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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/***************************************************************************
* wm8523.c
*
* Tue Jun 4 20:47:15 CEST 2013
* Copyright 2013 Bent Bisballe Nyeng
* deva@aasimon.org
****************************************************************************/
/*
* This file is part of Pedal2Metal.
*
* Pedal2Metal is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Pedal2Metal is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Pedal2Metal; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include "wm8523.h"
#include <string.h>
#include <lpc17xx_spi.h>
#define WM8523_WRITE 0
#define WM8523_READ 1
static SPI_CFG_Type spi_cfg;
static LPC_SPI_TypeDef spi;
typedef struct __attribute__ ((packed)) {
uint8_t rw:1; ///< See WM8523_WRITE and WM8523_READ
uint8_t reg:7; ///< See page 35 in the WM8523 manual.
uint16_t data;
} WM8523_transfer_t;
void WM8523_Init()
{
// 16 bit data tranfers
spi_cfg.Databit = SPI_DATABIT_16;
// WM8523 samples bits on rising edges. Mode 0 or 3 will work
// http://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus#Clock_polarity_and_phase
// Mode 0
spi_cfg.CPHA = SPI_CPHA_FIRST; // 0
spi_cfg.CPOL = SPI_CPOL_HI; // 0
/*
// Mode 3
spi_cfg.CPHA = SPI_CPHA_SECOND; // 1
spi_cfg.CPOL = SPI_CPOL_LO; // 1
*/
// We are the master
spi_cfg.Mode = SPI_MASTER_MODE;
// We run on a little endian mcu.
spi_cfg.DataOrder = SPI_DATA_LSB_FIRST;
// Se WM8523 manual page 14. Min clock pulse width 40ns ~= 25MHz
spi_cfg.ClockRate = 1000000000; // 1MHz
SPI_Init(&spi, &spi_cfg);
}
static volatile int spi_done = 0;
void spi_mark_as_done()
{
spi_done = 1;
}
static void send(void *data, size_t size)
{
SPI_DATA_SETUP_Type dst;
memset(&dst, 0, sizeof(dst));
dst.rx_data = data;
dst.length = size;
dst.callback = spi_mark_as_done;
spi_done = 0;
SPI_ReadWrite(&spi, &dst, SPI_TRANSFER_INTERRUPT);
while(!spi_done) {}
}
static void receive(void *data, size_t size)
{
// http://anhnvnguyen.blogspot.dk/2010/04/lpc17xx-gpio-basic_05.html
// TODO: set SSEL0 low
// PINSEL3[13:12] = p1.21 (SSEL0)
LPC_PINCON->PINSEL3 &= ~((1<<13)|(1<<12)); // set to 00
SPI_DATA_SETUP_Type dst;
memset(&dst, 0, sizeof(dst));
dst.tx_data = data;
dst.length = size;
dst.callback = spi_mark_as_done;
spi_done = 0;
SPI_ReadWrite(&spi, &dst, SPI_TRANSFER_INTERRUPT);
while(!spi_done) {}
// TODO: set SSEL0 high
}
/**
Volume update registers R06h and R07h are unavailable in SPI control mode.
To use volume update in software control mode, I2C mode must be used.
*/
void WM8523_Configure()
{
WM8523_transfer_t transfer;
transfer.rw = WM8523_READ;
transfer.reg = 0; // R0 read version : 0x8523
transfer.data = 0;
//send(&transfer, sizeof(transfer));
receive(&transfer, sizeof(transfer));
}
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