summaryrefslogtreecommitdiffstats
path: root/mbed/drivers/DigitalInOut.h
blob: 65149051411e19173f0b7769ac8c2200942255c0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
/* mbed Microcontroller Library
 * Copyright (c) 2006-2013 ARM Limited
 *
 * 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
 */
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 mode 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()
     */
    DigitalInOut& operator= (int value) {
        // Underlying write is thread safe
        write(value);
        return *this;
    }

    DigitalInOut& operator= (DigitalInOut& rhs) {
        core_util_critical_section_enter();
        write(rhs.read());
        core_util_critical_section_exit();
        return *this;
    }

    /** A shorthand for read()
     */
    operator int() {
        // Underlying call is thread safe
        return read();
    }

protected:
    gpio_t gpio;
};

} // namespace mbed

#endif

/** @}*/