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/platform.h"
00020 
00021 #if DEVICE_CAN
00022 
00023 #include "hal/can_api.h"
00024 #include "platform/Callback.h"
00025 #include "platform/PlatformMutex.h"
00026 
00027 namespace mbed {
00028 /** \addtogroup drivers */
00029 /** @{*/
00030 
00031 /** CANMessage class
00032  *
00033  * @Note Synchronization level: Thread safe
00034  */
00035 class CANMessage : public CAN_Message {
00036 
00037 public:
00038     /** Creates empty CAN message.
00039      */
00040     CANMessage() : CAN_Message() {
00041         len    = 8;
00042         type   = CANData;
00043         format = CANStandard;
00044         id     = 0;
00045         memset(data, 0, 8);
00046     }
00047 
00048     /** Creates CAN message with specific content.
00049      */
00050     CANMessage(int _id, const char *_data, char _len = 8, CANType _type = CANData, CANFormat _format = CANStandard) {
00051       len    = _len & 0xF;
00052       type   = _type;
00053       format = _format;
00054       id     = _id;
00055       memcpy(data, _data, _len);
00056     }
00057 
00058     /** Creates CAN remote message.
00059      */
00060     CANMessage(int _id, CANFormat _format = CANStandard) {
00061       len    = 0;
00062       type   = CANRemote;
00063       format = _format;
00064       id     = _id;
00065       memset(data, 0, 8);
00066     }
00067 };
00068 
00069 /** A can bus client, used for communicating with can devices
00070  */
00071 class CAN {
00072 
00073 public:
00074     /** Creates an CAN interface connected to specific pins.
00075      *
00076      *  @param rd read from transmitter
00077      *  @param td transmit to transmitter
00078      *
00079      * Example:
00080      * @code
00081      * #include "mbed.h"
00082      *
00083      * Ticker ticker;
00084      * DigitalOut led1(LED1);
00085      * DigitalOut led2(LED2);
00086      * CAN can1(p9, p10);
00087      * CAN can2(p30, p29);
00088      *
00089      * char counter = 0;
00090      *
00091      * void send() {
00092      *     if(can1.write(CANMessage(1337, &counter, 1))) {
00093      *         printf("Message sent: %d\n", counter);
00094      *         counter++;
00095      *     }
00096      *     led1 = !led1;
00097      * }
00098      *
00099      * int main() {
00100      *     ticker.attach(&send, 1);
00101      *    CANMessage msg;
00102      *     while(1) {
00103      *         if(can2.read(msg)) {
00104      *             printf("Message received: %d\n\n", msg.data[0]);
00105      *             led2 = !led2;
00106      *         }
00107      *         wait(0.2);
00108      *     }
00109      * }
00110      * @endcode
00111      */
00112     CAN(PinName rd, PinName td);
00113     virtual ~CAN();
00114 
00115     /** Set the frequency of the CAN interface
00116      *
00117      *  @param hz The bus frequency in hertz
00118      *
00119      *  @returns
00120      *    1 if successful,
00121      *    0 otherwise
00122      */
00123     int frequency(int hz);
00124 
00125     /** Write a CANMessage to the bus.
00126      *
00127      *  @param msg The CANMessage to write.
00128      *
00129      *  @returns
00130      *    0 if write failed,
00131      *    1 if write was successful
00132      */
00133     int write(CANMessage msg);
00134 
00135     /** Read a CANMessage from the bus.
00136      *
00137      *  @param msg A CANMessage to read to.
00138      *  @param handle message filter handle (0 for any message)
00139      *
00140      *  @returns
00141      *    0 if no message arrived,
00142      *    1 if message arrived
00143      */
00144     int read(CANMessage &msg, int handle = 0);
00145 
00146     /** Reset CAN interface.
00147      *
00148      * To use after error overflow.
00149      */
00150     void reset();
00151 
00152     /** Puts or removes the CAN interface into silent monitoring mode
00153      *
00154      *  @param silent boolean indicating whether to go into silent mode or not
00155      */
00156     void monitor(bool silent);
00157 
00158     enum Mode {
00159         Reset = 0,
00160         Normal,
00161         Silent,
00162         LocalTest,
00163         GlobalTest,
00164         SilentTest
00165     };
00166 
00167     /** Change CAN operation to the specified mode
00168      *
00169      *  @param mode The new operation mode (CAN::Normal, CAN::Silent, CAN::LocalTest, CAN::GlobalTest, CAN::SilentTest)
00170      *
00171      *  @returns
00172      *    0 if mode change failed or unsupported,
00173      *    1 if mode change was successful
00174      */
00175     int mode(Mode mode);
00176 
00177     /** Filter out incomming messages
00178      *
00179      *  @param id the id to filter on
00180      *  @param mask the mask applied to the id
00181      *  @param format format to filter on (Default CANAny)
00182      *  @param handle message filter handle (Optional)
00183      *
00184      *  @returns
00185      *    0 if filter change failed or unsupported,
00186      *    new filter handle if successful
00187      */
00188     int filter(unsigned int id, unsigned int mask, CANFormat format = CANAny, int handle = 0);
00189 
00190     /** Returns number of read errors to detect read overflow errors.
00191      */
00192     unsigned char rderror();
00193 
00194     /** Returns number of write errors to detect write overflow errors.
00195      */
00196     unsigned char tderror();
00197 
00198     enum IrqType {
00199         RxIrq = 0,
00200         TxIrq,
00201         EwIrq,
00202         DoIrq,
00203         WuIrq,
00204         EpIrq,
00205         AlIrq,
00206         BeIrq,
00207         IdIrq,
00208 
00209         IrqCnt
00210     };
00211 
00212     /** Attach a function to call whenever a CAN frame received interrupt is
00213      *  generated.
00214      *
00215      *  @param func A pointer to a void function, or 0 to set as none
00216      *  @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)
00217      */
00218     void attach(Callback<void()> func, IrqType type=RxIrq);
00219 
00220    /** Attach a member function to call whenever a CAN frame received interrupt
00221     *  is generated.
00222     *
00223     *  @param obj pointer to the object to call the member function on
00224     *  @param method pointer to the member function to be called
00225     *  @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)
00226     */
00227     template<typename T>
00228     void attach(T* obj, void (T::*method)(), IrqType type=RxIrq) {
00229         // Underlying call thread safe
00230         attach(Callback<void()>(obj, method), type);
00231     }
00232 
00233    /** Attach a member function to call whenever a CAN frame received interrupt
00234     *  is generated.
00235     *
00236     *  @param obj pointer to the object to call the member function on
00237     *  @param method pointer to the member function to be called
00238     *  @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)
00239     */
00240     template<typename T>
00241     void attach(T* obj, void (*method)(T*), IrqType type=RxIrq) {
00242         // Underlying call thread safe
00243         attach(Callback<void()>(obj, method), type);
00244     }
00245 
00246     static void _irq_handler(uint32_t id, CanIrqType type);
00247 
00248 protected:
00249     virtual void lock();
00250     virtual void unlock();
00251     can_t               _can;
00252     Callback<void()>    _irq[IrqCnt];
00253     PlatformMutex       _mutex;
00254 };
00255 
00256 } // namespace mbed
00257 
00258 #endif
00259 
00260 #endif    // MBED_CAN_H
00261 
00262 /** @}*/