drivrs/ioexpander: Add support for a very simple GPIO drivers. It supports only pre-conrigured input and output pins and only basic input and output operations.

drivers/Kconfig

@@ -370,17 +370,7 @@ if INPUT
 source drivers/input/Kconfig
 endif # INPUT
 
-menuconfig IOEXPANDER
-	bool "IO Expander Support"
-	default n
-	---help---
-		This directory holds implementations of IO expander drivers.
-		See include/nuttx/ioexpander/ioexpander.h for registration information.
-
-if IOEXPANDER
 source drivers/ioexpander/Kconfig
-endif # IOEXPANDER
-
 source drivers/lcd/Kconfig
 source drivers/leds/Kconfig
 

drivers/ioexpander/Kconfig

@@ -3,6 +3,17 @@
 # see the file kconfig-language.txt in the NuttX tools repository.
 #
 
+menu "IO Expander/GPIO Support"
+
+config IOEXPANDER
+	bool "Enable IO Expander Support"
+	default n
+	---help---
+		This directory holds implementations of IO expander drivers.
+		See include/nuttx/ioexpander/ioexpander.h for registration information.
+
+if IOEXPANDER
+
 config IOEXPANDER_PCA9555
 	bool "PCA9555 I2C IO expander"
 	default n
@@ -40,3 +51,14 @@ config IOEXPANDER_MULTIPIN
 	---help---
 		This settings enable the definition of routines for
 		optimized simultaneous access to multiple pins.
+
+endif # IOEXPANDER
+
+config DEV_GPIO
+	bool "GPIO driver"
+	default n
+	---help---
+		Enables a simple GPIO input/output driver to support application-
+		space testing of hardware.
+
+endmenu # IO Expander/GPIO Support

drivers/ioexpander/Make.defs

@@ -43,6 +43,26 @@ ifeq ($(CONFIG_IOEXPANDER_PCA9555),y)
   CSRCS += pca9555.c
 endif
 
+endif # CONFIG_IOEXPANDER
+
+# GPIO test device driver (independent of IOEXPANDERS)
+
+ifeq ($(CONFIG_DEV_GPIO),y)
+  CSRCS += gpio.c
+endif
+
+# The folling implements an awkward OR
+
+ifeq ($(CONFIG_IOEXPANDER),y)
+
+# Include ioexpander I/O device driver build support
+
+DEPPATH += --dep-path ioexpander
+VPATH += :ioexpander
+CFLAGS += ${shell $(INCDIR) $(INCDIROPT) "$(CC)" $(TOPDIR)$(DELIM)drivers$(DELIM)ioexpander}
+
+else ifeq ($(CONFIG_DEV_GPIO),y)
+
 # Include ioexpander I/O device driver build support
 
 DEPPATH += --dep-path ioexpander

drivers/ioexpander/gpio.c

@@ -0,0 +1,269 @@
+/****************************************************************************
+ * 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 <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_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_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 =
+{
+  gpio_open,  /* open */
+  gpio_close, /* close */
+  NULL,       /* 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_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_common_dev_s *dev;
+  int ret = OK;
+
+  DEBUGASSERT(filep != NULL && filep->f_inode != NULL);
+  inode = filep->f_inode;
+  DEBUGASSERT(inode->i_private != NULL);
+  dev = inode->i_private;
+
+  switch (cmd)
+  {
+  /* Command:     GPIO_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->output)
+      {
+        FAR struct gpio_output_dev_s *outdev =
+          (FAR struct gpio_output_dev_s *)dev;
+
+        DEBUGASSERT(outdev->gpout_write != NULL);
+        ret = outdev->gpout_write(outdev, (int)arg);
+      }
+    else
+      {
+        ret = -EACCES;
+      }
+    break;
+
+  /* Command:     GPIO_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:
+    if (dev->output)
+      {
+        FAR struct gpio_output_dev_s *outdev =
+          (FAR struct gpio_output_dev_s *)dev;
+
+        DEBUGASSERT(outdev->gpout_read != NULL);
+        ret = outdev->gpout_read(outdev);
+      }
+    else
+      {
+        FAR struct gpio_input_dev_s *indev =
+          (FAR struct gpio_input_dev_s *)dev;
+
+        DEBUGASSERT(indev->gpin_read != NULL);
+        ret = indev->gpin_read(indev);
+      }
+    break;
+  }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: gpio_input_register
+ *
+ * Description:
+ *   Register GPIO input pin device driver.
+ *
+ ****************************************************************************/
+
+int gpio_input_register(FAR struct gpio_input_dev_s *dev, int minor)
+{
+  char devname[16];
+
+  DEBUGASSERT((unsigned int)minor < 100);
+  snprintf(devname, 16, "/dev/gpin%u", (unsigned int)minor);
+
+  return register_driver(devname, &g_gpio_input_ops, 0444, dev);
+}
+
+/****************************************************************************
+ * Name: gpio_output_register
+ *
+ * Description:
+ *   Register GPIO output pin device driver.
+ *
+ ****************************************************************************/
+
+int gpio_output_register(FAR struct gpio_output_dev_s *dev, int minor)
+{
+  char devname[16];
+
+  DEBUGASSERT((unsigned int)minor < 100);
+  snprintf(devname, 16, "/dev/gpout%u", (unsigned int)minor);
+
+  return register_driver(devname, &g_gpio_output_ops, 0222, dev);
+}
+
+#endif /* CONFIG_DEV_GPIO */

include/nuttx/fs/ioctl.h

@@ -83,6 +83,7 @@
 #define _LOOPBASE       (0x1e00) /* Loop device commands */
 #define _MODEMBASE      (0x1f00) /* Modem ioctl commands */
 #define _I2CBASE        (0x2000) /* I2C driver commands */
+#define _GPIOBASE       (0x2100) /* GPIO driver commands */
 
 /* boardctl commands share the same number space */
 
@@ -381,6 +382,11 @@
 #define _I2CIOCVALID(c)    (_IOC_TYPE(c)==_I2CBASE)
 #define _I2CIOC(nr)        _IOC(_I2CBASE,nr)
 
+/* GPIO driver command definitions ******************************************/
+
+#define _GPIOCVALID(c)     (_IOC_TYPE(c)==_GPIOBASE)
+#define _GPIOC(nr)         _IOC(_GPIOBASE,nr)
+
 /* boardctl() command definitions *******************************************/
 
 #define _BOARDIOCVALID(c) (_IOC_TYPE(c)==_BOARDBASE)

include/nuttx/ioexpander/gpio.h

@@ -0,0 +1,132 @@
+/********************************************************************************************
+ * include/nuttx/ioexpander/gpio.h
+ *
+ *   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.
+ *
+ ********************************************************************************************/
+
+#ifndef __INCLUDE_NUTTX_IOEXPANDER_GPIO_H
+#define __INCLUDE_NUTTX_IOEXPANDER_GPIO_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/fs/ioctl.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Command:     GPIO_WRITE
+ * Description: Set the value of an output GPIO
+ * Argument:    0=output a low value; 1=outut a high value
+ *
+ * Command:     GPIO_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.
+ */
+
+#define GPIO_WRITE _GPIOC(1)
+#define GPIO_READ  _GPIOC(2)
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/* Common interface definition.  Must be cast-compatible with struct
+ * gpio_input_dev_s and struct gpio_output_dev_s
+ */
+
+struct gpio_common_dev_s
+{
+  bool output;
+  uint8_t unused[3];
+};
+
+/* The interface to a GPIO input pin */
+
+struct gpio_input_dev_s
+{
+  bool output;
+  uint8_t unused[3];
+  CODE int (*gpin_read)(FAR struct gpio_input_dev_s *dev);
+};
+
+/* The interface to a GPIO input pin */
+
+struct gpio_output_dev_s
+{
+  bool output;
+  uint8_t unused[3];
+  CODE int (*gpout_read)(FAR struct gpio_output_dev_s *dev);
+  CODE int (*gpout_write)(FAR struct gpio_output_dev_s *dev, int value);
+};
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#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
+ *
+ * Description:
+ *   Register GPIO output pin device driver.
+ *
+ ****************************************************************************/
+
+int gpio_output_register(FAR struct gpio_output_dev_s *dev, int minor);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __INCLUDE_NUTTX_IOEXPANDER_GPIO_H */

include/nuttx/ioexpander/pca9555.h

@@ -1,4 +1,4 @@
-/********************************************************************************************
+/****************************************************************************
  * include/nuttx/ioexpander/pca9555.h
  *
  *   Copyright (C) 2015 Gregory Nutt. All rights reserved.
@@ -35,20 +35,31 @@
  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  *
- ********************************************************************************************/
+ ****************************************************************************/
 
 #ifndef __INCLUDE_NUTTX_IOEXPANDER_PCA9555_H
 #define __INCLUDE_NUTTX_IOEXPANDER_PCA9555_H
 
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
 #include <nuttx/i2c/i2c_master.h>
 
-/* A reference to a structure of this type must be passed to the PCA9555 driver when the
+/****************************************************************************
- * driver is instantiated. This structure provides information about the configuration of
+ * Public Types
- * the PCA9555 and provides some board-specific hooks.
+ ****************************************************************************/
+
+/* A reference to a structure of this type must be passed to the PCA9555
+ * driver when the driver is instantiated. This structure provides
+ * information about the configuration of the PCA9555 and provides some
+ * board-specific hooks.
  *
- * Memory for this structure is provided by the caller.  It is not copied by the driver
+ * Memory for this structure is provided by the caller.  It is not copied by
- * and is presumed to persist while the driver is active. The memory must be writeable
+ * the driver and is presumed to persist while the driver is active. The
- * because, under certain circumstances, the driver may modify the frequency.
+ * memory must be writeable because, under certain circumstances, the driver
+ * may modify the frequency.
  */
 
 struct pca9555_config_s
@@ -81,9 +92,9 @@ struct pca9555_config_s
 #endif
 };
 
-/********************************************************************************************
+/****************************************************************************
  * Public Function Prototypes
- ********************************************************************************************/
+ ****************************************************************************/
 
 #ifdef __cplusplus
 #define EXTERN extern "C"
@@ -93,11 +104,12 @@ extern "C"
 #define EXTERN extern
 #endif
 
-/********************************************************************************************
+/****************************************************************************
  * Name: pca9555_initialize
  *
  * Description:
- *   Instantiate and configure the PCA9555 device driver to use the provided I2C device 
+ *   Instantiate and configure the PCA9555 device driver to use the provided
+ *   I2C device
  *   instance.
  *
  * Input Parameters:
@@ -108,9 +120,9 @@ extern "C"
  * Returned Value:
  *   an ioexpander_dev_s instance on success, NULL on failure.
  *
- ********************************************************************************************/
+ ****************************************************************************/
 
-FAR struct ioexpander_dev_s* pca9555_initialize(FAR struct i2c_master_s *dev,
+FAR struct ioexpander_dev_s *pca9555_initialize(FAR struct i2c_master_s *dev,
                                                 FAR struct pca9555_config_s *config);
 
 #ifdef __cplusplus