Diff: AbstractGpioExpender.h

Revision:

2:3bea48e1505c

Parent:

1:ec9e770173d5

--- a/AbstractGpioExpender.h	Fri Jan 09 15:35:40 2015 +0000
+++ b/AbstractGpioExpender.h	Tue Jan 13 10:09:01 2015 +0000
@@ -1,3 +1,21 @@
+/* mbed simplified interface for GPIO expender (e.g. Microchip MCP23x17)
+ * Copyright (c) 2014-2015 ygarcia, MIT License
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software 
+ * and associated documentation files (the "Software"), to deal in the Software without restriction, 
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute, 
+ * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is 
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or 
+ * substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING 
+ * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
 #pragma once
 
 #include <list>
@@ -24,6 +42,8 @@
 #define GPIO_MED    GPB0
 #define GPIO_SIZE   8
 
+/** This class describes a simplified interface for GPIO expender (e.g. Microchip MCP23x17)
+ */
 class AbstractGpioExpender {
 public:
     /** Interrupt modes
@@ -34,40 +54,68 @@
         OnFalling = 0x03
     };
     
+    /** Pull modes
+     */
+    enum PullModes {
+        PullOff = 0x00,
+        PullUp = 0x01,
+        PullDown = 0x03
+    };
+    
     /** Reset the device
      */
     virtual void reset() = 0;
 
-    /** Setup interrupt mechanism for all GPIO ports
+    /** Setup device interrupt mechanism
      * @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
+    /** Setup interrupt mode 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
+     * @return 0 on success, -1 on wrong parameters and -2 otherwise
      */
     virtual int setupInterruptPin(const unsigned char p_gpioId, const InterruptModes p_mode = OnRising) = 0;
     
+    /** Setup pull mode for a specific IO port
+     * @param p_gpioId The IO port identifier
+     * @param p_mode  The interrupt mode
+     * @return 0 on success, -1 on wrong parameters and -2 otherwise
+     */
+    virtual int setupPullPin(const unsigned char p_gpioId, const PullModes p_mode = PullOff) = 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
+     * @return 0 on success, -1 on wrong parameters and -2 otherwise
      */
-    virtual int getLastInterruptPin(unsigned char * p_gpioId, unsigned char * p_value) = 0;
+    virtual int getLastInterruptPinAndValue(unsigned char * p_gpioId, unsigned char * p_value) = 0;
     
     /** Attach a function to call when a interrupt occurs on the GPIOA input ports
+     * @param p_fptr The pointer to the "C" callback function
      */
     virtual void setIntrACallback(void (* p_fptr)(void)) = 0;
     
-    /** Attach a function to call when a rising edge occurs on the input
+    /** Attach a function to call when a interrupt occurs on the GPIOB input ports
+     * @param p_fptr The pointer to the "C" callback function
      */
     virtual void setIntrBCallback(void (* p_fptr)(void)) = 0;
     
+    /** Read the specific GPIO port pin
+     * @param p_gpioId The GPIO port pin to be read 
+     * @param p_value The GPIO port pin value
+     * @return 0 on success, -1 on wrong parameters and -2 otherwise
+     */
     virtual int read(const unsigned char p_gpioId, unsigned char * p_value) = 0;
+    
+    /** Write value to the specific GPIO port pin
+     * @param p_gpioId The GPIO port pin to be written
+     * @param p_value The GPIO port pin value
+     * @return 0 on success, -1 on wrong parameters and -2 otherwise
+     */
     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;