You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
149 lines
3.6 KiB
149 lines
3.6 KiB
/* |
|
* mcp23008.c: |
|
* Extend wiringPi with the MCP 23008 I2C GPIO expander chip |
|
* Copyright (c) 2013 Gordon Henderson |
|
*********************************************************************** |
|
* This file is part of wiringPi: |
|
* https://projects.drogon.net/raspberry-pi/wiringpi/ |
|
* |
|
* wiringPi is free software: you can redistribute it and/or modify |
|
* it under the terms of the GNU Lesser General Public License as |
|
* published by the Free Software Foundation, either version 3 of the |
|
* License, or (at your option) any later version. |
|
* |
|
* wiringPi is distributed in the hope that it will be useful, |
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
|
* GNU Lesser General Public License for more details. |
|
* |
|
* You should have received a copy of the GNU Lesser General Public |
|
* License along with wiringPi. |
|
* If not, see <http://www.gnu.org/licenses/>. |
|
*********************************************************************** |
|
*/ |
|
|
|
#include <stdio.h> |
|
#include <pthread.h> |
|
|
|
#include "wiringPi.h" |
|
#include "wiringPiI2C.h" |
|
#include "mcp23x0817.h" |
|
|
|
#include "mcp23008.h" |
|
|
|
|
|
/* |
|
* myPinMode: |
|
********************************************************************************* |
|
*/ |
|
|
|
static void myPinMode (struct wiringPiNodeStruct *node, int pin, int mode) |
|
{ |
|
int mask, old, reg ; |
|
|
|
reg = MCP23x08_IODIR ; |
|
mask = 1 << (pin - node->pinBase) ; |
|
old = wiringPiI2CReadReg8 (node->fd, reg) ; |
|
|
|
if (mode == OUTPUT) |
|
old &= (~mask) ; |
|
else |
|
old |= mask ; |
|
|
|
wiringPiI2CWriteReg8 (node->fd, reg, old) ; |
|
} |
|
|
|
|
|
/* |
|
* myPullUpDnControl: |
|
********************************************************************************* |
|
*/ |
|
|
|
static void myPullUpDnControl (struct wiringPiNodeStruct *node, int pin, int mode) |
|
{ |
|
int mask, old, reg ; |
|
|
|
reg = MCP23x08_GPPU ; |
|
mask = 1 << (pin - node->pinBase) ; |
|
|
|
old = wiringPiI2CReadReg8 (node->fd, reg) ; |
|
|
|
if (mode == PUD_UP) |
|
old |= mask ; |
|
else |
|
old &= (~mask) ; |
|
|
|
wiringPiI2CWriteReg8 (node->fd, reg, old) ; |
|
} |
|
|
|
|
|
/* |
|
* myDigitalWrite: |
|
********************************************************************************* |
|
*/ |
|
|
|
static void myDigitalWrite (struct wiringPiNodeStruct *node, int pin, int value) |
|
{ |
|
int bit, old ; |
|
|
|
bit = 1 << ((pin - node->pinBase) & 7) ; |
|
|
|
old = node->data2 ; |
|
if (value == LOW) |
|
old &= (~bit) ; |
|
else |
|
old |= bit ; |
|
|
|
wiringPiI2CWriteReg8 (node->fd, MCP23x08_GPIO, old) ; |
|
node->data2 = old ; |
|
} |
|
|
|
|
|
/* |
|
* myDigitalRead: |
|
********************************************************************************* |
|
*/ |
|
|
|
static int myDigitalRead (struct wiringPiNodeStruct *node, int pin) |
|
{ |
|
int mask, value ; |
|
|
|
mask = 1 << ((pin - node->pinBase) & 7) ; |
|
value = wiringPiI2CReadReg8 (node->fd, MCP23x08_GPIO) ; |
|
|
|
if ((value & mask) == 0) |
|
return LOW ; |
|
else |
|
return HIGH ; |
|
} |
|
|
|
|
|
/* |
|
* mcp23008Setup: |
|
* Create a new instance of an MCP23008 I2C GPIO interface. We know it |
|
* has 8 pins, so all we need to know here is the I2C address and the |
|
* user-defined pin base. |
|
********************************************************************************* |
|
*/ |
|
|
|
int mcp23008Setup (const int pinBase, const int i2cAddress) |
|
{ |
|
int fd ; |
|
struct wiringPiNodeStruct *node ; |
|
|
|
if ((fd = wiringPiI2CSetup (i2cAddress)) < 0) |
|
return FALSE ; |
|
|
|
wiringPiI2CWriteReg8 (fd, MCP23x08_IOCON, IOCON_INIT) ; |
|
|
|
node = wiringPiNewNode (pinBase, 8) ; |
|
|
|
node->fd = fd ; |
|
node->pinMode = myPinMode ; |
|
node->pullUpDnControl = myPullUpDnControl ; |
|
node->digitalRead = myDigitalRead ; |
|
node->digitalWrite = myDigitalWrite ; |
|
node->data2 = wiringPiI2CReadReg8 (fd, MCP23x08_OLAT) ; |
|
|
|
return TRUE ; |
|
}
|
|
|