wiringPi_Blueberry/devLib/piFaceOld.c

178 lines
4.3 KiB
C
Raw Normal View History

2023-08-11 15:53:17 +08:00
/*
* piFace.:
* Copyright (c) 2012-2016 Gordon Henderson
*
* This file to interface with the PiFace peripheral device which
* has an MCP23S17 GPIO device connected via the SPI bus.
***********************************************************************
* 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 <stdint.h>
#include <wiringPi.h>
#include <wiringPiSPI.h>
#include "../wiringPi/mcp23x0817.h"
#include "piFace.h"
#define PIFACE_SPEED 4000000
#define PIFACE_DEVNO 0
/*
* writeByte:
* Write a byte to a register on the MCP23S17 on the SPI bus.
*********************************************************************************
*/
static void writeByte (uint8_t reg, uint8_t data)
{
uint8_t spiData [4] ;
spiData [0] = CMD_WRITE ;
spiData [1] = reg ;
spiData [2] = data ;
wiringPiSPIDataRW (PIFACE_DEVNO, spiData, 3) ;
}
/*
* readByte:
* Read a byte from a register on the MCP23S17 on the SPI bus.
*********************************************************************************
*/
static uint8_t readByte (uint8_t reg)
{
uint8_t spiData [4] ;
spiData [0] = CMD_READ ;
spiData [1] = reg ;
wiringPiSPIDataRW (PIFACE_DEVNO, spiData, 3) ;
return spiData [2] ;
}
/*
* myDigitalWrite:
* Perform the digitalWrite function on the PiFace board
*********************************************************************************
*/
void myDigitalWrite (struct wiringPiNodeStruct *node, int pin, int value)
{
uint8_t mask, old ;
pin -= node->pinBase ;
mask = 1 << pin ;
old = readByte (MCP23x17_GPIOA) ;
if (value == 0)
old &= (~mask) ;
else
old |= mask ;
writeByte (MCP23x17_GPIOA, old) ;
}
/*
* myDigitalRead:
* Perform the digitalRead function on the PiFace board
*********************************************************************************
*/
int myDigitalRead (struct wiringPiNodeStruct *node, int pin)
{
uint8_t mask, reg ;
mask = 1 << ((pin - node->pinBase) & 7) ;
if (pin < 8)
reg = MCP23x17_GPIOB ; // Input regsiter
else
reg = MCP23x17_OLATA ; // Output latch regsiter
if ((readByte (reg) & mask) != 0)
return HIGH ;
else
return LOW ;
}
/*
* myPullUpDnControl:
* Perform the pullUpDnControl function on the PiFace board
*********************************************************************************
*/
void myPullUpDnControl (struct wiringPiNodeStruct *node, int pin, int pud)
{
uint8_t mask, old ;
mask = 1 << (pin - node->pinBase) ;
old = readByte (MCP23x17_GPPUB) ;
if (pud == 0)
old &= (~mask) ;
else
old |= mask ;
writeByte (MCP23x17_GPPUB, old) ;
}
/*
* piFaceSetup
* Setup the SPI interface and initialise the MCP23S17 chip
* We create one node with 16 pins - each if the first 8 pins being read
* and write - although the operations actually go to different
* hardware ports. The top 8 let you read the state of the output register.
*********************************************************************************
*/
int piFaceSetup (const int pinBase)
{
int x ;
struct wiringPiNodeStruct *node ;
if ((x = wiringPiSPISetup (PIFACE_DEVNO, PIFACE_SPEED)) < 0)
return x ;
// Setup the MCP23S17
writeByte (MCP23x17_IOCON, IOCON_INIT) ;
writeByte (MCP23x17_IODIRA, 0x00) ; // Port A -> Outputs
writeByte (MCP23x17_IODIRB, 0xFF) ; // Port B -> Inputs
node = wiringPiNewNode (pinBase, 16) ;
node->digitalRead = myDigitalRead ;
node->digitalWrite = myDigitalWrite ;
node->pullUpDnControl = myPullUpDnControl ;
return 0 ;
}