "/dev/gpin%u", (unsigned int)minor);
return register_driver(devname, &g_gpio_input_ops, 0444, dev);
}
switch (dev->gp_pintype)
{
case GPIO_INPUT_PIN:
{
DEBUGASSERT(dev->gp_ops->go_read != NULL);
fmt = "/dev/gpin%u";
}
break;
/****************************************************************************
* Name: gpio_output_register
*
* Description:
* Register GPIO output pin device driver.
*
****************************************************************************/
case GPIO_OUTPUT_PIN:
{
DEBUGASSERT(dev->gp_ops->go_read != NULL &&
dev->gp_ops->go_write != NULL);
fmt = "/dev/gpout%u";
}
break;
int gpio_output_register(FAR struct gpio_output_dev_s *dev, int minor)
{
char devname[16];
case GPIO_INTERRUPT_PIN:
{
DEBUGASSERT(dev->gp_ops->go_read != NULL &&
dev->gp_ops->go_attach != NULL &&
dev->gp_ops->go_enable != NULL);
DEBUGASSERT(dev != NULL && dev->gpout_output && dev->gpout_read != NULL &&
dev->gpout_write != NULL &&(unsigned int)minor < 100);
/* 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, "/dev/gpout%u", (unsigned int)minor);
return register_driver(devname, &g_gpio_output_ops, 0222, dev);
snprintf(devname, 16, fmt, (unsigned int)minor);
return register_driver(devname, &g_gpio_drvrops, 0666, dev);
}
#endif /* CONFIG_DEV_GPIO */
include/nuttx/ioexpander/gpio.h
+ 48
− 42
View file @ a932578e
......@@ -47,64 +47,80 @@
* Pre-processor Definitions
****************************************************************************/
/* Command: GPIO_WRITE
/* Command: GPIOC_WRITE
* Description: Set the value of an output GPIO
* Argument: 0=output a low value; 1=outut a high value
*
* Command: GPIO_READ
* 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.
*
* 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.
*/
#define GPIO_WRITE _GPIOC(1)
#define GPIO_READ _GPIOC(2)
#define GPIOC_WRITE _GPIOC(1)
#define GPIOC_READ _GPIOC(2)
#define GPIOC_REGISTER _GPIOC(3)
/****************************************************************************
* Public Types
****************************************************************************/
/* Common interface definition. Must be cast-compatible with struct
* gpio_input_dev_s and struct gpio_output_dev_s
*/
/* Identifies the type of the GPIO pin */
struct gpio_common_dev_s
enum gpio_pintype_e
{
bool gp_output;
uint8_t gp_unused[3];
GPIO_INPUT_PIN = 0,
GPIO_OUTPUT_PIN,
GPIO_INTERRUPT_PIN
};
/* The interface to a GPIO input pin */
struct gpio_input_dev_s
{
/* Common fields */
/* Interrupt callback */
bool gpin_output;
uint8_t gpin_unused[3];
typedef CODE int (*pin_interrupt_t)(FAR struct gpio_dev_s *dev);
/* Fields unique to input pins */
/* Pin interface definition. */
CODE int (*gpin_read)(FAR struct gpio_input_dev_s *dev, FAR int *value);
struct gpio_dev_s;
struct gpio_operations_s
{
/* Interface methods */
/* Lower-half private definitions may follow */
CODE int (*go_read)(FAR struct gpio_dev_s *dev, FAR int *value);
CODE int (*go_write)(FAR struct gpio_dev_s *dev, int value);
CODE int (*go_attach)(FAR struct gpio_dev_s *dev,
pin_interrupt_t callback);
CODE int (*go_enable)(FAR struct gpio_dev_s *dev, bool enable);
};
/* The interface to a GPIO input pin */
/* Pin interface definition. */
struct gpio_output_dev_s
struct gpio_dev_s
{
/* Common fields */
/* Information provided from the lower half driver to the upper half
* driver when gpio_pin_register() is called.
*/
uint8_t gp_pintype; /* See enum gpio_pintype_e */;
/* Writable storage used by the upper half driver */
bool gpout_output;
uint8_t gpout_unused[3];
uint8_t gp_signo; /* signo to use when signaling a GPIO interrupt */
pid_t gp_pid; /* The task to be signalled */
/* Fields unique to output pins */
/* Read-only pointer to GPIO device operations (also provided by the
* lower half driver).
*/
CODE int (*gpout_read)(FAR struct gpio_output_dev_s *dev, FAR int *value);
CODE int (*gpout_write)(FAR struct gpio_output_dev_s *dev, int value);
FAR const struct gpio_operations_s *gp_ops;
/* Lower-half private definitions may follow */
/* Device specific information may follow */
};
/****************************************************************************
......@@ -120,24 +136,14 @@ extern "C"
#endif
/****************************************************************************
* Name: gpio_input_register
*
* Description:
* Register GPIO input pin device driver.
*
****************************************************************************/
int gpio_input_register(FAR struct gpio_input_dev_s *dev, int minor);
/****************************************************************************
* Name: gpio_output_register
* Name: gpio_pin_register
*
* Description:
* Register GPIO output pin device driver.
* Register GPIO pin device driver.
*
****************************************************************************/
int gpio_output_register(FAR struct gpio_output_dev_s *dev, int minor);
int gpio_pin_register(FAR struct gpio_dev_s *dev, int minor);
#ifdef __cplusplus
}
......
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