Diff: I2SSlave.cpp

Revision:

0:e62e06e11575

Child:

5:9dfdde33be7e

diff -r 000000000000 -r e62e06e11575 I2SSlave.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/I2SSlave.cpp	Thu Aug 04 14:53:50 2011 +0000
@@ -0,0 +1,325 @@
+/**
+* @author Daniel Worrall
+*
+* @section LICENSE
+*
+* Copyright (c) 2011 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
+*    I2S port abstraction library cpp file for NXP LPC1768
+*
+*/ 
+#include "I2SSlave.h"
+/*Global Functions*/
+FunctionPointer akjnh3489v8ncv;
+
+extern "C" void I2S_IRQHandler(void){                   //this is a very special function so can remain outside
+    akjnh3489v8ncv.call();
+}
+/******************************************************
+ * Function name:   I2SSlave
+ *
+ * Description:     class constructor
+ *
+ * Parameters:      PinName tx_sda, PinName tx_ws, PinName clk, PinName rx_sda, PinName rx_ws
+ * Returns:         none
+******************************************************/
+//Constructor
+I2SSlave::I2SSlave(PinName tx_sda, PinName tx_ws, PinName clk, PinName rx_sda, PinName rx_ws){
+    storePins_(tx_sda, tx_ws, clk, rx_sda, rx_ws);
+    format(16, STEREO);                                 //this also invokes initialize so no need to call it twice
+}
+//Public functions
+/******************************************************
+ * Function name:   format()
+ *
+ * Description:     sets the bit length for writing and stereo or mono mode
+ *
+ * Parameters:      int bit, bool mode
+ * Returns:         none
+******************************************************/
+void I2SSlave::format(int bit, bool mode){
+    bit_ = bit;
+    mode_ = mode;
+    initialize_(tx_sda_, tx_ws_, clk_, rx_sda_, rx_ws_);
+}
+/******************************************************
+ * Function name:   write()
+ *
+ * Description:     load buffer to write to I2S port
+ *
+ * Parameters:      long *buffer
+ * Returns:         none
+******************************************************/
+void I2SSlave::write(int* buffer, int from, int length){
+    int to = from + length;
+    for(int i = from; i < to; ++i){
+        LPC_I2S->I2STXFIFO = buffer[i];
+    }
+}
+/******************************************************
+ * Function name:   start()
+ *
+ * Description:     attach streamOut_ function to ticker interrupt
+ *
+ * Parameters:      none
+ * Returns:         none
+******************************************************/
+void I2SSlave::start(int mode){
+    switch(mode){
+        case(0):
+             LPC_I2S->I2SIRQ |= (0 << 0);           //disable receive interrupt
+             LPC_I2S->I2SIRQ |= (0 << 1);           //disable transmit interrupt
+             break;
+        case(1):
+            LPC_I2S->I2SIRQ |= (0 << 0);            //disable receive interrupt
+            LPC_I2S->I2SIRQ |= (1 << 1);            //enable transmit interrupt
+            LPC_I2S->I2SIRQ |= (0 << 16);           //set I2STXFIFO depth to 0 words
+            break;
+        case(2):
+            LPC_I2S->I2SIRQ |= (1 << 0);            //enable receive interrupt
+            LPC_I2S->I2SIRQ |= (0 << 1);            //disable transmit interrupt
+            LPC_I2S->I2SIRQ |= (4 << 8);            //set I2SRXFIFO depth to 4 words
+            break;
+        case(3):
+            LPC_I2S->I2SIRQ |= (1 << 0);            //enable receive interrupt
+            LPC_I2S->I2SIRQ |= (4 << 8);            //set I2SRXFIFO depth to 4 words
+            LPC_I2S->I2SIRQ |= (1 << 1);            //enable transmit interrupt
+            LPC_I2S->I2SIRQ |= (0 << 16);           //set I2STXFIFO depth to 0 words
+            break;
+        default:
+            break;
+    }
+    NVIC_SetPriority(I2S_IRQn, 0);
+    NVIC_EnableIRQ(I2S_IRQn);                       //enable I2S interrupt in the NVIC 
+}
+/******************************************************
+ * Function name:   stop()
+ *
+ * Description:     detach streamOut_ from ticker
+ *
+ * Parameters:      none
+ * Returns:         none
+******************************************************/
+void I2SSlave::stop(void){
+    NVIC_DisableIRQ(I2S_IRQn);           
+}
+/******************************************************
+ * Function name:   read()
+ *
+ * Description:     reads FIFORX buffer into [int32_t rxBuffer[8]]
+ *
+ * Parameters:      none
+ * Returns:         none
+******************************************************/
+void I2SSlave::read(void){
+    rxBuffer[0] = LPC_I2S->I2SRXFIFO;
+    rxBuffer[1] = LPC_I2S->I2SRXFIFO;
+    rxBuffer[2] = LPC_I2S->I2SRXFIFO;
+    rxBuffer[3] = LPC_I2S->I2SRXFIFO;
+}
+/******************************************************
+ * Function name:   status_()
+ *
+ * Description:     Read I2SSTATE register
+ *
+ * Parameters:      none
+ * Returns:         int
+******************************************************/
+int I2SSlave::status(void){
+    return LPC_I2S->I2SSTATE;
+}
+//Private functions
+/******************************************************
+ * Function name:   initialize()
+ *
+ * Description:     initialises I2S port 
+ *
+ * Parameters:      PinName tx_sda, PinName tx_ws, PinName clk, PinName rx_sda, PinName rx_ws
+ * Returns:         0 =  successful initialisation
+                   -1 = initialisation failure
+******************************************************/
+int I2SSlave::initialize_(PinName tx_sda, PinName tx_ws, PinName clk, PinName rx_sda, PinName rx_ws){
+    setPins_(tx_sda, tx_ws, clk, rx_sda, rx_ws);        //designate pins
+    LPC_SC->PCONP |= (1 << 27);
+    //configure input/output register
+    format_(bit_, mode_);           
+    //set mbed as SLAVE  
+    LPC_I2S->I2SDAO |= (1 << 5);
+    LPC_I2S->I2SDAI |= (1 << 5);
+    //clock mode
+    setClocks_(4);
+    //set slave mode
+    modeConfig_();
+    //set receiver mode
+    LPC_I2S->I2SRXMODE |= (1 << 1);
+    //slave mode
+    LPC_I2S->I2STXRATE = 0;
+    LPC_I2S->I2SRXRATE = 0;
+    //Start
+    LPC_I2S->I2SDAO |= (0 << 3);          
+    LPC_I2S->I2SDAI |= (0 << 3);
+    LPC_I2S->I2SDAO |= (0 << 4);          
+    LPC_I2S->I2SDAI |= (0 << 4);
+    LPC_I2S->I2SDAO |= (0 << 15);          
+    return 0;
+}
+/******************************************************
+ * Function name:   setClocks_()
+ *
+ * Description:     Set the division setting on the internal clocks
+ *
+ * Parameters:      int divideBy
+ * Returns:         nothing
+******************************************************/
+void I2SSlave::setClocks_(int divideBy){
+    switch(divideBy){
+        case 1:
+            LPC_SC->PCLKSEL1 |= (1 << 22); 
+            LPC_SC->PCLKSEL1 |= (0 << 23);     
+            break;
+        case 2:
+            LPC_SC->PCLKSEL1 |= (0 << 22);
+            LPC_SC->PCLKSEL1 |= (1 << 23);
+            break;
+        case 4:
+            LPC_SC->PCLKSEL1 |= (0 << 22);
+            LPC_SC->PCLKSEL1 |= (0 << 23);
+            break;
+        case 8:
+            LPC_SC->PCLKSEL1 |= (1 << 22);
+            LPC_SC->PCLKSEL1 |= (1 << 23);
+            break;
+        default:
+            break;
+    }
+}
+/******************************************************
+ * Function name:   setPins_()
+ *
+ * Description:     set external pin configuration
+ *
+ * Parameters:      PinName tx_sda, PinName tx_ws, PinName clk, PinName rx_sda, PinName rx_ws
+ * Returns:         none
+******************************************************/
+void I2SSlave::setPins_(PinName tx_sda, PinName tx_ws, PinName clk, PinName rx_sda, PinName rx_ws){
+    if(rx_ws == p29){
+        LPC_PINCON->PINSEL0 |= (1 << 10);   //set p29 as receive word select line
+    } else {
+        LPC_PINCON->PINSEL1 |= (2 << 16);   //set p16 as receive word select line
+    }
+    if(rx_sda == p8){
+        LPC_PINCON->PINSEL0 |= (1 << 12);   //set p8 as receive serial data line
+    } else {
+        LPC_PINCON->PINSEL1 |= (2 << 18);   //set p17 as receive serial data line
+    }
+    LPC_PINCON->PINSEL0 |= (1 << 14);       //set p7 as transmit clock line (only one of these)    
+    LPC_PINCON->PINSEL0 |= (1 << 16);       //set p6 as word select line (only one of these)   
+    LPC_PINCON->PINSEL0 |= (1 << 18);       //set p5 as transmit serial data line (only one of these)
+    LPC_PINCON->PINSEL0 |= (0 << 8);        //clear rx_clk
+}
+/******************************************************
+ * Function name:   format_()
+ *
+ * Description:     sets the bit length for writing and stereo or mono mode
+ *
+ * Parameters:      int bit, bool mode
+ * Returns:         none
+******************************************************/
+void I2SSlave::format_(int bit, bool mode){
+    uint32_t bps= ((bit+1)*8)-1;
+    LPC_I2S->I2SDAO &= (0x00 << 6);
+    LPC_I2S->I2SDAO |= (bps << 6);
+    //set bit length
+    switch(bit){
+        case 8:
+            LPC_I2S->I2SDAO &= 0xfffffffc;
+            break;
+        case 16:
+            LPC_I2S->I2SDAO &= (0 << 1);
+            LPC_I2S->I2SDAO |= (1 << 0);           
+            break;
+        case 32:
+            LPC_I2S->I2SDAO &= (0 << 1);
+            LPC_I2S->I2SDAO |= (3 << 0);
+            break;
+        default:
+            break;
+    }
+    //set audio mode
+    if(mode == STEREO){
+        LPC_I2S->I2SDAO |= (0 << 2);
+    } else {
+        LPC_I2S->I2SDAO |= (1 << 2);
+    }
+    //set transmitter and receiver setting to be the same
+    LPC_I2S->I2SDAI &= (0x00 << 6);
+    LPC_I2S->I2SDAI |= (bps << 6);
+    //set bit length
+    switch(bit){
+        case 8:
+            LPC_I2S->I2SDAI &= 0xfffffffc;
+            break;
+        case 16:
+            LPC_I2S->I2SDAI &= (0 << 1);
+            LPC_I2S->I2SDAI |= (1 << 0);
+            break;
+        case 32:
+            LPC_I2S->I2SDAI &= (0 << 1);
+            LPC_I2S->I2SDAI |= (3 << 0);
+            break;
+        default:
+            break;
+    }
+    //set audio mode
+    if(mode == STEREO){
+        LPC_I2S->I2SDAI |= (0 << 2);
+    } else {
+        LPC_I2S->I2SDAI |= (1 << 2);
+    }
+}
+/******************************************************
+ * Function name:   modeConfig_()
+ *
+ * Description:     Set slave mode
+ *
+ * Parameters:      none
+ * Returns:         none
+******************************************************/
+void I2SSlave::modeConfig_(void){
+    LPC_I2S->I2STXMODE |= (0x0 << 0);
+    LPC_I2S->I2SRXMODE |= (0x0 << 0);
+}
+/******************************************************
+ * Function name:   storePins_()
+ *
+ * Description:     set external pin configuration
+ *
+ * Parameters:      PinName tx_sda, PinName tx_ws, PinName clk, PinName rx_sda, PinName rx_ws
+ * Returns:         none
+******************************************************/
+void I2SSlave::storePins_(PinName tx_sda, PinName tx_ws, PinName clk, PinName rx_sda, PinName rx_ws){
+    tx_sda_ = tx_sda;
+    tx_ws_ = tx_ws;
+    clk_ = clk;
+    rx_sda_ = rx_sda;
+    rx_ws_ = rx_ws;
+}
\ No newline at end of file