text: /* mbed Microcontroller Library
   * Copyright (c) 2006-2013 ARM Limited
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  #ifndef MBED_SPI_H
  #define MBED_SPI_H
  
  #include "platform.h"
  
  #if DEVICE_SPI
  
  #include "spi_api.h"
  
  namespace mbed {
  
  /** A SPI Master, used for communicating with SPI slave devices
   *
   * The default format is set to 8-bits, mode 0, and a clock frequency of 1MHz
   *
   * Most SPI devices will also require Chip Select and Reset signals. These
   * can be controlled using <DigitalOut> pins
   *
   * Example:
   * @code
   * // Send a byte to a SPI slave, and record the response
   *
   * #include "mbed.h"
   *
   * SPI device(p5, p6, p7); // mosi, miso, sclk
   *
   * int main() {
   *     int response = device.write(0xFF);
   * }
   * @endcode
   */
  class SPI {
  
  public:
  
      /** Create a SPI master connected to the specified pins
       *
       * Pin Options:
       *  (5, 6, 7) or (11, 12, 13)
       *
       *  mosi or miso can be specfied as NC if not used
       *
       *  @param mosi SPI Master Out, Slave In pin
       *  @param miso SPI Master In, Slave Out pin
       *  @param sclk SPI Clock pin
       */
      SPI(PinName mosi, PinName miso, PinName sclk);
  
      /** Configure the data transmission format
       *
       *  @param bits Number of bits per SPI frame (4 - 16)
       *  @param mode Clock polarity and phase mode (0 - 3)
       *
       * @code
       * mode | POL PHA
       * -----+--------
       *   0  |  0   0
       *   1  |  0   1
       *   2  |  1   0
       *   3  |  1   1
       * @endcode
       */
      void format(int bits, int mode = 0);
  
      /** Set the spi bus clock frequency
       *
       *  @param hz SCLK frequency in hz (default = 1MHz)
       */
      void frequency(int hz = 1000000);
  
      /** Write to the SPI Slave and return the response
       *
       *  @param value Data to be sent to the SPI slave
       *
       *  @returns
       *    Response from the SPI slave
      */
      virtual int write(int value);
  
  protected:
      spi_t _spi;
  
      void aquire(void);
      static SPI *_owner;
      int _bits;
      int _mode;
      int _hz;
  };
  
  } // namespace mbed
  
  #endif
  
  #endif
  