108 lines
3.4 KiB
C
108 lines
3.4 KiB
C
/*
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* Copyright (C) 2016 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef SYSTEM_PERIPHERALMANAGER_GPIO_H_
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#define SYSTEM_PERIPHERALMANAGER_GPIO_H_
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#include <sys/cdefs.h>
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#include <sys/types.h>
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__BEGIN_DECLS
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/// @defgroup Gpio Gpio Interface
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/// @brief Functions to control GPIO pins.
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///
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/// These functions can be used to control GPIO.
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/// @{
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/// Edge trigger types.
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enum {
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NONE_EDGE, /**< None */
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RISING_EDGE, /**< Rising edge */
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FALLING_EDGE, /**< Falling edge */
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BOTH_EDGE /**< Both edges */
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};
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/// GPIO direction types.
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enum {
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DIRECTION_IN, /**< Input mode */
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DIRECTION_OUT_INITIALLY_HIGH, /**< Output mode, initially set to high */
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DIRECTION_OUT_INITIALLY_LOW /**< Output mode, initially set to low */
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};
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/// Possible active types.
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enum {
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ACTIVE_LOW, /**< Active Low */
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ACTIVE_HIGH /**< Active High */
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};
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typedef struct BGpio BGpio;
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/// Sets the GPIO direction to output.
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/// @param gpio Pointer to the BGpio struct
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/// @param direction One of DIRECTION_IN,
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/// DIRECTION_OUT_INITIALLY_HIGH, DIRECTION_OUT_INITIALLY_LOW.
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/// @return 0 on success, errno on error.
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int BGpio_setDirection(const BGpio* gpio, int direction);
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/// Sets the interrupt edge trigger type.
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/// @param gpio Pointer to the BGpio struct
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/// @param type One of NONE_EDGE, RISING_EDGE, FALLING_EDGE or BOTH_EDGE.
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/// @return 0 on success, errno on error.
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int BGpio_setEdgeTriggerType(const BGpio* gpio, int type);
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/// Sets the GPIO’s active low/high status.
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/// @param gpio Pointer to the BGpio struct.
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/// @param type One of ACTIVE_HIGH, ACTIVE_LOW.
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/// @return 0 on success, errno on error.
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int BGpio_setActiveType(const BGpio* gpio, int type);
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/// Sets the GPIO value (for output GPIO only).
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/// @param gpio Pointer to the BGpio struct.
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/// @param value Value to set.
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/// @return 0 on success, errno on error.
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int BGpio_setValue(const BGpio* gpio, int value);
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/// Gets the GPIO value (for input GPIO only).
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/// @param gpio Pointer to the BGpio struct.
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/// @param value Output pointer to the value of the GPIO.
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/// @return 0 on success, errno on error.
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int BGpio_getValue(const BGpio* gpio, int* value);
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/// Returns a file descriptor that can be used to poll on new data.
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/// Can be passed to select/epoll to wait for data to become available.
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/// @param gpio Pointer to the BGpio struct.
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/// @param fd Output pointer to the file descriptor number.
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/// @return 0 on success, errno on error.
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int BGpio_getPollingFd(const BGpio* gpio, int* fd);
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/// Acknowledges the interrupt and resets the file descriptor.
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/// This must be called after each event triggers in order to be able to
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/// poll/select for another event.
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/// @param fd Polling file descriptor to reset.
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/// @return 0 on success, errno on error.
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int BGpio_ackInterruptEvent(int fd);
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/// Destroys a BGpio struct.
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/// @param gpio Pointer to the BGpio struct.
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void BGpio_delete(BGpio* gpio);
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/// @}
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__END_DECLS
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#endif // SYSTEM_PERIPHERALMANAGER_GPIO_H_
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