1 /*
2 * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 *
6 * GPIO -- General Purpose Input/Output
7 *
8 * Defines a simple and generic interface to access GPIO device.
9 *
10 */
11
12 #include <assert.h>
13 #include <errno.h>
14 #include <gpio.h>
15
16 /*
17 * The gpio implementation
18 */
19 static const gpio_ops_t *ops;
20
gpio_get_direction(int gpio)21 int gpio_get_direction(int gpio)
22 {
23 assert(ops);
24 assert(ops->get_direction != 0);
25 assert(gpio >= 0);
26
27 return ops->get_direction(gpio);
28 }
29
gpio_set_direction(int gpio,int direction)30 void gpio_set_direction(int gpio, int direction)
31 {
32 assert(ops);
33 assert(ops->set_direction != 0);
34 assert((direction == GPIO_DIR_OUT) || (direction == GPIO_DIR_IN));
35 assert(gpio >= 0);
36
37 ops->set_direction(gpio, direction);
38 }
39
gpio_get_value(int gpio)40 int gpio_get_value(int gpio)
41 {
42 assert(ops);
43 assert(ops->get_value != 0);
44 assert(gpio >= 0);
45
46 return ops->get_value(gpio);
47 }
48
gpio_set_value(int gpio,int value)49 void gpio_set_value(int gpio, int value)
50 {
51 assert(ops);
52 assert(ops->set_value != 0);
53 assert((value == GPIO_LEVEL_LOW) || (value == GPIO_LEVEL_HIGH));
54 assert(gpio >= 0);
55
56 ops->set_value(gpio, value);
57 }
58
gpio_set_pull(int gpio,int pull)59 void gpio_set_pull(int gpio, int pull)
60 {
61 assert(ops);
62 assert(ops->set_pull != 0);
63 assert((pull == GPIO_PULL_NONE) || (pull == GPIO_PULL_UP) ||
64 (pull == GPIO_PULL_DOWN));
65 assert(gpio >= 0);
66
67 ops->set_pull(gpio, pull);
68 }
69
gpio_get_pull(int gpio)70 int gpio_get_pull(int gpio)
71 {
72 assert(ops);
73 assert(ops->get_pull != 0);
74 assert(gpio >= 0);
75
76 return ops->get_pull(gpio);
77 }
78
79 /*
80 * Initialize the gpio. The fields in the provided gpio
81 * ops pointer must be valid.
82 */
gpio_init(const gpio_ops_t * ops_ptr)83 void gpio_init(const gpio_ops_t *ops_ptr)
84 {
85 assert(ops_ptr != 0 &&
86 (ops_ptr->get_direction != 0) &&
87 (ops_ptr->set_direction != 0) &&
88 (ops_ptr->get_value != 0) &&
89 (ops_ptr->set_value != 0));
90
91 ops = ops_ptr;
92 }
93