tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_STM/TARGET_STM32F4XX/port_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 "port_api.h"
  17 #include "pinmap.h"
  18 #include "gpio_api.h"
  19
  20 #if DEVICE_PORTIN || DEVICE_PORTOUT
  21
  22 PinName port_pin(PortName port, int pin_n) {
  23     return pin_n + (port << 4);
  24 }
  25
  26 void port_init(port_t *obj, PortName port, int mask, PinDirection dir) {
  27     obj->port = port;
  28     obj->mask = mask;
  29
  30     uint32_t port_index = (uint32_t) port;
  31
  32     GPIO_TypeDef *port_reg = (GPIO_TypeDef *)(GPIOA_BASE + (port_index << 10));
  33     // Enable GPIO peripheral clock
  34     RCC->AHB1ENR |= 1 << port_index;
  35
  36     obj->reg_mode = &port_reg->MODER;
  37     obj->reg_set = &port_reg->BSRRH;
  38     obj->reg_clr = &port_reg->BSRRL;
  39     obj->reg_in  = &port_reg->IDR;
  40     obj->reg_out  = &port_reg->ODR;
  41
  42     port_dir(obj, dir);
  43 }
  44
  45 void port_mode(port_t *obj, PinMode mode) {
  46     uint32_t i;
  47     // The mode is set per pin: reuse pinmap logic
  48     for (i=0; i<16; i++) {
  49         if (obj->mask & (1<<i)) {
  50             pin_mode(port_pin(obj->port, i), mode);
  51         }
  52     }
  53 }
  54
  55 void port_dir(port_t *obj, PinDirection dir) {
  56     obj->direction = dir;
  57     uint32_t tmp = *obj->reg_mode;
  58     for (int i=0; i<16; i++) {
  59         if (obj->mask & (1 << i)) {
  60             // Clear the mode bits (i.e. set to input)
  61             tmp &= ~(0x3 << (i << 1));
  62             if (dir == PIN_OUTPUT) {
  63                 // Set to output
  64                 tmp |= 0x1 << (i << 1);
  65             }
  66         }
  67     }
  68     *obj->reg_mode = tmp;
  69 }
  70
  71 void port_write(port_t *obj, int value) {
  72     *obj->reg_out = (*obj->reg_out & ~obj->mask) | (value & obj->mask);
  73 }
  74
  75 int port_read(port_t *obj) {
  76     switch (obj->direction) {
  77         case PIN_OUTPUT: return *obj->reg_out & obj->mask;
  78         case PIN_INPUT: return *obj->reg_in & obj->mask;
  79     }
  80     return 0;
  81 }
  82
  83 #endif