1 files changed, 126 insertions, 0 deletions
diff --git a/firmware/drivers/wm8523.c b/firmware/drivers/wm8523.c
new file mode 100644
index 0000000..36d293a
--- /dev/null
+++ b/firmware/drivers/wm8523.c
@@ -0,0 +1,126 @@
+/* -*- 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));
+}