/****************************************************************************
 * include/nuttx/input/ajoystick.h
 *
 *   Copyright (C) 2014 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.
 *
 ****************************************************************************/

/* This header file provides definition for a standard analog joystick
 * interface.  An analog joystick refers to a joystick that provides X/Y
 * positional data as integer values such as might be provides by Analog-
 * to-Digital Conversion (ADC).  The analog positional data may also be
 * accompanied by discrete button data.
 *
 * The analog joystick driver exports a standard character driver
 * interface. By convention, the analog joystick is registered as an input
 * device at /dev/ajoyN where N uniquely identifies the driver instance.
 *
 * This header file documents the generic interface that all NuttX analog
 * joystick devices must conform.  It adds standards and conventions on top
 * of the standard character driver interface.
 */

#ifndef __INCLUDE_NUTTX_INPUT_AJOYSTICK_H
#define __INCLUDE_NUTTX_INPUT_AJOYSTICK_H

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>
#include <nuttx/fs/ioctl.h>

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/
/* Configuration ************************************************************/

#ifndef CONFIG_AJOYSTICK_NPOLLWAITERS
#  define CONFIG_AJOYSTICK_NPOLLWAITERS 2
#endif

/* Joystick Interface *******************************************************/
/* These definitions provide the meaning of all of the bits that may be
 * reported in the ajoy_buttonset_t bitset.
 */

#define AJOY_BUTTON(n)       ((n)-1)              /* Bit n-1: Button n, n=1..8 */
#define AJOY_BUTTON_1        (0)                  /* Bit 0: Button 1 */
#define AJOY_BUTTON_2        (1)                  /* Bit 1: Button 2 */
#define AJOY_BUTTON_3        (2)                  /* Bit 2: Button 3 */
#define AJOY_BUTTON_4        (3)                  /* Bit 3: Button 4 */
#define AJOY_BUTTON_5        (4)                  /* Bit 4: Button 5 */
#define AJOY_BUTTON_6        (5)                  /* Bit 5: Button 6 */
#define AJOY_BUTTON_7        (6)                  /* Bit 6: Button 7 */
#define AJOY_BUTTON_8        (7)                  /* Bit 7: Button 8 */
#define AJOY_NBUTTONS        (8)                  /* Total number of buttons */

#define AJOY_BUTTON_1_BIT    (1 << AJOY_BUTTON_1) /* 1:Button 1 pressed */
#define AJOY_BUTTON_2_BIT    (1 << AJOY_BUTTON_2) /* 1:Button 2 pressed */
#define AJOY_BUTTON_3_BIT    (1 << AJOY_BUTTON_3) /* 1:Button 3 pressed */
#define AJOY_BUTTON_4_BIT    (1 << AJOY_BUTTON_4) /* 1:Button 4 pressed */
#define AJOY_BUTTON_5_BIT    (1 << AJOY_BUTTON_5) /* 1:Button 5 pressed */
#define AJOY_BUTTON_6_BIT    (1 << AJOY_BUTTON_6) /* 1:Button 6 pressed */
#define AJOY_BUTTON_7_BIT    (1 << AJOY_BUTTON_7) /* 1:Button 7 pressed */
#define AJOY_BUTTON_8_BIT    (1 << AJOY_BUTTON_8) /* 1:Button 8 pressed */
#define AJOY_BUTTONS_ALL     0xff                 /* Set of all buttons */

/* Typical usage */

#define AJOY_BUTTON_SELECT     AJOY_BUTTON_1
#define AJOY_BUTTON_FIRE       AJOY_BUTTON_2
#define AJOY_BUTTON_JUMP       AJOY_BUTTON_3

#define AJOY_BUTTON_SELECT_BIT AJOY_BUTTON_1_BIT
#define AJOY_BUTTON_FIRE_BIT   AJOY_BUTTON_2_BIT
#define AJOY_BUTTON_JUMP_BIT   AJOY_BUTTON_3_BIT

/* IOCTL commands
 *
 * Discrete joystick drivers do not support the character driver write() or
 * seek() methods.  The remaining driver methods behave as follows:
 *
 * 1) The read() method will always return a single value of size
 *    struct ajoy_sample_s represent the current joystick positional and the
 *    state of all joystick buttons. read() never blocks.  X an Y position
 *    data is raw converted data.  Zeroing and scaling must be performed by
 *    the application.
 * 2) The poll() method can be used to notify a client if there is a change
 *    in any of the joystick button inputs.  This feature, of course,
 *    depends upon interrupt GPIO support from the platform.  NOTE: that
 *    semantics of poll() for POLLIN are atypical:  The successful poll
 *    means that the button data has changed and has nothing to with the
 *    availability of data to be read; data is always available to be
 *    read.
 * 3) The ioctl() method supports the commands documented below:
 */

/* Command:     AJOYIOC_SUPPORTED
 * Description: Report the set of button events supported by the hardware;
 * Argument:    A pointer to writeable integer value in which to return the
 *              set of supported buttons.
 * Return:      Zero (OK) on success.  Minus one will be returned on failure
 *              with the errno value set appropriately.
 */

#define AJOYIOC_SUPPORTED  _AJOYIOC(0x0001)

/* Command:     AJOYIOC_POLLEVENTS
 * Description: Specify the set of button events that can cause a poll()
 *              to awaken.  The default is all button depressions and all
 *              button releases (all supported buttons);
 * Argument:    A read-only pointer to an instance of struct ajoy_pollevents_s
 * Return:      Zero (OK) on success.  Minus one will be returned on failure
 *              with the errno value set appropriately.
 */

#define AJOYIOC_POLLEVENTS  _AJOYIOC(0x0002)

/* Command:     AJOYIOC_REGISTER
 * Description: Register to receive a signal whenever there is a change in
 *              any of the joystick analog inputs.  This feature, of
 *              course, depends upon interrupt GPIO support from the
 *              platform.
 * Argument:    A read-only pointer to an instance of struct ajoy_notify_s
 * Return:      Zero (OK) on success.  Minus one will be returned on failure
 *              with the errno value set appropriately.
 */

#define AJOYIOC_REGISTER   _AJOYIOC(0x0003)

/****************************************************************************
 * Public Types
 ****************************************************************************/
/* This type is a bit set that contains the state of all analog joystick
 * buttons.
 */

typedef uint8_t ajoy_buttonset_t;

/* A reference to this structure is provided with the AJOYIOC_POLLEVENTS IOCTL
 * command and describes the conditions under which the client would like
 * to receive notification.
 */

struct ajoy_pollevents_s
{
  ajoy_buttonset_t ap_press;   /* Set of button depressions to wake up the poll */
  ajoy_buttonset_t ap_release; /* Set of button releases to wake up the poll */
};

/* A reference to this structure is provided with the AJOYIOC_REGISTER IOCTL
 * command and describes the conditions under which the client would like
 * to receive notification.
 */

struct ajoy_notify_s
{
  ajoy_buttonset_t an_press;   /* Set of button depressions to be notified */
  ajoy_buttonset_t an_release; /* Set of button releases to be notified */
  uint8_t          an_signo;   /* Signal number to use in the notification */
};

/* This structure is returned by read() and provides the sample state of the
 * analog joystick.
 *
 * NOTE: that this structure is equivalent to the struct mouse_report_s
 * structure (with no wheel) defined in include/nuttx/input/mouse.h and can
 * be used interchangeably in certain contexts.
 */

struct ajoy_sample_s
{
  ajoy_buttonset_t as_buttons; /* State of all buttons */
                               /* Possibly padded with 1 byte here */
  int16_t          as_x;       /* X/horizontal position */
  int16_t          as_y;       /* Y/vertical position */
};

/* This is the type of the analog joystick interrupt handler used with
 * the struct ajoy_lowerhalf_s enable() method.
 */

struct ajoy_lowerhalf_s;
typedef CODE void (*ajoy_handler_t)
  (FAR const struct ajoy_lowerhalf_s *lower, FAR void *arg);

/* The analog joystick driver is a two-part driver:
 *
 * 1) A common upper half driver that provides the common user interface to
 *    the joystick,
 * 2) Platform-specific lower half drivers that provide the interface
 *    between the common upper half and the platform analog and discrete
 *    inputs.
 *
 * This structure defines the interface between an instance of the lower
 * half driver and the common upper half driver.  Such an instance is
 * passed to the upper half driver when the driver is initialized, binding
 * the upper and lower halves into one driver.
 */

struct ajoy_lowerhalf_s
{
  /* Return the set of buttons supported on the analog joystick device */

  CODE ajoy_buttonset_t (*al_supported)(FAR const struct ajoy_lowerhalf_s *lower);

  /* Return the current state of all analog joystick position and button data */

  CODE int (*al_sample)(FAR const struct ajoy_lowerhalf_s *lower,
                        FAR struct ajoy_sample_s *sample);

  /* Return the current state of button data (only) */

  CODE ajoy_buttonset_t (*al_buttons)(FAR const struct ajoy_lowerhalf_s *lower);

  /* Enable interrupts on the selected set of joystick buttons.  An empty
   * set will disable all interrupts.
   */

  CODE void (*al_enable)(FAR const struct ajoy_lowerhalf_s *lower,
                         ajoy_buttonset_t press, ajoy_buttonset_t release,
                         ajoy_handler_t handler, FAR void *arg);
};

/****************************************************************************
 * Public Data
 ****************************************************************************/

#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif

/****************************************************************************
 * Public Function Prototypes
 ****************************************************************************/

/****************************************************************************
 * Name: ajoy_register
 *
 * Description:
 *   Bind the lower half analog joystick driver to an instance of the upper
 *   half analog joystick driver and register the composite character
 *   driver as the specified device.
 *
 * Input Parameters:
 *   devname - The name of the analog joystick device to be registers.
 *     This should be a string of the form "/dev/ajoyN" where N is the the
 *     minor device number.
 *   lower - An instance of the platform-specific analog joystick lower
 *     half driver.
 *
 * Returned Values:
 *   Zero (OK) is returned on success.  Otherwise a negated errno value is
 *   returned to indicate the nature of the failure.
 *
 ****************************************************************************/

int ajoy_register(FAR const char *devname,
                  FAR const struct ajoy_lowerhalf_s *lower);

#undef EXTERN
#ifdef __cplusplus
}
#endif

#endif /* __INCLUDE_NUTTX_INPUT_AJOYSTICK_H */
