BufferedSpi.h

00001 
00002 /**
00003  * @file    BufferedSpi.h
00004  * @brief   Software Buffer - Extends mbed SPI functionallity
00005  * @author  Armelle Duboc
00006  * @version 1.0
00007  * @see
00008  *
00009  * Copyright (c) STMicroelectronics 2017
00010  *
00011  * Licensed under the Apache License, Version 2.0 (the "License");
00012  * you may not use this file except in compliance with the License.
00013  * You may obtain a copy of the License at
00014  *
00015  *     http://www.apache.org/licenses/LICENSE-2.0
00016  *
00017  * Unless required by applicable law or agreed to in writing, software
00018  * distributed under the License is distributed on an "AS IS" BASIS,
00019  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00020  * See the License for the specific language governing permissions and
00021  * limitations under the License.
00022  */
00023 
00024 #ifndef BUFFEREDSPI_H
00025 #define BUFFEREDSPI_H
00026 
00027 #include "mbed.h"
00028 #include "MyBuffer.h"
00029 
00030 /** A spi port (SPI) for communication with wifi device
00031  *
00032  * Can be used for Full Duplex communication, or Simplex by specifying
00033  * one pin as NC (Not Connected)
00034  *
00035  * Example:
00036  * @code
00037  *  #include "mbed.h"
00038  *  #include "BufferedSerial.h"
00039  *
00040  *  BufferedSerial pc(USBTX, USBRX);
00041  *
00042  *  int main()
00043  *  {
00044  *      while(1)
00045  *      {
00046  *          Timer s;
00047  *
00048  *          s.start();
00049  *          pc.printf("Hello World - buffered\n");
00050  *          int buffered_time = s.read_us();
00051  *          wait(0.1f); // give time for the buffer to empty
00052  *
00053  *          s.reset();
00054  *          printf("Hello World - blocking\n");
00055  *          int polled_time = s.read_us();
00056  *          s.stop();
00057  *          wait(0.1f); // give time for the buffer to empty
00058  *
00059  *          pc.printf("printf buffered took %d us\n", buffered_time);
00060  *          pc.printf("printf blocking took %d us\n", polled_time);
00061  *          wait(0.5f);
00062  *      }
00063  *  }
00064  * @endcode
00065  */
00066 
00067 /**
00068  *  @class BufferedSpi
00069  *  @brief Software buffers and interrupt driven tx and rx for Serial
00070  */
00071 class BufferedSpi : public SPI {
00072 private:
00073     DigitalOut    nss;
00074     MyBuffer <char>  _txbuf;
00075     uint32_t      _buf_size;
00076     uint32_t      _tx_multiple;
00077     volatile int _timeout;
00078     void txIrq(void);
00079     void prime(void);
00080 
00081     InterruptIn *_datareadyInt;
00082     volatile int _cmddata_rdy_rising_event;
00083     void DatareadyRising(void);
00084     int wait_cmddata_rdy_rising_event(void);
00085     int wait_cmddata_rdy_high(void);
00086 
00087 
00088     Callback<void()> _cbs[2];
00089 
00090     Callback<void()> _sigio_cb;
00091     uint8_t          _sigio_event;
00092 
00093 public:
00094     MyBuffer <char>  _rxbuf;
00095     DigitalIn dataready;
00096     enum IrqType {
00097         RxIrq = 0,
00098         TxIrq,
00099 
00100         IrqCnt
00101     };
00102 
00103     /** Create a BufferedSpi Port, connected to the specified transmit and receive pins
00104      *  @param SPI mosi pin
00105      *  @param SPI miso pin
00106      *  @param SPI sclk pin
00107      *  @param SPI nss pin
00108      *  @param Dataready pin
00109      *  @param buf_size printf() buffer size
00110      *  @param tx_multiple amount of max printf() present in the internal ring buffer at one time
00111      *  @param name optional name
00112     */
00113     BufferedSpi(PinName mosi, PinName miso, PinName sclk, PinName nss, PinName datareadypin, uint32_t buf_size = 2500, uint32_t tx_multiple = 1, const char *name = NULL);
00114 
00115     /** Destroy a BufferedSpi Port
00116      */
00117     virtual ~BufferedSpi(void);
00118 
00119     /** call to SPI frequency Function
00120      */
00121     virtual void frequency(int hz);
00122 
00123     /** clear the transmit buffer
00124      */
00125     virtual void flush_txbuf(void);
00126 
00127     /** call to SPI format function
00128      */
00129     virtual void format(int bits, int mode);
00130 
00131     virtual void enable_nss(void);
00132 
00133     virtual void disable_nss(void);
00134 
00135     /** Check on how many bytes are in the rx buffer
00136      *  @return 1 if something exists, 0 otherwise
00137      */
00138     virtual int readable(void);
00139 
00140     /** Check to see if the tx buffer has room
00141      *  @return 1 always has room and can overwrite previous content if too small / slow
00142      */
00143     virtual int writeable(void);
00144 
00145     /** Get a single byte from the BufferedSpi Port.
00146      *  Should check readable() before calling this.
00147      *  @return A byte that came in on the SPI Port
00148      */
00149     virtual int getc(void);
00150 
00151     /** Write a single byte to the BufferedSpi Port.
00152      *  @param c The byte to write to the SPI Port
00153      *  @return The byte that was written to the SPI Port Buffer
00154      */
00155     virtual int putc(int c);
00156 
00157     /** Write a string to the BufferedSpi Port. Must be NULL terminated
00158      *  @param s The string to write to the Spi Port
00159      *  @return The number of bytes written to the Spi Port Buffer
00160      */
00161     virtual int puts(const char *s);
00162 
00163     /** Write a formatted string to the BufferedSpi Port.
00164      *  @param format The string + format specifiers to write to the Spi Port
00165      *  @return The number of bytes written to the Spi Port Buffer
00166      */
00167     virtual int printf(const char *format, ...);
00168 
00169     /** Write data to the Buffered Spi Port
00170      *  @param s A pointer to data to send
00171      *  @param length The amount of data being pointed to
00172      *  @return The number of bytes written to the Spi Port Buffer
00173      */
00174     virtual ssize_t buffwrite(const void *s, std::size_t length);
00175 
00176     /** Send datas to the Spi port that are already present
00177      *  in the internal _txbuffer
00178      *  @param length
00179      *  @return the number of bytes written on the SPI port
00180      */
00181     virtual ssize_t buffsend(size_t length);
00182 
00183     /** Read data from the Spi Port to the _rxbuf
00184      *  @param max: optional. = max sieze of the input read
00185      *  @return The number of bytes read from the SPI port and written to the _rxbuf
00186      */
00187     virtual ssize_t read();
00188     virtual ssize_t read(uint32_t max);
00189 
00190     /**
00191     * Allows timeout to be changed between commands
00192     *
00193     * @param timeout timeout of the connection in ms
00194     */
00195     void setTimeout(int timeout)
00196     {
00197         /*  this is a safe guard timeout at SPI level in case module is stuck */
00198         _timeout = timeout;
00199     }
00200 
00201     /** Register a callback once any data is ready for sockets
00202      *  @param func     Function to call on state change
00203      */
00204     virtual void sigio(Callback<void()> func);
00205 
00206     /** Attach a function to call whenever a serial interrupt is generated
00207      *  @param func A pointer to a void function, or 0 to set as none
00208      *  @param type Which serial interrupt to attach the member function to (Serial::RxIrq for receive, TxIrq for transmit buffer empty)
00209      */
00210     virtual void attach(Callback<void()> func, IrqType type = RxIrq);
00211 
00212     /** Attach a member function to call whenever a serial interrupt is generated
00213      *  @param obj pointer to the object to call the member function on
00214      *  @param method pointer to the member function to call
00215      *  @param type Which serial interrupt to attach the member function to (Serial::RxIrq for receive, TxIrq for transmit buffer empty)
00216      */
00217     template <typename T>
00218     void attach(T *obj, void (T::*method)(), IrqType type = RxIrq)
00219     {
00220         attach(Callback<void()>(obj, method), type);
00221     }
00222 
00223     /** Attach a member function to call whenever a serial interrupt is generated
00224      *  @param obj pointer to the object to call the member function on
00225      *  @param method pointer to the member function to call
00226      *  @param type Which serial interrupt to attach the member function to (Serial::RxIrq for receive, TxIrq for transmit buffer empty)
00227      */
00228     template <typename T>
00229     void attach(T *obj, void (*method)(T *), IrqType type = RxIrq)
00230     {
00231         attach(Callback<void()>(obj, method), type);
00232     }
00233 };
00234 #endif