tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC82X/gpio_api.c

   1 /* mbed Microcontroller Library
   2  * Copyright (c) 2006-2013 ARM Limited
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 #include "mbed_assert.h"
  17 #include "gpio_api.h"
  18 #include "pinmap.h"
  19
  20 static int  gpio_enabled = 0;
  21
  22 static void gpio_enable(void)
  23 {
  24     gpio_enabled = 1;
  25
  26     /* Enable AHB clock to the GPIO domain. */
  27     LPC_SYSCON->SYSAHBCLKCTRL |= (1 << 6);
  28
  29     /* Peripheral reset control to GPIO and GPIO INT, a "1" bring it out of reset. */
  30     LPC_SYSCON->PRESETCTRL &= ~(1 << 10);
  31     LPC_SYSCON->PRESETCTRL |=  (1 << 10);
  32 }
  33
  34 uint32_t gpio_set(PinName pin)
  35 {
  36     if (!gpio_enabled)
  37          gpio_enable();
  38
  39     return (1 << ((int)pin >> PIN_SHIFT));
  40 }
  41
  42 void gpio_init(gpio_t *obj, PinName pin)
  43 {
  44     obj->pin = pin;
  45     if (pin == (PinName)NC)
  46         return;
  47
  48     obj->mask = gpio_set(pin);
  49
  50     obj->reg_set = &LPC_GPIO_PORT->SET0;
  51     obj->reg_clr = &LPC_GPIO_PORT->CLR0;
  52     obj->reg_in  = &LPC_GPIO_PORT->PIN0;
  53     obj->reg_dir = &LPC_GPIO_PORT->DIR0;
  54 }
  55
  56 void gpio_mode(gpio_t *obj, PinMode mode)
  57 {
  58     pin_mode(obj->pin, mode);
  59 }
  60
  61 void gpio_dir(gpio_t *obj, PinDirection direction)
  62 {
  63     MBED_ASSERT(obj->pin != (PinName)NC);
  64     switch (direction) {
  65         case PIN_INPUT :
  66             *obj->reg_dir &= ~obj->mask;
  67             break;
  68         case PIN_OUTPUT:
  69             *obj->reg_dir |= obj->mask;
  70             break;
  71     }
  72 }