This library provides simplified I2C access to a Microchip MCP23x17 GPIO expender device, including a general interface for any GPIO expender

Dependents:   MCP23017App

AbstractGpioExpender.h

Committer:
Yann
Date:
2015-01-09
Revision:
0:ebd3a7cc9b92
Child:
1:ec9e770173d5

File content as of revision 0:ebd3a7cc9b92:

#pragma once

#include <list>

#include <mbed.h>

#define GPA0        0
#define GPA1        1
#define GPA2        2
#define GPA3        3
#define GPA4        4
#define GPA5        5
#define GPA6        6
#define GPA7        7
#define GPB0        8
#define GPB1        9
#define GPB2        10
#define GPB3        11
#define GPB4        12
#define GPB5        13
#define GPB6        14
#define GPB7        15
#define GPIO_MAX    GPB7
#define GPIO_MED    GPB0
#define GPIO_SIZE   8

class AbstractGpioExpender {
public:
    /** Interrupt modes
     */
    enum InterruptModes {
        OnChange = 0x00,
        OnRising = 0x01,
        OnFalling = 0x03
    };
    
    /** Reset the device
     */
    virtual void reset() = 0;

    /** Setup interrupt mechanism for all GPIO ports
     * @param p_mirroring Set to 0x00 to disable INTA/B mirroring, 0x01 otherwise. Default: 0x00
     * @param p_openDrain Set to 0x00 for active driver output, 0x01 for opn drain output. Default: 0x00
     * @param p_polarity Set to 0x00 for interrupt active low, 0x01 otherwise. Default: 0x00
     */
    virtual void setupInterrupts(const unsigned char p_mirroring = 0x00, const unsigned char p_openDrain = 0x00, const unsigned char p_polarity = 0x00) = 0;
    
    /** Setup interrupt for a specific IO port
     * @param p_gpioId The IO port identifier
     * @param p_mode  The interrupt mode
     * @return 0 on success, negative value otherwise
     */
    virtual int setupInterruptPin(const unsigned char p_gpioId, const InterruptModes p_mode = OnRising) = 0;
    
    /** Get interrupt information and clear it
     * @param p_gpioId The IO port identifier where the interrupt occured
     * @param p_value  The logic value on the pin port where the interrupt occured
     * @return 0 on success, negative value otherwise
     */
    virtual int getLastInterruptPin(unsigned char * p_gpioId, unsigned char * p_value) = 0;
    
    /** Attach a function to call when a interrupt occurs on the GPIOA input ports
     */
    virtual void setIntrACallback(void (* p_fptr)(void)) = 0;
    
    /** Attach a function to call when a rising edge occurs on the input
     */
    virtual void setIntrBCallback(void (* p_fptr)(void)) = 0;
    
    virtual int read(const unsigned char p_gpioId, unsigned char * p_value) = 0;
    virtual int write(const unsigned char p_gpioId, const unsigned char p_value) = 0;
    
    virtual unsigned char createBus(const std::list<unsigned char> p_lines, const PinMode p_mode = PullNone) = 0;
    virtual void deleteBus(const unsigned char p_busId) = 0;
    virtual int busRead(const unsigned char p_busId) = 0;
    virtual int busWrite(const unsigned char p_busId, const unsigned char p_value) = 0;
    
protected:
    virtual bool writeRegister(const unsigned char p_registerId, const unsigned char p_value) = 0;
    virtual bool readRegister(const unsigned char p_registerId, unsigned char * p_value) = 0;

}; // End of class AbstractGpioExpender