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BusInOut.h
1 /* mbed Microcontroller Library
2  * Copyright (c) 2006-2013 ARM Limited
3  * SPDX-License-Identifier: Apache-2.0
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17 #ifndef MBED_BUSINOUT_H
18 #define MBED_BUSINOUT_H
19 
20 #include "drivers/DigitalInOut.h"
21 #include "platform/PlatformMutex.h"
22 #include "platform/NonCopyable.h"
23 
24 namespace mbed {
25 /**
26  * \defgroup drivers_BusInOut BusInOut class
27  * \ingroup drivers-public-api-gpio
28  * @{
29  */
30 
31 /** A digital input output bus, used for setting the state of a collection of pins.
32  * Implemented as an array of DigitalInOut pins, the bus can be constructed by any
33  * pins without restriction other than being capable of digital input or output
34  * capabilities
35  *
36  * @note Synchronization level: Thread safe
37  */
38 class BusInOut : private NonCopyable<BusInOut> {
39 
40 public:
41 
42  /** Create a BusInOut, connected to the specified pins
43  *
44  * @param p0 DigitalInOut pin to connect to bus bit
45  * @param p1 DigitalInOut pin to connect to bus bit
46  * @param p2 DigitalInOut pin to connect to bus bit
47  * @param p3 DigitalInOut pin to connect to bus bit
48  * @param p4 DigitalInOut pin to connect to bus bit
49  * @param p5 DigitalInOut pin to connect to bus bit
50  * @param p6 DigitalInOut pin to connect to bus bit
51  * @param p7 DigitalInOut pin to connect to bus bit
52  * @param p8 DigitalInOut pin to connect to bus bit
53  * @param p9 DigitalInOut pin to connect to bus bit
54  * @param p10 DigitalInOut pin to connect to bus bit
55  * @param p11 DigitalInOut pin to connect to bus bit
56  * @param p12 DigitalInOut pin to connect to bus bit
57  * @param p13 DigitalInOut pin to connect to bus bit
58  * @param p14 DigitalInOut pin to connect to bus bit
59  * @param p15 DigitalInOut pin to connect to bus bit
60  *
61  * @note
62  * It is only required to specify as many pin variables as is required
63  * for the bus; the rest will default to NC (not connected)
64  */
65  BusInOut(PinName p0, PinName p1 = NC, PinName p2 = NC, PinName p3 = NC,
66  PinName p4 = NC, PinName p5 = NC, PinName p6 = NC, PinName p7 = NC,
67  PinName p8 = NC, PinName p9 = NC, PinName p10 = NC, PinName p11 = NC,
68  PinName p12 = NC, PinName p13 = NC, PinName p14 = NC, PinName p15 = NC);
69 
70  /** Create a BusInOut, connected to the specified pins
71  *
72  * @param pins An array of pins (PinName) to construct a BusInOut from. The maximum
73  * number of pins in the array is 16 and any pins that are unspecified or are not to be
74  * connected must be specified as NC in the array that is passed in
75  */
76  BusInOut(PinName pins[16]);
77 
78  virtual ~BusInOut();
79 
80  /* Group: Access Methods */
81 
82  /** Write the value to the output bus
83  *
84  * @param value An integer specifying a bit to write for every corresponding DigitalInOut pin
85  */
86  void write(int value);
87 
88  /** Read the value currently output on the bus
89  *
90  * @returns
91  * An integer with each bit corresponding to associated DigitalInOut pin setting
92  */
93  int read();
94 
95  /** Set all the pins in bus as output
96  */
97  void output();
98 
99  /** Set all the pins in bus as an input
100  */
101  void input();
102 
103  /** Set the input pin mode for all the pins in bus
104  *
105  * @param pull PullUp, PullDown, PullNone
106  */
107  void mode(PinMode pull);
108 
109  /** Binary mask of bus pins connected to actual pins (not NC pins)
110  * If bus pin is in NC state make corresponding bit will be cleared (set to 0), else bit will be set to 1
111  *
112  * @returns
113  * Binary mask of connected pins
114  */
115  int mask()
116  {
117  // No lock needed since _nc_mask is not modified outside the constructor
118  return _nc_mask;
119  }
120 
121  /** A shorthand for write()
122  * \sa BusInOut::write()
123  */
124  BusInOut &operator= (int v);
125  BusInOut &operator= (BusInOut &rhs);
126 
127  /** Access to particular bit in random-iterator fashion
128  * @param index Bit Position
129  */
130  DigitalInOut &operator[](int index);
131 
132  /** A shorthand for read()
133  * \sa BusInOut::read()
134  */
135  operator int();
136 
137 protected:
138 #if !defined(DOXYGEN_ONLY)
139  virtual void lock();
140  virtual void unlock();
141  DigitalInOut *_pin[16];
142 
143  /* Mask of bus's NC pins
144  * If bit[n] is set to 1 - pin is connected
145  * if bit[n] is cleared - pin is not connected (NC)
146  */
147  int _nc_mask;
148 
149  PlatformMutex _mutex;
150 #endif //!defined(DOXYGEN_ONLY)
151 };
152 
153 /** @}*/
154 
155 } // namespace mbed
156 
157 #endif
mbed::BusInOut::operator[]
DigitalInOut & operator[](int index)
Access to particular bit in random-iterator fashion.
mbed::BusInOut
A digital input output bus, used for setting the state of a collection of pins.
Definition: BusInOut.h:38
mbed::BusInOut::mask
int mask()
Binary mask of bus pins connected to actual pins (not NC pins) If bus pin is in NC state make corresp...
Definition: BusInOut.h:115
mbed::BusInOut::input
void input()
Set all the pins in bus as an input.
mbed::DigitalInOut
A digital input/output, used for setting or reading a bi-directional pin.
Definition: DigitalInOut.h:35
mbed::NonCopyable
Prevents generation of copy constructor and copy assignment operator in derived classes.
Definition: NonCopyable.h:169
PlatformMutex
The PlatformMutex class is used to synchronize the execution of threads.
Definition: PlatformMutex.h:47
mbed::BusInOut::output
void output()
Set all the pins in bus as output.
mbed::BusInOut::BusInOut
BusInOut(PinName p0, PinName p1=NC, PinName p2=NC, PinName p3=NC, PinName p4=NC, PinName p5=NC, PinName p6=NC, PinName p7=NC, PinName p8=NC, PinName p9=NC, PinName p10=NC, PinName p11=NC, PinName p12=NC, PinName p13=NC, PinName p14=NC, PinName p15=NC)
Create a BusInOut, connected to the specified pins.
mbed::BusInOut::mode
void mode(PinMode pull)
Set the input pin mode for all the pins in bus.
mbed::BusInOut::write
void write(int value)
Write the value to the output bus.
mbed::BusInOut::read
int read()
Read the value currently output on the bus.
mbed::BusInOut::operator=
BusInOut & operator=(int v)
A shorthand for write()
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