Diff: I2S.h

Revision:

0:455d5826751b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/I2S.h	Wed Sep 19 10:53:33 2012 +0000
@@ -0,0 +1,316 @@
+/**
+* @author Giles Barton-Owen
+*
+* @section LICENSE
+*
+* Copyright (c) 2012 mbed
+*
+* 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.
+*
+* @section DESCRIPTION
+*    A I2S library for the LPC1768's built-in I2S peripheral
+*
+*/ 
+
+#include "mbed.h"
+#include "math.h"
+
+#ifndef I2S_H
+#define I2S_H
+
+#define I2S_TRANSMIT     0
+#define I2S_RECEIVE     1
+
+#define I2S_MASTER     0
+#define I2S_SLAVE     1
+
+#define I2S_STEREO     0
+#define I2S_MONO     1
+
+#define I2S_MUTED     1
+#define I2S_UNMUTED 0
+
+#define I2S_4WIRE     1
+#define I2S_3WIRE     0
+
+/** A class to play give access to the I2S library
+ */
+
+class I2S
+{
+
+public:
+
+    /** Create a I2S instance
+     * 
+     * @param rxtx     Set the I2S instance to be transmit or recieve (I2S_TRANSMIT/I2S_RECEIVE)
+     * @param sd    The serial data pin
+     * @param ws    The word select pin
+     * @param clk    The clock pin
+     */
+    I2S(bool rxtx, PinName sd, PinName ws, PinName clk);
+
+    /** Create a I2S instance: Only with the serial data line set. Won't really do much.
+     * 
+     * @param rxtx     Set the I2S instance to be transmit or recieve (I2S_TRANSMIT/I2S_RECEIVE)
+     * @param sd    The serial data pin
+     */
+    I2S(bool rxtx, PinName sd);
+
+    
+    /** Create a I2S instance: Only with serial data line and word select. 
+     * 
+     * @param rxtx     Set the I2S instance to be transmit or recieve (I2S_TRANSMIT/I2S_RECEIVE)
+     * @param sd    The serial data pin
+     * @param ws    The word select pin
+     */
+    I2S(bool rxtx, PinName sd, PinName ws);
+    
+    
+    
+    /** Create a I2S instance: Only with serial data line. Four wire mode means this is functional
+     * 
+     * @param rxtx     Set the I2S instance to be transmit or recieve (I2S_TRANSMIT/I2S_RECEIVE)
+     * @param sd    The serial data pin
+     * @param fourwiremode True means the peripheral is in 4-wire mode. It borrows WS and CLK from the other half
+     */
+    I2S(bool rxtx, PinName sd, bool fourwiremode);
+    
+    /** Create a I2S instance: Only with serial data line and word select line. Four wire mode means this is functional
+     * 
+     * @param rxtx     Set the I2S instance to be transmit or recieve (I2S_TRANSMIT/I2S_RECEIVE)
+     * @param sd    The serial data pin
+     * @param ws    The word select pin
+     * @param fourwiremode True means the peripheral is in 4-wire mode. It borrows WS and CLK from the other half
+     */
+    I2S(bool rxtx, PinName sd, PinName ws, bool fourwiremode);
+
+    /** Destroy the I2S instance
+     */
+    ~I2S();
+
+    /** Write to the FIFO
+     * 
+     * @param buf[] The buffer of values to write: are bit stuffed in fours
+     * @param len    The number of chars to write
+     */
+    void write(char buf[], int len);
+
+    /** Write to the FIFO
+     * 
+     * @param buf[] The buffer of values to write: are bit stuffed automatically
+     * @param len    The number of chars to write
+     */
+    void write(int buf[], int len);
+
+    /** Read the FIFOs contents
+     * 
+     * @return The buffers value.
+     */
+    int read();
+
+    /** Read from the FIFO
+     * 
+     * @param buf[] The buffer of values to read: raw bit shifted
+     * @param len    The number of chars to read
+     */
+    void read(char buf[], int len);
+
+    /** Read from the FIFO
+     * 
+     * @param buf[] The buffer of values to read: sorted to just values
+     * @param len    The number of chars to read
+     */
+    void read(int buf[], int len);
+    
+    /** Get the maximum number of points of data the FIFO could store
+     *
+     * @return The number of points
+     */
+    int max_fifo_points();
+    /** Switch the peripheral on and off
+     *
+     * @param pwr Power status
+     */
+    void power(bool pwr);
+
+    /** Switch the peripheral between master and slave
+     *
+     * @param mastermode The peripherals master/slave status (I2S_MASTER/I2S_SLAVE)
+     */
+    void masterslave(bool mastermode);
+
+    /** Switch the peripheral between different wordsizes
+     *
+     * @param words The number of bits per word: 8,16,32
+     */
+    void wordsize(int words);
+
+    /** Define the mclk frequency
+     *
+     * @param freq The frequency desired for the mclk
+     */
+    void mclk_freq(int freq);
+    
+    /** Define the sample rate
+     *
+     * @param freq The desired sample rate frequency
+     */
+    void frequency(int freq);
+
+    /** Set the level that the fifo interrupts at
+     *
+     * @param level A number between 0 and 7 at which the fifo interrupts
+     */
+    void set_interrupt_fifo_level(int level);
+
+    /** Get the current FIFO level
+     *
+     * @return A number between 0 and 7 the FIFO is currently at
+     */
+    int fifo_level();
+
+    /** Get the current number of samples in the FIFO
+     *
+    * @return A number showing how many samples are in the FIFO
+     */
+    int fifo_points();
+
+    /** Set whether the peripheral is in stereo or mono mode: in mono the perifpheral sends out the same data twice
+     *
+     * @param stereomode Whether the peripheral is in stereo or mono: I2S_STEREO/I2S_MONO
+     */
+    void stereomono(bool stereomode);
+
+    /** Mute the peripheral
+     *
+     */
+    void mute();
+
+    /** Set the mute status of the peripheral
+     *
+     * @param mute_en Set whether the mute is enabled
+     */
+    void mute(bool mute_en);
+
+    /** Stop the peripheral
+     *
+     */
+    void stop();
+
+    /** Start the peripheral
+     *
+     */
+    void start();
+
+    /** Check the Clock and Pin setup went according to plan
+     *
+     * @return Setup okay?
+     */
+    bool setup_ok();
+
+    /** Attach a function to be called when the FIFO triggers
+     *
+     * @param fptr A pointer to the function to be called
+     */
+    void attach(void (*fptr)(void))
+    {
+        if (_rxtx == I2S_TRANSMIT)
+        {
+            I2STXISR.attach(fptr);
+            txisr = true;
+        }
+        else
+        {
+            I2SRXISR.attach(fptr);
+            rxisr = true;
+        }
+    }
+
+    /** Attach a member function to be called when the FIFO triggers
+     *
+     * @param tptr A pointer to the instance of the class
+     * @param mptr A pointer to the member function
+     */
+    template<typename T>
+    void attach(T *tptr, void (T::*mptr)(void))
+    {
+        if (_rxtx == I2S_TRANSMIT)
+        {
+            I2STXISR.attach(tptr, mptr);
+            txisr = true;
+        }
+        else
+        {
+            I2SRXISR.attach(tptr, mptr);
+            rxisr = true;
+        }
+    }
+
+private:
+
+    void mclk_enable(bool mclk_en);
+
+    void write_registers();
+
+    void pin_setup();
+
+    void fraction_estimator(float in, int * num, int * den);
+
+    float mod(float in);
+
+    void defaulter();
+
+    PinName _sd, _ws, _clk, _mclk;
+    bool ws_d, clk_d, mclk_d;
+    bool _rxtx;
+    bool pwr;
+    bool master;
+    int wordwidth;
+    char wordwidth_code;
+    bool mclk_en;
+    int mclk_frequency;
+    int freq;
+    bool stereo;
+    bool muted;
+    bool stopped;
+    int interrupt_fifo_level;
+    int pin_setup_err;
+    int reg_write_err;
+    bool deallocating;
+    int old_freq;
+    
+    bool fourwire;
+
+    int old_pre_num;
+    int old_pre_den;
+    int old_bitrate_div;
+    static void _i2sisr(void);
+
+    static FunctionPointer I2STXISR;
+    static FunctionPointer I2SRXISR;
+
+    static bool txisr;
+    static bool rxisr;
+    
+    void write(int bufr[], int bufl[], int len);
+    void read(int bufr[], int bufl[], int len);
+};
+
+#endif