Mbed OS Reference | DigitalInOut.h Source File

 /* mbed Microcontroller Library
  * Copyright (c) 2006-2013 ARM Limited
  * SPDX-License-Identifier: Apache-2.0
  *
  * Licensed 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 MBED_DIGITALINOUT_H
 #define MBED_DIGITALINOUT_H
 
 #include "platform/platform.h"
 
 #include "hal/gpio_api.h"
 #include "platform/mbed_critical.h"
 
 namespace mbed {
 /** \addtogroup drivers */
 
 /** A digital input/output, used for setting or reading a bi-directional pin
  *
  * @note Synchronization level: Interrupt safe
  * @ingroup drivers
  */
 class DigitalInOut {
 
 public:
     /** Create a DigitalInOut connected to the specified pin
      *
      *  @param pin DigitalInOut pin to connect to
      */
     DigitalInOut(PinName pin) : gpio()
     {
         // No lock needed in the constructor
         gpio_init_in(&gpio, pin);
     }
 
     /** Create a DigitalInOut connected to the specified pin
      *
      *  @param pin DigitalInOut pin to connect to
      *  @param direction the initial direction of the pin
      *  @param mode the initial mode of the pin
      *  @param value the initial value of the pin if is an output
      */
     DigitalInOut(PinName pin, PinDirection direction, PinMode mode, int value) : gpio()
     {
         // No lock needed in the constructor
         gpio_init_inout(&gpio, pin, direction, mode, value);
     }
 
     /** Set the output, specified as 0 or 1 (int)
      *
      *  @param value An integer specifying the pin output value,
      *      0 for logical 0, 1 (or any other non-zero value) for logical 1
      */
     void write(int value)
     {
         // Thread safe / atomic HAL call
         gpio_write(&gpio, value);
     }
 
     /** Return the output setting, represented as 0 or 1 (int)
      *
      *  @returns
      *    an integer representing the output setting of the pin if it is an output,
      *    or read the input if set as an input
      */
     int read()
     {
         // Thread safe / atomic HAL call
         return gpio_read(&gpio);
     }
 
     /** Set as an output
      */
     void output()
     {
         core_util_critical_section_enter();
         gpio_dir(&gpio, PIN_OUTPUT);
         core_util_critical_section_exit();
     }
 
     /** Set as an input
      */
     void input()
     {
         core_util_critical_section_enter();
         gpio_dir(&gpio, PIN_INPUT);
         core_util_critical_section_exit();
     }
 
     /** Set the input pin mode
      *
      *  @param pull PullUp, PullDown, PullNone, OpenDrain
      */
     void mode(PinMode pull)
     {
         core_util_critical_section_enter();
         gpio_mode(&gpio, pull);
         core_util_critical_section_exit();
     }
 
     /** Return the output setting, represented as 0 or 1 (int)
      *
      *  @returns
      *    Non zero value if pin is connected to uc GPIO
      *    0 if gpio object was initialized with NC
      */
     int is_connected()
     {
         // Thread safe / atomic HAL call
         return gpio_is_connected(&gpio);
     }
 
     /** A shorthand for write()
      * \sa DigitalInOut::write()
      * @code
      *      DigitalInOut  inout(PIN);
      *      DigitalIn     button(BUTTON1);
      *      inout.output();
      *
      *      inout = button;     // Equivalent to inout.write(button.read())
      * @endcode
      */
     DigitalInOut &operator= (int value)
     {
         // Underlying write is thread safe
         write(value);
         return *this;
     }
 
     /**A shorthand for write() using the assignment operator which copies the
      * state from the DigitalInOut argument.
      * \sa DigitalInOut::write()
      */
     DigitalInOut &operator= (DigitalInOut &rhs)
     {
         core_util_critical_section_enter();
         write(rhs.read());
         core_util_critical_section_exit();
         return *this;
     }
 
     /** A shorthand for read()
      * \sa DigitalInOut::read()
      * @code
      *      DigitalInOut inout(PIN);
      *      DigitalOut led(LED1);
      *
      *      inout.input();
      *      led = inout;   // Equivalent to led.write(inout.read())
      * @endcode
      */
     operator int()
     {
         // Underlying call is thread safe
         return read();
     }
 
 protected:
 #if !defined(DOXYGEN_ONLY)
     gpio_t gpio;
 #endif //!defined(DOXYGEN_ONLY)
 };
 
 } // namespace mbed
 
 #endif
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