PortIn.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #ifndef MBED_PORTIN_H
00017 #define MBED_PORTIN_H
00018 
00019 #include "platform/platform.h"
00020 
00021 #if defined (DEVICE_PORTIN) || defined(DOXYGEN_ONLY)
00022 
00023 #include "hal/port_api.h"
00024 #include "platform/mbed_critical.h"
00025 
00026 namespace mbed {
00027 /** \addtogroup drivers */
00028 
00029 /** A multiple pin digital input
00030  *
00031  * @note Synchronization level: Interrupt safe
00032  *
00033  *  Example:
00034  * @code
00035  * // Turn on an LED if any pins of Port2[0:5] are high
00036  *
00037  * #include "mbed.h"
00038  *
00039  * PortIn     p(Port2, 0x0000003F);  // Port2 pins [0:5] only
00040  * DigitalOut led(LED4);
00041  *
00042  * int main() {
00043  *     while(1) {
00044  *         int pins = p.read();
00045  *         if(pins) {
00046  *             led = 1;
00047  *         } else {
00048  *             led = 0;
00049  *         }
00050  *     }
00051  * }
00052  * @endcode
00053  * @ingroup drivers
00054  */
00055 class PortIn {
00056 public:
00057 
00058     /** Create a PortIn, connected to the specified port
00059      *
00060      *  @param port Port to connect to (as defined in target's PortNames.h)
00061      *  @param mask Bitmask defines which port pins should be an input (0 - ignore, 1 - include)
00062         */
00063     PortIn(PortName port, int mask = 0xFFFFFFFF)
00064     {
00065         core_util_critical_section_enter();
00066         port_init(&_port, port, mask, PIN_INPUT);
00067         core_util_critical_section_exit();
00068     }
00069 
00070     /** Read the value input to the port
00071      *
00072      *  @returns
00073      *    An integer with each bit corresponding to the associated pin value
00074      */
00075     int read()
00076     {
00077         return port_read(&_port);
00078     }
00079 
00080     /** Set the input pin mode
00081      *
00082      *  @param mode PullUp, PullDown, PullNone, OpenDrain
00083      */
00084     void mode(PinMode mode)
00085     {
00086         core_util_critical_section_enter();
00087         port_mode(&_port, mode);
00088         core_util_critical_section_exit();
00089     }
00090 
00091     /** A shorthand for read()
00092      */
00093     operator int()
00094     {
00095         return read();
00096     }
00097 
00098 private:
00099     port_t _port;
00100 };
00101 
00102 } // namespace mbed
00103 
00104 #endif
00105 
00106 #endif