drivers/gpio/gpio.c

   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
  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
  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
  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
  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
  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
  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  */
  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 }