AbstractGpioExpender.h

00001 /* mbed simplified interface for GPIO expender (e.g. Microchip MCP23x17)
00002  * Copyright (c) 2014-2015 ygarcia, MIT License
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy of this software 
00005  * and associated documentation files (the "Software"), to deal in the Software without restriction, 
00006  * including without limitation the rights to use, copy, modify, merge, publish, distribute, 
00007  * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is 
00008  * furnished to do so, subject to the following conditions:
00009  *
00010  * The above copyright notice and this permission notice shall be included in all copies or 
00011  * substantial portions of the Software.
00012  *
00013  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING 
00014  * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
00015  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
00016  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
00017  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00018  */
00019 #pragma once
00020 
00021 #include <list>
00022 
00023 #include <mbed.h>
00024 
00025 #define GPA0        0
00026 #define GPA1        1
00027 #define GPA2        2
00028 #define GPA3        3
00029 #define GPA4        4
00030 #define GPA5        5
00031 #define GPA6        6
00032 #define GPA7        7
00033 #define GPB0        8
00034 #define GPB1        9
00035 #define GPB2        10
00036 #define GPB3        11
00037 #define GPB4        12
00038 #define GPB5        13
00039 #define GPB6        14
00040 #define GPB7        15
00041 #define GPIO_MAX    GPB7
00042 #define GPIO_MED    GPB0
00043 #define GPIO_SIZE   8
00044 
00045 /** This class describes a simplified interface for GPIO expender (e.g. Microchip MCP23x17)
00046  */
00047 class AbstractGpioExpender {
00048 public:
00049     /** Interrupt modes
00050      */
00051     enum InterruptModes {
00052         OnChange = 0x00,
00053         OnRising = 0x01,
00054         OnFalling = 0x03
00055     };
00056     
00057     /** Pull modes
00058      */
00059     enum PullModes {
00060         PullOff = 0x00,
00061         PullUp = 0x01,
00062         PullDown = 0x03
00063     };
00064     
00065     /** Reset the device
00066      */
00067     virtual void reset() = 0;
00068 
00069     /** Setup device interrupt mechanism
00070      * @param p_mirroring Set to 0x00 to disable INTA/B mirroring, 0x01 otherwise. Default: 0x00
00071      * @param p_openDrain Set to 0x00 for active driver output, 0x01 for opn drain output. Default: 0x00
00072      * @param p_polarity Set to 0x00 for interrupt active low, 0x01 otherwise. Default: 0x00
00073      */
00074     virtual void setupInterrupts(const unsigned char p_mirroring = 0x00, const unsigned char p_openDrain = 0x00, const unsigned char p_polarity = 0x00) = 0;
00075     
00076     /** Setup interrupt mode for a specific IO port
00077      * @param p_gpioId The IO port identifier
00078      * @param p_mode  The interrupt mode
00079      * @return 0 on success, -1 on wrong parameters and -2 otherwise
00080      */
00081     virtual int setupInterruptPin(const unsigned char p_gpioId, const InterruptModes p_mode = OnRising) = 0;
00082     
00083     /** Setup pull mode for a specific IO port
00084      * @param p_gpioId The IO port identifier
00085      * @param p_mode  The interrupt mode
00086      * @return 0 on success, -1 on wrong parameters and -2 otherwise
00087      */
00088     virtual int setupPullPin(const unsigned char p_gpioId, const PullModes p_mode = PullOff) = 0;
00089     
00090     /** Get interrupt information and clear it
00091      * @param p_gpioId The IO port identifier where the interrupt occured
00092      * @param p_value  The logic value on the pin port where the interrupt occured
00093      * @return 0 on success, -1 on wrong parameters and -2 otherwise
00094      */
00095     virtual int getLastInterruptPinAndValue(unsigned char * p_gpioId, unsigned char * p_value) = 0;
00096     
00097     /** Attach a function to call when a interrupt occurs on the GPIOA input ports
00098      * @param p_fptr The pointer to the "C" callback function
00099      */
00100     virtual void setIntrACallback(void (* p_fptr)(void)) = 0;
00101     
00102     /** Attach a function to call when a interrupt occurs on the GPIOB input ports
00103      * @param p_fptr The pointer to the "C" callback function
00104      */
00105     virtual void setIntrBCallback(void (* p_fptr)(void)) = 0;
00106     
00107     /** Read the specific GPIO port pin
00108      * @param p_gpioId The GPIO port pin to be read 
00109      * @param p_value The GPIO port pin value
00110      * @return 0 on success, -1 on wrong parameters and -2 otherwise
00111      */
00112     virtual int read(const unsigned char p_gpioId, unsigned char * p_value) = 0;
00113     
00114     /** Write value to the specific GPIO port pin
00115      * @param p_gpioId The GPIO port pin to be written
00116      * @param p_value The GPIO port pin value
00117      * @return 0 on success, -1 on wrong parameters and -2 otherwise
00118      */
00119     virtual int write(const unsigned char p_gpioId, const unsigned char p_value) = 0;
00120     
00121     virtual unsigned char createBus(const std::list<unsigned char> p_lines, const PinMode p_mode = PullNone) = 0;
00122     virtual void deleteBus(const unsigned char p_busId) = 0;
00123     virtual int busRead(const unsigned char p_busId, unsigned short * p_value) = 0;
00124     virtual int busWrite(const unsigned char p_busId, const unsigned short p_value) = 0;
00125     
00126 protected:
00127     virtual bool writeRegister(const unsigned char p_registerId, const unsigned char p_value) = 0;
00128     virtual bool readRegister(const unsigned char p_registerId, unsigned char * p_value) = 0;
00129 
00130 }; // End of class AbstractGpioExpender