CAN.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #ifndef MBED_CAN_H
00017 #define MBED_CAN_H
00018 
00019 #include "platform.h"
00020 
00021 #if DEVICE_CAN
00022 
00023 #include "can_api.h"
00024 #include "can_helper.h"
00025 #include "Callback.h"
00026 #include "PlatformMutex.h"
00027 
00028 namespace mbed {
00029 
00030 /** CANMessage class
00031  *
00032  * @Note Synchronization level: Thread safe
00033  */
00034 class CANMessage : public CAN_Message {
00035 
00036 public:
00037     /** Creates empty CAN message.
00038      */
00039     CANMessage() : CAN_Message() {
00040         len    = 8;
00041         type   = CANData;
00042         format = CANStandard;
00043         id     = 0;
00044         memset(data, 0, 8);
00045     }
00046 
00047     /** Creates CAN message with specific content.
00048      */
00049     CANMessage(int _id, const char *_data, char _len = 8, CANType _type = CANData, CANFormat _format = CANStandard) {
00050       len    = _len & 0xF;
00051       type   = _type;
00052       format = _format;
00053       id     = _id;
00054       memcpy(data, _data, _len);
00055     }
00056 
00057     /** Creates CAN remote message.
00058      */
00059     CANMessage(int _id, CANFormat _format = CANStandard) {
00060       len    = 0;
00061       type   = CANRemote;
00062       format = _format;
00063       id     = _id;
00064       memset(data, 0, 8);
00065     }
00066 };
00067 
00068 /** A can bus client, used for communicating with can devices
00069  */
00070 class CAN {
00071 
00072 public:
00073     /** Creates an CAN interface connected to specific pins.
00074      *
00075      *  @param rd read from transmitter
00076      *  @param td transmit to transmitter
00077      *
00078      * Example:
00079      * @code
00080      * #include "mbed.h"
00081      *
00082      * Ticker ticker;
00083      * DigitalOut led1(LED1);
00084      * DigitalOut led2(LED2);
00085      * CAN can1(p9, p10);
00086      * CAN can2(p30, p29);
00087      *
00088      * char counter = 0;
00089      *
00090      * void send() {
00091      *     if(can1.write(CANMessage(1337, &counter, 1))) {
00092      *         printf("Message sent: %d\n", counter);
00093      *         counter++;
00094      *     }
00095      *     led1 = !led1;
00096      * }
00097      *
00098      * int main() {
00099      *     ticker.attach(&send, 1);
00100      *    CANMessage msg;
00101      *     while(1) {
00102      *         if(can2.read(msg)) {
00103      *             printf("Message received: %d\n\n", msg.data[0]);
00104      *             led2 = !led2;
00105      *         }
00106      *         wait(0.2);
00107      *     }
00108      * }
00109      * @endcode
00110      */
00111     CAN(PinName rd, PinName td);
00112     virtual ~CAN();
00113 
00114     /** Set the frequency of the CAN interface
00115      *
00116      *  @param hz The bus frequency in hertz
00117      *
00118      *  @returns
00119      *    1 if successful,
00120      *    0 otherwise
00121      */
00122     int frequency(int hz);
00123 
00124     /** Write a CANMessage to the bus.
00125      *
00126      *  @param msg The CANMessage to write.
00127      *
00128      *  @returns
00129      *    0 if write failed,
00130      *    1 if write was successful
00131      */
00132     int write(CANMessage msg);
00133 
00134     /** Read a CANMessage from the bus.
00135      *
00136      *  @param msg A CANMessage to read to.
00137      *  @param handle message filter handle (0 for any message)
00138      *
00139      *  @returns
00140      *    0 if no message arrived,
00141      *    1 if message arrived
00142      */
00143     int read(CANMessage &msg, int handle = 0);
00144 
00145     /** Reset CAN interface.
00146      *
00147      * To use after error overflow.
00148      */
00149     void reset();
00150 
00151     /** Puts or removes the CAN interface into silent monitoring mode
00152      *
00153      *  @param silent boolean indicating whether to go into silent mode or not
00154      */
00155     void monitor(bool silent);
00156 
00157     enum Mode {
00158         Reset = 0,
00159         Normal,
00160         Silent,
00161         LocalTest,
00162         GlobalTest,
00163         SilentTest
00164     };
00165 
00166     /** Change CAN operation to the specified mode
00167      *
00168      *  @param mode The new operation mode (CAN::Normal, CAN::Silent, CAN::LocalTest, CAN::GlobalTest, CAN::SilentTest)
00169      *
00170      *  @returns
00171      *    0 if mode change failed or unsupported,
00172      *    1 if mode change was successful
00173      */
00174     int mode(Mode mode);
00175 
00176     /** Filter out incomming messages
00177      *
00178      *  @param id the id to filter on
00179      *  @param mask the mask applied to the id
00180      *  @param format format to filter on (Default CANAny)
00181      *  @param handle message filter handle (Optional)
00182      *
00183      *  @returns
00184      *    0 if filter change failed or unsupported,
00185      *    new filter handle if successful
00186      */
00187     int filter(unsigned int id, unsigned int mask, CANFormat format = CANAny, int handle = 0);
00188 
00189     /** Returns number of read errors to detect read overflow errors.
00190      */
00191     unsigned char rderror();
00192 
00193     /** Returns number of write errors to detect write overflow errors.
00194      */
00195     unsigned char tderror();
00196 
00197     enum IrqType {
00198         RxIrq = 0,
00199         TxIrq,
00200         EwIrq,
00201         DoIrq,
00202         WuIrq,
00203         EpIrq,
00204         AlIrq,
00205         BeIrq,
00206         IdIrq
00207     };
00208 
00209     /** Attach a function to call whenever a CAN frame received interrupt is
00210      *  generated.
00211      *
00212      *  @param func A pointer to a void function, or 0 to set as none
00213      *  @param event Which CAN interrupt to attach the member function to (CAN::RxIrq for message received, CAN::TxIrq for transmitted or aborted, CAN::EwIrq for error warning, CAN::DoIrq for data overrun, CAN::WuIrq for wake-up, CAN::EpIrq for error passive, CAN::AlIrq for arbitration lost, CAN::BeIrq for bus error)
00214      */
00215     void attach(Callback<void()> func, IrqType type=RxIrq);
00216 
00217    /** Attach a member function to call whenever a CAN frame received interrupt
00218     *  is generated.
00219     *
00220     *  @param obj pointer to the object to call the member function on
00221     *  @param method pointer to the member function to be called
00222     *  @param event Which CAN interrupt to attach the member function to (CAN::RxIrq for message received, TxIrq for transmitted or aborted, EwIrq for error warning, DoIrq for data overrun, WuIrq for wake-up, EpIrq for error passive, AlIrq for arbitration lost, BeIrq for bus error)
00223     */
00224     template<typename T>
00225     void attach(T* obj, void (T::*method)(), IrqType type=RxIrq) {
00226         // Underlying call thread safe
00227         attach(Callback<void()>(obj, method), type);
00228     }
00229 
00230    /** Attach a member function to call whenever a CAN frame received interrupt
00231     *  is generated.
00232     *
00233     *  @param obj pointer to the object to call the member function on
00234     *  @param method pointer to the member function to be called
00235     *  @param event Which CAN interrupt to attach the member function to (CAN::RxIrq for message received, TxIrq for transmitted or aborted, EwIrq for error warning, DoIrq for data overrun, WuIrq for wake-up, EpIrq for error passive, AlIrq for arbitration lost, BeIrq for bus error)
00236     */
00237     template<typename T>
00238     void attach(T* obj, void (*method)(T*), IrqType type=RxIrq) {
00239         // Underlying call thread safe
00240         attach(Callback<void()>(obj, method), type);
00241     }
00242 
00243     static void _irq_handler(uint32_t id, CanIrqType type);
00244 
00245 protected:
00246     virtual void lock();
00247     virtual void unlock();
00248     can_t               _can;
00249     Callback<void()>    _irq[9];
00250     PlatformMutex       _mutex;
00251 };
00252 
00253 } // namespace mbed
00254 
00255 #endif
00256 
00257 #endif    // MBED_CAN_H