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     LPC_SC->SCS |= 1; // High speed GPIO is enabled on ports 0 and 1
00021     
00022     pin_function(pin, 0);
00023     
00024     return (1 << ((int)pin & 0x1F));
00025 }
00026 
00027 void gpio_init(gpio_t *obj, PinName pin, PinDirection direction) {
00028     if (pin == NC) return;
00029     
00030     obj->pin = pin;
00031     obj->mask = gpio_set(pin);
00032     
00033     LPC_GPIO_TypeDef *port_reg = (LPC_GPIO_TypeDef *) ((int)pin & ~0x1F);
00034     
00035     obj->reg_set = &port_reg->FIOSET;
00036     obj->reg_clr = &port_reg->FIOCLR;
00037     obj->reg_in  = &port_reg->FIOPIN;
00038     obj->reg_dir = &port_reg->FIODIR;
00039     
00040     gpio_dir(obj, direction);
00041     switch (direction) {
00042         case PIN_OUTPUT: pin_mode(pin, PullNone); break;
00043         case PIN_INPUT : pin_mode(pin, PullDown); break;
00044     }
00045 }
00046 
00047 void gpio_mode(gpio_t *obj, PinMode mode) {
00048     pin_mode(obj->pin, mode);
00049 }
00050 
00051 void gpio_dir(gpio_t *obj, PinDirection direction) {
00052     switch (direction) {
00053         case PIN_INPUT : *obj->reg_dir &= ~obj->mask; break;
00054         case PIN_OUTPUT: *obj->reg_dir |=  obj->mask; break;
00055     }
00056 }