incubator-nuttx/include/nuttx/input/buttons.h

211 lines
7.5 KiB
C

/****************************************************************************
* include/nuttx/input/buttons.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_INPUT_BUTTONS_H
#define __INCLUDE_NUTTX_INPUT_BUTTONS_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/fs/ioctl.h>
#include <signal.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
#ifndef CONFIG_INPUT_BUTTONS_NPOLLWAITERS
# define CONFIG_INPUT_BUTTONS_NPOLLWAITERS 2
#endif
/* ioctl commands */
/* Command: BTNIOC_SUPPORTED
* Description: Report the set of button events supported by the hardware;
* Argument: A pointer to writeable btn_buttonset_t 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 BTNIOC_SUPPORTED _BTNIOC(0x0001)
/* Command: BTNIOC_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 btn_pollevents_s
* Return: Zero (OK) on success. Minus one will be returned on failure
* with the errno value set appropriately.
*/
#define BTNIOC_POLLEVENTS _BTNIOC(0x0002)
/* Command: BTNIOC_REGISTER
* Description: Register to receive a signal whenever there is a change in
* the state of button inputs. This feature, of course, depends
* upon interrupt GPIO support from the platform.
* Argument: A read-only pointer to an instance of struct btn_notify_s
* Return: Zero (OK) on success. Minus one will be returned on failure
* with the errno value set appropriately.
*/
#define BTNIOC_REGISTER _BTNIOC(0x0003)
/****************************************************************************
* Public Types
****************************************************************************/
/* This type is a bit set that contains the state of all buttons as defined
* in arch/board/board.h. This is the value that is returned when reading
* from the button driver.
*/
typedef uint32_t btn_buttonset_t;
/* A reference to this structure is provided with the BTNIOC_POLLEVENTS IOCTL
* command and describes the conditions under which the client would like
* to receive notification.
*/
struct btn_pollevents_s
{
btn_buttonset_t bp_press; /* Set of button depressions to wake up the poll */
btn_buttonset_t bp_release; /* Set of button releases to wake up the poll */
};
/* A reference to this structure is provided with the BTNIOC_REGISTER IOCTL
* command and describes the conditions under which the client would like
* to receive notification.
*/
struct btn_notify_s
{
btn_buttonset_t bn_press; /* Set of button depressions to be notified */
btn_buttonset_t bn_release; /* Set of button releases to be notified */
struct sigevent bn_event; /* Describe the way a task is to be notified */
};
/* This is the type of the button interrupt handler used with the struct
* btn_lowerhalf_s enable() method.
*/
struct btn_lowerhalf_s;
typedef CODE void (*btn_handler_t)
(FAR const struct btn_lowerhalf_s *lower, FAR void *arg);
/* The button driver is a two-part driver:
*
* 1) A common upper half driver that provides the common user interface to
* the buttons,
* 2) Platform-specific lower half drivers that provide the interface
* between the common upper half and the platform discrete button 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 btn_lowerhalf_s
{
/* Return the set of buttons supported by the board */
CODE btn_buttonset_t (*bl_supported)
(FAR const struct btn_lowerhalf_s *lower);
/* Return the current state of button data (only) */
CODE btn_buttonset_t (*bl_buttons)
(FAR const struct btn_lowerhalf_s *lower);
/* Enable interrupts on the selected set of buttons. An empty set will
* disable all interrupts.
*/
CODE void (*bl_enable)(FAR const struct btn_lowerhalf_s *lower,
btn_buttonset_t press, btn_buttonset_t release,
btn_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: btn_register
*
* Description:
* Bind the lower half button driver to an instance of the upper half
* button driver and register the composite character driver as the
* specified device.
*
* Input Parameters:
* devname - The name of the button device to be registered.
* This should be a string of the form "/dev/btnN" where N is the
* minor device number.
* lower - An instance of the platform-specific button lower half driver.
*
* Returned Value:
* Zero (OK) is returned on success. Otherwise a negated errno value is
* returned to indicate the nature of the failure.
*
****************************************************************************/
int btn_register(FAR const char *devname,
FAR const struct btn_lowerhalf_s *lower);
/****************************************************************************
* Name: btn_lower_initialize
*
* Description:
* Initialize the generic button lower half driver, bind it and register
* it with the upper half button driver as devname.
*
****************************************************************************/
#if CONFIG_INPUT_BUTTONS_LOWER
int btn_lower_initialize(FAR const char *devname);
#endif
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* __INCLUDE_NUTTX_INPUT_BUTTONS_H */