src/main/drivers/io_port_expander.c

   1 /*
   2  * This file is part of INAV.
   3  *
   4  * This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   6  * You can obtain one at http://mozilla.org/MPL/2.0/.
   7  *
   8  * Alternatively, the contents of this file may be used under the terms
   9  * of the GNU General Public License Version 3, as described below:
  10  *
  11  * This file is free software: you may copy, redistribute and/or modify
  12  * it under the terms of the GNU General Public License as published by the
  13  * Free Software Foundation, either version 3 of the License, or (at your
  14  * option) any later version.
  15  *
  16  * This file is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
  19  * Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program. If not, see http://www.gnu.org/licenses/.
  23  */
  24
  25 #include <stdbool.h>
  26 #include "platform.h"
  27 #include "drivers/io_port_expander.h"
  28 #include "drivers/io_pcf8574.h"
  29
  30 #ifdef USE_I2C_IO_EXPANDER
  31
  32 static ioPortExpanderState_t ioPortExpanderState;
  33
  34 void ioPortExpanderInit(void)
  35 {
  36
  37     ioPortExpanderState.active = pcf8574Init();
  38
  39     if (ioPortExpanderState.active) {
  40         ioPortExpanderState.state = 0x00;
  41         pcf8574Write(ioPortExpanderState.state); //Set all ports to OFF
  42     }
  43
  44 }
  45
  46 void ioPortExpanderSet(uint8_t pin, uint8_t value)
  47 {
  48     if (pin > 7) {
  49         return;
  50     }
  51
  52     //Cast to 0/1
  53     value = (bool) value;
  54
  55     ioPortExpanderState.state ^= (-value ^ ioPortExpanderState.state) & (1UL << pin);
  56     ioPortExpanderState.shouldSync = true;
  57 }
  58
  59 void ioPortExpanderSync(void)
  60 {
  61     if (ioPortExpanderState.active && ioPortExpanderState.shouldSync) {
  62         pcf8574Write(ioPortExpanderState.state);
  63         ioPortExpanderState.shouldSync = false;
  64     }
  65 }
  66
  67 #endif