From 348b1390f02cbb66e68c140d1d1d3f887355a306 Mon Sep 17 00:00:00 2001
From: Bent Bisballe Nyeng <deva@aasimon.org>
Date: Tue, 12 Aug 2014 19:34:55 +0200
Subject: New I2S and DMA files (dummy).

---
 firmware/drivers/i2s.c | 159 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 159 insertions(+)
 create mode 100644 firmware/drivers/i2s.c

(limited to 'firmware/drivers/i2s.c')

diff --git a/firmware/drivers/i2s.c b/firmware/drivers/i2s.c
new file mode 100644
index 0000000..0085e1d
--- /dev/null
+++ b/firmware/drivers/i2s.c
@@ -0,0 +1,159 @@
+/****************************************************************************
+ *   $Id:: i2s.c 5797 2010-12-03 00:27:00Z usb00423                         $
+ *   Project: NXP LPC17xx I2S example
+ *
+ *   Description:
+ *     This file contains I2S code example which include I2S initialization, 
+ *     I2C interrupt handler, and APIs for I2S access.
+ *
+ ****************************************************************************
+ * Software that is described herein is for illustrative purposes only
+ * which provides customers with programming information regarding the
+ * products. This software is supplied "AS IS" without any warranties.
+ * NXP Semiconductors assumes no responsibility or liability for the
+ * use of the software, conveys no license or title under any patent,
+ * copyright, or mask work right to the product. NXP Semiconductors
+ * reserves the right to make changes in the software without
+ * notification. NXP Semiconductors also make no representation or
+ * warranty that such application will be suitable for the specified
+ * use without further testing or modification.
+****************************************************************************/
+#include <LPC17xx.h>
+//#include "type.h"
+#include "i2s.h"
+#include "dma.h"
+
+/* treat I2S TX and RX as a constant address, make the code and buffer 
+easier for both DMA and non-DMA test */
+volatile uint8_t *I2STXBuffer = (uint8_t *)(DMA_SRC); 
+volatile uint8_t *I2SRXBuffer = (uint8_t *)(DMA_DST);
+volatile uint32_t I2SReadLength = 0;
+volatile uint32_t I2SWriteLength = 0;
+volatile uint32_t I2SRXDone = 0, I2STXDone = 0;
+
+/*****************************************************************************
+** Function name:		I2S_IRQHandler
+**
+** Descriptions:		I2S interrupt handler, only RX interrupt is enabled
+**						for simplicity.
+**
+** parameters:			None
+** Returned value:		None
+** 
+*****************************************************************************/
+void I2S_IRQHandler (void)  
+{
+  uint32_t RxCount = 0;
+
+  if ( LPC_I2S->I2SSTATE & 0x01 )
+  {
+	RxCount = (LPC_I2S->I2SSTATE >> 8) & 0xFF;
+	if ( (RxCount != RXFIFO_EMPTY) && !I2SRXDone )
+	{
+	  while ( RxCount > 0 )
+	  {
+		if ( I2SReadLength == BUFSIZE )
+		{
+		  LPC_I2S->I2SDAI |= ((0x01 << 3) | (0x01 << 4));
+		  LPC_I2S->I2SIRQ &= ~(0x01 << 0);	/* Disable RX */	
+		  I2SRXDone = 1;
+		  break;
+		}
+		else
+		{
+		  I2SRXBuffer[I2SReadLength++] = LPC_I2S->I2SRXFIFO;
+		}
+		RxCount--;
+	  }
+	}
+  }
+  return;
+}
+
+/*****************************************************************************
+** Function name:		I2SStart
+**
+** Descriptions:		Start I2S DAI and DAO
+**
+** parameters:			None
+** Returned value:		None
+** 
+*****************************************************************************/
+void I2SStart( void )
+{
+  uint32_t DAIValue, DAOValue;
+  
+  /* Audio output is the master, audio input is the slave, */
+  /* 16 bit data, stereo, reset, master mode, not mute. */
+  DAOValue = LPC_I2S->I2SDAO;
+  DAIValue = LPC_I2S->I2SDAI;
+  LPC_I2S->I2SDAO = DAOValue & (~((0x01 << 4)|(0x01 <<3)));
+  /* 16 bit data, stereo, reset, slave mode, not mute. */
+  LPC_I2S->I2SDAI = DAIValue & (~((0x01 << 4)|(0x01 <<3)));
+  return;
+}
+
+/*****************************************************************************
+** Function name:		I2SStop
+**
+** Descriptions:		Stop I2S DAI and DAO
+**
+** parameters:			None
+** Returned value:		None
+** 
+*****************************************************************************/
+void I2SStop( void )
+{
+  uint32_t DAIValue, DAOValue;
+
+  /* Stop the I2S to start. Audio output is master, audio input is the slave. */
+  /* 16 bit data, set STOP and RESET bits to reset the channels */
+  DAOValue = LPC_I2S->I2SDAO;
+  /* Switch to master mode, TX channel, no mute */
+  DAOValue &= ~((0x01 << 5)|(0x01 << 15));
+  DAIValue = LPC_I2S->I2SDAI;
+  DAIValue &= ~(0x01 << 15);
+  LPC_I2S->I2SDAO = (0x01 << 4) | (0x01 << 3) | DAOValue;	/* Master */
+  LPC_I2S->I2SDAI = (0x01 << 4) | (0x01 << 3) | DAIValue;	/* Slave */
+  return;
+}
+
+/*****************************************************************************
+** Function name:		I2SInit
+**
+** Descriptions:		Initialize I2S controller
+**
+** parameters:			None
+** Returned value:		true or false, return false if the I2S
+**						interrupt handler was not installed correctly
+** 
+*****************************************************************************/
+void I2SInit( void ) 
+{
+
+  /*enable I2S in the PCONP register. I2S is disabled on reset*/
+  LPC_SC->PCONP |= (1 << 27);
+
+  /*connect the I2S sigals to port pins(P0.4-P0.9)*/
+  LPC_PINCON->PINSEL0 &= ~0x000FFF00;
+  LPC_PINCON->PINSEL0 |= 0x00055500;
+
+  /* Please note, in order to generate accurate TX/RX clock rate for I2S, 
+  PCLK and CCLK needs to be carefully reconsidered. For this test 
+  program, the TX is looped back to RX without external I2S device, 
+  clock rate is not critical in this matter. */
+  LPC_I2S->I2STXRATE = //0x241;
+		(100 << 0) | // Y
+		(49 << 8)   // X
+		;
+
+	//  LPC_I2S->I2SRXRATE = 0x241;
+
+  I2SStop();
+  return;
+}
+
+/******************************************************************************
+**                            End Of File
+******************************************************************************/
+
-- 
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