/**************************************************************************** * 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 #include #include /**************************************************************************** * 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); /* Key write callback function */ CODE ssize_t (*bl_write)(FAR const struct btn_lowerhalf_s *lower, FAR const char *buffer, size_t buflen); }; /**************************************************************************** * 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 */