gpio_api.c

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #include "gpio_api.h"
00017 #include "pinmap.h"
00018 
00019 uint32_t gpio_set(PinName pin) {
00020     int f = ((pin == P0_11) ||
00021              (pin == P0_12) ||
00022              (pin == P0_13) ||
00023              (pin == P0_14)) ? (1) : (0);
00024     
00025     pin_function(pin, f);
00026     
00027     return (1 << ((int)pin & 0x1F));
00028 }
00029 
00030 void gpio_init(gpio_t *obj, PinName pin, PinDirection direction) {
00031     if(pin == NC) return;
00032 
00033     obj->pin = pin;
00034     obj->mask = gpio_set(pin);
00035     
00036     unsigned int port = (unsigned int)pin >> PORT_SHIFT;
00037     
00038     obj->reg_set = &LPC_GPIO->SET[port];
00039     obj->reg_clr = &LPC_GPIO->CLR[port];
00040     obj->reg_in  = &LPC_GPIO->PIN[port];
00041     obj->reg_dir = &LPC_GPIO->DIR[port];
00042     
00043     gpio_dir(obj, direction);
00044     switch (direction) {
00045         case PIN_OUTPUT: pin_mode(pin, PullNone); break;
00046         case PIN_INPUT : pin_mode(pin, PullDown); break;
00047     }
00048 }
00049 
00050 void gpio_mode(gpio_t *obj, PinMode mode) {
00051     pin_mode(obj->pin, mode);
00052 }
00053 
00054 void gpio_dir(gpio_t *obj, PinDirection direction) {
00055     switch (direction) {
00056         case PIN_INPUT : *obj->reg_dir &= ~obj->mask; break;
00057         case PIN_OUTPUT: *obj->reg_dir |=  obj->mask; break;
00058     }
00059 }